bluuebunny/crossref_metadata_2025 huggingface dataset:
On the shear-induced lift in two-way coupled turbulent channel flow laden with heavy particles
Authors: Ruan Yucang , Xiao Zuoli
Published: April 2024

The importance of shear-induced lift, i.e. Saffman lift, is investigated in two-way coupling point-particle direct numerical simulation of turbulent channel flow laden with heavy particles. A new criterion is established for the critical particle diameter normalized by wall viscous length, and the effect of Saffman lift on particle motion can be neglected when the particle diameter is smaller than the critical value. The new criterion agrees well with the numerical results. We further study the influence of Saffman lift on particle motion and turbulence modulation. The results suggest that the Saffman lift will increase near-wall particle velocity and reduce particle accumulation therein. By integrating the particle motion equation, it is demonstrated that the mean particle streamwise velocity is dependent on the particle wall-normal velocity. This theoretically explains why the presence of a wall-normal force alters the streamwise velocity of particles. A theoretical profile of mean particle streamwise velocity at different Stokes numbers is then obtained by introducing the diffusive gradient hypothesis and Prandtl mixing length model. In addition, the present results reveal that the Saffman lift tends to augment the level of turbulence attenuation. The spectral analysis shows that the Saffman lift reduces the turbulent energy of small scales in the buffer region and large structures in the logarithmic region. When the Saffman lift is absent, near-wall particle streaks can be observed in the buffer region, which tend to separate fluid streaks. By contrast, the Saffman lift tends to prevent the formation of near-wall particle streaks.
Active spheroids in viscosity gradients
Authors: Gong Jiahao , Shaik Vaseem A. , Elfring Gwynn J.
Published: April 2024

In this paper, we explore the hydrodynamics of spheroidal active particles in viscosity gradients. This work provides a more accurate modelling approach, in comparison to spherical particles, for anisotropic organisms such as Paramecium swimming through inhomogeneous environments, but more fundamentally examines the influence of particle shape on viscotaxis. We find that spheroidal squirmers generally exhibit dynamics consistent with their spherical analogues, irrespective of the classification of swimmers as pushers, pullers or neutral swimmers. However, the slenderness of the spheroids tends to reduce the impact of viscosity gradients on their dynamics; when a swimmer becomes more slender, the viscosity difference across its body is reduced, which leads to slower reorientation. We also derive the mobility tensor for passive spheroids in viscosity gradients, generalizing previous results for spheres and slender bodies. This work enhances our understanding of how shape factors into the dynamics of passive and active particles in viscosity gradients, and offers new perspectives that could aid the control of both natural and synthetic swimmers in complex fluid environments.
REFLECTIONS ON CYBORG COLLABORATIONS: CROSS-DISCIPLINARY COLLABORATIVE PRACTICE IN TECHNOLOGICALLY-FOCUSED CONTEMPORARY MUSIC
Authors: Kanga Zubin , Dyer Mark , Rowley Caitlin , Packham Jonathan
Published: April 2024

Creating new works combining live musicians with new technologies provides both opportunities and challenges. The Cyborg Soloists research project has commissioned and managed the creation of 46 new works of this type, assembling teams of composers, performers, researchers and technology partners from industry. The majority of these collaborations have been smooth-running and fruitful, but a few have demonstrated complications. This article critically evaluates collaborative methods and methodologies used in the project so far, presenting five case studies involving different types of collaborative work, and exploring the range of professional relationships, the need for different types of expertise within the team and the way technology can act as both a creative catalyst and a source of creative resistance. The conclusions are intended as a toolkit – pragmatic guidelines to inform future practice – and are aimed at artists, technological collaborators, and commissioners and organisations who facilitate these types of creative collaborations.
IT'S NOT ABOUT YOU: DO WE STILL NEED AN ‘ARTISTIC VOICE’?
Authors: Shlomowitz Matthew
Published: April 2024

This article considers the possibility that the emphasis we place on composers developing an artistic voice might be unhelpful for making good pieces. I look at what constitutes an artistic voice and consider pros and cons for having a voice. As an alternative I examine strengths and weaknesses for being a capricious composer, which I define as a willingness to explore different compositional avenues without concern for constructing a consistent body of work. My objective is not to discredit composers who have a strong voice, but rather to loosen the grip of the single-voiced model that dominates the value system of new music.
A novel reinforcement learning framework for disassembly sequence planning using Q-learning technique optimized using an enhanced simulated annealing algorithm
Authors: Chand Mirothali , Ravi Chandrasekar
Published: April 2024

The increase in Electrical and Electronic Equipment (EEE) usage in various sectors has given rise to repair and maintenance units. Disassembly of parts requires proper planning, which is done by the Disassembly Sequence Planning (DSP) process. Since the manual disassembly process has various time and labor restrictions, it requires proper planning. Effective disassembly planning methods can encourage the reuse and recycling sector, resulting in reduction of raw-materials mining. An efficient DSP can lower the time and cost consumption. To address the challenges in DSP, this research introduces an innovative framework based on Q-Learning (QL) within the domain of Reinforcement Learning (RL). Furthermore, an Enhanced Simulated Annealing (ESA) algorithm is introduced to improve the exploration and exploitation balance in the proposed RL framework. The proposed framework is extensively evaluated against state-of-the-art frameworks and benchmark algorithms using a diverse set of eight products as test cases. The findings reveal that the proposed framework outperforms benchmark algorithms and state-of-the-art frameworks in terms of time consumption, memory consumption, and solution optimality. Specifically, for complex large products, the proposed technique achieves a remarkable minimum reduction of 60% in time consumption and 30% in memory usage compared to other state-of-the-art techniques. Additionally, qualitative analysis demonstrates that the proposed approach generates sequences with high fitness values, indicating more stable and less time-consuming disassembles. The utilization of this framework allows for the realization of various real-world disassembly applications, thereby making a significant contribution to sustainable practices in EEE industries.
Impact of COVID-19 on the degree of compliance with hand hygiene: a repeated cross-sectional study
Authors: Guerrero-Soler Maria , Gras-Valentí Paula , Gómez-Sotero Isel Lilibeth , Platas-Abenza Guillermo , Silva-Afonso Raissa de Fátima , Benito-Miralles Carmen-María , Fuster-Pérez Marina , Cartagena-Llopis Lidia , Sánchez-Valero María , Sánchez-Payá José , Chico-Sánchez Pablo
Published: April 2024

