bluuebunny/crossref_metadata_2025 huggingface dataset:
Optogenetic tools controlled by ultraviolet-B light
Authors: Ouyang Xinhao , Ren Hui , Huang Xi
Published: May 2021

Decades of genetic, molecular and biochemical studies in plants have provided foundational knowledge about light sensory proteins and led to their application in synthetic biology. Optogenetic tools take advantage of the light switchable activity of plant photoreceptors to control intracellular signaling pathways. The recent discovery of the UV-B photoreceptor UV RESISTANCE LOCUS 8 in the model plant Arabidopsis thaliana opens up new avenues for light-controllable methodologies. In this review, we discuss current developments in optogenetic control by UV-B light and its signaling components, as well as rational considerations in the design and applications of UV-B-based optogenetic tools.
Silicon carbide nanocomposites reinforced with disordered graphitic carbon formed in situ through oxidation of Ti3C2 MXene during sintering
Authors: Petrus M. , Woźniak J. , Cygan T. , Lachowski A. , Rozmysłowska-Wojciechowska A. , Wojciechowski T. , Ziemkowska W. , Chlubny L. , Jastrzębska A. , Adamczyk-Cieślak B. , Olszyna A.
Published: May 2021

This article describes the manufacturing of silicon carbide composites with the addition of quasi-two-dimensional titanium carbide Ti3C2, known as MXene. The composites were obtained by the powder metallurgy technique, consolidated with the use of the Spark Plasma Sintering method at 1900 °C and dwelled for 30 min. The influence of the Ti3C2 MXene addition on the microstructure and mechanical properties of the composites was investigated. The structure of the MXene phase after the sintering process was also analyzed. The results showed a significant increase (almost 50%) of fracture toughness for composites with the addition of 0.2 wt% Ti3C2 MXene. In turn, the highest hardness, 23.2 GPa, was noted for the composite with the addition of the 1.5 wt% Ti3C2 MXene phase. This was an increase of over 10% in comparison to the reference sample. The analysis of chemical composition and observations using a transmission electron microscope showed that the Ti3C2 MXene phase oxidizes during sintering, resulting in the formation of crystalline, highly defected, disordered graphite structures. The presence of these structures in the microstructure, similarly to graphene, significantly affects the hardness and fracture toughness of silicon carbide.
Changes in psychological distress after first vaginal intercourse in late adolescence
Authors: Vasilenko Sara A. , Lefkowitz Eva S. , Maggs Jennifer L.
Published: May 2021

Introduction

Although early sexual intercourse may be associated with increased depressive symptoms, little research has examined whether first intercourse in late adolescence is associated with changes in mental health.

Methods

This paper uses 3 years of longitudinal data from previously sexually abstinent late adolescent students at a large state university in the northeastern United States (N = 144, 53.5% male, M age = 18.5 years old, 47.2% White, 26.4% Asian/Hawaiian/Pacific Islander, 20.1% Hispanic/Latino, 18.1% Black/African American) to examine whether levels of psychological distress changed after first intercourse.

Results

Students’ distress decreased after first intercourse, although this effect was only significant two or more semesters after first intercourse. There were no gender differences in these associations.

Conclusions

Findings suggest first intercourse was, on average, associated with decreased psychological distress for both male and female late adolescents.
E. coli versus Non-E. coli Urinary Tract Infections in Children
Authors: Al Nafeesah Abdullah , Al Fakeeh Khaled , Chishti Syed , Hameed Tahir
Published: May 2021

Background:

While Escherichia coli (E. coli) is the most common uropathogen implicated in urinary tract infections (UTIs) in children, some studies have found that there are different characteristics between different uropathogens in children. The aim of this study was to compare E. coli and non-E. coli UTIs in children with respect to their demographic data, predisposing factors, and imaging results.

Methodology:

A retrospective chart review was done in children during their first admission with urine culture confirmed UTI in a tertiary care center. We divided patients into E. coli and non-E. coli groups according to urine culture results.

Results:

Out of 202 children with their first admission for a culture-proven UTI, pathogens other than E. coli accounted for 24.3% of UTIs. Klebsiella pneumoniae was the most common non-E. coli pathogen, followed by Pseudomonas aeruginosa and Enterococcus species. Non-E. coli UTIs were significantly more common in male subjects, younger children, and children with a past history of UTI or who had received antibiotics prior to admission. In addition, higher rates of abnormalities on renal ultrasound and VCUG were found with non-E. coli organisms.

Conclusion:

There is a significant difference in demographic and imaging findings in children with non-E. coli UTIs. These findings may impact the work-up and treatment of UTIs in the pediatric population.
The Cult of St Edmund in Medieval East Anglia
Authors: Pinner Rebecca
Published: May 2021

An investigation of the growth and influence of the cult of St Edmund, and how it manifested itself in medieval material culture.
Erik Satie
Authors: Potter Caroline
Published: May 2021

