bluuebunny/crossref_metadata_2025 huggingface dataset:
Early Buddhist Oral Transmission and the Problem of Accurate Source Monitoring
Authors: Anālayo Bhikkhu
Published: September 2020

A comparative study of two early Buddhist textual collections, theAṭṭhaka-vaggaand theUdāna, points to a process during which commentarial material gradually became part of the canonical text during oral transmission. This relates to the problem of inaccurate monitoring of the source from which a particular type of information stems, which can be related to the potential impact of mindfulness on the generation of false memories. Although the cultivation of mindfulness tends to strengthen various aspects of memory, its potential to empower the mind’s ability to associate can at times result in errors of memory or recognition. The overall picture that emerges in this way helps understand a pattern evident in early Buddhist oral texts, which reflect a concern with precise transmission but at the same time also show substantial additions of later material.
Geoelectrical investigation of groundwater potential and vulnerability of Oraifite, Anambra State, Nigeria
Authors: Eugene-Okorie Joy O. , Obiora Daniel N. , Ibuot Johnson C. , Ugbor Desmond O.
Published: September 2020

Electrical resistivity survey employing vertical electrical sounding was carried out in Oraifite, Southeastern Nigeria, involving a total of twenty soundings across, in order to assess the groundwater potential and the aquifer vulnerability in Oraifite. The field data were interpreted using the WINRESIST software, and the resulting geoelectric curves give the resistivities, depths and thicknesses of each geoelectrical layer. Dar Zarrouk parameters and aquifer transmissivity were computed using the values of aquifer resistivity and thickness. From the results, variations of the computed parameters were observed. Aquifer resistivity ranges from 420.1 to 27,585.8 Ωm having an average value of 4906.3 Ωm, while its thickness varies from 13.4 to 93. 9 m. Longitudinal conductance varies from 0.0015 to 0.2136 Ω−1, transverse resistance ranges from 29,388.88 to 1,158,604.0 Ωm2, while the transmissivity varies from 1.1692 to 123.7905m2/day. The contour maps reveal the distributions of these parameters, which help in delineating zones with different layer characteristics. The result from this study can be a reference for decision making in the abstraction and management of groundwater repositories.
Factors predicting survival in patients with locally advanced pancreatic cancer undergoing pancreatectomy with arterial resection
Authors: Napoli Niccolò , Kauffmann Emanuele , Cacace Concetta , Menonna Francesca , Caramella Davide , Cappelli Carla , Campani Daniela , Cacciato Insilla Andrea , Vasile Enrico , Vivaldi Caterina , Fornaro Lorenzo , Amorese Gabriella , Vistoli Fabio , Boggi Ugo
Published: September 2020

Pancreatectomy with arterial resection is a treatment option in selected patients with locally advanced pancreatic cancer. This study aimed to identify factors predicting cancer-specific survival in this patient population. A single-Institution prospective database was used. Pre-operative prognostic factors were identified and used to develop a prognostic score. Matching with pathologic parameters was used for internal validation. In a patient population with a median Ca 19.9 level of 19.8 U/mL(IQR: 7.1–77), cancer-specific survival was predicted by: metabolic deterioration of diabetes (OR = 0.22, p = 0.0012), platelet count (OR = 1.00; p = 0.0013), serum level of Ca 15.3 (OR = 1.01, p = 0.0018) and Ca 125 (OR = 1.02, p = 0.00000137), neutrophils-to-lymphocytes ratio (OR = 1.16; p = 0.00015), lymphocytes-to-monocytes ratio (OR = 0.88; p = 0.00233), platelets-to-lymphocytes ratio (OR = 0.99; p = 0.00118), and FOLFIRINOX neoadjuvant chemotherapy (OR = 0.57; p = 0.00144). A prognostic score was developed and three risk groups were identified. Harrell’s C-Index was 0.74. Median cancer-specific survival was 16.0 months (IQR: 12.3–28.2) for the high-risk group, 24.7 months (IQR: 17.6–33.4) for the intermediate-risk group, and 39.0 months (IQR: 22.7–NA) for the low-risk group (p = 0.0003). Matching the three risk groups against pathology parameters, N2 rate was 61.9, 42.1, and 23.8% (p = 0.04), median value of lymph-node ratio was 0.07 (IQR: 0.05–0.14), 0.04 (IQR:0.02–0.07), and 0.03 (IQR: 0.01–0.04) (p = 0.008), and mean value of logarithm odds of positive nodes was − 1.07 ± 0.5, − 1.3 ± 0.4, and − 1.4 ± 0.4 (p = 0.03), in the high-risk, intermediate-risk, and low-risk groups, respectively. An online calculator is available at www.survivalcalculator-lapdac-arterialresection.org. The prognostic factors identified in this study predict cancer-specific survival in patients with locally advanced pancreatic cancer and low Ca 19.9 levels undergoing pancreatectomy with arterial resection.
Effect of Heat Input on the Microstructural, Mechanical, and Corrosion Properties of Dissimilar Weldment of Conventional Austenitic Stainless Steel and Low-Nickel Stainless Steel
Authors: Tandon Vipin , Thombre Manish A. , Patil Awanikumar P. , Taiwade Ravindra V. , Vashishtha Himanshu
Published: September 2020

