bluuebunny/crossref_metadata_2025 huggingface dataset:
Biogenic silver-doped mesoporous silica nanoparticles for multifunctional eco-designed textile printing
Authors: Adel Abeer M. , El-Shall Fatma N. , Diab Mohamed A. , Al-Shemy Mona T.
Published: December 2022

The current study concerns the valorization of waste rice hulls into value-added materials. To achieve this goal, first, the extraction route of mesoporous silica nanoparticles (SiO2NPs) from rice hulls using citric acid as a carbon template was compared with that prepared by conventional methods of incineration only. Both routes were performed at different temperatures of 600 and 700°C, and the fabricated SiO2NPs were studied by N2 physisorption isotherm, X-ray diffraction (XRD), Fourier transform infrared (FTIR), dynamic light scattering (DLS), and thermogravimetric (TG) analyses. The results show the influence of both routes and temperature on the porous structure, surface area, and charge of as-fabricated SiO2NPs. Furthermore, the physico-chemical features of as-prepared mesoporous SiO2NPs were utilized, in a facile and green way, to prepare silver NPs with high anti-microbial activity. The results were validated by the tools of UV-visible, FTIR, XRD, and XPS spectroscopy. Finally, the fabricated silver-doped mesoporous SiO2NPs were used as auxiliary additives through one-pot printing of different types of fabric (i.e., polyester (synthetic fabric), cotton (natural fabric), and cotton/polyester (blended fabric)). The EDX mapping of the pigment-printed fabrics with Ag-doped SiO2NPs exhibited the homogeneous distribution of Ag and Si atoms together with C and O throughout the fabric matrix. Interestingly, the pigment-printed fabrics with Ag-doped SiO2NPs demonstrated superior antibacterial activity, ultraviolet protection factor (UPF), and color characteristics in comparison to the conventional dyeing component.

Graphical Abstract
Clustering: an R library to facilitate the analysis and comparison of cluster algorithms
Authors: Martos Luis Alfonso Pérez , García-Vico Ángel Miguel , González Pedro , Carmona Cristóbal J.
Published: December 2022

Clustering is an unsupervised learning method that divides data into groups of similar features. Researchers use this technique to categorise and automatically classify unlabelled data to reveal data concentrations. Although there are other implementations of clustering algorithms in R, this paper introduces the Clustering library for R, aimed at facilitating the analysis and comparison between clustering algorithms. Specifically, the library uses relevant clustering algorithms from the literature with two objectives: firstly to group data homogeneously by establishing differences between clusters and secondly to generate a ranking between the algorithms and the attributes of a data set to obtain the optimal number of clusters. Finally, it is crucial to highlight the added value that the library provides through its interactive graphical user interface, where experiments can be easily configured and executed without requiring expert knowledge of the parameters of each algorithm.
Ultrasound in the diagnosis and differential diagnosis of enoral and plunging ranula: a detailed and comparative analysis
Authors: Koch Michael , Mantsopoulos Konstantinos , Leibl Victoria , Müller Sarina , Iro Heinrich , Sievert Matti
Published: December 2022

Purpose

To develop sonographic criteria for ranula that to allow rapid and precise diagnosis, differentiation between enoral (ER) and plunging ranula (PR), and differential diagnosis from other competing pathologies in this region.

Methods

Patients who presented with or were referred with ranula between 2002 and 2022 were assessed in a retrospective study. After clinical investigation, ultrasound examinations were performed in all cases. Several sonographic parameters describing the echotexture, shape and size of ranulas, their relationship to important surrounding anatomical landmarks and the characteristic spreading pattern of ERs and PRs were elaborated and evaluated.

Results

207 ranulas were included (82.12% ERs and 17.87% PRs). The ranulas were all in close anatomical relationship to the sublingual gland (SLG) and mylohyoid muscle (MM). The echo texture was hypoechoic to anechoic in 97.6% of the lesions. In comparison with ERs, PRs were larger and irregular in shape significantly more often (P = 0.0001). There were significant differences between ERs and PRs in their exact location relative to the SLG (superficial, deep, anterior, eachP = 0.0001; posterior,P = 0.03) and level of the MM (above, below, above and below,P = 0.0001 each). The exact extent and plunging pattern were depicted in all PRs, but naturally in none of the ERs.

Conclusions

The ultrasound criteria developed in this study, confirming previously published results, indicate that ultrasound is an excellent diagnostic tool for diagnosing ranula and differentiating between ERs and PRs.
The Utility of Machine Learning Models for Predicting Chemical Contaminants in Drinking Water: Promise, Challenges, and Opportunities
Authors: Hu Xindi C. , Dai Mona , Sun Jennifer M. , Sunderland Elsie M.
Published: December 2022

Purpose of Review

This review aims to better understand the utility of machine learning algorithms for predicting spatial patterns of contaminants in the United States (U.S.) drinking water.

Recent Findings

We found 27 U.S. drinking water studies in the past ten years that used machine learning algorithms to predict water quality. Most studies (42%) developed random forest classification models for groundwater. Continuous models show low predictive power, suggesting that larger datasets and additional predictors are needed. Categorical/classification models for arsenic and nitrate that predict exceedances of pollution thresholds are most common in the literature because of good national scale data coverage and priority as environmental health concerns. Most groundwater data used to develop models were obtained from the United States Geological Survey (USGS) National Water Information System (NWIS). Predictors were similar across contaminants but challenges are posed by the lack of a standard methodology for imputation, pre-processing, and differing availability of data across regions.