Erik Satie's (1866-1925) music appeals to wide audiences and has influenced both experimental artists and pop musicians. Little about Satie was conventional, and he resists classification under easy headings such as 'classical music'. Instead of pursuing the path of a professional composer, Satie initially earned a living as a caf� pianist and moved in bohemian circles which prized satire, popularculture and experiment. Small wonder that his music is fundamentally new in conception. It is music which is not always designed to be listened to attentively: music which can be machine-like but isto be played by humans. For Satie, music was part of a wider concept of artistic creation, as evidenced by his collaborations with leading avant-garde artists and in works which cross traditional genre boundaries such as his texted piano pieces. His music was created in some of the most exciting and creatively stimulating environments of the late nineteenth and early twentieth century: Montmartreand Montparnasse. Paris was the artistic centre of Europe, and Satie was a notorious figure whose music and ideas are inextricably linked with the City of Light. This book situates Satie's work withinthe context and sonic environment of contemporary Paris. It shows that the influence of street music, musicians and poets interested in new technology, contemporary innovations and radical politics are all crucial to an understanding of Satie. Music from the ever-popular Gymnopédies to newly discovered works are discussed, and an online supplement features rare pieces recorded especially for the book. CAROLINE POTTER is Reader in Music at Kingston University London. A graduate in both French and Music, she has published widely on French music since Debussy and was Series Advisor to the Philharmonia Orchestra's Paris 2014-15 season.
Fit to Practice
Authors: Haynes Douglas M.
Published: May 2021

Traces the history of the British General Medical Council to reveal the persistence of hierarchies of gender, national identity, and race in determining who was fit to practice British medicine.
The Universe Behind Barbed Wire
Authors: Marynovych Myroslav
Published: May 2021

Ukrainian dissident Myroslav Marynovych recounts his involvement in the Brezhnev-era human rights movement in the Soviet Union and his resulting years as a political prisoner in Siberia and in internal exile.
La justice et la non-représentation au carrefour de la localisation sociale
Authors: Bernheim Emmanuelle , Noreau Pierre , Bahary-Dionne Alexandra
Published: May 2021

La présence accrue de justiciables non représenté·e·s devant les tribunaux est régulièrement attribuée à un manque de confiance envers le système judiciaire, notamment à l’égard des avocat·e·s. Agir seul·e devant les tribunaux serait donc un choix délibéré. Un sondage réalisé dans la population générale au Québec permet de démontrer au contraire que la grande majorité des citoyen·ne·s redoutent de faire face seul·e·s à la justice et souhaitent avoir accès aux services d’un·e professionnel·le du droit pour les représenter. Il permet aussi d’établir des liens entre certaines composantes de la localisation sociale des répondant·e·s – âge, condition socioéconomique, scolarité et genre – et leur opinion sur le système de justice et la non-représentation. Il faut en conclure que le rapport au droit et à la justice est la conséquence directe de structures sociales dont il faut tenir compte dans la compréhension de la réalité de la non-représentation.
ELLIPTIC CURVES AND -ADIC ELLIPTIC TRANSCENDENCE
Authors: PHAM DUC HIEP
Published: May 2021

We prove a necessary and sufficient condition for isogenous elliptic curves based on the algebraic dependence ofp-adic elliptic functions. As a consequence, we give a short proof of thep-adic analogue of Schneider’s theorem on the linear independence ofp-adic elliptic logarithms of algebraic points on two nonisogenous elliptic curves defined over the field of algebraic numbers.
Maternal perception, concern and dissatisfaction with child weight and their association with feeding practices in the Generation XXI birth cohort
Authors: Costa Alexandra , Hetherington Marion M. , Oliveira Andreia
Published: May 2021

What a mother thinks about her child’s weight status might influence what and how she feeds her child. We examined the association between maternal perception, concern and dissatisfaction with child weight alongside feeding practices. Participants were from the Generation XXI birth cohort (n= 3233). A validated version of the Child Feeding Questionnaire and the Overt/Covert Control scale were used. Associations were evaluated by linear regression models (βcoefficients and 95 % confidence intervals (95 % CI) with Bonferroni correction). Perceived underweight was associated with practices promoting food intake, such as higher pressure to eat at ages 4 and 7 years (β= 0·229; 95 % CI: 0·059, 0·398 andβ= 0·190; 95 % CI:0·005, 0·376, respectively) and lower restriction at age 4 (β= –0·175; 95 % CI: –0·0310, –0·039). At age 7, perceived overweight was associated with higher covert control (β= 0·203; 95 % CI: 0·029, 0·376). Mothers who were concerned about child weight reported higher restriction (β= 0·226; 95 % CI: 0·142, 0·310 at 4 years andβ= 0·261; 95 % CI: 0·169, 0·353 at 7 years) and covert control (β= 0·183; 95 % CI: 0·083, 0·282 at 4 years andβ= 0·171; 95 % CI: 0·073, 0·269 at 7 years). Maternal desire for a heavier child was associated with higher pressure to eat at both ages (β= 0·285; 95 % CI: 0·163, 0·406 andβ= 0·393; 95 % CI: 0·266, 0·520), while the desire for a thinner child was related to higher covert control at 7 years of age (β= 0·158; 95 % CI: 0·001, 0·316). Maternal perceptions and concern for child weight status are associated with feeding practices independently of actual weight status.
Calculating the linear critical gradient for the ion-temperature-gradient mode in magnetically confined plasmas
Authors: Roberg-Clark G.T. , Plunk G.G. , Xanthopoulos P.
Published: May 2021