In the present investigation, an attempt has been made to investigate the replacement compatibility of conventional austenitic stainless steel (316L) with low-Ni austenitic stainless steel (201) by employing their dissimilar welding using gas tungsten arc welding technique with varying heat input. The effects of heat input on the microstructural, mechanical, and corrosion properties were studied. The result depicts the balanced austenite/ferrite content in the fusion zone for both the heat inputs. The low heat input process, which results in a faster cooling rate, demonstrates higher tensile strength and microhardness. Similarly, the pitting corrosion resistance of the fusion zone demonstrates better properties on the low heat input process attributed to the lesser dendritic length and lesser interdendritic arm spacing.
Older Women’s Perspectives Driving Mammography Screening Use and Overuse: a Narrative Review of Mixed-Methods Studies
Authors: Austin Jessica D. , Shelton Rachel C. , Lee Argov Erica J. , Tehranifar Parisa
Published: September 2020

Purpose of Review

Examining what older women know and perceive about mammography screening is critical for understanding patterns of under- and overuse, and concordance with screening mammography guidelines in the USA. This narrative review synthesizes qualitative and quantitative evidence around older women’s perspectives toward mammography screening.

Recent Findings

The majority of 43 identified studies focused on promoting mammography screening in women of different ages, with only four studies focusing on the overuse of mammography in women ≥ 70 years old. Older women hold positive attitudes around screening, perceive breast cancer as serious, believe the benefits outweigh the barriers, and are worried about undergoing treatment if diagnosed. Older women have limited knowledge of screening guidelines and potential harms of screening.

Efforts to address inequities in mammography access and underuse need to be supplemented by epidemiologic and interventional studies using mixed-methods approaches to improve awareness of benefits and harms of mammography screening in older racially and ethnically diverse women. As uncertainty around how best to approach mammography screening in older women remains, understanding women’s perspectives along with healthcare provider and system-level factors is critical for ensuring appropriate and equitable mammography screening use in older women.
Blended Treatment for Depressive Disorders in Youth: a Narrative Review
Authors: Rasing Sanne P. A.
Published: September 2020

Depressive disorders are the most prevalent mental health disorder in adolescents with detrimental consequences; effective and available treatment is crucial. Face-to-face and computerized treatments both have advantages but also downsides. Merging these two into one so-called blended treatment seems to be an optimal combination of elements. This current review addresses blended treatment for youth depression and aims to summarize existing knowledge on effectiveness as well as patients’ and therapists’ perspectives. Results showed promising significant decreases in symptoms, but no evidence for differences between blended and face-to-face treatment was found. Patients’ perspectives were mixed; they reported strong preferences for face-to-face treatment, but participants actually receiving blended treatment were mainly positive. Therapists’ attitudes were neutral, but they expressed their worries about the unknown risks on adverse events. Future research is needed and should, beside effectiveness and cost-effectiveness, pay close attention to the risks that are mentioned by therapists.
Finite Element Investigation of the Influence of SiC Particle Distribution on Diamond Cutting of SiCp/Al Composites
Authors: Lu Shijin , Li Zengqiang , Zhang Junjie , Zhang Jianguo , Wang Xiaohui , Yan Yongda , Sun Tao
Published: September 2020

Characteristics of internal microstructures have a strong impact on the properties of particulate reinforced metal composites. In the present work, we perform finite element simulations to elucidate fundamental mechanisms involved in the ultra-precision orthogonal cutting of aluminum-based silicon carbide composites (SiCp/Al), with an emphasis on the influence of particle distribution characteristic. The SiCp/Al composite with a particle volume fraction of 25 vol% and a mean particle size of 10 μm consists of randomly distributed polygon-shaped SiC particles, the elastic deformation and brittle failure of which are described by the brittle cracking model. Simulation results reveal that in addition to metal matrix tearing, cutting-induced particle deformation in terms of dislodging, debonding, and cracking plays an important role in the microscopic deformation and correlated machining force variation and machined surface integrity. It is found that the standard deviation of particle size to the mean value has a strong influence on the machinability of microscopic particle–tool edge interactions and macroscopically observed machining results. The present work provides a guideline for the rational synthesis of particulate-reinforced metal composites with high machinability.
Rapid Conversion of a Biomedical Engineering Laboratory from in Person to Online
Authors: Lancashire H. , Vanhoestenberghe A.
Published: September 2020

Temporary higher education institution closures in response to the 2020 COVID-19 pandemic disrupted student teaching. This paper reports on the rapid conversion of an in person laboratory session to online delivery, within 24 h of the previously scheduled in person session, and two working days after the end of face-to-face teaching at the authors’ institution. To ensure teaching continuity for students, and address intended learning outcomes (ILOs) where possible, we created online material rapidly in a manner familiar to students. Online material followed the same structure as a previously released laboratory script, intended for the in person session, and was presented on the institutional Virtual Learning Environment. The online material comprised experimental data in tables and equipment readouts, brief descriptions, and short videos demonstrating the experimental methods. We assess to what extent the ILOs were met, and argue that clear ILOs help guide changes to teaching methods, to reduce any disruption to student learning. Four aspects of the initiative are highlighted: rapid delivery; familiar structure; familiar delivery; and videos used for emphasis.
water/watery/watering: Concepts for Theorising in Environmental Education
Authors: Lasczik Alexandra , Rousell David , Ofosu-Asare Yaw , Foley Angela V. , Hotko Katie , Khatun Ferdousi , Paquette Marie-Laurence
Published: September 2020

