bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of echocardiography for diagnosis and prognostic stratification in hypertrophic cardiomyopathy
Authors: Mandeş Leonard , Roşca Monica , Ciupercă Daniela , Popescu Bogdan A.
Published: April 2020

Hypertrophic cardiomyopathy (HCM) is the most frequent cardiac disease with genetic substrate, affecting about 0.2–0.5% of the population. While most of the patients with HCM have a relatively good prognosis, some are at increased risk of adverse events. Identifying such patients at risk is important for optimal treatment and follow-up. While clinical and electrocardiographic information plays an important role, echocardiography remains the cornerstone in assessing patients with HCM. In this review, we discuss the role of echocardiography in diagnosing HCM, the key features that differentiate HCM from other diseases and the use of echocardiography for risk stratification in this setting (risk of sudden cardiac death, heart failure, atrial fibrillation and stroke). The use of modern echocardiographic techniques (deformation imaging, 3D echocardiography) refines the diagnosis and prognostic assessment of patients with HCM. The echocardiographic data need to be integrated with clinical data and other information, including cardiac magnetic resonance, especially in challenging cases or when there is incomplete information, for the optimal management of these patients.
WNT1, a target of miR-34a, promotes cervical squamous cell carcinoma proliferation and invasion by induction of an E-P cadherin switch via the WNT/β-catenin pathway
Authors: Li Baohua , Guo Xuedong , Li Na , Chen Qin , Shen Junhua , Huang Xiaoxiu , Huang Genping , Wang Fenfen
Published: April 2020

Purpose

Persistent infection with high-risk human papillomavirus (HR-HPV) is thought to play a prominent role in the initiation and progression of almost all cases of cervical cancer. Previously, we and others found that microRNA 34a (miR-34a) may be regulated by HR-HPV E6 to contribute to the development of cervical cancer. Here, we aimed to identify the oncogenic potential and clinical significance of a known miR-34a target, WNT1, in cervical squamous cell carcinoma (SCC) development and to investigate the associated mechanisms underlying cervical SCC cell proliferation and invasion.

Methods

WNT1 and miR-34a expression levels were assessed in primary cervical lesions using immunohistochemistry and qRT-PCR, respectively. The cellular effects and the expression of its associated genes were examined in cervical SCC-derived Siha and Caski cells after siRNA-WNT1 (downregulation) or miR-34a mimic (upregulation) treatment. A cervical SCC xenograft mouse model was used to investigate the in vivo effects of miR-34a overexpression. HPV-16 E6/E7 expression was inhibited by gene promoter siRNA targeting, after which the levels of miR-34a and WNT1 were examined.

Results

WNT1 protein upregulation was found to be associated with a poor prognosis in cervical SCC patients. In vitro assays in Siha and Caski cells revealed that WNT1 downregulation decreased cell proliferation and invasion, inhibited WNT/β-catenin activation and affected the expression of E-cadherin and P-cadherin. MiR-34a upregulation resulted in decreased WNT1 expression. An inverse correlation between miR-34a and WNT1 expression was also observed in primary cervical SCC tissues. In addition, we found that MiR-34a could regulate an E-cadherin to P-cadherin switch (E-P cadherin switch) to inhibit cell proliferation and tumorigenesis in vitro and in vivo via inactivation of the WNT1/β-catenin pathway. Finally, we found that decreased HPV-16 E6/E7 expression resulted in miR-34a upregulation and WNT1 downregulation in Siha and Caski cells.