A first-principles method to calculate the critical temperature gradient for the onset of the ion-temperature-gradient mode (ITG) in linear gyrokinetics is presented. We find that conventional notions of the connection length previously invoked in tokamak research should be revised and replaced by a generalized correlation length to explain this onset in stellarators. Simple numerical experiments and gyrokinetic theory show that localized ‘spikes’ in shear, a hallmark of stellarator geometry, are generally insufficient to constrain the parallel correlation length of the mode. ITG modes that localize within bad drift curvature wells that have a critical gradient set by peak drift curvature are also observed. A case study of near-helical stellarators of increasing field period demonstrates that the critical gradient can indeed be controlled by manipulating the magnetic geometry, but underscores the need for a general framework to evaluate the critical gradient. We conclude that average curvature and global shear set the correlation length of resonant ITG modes near the absolute critical gradient, the physics of which is included through direct solution of the gyrokinetic equation. Our method, which handles the general geometry and is more efficient than conventional gyrokinetic solvers, could be applied to future studies of stellarator ITG turbulence optimization.
Factors influencing the occurrence of negative interactions between people and crocodilians in Mexico
Authors: González-Desales Giovany Arturo , Sigler Luis , García-Grajales Jesús , Charruau Pierre , Zarco-González Martha Mariela , Balbuena-Serrano Ángel , Monroy-Vilchis Octavio
Published: May 2021

Negative interactions between people and crocodilians have increased worldwide, but in Mexico there have been few systematic reports and no rigorous evaluation of this problem. We compiled information on negative interactions between people and the spectacled caimanCaiman crocodilusand American crocodileCrocodylus acutusfrom the Worldwide Crocodilian Attack Database for 1993–2018, and we investigated interactions in greater depth, through interviews with people in La Encrucijada Biosphere Reserve. We examined the relationship between the occurrence of negative interactions between people andC. acutusand the species' nesting season and abundance, and presence records. In Mexico, the frequency of negative interactions increases when anthropogenic activities occur close to nesting sites (< 30 km) and during the nesting season (February–September). In La Encrucijada, following negative interactions with crocodiles, the local inhabitants killed 30 crocodiles measuring > 2.5 m long in 2011–2012. The frequency of negative human–crocodilian interactions was not correlated with the abundance of crocodilians but was correlated with the number of presence records of crocodiles. Strategies to minimize these interactions include warnings at nesting sites, increased monitoring of anthropogenic activities during the nesting season, and management of nests to prevent them being destroyed by people.
First step and last resort: One-Euro-Jobs after the reform
Authors: HARRER TAMARA , STOCKINGER BASTIAN
Published: May 2021

Job creation programmes aim at increasing the employability of hard-to-place unemployed, and eventually integrating them into employment. Yet, previous evaluation studies have been pessimistic about their efficacy. For One-Euro-Jobs, a job creation programme for welfare benefit recipients in Germany, previous evaluations found unfavourable effects particularly for easier-to-place participants. Thus, in 2012 the legislator reformed the programme in order to target the hard-to-place more accurately. This study is the first post-reform evaluation of One-Euro-Jobs. We find that, although the programme is indeed better targeted than before, One-Euro-Jobs decrease participants’ employment chances within three years after programme entry. These outcomes are worse than those found for pre-reform participants. We cannot conclude with certainty whether the reform decreased the programme’s efficacy, but we identify channels through which the reform and other contemporaneous changes may have done so. These channels include changes in programme design features, changes in business-cycle conditions, and prolonged lock-in effects due to “programme careers”. To substantiate the latter explanation, we also provide novel evidence that One-Euro-Jobs seem to initiate programme careers.
On the Banks of the Tiber: Opportunity and Transformation in Early Rome
Authors: Brock Andrea L. , Motta Laura , Terrenato Nicola
Published: May 2021

A geoarchaeological coring survey of the Forum Boarium has shed considerable light on Rome's archaic landscape. We present the first empirical evidence that substantiates ancient and modern assumptions about the existence of a river harbour and ford in early Rome. Prior to the growth of the city, the riverbank — reconstructed as a high ledge at the base of the Capitoline Hill and a low-lying shore north of the Aventine — was particularly advantageous for river-related activities. However, the river valley changed significantly in the sixth centuryb.c.e., as a result of complex fluvial processes that were arguably spurred by urbanisation. Around the beginning of the Republic, Rome's original harbour silted up, and a high, wide riverbank emerged in its place. The siltation continued until the Forum Boarium was urbanised in the mid-Republic. In order to build their city and maintain river harbour operations, the Romans therefore had to adapt to dynamic ecological conditions.
Colour and Directional Symbolism in Ancestral Pueblo Radial Offerings from Chaco Canyon
Authors: Mattson Hannah V.
Published: May 2021

Dedicatory offerings of small colourful objects are often found in pre-Hispanic architectural contexts in the Ancestral Pueblo region of the American Southwest. These deposits are particularly numerous in the roof support pillars of circular ritual structures (kivas) at the site of Pueblo Bonito, Chaco Canyon, which served as the ceremonial hub of the Chacoan regional system between the tenth and twelfth centuriesce. Based on the importance of directionality and colour in traditional Pueblo worldviews, archaeologists speculate that the contents of these radial offerings may likewise reference significant Chacoan cosmographic elements. In this paper, I explore this idea by examining the distribution of colours and materials in kiva pilaster repositories in relation to directional quadrants, prominent landscape features, and raw material sources. I discuss the results in the context of Pueblo cosmology and assemblage theory, arguing that particular colours were polyvalent and relational, deriving their meanings from their positions within interacting and heterogenous assemblages.
Takayasu’s arteritis presenting as acute myocardial infarction: case series and review of literature
Authors: Wilson Laura , Chandran Arun , Fudge James C. , Moguillansky Diego , Thatayatikom Akaluck , Philip Joseph , Jacobs Jeffrey P. , Bleiweis Mark , Elder Melissa , Gupta Dipankar
Published: May 2021