The assemblage of water/watery/watering is a lively cartography of how water may be accounted for when theorising with and through environmental education research. Challenging the universalising claims of Western technoscience and the colonial logic of extraction, the article develops an alternative theoretical mapping of environmental education through engagements with Ingold’s (2007, 2012, 2015) concepts of lines, knots, and knotting. For this article and for the Special Issue in which it is housed, the concepts of such knottings are defined as an assemblage of haecceities, lived events that are looped, tethered and entangled as material and conceptual agencies that inhere within situated encounters. Thus, this article grapples with the need to account for water differently in contemporary posthuman ecologies. To overcome anthropocentric and mastery-oriented approaches, various other ways to account for water in science or environmental education will continue to come to the surface, bubbling and rushing like a waterfall as they have done in this work. Some of these will include thinking with water, which will be central to a theoretical mapping of water that seeks embrace sticky knots. The article explores a (re)turn to artful practices and encounters as spaces in which posthumanist concepts for environmental education might be cultivated.
The oldest bifoliate cystoporate and two other bryozoan taxa from the Dapingian (Middle Ordovician) of north-western Russia
Authors: Koromyslova Anna V. , Fedorov Petr V.
Published: September 2020

Bryozoans from the Dapingian (Middle Ordovician) of the Baltic paleobasin remain poorly studied and their taxonomic composition is unclear. In this paper, three bryozoan taxa, a bifoliate cystoporatePlanopora volkhovensisn. gen. n. sp., a trepostomeHemiphragma insolitumn. sp., and an esthonioporateEsthoniopora claraKoromyslova, are described from Dapingian deposits of an unusual clayey-calcareous Hecker-type mudmound on the right bank of the Volkhov River in Leningrad Oblast’, north-western Russia. Combined X-ray microtomography, scanning electron microscopy, and light microscopy of thin sections were used to characterize their morphology. Analysis of the stratigraphic distribution of early cystoporate bryozoans suggests thatPlanoporan. gen. is the oldest сystoporate bryozoan with an erect, bifoliate colony. The growth modes of these bryozoans are discussed. The colonies ofP.volkhovensisn. gen. n. sp. andE.clarahave an attachment structure, a holdfast, at their base, probably indicating their attachment to sponge spicules. The bryozoanH.insolitumn. sp. produced rod-like colonies, formed by overgrowing the problematic tubular fossilSphenothallusHall. It can be assumed that sponges with unfused siliceous spicules and individuals ofSphenothalluswere numerous on the surface of the mudmound during its formation and provided a suitable substrate for settlement of bryozoan larvae.

UUID:http://zoobank.org/5715872a-8c61-446e-9413-d713fdef1a08
Association between genetic and socioenvironmental risk for schizophrenia during upbringing in a UK longitudinal cohort
Authors: Newbury J. B. , Arseneault L. , Caspi A. , Moffitt T. E. , Odgers C. L. , Belsky D. W. , Sugden K. , Williams B. , Ambler A. P. , Matthews T. , Fisher H. L.
Published: September 2020

Background

Associations of socioenvironmental features like urbanicity and neighborhood deprivation with psychosis are well-established. An enduring question, however, is whether these associations are causal. Genetic confounding could occur due to downward mobility of individuals at high genetic risk for psychiatric problems into disadvantaged environments.

Methods

We examined correlations of five indices of genetic risk [polygenic risk scores (PRS) for schizophrenia and depression, maternal psychotic symptoms, family psychiatric history, and zygosity-based latent genetic risk] with multiple area-, neighborhood-, and family-level risks during upbringing. Data were from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally-representative cohort of 2232 British twins born in 1994–1995 and followed to age 18 (93% retention). Socioenvironmental risks included urbanicity, air pollution, neighborhood deprivation, neighborhood crime, neighborhood disorder, social cohesion, residential mobility, family poverty, and a cumulative environmental risk scale. At age 18, participants were privately interviewed about psychotic experiences.

Results

Higher genetic risk on all indices was associated with riskier environments during upbringing. For example, participants with higher schizophrenia PRS (OR = 1.19, 95% CI = 1.06–1.33), depression PRS (OR = 1.20, 95% CI = 1.08–1.34), family history (OR = 1.25, 95% CI = 1.11–1.40), and latent genetic risk (OR = 1.21, 95% CI = 1.07–1.38) had accumulated more socioenvironmental risks for schizophrenia by age 18. However, associations between socioenvironmental risks and psychotic experiences mostly remained significant after covariate adjustment for genetic risk.