Hand hygiene (HH) is the paramount measure used to prevent healthcare-associated infections. A repeated cross-sectional study was undertaken with direct observation of the degree of compliance on HH of healthcare personnel during the SARS-CoV-2 pandemic. Between, 2018–2019, 9,083 HH opportunities were considered, and 5,821 in 2020–2022. Chi squared tests were used to identify associations. The crude and adjusted odds ratios were used along with a logistic regression model for statistical analyses. Compliance on HH increased significantly (p < 0.001) from 54.5% (95% CI: 53.5, 55.5) to 70.1% (95% CI: 68.9, 71.2) during the COVID-19 pandemic. This increase was observed in four of the five key moments of HH established by the World Health Organization (WHO) (p < 0.05), except at moment 4. The factors that were significantly and independently associated with compliance were the time period considered, type of healthcare-personnel, attendance at training sessions, knowledge of HH and WHO guidelines, and availability of hand disinfectant alcoholic solution in pocket format. Highest HH compliance occurred during the COVID-19 pandemic, reflecting a positive change in healthcare-personnel’s behaviour regarding HH recommendations.
An exploratory investigation of functional variation in South Asian online Englishes
Authors: SHAKIR MUHAMMAD
Published: April 2024

This article conducts an exploratory multidimensional (MD) analysis of four interactive online registers, namely newspaper comments, tweets, web forums and text messages, originating from four South Asian countries (Bangladesh, India, Pakistan and Sri Lanka) and two Inner Circle (Kachru 1985) English-speaking countries (UK and USA). A principal component analysis (PCA) has been performed on the interactive registers using linguistic features tagged by a modified version of the MFTE tagger (Le Foll 2021a). The dimensions resulting from the PCA show that nominal, literate and informational features are generally more common in the South Asian data – which represent varieties belonging to the Outer Circle (Kachru 1985). Additionally, different features are used for expressing persuasion or opinion compared to the two reference varieties.
The use of food processing terminology in Australian news media: a content analysis
Authors: Russell Cherie , Sievert Katherine E , Dickie Sarah , Machado Priscila Pereira
Published: April 2024

Objective:

This study aims to determine whether ultra-processed foods (UPFs) are being discussed in news media in Australia and whether this terminology, as described in the NOVA system, is being applied accurately.

Design:

Interpretive content analysis of online and print media articles that mentioned UPFs from 2009 to 2023 in Australia.

Setting:

Australia.

Participants:

Online and print media articles.

Results:

A total of two hundred ninety-eight Australian media articles were captured. A substantial increase in the number of UPF articles was observed between 2017–2019 and 2021–2023. The UPF concept was inaccurately explained or defined in 32 % of the articles and was frequently used interchangeably with other descriptors, such as ‘highly or heavily processed food’, ‘junk food’, ‘unhealthy food’, ‘packaged food’ and ‘discretionary food’. Most of the articles had a health focus; however, sustainability interest increased, particularly in the past 18 months.

Conclusions:

UPFs are increasingly being discussed in news media in Australia; however, the concept is still incorrectly presented in over a third of articles. This highlights the importance of improving the literacy about UPFs to ensure that messages are communicated in a way that is salient, accessible and accurate.
Linking 3D Long‐Term Slow‐Slip Cycle Models With Rupture Dynamics: The Nucleation of the 2014 Mw 7.3 Guerrero, Mexico Earthquake
Authors: Li Duo , Gabriel Alice‐Agnes
Published: March 2024

Slow slip events (SSEs) have been observed in spatial and temporal proximity to megathrust earthquakes in various subduction zones, including the 2014 Mw 7.3 Guerrero, Mexico earthquake which was preceded by a Mw 7.6 SSE. However, the underlying physics connecting SSEs to earthquakes remains elusive. Here, we link 3D slow‐slip cycle models with dynamic rupture simulations across the geometrically complex flat‐slab Cocos plate boundary. Our physics‐based models reproduce key regional geodetic and teleseismic fault slip observations on timescales from decades to seconds. We find that accelerating SSE fronts transiently increase shear stress at the down‐dip end of the seismogenic zone, modulated by the complex geometry beneath the Guerrero segment. The shear stresses cast by the migrating fronts of the 2014 Mw 7.6 SSE are significantly larger than those during the three previous episodic SSEs that occurred along the same portion of the megathrust. We show that the SSE transient stresses are large enough to nucleate earthquake dynamic rupture and affect rupture dynamics. However, additional frictional asperities in the seismogenic part of the megathrust are required to explain the observed complexities in the coseismic energy release and static surface displacements of the Guerrero earthquake. We conclude that it is crucial to jointly analyze the long‐ and short‐term interactions and complexities of SSEs and megathrust earthquakes across several (a)seismic cycles accounting for megathrust geometry. Our study has important implications for identifying earthquake precursors and understanding the link between transient and sudden megathrust faulting processes.
Uplifted Pleistocene Marine Terraces at Active Margins: Modeling Reveals the Effects of Sea Reoccupation and Coseismic Uplift on Uplift Rate Calculation
Authors: Crosetto Silvia , de Montserrat Albert , Oncken Onno
Published: March 2024