We reviewed 27 articles that focused on seven drinking water contaminants. Good performance metrics were reported for binary models that classified chemical concentrations above a threshold value by finding significant predictors. Classification models are especially useful for assisting in the design of sampling efforts by identifying high-risk areas. Only a few studies have developed continuous models and obtaining good predictive performance for such models is still challenging. Improving continuous models is important for potential future use in epidemiological studies to supplement data gaps in exposure assessments for drinking water contaminants. While significant progress has been made over the past decade, methodological advances are still needed for selecting appropriate model performance metrics and accounting for spatial autocorrelations in data. Finally, improved infrastructure for code and data sharing would spearhead more rapid advances in machine-learning models for drinking water quality.
Spatial estimation of groundwater quality, hydrogeochemical investigation, and health impacts of shallow groundwater in Kabul city, Afghanistan
Authors: Hamidi Mohammad Daud , Kissane Stephen , Bogush Anna A. , Karim Abdul Qayeum , Sagintayev Janay , Towers Sam , Greenwell Hugh Christopher
Published: December 2022

The management of groundwater in densely populated areas with no centralized water treatment is critical for the prevention of diseases and maintaining sanitation. Here, we determine the bacteriological and chemical characteristics of groundwater in Kabul city, a resource that 4.1 million individuals rely on. Groundwater samples were analyzed from 41 newly established piezometric wells across Kabul, and data were compared with the last detailed study, undertaken in 2007, to understand contamination trends in an area that has undergone significant development and social changes. Piper diagrams, Gibbs diagrams, correlation analysis, and bivariate plots examine the hydrogeochemical and natural occurring processes of groundwater. The average concentration of cations followed the order Na+  > Mg2+  > Ca2+  > K+, and anions HCO3− > NO3− > Cl− > SO42− > F with Gibbs diagrams indicating mainly rock-weathering influence groundwater chemistry. An increase in nitrate (NO3−) and E. coli indicates anthropogenic activities impacting the shallow groundwater quality, with significantly elevated nitrate (over 50 mg/L) and E. coli (up to 250 CFU/100 mL). The increasing presence of E. coli and NO3− in the shallow groundwater of Kabul city in turn suggests problematic links to the prevalence of waterborne diseases. Additionally, the water quality index (WQI) was used to assess groundwater quality, and rank its suitability for drinking purposes. The WQI analysis showed that less than 35% of shallow groundwater samples had good water quality. The findings of this study are crucial for the development and sustainable management of groundwater in the city. In short term, we propose interventions such as point-of-use (POU) water purification which may offer temporary respite for waterborne disease prevention. Kabul city requires immediate attention to developing sustainable groundwater management policies, expansion of the water supply network, groundwater quality monitoring, and wastewater management.
Bioinspired Materials: From Distinct Dimensional Architecture to Thermal Regulation Properties
Authors: Ling Xin , Osotsi Maurice I. , Zhang Wang , Wu Yu , Jin Qingjun , Zhang Di
Published: December 2022

The structural evolutions of the organisms during the development of billions of years endow them with remarkable thermal-regulation properties, which have significance to their survival against the outer versatile environment. Inspired by the nature, there have been extensive researches to develop thermoregulating materials by mimicking and utilizing the advantages from the natural organisms. In this review, the latest advances in thermal regulation of bioinspired microstructures are summarized, classifying the researches from dimension. The representative materials are described with emphasis on the relationship between the structural features and the corresponding thermal-regulation functions. For one-dimensional materials, wild silkworm cocoon fibers have been involved, and the reasons for unique optical phenomena have been discussed. Pyramid cone structure, grating and multilayer film structure are chosen as typical examples of two-dimensional bionics. The excellent thermal performance of the three-dimensional network frame structures is the focus. Finally, a summary and outlook are given.
Enhanced corrosion resistance of epoxy-films on ultra-thin SiOx PECVD film coated laser surface melted Al-alloys
Authors: Varghese J. , Vieth P. , Xie X. , Grundmeier G.
Published: December 2022

The influence of ultra-thin SiOx plasma deposited films on the corrosion resistance of adhesive films on a laser surface melted 7075 aluminium alloy was investigated by means of complementary techniques in comparison to the just laser surface melted state. Laser surface melting (LSM) was performed using a continuous wave mode at a wavelength of 1064 nm. Ultra-thin plasma polymer films were deposited from a mixture of hexamethyldisilane (HMDSO), oxygen, and argon by means of an audio-frequency glow discharge. The surface morphology and surface chemistry compositions were investigated by employing field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX), diffuse reflection infrared Fourier transform spectroscopy, and X-ray photoelectron spectroscopy. The corrosion resistance of plasma polymer coated LSM Al-7075 alloy was studied using linear sweep voltammetry and electrochemical impedance spectroscopy in a chloride-containing electrolyte. The electrochemical studies showed an improved corrosion resistance for plasma film-coated alloys compared to the just laser surface melted state. To study the corresponding surface adhesive properties, the samples were coated with an epoxy amine adhesive. 90°-peel test under humid conditions confirmed the improvement of interfacial wet-adhesion corrosion tests showed a strong improvement of the delamination resistance of adhesives caused by the ultra-thin interfacial SiOx-films.
Exploring the Concept of Solidarity in the Context of AI: An Ethics in Design Approach
Authors: Rudschies Catharina
Published: December 2022