Conclusion

Genetic risk is correlated with socioenvironmental risk for schizophrenia during upbringing, but the associations between socioenvironmental risk and adolescent psychotic experiences appear, at present, to exist above and beyond this gene-environment correlation.
The amyloid cascade hypothesis and Alzheimer’s disease: A mathematical model
Authors: BERTSCH M. , FRANCHI B. , MEACCI L. , PRIMICERIO M. , TESI M.C.
Published: September 2020

The paper presents a conceptual mathematical model for Alzheimer’s disease (AD). According to the so-called amyloid cascade hypothesis, we assume that the progression of AD is associated with the presence of soluble toxic oligomers of beta-amyloid. Monomers of this protein are produced normally throughout life, but a change in the metabolism may increase their total production and, through aggregation, ultimately results in a large quantity of highly toxic polymers. The evolution from monomeric amyloid produced by the neurons to senile plaques (long and insoluble polymeric amyloid chains) is modelled by a system of ordinary differential equations (ODEs), in the spirit of the Smoluchowski equation. The basic assumptions of the model are that, at the scale of suitably small representative elementary volumes (REVs) of the brain, the production of monomers depends on the average degradation of the neurons and in turn, at a much slower timescale, the degradation is caused by the number of toxic oligomers. To mimic prion-like diffusion of the disease in the brain, we introduce an interaction among adjacent REVs that can be assumed to be isotropic or to follow given preferential patterns. We display the results of numerical simulations which are obtained under some simplifying assumptions. For instance, the amyloid cascade is modelled by just three ordinary differential equations (ODEs), and the simulations refer to abstract 2D domains, simplifications which can be easily avoided at the price of some additional computational costs. Since the model is suitably flexible to incorporate other mechanisms and geometries, we believe that it can be generalised to describe more realistic situations.
Radiofrequency catheter ablation for supraventricular tachycardia in a paediatric population: characteristics of tachycardia mechanisms in a subpopulation with early onset
Authors: Schibli Yamina , Gass Matthias , Berger Florian , Balmer Christian
Published: September 2020

Background:

In children, the first episode of supraventricular tachycardia occurs at various ages. The aim of this study is to describe age-specific tachycardia mechanisms, clinical findings, and outcome in a contemporary cohort of paediatric patients with supraventricular tachycardia.

Methods:

Retrospective analysis of 531 consecutive patients with structurally normal hearts under the age of 18 years who underwent invasive electrophysiological study for supraventricular tachycardia. The study population was divided into two groups, early-onset group (n = 57) and late-onset group (n = 474), according to the age of the occurrence of the first tachycardia before or after the age of 12 months.

Results:

Accessory pathway-mediated tachycardia was more common (82.5 versus 50.1%, p < 0.001) and the proportion of left-sided accessory pathways was more pronounced (74.5 versus 53.7%, p = 0.01) in the early-onset group than in the late-onset group. The antegrade and retrograde refractory periods of the accessory pathways were similar in both groups, but pre-excitation was more common in the early-onset group (50.9 versus 31.9%, p = 0.007). Typical atrioventricular nodal re-entrant tachycardia was more common (36.7 versus 7.0%, p < 0.001) in the late-onset group. There was no difference among the two groups regarding overall outcome.

Conclusion:

Accessory pathway-mediated re-entrant tachycardia is the most common mechanism of recurrent supraventricular tachycardia in infants with structurally normal hearts who are later referred to an electrophysiological study. These pathways often cause pre-excitation and tend to be located on the left side whereas their refractory period is not different from that of patients with late-onset tachycardia.
Repair of anomalous right upper pulmonary venous connection with extracardiac tunnel using pedicled autologous pericardium
Authors: An Kang , Lv Xiaodong , Hua Zhongdong
Published: September 2020

We introduce a new surgical technique where an extracardiac tunnel is created using pedicled autologous pericardium in an 8-month-old boy who was diagnosed with ventricular septal defect and anomalous connection of the right superior pulmonary vein to the superior vena cava.
Characterisation and use of OSLD for in vivo dosimetry in head and neck intensity-modulated radiation therapy
Authors: Raj L. Jose Solomon , Pearlin Benedicta , Peace B. S. Timothy , Isiah Rajesh , Singh I. Rabi Raja
Published: September 2020

Aim:

This study reveals the characteristic nature and the use of optically stimulated luminescence dosimeters (OSLD) as an in vivo dosimetry tool for head and neck intensity-modulated radiation therapy (IMRT).

Materials and methods:

Calibration and characterisation of OSLD such as sensitivity, reproducibility, dose-rate dependence, beam quality dependence, output factor measurement and comparison of two bleaching techniques using halogen and compact fluorescent lamp (CFL) were initially performed. Later, eye dose measurements were performed for head and neck IMRT patients using OSLD and were compared with the corresponding dose calculated by the treatment planning system (TPS).

Results:

While the sensitivity was found to be within ±5%, the dose-rate dependence and reproducibility were found to be within ±3%. The OSLD showed an under-response of 3% for 15 MV and an increase in response by 5% for Co60 (1·25 MeV) when compared with the 6 MV X-ray beam. Therefore, a separate calibration for different beam energies is required. The percentage deviation of OSLD to that of TPS was found to be within ±2·77%. The OSLD has been successfully used for the in vivo dosimetry of patients who received IMRT. Hence, it is concluded that OSLDs can serve as effective dosimeters for in vivo dosimetry.
Bullous pemphigoid development during the course of breast cancer: a radiation induced or a radiation recall dermatitis?
Authors: Ben Rejeb Mouna , Moujahed Rim , Zehani Alia , Kochbati Lotfi
Published: September 2020

Background:

Bullous pemphigoid (BP) is the most common autoimmune bullous disease, which is usually seen in older ages. Rarely, radiotherapy (RT) has been reported as a localised trigger factor for BP.