Uplifted Pleistocene marine terrace sequences are used to quantify uplift rates along active margins by knowing terrace age and elevation, and sea level (SL) position at the time of terrace formation. When terraces are undated, ages are assigned by correlating terraces at progressively higher elevations with progressively older highstands. Uplift at convergent margins can be constant over time or occur coseismically during upper plate earthquakes. We explore the formation of terrace sequences under conditions of constant and earthquake‐driven uplift by using a forward numerical model. The modeling reveals that terraces are generally abandoned at SL highstands but they are carved during all stands, depending on the time spent within the sea erosional‐depth‐range. Therefore sea reoccupation of a same platform after formation is a common occurrence that decreases with increasing uplift rates, suggesting that most platforms in nature may be in fact polygenetic. Furthermore, the model run time influences the terrace sequences: terraces formed at the beginning of longer runs constitute an ‘inherited morphology’ affecting subsequent sequences. When coseismic uplift is applied, the formation and preservation of terraces for a given average uplift rate depend stochastically on the coseismic displacement ‐ recurrence interval combination in relation to the SL position at the time of the earthquake. These factors significantly contribute to a higher likelihood of non‐preserved terraces along a terrace sequence, which may affect age correlation and, consequently, the resulting uplift rates. Further research is needed to explore the effect of the full seismic cycle in shaping a terrace sequence.
Clumped Isotopes Record a Glacial‐Interglacial Shift in Seasonality of Soil Carbonate Accumulation in the San Luis Valley, Southern Rocky Mountains, USA
Authors: Hudson Adam M. , Kelson Julia R. , Paces James B. , Ruleman Chester A. , Huntington Katharine W. , Schauer Andrew J.
Published: March 2024

Clumped isotope paleothermometry using pedogenic carbonates is a powerful tool for investigating past climate changes. However, location‐specific seasonal patterns of precipitation and soil moisture cause systematic biases in the temperatures they record, hampering comparison of data across large areas or differing climate states. To account for biases, more systematic studies of carbonate forming processes are needed. We measured modern soil temperatures within the San Luis Valley of the Rocky Mountains and compared them to paleotemperatures determined using clumped isotopes. For Holocene‐age samples, clumped isotope results indicate carbonate accumulated at a range of temperatures with site averages similar to the annual mean. Paleotemperatures for late Pleistocene‐age samples (ranging 19–72 ka in age) yielded site averages only 2°C lower, despite evidence that annual temperatures during glacial periods were 5–9°C colder than modern. We use a 1D numerical model of soil physics to support the idea that differences in hydrologic conditions in interglacial versus glacial periods promote differences in the seasonal distribution of soil carbonate accumulation. Model simulations of modern (Holocene) conditions suggest that soil drying under low soil pCO2 favors year‐round carbonate accumulation in this region but peaking during post‐monsoon soil drying. During a “glacial” simulation with lowered temperatures and added snowpack, more carbonate accumulation shifted to the summer season. These experiments show that changing hydrologic regimes could change the seasonality of carbonate accumulation, which in this study blunts the use of clumped isotopes to quantify glacial‐interglacial temperature changes. This highlights the importance of understanding seasonal biases of climate proxies for accurate paleoenvironmental reconstruction.
Halogen (F, Cl, Br, and I) Devolatilization During Prograde Subduction: Insights From Western Alps Ophiolites
Authors: Beaudoin G. M. , Barnes J. D. , Orlandini O. F. , Chatterjee R. , Stockli D. F. , John T.
Published: April 2024

In order to examine the progressive chemical evolution of halogens (F, Cl, Br, I) in altered ocean crust (AOC) during prograde subduction, this study compares bulk and in situ halogen concentrations in mafic samples from three petrogenetically related exhumed terrains in the Western Alps (the Chenaillet ophiolite, the Queyras ophiolites of the Schistes Lustrés, and the Monviso ophiolite). Samples from the Chenaillet ophiolite represent oceanic crust unaffected by metamorphic halogen loss and define a protolith halogen content (122 μg/g F, 29 μg/g Cl, 82 ng/g Br, and 98 ng/g I). Samples from the Queyras ophiolites experienced blueschist facies conditions, undergoing recrystallization and halogen loss (74 μg/g F, 19 μg/g Cl, 70 ng/g Br, and 63 ng/g I). Eclogite facies samples from the Monviso meta‐ophiolite exhibit markedly reduced Cl (8 μg/g Cl) and Br (42 ng/g Br) contents relative to samples from Chenaillet and Queyras. Using electron probe microanalysis (EPMA), F and Cl host minerals (e.g., amphibole, chlorite, epidote) are identified and characterized in selected samples, showing a broad distribution of F and Cl, lending support to the view that halogen devolatilization in the subducting slab occurs continuously and is not dependent on the breakdown of a particular phase. In situ Cl concentrations decrease significantly between sub‐greenschist and blueschist assemblages. Fluorine is retained within subducting AOC and is decoupled from the heavy halogens (Cl, Br, I), which undergo continuous devolatilization during prograde metamorphism.
Semi‐Quantification of the Calcium Carbonate in Marine Sediments by Visible and Near‐Infrared Diffuse Reflectance Spectroscopy
Authors: Cao Wei , Liu Qingsong , Jiang Zhaoxia , Zhong Yi , Gai Congcong , Wang Haosen , Wang Dunfan
Published: March 2024

