bluuebunny/crossref_metadata_2025 huggingface dataset:
Laparoscopic duodenum–preserving pancreatic head resection with real-time indocyanine green guidance of different dosage and timing: enhanced safety with visualized biliary duct and its long-term metabolic morbidity
Authors: Lu Chao , Xu Biwu , Mou Yiping , Zhou Yucheng , Jin Weiwei , Xia Tao , Wang Yuanyu , Zhu Qicong , Fu Zhiqin
Published: July 2022

Purpose

Laparoscopic duodenum–preserving pancreatic head resection (L-DPPHR) is technically demanding with extreme difficulty in biliary preservation. Only a few reports of L-DPPHR are available with alarming bile leakage, and none of them revealed the long-term metabolic outcomes. For the first time, our study explored the different dosage and timing of indocyanine green (ICG) for guiding L-DPPHR and described the long-term metabolic results.

Methods

Between October 2015 and January 2021, different dosage and timing of ICG were administrated preoperatively and evaluated intra-operatively using Image J software to calculate the relative fluorescence intensity ratio of signal-to-noise contrast between bile duct and pancreas. Short-term complications and long-term metabolic disorder were collected in a prospectively maintained database and analyzed retrospectively.

Results

Twenty-five patients were enrolled without conversion to laparotomy or pancreaticoduodenectomy. Administrating a dosage of 0.5 mg/kg 24 h before the operation had the highest relative fluorescence intensity ratio of 19.3, and it proved to guide the biliary tract the best. Fifty-six percent of patients suffered from postoperative complications with 48% experiencing pancreatic fistula and 4% having bile leakage. No one suffered from the duodenal necrosis, and there was no mortality. When compared with the non-ICG group, the ICG group had a comparable diameter of tumor and similar safety distance from lesions to common bile duct; however, it decreased the incidence of bile leakage from 10% to none. The median length of hospital stay was 16 days. After a median follow-up of 26.6 months, no one had tumor recurrence or refractory cholangitis. No postoperative new onset of diabetes mellitus (pNODM) was observed, while pancreatic exocrine insufficiency (pPEI) and non-alcoholic fatty liver disease (NAFLD) were seen in 4% of patients 12 months after the L-DPPHR.

Conclusion

L-DPPHR is feasible and safe in selected patients, and real-time ICG imaging with proper dosage and timing may greatly facilitate the identification and the prevention of biliary injury. And it seemed to be oncological equivalent to PD with preservation of metabolic function without refractory cholangitis.
Neuromelanin granules of the substantia nigra: proteomic profile provides links to tyrosine hydroxylase, stress granules and lysosomes
Authors: Wulf Maximilian , Barkovits Katalin , Schork Karin , Eisenacher Martin , Riederer Peter , Gerlach Manfred , Eggers Britta , Marcus Katrin
Published: July 2022

Neuromelanin is a black-brownish pigment, present in so-called neuromelanin granules (NMGs) in the cell bodies of dopaminergic neurons in the substantia nigra (SN) pars compacta. These neurons are lost in neurodegenerative diseases, such as Parkinson’s disease and dementia with Lewy bodies. Although it is known that lipids, proteins, and environmental toxins accumulate in NMGs, the function of NMGs has not yet been finally clarified as well as their origin and the synthesis of neuromelanin. We, therefore, isolated NMGs and surrounding SN tissue from control patients by laser microdissection and analyzed the proteomic profile by tandem mass spectrometry. With our improved workflow, we were able to (1) strengthen the regularly reported link between NMGs and lysosomes, (2) detect tyrosine hydroxylase to be highly abundant in NMGs, which may be related to neuromelanin synthesis and (3) indicate a yet undescribed link between stress granules (SGs) and NMGs. Based on our findings, we cautiously hypothesize, that SGs may be the origin of NMGs or form in close proximity to them, potentially due to the oxidative stress caused by neuromelanin-bound metals.
Numerical simulation of hydraulic fracture height using cohesive zone method
Authors: Pham Son Tung , Nguyen Ba Ngoc Anh
Published: July 2022

Hydraulic fracturing is a popular method used in the petroleum industry to increase the well performance by improving the permeability of the reservoir. However, while there has been extensive research on the development of the length of the fracture, the fractured height has been frequently assumed to be equal to the reservoir thickness. The objective of this paper is to study the influence of formation rock characteristics and the impact of underground stress state on the development of the fracture height. To achieve this objective, a finite element model was built using a cohesive zone method to predict the development of fracture height in time and space. Different scenarios were then effectuated by varying the values of the primary formation variables which are the Young’s modulus, the porosity, the Poisson ratio, the fracture energy, and the maximum horizontal stress of the reservoir and of the beddings. This research therefore covered principally uncontrolled factors which are the formation properties and stress state underground, which contribute mostly to the erroneous prediction in fracture height. The findings revealed that the fracture height was strongly influenced by the properties of the formation and of the adjacent layers. However, the influence levels are not the same for different kinds of properties. This study showed that the most influential mechanical property of the rock on the fracture height is the Young’s modulus. Regarding the porosity, its effect on the fracture height is extremely small. However, it is worth noting that the porosity is still an important parameter in hydraulic fracturing because it can be used to estimate others parameters and to model the development of fracture geometry which are width, length, and height. Practical suggestions for real-life hydraulic fracturing jobs can be deduced from this study, in order to control the fracture height as accurately as possible, and to decrease financial cost by concentrating mostly on the high influential factors instead of doing all kinds of tests for other less influential mechanical properties of the rock.
4D seismic co-processing pre-stack depth migration for scarce acquisition repeatability
Authors: Mahgoub Mohamed , Bashir Yasir , Bery Andy Anderson , Noufal Abdel Wahab
Published: July 2022