Case:

We present a case of a 64-year-old woman who underwent radical mastectomy and radiation therapy for breast cancer. Two months after the completion of RT with adjuvant Trastuzumab, a BP eruption developed in the irradiated area, spreading thereafter to other skin areas. The patient was treated with oral corticosteroids and the lesions evolved favourably.

Conclusion:

This case demonstrates a relatively benign skin reaction that could develop during the course of cancer treatment, which required co-management by oncologists, pathologists and dermatologists.
Extended formulation in cognitive behavioural therapy for OCD: a single case experimental design
Authors: Chatburn Eleanor , Millar Josie , Ryan Joachim
Published: September 2020

The demanding nature of exposure work that forms an essential component of exposure and response prevention (ERP) for obsessive compulsive disorder (OCD) is for some patients intolerable and leads to disengagement. The addition of cognitive therapy to ERP (CBT) with a focus on developing a shared understanding of how OCD works may aid engagement. This paper reports a case study of an individual who had not responded to two previous courses of ERP due to engagement difficulties with the treatment rationale. This study aimed to establish if CBT for OCD, incorporating an extended period of assessment and longitudinal formulation, would: (1) aid in engagement with the treatment rationale and therapy and (2) lead to an improvement in OCD symptoms, general functioning and mood. An A–B single case experimental design was used. Standardised measures were collected at weekly intervals over 15 sessions of CBT, in conjunction with pre–post idiographic behavioural measures. The extended formulation was successful in helping the individual to develop a less threatening understanding of how OCD works, enabling her to engage in therapy. This led to a reduction in the duration of the overt compulsions in her behavioural measures although on the standardised measures there was no change in self-reported OCD symptoms. The patient’s covert rituals and underlying responsibility and control beliefs largely remained intact, thus maintaining her OCD and requiring further intervention. There was a significant improvement in social functioning and consequently the patient reported being able to regain a sense of some control in her life.

Key learning aims

(1)

To describe the factors that might lead to a patient disengaging from exposure work in treatment for OCD.

(2)

To identify the advantages and disadvantages of incorporating a period of extended formulation when working with patients who have not previously been able to tolerate exposure work.

(3)

To describe ways of monitoring observable improvements in areas of functioning that matter to the patient in order to help them to celebrate their progress and boost their sense of self-efficacy.
Wave Dissipation by Bottom Friction on the Inner Shelf of a Rocky Shore
Authors: Gon Casey J. , MacMahan Jamie H. , Thornton Edward B. , Denny Mark
Published: September 2020

Approximately 32% of the measured wave energy flux by sea and swell waves was dissipated over distances less than 130 m, outside of wave breaking on the inner shelf, over a rocky shore in southern Monterey Bay, CA. The bottom roughness of the rocky shore is defined by the standard deviation of bottom vertical variability, σb, that is 0.9 m, which is of similar magnitude to previously measured σb for rough coral reefs. Spectral wave energy flux balanced by bottom friction is modeled and compared with observations. Measured average wave reflection was 0.08 and is neglected in the model. The average energy dissipation owing to bottom friction over the rocky shore results in energy friction factors, fe, ranging 4 to 34. The observed fe are larger than previously measured fe on coral reefs. An empirical power law relationship is developed for fe as a function of the ratio of wave orbital excursion amplitude, Ab, and σb, based on combined data from coral reefs, rocky platforms, and this rocky shore. As σb increases, fe increases. Numerical simulation by Yu et al. (2018, https://doi.org/10.9753/icce.v36.waves.57) of waves over large bottom variations, similar to observed on coral reefs, suggests that drag forces do not account for the large observed fe. Therefore, it is hypothesized that bottom friction on rocky shores is a function of multiscale physical and biological roughness.
Can Exploratory Modeling of Water Scarcity Vulnerabilities and Robustness Be Scenario Neutral?
Authors: Quinn J. D. , Hadjimichael A. , Reed P. M. , Steinschneider S.
Published: September 2020

Planning under deep uncertainty, when probabilistic characterizations of the future are unknown, is a major challenge in water resources management. Many planning frameworks advocate for “scenario‐neutral” analyses in which alternative policies are evaluated over plausible future scenarios with no assessment of their likelihoods. Instead, these frameworks use sensitivity analysis to discover which uncertain factors have the greatest influence on performance. This knowledge can be used to design monitoring programs and adaptive policies that respond to changes in the critical uncertainties. However, scenario‐neutral analyses make implicit assumptions about the range and independence of the uncertain factors that may not be consistent with the coupled human‐hydrologic processes influencing the system. These assumptions could influence which factors are found to be most important and which policies are most robust, belying their neutrality; assuming uniformity and independence could have decision‐relevant implications. This study illustrates these implications using a multistakeholder planning problem within the Colorado River Basin, where hundreds of rights holders vie for the river's limited water under the law of prior appropriation. Variance‐based sensitivity analyses are performed to assess users' vulnerabilities to changing hydrologic conditions using four experimental designs: (1) scenario‐neutral samples of hydrologic factors, centered on recent historical conditions, (2) scenarios informed by climate projections, (3) scenarios informed by paleohydrologic reconstructions, and (4) scenario‐neutral samples of hydrologic factors spanning all previous experimental designs. Differences in sensitivities and user robustness rankings across the experiments illustrate the challenges of inferring the most consequential drivers of vulnerabilities to design effective monitoring programs and robust management policies.
Interacting Infrastructure Disruptions Due to Environmental Events and Long‐Term Climate Change
Authors: Hummel Michelle A. , Tcheukam Siwe Alain , Chow Aaron , Stacey Mark T. , Madanat Samer M.
Published: September 2020