As one of the most widespread components in marine sediments, calcium carbonate (CaCO3) plays a crucial role in the global carbon cycle and climate changes. To efficiently semi‐quantify the CaCO3 concentration, a more effective, non‐destructive, economic, and accurate technique is required. Diffuse reflectance spectroscopy (DRS) has been widely used for the detection and quantification of minerals but has been less studied for CaCO3. This study synthesized a series of samples with well‐determined content of CaCO3 to analyze the visible and near‐infrared DRS characteristics. Results show that the intensity of the second derivative of Kubelka‐Munk (K‐M) remission functions of the DRS spectra at 2,340 nm (I2340) is linearly correlated with the CaCO3 content. Then, the new proxy I2340 was applied for marine sediments from the Pacific Ocean with known CaCO3 concentrations determined previously by chemical methods, and the robustness of the I2340 as the proxy for CaCO3 concentration was attested.
Mesoscale Eddy Variability Enhances Fixed Nitrogen Loss and Suppresses Nitrous Oxide Production in Oxygen Minimum Zones
Authors: McCoy Daniel , Damien Pierre , Yang Simon , Bianchi Daniele
Published: April 2024

Within oxygen minimum zones, anaerobic processes transform bioavailable nitrogen (N) into the gases dinitrogen (N2) and nitrous oxide (N2O), a potent greenhouse gas. Mesoscale eddies in these regions create heterogeneity in dissolved N tracers and O2 concentrations, influencing nonlinear N cycle reactions that depend on them. Here, we use an eddy‐resolving model of the Eastern Tropical South Pacific to show that eddies enhance N2 production by between 43% and 64% at the expense of reducing N2O production by between 94% and 104% due to both the steep increase of progressive denitrification steps at vanishing oxygen, and the more effective inhibition of N2O consumption relative to production. Our findings reveal the critical role of eddies in shaping the N cycle of oxygen minimum zones, which is not currently represented by coarse models used for climate studies.
Seasonal and Diurnal Variations of Dust Storms in Martian Year 36 Based on the EMM‐EXI Database
Authors: Guha Bijay Kumar , Gebhardt Claus , Young Roland M. B. , Wolff Michael J. , Montabone Luca
Published: March 2024

The Emirates eXploration Imager (EXI) onboard the Emirates Mars Mission (EMM) is a dual‐telescope camera system capable of observing various Martian atmospheric phenomena. The spacecraft's unique orbit allows the EXI to capture full disk views of Mars at a time step of hours or less, with a resolution of ∼2–4 km per pixel (in the nadir‐looking direction) in both visible and UV channels. Leveraging these unparalleled observations, we conducted a comprehensive analysis of dust storms for Martian year (MY) 36, in alignment with EMM's scientific goals. This study involved the compilation of a dust storm database covering one MY using EMM‐EXI images. This database contains essential information such as the start and end times of dust storms, their areal extent, and the latitude and longitude of the centroid. Furthermore, we devote significant attention to characterizing sub‐diurnal variability, a facet not previously emphasized, by meticulously tracking dust storm evolution across multiple local times. Our analysis also delves into the origins, pathways, and morphological attributes of these dust storms. Overall, we catalog a total of 98 dust storms until the end of MY 36 (excluding the polar cap edge dust storms) since the beginning of the EMM science phase, and discuss their diurnal, seasonal, and spatial variability while comparing with some previously published findings. Additionally, we address the potential impact of EMM's coverage on the variability of these dust storms, drawing insights from a well‐established multi‐year database prepared from the observations of the Mars Color Imager onboard the Mars Reconnaissance Orbiter.
Evaluation of Selected Sentinel‐2 Remotely Sensed Vegetation Indices and MODIS GPP in Representing Productivity in Semi‐Arid South African Ecosystems
Authors: Maluleke Amukelani , Feig Gregor , Brümmer Christian , Rybchak Oksana , Midgley Guy
Published: April 2024

The ability to validate satellite observations with ground‐based data sets is vital for the spatiotemporal assessment of productivity trends in semi‐arid ecosystems. Modeling ecosystem scale parameters such as gross primary production (GPP) with the combination of satellite and ground‐based data however requires a comprehensive understanding of the associated drivers of how the carbon balance of these ecosystems is impacted under climate change. We used GPP estimates from the partitioning of net ecosystem measurements (net ecosystem exchange) from three Eddy Covariance (EC) flux tower sites and applied linear regressions to evaluate the ability of Sentinel‐2 vegetation indices (VIs) retrieved from Google Earth Engine to estimate GPP in semi‐arid ecosystems. The Sentinel‐2 normalized difference vegetation index (NDVI), enhanced vegetation index (EVI) and the land surface water index (LSWI) were each assessed separately, and also in combination with selected meteorological variables (incoming radiation, soil water content, air temperature, vapor pressure deficit) using a bi‐directional stepwise linear regression to test whether this can improve GPP estimates. The performance of the MOD17AH2 8‐day GPP was also tested across the sites. NDVI, EVI and LSWI were able to track the phase and amplitude patterns of EC estimated gross primary production (GPPEC) across all sites, albeit with phase delays observed especially at the Benfontein Savanna site (Ben_Sav). In all cases, the VI estimates improved with the addition of meteorological variables except for LSWI at Middleburg Karoo (Mid_Kar). The least improvement in R2 was observed in all EVI‐based estimates—indicating the suitability of EVI as a single VI to estimate GPP. Our results suggest that while productivity assessments using a single VI may be more favorable, the inclusion of meteorological variables can be applied to improve single VIs estimates to accurately detect and characterize changes in GPP. In addition, we found that standard MODIS products better represent the phase than amplitude of productivity in semi‐arid ecosystems, explaining between 68% and 83% of GPP variability.
Cohort Marsh Equilibrium Model (CMEM): History, Mathematics, and Implementation
Authors: Vahsen M. L. , Todd‐Brown K. E. O. , Hicks J. , Pilyugin S. S. , Morris J. T. , Holmquist J. R.
Published: April 2024