Time-lapse (4D) seismic processing is routinely used to monitor hydrocarbon reservoir production. Seismic reflections are sensitive to formation pressure and fluid content. This means that repeated seismic surveys can theoretically detect pressure changes and fluid changes associated with field production. These measurements can help optimize production strategy and identify areas where hydrocarbons have been bypassed. However, the seismic signal associated with such changes can be negligible, especially in heterogeneous carbonate reservoirs. To measure this 4D signal, the seismic acquisition must be repeated. Data vintages should be processed together to minimize differences unrelated to production. Repeatability of data acquisition is sometimes impossible to achieve in the Middle East due to environmental changes (e.g., dunes, currents, field facilities). Due to high cost and inadequate sampling, attempts to permanently bury seismic sources and receivers have failed.

In this study, least-square pre-stack depth migration (LSM) co-processing was applied to remove the influence of survey design on the final image and pinching mark compared to conventional Kirchhoff pre-stack depth migration (KPSDM). The 4D physical, geometric, and seismic attributes are analyzed in the field as key diagnostic tools to evaluate the probability of a sighted 4D difference independent of two different acquisition geometries. The 4D analysis was performed on two case studies offshore Abu Dhabi, to determine which workflow and algorithm are most likely to ensure that the complete and optimal 4D processing sequence relaxes the need for seismic acquisition repeatability.
Developing a relationship between static Young’s modulus and seismic parameters
Authors: Sharifi Javad , Nooraiepour Mohammad , Amiri Mohammadkazem , Mondol Nazmul Haque
Published: July 2022

Mechanical properties of petroleum reservoirs can be determined via static techniques based on laboratory triaxial tests under reservoir conditions. Dynamic approaches represent an alternative in cases where such static laboratory data are unavailable. Dynamic elastic properties are calculated using ultrasonic wave measurements in the laboratory or in situ well logging. Different relationships have been proposed to estimate static properties from dynamic ones based on the available data from a particular reservoir. However, these relationships are often reservoir-specific, making them inadequate for general seismic inversion purposes. This research proposes a method for developing relationships between seismic parameters and static Young’s modulus in carbonate reservoirs by integrating ultrasonic measurements, well logging data, and rock mechanic tests. A multistage triaxial test simulating the reservoir conditions was used to fully control the stress and strain during the geomechanical experiments. Static Young’s modulus was cross-correlated with a broad spectrum of seismic parameters that can be extracted from seismic inversion (e.g., acoustic impedance, shear impedance, Lambda–rho, and mu–rho). Separate analytic relationships were proposed to convert dynamic Young’s modulus and seismic parameters into static Young’s modulus. Analysis of variance was used to evaluate the results and study the applicability and reliability of the obtained relationships. Furthermore, the reliability of the obtained relationships was successfully confirmed by well logging data and blind well analysis. The proposed methodology can be used to predict rock behavior for geomechanical and structural modeling.
Demonstration of a ZnO-Nanowire-Based Nanograting Temperature Sensor
Authors: Cao Hongqian , Li Danran , Zhou Kanghu , Chen Ye
Published: July 2022

In this study, we experimentally demonstrate a miniature fiber thermometer based on tip-integrated ZnO-nanowire-nanograting. The sensor has a diameter less than 1 µm and the length of the Bragg grating is sub-10 µm. The ZnO-nanowire-nanograting is sensitive to the environmental temperature change. Thus, the intensity of the light whose wavelength is in the rising or falling region of the nanograting spectrum will vary with the shift in wavelength due to change in temperature. Taking one wavelength (655 nm) in the rise linear region of the nanograting spectrum, a sensitivity of 0.066 nW/°C in the air is achieved experimentally. The proposed temperature sensor has the superiorities of compactness, stableness, and easy fabrication compared to regular fiber grating sensors, offering great potential for detecting inside minimal volume environments.
Association of white matter hyperintensities with migraine phenotypes and response to treatment
Authors: Ahmed Sherihan Rezk , Mohamed Amr Abdel Monem , Salem Haitham Hamdy , Helmy Shahinaz , Moustafa Ramez Reda , Borham Sherien Mohamed Farag
Published: July 2022

Introduction

White matter hyperintensities (WMHs) are frequently found in migraineurs. However, their clinical significance and correlation to different migraine phenotypes and treatment responses are not well defined. The study aimed to examine the association of WMHs with migraine clinical patterns and treatment response.

Aim of work

We aimed to evaluate the association between WMHs and migraine phenotypes and explore the relationship of WMHs to treatment response.

Methods

Our cross-sectional study formed of 500 migraineurs who sought treatment in Kafr el-sheik university hospital and underwent (3 T) MRI to evaluate WMHs. Different migraine phenotypes were compared between patients with and without WMHs. According to reduced headache pain intensity and frequency, these patients were divided into treatment responder and non-responder groups.

Results

A total of 145 patients (29%) had WMHs. Patients with WMHs were significantly older, had a longer disease duration, and higher attack frequency. Patients who did not respond to acute and maintenance medications had a higher frequency of WMHs and high WMHs Scheltens score. Migraine with Aura and the presence of vomiting and dizziness were predictors for the development of WMHs.