Conclusions

From our results we conclude that WNT1, as a target of miR-34a, can promote cervical SCC cell proliferation and invasion by induction of an E-P cadherin switch via the WNT1/β-catenin pathway. Our results may provide new options for the treatment of patients with cervical SCC.
Teaching health professionals how to tailor gender-affirming medicine protocols: A design thinking project
Authors: MacKinnon Kinnon R. , Ross Lori E. , Gualdron David Rojas , Ng Stella L.
Published: April 2020

Background Content knowledge surrounding transgender (trans) medicine is currently lacking in the formal medical education curricula. Evidence indicates that the main protocols used to assess and refer trans patients for gender-affirming medicine are misunderstood by health professionals, and require flexible adaptation to achieve health equity and patient-centred care.
Approach A free online educational tool for gender-affirming medicine, The Path to Patient-Centred Care, was developed to teach learners how to adapt assessment protocols. Resource creation was supported by a knowledge translation grant that endorsed design thinking, a human-centred and solutions-focused framework recommended for use in curriculum development.
Evaluation The Path to Patient-Centred Care provides learners with information related to key principles of patient-centred care in gender-affirming medicine, including a guide on how to adapt the main assessment protocols to achieve equitable care. The curriculum also includes narratives from trans patients and health professionals that focus on health equity, and a clinical vignette about a complex case, designed to foster critical thinking on medical ethics. Project future directions involve an implementation and evaluation pilot study with a diverse group of continuing professional development medical learners using a mixed-methods program evaluation design.
Reflection The use of design thinking to develop this resource exemplifies a novel approach to curriculum development. By using pedagogical strategies that foster critical reflection, this innovative online education tool strives to teach self-directed learners how to provide care that emphasizes trans people’s self-determination and autonomy in medical decision-making.
Gestaltungsdimensionen der Kommunikation von automatisierten Fahrzeugen und anderen Verkehrsteilnehmenden
Authors: Joisten Philip , Freund Anton , Abendroth Bettina
Published: April 2020

Bereits heute wird die Kommunikation zwischen automatisierten Fahrzeugen und anderen Straßenverkehrsteilnehmenden entwickelt und erforscht, um zukünftig einen sicheren und effizienten Straßenverkehrsfluss zu gewährleisten. Dieser Beitrag zielt darauf ab, Gestaltungsdimensionen der Kommunikation zwischen automatisierten Fahrzeugen und anderen Straßenverkehrsteilnehmenden herzuleiten und zu analysieren. Folgende Fragestellung steht im Vordergrund: Wie kann eine Kommunikationsstrategie zwischen automatisierten Fahrzeugen und anderen Straßenverkehrsteilnehmenden gestaltet werden? Zur Beantwortung dieser Fragestellung werden Gestaltungsdimensionen theoretisch abgeleitet und eine Befragung (N = 30) und Beobachtung (N = 308) von Fußgänger/-innen in Testfeldern von automatisierten Bussen durchgeführt. Aufbauend auf Erkenntnissen der Kommunikationstheorie werden sechs Gestaltungsdimensionen (Wer, Warum, In welcher Situation, Was, Wann, Wie) und dahinterstehende zentrale Fragestellungen identifiziert. Die Ergebnisse der empirischen Studien zeigen Verhaltensweisen und den Kommunikationsbedarf von Fußgänger/-innen bei der Interaktion mit automatisierten Bussen. Die Analyse anhand der Gestaltungsdimensionen legt weiteren Forschungsbedarf offen, wie z. B. nach den zukünftigen Rollen aller Beteiligten im Straßenverkehr.

Praktische RelevanzDie Anwendung des Frameworks von Gestaltungsdimensionen unterstützt bei der Gestaltung der Kommunikation von automatisierten Fahrzeugen, um zukünftig die notwendige Kooperation zwischen Straßenverkehrsteilnehmenden sicherzustellen.
Effects of pylon geometry on mixing enhancement in a scramjet pylon-cavity flameholder
Authors: Oamjee A. , Sadanandan R.
Published: April 2020