Marsh accretion models predict the resiliency of coastal wetlands and their ability to store carbon in the face of accelerating sea level rise. Most existing marsh accretion models are derived from two parent models: the Marsh Equilibrium Model, which formalizes the biophysical relationships between sea level rise, dominant macrophyte growth, and elevation change; and the Cohort Theory Model, which formalizes how carbon mass pools belowground contribute to soil volume expansion over time. While there are several existing marsh accretion models, the application of these models by a broader base of researchers and practitioners is hindered because of (a) limited descriptions of how empirically derived ecological mechanism informed the development of these models, (b) limitations in the ability to apply models to geographies with variable tidal regimes, and (c) a lack of open‐source code to apply models. Here, we provide for the first time an explicit description of a mathematical version of the Cohort Theory Model and a numerical version of a combined model: the Cohort Marsh Equilibrium Model (CMEM) with an accompanying open‐source R package, rCMEM. We show that, through this “depth‐aware” model, we can capture how tidal variation impacts broad patterns of marsh accretion and carbon sequestration across the United States. The application of this model will likely be imperative in predicting the fate and state of coastal wetlands and the ecosystem services they provide in an era of rapid environmental change.
Groundwater Circulation Within the Mountain Block: Combining Flow and Transport Models With Magnetotelluric Observations to Untangle Its Nested Nature
Authors: Gonzalez‐Duque D. , Gomez‐Velez J. D. , Person M. A. , Kelley S. , Key K. , Lucero D.
Published: April 2024

Mountains are vital water sources for humans and ecosystems, continuously replenishing lowland aquifers through surface runoff and mountain recharge. Quantifying these fluxes and their relative importance is essential for sustainable water resource management. However, our mechanistic understanding of the flow and transport processes determining the connection between the mountain block and the basin aquifer remains limited. Traditional conceptualizations assume groundwater circulation within the mountain block is predominantly shallow. This view neglects the role of deep groundwater flowpaths significantly contributing to the water, solute, and energy budgets. Overcoming these limitations requires a holistic characterization of the multiscale nature of groundwater flow along the mountain‐to‐valley continuum. As a proof‐of‐concept, we use a coupled groundwater flow and transport model to design a series of numerical experiments that explore the role of geology, topography, and weathering rates in groundwater circulation and their resulting resistivity patterns. Our results show that accumulating solutes near stagnation zones create contrasting electrical resistivity patterns that separate local, intermediate, and regional flow cells, presenting a target for magnetotelluric observations. To demonstrate the sensitivity of magnetotelluric data to features in our resistivity models, we use the MARE2DEM electromagnetic modeling code to perform forward and inverse simulations. This study highlights the potential of magnetotelluric surveys to image the resistivity structure resulting from multiscale groundwater circulation through relatively impervious crystalline basement rocks in mountainous terrains. This capability could change our understanding of the critical zone, offering a holistic perspective that includes deep groundwater circulation and its role in conveying solutes and energy.
Rewiring the Carbon Cycle: A Theoretical Framework for Animal‐Driven Ecosystem Carbon Sequestration
Authors: Rizzuto Matteo , Leroux Shawn J. , Schmitz Oswald J.
Published: April 2024

Most carbon cycle models do not consider animal‐mediated effects, focusing instead on carbon exchanges among plants, microbes, and the atmosphere. Yet, a growing body of empirical evidence from diverse ecosystems points to pervasive animal effects on ecosystem carbon cycling and shows that ignoring them could lead to misrepresentation of an ecosystem's carbon cycle. We develop a new theoretical framework to account for animal effects on ecosystem carbon cycling. We combine a classic ecosystem compartment modeling approach with a classic carbon model to account for carbon flux and storage among plant, animal, and soil microbial trophic compartments. We show, by way of numerical analyses of steady state conditions across three competing scenarios, that animal presence alters the dominant pathways of control over carbon storage and capture. This altered control arises via direct, consumptive effects and especially via indirect, non‐consumptive pathways by instigating faster nutrient recycling. This leads to a quantitative change in the ecosystem's carbon balance, enhancing the amount of carbon captured and stored in the ecosystem. Further, the indirect pathways appear especially important in enabling these effects because of their sensitivity to the structure of the ecosystem's food chain. The modeling shows that animals could play a larger role in ecosystem carbon cycle than previously thought. Our framework provides further guidance for empirical research aimed at quantifying animal‐mediated control of carbon cycling and to inform the development of nature‐based climate change solutions that leverage animal influence on the carbon cycle to help mitigate climate change.
Cargo specificity, regulation, and therapeutic potential of cytoplasmic dynein
Authors: Park Jin-Gyeong , Jeon Hanul , Hwang Kwang Yeon , Cha Sun-Shin , Han Rafael T. , Cho Hyesung , Lee In-Gyun
Published: April 2024