Conclusion

WMHs are more common in migraine with aura. It is more frequent in migraine associated with vomiting and dizziness. WMHs increased with advancing age and more severe disease burden. Poorer response to acute and prophylactic medications was found in patients with WMHs.
Synthetic Control Methodology for Examining Firearm Policy
Authors: Esposti Michelle Degli , Wiebe Douglas , Kaufman Elinore , Bonander Carl
Published: July 2022

Purpose of Review

Firearm policies have the potential to alleviate the public health burden of firearm violence, yet it is unclear which policies are effective. The current review aims to summarize studies that use synthetic control methods to overcome previous methodological limitations when examining the impacts of firearm policies.

Recent Findings

Evidence from studies using synthetic control methods find compelling evidence that purchasing licensing laws for all individuals (e.g., permit-to-purchase) have a preventive effect on firearm deaths. Otherwise, the effects of other firearm policies targeting firearm availability, ownership, sales, and use varied across studies and contexts.

Synthetic control evaluations find heterogenous effects of firearm policies, suggesting that previous inconsistent findings might reflect their varying impacts across regions rather than methodological limitations alone. Future research should aim to exploit the complementary biases of synthetic control methods to triangulate evidence across evaluation approaches and understand why firearm policies have differential impacts.
An interpretation of quantum foundations based on density functional theory and polymer self-consistent field theory
Authors: Thompson Russell B.
Published: July 2022

The Feynman quantum-classical isomorphism between classical statistical mechanics in 3+1 dimensions and quantum statistical mechanics in 3 dimensions is used to connect classical polymer self-consistent field theory with quantum time-dependent density functional theory. This allows the theorems of density functional theory to relate non-relativistic quantum mechanics to a classical statistical mechanical derivation of polymer self-consistent field theory for ring polymers in a 4 dimensional thermal-space. One dynamic postulate is added to two static postulates which allows for a description of quantum physics from a 5 dimensional thermal-space-time ensemble perspective. A connection with aspects of classical field theory can be made in the classical limit.
Bariatric surgery for metabolic unhealthy obesity (MUO) during the COVID era: short-term results of a high-volume center
Authors: Guglielmi Valeria , Campanelli Michela , Bianciardi Emanuela , Benavoli Domenico , Colangeli Luca , D’Adamo Monica , Sbraccia Paolo , Gentileschi Paolo
Published: July 2022

Purpose

During the coronavirus disease 19 (COVID-19) outbreak, most public hospitals worldwide have been forced to postpone a major part of bariatric surgery (BS) operations with unfavorable consequences for weight and obesity complications. The aim of this study was to evaluate the effectiveness and safety of laparoscopic BS on subjects with metabolically unhealthy obesity (MUO) during COVID-19 pandemic in a high-volume Italian center.

Methods

Between March 2020 and January 2021, all patients with MUO submitted to laparoscopic BS (sleeve gastrectomy [SG], one anastomosis gastric bypass [OAGB] and Roux-en-Y gastric bypass [RYGB]) were enrolled according to the ATP III Guidelines, with a minimum follow-up of 3 months.

Results

In the study period, 210 patients with MUO underwent laparoscopic BS (77 RYGB, 85 SG and 48 OAGB) in our obesity referral center. Postoperative major complications occurred in 4 patients (1.9%) with zero mortality. At 9-month follow-up, a total weight loss (TWL) of 28.2 ± 18.4, 26.1 ± 23.1 and 24.5 ± 11.3% (p = 0.042) was observed in RYGB, OAGB and SG groups, respectively. The rate of comorbidity resolution was very similar for all type of surgeries (p = 0.871). Only two cases of postoperative SARS-CoV-2 infection were registered (0.9%) and both cases resolved with medical therapy and observation.

Conclusion

Among the patients studied, all surgical techniques were safe and effective for MUO during the COVID era. This group of patients is at high risk for general and SARS-CoV-2-related mortality and therefore should be prioritized for BS.

Level of evidence

Level III, single-center retrospective cohort study.
Bracing for juvenile idiopathic scoliosis: retrospective review from bracing to skeletal maturity
Authors: Whitaker Amanda T. , Hresko Michael Timothy , Miller Patricia E. , Verhofste Bram P. , Beling Alexandra , Emans John B. , Karlin Lawrence I. , Hedequist Daniel J. , Glotzbecker Michael P.
Published: July 2022

Background

Juvenile idiopathic scoliosis (JIS) outcomes with brace treatment are limited with poorly described bracing protocols. Between 49 and 100% of children with JIS will progress to surgery, however, young age, long follow-up, and varying treatment methods make studying this population difficult. The purpose of this study is to report the outcomes of bracing in JIS treated with a Boston brace™ and identify risk factors for progression and surgical intervention.

Methods

This is a single-center retrospective review of 175 patients with JIS who initiated brace treatment between the age of 4 and 9 years. A cohort of 140 children reached skeletal maturity; 91 children had surgery or at least 2 year follow-up after brace completion. Standard in-brace protocol for scoliosis 320° was a Boston brace for 18–20 h/day after MRI (n = 82). Family history, MRI abnormalities, comorbidities, curve type, curve magnitude, bracing duration, number of braces, compliance by report, and surgical interventions were recorded.