Numerical investigation of the effect of pylon geometry within a pylon-cavity aided Supersonic Combustion Ramjet (SCRAMJET) combustor on mixing enhancement, flame-holding capability, fuel jet penetration and total pressure loss are conducted in the current study. RANS equations for compressed real gas are solved by coupled, implicit, second-order upwind solver. A two-equation SST model is used for turbulence modelling. Validation of the computational model is performed with the help of experimental data collected using surface pressure taps, Schlieren flow visualisation and particle image velocimetry (PIV). The study uses four distinct pylon geometry cases, which include the baseline geometry. Sonic injection of hydrogen fuel through a 1mm diameter hole at 2mm downstream of the pylon rear face along the axis of the test section floor is performed for every case. A crossflow of Mach number 2.2 at four bar absolute pressure and standard atmospheric temperature is maintained. A comparative study of mixing efficiency, total pressure loss, fuel jet penetration and fuel plume area fraction for the different cases evaluate the mixing performance. The simulations show that the Pylon 2 case gives a significant improvement in the performance parameters compared to the other geometries. It is observed that mixing efficiency and fuel jet penetration capability of the system are highly dependent on the streamwise vortex within the flameholder.
International Transformative Constitutionalism in Latin America
Authors: von Bogdandy Armin , Urueña René
Published: April 2020

This Article analyzes the rise of international transformative constitutionalism in Latin America and responds to some of the challenges to its legitimacy and effectiveness. It focuses on the practice of the Inter-American Court of Human Rights (IACtHR), the decisions and procedures of which constitute a small, but vibrant and essential, part of a wider Latin American community of human rights—a diverse group of actors who confront violence, social exclusion, and weak institutions through legal means.
Pandemic March: 2019 Coronavirus Disease’s First Wave Circumnavigates the Globe
Authors: Shultz James M. , Perlin Alanna , Saltzman Russell Gary , Espinel Zelde , Galea Sandro
Published: April 2020

Objective:

March 2020 was a pivotal month for the worldwide geographic and numeric expansion of the first wave of Coronavirus Disease 2019 (COVID-19). We examined the major storylines that depicted this explosive spread of COVID-19 around the globe.

Methods:

A detailed review of World Health Organization (WHO) situation reports, surveillance summaries, and online resources allowed us to quantify the increases in cases and deaths by region and by country throughout the month of March 2020.

Results:

During March, COVID-19 was officially declared by the WHO to be a pandemic. COVID-19 emerged from a focalized outbreak in the Western Pacific Region and rapidly proliferated across all continents worldwide. Globally, cumulative numbers of confirmed cases increased by a factor of nine throughout the month. During the entire month, cases rose exponentially throughout Europe. Starting in mid-March, confirmed cases accelerated coast-to-coast throughout the United States and, on March 26, the United States surpassed all other nations to rank first in numbers of cases. COVID-19 mortality lagged several weeks behind but by month’s end, death tolls were also rising exponentially.

Conclusion:

March 2020 was a consequential month when the COVID-19 pandemic wrapped completely around the planet, with outbreaks erupting in most nations worldwide.
Ordering the land beyond the Sixth Cataract: Imperial policy, archaeology and the role of Henry Wellcome
Authors: Vella Gregory Isabelle
Published: April 2020

The Sudan occupies a fairly complex place in archaeological enquiry. This is not a result of the archaeological record, rather it is due to a particular perception of the Sudan, its archaeology and history. The first excavators were archaeologists and anatomists who either worked in Egypt or in the Mediterranean, while the Anglo-Egyptian Condominium encouraged white-only scholars to both conduct research and to be active members of the newly formed political service in order to ‘know the natives’. In other words, archaeology from the outset was intimately connected to a particular political narrative and aim. This paper traces the historical context from the early 20th century to the development of archaeology south of beyond the Sixth Cataract south of the present-day capital of Khartoum, showing how it was created by Henry Wellcome. In particular, it focuses on the vast mortuary and habitation site of Jebel Moya, south-central Sudan, where new fieldwork is yielding fruitful results. Henry Wellcome's contribution to archaeology remains under-acknowledged. This long-overdue critical assessment traces and contextualizes the historical trajectories at play and situates them within the broader historical archaeology context.
Late-glacial fluctuations of two southern Patagonia outlet glaciers revealed by high-resolution seismic surveys
Authors: Lodolo Emanuele , Lozano Jorge , Donda Federica , Bran Donald , Baradello Luca , Tassone Alejandro , Romeo Roberto , Paterlini Marcelo , Grossi Maurizio , Caffau Mauro , Vilas Juan Francisco
Published: April 2020