Intracellular retrograde transport in eukaryotic cells relies exclusively on the molecular motor cytoplasmic dynein 1. Unlike its counterpart, kinesin, dynein has a single isoform, which raises questions about its cargo specificity and regulatory mechanisms. The precision of dynein-mediated cargo transport is governed by a multitude of factors, including temperature, phosphorylation, the microtubule track, and interactions with a family of activating adaptor proteins. Activating adaptors are of particular importance because they not only activate the unidirectional motility of the motor but also connect a diverse array of cargoes with the dynein motor. Therefore, it is unsurprising that dysregulation of the dynein-activating adaptor transport machinery can lead to diseases such as spinal muscular atrophy, lower extremity, and dominant. Here, we discuss dynein motor motility within cells and in in vitro, and we present several methodologies employed to track the motion of the motor. We highlight several newly identified activating adaptors and their roles in regulating dynein. Finally, we explore the potential therapeutic applications of manipulating dynein transport to address diseases linked to dynein malfunction.
Ceramide kinase-mediated C1P metabolism attenuates acute liver injury by inhibiting the interaction between KEAP1 and NRF2
Authors: Dong Wei , Li Qing , Lu Xing , Lan Jianfeng , Qiu Zhidong , Wang Xuehong , Wang Junnan , Zheng Xiaojiao , Chen Sifan , Zhang Chong , Jin Junfei
Published: April 2024

Acute liver injury is the basis of the pathogenesis of diverse liver diseases. However, the mechanism underlying liver injury is complex and not completely understood. In our study, we revealed that CERK, which phosphorylates ceramide to produce ceramide-1-phosphate (C1P), was the sphingolipid pathway-related protein that had the most significantly upregulated expression during acute liver injury. A functional study confirmed that CERK and C1P attenuate hepatic injury both in vitro and in vivo through antioxidant effects. Mechanistic studies have shown that CERK and C1P positively regulate the protein expression of NRF2, which is a crucial protein that helps maintain redox homeostasis. Furthermore, our results indicated that C1P disrupted the interaction between NRF2 and KEAP1 by competitively binding to KEAP1, which allowed for the nuclear translocation of NRF2. In addition, pull-down assays and molecular docking analyses revealed that C1P binds to the DGR domain of KEAP1, which allows it to maintain its interaction with NRF2. Importantly, these findings were verified in human primary hepatocytes and a mouse model of hepatic ischemia‒reperfusion injury. Taken together, our findings demonstrated that CERK-mediated C1P metabolism attenuates acute liver injury via the binding of C1P to the DGR domain of KEAP1 and subsequently the release and nuclear translocation of NRF2, which activates the transcription of cytoprotective and antioxidant genes. Our study suggested that the upregulation of CERK and C1P expression may serve as a potential antioxidant strategy to alleviate acute liver injury.
Dysregulation of Wnt/β-catenin signaling contributes to intestinal inflammation through regulation of group 3 innate lymphoid cells
Authors: Hao Jiacheng , Liu Chang , Gu Zhijie , Yang Xuanming , Lan Xun , Guo Xiaohuan
Published: April 2024

RORγt+ group 3 innate lymphoid cells (ILC3s) are essential for intestinal homeostasis. Dysregulation of ILC3s has been found in the gut of patients with inflammatory bowel disease and colorectal cancer, yet the specific mechanisms still require more investigation. Here we observe increased β-catenin in intestinal ILC3s from inflammatory bowel disease and colon cancer patients compared with healthy donors. In contrast to promoting RORγt expression in T cells, activation of Wnt/β-catenin signaling in ILC3s suppresses RORγt expression, inhibits its proliferation and function, and leads to a deficiency of ILC3s and subsequent intestinal inflammation in mice. Activated β-catenin and its interacting transcription factor, TCF-1, cannot directly suppress RORγt expression, but rather alters global chromatin accessibility and inhibits JunB expression, which is essential for RORγt expression in ILC3s. Together, our findings suggest that dysregulated Wnt/β-catenin signaling impairs intestinal ILC3s through TCF-1/JunB/RORγt regulation, further disrupting intestinal homeostasis, and promoting inflammation and cancer.
Intrathecal delivery of adipose-derived mesenchymal stem cells in traumatic spinal cord injury: Phase I trial
Authors: Bydon Mohamad , Qu Wenchun , Moinuddin F. M. , Hunt Christine L. , Garlanger Kristin L. , Reeves Ronald K. , Windebank Anthony J. , Zhao Kristin D. , Jarrah Ryan , Trammell Brandon C. , El Sammak Sally , Michalopoulos Giorgos D. , Katsos Konstantinos , Graepel Stephen P. , Seidel-Miller Kimberly L. , Beck Lisa A. , Laughlin Ruple S. , Dietz Allan B.
Published: April 2024