AI ethics guidelines have proposed the principle of solidarity as an important principle for Ethics in Artificial Intellligence (AI). However, they often leave out explanations on how solidarity ought to be understood and put into practice in the context of ethical AI. This paper explores the principle of solidarity in the context of AI. It examines solidarity from an Ethics in Design perspective, meaning how solidarity could be accounted for in the processes of technological design. Since solidarity conceptualisations differ depending on the respective discipline they are applied in, this paper first attempts to disentangle the many conceptual understandings and proposes a more discipline-neutral solidarity account describing solidarity’s core on the basis of five elements: (1) an element of relationality based on (2) a connecting element that builds the grounds for the relationship, (3) a cognitive element of awareness and recognition, (4) a motivational source, and (5) an element of duty. By using this account to explore solidarity in an AI context, it will be shown that approaching solidarity with an Ethics in Design perspective has its challenges. Therefore, it is proposed that solidarity should be conceived of not as an ideal end state but as a perspective or lens that can guide design choices. Ethics in Design methods such as user-centric or participatory design are discussed as potential enablers for adopting such a solidarity perspective. Lastly, the paper addresses some challenges and limitations and argues that an approach to solidarity in Ethics in Design needs to be complemented with collective decision-making at the societal level, which is a political task.
Imagining Ecuador
Authors: Medina Cordova Luis A.
Published: December 2022

How are contemporary authors reimagining the idea of 'Ecuador' following the worst financial crisis in the nation's history, and how do countries on the periphery of the global literary market challenge and enrich World Literature?
Reimagining the Gendered Nation
Authors: Kenny Christina
Published: December 2022

Explores the complex and intersecting dimensions of gender, ethnicity, and culture on women in the Global South, as well as the central roles of women in resisting colonial rule, and their foundational contributions to post-independence constitutional reform and nation building.
Manufacturing in Colonial Zimbabwe, 1890-1979
Authors: Gwande Victor Muchineripi
Published: December 2022

A key book on Zimbabwe's industrial policy and the relationship between manufacturing, the state, and economic interest groups.
Conspiracy Culture in Stuart England
Authors: McKenzie Andrea
Published: December 2022

The death of Sir Edmund Berry Godfrey has baffled scholars and armchair detectives for centuries; this book offers compelling new evidence and, at last, a solution to the mystery.
Children's Rights and Food Marketing
Authors: Ó Cathaoir Katharina
Published: December 2022

This book provides a thorough account of states' obligations to prevent childhood obesity under the Convention on the Rights of the Child, focusing on restricting unhealthy food marketing to children. It argues that while political momentum is sluggish and stilted, children's rights provide a compelling basis for action. This is important because unhealthy food marketing is a transnational concern that no one state can effectively regulate alone.

Furthermore, the book fills gaps in research on socioeconomic rights by offering an analysis of states' obligations under the rights to health and nutrition in relation to non-communicable disease prevention in high-income states. The book avoids a myopic focus, examining state obligations in the context of conflicting and complementary international duties including international health law, the European Convention on Human Rights, European Union law and international trade law.

Children's Rights and Food Marketing focuses on the CRC as it binds all states parties to a basic framework, which, if fully implemented, provides children in developed and developing countries with entitlements to universal standards. Besides analysing state obligations, the book presents a blueprint for what a child rights approach to regulating unhealthy food marketing could look like. It focuses on the restriction of unhealthy food marketing in the European Union, spanning consumer protection, media law and data protection law. This book is of interest to academics, practitioners and organisations working in the field of public health law and children's rights.
Temporal Change of km‐Scale Underwater Sound Speed Structure and GNSS‐A Positioning Accuracy
Authors: Yokota Y. , Watanabe S. , Ishikawa T. , Nakamura Y.
Published: December 2022

Underwater disturbances are the largest error source in Global Navigation Satellite System ‐ Acoustic ranging combination technique (GNSS‐A) seafloor geodetic observation. In particular, the gradient of sound speed structure (SSS) directly affects the horizontal accuracy and needs to be examined. Previous studies have not investigated its temporal change component. In this paper, we verified the assumption that the underwater gradient structure does not change significantly during GNSS‐A observation for several hours through applying a modified version of an analysis software called GARPOS to actual data of SGO‐A (provided by Japan Coast Guard). Obtained results suggested that this assumption holds at many observation data, and the positioning accuracy becomes better. Some non‐improved observation epochs were speculated to be accompanied by structure changes for which this assumption was not valid. It is suggested that the SSS change during observation will be an important research topic in GNSS‐A.
Meteor Impact Could Inform Martian Mysteries
Authors: Hasler Caroline
Published: December 2022

The impact sent surface waves rippling over the Martian surface all the way to NASA’s InSight lander, giving scientists a rare view of the planet’s outer layer.
Solid Concentration as a Main Proxy for Basal Force Fluctuations Generated by Highly Concentrated Sediment Flows
Authors: Piantini M. , Gimbert F. , Korkolis E. , Rousseau R. , Bellot H. , Recking A.
Published: December 2022