This series describes three adolescent females who presented with chest pain and ventricular dysfunction related to acute coronary ischemia secondary to Takayasu’s arteritis with varied courses of disease progression leading to a diverse range of therapies including cardiac transplantation. While Takayasu’s arteritis is rare in childhood, it should be strongly considered in any adolescent female presenting with systemic inflammation and chest pain consistent with myocardial infarction. A high index of suspicion can lead to early detection and aggressive management of the underlying vasculitis reducing associated morbidity and mortality. The purpose of this report is to describe the challenges in the clinical diagnosis and management of Takayasu’s arteritis with myocardial infarction. We also seek to enhance awareness about unique presentations of Takayasu’s arteritis within the paediatric community.
Lexicon or grammar? Using memory-based learning to investigate the syntactic relationship between Belgian and Netherlandic Dutch
Authors: De Troij Robbert , Grondelaers Stefan , Speelman Dirk , van den Bosch Antal
Published: May 2021

This article builds on computational tools to investigate the syntactic relationship between the highly related European national varieties of Dutch, viz. Belgian Dutch (BD) and Netherlandic Dutch (ND). It reports on a series of memory-based learning analyses of the post-verbal distribution ofer“there” in adjunct-initial existential constructions likeOp het dak staat (er) een schoorsteen“On the roof (there) is a chimney,’, which has been claimed to be among the most notoriously difficult variables in Dutch. On the basis of balanced datasets extracted from Flemish and Dutch newspaper corpora, it is shown thater’s distribution in both national varieties can be learned to a considerable extent from bare lexical input which is not assigned to higher-level categories. However, whereas this yields good results for ND, BD scores are consistently lower, suggesting that BD cannot do with lexical features alone to attain accuracy scores comparable to ND. This ties in with earlier findings that the more advanced standardization of ND materializes in a higher lexical collocability, whereas Flemish speakers need additional higher-level linguistic information to inserter.
Developing sugar-sweetened beverage warning labels for young adults
Authors: Falbe Jennifer , Montuclard Astrid , Engelman Alina , Adler Sabrina , Roesler Athena
Published: May 2021

Objective:

There is a lack of qualitative research developing sugar-sweetened beverage (SSB) warning labels with their intended end users. We sought to identify promising SSB warning elements for improving label effectiveness and for future testing in policy and institutional settings.

Design:

Mixed methods design using ten focus groups, a design task and a survey. The design task was used to generate ideas for an icon that would dissuade SSB consumption. The survey and focus group guide assessed participant perceptions of SSB warning label mock-ups of text (loss frame, gain frame and loss frame with attribution), colour and icon options.

Setting:

Three large public universities in California from February to March 2018.

Participants:

Young adult SSB consumers (n 86) enrolled in one of three diverse California public universities.

Results:

Participants perceived the following elements as most effective for reducing SSB consumption: loss-frame text with attribution to a credible source, yellow and red colour for label background and an image or icon to accompany the text. Preferred images included sugar near or inside of an SSB, intuitive shapes like a triangle with exclamation mark or octagon and a visual indicator of SSB sugar content compared with recommended limits. Support was high for using SSB warning labels in university cafeterias and on bottles/cans.

Conclusions:

Loss-frame text with a credible source, yellow or red label colour and icons could potentially enhance effectiveness of SSB warning labels and warrant further testing.
Aktueller Stellenwert der HDL-Cholesterin-Bestimmung für die kardiovaskuläre Risikoabschätzung
Authors: Wallimann-Annema Wijtske
Published: May 2021

Zusammenfassung. In der klinischen Praxis wird der High-Density-Lipoprotein-Cholesterin (HDL-C)-Wert häufig als Kriterium für die kardiovaskuläre Risikovorhersage herangezogen. HDL-Teilchen erfüllen zahlreiche Funktionen, die theoretisch vor Atherosklerose schützen. Dementsprechend haben umfangreiche Studien eindeutig gezeigt, dass ein tiefes HDL-C ein wichtiger unabhängiger Risikofaktor für kardiovaskuläre Erkrankungen ist. Jedoch gilt es mittlerweile als fraglich, ob sehr hohe HDL-C-Spiegel immer kardioprotektiv sind. Dies lässt sich durch die strukturelle Heterogenität der HDL-Partikel und den Verlust der Schutzfunktionen von HDL im Zusammenhang mit Krankheiten erklären, was mit der einfachen Messung von HDL-C nicht festgestellt werden kann. Neue Marker für die funktionelle Kapazität der HDL-Partikel werden in Zukunft das HDL-C als traditionellen Parameter für die kardiovaskuläre Risikoabschätzung möglicherweise ersetzen.
Das Long-COVID-Syndrom – ein neues Krankheitsbild nach COVID-19-Infekt
Authors: Funke-Chambour Manuela , Feldmeyer Laurence , Hoepner Robert , Huynh-Do Uyen , Maurer Britta , Rexhaj Emrush , Geiser Thomas
Published: May 2021