Lago Argentino hosts various calving glaciers, among them the famous Perito Moreno. Whereas the onland late Pleistocene–Holocene glacial history is rather well constrained, the submerged glacier-related features were until now undisclosed. Here we present a series of high-resolution seismic profiles revealing moraine bodies associated with the late-glacial glacier dynamics and the first bathymetric map of the Brazo Rico and Brazo Sur, the two southern arms of Lago Argentino. At the eastern termination of Brazo Rico, we identified at the lake floor the submerged expression of the Puerto Bandera 3 moraine mapped onshore, which represents the oldest event (12,660 ± 70 cal yr BP oldest minimum age) recognized in this lake arm, and seven other younger events expressed by a series of terminal and recessional moraines. Along the Brazo Sur, few moraine bodies have been imaged by seismic data. Here, the youngest temporal constraint comes from the Frías moraine (ca. 6000 cal yr BP), which closes off the southern end of the Brazo Sur. At the confluence of the two arms, the Perito Moreno and the former Frías glacier merged and flowed toward east during their late-glacial maximum advance (i.e., Puerto Bandera 1 moraine). The subaqueous evidence of moraine bodies testifies to the occurrence of previously undocumented pulses of the Perito Moreno and former Frías glaciers within the general phase of late Pleistocene–Holocene regression.
THE EURO–ARAB INVESTMENT TREATY THAT NEARLY WAS
Authors: Denza Eileen , Poulsen Lauge N. Skovgaard
Published: April 2020

This article documents how members of the European Economic Community and members of the Arab League negotiated a draft ‘mega-regional’ investment protection treaty from 1976 to the late 1980s—the first of its kind. The negotiations produced a full draft treaty and came tantalisingly close to completion but ultimately ran into the political sands. Had it been concluded, the Convention would have been the most significant investment protection treaty ever negotiated at the time, and one of the most significant to this day. Negotiations were conducted within the cloak of diplomatic confidentiality, however, so the effort has remained unknown to even specialised scholars and practitioners to this day.
The Living Standards Capabilities for Elders scale (LSCAPE): adaptation and validation in a sample of Spanish seniors
Authors: Alhambra-Borrás Tamara , Doñate-Martínez Ascensión , Garcés-Ferrer Jorge
Published: April 2020

Living standards capabilities are an important determinant of healthy ageing. The Living Standards Capabilities for Elders scale (LSCAPE) is the main instrument available to assess living standards capabilities among older adults based on Sen's Capability Approach. The objectives of this study were: (a) to adapt and validate LSCAPE for use in the Spanish population; (b) to examine the dimensionality, validity and reliability; and (c) to establish the convergent validity of LSCAPE using self-reported measures of quality of life and income. The LSCAPE was administered to 441 Spanish seniors aged 65 and over. Confirmatory Factor Analysis (CFA) was used to analyse the dimensionality, validity and reliability. Discriminant and convergent validity of the model were assessed using Average Variance Extracted (AVE). Reliability was shown by Composite Reliability (CR) and Cronbach's alpha. Convergent validity was tested by correlating the LSCAPE scales and sub-scales with the Short-form Health Survey (SF-12) sub-scales. CFA showed that the LSCAPE Six-factor Model fits well to the data, showing Standardised Root Mean Square Residual < 0.09 (0.084), Comparative Fit Index and Tucker–Lewis Index > 0.9 (0.925 and 0.917, respectively). LSCAPE showed also good reliability (CR indices > 0.7) and validity (AVE > 0.5) measures. Finally, LSCAPE had moderate to strong associations with SF-12 sub-scales (>0.6) and a moderate relationship with income (>0.3). Thus, LSCAPE has been demonstrated to be a reliable and valid instrument in measuring living standards capabilities among the Spanish older population.
Chinese IR Scholarship as a Relational Epistemology in the Study of China's Rise
Authors: Wang Hung-jen
Published: April 2020