Sediment flows generate ground vibrations by exerting force fluctuations on the riverbed. Linking force fluctuations to properties of highly concentrated sediment flows, however, remains particularly challenging due to complexities arising from grain‐to‐grain interactions. Here, we conduct downscaled flume experiments in which we specifically measure force fluctuations and local seismic vibrations together with flow properties of highly concentrated sediment flows at high spatial and temporal resolution. We observe hysteresis behaviors between force fluctuations amplitude and flow surface elevation and mass that occur during complex changes in internal flow dynamics. By contrast, force fluctuations amplitude exhibits a unique negative relationship with solid concentration. We suggest this is due to the rheology of dense granular flows, where solid concentration is a proxy for particle agitation. We therefore advance that solid concentration should be incorporated in seismic models of such sediment flows as a key parameter describing inter‐particle collisions and impacts to the bed.
Asymmetrically Stratified Beaufort Gyre: Mean State and Response to Decadal Forcing
Authors: Zhang Jiaxu , Cheng Wei , Steele Michael , Weijer Wilbert
Published: December 2022

Recent progress in understanding Beaufort Gyre (BG) dynamics reveals an important role of ice‐ocean stress in stabilizing BG freshwater content (FWC) over seasonal to interannual timescales. But how the BG's stratification and FWC respond to surface forcing over decadal timescales has not been fully explored. Using a global ocean‐sea ice model, we partition the BG into upper, middle (halocline), and lower (thermocline) layers and perform a volume budget analysis over 1948–2017. We find that the BG's asymmetric geometry (with steep and tight isohalines over continental slopes relative to the deep basin) is key in determining the mean volume transport balance. We further find that a net Ekman suction during 1983–1995 causes the upper and middle layers to deflate isopycnally, while an enhanced Ekman pumping during 1996–2017 causes these layers to inflate both isopycnally and diapycnally, the latter via anomalous flux from the upper to the middle layer.
On the Causes of Synoptic‐Scale Eddy Heat Flux Decline
Authors: Park Mingyu , Lee Sukyoung
Published: December 2022

The poleward heat flux by atmospheric waves plays a pivotal role in maintaining the meridional temperature gradient. A recent study found that in the Northern Hemisphere the heat flux by transient eddies has been weakening, and the study attributed this weakening to the smaller equator‐to‐pole temperature gradient caused by Arctic warming. During the period of 1979–2019 examined here, for the annual mean, both the synoptic‐scale eddy heat flux and the temperature gradient had indeed declined. However, from October to April, the synoptic‐scale eddy flux trend is more closely tied to the planetary‐scale eddy heat flux trend, than to the temperature gradient trend. From June to August, the synoptic‐scale eddy flux decline can be attributed to a warming of the high‐latitude land areas. Therefore, a more comprehensive interpretation of the synoptic‐scale eddy heat flux trend needs to include the dynamics of the planetary‐scale waves and summer land warming.
From Schrödinger to Von Kármán: An Intriguing New Geological Structure Revealed by the Chang'e‐4 Lunar Penetrating Radar
Authors: Cao Huaqing , Xu Yi , Xu Luyuan , Zhang Ling , Bugiolacchi Roberto , Zhang Feng
Published: December 2022

Since early 2019, the Lunar Penetrating Radar (LPR) onboard Chang'e‐4 (CE‐4)’s Yutu‐2 rover has been gathering data relating to the subsurface structure of the Von Kármán crater within the South Pole‐Aitken Basin (SPA) on the lunar farside. Low‐frequency radar data have the potential of carrying geological information of about 300 m worth of strata below the traversed path. Forty‐two days’ data have revealed a bifurcated structure within the layered structure beneath the CE‐4 surveying area for the first time, affecting the overlying reflectors between 90 and 310 m. This study suggests that, based on the morphological characteristics, thickness, depth (timing sequence) and direction of the newly found structure, its origin might be linked to the deposition of ejecta from the Schrödinger impact. The local stratigraphy is interpreted as consisting of distinct geological layers, corresponding to the superposition of ejecta from different impact craters, paleo‐regolith, and basaltic lava flows.
Interdecadal Pacific Oscillation in Northern Greenland Dust Concentration Variability During the Last 400 Years
Authors: Rimbu N. , Ionita M. , Lohmann G.
Published: December 2022

Statistical analysis of reanalysis and observed data reveals that high dust surface mass concentration in northern Greenland is associated with a Pacific Decadal Oscillation like pattern in its negative phase in the North Pacific as well as with La Niña conditions in the tropical Pacific region. The sea surface temperature anomalies in the Pacific realm resemble the Interdecadal Pacific Oscillation (IPO). The associated atmospheric circulation pattern, in the form of a wave‐train from the North Pacific to the Eurasian continent, favors enhanced dust uptake and transport toward the northern Greenland. Similar patterns are associated with a low‐resolution stacked record of five Ca2+ ice cores, that is, ngt03C93.2 (B16), ngt14C93.2 (B18), ngt27C94.2 (B21), GISP2−B, and NEEM‐2011‐S1, from northern Greenland, a proxy for regional dust concentration, during the last 400 years. We argue that northern Greenland ice core dust records could be used as proxies for the IPO and related teleconnections.
Structure Along the Martian Dichotomy Constrained by Rayleigh and Love Waves and Their Overtones
Authors: Kim D. , Stähler S. C. , Ceylan S. , Lekic V. , Maguire R. , Zenhäusern G. , Clinton J. , Giardini D. , Khan A. , Panning M. P. , Davis P. , Wieczorek M. , Schmerr N. , Lognonné P. , Banerdt W. B.
Published: December 2022