Abstract

Intrathecal delivery of autologous culture-expanded adipose tissue-derived mesenchymal stem cells (AD-MSC) could be utilized to treat traumatic spinal cord injury (SCI). This Phase I trial (ClinicalTrials.gov: NCT03308565) included 10 patients with American Spinal Injury Association Impairment Scale (AIS) grade A or B at the time of injury. The study’s primary outcome was the safety profile, as captured by the nature and frequency of adverse events. Secondary outcomes included changes in sensory and motor scores, imaging, cerebrospinal fluid markers, and somatosensory evoked potentials. The manufacturing and delivery of the regimen were successful for all patients. The most commonly reported adverse events were headache and musculoskeletal pain, observed in 8 patients. No serious AEs were observed. At final follow-up, seven patients demonstrated improvement in AIS grade from the time of injection. In conclusion, the study met the primary endpoint, demonstrating that AD-MSC harvesting and administration were well-tolerated in patients with traumatic SCI.
A negative feedback loop between TET2 and leptin in adipocyte regulates body weight
Authors: Zeng Qin , Song Jianfeng , Sun Xiaoxiao , Wang Dandan , Liao Xiyan , Ding Yujin , Hu Wanyu , Jiao Yayi , Mai Wuqian , Aini Wufuer , Wang Fanqi , Zhou Hui , Xie Limin , Mei Ying , Tang Yuan , Xie Zhiguo , Wu Haijing , Liu Wei , Deng Tuo
Published: April 2024

Ten-eleven translocation (TET) 2 is an enzyme that catalyzes DNA demethylation to regulate gene expression by oxidizing 5-methylcytosine to 5-hydroxymethylcytosine, functioning as an essential epigenetic regulator in various biological processes. However, the regulation and function of TET2 in adipocytes during obesity are poorly understood. In this study, we demonstrate that leptin, a key adipokine in mammalian energy homeostasis regulation, suppresses adipocyte TET2 levels via JAK2-STAT3 signaling. Adipocyte Tet2 deficiency protects against high-fat diet-induced weight gain by reducing leptin levels and further improving leptin sensitivity in obese male mice. By interacting with C/EBPα, adipocyte TET2 increases the hydroxymethylcytosine levels of the leptin gene promoter, thereby promoting leptin gene expression. A decrease in adipose TET2 is associated with obesity-related hyperleptinemia in humans. Inhibition of TET2 suppresses the production of leptin in mature human adipocytes. Our findings support the existence of a negative feedback loop between TET2 and leptin in adipocytes and reveal a compensatory mechanism for the body to counteract the metabolic dysfunction caused by obesity.
Intelligent wireless power transfer via a 2-bit compact reconfigurable transmissive-metasurface-based router
Authors: Li Wenzhi , Yu Qiyue , Qiu Jing Hui , Qi Jiaran
Published: April 2024

With the rapid development of the Internet of Things, numerous devices have been deployed in complex environments for environmental monitoring and information transmission, which brings new power supply challenges. Wireless power transfer is a promising solution since it enables power delivery without cables, providing well-behaved flexibility for power supplies. Here we propose a compact wireless power transfer framework. The core components of the proposed framework include a plane-wave feeder and a transmissive 2-bit reconfigurable metasurface-based beam generator, which constitute a reconfigurable power router. The combined profile of the feeder and the beam generator is 0.8 wavelengths. In collaboration with a deep-learning-driven environment sensor, the router enables object detection and localization, and intelligent wireless power transfer to power-consuming targets, especially in dynamic multitarget environments. Experiments also show that the router is capable of simultaneous wireless power and information transfer. Due to the merits of low cost and compact size, the proposed framework may boost the commercialization of metasurface-based wireless power transfer routers.
Defect-induced triple synergistic modulation in copper for superior electrochemical ammonia production across broad nitrate concentrations
Authors: Zhang Bocheng , Dai Zechuan , Chen Yanxu , Cheng Mingyu , Zhang Huaikun , Feng Pingyi , Ke Buqi , Zhang Yangyang , Zhang Genqiang
Published: April 2024

Nitrate can be electrochemically degraded to produce ammonia while treating sewage while it remains grand challenge to simultaneously realize high Faradaic efficiency and production rate over wide-range concentrations in real wastewater. Herein, we report the defect-rich Cu nanowire array electrode generated by in-situ electrochemical reduction, exhibiting superior performance in the electrochemical nitrate reduction reaction benefitting from the triple synergistic modulation. Notably, the defect-rich Cu nanowire array electrode delivers current density ranging from 50 to 1100 mA cm−2 across wide nitrate concentrations (1–100 mM) with Faradaic efficiency over 90%. Operando Synchrotron radiation Fourier Transform Infrared Spectroscopy and theoretical calculations revealed that the defective Cu sites can simultaneously enhance nitrate adsorption, promote water dissociation and suppress hydrogen evolution. A two-electrode system integrating nitrate reduction reaction in industrial wastewater with glycerol oxidation reaction achieves current density of 550 mA cm−2 at −1.4 V with 99.9% ammonia selectivity and 99.9% nitrate conversion with 100 h stability, demonstrating outstanding practicability.
Native-state proteomics of Parvalbumin interneurons identifies unique molecular signatures and vulnerabilities to early Alzheimer’s pathology
Authors: Kumar Prateek , Goettemoeller Annie M. , Espinosa-Garcia Claudia , Tobin Brendan R. , Tfaily Ali , Nelson Ruth S. , Natu Aditya , Dammer Eric B. , Santiago Juliet V. , Malepati Sneha , Cheng Lihong , Xiao Hailian , Duong Duc D. , Seyfried Nicholas T. , Wood Levi B. , Rowan Matthew J. M. , Rangaraju Srikant
Published: April 2024