Results

Children were average 7.9 years old (range 4.1–9.8) at the initiation of bracing. The Boston brace™ was prescribed in 82 patients and nine used night bending brace. Mid-thoracic curves (53%) was the most frequent deformity. Maximum curve at presentation was on average 30 ± 9 degrees, in-brace curve angle was 16 ± 8 degrees, and in-brace correction was 58 ± 24 percent. Patients were braced an average of 4.6 ± 1.9 years. 61/91 (67%) went on to posterior spinal fusion at 13.3 ± 2.1 (range 9.3–20.9) years and curve magnitude of 61 ± 12 degrees. Of those that underwent surgery, 49/55 (86%) progressed > 10°, 6/55 (11%) stabilized within 10°, and 0/55 (0%) improved > 10° with brace wear. No children underwent growth-friendly posterior instrumentation. Of the 28 who did not have surgical correction, 3 (11%) progressed > 10°, 13/28 (46%) stabilized within 10°, and 12/28 (43%) improved > 10° with brace wear.

Conclusions

This large series of JIS patients with bracing followed to skeletal maturity with long-term follow-up. Surgery was avoided in 33% of children with minimal to no progression, and no child underwent posterior growth-friendly constructs. Risk factors of needing surgery were noncompliance and larger curves at presentation.
Music Listening Was an Emotional Resource and Social Surrogate for Older Adults During the COVID-19 Pandemic: A Qualitative Study
Authors: Groarke Jenny M. , MacCormac Niamh , McKenna-Plumley Phoebe E. , Graham-Wisener Lisa
Published: July 2022

Loneliness and isolation worsen health and wellbeing have been exacerbated by COVID-19, and represent a significant concern for supporting older adults. Music listening has effects that could be particularly supportive during periods of isolation. The aim of this study is to examine older adults’ music listening behaviour during the COVID-19 pandemic and explore music's social and emotional impact in this context. Semi-structured interviews enhanced with music-elicitation were carried out remotely between May and June 2021. Participants were self-selected, community-dwelling older adults residing in Northern Ireland (N= 14; 6 males; 60–83 years). Most were living with their spouse or family, all were of White ethnicity and had varying levels of education. Data were analysed using reflexive thematic analysis. Two main themes were identified: (1) Music as an emotional resource and (2) Music as a social surrogate. Older adults had a preference for using music to induce positive feelings, and used music for negative affect regulation and consolation. Music acted as a social surrogate providing company, and reminders of social relationships and experiences. Music listening was a valued behaviour during COVID-19. Findings have implications for how music listening might be used as an accessible, low-resource tool for supporting isolated older adults.
The RIC COVID-19 Recruitment & Retention Toolkit: A community-informed resource of recruitment tools and strategies for clinical trial investigators
Authors: Kennedy Nan , Dunagan Julia , Boone Leslie R. , Israel Tiffany , Mayers Stephanie A. , Dunkel Leah , Cook Sarah , Pimentel Pamela , Edwards Terri L. , Stroud Mary , Wilkins Consuelo H. , Harris Paul A.
Published: July 2022

The Recruitment Innovation Center (RIC) has created a toolkit of novel strategies to engage potential participants in response to recruitment and retention challenges associated with COVID-19 studies. The toolkit contains pragmatic, generalizable resources to help research teams increase awareness of clinical trials and opportunities to participate; produce culturally sensitive and engaging recruitment materials; improve consent and return of results processes; and enhance recruitment of individuals from populations disproportionately impacted by COVID-19. This resource, the “RIC COVID-19 Recruitment and Retention Toolkit,” is available free online. We describe the toolkit and the community feedback used to author and curate this resource.
‘A Single Purpose: The Conquest of the Foreign Art Markets’: Theatre and Cultural Diplomacy in Mussolini’s Italy (1919–1927)
Authors: Paoletti Matteo
Published: July 2022

This article explores the role of theatre in the strategies of cultural diplomacy that developed in Italy between the last years of the liberal state (1919–22) and the rise of Benito Mussolini. It covers the period until 1927, when the establishment of the Istituti Italiani di Cultura (Italian Cultural Institutes) and the approval of a new regulatory framework for migration marked a new era for fascist soft-power ambitions. The article draws upon unpublished sources of the Historical Diplomatic Archive of the Italian Ministry of Foreign Affairs and offers a new perspective on the use of theatre and the performing arts as a tool for cultural diplomacy through the testimony of such flagship authors as Luigi Pirandello, Filippo Tommaso Marinetti, Alfredo Casella, and Pietro Mascagni. Matteo Paoletti is a Senior Assistant Professor in Theatre Studies at the University of Bologna and part of the research project ‘Historia y patrimonio de la Argentina moderna’ with the Universidad Nacional de San Martín, Buenos Aires. He was a Cultural Attaché at the Italian Ministry of Foreign Affairs, and oversaw the 2003 Convention on Intangible Cultural Heritage for the Italian National Commission for UNESCO. His recent publications include ‘A Huge Revolution of Theatrical Commerce’: Walter Mocchi and the Italian Musical Theatre Business in South America (Cambridge University Press, 2020)
Validation of salt intake measurements: comparisons of a food record checklist and spot-urine collection to 24-h urine collection
Authors: Beer-Borst Sigrid , Hayoz Stefanie , Gréa Krause Corinna , Strazzullo Pasquale
Published: July 2022

Objective:

Monitoring population salt intake is operationally and economically challenging. We explored whether a questionnaire assessment and a prediction of Na intake from spot-urine could replace or complement the recommended measurement of Na in 24-h urine (24-h U).