Using seismic recordings of event S1222a, we measure dispersion curves of Rayleigh and Love waves, including their first overtones, and invert these for shear velocity (VS) and radial anisotropic structure of the Martian crust. The crustal structure along the topographic dichotomy is characterized by a fairly uniform vertically polarized shear velocity (VSV) of 3.17 km/s between ∼5 and 30 km depth, compatible with the previous study by Kim et al. (2022), https://doi.org/10.1126/science.abq7157. Radial anisotropy as large as 12% (VSH > VSV) is required in the crust between 5 and 40 km depth. At greater depths, we observe a large discontinuity near 63 ± 10 km, below which VSV reaches 4.1 km/s. We interpret this velocity increase as the crust‐mantle boundary along the path. Combined gravimetric modeling suggests that the observed average crustal thickness favors the absence of large‐scale density differences across the topographic dichotomy.
Finding Magnetopause Standoff Distance Using a Soft X‐Ray Imager: 1. Magnetospheric Masking
Authors: Samsonov Andrey , Carter Jennifer Alyson , Read Andrew , Sembay Steven , Branduardi‐Raymont Graziella , Sibeck David , Escoubet Philippe
Published: December 2022

The magnetopause standoff distance characterizes global magnetospheric compression and deformation in response to changes in the solar wind dynamic pressure and interplanetary magnetic field orientation. We cannot derive this parameter from in situ spacecraft measurements. However, time series of the magnetopause standoff distance can be obtained in the near future using observations by soft X‐ray imagers. In two companion papers, we describe methods of finding the standoff distance from X‐ray images. In Part 1, we present the results of MHD simulations which we use for the calculation of the X‐ray emissivity in the magnetosheath and cusps. Some MHD models predict relatively high density in the magnetosphere, larger than observed in the data. Correcting this, we develop magnetospheric masking methods to separate the magnetosphere from the magnetosheath and cusps. We simulate the X‐ray emissivity in the magnetosheath for different solar wind conditions and dipole tilts.
First Observations of Equatorial Ionospheric Electric Fields Driven by Storm‐Time Rapidly Recurrent Magnetospheric Substorms
Authors: Fejer B. G. , Navarro L. A.
Published: December 2022

Geomagnetic storm ionospheric electrodynamics at the magnetic equator are examined in detail using upgraded, higher time resolution, Jicamarca incoherent scatter radar drift observations, SuperMAG geomagnetic field, and solar wind data to study equatorial ionospheric electric fields during the 8 September 2017 storm main and early recovery phases. We show that during a period of mostly large and southward Interplanetary Magnetic Field (IMF) Bz there were numerous daytime prompt penetration vertical and zonal plasma drifts. These prompt penetration events were closely associated with rapidly recurring (quasi‐periods ∼30 − 60 min) magnetospheric substorms with expansion phases corresponding to upward and westward drift (eastward and downward electric field) perturbations, and recovery phases to opposite polarity changes. The magnitudes of the zonal prompt penetration drifts were about twice larger than those of the vertical drifts. Our study suggests that magnetospheric substorms are the main drivers of prompt penetration electric fields during extended periods (over ∼2 hr) of nearly steady southward IMF Bz. We also find that in general substorms are major driving factors for disturbance electric fields during geomagnetic active times. Our data highlight the powerful capabilities of the Jicamarca incoherent scatter radar as a tool for detailed studies of short‐lived solar wind‐magnetosphere‐ionosphere coupling processes.
Dayside Upper‐Thermospheric Density Fluctuations as Observed by GRACE and GRACE‐FO at ∼500 km Height
Authors: Park Jaeheung , van den IJssel Jose , Siemes Christian
Published: December 2022

We statistically investigate fluctuation amplitudes (normalized to the background values) of dayside low‐/mid‐latitude upper‐thermospheric mass density as observed by the Gravity Recovery and Climate Experiment (GRACE) and GRACE‐Follow‐On (GRACE‐FO) spacecraft at ∼500 km altitude between 2002 and 2022. There are three new findings in our results. First, the climatology closely replicates previous studies on stratospheric and upper‐thermospheric gravity waves (GWs) below the GRACE(‐FO) altitudes. For example, in low‐latitude regions, the fluctuations are stronger above continents than in the oceanic area. Mid‐latitude fluctuations prefer the local winter hemisphere to the summer, and the South American/Atlantic region in June solstice hosts stronger fluctuations than in any other low‐/mid‐latitude locations or seasons. Fluctuations are more intense under lower solar activity. The above‐mentioned consistency of the GRACE(‐FO) results with previous lower‐altitude GW studies confirms that GWs can penetrate up to 500 km. Second, the anti‐correlation of upper‐thermospheric GW with solar activity, which has been earlier reported for multi‐year time scales, can also be identified on the scale of the solar rotation period (∼27 days). Third, we demonstrate asymmetry between pre‐noon and post‐noon GWs. The former exhibits stronger GW activity, which may result from the colder thermosphere being more favorable for intense mass density fluctuations via secondary/tertiary GW generation.
New Insights Into the Petrogenesis of Voluminous Crustal‐Signature Silicic Volcanic Rocks of the Toba Eruptions (Indonesia)
Authors: Liu Ping‐Ping , Chung Sun‐Lin , Chesner Craig A. , Gao Meng‐Hao , Lai Yu‐Ming , Lee Hao‐Yang , Yang Yue‐Heng
Published: December 2022