Current anti-Chinese sentiment in the international community has emerged from a knowledge-production background that entails the material fact of China's rising power and ideational factors tied to how the rising China phenomenon is interpreted. The ideational factors can be divided into two groups. One analyses China according to established Western IR theories that describe the country in terms of either threat or opportunity, thereby rendering China as part of an established universal ontology. A second group approaches China's experiences in a more sympathetic light, but still conceptualizes China's rise according to fixed categories such as “nation-state.” This paper argues that both of these groups are guilty of creating self-fulfilling prophecies – that is, they consistently theorize China in opposition to the West owing to the rational epistemology upon which they built their knowledge or perceptions of China. This epistemology conflicts with the efforts of Chinese IR scholars to evaluate China's rise in a relational manner.
Enabling parametric design space exploration by non-designers
Authors: Castro e Costa Eduardo , Jorge Joaquim , Knochel Aaron D. , Duarte José Pinto
Published: April 2020

In mass customization, software configurators enable novice end-users to design customized products and services according to their needs and preferences. However, traditional configurators hardly provide an engaging experience while avoiding the burden of choice. We propose a Design Participation Model to facilitate navigating the design space, based on two modules. Modeler enables designers to create customizable designs as parametric models, and Navigator subsequently permits novice end-users to explore these designs. While most parametric designs support direct manipulation of low-level features, we propose interpolation features to give customers more flexibility. In this paper, we focus on the implementation of such interpolation features into Navigator and its user interface. To assess our approach, we designed and performed user experiments to test and compare Modeler and Navigator, thus providing insights for further developments of our approach. Our results suggest that barycentric interpolation between qualitative parameters provides a more easily understandable interface that empowers novice customers to explore the design space expeditiously.
Poaching and its representation in Edwardian England, c. 1901–14
Authors: Ridgwell Stephen
Published: April 2020

The poacher has been closely studied by historians of crime and protest in England. While much has been done to reveal the complex nature of poaching, this work has tended to concentrate on the nineteenth century and been largely concerned with practice. By shifting attention to the opening decades of the twentieth century, and by focusing instead on representation, this article explores the place of the Edwardian poacher in a rapidly expanding cultural landscape. Pointing to an inverse relationship between physical presence and representational weight and throw, the article shows how the idea of the poacher was not just a by-product of Edwardian ruralism, but was integral to a deeply felt ruralist sensibility that strongly informed contemporary debates on the control and use of land and related matters of national identity and wellbeing. In considering how this ostensibly marginal figure became so embedded in the popular imagination, the full extent of the poacher’s cultural usability is revealed. Like ruralism itself, the representational poacher had many facets and served many needs.
The water path in plasma-treatedLeucaenaseeds
Authors: Alves-Junior Clodomiro , da Silva Dinnara L. S. , Vitoriano Jussier O. , Barbalho Anne P. C. B. , de Sousa Regina C.
Published: April 2020

The effects of cold atmospheric plasma (CAP) of dielectric barrier discharges on the wettability, imbibition and germination ofLeucaena leucocephalawere investigated. It was established that CAP treatment markedly hydrophilized the seed coat, especially at longer treatment times. From the profile of the imbibition curve and visual observation, it was possible to verify that there are two resistance barriers to water penetration: integument surface and region of the macrosclereid cell wall (light line). Although the plasma interacts only in the integument, increasing the density of hydrophilic sites increases the capacity of water absorption, producing enough driving force to overcome the second resistance barrier. The existence of these two barriers changes the three-phase pattern generally observed during seed germination. Despite an increase in imbibition, the plasma treatment conditions used in this work, were not enough to overcome completely the dormancy barrier.
Addressing the quality of communication with older cancer patients with cognitive deficits: Development of a communication skills training module
Authors: Korc-Grodzicki Beatriz , Alici Yesne , Nelson Christian , Alexander Koshy , Manna Ruth , Gangai Natalie , Shen Megan J. , Parker Patricia A. , Banerjee Smita C.
Published: April 2020

Objective

Effective communication is an essential part of patient-centered care. The complexity of cancer care in older adults makes communication challenging, particularly when older patients have cognitive deficits and lose their autonomy. This paper describes the development, implementation, and evaluation of a communication skills training module for health care providers (HCPs) who work with older adults with cancer, with or at risk of developing cognitive deficits.