Zusammenfassung. Langzeitfolgen nach COVID-19 werden in der Literatur zunehmend berichtet. Noch Monate nach dem akuten Infekt leiden einige Betroffene an Atemnot, Müdigkeit und weiteren Beschwerden. Es wurden Einschränkungen der Lunge im Verlauf berichtet, aber auch Folgen am Immunsystem, am Herzen, am Nervensystem, an der Haut und den Nieren werden beschrieben oder vermutet. Diese Übersichtsarbeit soll den praktizierenden Ärzten und Ärztinnen einen kurzen Überblick über das aktuelle Verständnis des Long-COVID-Syndroms aus der Sicht von verschiedenen Fachexpertinnen und -experten geben. In Zukunft werden wir dieses neue Krankheitsbild besser verstehen und behandeln müssen.
Die Erfassung allgemeiner Wirkfaktoren in der Psychotherapie
Authors: Bräscher Anne-Kathrin , Witthöft Michael
Published: May 2021

Zusammenfassung: Theoretischer Hintergrund. Stundenbögen dienen einer standardisierten Prozessdiagnostik und Verlaufsdokumentation. Bislang vorliegende Instrumente werden in der Praxis häufig nicht eingesetzt, haben einen eingeschränkten Geltungsraum oder weisen psychometrische Schwächen auf. Der Mainzer Stundenbeurteilungsbogen (MSB) versucht allgemeine Wirkfaktoren ökonomisch zu erfassen. Ziel der Studie ist die Untersuchung des MSB in der Patienten- und Therapeutenversion hinsichtlich Faktorenstruktur, Itemstatistiken und Gütekriterien. Methoden: Der MSB wurde zu zwei Zeitpunkten (5. und 20. therapeutische Sitzung) in einer Stichprobe ambulanter Psychotherapiepatienten ( N = 4.608, N = 3.909) und deren Therapeuten ( N = 4.650 und N = 3.980 Bögen) untersucht. Die Faktorenstruktur wurde mittels explorativer und konfirmatorischer Faktorenanalysen untersucht und es wurden Reliabilitäts- und Validitätsanalysen vorgenommen. Ergebnisse: Ein Bifaktorenmodell mit drei Faktoren spiegelte weitgehend die theoretisch postulierte Struktur mit den Subskalen Therapiebeziehung, Problemaktualisierung und Problembewältigung wider, bei moderatem Modellfit. Maße der diskriminanten, konvergenten und prädiktiven Validität fielen zufriedenstellend aus. Diskussion: Der MSB ist ein reliables, valides und ökonomisches Instrument zu Erfassung der allgemeinen Wirkfaktoren Therapiebeziehung, Problembewältigung und Problemaktualisierung aus Patienten- und Therapeutensicht.
Assessing Reduced‐Dynamic Parametrizations for GRAIL Orbit Determination and the Recovery of Independent Lunar Gravity Field Solutions
Authors: Bertone S. , Arnold D. , Girardin V. , Lasser M. , Meyer U. , Jäggi A.
Published: May 2021

Orbit determination of probes visiting Solar System bodies is currently the main source of our knowledge about their internal structure, inferred from the estimate of their gravity field and rotational state. Nongravitational forces acting on the spacecraft need to be accurately included in the dynamical modeling (either explicitly or in the form of empirical parameters) not to degrade the solution and its geophysical interpretation. In this study, we present our recovery of NASA GRAIL orbits and our lunar gravity field solutions up to degree and order 350. We propose a systematic approach to select an optimal parametrization with empirical accelerations and pseudo‐stochastic pulses, by checking their impact against orbit overlaps or, in the case of GRAIL, the very precise inter‐satellite link. We discuss how parametrization choices may differ depending on whether the goal is limited to orbit reconstruction or if it also includes the solution of gravity field coefficients. We validate our setup for planetary geodesy by iterating extended lunar gravity field solutions from pre‐GRAIL gravity fields, and we discuss the impact of empirical parametrization on the interpretation of gravity solutions and of their error bars.
The Late Great Unconformity of the Central Canadian Shield
Authors: Sturrock C. P. , Flowers R. M. , Macdonald F. A.
Published: May 2021

The Great Unconformity is a widely distributed surface separating Precambrian rocks from overlying Phanerozoic sedimentary sequences. The causes and implications of this feature, and whether it represents a singular global event, are much debated. Here, we present new apatite (U‐Th)/He (AHe) thermochronologic data from the central Canadian Shield that constrain when the Precambrian basement last cooled to near‐surface temperatures, likely via exhumation, before deposition of overlying early Paleozoic sedimentary sequences that mark the Great Unconformity. AHe data from 11 samples (n = 57) across a broad region define a similar date‐eU pattern, implying a common thermal history. Higher eU (>25 ppm) apatite form distinct flat profiles of reproducible dates at ∼510 ± 49 Ma (mean and 1σstandard deviation), while lower eU (<25 ppm) apatite define a positive date‐eU trend with younger dates. The data patterns, geologic context, and thermal history modeling point toward >3 km of erosion across the entire ∼450,000 km2study area between 650 and 440 Ma, followed by modest reheating during later burial. Plume activity associated with intracratonic basin formation or continental rifting/breakup may have caused this erosion event. The post‐650 Ma timing of the last major sub‐Great Unconformity exhumation phase in this region implies a late Great Unconformity that is younger than inferred elsewhere in North America. This suggests that this feature is likely the result of multiple temporally distinct erosion events with differing footprints and mechanisms.
Stress Controls Rupture Extent and Maximum Magnitude of Induced Earthquakes
Authors: Kroll Kayla A. , Cochran Elizabeth S.
Published: May 2021