Dysfunction in fast-spiking parvalbumin interneurons (PV-INs) may represent an early pathophysiological perturbation in Alzheimer’s Disease (AD). Defining early proteomic alterations in PV-INs can provide key biological and translationally-relevant insights. We used cell-type-specific in-vivo biotinylation of proteins (CIBOP) coupled with mass spectrometry to obtain native-state PV-IN proteomes. PV-IN proteomic signatures include high metabolic and translational activity, with over-representation of AD-risk and cognitive resilience-related proteins. In bulk proteomes, PV-IN proteins were associated with cognitive decline in humans, and with progressive neuropathology in humans and the 5xFAD mouse model of Aβ pathology. PV-IN CIBOP in early stages of Aβ pathology revealed signatures of increased mitochondria and metabolism, synaptic and cytoskeletal disruption and decreased mTOR signaling, not apparent in whole-brain proteomes. Furthermore, we demonstrated pre-synaptic defects in PV-to-excitatory neurotransmission, validating our proteomic findings. Overall, in this study we present native-state proteomes of PV-INs, revealing molecular insights into their unique roles in cognitive resiliency and AD pathogenesis.
The Miocene primate Pliobates is a pliopithecoid
Authors: Bouchet Florian , Zanolli Clément , Urciuoli Alessandro , Almécija Sergio , Fortuny Josep , Robles Josep M. , Beaudet Amélie , Moyà-Solà Salvador , Alba David M.
Published: April 2024

The systematic status of the small-bodied catarrhine primate Pliobates cataloniae, from the Miocene (11.6 Ma) of Spain, is controversial because it displays a mosaic of primitive and derived features compared with extant hominoids (apes and humans). Cladistic analyses have recovered Pliobates as either a stem hominoid or as a pliopithecoid stem catarrhine (i.e., preceding the cercopithecoid–hominoid divergence). Here, we describe additional dental remains of P. cataloniae from another locality that display unambiguous synapomorphies of crouzeliid pliopithecoids. Our cladistic analyses support a close phylogenetic link with poorly-known small crouzeliids from Europe based on (cranio)dental characters but recover pliopithecoids as stem hominoids when postcranial characters are included. We conclude that Pliobates is a derived stem catarrhine that shows postcranial convergences with modern apes in the elbow and wrist joints—thus clarifying pliopithecoid evolution and illustrating the plausibility of independent acquisition of postcranial similarities between hylobatids and hominids.
Deuteration-enhanced neutron contrasts to probe amorphous domain sizes in organic photovoltaic bulk heterojunction films
Authors: Cai Guilong , Li Yuhao , Fu Yuang , Yang Hua , Mei Le , Nie Zhaoyang , Li Tengfei , Liu Heng , Ke Yubin , Wang Xun-Li , Brédas Jean-Luc , Tang Man-Chung , Chen Xiankai , Zhan Xiaowei , Lu Xinhui
Published: March 2024

An organic photovoltaic bulk heterojunction comprises of a mixture of donor and acceptor materials, forming a semi-crystalline thin film with both crystalline and amorphous domains. Domain sizes critically impact the device performance; however, conventional X-ray scattering techniques cannot detect the contrast between donor and acceptor materials within the amorphous intermixing regions. In this study, we employ neutron scattering and targeted deuteration of acceptor materials to enhance the scattering contrast by nearly one order of magnitude. Remarkably, the PM6:deuterated Y6 system reveals a new length scale, indicating short-range aggregation of Y6 molecules in the amorphous intermixing regions. All-atom molecular dynamics simulations confirm that this short-range aggregation is an inherent morphological advantage of Y6 which effectively assists charge extraction and suppresses charge recombination as shown by capacitance spectroscopy. Our findings uncover the amorphous nanomorphology of organic photovoltaic thin films, providing crucial insights into the morphology-driven device performance.
Loss-of-function mutation in PRMT9 causes abnormal synapse development by dysregulation of RNA alternative splicing
Authors: Shen Lei , Ma Xiaokuang , Wang Yuanyuan , Wang Zhihao , Zhang Yi , Pham Hoang Quoc Hai , Tao Xiaoqun , Cui Yuehua , Wei Jing , Lin Dimitri , Abeywanada Tharindumala , Hardikar Swanand , Halabelian Levon , Smith Noah , Chen Taiping , Barsyte-Lovejoy Dalia , Qiu Shenfeng , Xing Yi , Yang Yanzhong
Published: April 2024

Protein arginine methyltransferase 9 (PRMT9) is a recently identified member of the PRMT family, yet its biological function remains largely unknown. Here, by characterizing an intellectual disability associated PRMT9 mutation (G189R) and establishing a Prmt9 conditional knockout (cKO) mouse model, we uncover an important function of PRMT9 in neuronal development. The G189R mutation abolishes PRMT9 methyltransferase activity and reduces its protein stability. Knockout of Prmt9 in hippocampal neurons causes alternative splicing of ~1900 genes, which likely accounts for the aberrant synapse development and impaired learning and memory in the Prmt9 cKO mice. Mechanistically, we discover a methylation-sensitive protein–RNA interaction between the arginine 508 (R508) of the splicing factor 3B subunit 2 (SF3B2), the site that is exclusively methylated by PRMT9, and the pre-mRNA anchoring site, a cis-regulatory element that is critical for RNA splicing. Additionally, using human and mouse cell lines, as well as an SF3B2 arginine methylation-deficient mouse model, we provide strong evidence that SF3B2 is the primary methylation substrate of PRMT9, thus highlighting the conserved function of the PRMT9/SF3B2 axis in regulating pre-mRNA splicing.