Method

Using a pre-post single arm study design, 99 HCPs from a comprehensive cancer center in North-East USA, who worked primarily with geriatric patients, participated in the study. Participants included Advance Practice Providers (including Nurse Practitioners and Physician Assistants; n = 24, 24.2%); nurses (n = 23, 23.2%), social workers (n = 14, 14.1%), physicians (n = 13, 13.1%), and “other” HCPs (including occupational therapists, physical therapists, and psychologists; n = 20, 20.2%). The HCPs participated in a one-day geriatric communication skills training program in groups of 12–15 over a 2-year period. Participants complete pre-post surveys on module evaluation and perception of self-efficacy as well as pre-post video-recorded Standardized Patient Assessment (SPA) to evaluate communication skill uptake.

Results

Most participants evaluated the module positively; over 90% indicated that they agreed or strongly agreed with five of the six module evaluation items. HCPs’ self-efficacy in communicating with cancer patients with cognitive deficits significantly increased from pre- to post-module training. There was a significant increase in the following communication skill use from pre- to post-training: checking patient preferences, declaring agenda, and inviting agenda.

Significance of results

Results demonstrated a successful implementation of the program as evidenced through favorable program evaluation, significant gains in self-efficacy, as well as significant improvement in several communication skills.
Initial Land Use/Cover Distribution Substantially Affects Global Carbon and Local Temperature Projections in the Integrated Earth System Model
Authors: Di Vittorio A.V. , Shi X. , Bond‐Lamberty B. , Calvin K. , Jones A.
Published: April 2020

Initial land cover distribution varies among Earth system models, an uncertainty in initial conditions that can substantially affect carbon and climate projections. We use the integrated Earth System Model to show that a 3.9 M km2 difference in 2005 global forest area (9–14% of total forest area) generates uncertainties in initial atmospheric CO2 concentration, terrestrial carbon, and local temperature that propagate through a future simulation following the Representative Concentration Pathway 4.5. By 2095, the initial 6 ppmv uncertainty range increases to 9 ppmv and the initial 26 PgC uncertainty range in terrestrial carbon increases to 33 PgC. The initial uncertainty range in annual average local temperature of −0.74 to 0.96 °C persists throughout the future simulation, with a seasonal maximum in Dec‐Jan‐Feb. These results highlight the importance of accurately characterizing historical land use and land cover to reduce overall initial condition uncertainty.
On the Multifractal Features of Low‐Frequency Magnetic Field Fluctuations in the Field‐Aligned Current Ionospheric Polar Regions: Swarm Observations
Authors: Consolini G. , De Michelis P. , Alberti T. , Giannattasio F. , Coco I. , Tozzi R. , Chang T. T. S.
Published: April 2020

Recent findings on the nature of magnetic field fluctuations in the high‐latitude ionospheric regions have suggested the existence of scaling features, which are the signature of the occurrence of turbulence. These features mainly characterize the magnetic field fluctuations in those regions where the field‐aligned currents flow. Here, we investigate the nature of the Earth's magnetic field fluctuations using the high‐resolution (50 Hz) magnetic measurements from the European Space Agency Earth's observation mission Swarm. Our study indicates that spatiotemporal anomalous scaling features characterize low‐frequency magnetic field fluctuations in the high‐latitude ionospheric regions of field‐aligned currents at spatial scales in the range 0.8–80 km (timescales in the range 0.1–10 s). The signature of a multifractal nature of these fluctuations suggests a highly complex structure of the field‐aligned currents. Our results support the view of inhomogeneous (filamentary) field‐aligned currents, which can have relevant implications in the comprehension of the physical processes responsible for the magnetospheric‐ionospheric coupling and ionospheric heating.
The Shape of Mercury's Magnetopause: The Picture From MESSENGER Magnetometer Observations and Future Prospects for BepiColombo
Authors: Philpott L. C. , Johnson C. L. , Anderson B. J. , Winslow R. M.
Published: April 2020