Seismic hazard forecasts of induced seismicity often require estimates of the maximum possible magnitude (Mmax). Empirical models suggest that maximum magnitudes, or expected number of earthquakes, are related to the volume of injected fluid. We perform a suite of 3D physics‐based earthquake simulations with rate‐ and state‐dependent friction, systematically varying the area of the pressurized region and the amplitude of the initial homogeneous or heterogeneous shear stress. Using the resulting catalog we explore the conditions that result in pressure‐controlled versus runaway ruptures that extend outside the pressurized zone. We find that proposed empirical scaling laws correctly predictMmaxwhen shear stresses are further from failure (≤90% of maximum shear stress) and for high amplitude stress fields. Runaway ruptures are observed for higher initial shear stresses and smoother stress fields. In these cases, runaway ruptures occur early after the onset of injection and rarely preceded by foreshock activity.
Impulsive Volcanic Plumes Generate Volcanic Lightning and Vent Discharges: A Statistical Analysis of Sakurajima Volcano in 2015
Authors: Smith Cassandra M. , Gaudin Damien , Van Eaton Alexa R. , Behnke Sonja A. , Reader Steven , Thomas Ronald J. , Edens Harald , McNutt Stephen R. , Cimarelli Corrado
Published: May 2021

The origin of electrical activity accompanying volcanic ash plumes is an area of heightened interest in volcanology. However, it is unclear how intense an eruption needs to be to produce lightning flashes as opposed to “vent discharges,” which represent the smallest scale of electrical activity. This study targets 97 carefully monitored plumes <3 km high from Sakurajima volcano in Japan, from June 1 to 7, 2015. We use multiparametric measurements from sensors including a nine‐station lightning mapping array and an infrared camera to characterize plume ascent. Findings demonstrate that the impulsive, high velocity plumes (>55 m/s) were most likely to create vent discharges, whereas lightning flashes occurred in plumes with high volume flux. We identified conditions where volcanic lightning occurred without detectable vent discharges, highlighting their independent source mechanisms. Our results imply that plume dynamics govern the charging for volcanic lightning, while the characteristics of the source explosion control vent discharges.
GNSS TEC‐Based Detection and Analysis of Acoustic‐Gravity Waves From the 2012 Sumatra Double Earthquake Sequence
Authors: Srivastava Sarthak , Chandran Amal , Manta Fabio , Taisne Benoit
Published: May 2021

The Wharton Basin earthquake sequence on April 11, 2012, offshore Sumatra, represents the two largest (Mw > 8.0) strike‐slip earthquakes ever recorded. Ground fault displacements generated a spectrum of acoustic‐gravity waves due to solid Earth–atmosphere coupling. Wave‐like perturbations in Total Electron Content (TEC) were therefore observed in ground‐based Global Positioning System data. The waves arrive about 10 min after each earthquake and their spectral analysis reveals the presence of acoustic resonance frequencies of 3.8 and 4.4 mHz. The acoustic wave speeds of 0.9–1.2 km/s suggest coseismic ground movement as the primary wave generating mechanism instead of seismic Rayleigh waves. Gravity waves with frequencies below 2 mHz traveling with lower speeds of 0.21 km/s are also detected. Ray tracing using a simple numerical model traced the source of observed ionospheric perturbations to within 150 km distance of the epicenters. Large amplitude ionospheric disturbances were found to travel mostly in a north‐south direction, an observation explained by the orientation of Earth’s geomagnetic field.
Assessing the Spatiotemporal Variability of Leaf Functional Traits and Their Drivers Across Multiple Amazon Evergreen Forest Sites: A Stochastic Parameterization Approach With Land‐Surface Modeling
Authors: Liu Shaoqing , Ng Gene‐Hua Crystal
Published: May 2021

Most earth system models fail to capture the seasonality of carbon fluxes in radiation‐limited tropical evergreen forests (TEF) in the Amazon. Kim et al. (2012, https://doi.org/10.1111/j.1365-2486.2011.02629.x) first statistically incorporated a light‐controlled phenology module into an ecosystem model to improve carbon flux simulations at one TEF site. However, it is not clear how their approach can be extended to other TEF sites with different climatic conditions. Here we evaluated temporal variability in plant functional traits at three different TEF sites using a data‐conditioned stochastic parameterization method. We showed that previously studied links—between seasonal photosynthetically active radiation (PAR) and the traits Vcmax25 and leaf longevity—occur across sites. We further determined that seasonal PAR could similarly drive variations in the stomatal conductance slope parameter. Differences found in temporal trait estimates among sites indicate that dynamic trait parameters cannot be applied uniformly over space, but it may be possible to extrapolate them based on climatic factors. Motivated by recent observations that physiological capacity develops as leaves mature, we built new regression models for predicting traits that not only include PAR but also an autoregressive lag term to capture observed physiological delays behind PAR‐driven phenology shifts. With our stochastic parameterization, we predicted the three sites to be carbon neutral or carbon sinks under the RCP 8.5 future climate scenario. In contrast, projections using standard static trait parameters show most of the Amazonian TEF region becoming a carbon source. We further approximated that variable traits may allow at least a third of the radiation‐limited TEF region in the Amazon to serve as a future net carbon sink.
The Chaos Beneath a Glacier’s Calving Front
Authors: Beurteaux Danielle
Published: May 2021

For the first time, researchers have captured continuous data on the abrupt changes and activities happening at a glacier’s calving front.
Caldera Collapse as the Trigger of Chaos and Fractured Craters on the Moon and Mars
Authors: Luzzi Erica , Rossi Angelo Pio , Massironi Matteo , Pozzobon Riccardo , Corti Giacomo , Maestrelli Daniele
Published: May 2021