Climate change places additional stress on critical infrastructure systems as demand for resources (e.g., water and electricity) increases and environmental disruptions (e.g., flooding and wildfires) become more frequent and severe. Interconnected infrastructure systems may be particularly vulnerable, as disruptions in one system can cascade to other systems and increase the severity of impacts. To ensure continued functionality, infrastructure systems must be designed or adapted to account for changing environmental conditions, with consideration for the interactions between systems. For this study, we examine the dependencies between shoreline protective infrastructure and transportation infrastructure in the context of sea level rise in the San Francisco Bay Area. Shoreline modifications implemented in one location can cause hydrodynamic feedbacks that exacerbate flooding and associated disruptions elsewhere. On the other hand, the decision not to implement shoreline protection can cause local flooding of roadways that leads to traffic feedbacks and system‐wide travel delays. We compare the magnitude of these feedbacks, in terms of vehicle hours traveled (VHT), across a range of county‐level shoreline scenarios to characterize the effects of one county's shoreline adaptation decisions on its neighbors. Our results show that VHT increases by as much as 7.2% due to hydrodynamic feedbacks and 10.7% due to traffic feedbacks. Comparing these effects for each scenario allows for targeted decision‐making about adaptation approaches that account for both the local effects of flood disruptions and the regional network effects driven by infrastructure interactions.
Thermal and Compositional Anomalies of the Australian Upper Mantle From Seismic and Gravity Data
Authors: Tesauro Magdala , Kaban Mikhail K. , Aitken Alan R. A.
Published: September 2020

To discern temperature and compositional variations of the Australian upper mantle, we apply an integrative technique, which jointly interprets seismic tomography and gravity data. The final thermal model, obtained by changing the upper mantle composition according to the density variations, shows temperatures higher by 100–150°C in the Archean and Proterozoic upper mantle, with respect to the initial model based on a uniform “fertile” composition. In the North and West Australian cratons, the upper mantle is cold, with composition depleted in heavy constituents. This suggests the presence of an Archean lithosphere, which remained relatively undisturbed through the Proterozoic. Central Australia is predominantly characterized by a thick, low‐temperature lithosphere having a more fertile composition. Its shallow part is characterized by a thin layer of low‐velocity mantle, which is interpreted by our results as a thermal anomaly. However, this high‐temperature anomaly is hard to reconcile with the tectonic history of the region. A low‐density mineral phase, such as amphibole, may reduce the density relative to our assumed composition. Furthermore, we observe larger iron depletion in the Western Australian Craton than in the Proterozoic terranes. At the depths larger than 150 km, the depletion becomes negligible beneath the Proterozoic regions, while it also persists in the Western Australian Craton at the depths larger than 200 km.
COVID‐19 Impact on the Concentration and Composition of Submicron Particulate Matter in a Typical City of Northwest China
Authors: Xu Jianzhong , Ge Xinlei , Zhang Xinghua , Zhao Wenhui , Zhang Ruixiong , Zhang Yuzhong
Published: September 2020

In this study, we evaluated the variations of air quality in Lanzhou, a typical city in Northwestern China impacted by the COVID‐19 lockdown. The mass concentration and chemical composition of non‐refractory submicron particulate matter (NR‐PM1) were determined by a high‐resolution aerosol mass spectrometer during January‐March 2020. The concentration of NR‐PM1 dropped by 50% from before to during control period. The five aerosol components (sulfate, nitrate, ammonium, chloride, and organic aerosol [OA]) all decreased during the control period with the biggest decrease observed for secondary inorganic species (70% of the total reduction). Though the mass concentration of OA decreased during the control period, its source emissions varied differently. OA from coal and biomass burning remained stable from before to during control period, while traffic and cooking related emissions were reduced by 25% and 50%, respectively. The low concentration during the control period was attributed to the lower production rate for secondary aerosols.
Suprathermal Electron Evolution Under the Competition Between Plasmaspheric Plume Hiss Wave Heating and Collisional Cooling
Authors: Wang Zhongshan , Su Zhenpeng , Liu Nigang , Dai Guyue , Zheng Huinan , Wang Yuming , Wang Shui
Published: September 2020

Suprathermal electrons are a major heat source of ionospheric plasma. How the suprathermal electrons evolve during their bounces inside the plasmasphere is a fundamental question for the magnetosphere‐ionosphere coupling. On the basis of Van Allen Probes observations and quasi‐linear simulations, we present here the first quantitative study on the evolution of suprathermal electrons under the competition between Landau heating by whistler mode hiss waves and Coulomb collisional cooling by background plasma inside a plasmaspheric plume. We show that the Landau heating can prevail over the collisional cooling for >50 eV electrons and cause the field‐aligned suprathermal electron fluxes to increase by up to 1 order of magnitude within 1.5 hr. Our results imply that the plasmaspheric plume hiss waves could mediate energy from the ring current electrons to the ionospheric plasma.
Seasonal Effect on Hemispheric Asymmetry in Ionospheric Horizontal and Field‐Aligned Currents
Authors: Workayehu A. B. , Vanhamäki H. , Aikio A. T.
Published: September 2020