The MErcury Surface, Space Environment, GEochemistry, and Ranging (MESSENGER) spacecraft orbited Mercury between March 2011 and April 2015, typically passing through the magnetosphere, magnetosheath, and interplanetary magnetic field, on each orbit. Using data from the Magnetometer, we identify magnetopause crossings for the complete orbital mission and model the average boundary shape. We find that Mercury's average magnetopause is well modeled by both an axisymmetric shape and a three‐dimensional shape containing indentations in the cusp regions and a magnetotail that is wider in the north‐south versus east‐west direction. Examination of MESSENGER data and the use of simulated crossings show that coverage is very limited in the cusp region. Parameters describing the indentation are poorly constrained, and model fits may be biased due to the combination of orbital geometry and magnetospheric dynamics. The distribution of MESSENGER data inside the magnetopause, together with minimum variance analysis of a representative subset of magnetopause crossings, hints at the presence of a cusp indentation, though likely shallower than that estimated from the observed crossing positions. The BepiColombo spacecraft will arrive at Mercury in 2025. We simulate expected data coverage and magnetopause crossings using both axisymmetric and three‐dimensional magnetopause models. BepiColombo will improve our understanding of the magnetopause shape by providing data over the southern hemisphere and regions of the northern cusp indentation not covered by MESSENGER. There is also the potential for simultaneous measurements of the interplanetary magnetic field and magnetopause position.
Neotethyan Subduction Ignited the Iran Arc and Backarc Differently
Authors: Shafaii Moghadam H. , Li Q. L. , Li X. H. , Stern R. J. , Levresse G. , Santos J. F. , Lopez Martinez M. , Ducea M. N. , Ghorbani G. , Hassannezhad A.
Published: April 2020

Most arcs show systematic temporal and spatial variations in magmatism with clear shifts in igneous rock compositions between those of the magmatic front (MF) and those in the backarc (BA). It is unclear if similar magmatic polarity is seen for extensional continental arcs. Herein, we use geochemical and isotopic characteristics coupled with zircon U‐Pb geochronology to identify the different magmatic style of the Iran convergent margin, an extensional system that evolved over 100 Myr. Our new and compiled U‐Pb ages indicate that major magmatic episodes for the NE Iran BA occurred at 110–80, 75–50, 50–35, 35–20, and 15–10 Ma. In contrast to NE Iran BA magmatic episodes, compiled data from MF display two main magmatic episodes at 95–75 and 55–5 Ma, indicating more continuous magmatism for the MF than for the BA. We show that Paleogene Iran serves as a useful example of a continental arc under extension. Our data also suggest that there is not a clear relationship between the subduction velocity of Neotethyan Ocean beneath Iran and magmatic activity in Iran. Our results imply that the isotopic compositions of Iran BA igneous rocks do not directly correspond to the changes in tectonic processes or geodynamics, but other parameters such as the composition of lithosphere and melt source(s) should be considered. In addition, changes in subduction zone dynamics and contractional versus extensional tectonic regimes influenced the composition of MF and BA magmatic rocks. These controls diminished the geochemical and isotopic variations between the magmatic front and backarc.
An Absolute Paleogeographic Positioning of the Early Permian Tarim Large Igneous Province
Authors: Wei Bitian , Yang Xingfeng , Cheng Xin , Domeier Mathew , Wu Hanning , Kravchinsky Vadim A. , Zhou Yanan , Jiang Nan , Wu Yiying , Huo Feifei , Zhang Weijie , Zhang Yichen , Shao Ruiqi
Published: April 2020