The formation of large‐volume silicic magmas in arc settings is fundamental for understanding trans‐crustal magmatic systems related to subduction zones. Here, we present an integrated study of the four Quaternary Toba eruptions and pre‐caldera Haranggaol Andesite on Sumatra, Indonesia. This rock suite has significantly enriched Sr‐Nd isotopes (87Sr/86Sr = 0.71220–0.71517, εNd = −8.9 to −10.6) compared with other volcanic rocks on Sunda‐Banda arc, but is similar to the post‐caldera (<74 ka) Sipisupisu basalts near the Toba Caldera. Thermodynamic modeling using Magma Chamber Simulator has revealed that the Toba silicic rocks can be produced by a two‐stage assimilation and fractional crystallization of mantle‐derived basaltic melts with compositions similar to the Sipisupisu basalts in the lower and upper crustal magma reservoirs. Binary modeling of Sr‐Nd isotopes suggests that the rocks near the Toba Caldera can be produced by mixing of 5%–10% of the subducting Nicobar Fan sediments (87Sr/86Sr = 0.73493, εNd = −14 on average) with depleted MORB mantle (DMM). Indeed, decompressional partial melting modeling of bulk mixtures of DMM with 7% subducting sediments using pMELTS indicates that the melts generated can have geochemical compositions similar to the Sipisupisu basalts. We therefore argue that hybridization of the subducting sediments with the mantle wedge could be an alternative scenario responsible for the enriched isotopic characteristics of the rocks near Toba. Prolonged fractionation of mantle‐derived enriched/depleted basaltic melts, accompanied by crustal assimilation and crystal‐melt segregation, could be common processes in generating large‐volume silicic magmas on continental arcs.
Influence of Frictional Melt on the Seismic Cycle: Insights From Experiments on Rock Analog Material
Authors: Conrad E. M. , Tisato N. , Carpenter B. M. , Di Toro G.
Published: December 2022

The formation of frictional melt likely impacts the coseismic and, when solidified (pseudotachylyte), the interseismic strength of faults. Here we investigate these effects through experiments using a new energy‐controlled rotary shear machine (ECoR) on simulated faults made of a transparent rock analog material (polymethyl‐methacrylate). As in nature, ECoR allows (a) elastic strain energy to accumulate at different loading rates and (b) the spontaneous nucleation of slip events. ECoR is equipped with a high‐speed camera, thermocouples, and transducers to monitor the surface, temperature, and acoustic emissions (AEs), respectively. We perform experiments at normal stresses of ∼3.5 MPa across loading rates from 0.15 MPa/s, phase A, to 2.5 MPa/s, phases B‐C‐D. In phase A, the temperature remains constant, and slip events occur without visible melting every 3.3–6.4 s with 0.5–0.7 MPa stress drops and 3–7 mm displacements. In phases B‐C, slip events occur in the presence of melts every 0.5–0.9 s, and the bulk temperature increases progressively. Melt solidification increases static friction yielding slip events with stress drops up to 5 MPa and displacements up to 3 cm. Samples produce high‐frequency AEs during slip acceleration and deceleration. Once the bulk temperature reaches ∼110°C, a “final” and silent long displacement event occurs in the presence of melts (phase D). Experimental observations suggest that melt formation modulates the coseismic (flash melting, melt lubrication, and viscous braking) and interseismic (welding) stages. Furthermore, AEs associated with coseismic fault weakening and strengthening may have their natural equivalent and could be observed in seismograms through near‐fault instrumentation.
Lightning Over Central Canada: Skill Assessment for Various Land‐Atmosphere Model Configurations and Lightning Indices Over a Boreal Study Area
Authors: Mortelmans Jonas , Bechtold Michel , Brisson Erwan , Lynn Barry , Kumar Sujay , De Lannoy Gabriëlle
Published: December 2022

Current lightning predictions are uncertain because they rely on empirical diagnostic relationships and often use coarse‐scale climate scenario simulations in which deep convection is parameterized. Previous studies demonstrated that simulations with convection‐permitting resolutions improve lightning predictions compared to coarser‐grid simulations using convection parameterizations for different geographical locations but not over the boreal zone. In this study, lightning simulations with the NASA Unified‐Weather Research and Forecasting model are evaluated over a domain including the Great Slave Lake in Canada, for six lightning seasons. The simulations are performed at convection‐parameterized (9 km) and convection‐permitting (3 km) resolution using the Goddard 4ICE and the Thompson microphysics schemes. Four lightning indices are evaluated against observations from the Canadian Lightning Detection Network, in terms of spatiotemporal frequency distribution, spatial pattern, daily climatology, and an event‐based overall skill assessment. The Thompson scheme is, regardless of the spatial resolution, superior to the Goddard 4ICE scheme in predicting daily climatology but worse in predicting the spatial patterns of lightning occurrence. Results indicate that lightning estimation benefits from modeling at convection‐permitting resolution, in particular for the ice‐based lightning indices. In contrast, the product of convective available potential energy and precipitation rate proved to be the most robust index that was largely invariant to varying spatial resolution. Finally, this study reveals issues of the models to reproduce the observed spatial pattern of lightning well, which might be related to an insufficient representation of land surface heterogeneity, including peatlands, in the study area.
Intermodel Spread in Walker Circulation Responses Linked to Spread in Moist Stability and Radiation Responses
Authors: Duffy Margaret L. , O’Gorman Paul A.
Published: December 2022