We present a statistical investigation of the seasonal effect on hemispheric asymmetry in the auroral currents during low (Kp < 2) and high (Kp ≥ 2) geomagnetic activity. Five years of magnetic data from the Swarm satellites has been analyzed by applying the spherical elementary current system (SECS) method. Bootstrap resampling has been used to remove the seasonal differences between the hemispheres in the data set. In general, the currents are larger in the Northern Hemisphere (NH) than in the Southern Hemisphere (SH). Asymmetry is larger during low than high Kp and during local winter and local autumn than local summer and local spring. For all Kp conditions together, the NH/SH ratio for FACs in winter, autumn, spring, and summer are 1.17 ± 0.05, 1.14 ± 0.05, 1.07 ± 0.04, and 1.02 ± 0.04, respectively. The largest asymmetry is observed during low Kp in local winter, when the excess in the NH currents is 21 ± 5% in FAC, 14 ± 3% in curl‐free (CF) and 10 ± 3% in divergence‐free (DF) current. We also find that evening sector (13–24 MLT) contributes more to the high NH/SH ratio than the morning (01–12 MLT) sector. The physical mechanisms producing the hemispheric asymmetry are not presently understood. We calculated the solar‐induced ionospheric conductances during low Kp conditions from the IRI model. The model conductance NH/SH ratios are above 1 in autumn and spring, similar to the currents, but below 1 for winter, which is in contradiction with the currents. Therefore, we do not consider solar‐induced conductances as the main explanation for hemispheric asymmetry.
Evaluation of Shipboard and Satellite‐Derived Bathymetry and Gravity Data Over Seamounts in the Northwest Pacific Ocean
Authors: Watts A. B. , Tozer B. , Harper H. , Boston B. , Shillington D. J. , Dunn R.
Published: September 2020

Earth's surface topography/bathymetry and gravity fields provide important constraints on crustal structure and the tectonic processes that act on it due, for example, to plate flexure and mantle convection. Such studies require, however, high accuracy measurements at a wide range of spatial scales. During the past few decades much progress has been made in the acquisition of bathymetry and gravity data using both shipboard and satellite altimeter methods. Surprisingly, there have been few comparisons of these data. During April–June, 2019 we had the opportunity onboard a R/V Marcus G. Langseth cruise in the northwest Pacific Ocean to compare data acquired with an EM122 Kongsberg swath bathymetry system and a refurbished Bell Aerospace BGM‐3 gravimeter with the most recent global bathymetry and gravity fields. We find that while the recovery of bathymetry and gravity from satellite radar altimeter data in areas of sparse shipboard data has been impressive, root mean square discrepancies in the range 175.5–303.4 m and 2.6–6.3 mGal exist between shipboard and satellite‐derived data. While these discrepancies are small, they are highly correlated and therefore have implications for the density structure, rock type and geological processes occurring on the deep seafloor. Shipboard data should continue to be acquired, especially over features such as seamounts, banks, and ridges that are associated with short wavelength (<25 km wavelength) bathymetric and gravimetric features beyond that is recoverable in satellite‐derived data.
Exploring Sources of Uncertainty in Steric Sea‐Level Change Estimates
Authors: Camargo Carolina M. L. , Riva Riccardo E. M. , Hermans Tim H. J. , Slangen Aimée B. A.
Published: September 2020

Recent studies disagree about the contribution of variations in temperature and salinity of the oceans—steric change—to the observed sea‐level change. This article explores two sources of uncertainty to both global mean and regional steric sea‐level trends. First, we analyze the influence of different temperature and salinity data sets on the estimated steric sea‐level change. Next, we investigate the impact of different stochastic noise models on the estimation of trends and their uncertainties. By varying both the data sets and noise models, the global mean steric sea‐level trend and uncertainty can vary from 0.69 to 2.40 and 0.02 to 1.56 mm/year, respectively, for 1993–2017. This range is even larger on regional scales, reaching up to 30 mm/year. Our results show that a first‐order autoregressive model is the most appropriate choice to describe the residual behavior of the ensemble mean of all data sets for the global mean steric sea‐level change over the last 25 years, which consequently leads to the most representative uncertainty. Using the ensemble mean and the first‐order autoregressive noise model, we find a global mean steric sea‐level change of 1.36 ± 0.10 mm/year for 1993–2017 and 1.08 ± 0.07 mm/year for 2005–2015. Regionally, a combination of different noise models is the best descriptor of the steric sea‐level change and its uncertainty. The spatial coherence in the noise model preference indicates clusters that may be best suited to investigate the regional sea‐level budget.
Robust Acceleration of Stratospheric Moistening and Its Radiative Feedback Under Greenhouse Warming
Authors: Xia Yan , Huang Yi , Hu Yongyun
Published: September 2020