Design:

Compare the agreement of a Na-specific food record checklist (FRCL) and a late-afternoon spot-urine measurement (PM-spot) with 24-h U measurement in estimating Na intake at group level. Each participant’s use of these methods extended over 3 d. Agreement was assessed using mean (95 % CI) differences, linear regression models and Bland–Altman plots.

Setting:

The validation study was part of a 1-year workplace intervention trial to lower salt intake in Switzerland.

Participants:

Seventy women and 71 men, aged 21–61 years, completed three FRCL, and acceptable PM-spot and 24-h U samples at baseline (April–October 2015).

Results:

Mean Na intake estimates varied slightly across methods (3·5–3·9 g/d). Mean Na intake differences from 24-h U were 0·2 (95 % CI (0, 0·5)) g/d for FRCL and 0·4 (95 % CI (0·2, 0·6)) g/d for PM-spot. Linear regression models and Bland–Altmann plots more clearly depicted differences by sex and discretionary salt use.

Conclusions:

Although 24-h U remains the best reference method for monitoring Na intake at the population level, PM-spot and FRCL might be more practical instruments for frequent, periodic Na intake assessments. Population-specific prediction models to estimate 24-h U could be developed and evaluated.
Igniting Change: An Evangelical Megachurch’s Racial Justice Program
Authors: Han Hahrie , Arora Maneesh
Published: July 2022

Congregations, with their size, breadth, and legacy of shaping political activism, have the potential to be important sites of action for addressing racial injustice in America. Yet historical legacies of racism and persistently high levels of racial animus have made white evangelical communities in particular resistant to addressing racism. Most efforts to address racism in these communities begin with prejudice reduction programs that often fail. Utilizing a mixed-methods approach, we examine the effectiveness of a different kind of six-week racial justice program in one of the nation’s largest evangelical megachurches that focuses on animating action among people open to tackling racial injustice in their church. We find that program participation is associated with increased feelings of efficacy, amplified perceptions of community, a greater commitment to cross-racial perspective taking, and greater likelihood of engaging in meaningful action. We argue that the program works by focusing on cross-racial relationship building to equip a people pre-disposed to action to actually take action. Developing such leaders is potentially the first step in a program other congregations can take to tackle racial injustice.
A Lacunarity‐Based Index for Spatial Heterogeneity
Authors: Scott R. , Kadum H. , Salmaso G. , Calaf M. , Cal R. B.
Published: July 2022

Characterizing spatial heterogeneity is fundamental in numerous areas, yet defining spatial patterns often depends on qualitative assessments or a priori knowledge. Lacunarity analysis is a popular occupancy‐based method for identifying relevant length scales in spatially heterogeneous systems. From lacunarity, we identify the existence of a point which encapsulates the spatial heterogeneity of a given system. This value satisfies the conditions for the lacunarity cutoff function and forms the basis of a heterogeneity index. We evaluate the behavior of both parameters in monofractal, clustered, and periodic systems. In addition, we demonstrate the broad utility of our approach to the scientific community by classifying the spatial heterogeneity of fractured sea ice and comparing our findings to existing measures. The heterogeneity index produced a linear correlation with the area fraction of open ocean to ice with an R2 of 0.967.
Multi‐Centennial Variability of Yangtze Delta Growth Over the Last 2000 Years: Interplay of Climate and People
Authors: Nian Xiaomei , Zhang Weiguo , Wang Xiaoting , Hutchinson Simon M. , Zhao Xuanqi , Liu Kam‐biu
Published: July 2022

Reconstruction of sediment accumulation in river deltas over the Holocene provides a basis for understanding the relationship between climate change, human activities and delta growth. However, variations in deposition rates on a centennial‐scale over the last 2000 years remain poorly studied for mega‐deltas. Based on optically stimulated luminescence and AMS 14C ages, we calculated deposited sediment volumes in the Yangtze River Delta (YRD) for 500‐year intervals over the last two millennia for the first time. Our results reveal that the 2.0–1.5 and 0.5–0 ka periods had higher sediment deposition rates than in 1.5–1.0 and 1.0–0.5 ka, with maximum value about two times that of the minimum. A comparison with historical records of flooding and drought events indicates that a wetter climate led to a higher sediment deposition, reflecting the role of fluvial discharge in delta growth. However, the highest sediment deposition (205 ± 29 × 106 m3/a) over the last 500 years is not only related to the wetter conditions of the Little Ice Age, but also linked to dramatic regional population growth. We suggest that human activities have predominated over natural forcing in determining the deltaic growth over the last five centuries. Taking the Medieval Climate Anomaly with the lowest deposition volume as an analog of current climate warming, and considering the decline in sediment loads due to recent damming and soil conservation, the YRD is likely to face an even more severe deficit in sediment supply and higher risk of delta destruction in the coming centuries.
Impact of the Ensemble Kalman Filter Based Coupled Data Assimilation System on Seasonal Prediction of Indian Summer Monsoon Rainfall
Authors: Gade Sagar V. , Sreenivas Pentakota , Rao Suryachandra A. , Srivastava Ankur , Pradhan Maheswar
Published: July 2022