Chaotic terrains are broad regions on Mars characterized by the disruption of the basaltic bedrock into polygonal blocks separated by deep fractures. To date, the proposed genetic scenarios often involve the occurrence of subsurface ice or liquid H2O. Nevertheless, similar features also occur within some craters on the Moon, namely floor‐fractured craters (FFCs), where water ice reservoirs are not present. We propose a new formation mechanism for Martian chaotic terrains as well as for lunar and Martian FFCs. The proposed mechanism does not require a major role of water but multiple cycles of inflation and deflation of a buried magma chamber. This process results in a particular type of caldera collapse, called the piecemeal (or chaotic) caldera collapse. A series of analog experiments show both geometrical and quantitative correspondence with natural case studies: Arsinoes Chaos (Mars), an unnamed FFC (Mars), and Komarov crater (FFC on the Moon).
Global Importance of Secondary Ice Production
Authors: Zhao Xi , Liu Xiaohong
Published: May 2021

Measured ice crystal number concentrations are often orders of magnitude higher than the number concentrations of ice nucleating particles, indicating the existence of secondary ice production (SIP) in clouds. Here, we present the first study to examine the global importance of SIP through the droplet shattering during freezing of rain, ice‐ice collision fragmentation, and rime splintering, using a global climate model. Our results show that SIP happens quite uniformly in the two hemispheres and dominates the ice formation in the moderately cold clouds with temperatures warmer than −15°C. SIP decreases the global annual average liquid water path by −14.6 g m−2 (−22%), increases the ice water path by 8.7 g m−2 (23%), improving the model agreement with observations. SIP changes the global annual average shortwave, longwave, and net cloud forcing by 2.1, −1.0, and 1.1 W m−2, respectively, highlighting the importance of SIP on cloud properties on the global scale.
Imaging the Hydrothermal System of Kirishima Volcanic Complex With L‐Band InSAR Time Series
Authors: Yunjun Zhang , Amelung Falk , Aoki Yosuke
Published: May 2021

We present deformation measurements of the Kirishima volcanic complex from ALOS and ALOS‐2 Interferometric Synthetic Aperture Radar (InSAR) time series during 2006–2019. Shinmoe‐dake deflated ∼6 cm during the 2008–2010 phreatic eruptions and inflated ∼5 cm prior to the 2017 magmatic eruption. Iwo‐yama inflated ∼19 cm within the crater since January 2015 and ∼7 cm around the southern and western vents since 4 months before the 2018 eruption. These deformations can be modeled as ellipsoids at ∼700 m depth beneath Shinmoe‐dake and as a sphere on top of an ellipsoid at ∼130 and ∼340 m depths beneath Iwo‐yama. Combining geodetic, geoelectric, geochemical, and petrological analysis, we interpret the hydrothermal origin of the deflation at Shinmoe‐dake and inflation at Iwo‐yama; the hydrothermal–magmatic transition during the 2011 Shinmoe‐dake eruption; and water‐boiling and bottom‐up pressurization as driving mechanisms of the inflation at Iwo‐yama. The study highlights the imaging potential of InSAR time series on complex hydrothermal systems.
The Three‐Dimensional Light Field Within Sea Ice Ridges
Authors: Katlein Christian , Langelier Jean‐Philippe , Ouellet Alexandre , Lévesque‐Desrosiers Félix , Hisette Quentin , Lange Benjamin A. , Lambert‐Girard Simon , Babin Marcel , Thibault Simon
Published: May 2021

Sea ice pressure ridges have been recognized as important locations for both physical and biological processes. Thus, understanding the associated light‐field is crucial, but their complex structure and internal geometry render them hard to study by field methods. To calculate the in‐ and under‐ridge light field, we combined output from an ice mechanical model with a Monte‐Carlo ray tracing simulation. This results in realistic light fields showing that light levels within the ridge itself are significantly higher than under the surrounding level ice. Light guided through ridge cavities and scattering in between ridge blocks also results in a more isotropic ridge‐internal light field. While the true variability of light transmittance through a ridge can only be represented in ray tracing models, we show that simple parameterizations based on ice thickness and macro‐porosity allow accurate estimation of mean light levels available for photosynthesis underneath ridges in field studies and large‐scale models.
How Frequent Are Antarctic Sudden Stratospheric Warmings in Present and Future Climate?
Authors: Jucker M. , Reichler T. , Waugh D. W.
Published: May 2021

Southern Hemisphere (SH) stratospheric sudden warmings (SSWs) result in smaller Antarctic ozone holes and are linked to extreme midlatitude weather on subseasonal to seasonal timescales. Therefore, it is of interest how often such events occur and whether we should expect more events in the future. Here, we use a pair of novel multimillennial simulations with a stratosphere‐resolving coupled ocean‐atmosphere climate model to show that the frequency of SSWs, such as observed 2002 and 2019, is about one in 22 years for 1990 conditions. In addition, we show that we should expect the frequency of SSWs, and that of more moderate vortex weakening events, to strongly decrease by the end of this century.
Natural Variability and Warming Signals in Global Ocean Wave Climates
Authors: Odériz I. , Silva R. , Mortlock T.R. , Mori N. , Shimura T. , Webb A. , Padilla‐Hernández R. , Villers S.
Published: May 2021