Stratospheric water vapor (SWV) changes, in response to increasing CO2, as a feedback component may play an important role in the Earth's energy budget. It has drawn extensive studies in the past decade. Here, we calculate the SWV climate feedback using the 150‐year CO2 forcing (1pctCO2) simulations in the CMIP6 ensemble of models. All models robustly show a moistening of the stratosphere, causing a positive radiative feedback to surface warming. We find that the stratospheric moistening rate and the SWV feedback both increase with surface warming. The moistening occurs at a rate of 0.9 ± 0.1 ppmv K−1 and its radiative feedback measured by the fixed dynamical heating method is 0.11 ± 0.02 W m−2 K−1 in the first 50 model years; the moistening rate increases to 1.2 ± 0.2 ppmv K−1 and the feedback increases to 0.16 ± 0.03 W m−2 K−1 in the last 50 model years when the global‐mean surface temperature is 3.3 K warmer. These increases are found to be caused by an amplified rate of tropical tropopause warming with respect to surface warming, which is 0.6 and 1.1 K K−1 for the two 50‐year periods, respectively. We conclude that the SWV feedback is strengthening with surface warming, which can contribute to increasing climate sensitivity in the future under global warming.
Production and Transport of Supraglacial Debris: Insights From Cosmogenic 10Be and Numerical Modeling, Chhota Shigri Glacier, Indian Himalaya
Authors: Scherler D. , Egholm D. L.
Published: September 2020

Many mountain glaciers carry some amount of rocky debris on them, which modifies surface ablation rates. The debris is typically derived from erosion of the surrounding topography and its supraglacial extent is predominantly controlled by the relative accumulation rates of debris versus snow. Because Global Warming results in shrinking glaciers as well as thawing permafrost worldwide, changes in both rates will most likely affect the evolution of supraglacial debris cover and thus the response of glaciers to climate change. Here we report 10Be concentrations measured in five amalgamated debris samples collected from the main medial moraine of the Chhota Shigri Glacier, India. Results suggest headwall erosion rates that are ~0.5–1 mm year−1, and apparently increasing (10Be concentrations are decreasing) toward the present. We employed a numerical ice flow model that we combined with a new Lagrangian particle tracing routine to explore the impact of spatial and temporal variability in erosion rates and source areas on 10Be concentrations in the medial moraine. Our modeling results show that neither changes in source areas, related to the transient response of the glacier to ongoing climate change, nor four different scenarios of spatial and temporal variability in erosion rates could explain the observed trend in 10Be concentrations. Although not accounted for in our modeling explicitly, we suggest that the observed trend could be due to transiently enhanced erosion of recently deglaciated areas, or to greater spatial variability in erosion rates than explored in our models.
Deflating the LLSVPs: Bundles of Mantle Thermochemical Plumes Rather Than Thick Stagnant “Piles”
Authors: Davaille Anne , Romanowicz Barbara
Published: September 2020

Based on SEMUCB‐WM1 tomographic model, validated by other recent models, and fluid mechanics constraints, we show that the large low shear velocity provinces (LLSVPs) present at the base of the Earth's mantle beneath the Pacific and Africa do not extend as compact, uniform structures very high above the core‐mantle boundary. In contrast, they contain a number of well‐separated, low‐velocity conduits that extend vertically throughout most of the lower mantle. The conceptual model of compact piles, continuously covering the areal extent of the LLSVPs, is therefore not correct. Instead, each LLSVP is composed of a bundle of thermochemical upwellings probably enriched in denser than average material. It is only when the tomographic model is filtered to long wavelengths that the two bundles of plumes appear as uniform provinces. Furthermore, the overall shape of the LLSVPs is probably controlled by the distribution of subducted slabs, and due to their thermochemical nature, the position of both LLSVPs and individual upwelling dynamics should be time dependent. There is also evidence for smaller plumes originating near the CMB in the faster than average regions of the voting map of Lekic et al. (2012, https://doi.org/10.1016/j.epsl.2012.09.014) as well as other, barely resolved, weaker plumes within the LLSVPs. These finer‐scale features are starting to be resolved tomographically owing to improvements in full waveform modeling of body waves, including diffracted S waves (Sdiff) and waves multiply reflected on the core‐mantle boundary (ScS) and their codas.
Characterization and Quantification of Pore Water in Clays During Drying Process With Low‐Field NMR
Authors: Tian H. H. , Wei C. F.
Published: September 2020

Water transport in large‐specific surface soil is controlled by soil microstructure and soil‐water interaction. In this paper, soil‐water interaction and confined water dynamics as well as soil microstructure are studied by combining the nuclear magnetic resonance technique and the mercury intrusion porosimetry. It is revealed that during a drying process pore water drainage occurs sequentially from larger pores to smaller pores, and surface interaction parameter ρ1 appears to be a well‐defined quantity at a water content above one water layer, below which ρ1 shows a different trend. With the two‐dimensional T1‐T2 correlation measurements, surface dynamical parameters, including residence time and surface affinity coefficient, are determined, showing that the mobility of pore water decreases gradually with the decrease in water potential. The effect of temperature on the soil‐water interaction is discussed via the variation of relaxation time with temperature. The increase in residence time and surface affinity coefficient as well as effective activation energy ΔE indicates that the mobility of pore water decreases with the decrease in water potential. In addition, the positiveness of ΔE indicates that unsaturated hydraulic conductivity of clay increases with temperature, and a larger ΔE implies that the unsaturated hydraulic conductivity for the sample equilibrated at smaller potential is more sensitive to the temperature. The average pore sizes of the saturated samples are also determined by the mercury intrusion porosimetry, showing clear consistency between the mercury intrusion porosimetry (MIP) and nuclear magnetic resonance (NMR) measurements.