The response of the Pacific Walker circulation (WC) to long‐term warming remains uncertain. Here, we diagnose contributions to the WC response in comprehensive and idealized general circulation model (GCM) simulations. We find that the spread in WC response is substantial across both the Coupled Model Intercomparison Project (CMIP6) and the Atmospheric Model Intercomparison Project (AMIP) models, implicating differences in atmospheric models in the spread in projected WC strength. Using a moist static energy (MSE) budget, we evaluate the contributions to changes in the WC strength related to changes in gross moist stability (GMS), horizontal MSE advection, radiation, and surface fluxes. We find that the multimodel mean WC weakening is mostly related to changes in GMS and radiation. Furthermore, the spread in WC response is related to the spread in GMS and radiation responses. The GMS response is potentially sensitive to parameterized convective entrainment which can affect lapse rates and the depth of convection. We thus investigate the role of entrainment in setting the GMS response by varying the entrainment rate in an idealized GCM. The idealized GCM is run with a simplified Betts‐Miller convection scheme, modified to represent entrainment. The weakening of the WC with warming in the idealized GCM is dampened when higher entrainment rates are used. However, the spread in GMS responses due to differing entrainment rates is much smaller than the spread in GMS responses across CMIP6 models. Therefore, further work is needed to understand the large spread in GMS responses across CMIP6 and AMIP models.
Using Neural Networks to Predict Hurricane Storm Surge and to Assess the Sensitivity of Surge to Storm Characteristics
Authors: Lockwood Joseph W. , Lin Ning , Oppenheimer Michael , Lai Ching‐Yao
Published: December 2022

Hurricane storm surge represents a significant threat to coastal communities around the world. Here, we use artificial neural network (ANN) models to predict storm surge levels using hurricane characteristics along the US Gulf and East Coasts. The ANN models are trained with storm surge levels from a hydrodynamic model and physical characteristics of synthetic hurricanes which are downscaled from National Centers for Environmental Prediction (NCEP) reanalysis using a statistical‐deterministic hurricane model. The ANN models are able to accurately predict storm surge levels with root‐mean‐square errors (RMSE) below 0.2 m and correlation coefficients > 0.85. The ANN models trained with the NCEP data also show satisfactory accuracy (RMSE below 0.7 m; correlation > 0.7) in predicting storm surge levels for hurricanes downscaled from future climate projections. Once trained, we use the ANN models to assess the sensitivity of storm surge levels to variations in hurricane characteristics and local geophysical features. Progressively stronger maximum wind speeds and larger outer radius sizes independently increase storm surge levels at all locations along the US East and Gulf Coasts. The response of storm surge levels to changes in hurricane translation speed, however, is found to be sensitive to coastal configuration, with increases in hurricane translation speed amplifying (reducing) storm surge levels in open ocean (semi‐enclosed) regions.
Vascular phenotypes in early hypertension
Authors: Murray Eleanor C. , Delles Christian , Orzechowski Patryk , Renc Pawel , Sitek Arkadiusz , Wagenaar Joost , Guzik Tomasz J.
Published: December 2022

The study characterises vascular phenotypes of hypertensive patients utilising machine learning approaches. Newly diagnosed and treatment-naïve primary hypertensive patients without co-morbidities (aged 18–55, n = 73), and matched normotensive controls (n = 79) were recruited (NCT04015635). Blood pressure (BP) and BP variability were determined using 24 h ambulatory monitoring. Vascular phenotyping included SphygmoCor® measurement of pulse wave velocity (PWV), pulse wave analysis-derived augmentation index (PWA-AIx), and central BP; EndoPAT™-2000® provided reactive hyperaemia index (LnRHI) and augmentation index adjusted to heart rate of 75bpm. Ultrasound was used to analyse flow mediated dilatation and carotid intima-media thickness (CIMT). In addition to standard statistical methods to compare normotensive and hypertensive groups, machine learning techniques including biclustering explored hypertensive phenotypic subgroups. We report that arterial stiffness (PWV, PWA-AIx, EndoPAT-2000-derived AI@75) and central pressures were greater in incident hypertension than normotension. Endothelial function, percent nocturnal dip, and CIMT did not differ between groups. The vascular phenotype of white-coat hypertension imitated sustained hypertension with elevated arterial stiffness and central pressure; masked hypertension demonstrating values similar to normotension. Machine learning revealed three distinct hypertension clusters, representing ‘arterially stiffened’, ‘vaso-protected’, and ‘non-dipper’ patients. Key clustering features were nocturnal- and central-BP, percent dipping, and arterial stiffness measures. We conclude that untreated patients with primary hypertension demonstrate early arterial stiffening rather than endothelial dysfunction or CIMT alterations. Phenotypic heterogeneity in nocturnal and central BP, percent dipping, and arterial stiffness observed early in the course of disease may have implications for risk stratification.
Cave Thiovulum (Candidatus Thiovulum stygium) differs metabolically and genomically from marine species
Authors: Bizic Mina , Brad Traian , Ionescu Danny , Barbu-Tudoran Lucian , Zoccarato Luca , Aerts Joost W , Contarini Paul-Emile , Gros Olivier , Volland Jean-Marie , Popa Radu , Ody Jessica , Vellone Daniel , Flot Jean-François , Tighe Scott , Sarbu Serban M
Published: December 2022