The sensitivity of seasonal prediction (June to September) of Indian monsoon to initial state from two variants of coupled data assimilation (CDA) products, viz. the Climate Forecast System (CFS) Reanalysis (CFSR) and Indian Institute of Tropical Meteorology, University of Maryland‐ Weakly Coupled Analysis (IWCA) is explored in this study. The IWCA implements the local ensemble transform Kalman filter, and incorporates theoretically advanced features of flow‐dependency and ensemble‐based analysis compared to CFSR. The CFS version‐2 predictions using IWCA simulate the large‐scale monsoon features, and convection centers well, and improve prediction skills compared to CFSR predictions. The enhanced analysis quality and Ocean‐Atmospheric cross‐domain equilibrium in IWCA reduce initial shocks in springtime predictions. Further, the sustained ensemble consistency aided to simulate the variability better and improved the seasonal predictions. The study strongly advocates the adaptation of advanced CDA methods for seasonal monsoon and probable seamless predictions.
Achievements and Prospects of Global Broadband Seismographic Networks After 30 Years of Continuous Geophysical Observations
Authors: Ringler A. T. , Anthony R. E. , Aster R. C. , Ammon C. J. , Arrowsmith S. , Benz H. , Ebeling C. , Frassetto A. , Kim W.‐Y. , Koelemeijer P. , Lau H. C. P. , Lekić V. , Montagner J. P. , Richards P. G. , Schaff D. P. , Vallée M. , Yeck W.
Published: July 2022

Global seismographic networks (GSNs) emerged during the late nineteenth and early twentieth centuries, facilitated by seminal international developments in theory, technology, instrumentation, and data exchange. The mid‐ to late‐twentieth century saw the creation of the World‐Wide Standardized Seismographic Network (1961) and International Deployment of Accelerometers (1976), which advanced global geographic coverage as seismometer bandwidth increased greatly allowing for the recording of the Earth's principal seismic spectrum. The modern era of global observations and rapid data access began during the 1980s, and notably included the inception of the GEOSCOPE initiative (1982) and GSN (1988). Through continual improvements, GEOSCOPE and the GSN have realized near‐real time recording of ground motion with state‐of‐art data quality, dynamic range, and timing precision to encompass 180 seismic stations, many in very remote locations. Data from GSNs are increasingly integrated with other geophysical data (e.g., space geodesy, infrasound and Interferometric Synthetic Aperture Radar). Globally distributed seismic data are critical to resolving crust, mantle, and core structure; illuminating features of the plate tectonic and mantle convection system; rapid characterization of earthquakes; identification of potential tsunamis; global nuclear test verification; and provide sensitive proxies for environmental changes. As the global geosciences community continues to advance our understanding of Earth structure and processes controlling elastic wave propagation, GSN infrastructure offers a springboard to realize increasingly multi‐instrument geophysical observatories. Here, we review the historical, scientific, and monitoring heritage of GSNs, summarize key discoveries, and discuss future associated opportunities for Earth Science.
Diffuse Radiation Forcing Constraints on Gross Primary Productivity and Global Terrestrial Evapotranspiration
Authors: Chakraborty T. , Lee X. , Lawrence D. M.
Published: July 2022

The diffuse radiation fertilization effect—the increase in plant productivity in the presence of higher diffuse radiation (K↓,d)—is an important yet understudied aspect of atmosphere‐biosphere interactions and can modify the terrestrial carbon, energy, and water budgets. The K↓,d fertilization effect links the carbon cycle with clouds and aerosols, all of which are large sources of uncertainties for our current understanding of the Earth system and for future climate projections. Here we establish to what extent observational and modeling uncertainty in sunlight's diffuse fraction (kd) affects simulated gross primary productivity (GPP) and terrestrial evapotranspiration (λE). We find only 48 eddy covariance sites with simultaneous sufficient measurements of K↓,d with none in the tropical climate zone, making it difficult to constrain this mechanism globally using observations. Using a land modeling framework based on the latest version of the Community Land Model, we find that global GPP ranges from 114 Pg C year−1 when using kd forcing from the Modern‐Era Retrospective analysis for Research and Applications, version 2 reanalysis to a ∼7% higher value of 122 Pg C year−1 when using the Clouds and the Earth's Radiant Energy System satellite product, with especially strong differences apparent over the tropical region (mean increase ∼9%). The differences in λE, although smaller (−0.4%) due to competing changes in shaded and sunlit leaf transpiration, can be greater than regional impacts of individual forcing agents like aerosols. Our results demonstrate the importance of comprehensively and systematically validating the simulated kd by atmosphere modules as well as the response to differences in kd within land modules across Earth System Models.
Inverse Magnetic Fabrics Caused by Magnetofossils in the Northwestern South China Sea Since End of the Last Glacial
Authors: Wang Haosen , Xu Xing , Gai Congcong , Liu Jiabo , Zhong Yi , Jiang Xiaodong , Zhang Yanan , Ferré Eric C. , He Kuang , Liu Qingsong
Published: July 2022

The relationships among the abundance of magnetofossils, the ensuing magnetic properties, and the controlling paleoenvironmental factors in marine sediments remain broadly unexplored. Here, we identify magnetofossils in core XB1 from the northwestern South China Sea (SCS) since end of the Last Glacial. Using rock magnetic and electron microscopic data, we propose a model that links the anisotropy of magnetic susceptibility fabric and the abundance of magnetofossils. The magnetofossil concentration in sediments increases significantly during the 14.7–4.7 ka period, which in turns leads to inverse magnetic fabrics and near‐horizontal of the minimum magnetic susceptibility axes. Further, we show that the abundance of magnetofossils is linked to paleoenvironmental changes in the northwestern SCS. The production and preservation of magnetofossils during the 14.7–4.7 ka period are promoted by an intensified East Asian summer monsoon and sluggish deep‐water ventilation, while the paucity of magnetofossils after 4.7 ka is attributed to high oxygen content.
More Intense, Organized Deep Convection With Shrinking Tropical Ascent Regions
Authors: Wodzicki Kyle R. , Rapp Anita D.
Published: July 2022