This paper presents a multivariate classification of the global wave climate into types driven by atmospheric circulation patterns. The primary source of the net long‐term variability is evaluated based on historical wave simulations. Results show that the monsoon, extratropical, subtropical, and polar wave climate types of the Pacific and North Atlantic Oceans are dominated by natural variability, whereas the extratropical and subtropical wave climate types in the Indian Ocean, and the tropical wave climate types of the Atlantic and Pacific Oceans exhibit a global warming signal. In the Pacific sector of the Southern Ocean, strong natural variability may mask a global warming signal that is yet to emerge as being statistically significant. In addition, wave climate teleconnections were found across the world that can provide a framework for joint strategies to achieve the goals of climate adaption for resilient coastal communities and environments.
Embedded Regions 1 and 2 Field‐Aligned Currents: Newly Recognized From Low‐Altitude Spacecraft Observations
Authors: Liu Jiang , Lyons L. R. , Wang Chih‐Ping , Ma Yuzhang , Strangeway R. J. , Zhang Yongliang , Kivelson M. , Zou Ying , Khurana K.
Published: May 2021

Regions 1 and 2 (R1 and R2) field‐aligned currents (FACs), manifestations of large‐scale convection in Earth's magnetosphere‐ionosphere (M‐I) system, often contain intense FAC layers of mesoscale latitudinal width near the R1/R2 interface. We refer to such layers as “embedded” R1 and R2 FACs. Likely resulting from enhanced magnetosphere‐ionosphere (M‐I) convection, these FACs may indicate M‐I configuration change and contribute significantly to substorm current wedges. We present several events in which embedded FACs were observed by low‐altitude spacecraft in the ionosphere. All the events occurred during active geomagnetic conditions or a substorm growth phase, and most map to an equatorial location on the nightside. When an embedded FAC is upward, it coincides with inverted‐V electron precipitation and a discrete auroral arc. If an upward embedded FAC is in the postmidnight‐to‐dawn sector, a dawnside auroral polarization stream appears immediately poleward of it, so it may be important for ionospheric heating, M‐I convection, and instabilities. Our results establish embedded FACs as a frequently appearing, fundamental phenomenon for understanding and modeling the magnetosphere‐ionosphere system.
Decoupling of Hf‐Nd Isotopes in Challenger Deep Sediments, Mariana Trench: Implications for Sedimentary Hf and Nd Recycling in Subduction Zones
Authors: Pang Chong‐Jin , Tian Liyan , Wang Xuan‐Ce , Zhang Hanyu , Wen Shu‐Nv , Krapež Bryan , Liu Wen‐Jing , Liu Zhi‐Xing , Wu Tao
Published: May 2021

Decoupling between Hf and Nd isotopes in trench sediments is an important way to produce, via subduction‐related recycling, the mantle chemical heterogeneity that is evident in many arc‐related magmas. Sediments collected from >7,000 m water depths on the southern and northern slopes of the Challenger Deep were analyzed to understand the factors controlling the variation in Hf and Nd isotopic compositions. These sediments were transported to both flanks of the Challenger Deep by synchronous density currents. All sediment samples show positive ɛHf values and negative ɛNd values, mostly plotting above the seawater and terrestrial arrays in Hf‐Nd isotope space. Hafnium isotopic compositions in each depositional unit vary (high up to 9.2 ɛHf units) from lower, coarse‐grained laminae to upper, fine‐grained graded intervals, showing a good correspondence between ɛHf values and lamination within depositional units. Such variations are explained by the concentration of Fe‐Mn oxyhydroxide‐bearing clays in the upper graded intervals, whereas diatom fragments and arc‐volcanic detritus are preferentially sorted into lower laminae. These findings demonstrate that the decoupling of Hf‐Nd isotopes in trench sediments is not only linked to the nature of provenance but also to hydrodynamic sorting processes during sediment transport. Our results suggest that geographical and stratigraphic variations in sedimentary components (resedimented density‐current deposits vs. oceanic pelagites), as well as overall grain size, of the subduction wedge can complicate Hf‐Nd isotopic decoupling in resulting arc magmas.
Determining the Shoreline Retreat Rate of Australia Using Discrete and Hybrid Bayesian Networks
Authors: Mao Yongjing , Harris Daniel L. , Callaghan David P. , Phinn Stuart
Published: May 2021

Evaluating shoreline retreat rate (SRR) on different spatial‐temporal scales is critical for effective coastal management. Large‐scale evaluations typically rely on data‐driven methods such as Discrete Bayesian networks (BNs). However, these BNs require discretization of continuous variables which can lead to information loss. Here, we propose a new method, the Hybrid BN to incorporate continuous variables without discretization. Both Discrete and Hybrid BNs were developed and compared to evaluate large‐scale (continental scale) SRR in Australia, using Digital Earth Australia data set. These BNs used forcing parameters (e.g., waves, tide, sediment sink/source, and sea level rise [SLR]) and geomorphic settings (e.g., geomorphology, backshore profile, and surfzone slope) to predict SRR. Validation of the BNs showed that Hybrid BNs, which provide a more realistic assessment of the range of SRR, outperform in predicting continuous variables, when compared with Discrete BNs. However, Discrete and Hybrid BNs provide consistent qualitative findings for the SRR of Australia. Among forcing parameters, the sediment sink/source was found to be the most informative variable to indicate the shoreline retreat, followed by tide, SLR rate, and wave processes. In the scenario of an increased SLR rate, tropical tidal flats were predicted as the most at risk coasts in Australia. We found that BNs can reflect the impact of different factors on coastal evolution, and predict future shoreline change by exploring historical data. The performance of these models can be further improved when more data sets become available.