Thiovulum spp. (Campylobacterota) are large sulfur bacteria that form veil-like structures in aquatic environments. The sulfidic Movile Cave (Romania), sealed from the atmosphere for ~5 million years, has several aqueous chambers, some with low atmospheric O2 (~7%). The cave’s surface-water microbial community is dominated by bacteria we identified as Thiovulum. We show that this strain, and others from subsurface environments, are phylogenetically distinct from marine Thiovulum. We assembled a closed genome of the Movile strain and confirmed its metabolism using RNAseq. We compared the genome of this strain and one we assembled from public data from the sulfidic Frasassi caves to four marine genomes, including Candidatus Thiovulum karukerense and Ca. T. imperiosus, whose genomes we sequenced. Despite great spatial and temporal separation, the genomes of the Movile and Frasassi Thiovulum were highly similar, differing greatly from the very diverse marine strains. We concluded that cave Thiovulum represent a new species, named here Candidatus Thiovulum stygium. Based on their genomes, cave Thiovulum can switch between aerobic and anaerobic sulfide oxidation using O2 and NO3- as electron acceptors, the latter likely via dissimilatory nitrate reduction to ammonia. Thus, Thiovulum is likely important to both S and N cycles in sulfidic caves. Electron microscopy analysis suggests that at least some of the short peritrichous structures typical of Thiovulum are type IV pili, for which genes were found in all strains. These pili may play a role in veil formation, by connecting adjacent cells, and in the motility of these exceptionally fast swimmers.
Effect of methylphenidate on functional controllability: a preliminary study in medication-naïve children with ADHD
Authors: Henry Teague R. , Fogleman Nicholas D. , Nugiel Tehila , Cohen Jessica R.
Published: December 2022

Methylphenidate (MPH) is the recommended first-line treatment for attention-deficit/hyperactivity disorder (ADHD). While MPH’s mechanism of action as a dopamine and noradrenaline transporter blocker is well known, how this translates to ADHD-related symptom mitigation is still unclear. As functional connectivity is reliably altered in ADHD, with recent literature indicating dysfunctional connectivity dynamics as well, one possible mechanism is through altering brain network dynamics. In a double-blind, placebo-controlled MPH crossover trial, 19 medication-naïve children with ADHD underwent two functional MRI scanning sessions (one on MPH and one on placebo) that included a resting state scan and two inhibitory control tasks; 27 typically developing (TD) children completed the same protocol without medication. Network control theory, which quantifies how brain activity reacts to system inputs based on underlying connectivity, was used to assess differences in average and modal functional controllability during rest and both tasks between TD children and children with ADHD (on and off MPH) and between children with ADHD on and off MPH. Children with ADHD on placebo exhibited higher average controllability and lower modal controllability of attention, reward, and somatomotor networks than TD children. Children with ADHD on MPH were statistically indistinguishable from TD children on almost all controllability metrics. These findings suggest that MPH may stabilize functional network dynamics in children with ADHD, both reducing reactivity of brain organization and making it easier to achieve brain states necessary for cognitively demanding tasks.
Rise and fall of sea ice production in the Arctic Ocean’s ice factories
Authors: Cornish S. B. , Johnson H. L. , Mallett R. D. C. , Dörr J. , Kostov Y. , Richards A. E.
Published: December 2022

The volume, extent and age of Arctic sea ice is in decline, yet winter sea ice production appears to have been increasing, despite Arctic warming being most intense during winter. Previous work suggests that further warming will at some point lead to a decline in ice production, however a consistent explanation of both rise and fall is hitherto missing. Here, we investigate these driving factors through a simple linear model for ice production. We focus on the Kara and Laptev seas-sometimes referred to as Arctic “ice factories” for their outsized role in ice production, and train the model on internal variability across the Community Earth System Model’s Large Ensemble (CESM-LE). The linear model is highly skilful at explaining internal variability and can also explain the forced rise-then-fall of ice production, providing insight into the competing drivers of change. We apply our linear model to the same climate variables from observation-based data; the resulting estimate of ice production over recent decades suggests that, just as in CESM-LE, we are currently passing the peak of ice production in the Kara and Laptev seas.
Spin-decoupling of vertical cavity surface-emitting lasers with complete phase modulation using on-chip integrated Jones matrix metasurfaces
Authors: Ni Pei-Nan , Fu Pan , Chen Pei-Pei , Xu Chen , Xie Yi-Yang , Genevet Patrice
Published: December 2022

Polarization response of artificially structured nano-antennas can be exploited to design innovative optical components, also dubbed “vectorial metasurfaces”, for the modulation of phase, amplitude, and polarization with subwavelength spatial resolution. Recent efforts in conceiving Jones matrix formalism led to the advancement of vectorial metasurfaces to independently manipulate any arbitrary phase function of orthogonal polarization states. Here, we are taking advantages of this formalism to design and experimentally validate the performance of CMOS compatible Jones matrix metasurfaces monolithically integrated with standard VCSELs for on-chip spin-decoupling and phase shaping. Our approach enables accessing the optical spin states of VCSELs in an ultra-compact way with previously unattainable phase controllability. By exploiting spin states as a new degree of freedom for laser wavefront engineering, our platform is capable of operating and reading-out the spin-momentum of lasers associated with injected spin carriers, which would potentially play a pivotal role for the development of emerging spin-optoelectronic devices.