Changes in the frequency and morphology of convection in a warming climate have major implications for the hydrologic cycle and continue to be a large source of variability in climate models. Recent studies of model output indicate a narrowing and intensification of the ascending branch of the Hadley circulation (i.e., the Intertropical Convergence Zone). The present work uses tropical ascent area fraction (Au) and Tropical Rainfall Measurement Mission precipitation features to study global tropical variability in convection with ascent area changes in the current climate. Ascent region convection becomes more intense and organized when Au is low. Overall increases in mean precipitation as the tropical ascent regions shrink are primarily driven by an increase in the areal extent of convective systems, rather than intensity of the convective system rainfall, suggesting an increase in the organization and aggregation of convection as the climate continues to warm.
Severe Drought Conditions in Northern East Asia During the Early Pliocene Caused by Weakened Pacific Meridional Temperature Gradient
Authors: Zheng Yanhong , Fedorov Alexey V. , Burls Natalie J. , Zhang Rui , Brierley Chris M. , Fang Zhengkun , Yu Xuefeng , Xian Feng , Lu Hongxuan
Published: July 2022

The evolution of hydroclimate in East Asia during the Pliocene—a potential analog of the future greenhouse climate—remains highly uncertain. Here we reconstruct changes in the hydroclimate of Northern China during this epoch. Our results reveal previously undocumented severe drought conditions that persisted through the early Pliocene with a significantly greater magnitude than suggested by other records. Using a broad hierarchy of climate simulations, we find that reduction in the Pacific meridional sea surface temperature (SST) gradient has particularly strong impacts on precipitation over Northern China, which suggests its key role in maintaining drought conditions during the early Pliocene. The weaker Pacific meridional SST gradient causes the weakening of the East Asian summer monsoon precipitation over this region via a reduction of atmospheric northward moisture transport from the ocean, which enhances aridity inland. Our results highlight the fundamental control of the tropical ocean on the extra‐tropical hydrological cycle.
Varying Shear Wave Splitting Parameters Suggest Interaction Between Lithosphere and Asthenosphere in Arxan‐Chaihe Volcanic Field, NE China
Authors: Qiang Zhengyang , Wu Qingju , Li Yonghua , Zhang Fengxue
Published: July 2022

Over 2 years of broadband seismic data from 27 temporary stations deployed in the Arxan‐Chaihe Volcanic Field (ACVF) provides us a valued opportunity to study mantle deformation and related geodynamic processes in NE China intraplate region. We estimated 153 pairs of high‐quality teleseismic shear wave splitting parameters at 22 stations and 98 non‐splitting measurements at 19 stations. Most of the stations in ACVF are characterized by NNW–SSE trending fast directions with variable splitting delay times, suggesting the fossilized extensional deformation within the lithosphere is locally thermal erased by the hot mantle upwellings associated with the volcanism. In the region south of the 46.5°N, a sharp swing of fast polarization occurs, and both nearly NW‐SE and W‐E oriented fast directions are observed, which could be explained by small local mantle convection caused by the lithospheric delamination.
Fluid‐Enhanced Neotectonic Faulting in the Cratonic Lithosphere of the Nullarbor Plain in South‐Central Australia
Authors: Yang H. , Sellmann S. , Quigley M.
Published: July 2022

The Nullarbor Plain is underlain by thick cratonic lithospheric mantle that is almost devoid of contemporary seismicity. Analysis of high‐resolution digital elevation models indicates neotectonic fault‐propagation fold traces on the nearly flat karst landscape that locally extend to lengths of >100 km, suggesting potential for hosting large (>7.3–7.5) moment magnitude earthquakes. Along‐strike maximum displacements are not proportional to neotectonic fold surface trace length but are spatially associated with crust‐scale electrical conductors identified in magnetotelluric surveys. Two major conductors penetrate from the upper crust to the uppermost mantle (at depths < 60 km) along crustal scale shear zones. Conductivity in the uppermost mantle shear zones is higher than conductivity at increased depth, suggesting fluid‐enhanced enrichment with hydrogen and/or carbon. Lithospheric fluid localization associated with ancient slab subduction and/or hydrothermal alteration may have weakened pre‐existing faults and enhanced neotectonic faulting in the Nullarbor Plain.
Vertical Propagation Speeds of Gravity Waves in the Daytime as a Precursor to the Onset of the Equatorial Spread‐F
Authors: Mandal Subir , Pallamraju Duggirala , Pant Tarun Kumar
Published: July 2022

The equatorial spread‐F (ESF) refers to the spread observed in return echoes of ionograms. Such spread in reflected echoes is found both in range and frequency, which can last for a few hours. These are due to large‐scale plasma irregularities occurring in the ionospheric heights on some nights. Under seemingly identical background conditions, ESF might occur on one night but remain absent on the other. These plasma irregularities adversely affect the trans‐ionospheric radio wave propagation but their occurrence on a given night continues to be one of the missing elements in our understanding of the equatorial ionospheric phenomena. In this work, the vertical propagation of gravity waves in daytime thermosphere has been shown to be a crucial parameter for the generation of ESF during post‐sunset hours. Using electron density profiles obtained from digisonde at Trivandrum, a dip‐equatorial location in India, we found that vertical propagation activity of gravity waves exists on 85% of the ESF days, whereas it is only 50% for the days without the occurrence of ESF during post‐sunset hours. Further, vertical propagation speeds of these gravity waves are higher on the ESF days than on the non‐ESF days. Also, ESF has been found to occur on 100% of the occasions, whenever the vertical speeds of these gravity waves are greater than 80 ms−1. This threshold value of vertical propagation speeds of gravity waves can be used to predict the ESF occurrence around 12–14 LT on that day, which is much in advance of the occurrence of ESF.
Combined Scattering of Suprathermal Electrons by Whistler‐Mode Chorus and Electromagnetic Ion Cyclotron Waves in the Low‐Density Plasmatrough
Authors: Yu Jiang , Wang Jing , He Zhaoguo , Liu Nigang , Li Kun , Ren Aojun , Li Liuyuan , Cui Jun , Cao Jinbin
Published: July 2022

Based on the observation from Van Allen Probes, we report an event of intense and simultaneous electromagnetic ion cyclotron (EMIC) and chorus waves inside the low‐density plasmatrough. By calculating the scattering rates and performing the diffusion simulations, we for the first time evaluate the combined scattering of suprathermal electrons by EMIC and chorus waves in the low‐density plasmatrough. Landau acceleration of suprathermal electrons by EMIC waves is mainly restricted at large pitch angles while their scattering loss by chorus waves occurs at small pitch angles well below 90°. When EMIC and chorus waves are simultaneously present, the scattering of suprathermal electrons by the two waves is very different from that by each type of waves alone. EMIC waves play a complementary role in the scattering of suprathermal electrons by chorus waves, which facilitate the scattering of suprathermal electrons over all pitch angles. The near‐equatorially minoring suprathermal electrons are firstly scattered toward intermediate pitch angles by EMIC waves and further toward the loss cone by chorus waves. Our results highlight the complementary role of different types of magnetospheric waves in the suprathermal electron scattering, which potentially have vital implications for the dynamics of suprathermal electrons in the planetary magnetosphere.
Parametric Model for Eddies‐Induced Sound Speed Anomaly in Five Active Mesoscale Eddy Regions
Authors: Chen Wen , Zhang Yongchui , Liu Yuyao , Ma Lina , Wang Haodi , Ren Kaijun , Chen Shiyao
Published: July 2022

Mesoscale eddies are ubiquitous in the ocean. Their acoustic properties have attracted considerable research attention. However, the three‐dimensional structure for eddy‐induced sound speed anomalies has remained obscure, hindering further understanding of the impact of eddies on acoustic propagation. To solve this problem, a region‐dependent parametric model for eddy‐induced sound speed anomaly (SSA) structure is established by performing a composite analysis based on abundant profiles measured by Argo floats and the corresponding satellite altimetry data. The parametric SSA model can be applied to fast reconstruct the underwater sound speed (SS) field of the eddy based only on the intensity and radius of the eddy. A comparison with a surveyed eddy shows that the errors of the reconstructed SSA are 2.36 m/s (8.33%) in strength and 37 m (9.37%) in core depth. The reconstructed SS field is employed to study the sound propagation characteristics in the presence of a cyclonic eddy with the ray‐tracing method. The results show that the parametric model can advance eddy‐acoustic effect research in the case of observation data shortages.
Melt Production and Ejection From Lunar Intermediate‐Sized Impact Craters: Where Is the Molten Material Deposited?
Authors: Liu T. , Luther R. , Manske L. , Wünnemann K.
Published: July 2022

Differently aged impact melt in lunar samples is key to unveiling the early bombardment history of the Moon. Due to the mixing of melt products ejected from distant craters, the interpretations of the origin of lunar samples are difficult. We use numerical modeling for a better quantitative understanding of the production of impact‐induced melt and in particular its distribution in ejecta blankets for lunar craters with sizes ranging from 1.5 to 50 km. We approximate the lunar stratigraphy with a porosity gradient, which represents the gradual transition from upper regolith via megaregolith to the solid crustal material. For this lunar setting, we quantify the melt production relative to crater volume and derive parameters describing its increasing trend with increasing transient crater size. We found that about 30%–40% of the produced melt is ejected from the crater. The melt concentration in the ejecta blanket increases almost linearly with distance from the crater center, while the thickness of the ejecta blanket decreases following a power law. Our study demonstrates that if in lunar samples the concentration of a melt with a certain age is interpreted to be of a nonlocal origin, these melts could be the impact products of a large crater (>10 km) located hundreds of kilometers away.
SRF2—A Short‐Term (1–24)h foF2 Prediction Method
Authors: Perrone L. , Mikhailov A. V.
Published: July 2022

A sunrise F2‐layer short‐term (1–24) h foF2 prediction method has been developed to forecast foF2 variations at a given ionosonde station during magnetically quiet and disturbed periods. The proposed method efficiently describes both positive and negative quiet time F2‐layer disturbances under daily Ap <30 nT and this was done for the first time. A comparison with modern global empirical models demonstrates a statistically significant advantage over them under various seasons and levels of solar activity.