This paper presents a quantitative characterization of the early Permian latitude and longitude of the Tarim block and its relationship to the supercontinent Pangea using a combination of newly acquired paleomagnetic data and inferences drawn from the plume generation zone reconstruction method. Early Permian magmatic rocks from Tarim have previously been interpreted as constituents of a large igneous province (LIP) and were therefore possibly derived from a mantle plume originating at the core‐mantle boundary. Here, we present the results of a paleomagnetic investigation of early Permian rocks (~288 Ma) in the Keping area of northwestern Tarim. A stable high‐temperature component (HTC) was isolated from 413 samples from 51 sites. The directions of this HTC pass the fold test and are of exclusively reversed polarity, which is consistent with their acquisition during the late Carboniferous to mid‐Permian Kiaman Reverse Polarity Superchron, suggesting that the HTC is likely primary. From these results, we compute a new early Permian pole for Tarim: 50.1°N, 170.5°E, A95 = 3.6°. Taking the estimated eruption center of the Tarim LIP (41°N, 80°E) as a reference point, this pole restores the LIP to a paleolatitude of ~30° at 288 Ma. Given this paleolatitude estimate, we attempt to fit the LIP to the edge of one of the large low shear velocity provinces in the lowermost mantle. It is not feasible to reconstruct the Tarim LIP directly above the margins of either the African or Pacific large low shear velocity provinces, but its reconstructed position could potentially be associated with the “Perm” anomaly.
The 2017 Mw 5.5 Pohang Earthquake, South Korea, and Poroelastic Stress Changes Associated With Fluid Injection
Authors: Lim H. , Deng K. , Kim Y.H. , Ree J.‐H. , Song T.‐R. A. , Kim K.‐H.
Published: April 2020

The 2017 Mw 5.5 Pohang earthquake in South Korea, the first reported and largest magnitude‐induced earthquake, occurred near the enhanced geothermal power plant in Pohang on 15 November 2017. We compute the spatiotemporal changes in poroelastic stresses perturbed by injected fluid under various conditions to better understand the occurrences of the Pohang earthquake and the small‐magnitude earthquakes preceding it. Space‐time variation of the earthquakes that occurred before the Pohang earthquake correlates significantly with fluid injection history between January 2016 and September 2017. We attribute the timing in earthquake occurrence to slow fluid diffusion, making hydraulic diffusivity of bedrock the critical model parameter for representing this slow process. In this context, the delay between the injection and the Pohang earthquake requires diffusivity estimates within a range of 1 × 10−4–5 × 10−4 m2/s for damaged granodiorite at 4–5 km, corresponding to the depth range between the well and the focal depth. According to these estimates, the pore pressure and thus the Coulomb failure stress changes are further enhanced by each injection with minimum stress dissipation. We find fluid injection can result in a change of the Coulomb stress of up to 0.4–1.1 bar, exceeding those associated with the 2016 Mw 5.5 Gyeongju earthquake by 2 orders of magnitude.
Lagrangian Studies of Marine Production: A Multimethod Assessment of Productivity Relationships in the California Current Ecosystem Upwelling Region
Authors: Kranz Sven A. , Wang Seaver , Kelly Thomas B. , Stukel Michael R. , Goericke Ralf , Landry Michael R. , Cassar Nicolas
Published: April 2020

A multimethod process‐oriented investigation of diverse productivity measures in the California Current Ecosystem (CCE) Long‐Term Ecological Research study region, a complex physical environment, is presented. Seven multiday deployments covering a transition region from high to low productivity were conducted over two field expeditions (spring 2016 and summer 2017). Employing a Lagrangian study design, water parcels were followed over several days, comparing 24‐h in situ measurements (14C and 15NO3 ‐uptake, dilution estimates of phytoplankton growth, and microzooplankton grazing) with high‐resolution productivity measurements by fast repetition rate fluorometry (FRRF) and equilibrium inlet mass spectrometry (EIMS), and integrated carbon export measuremnts using sediment traps. Results show the importance of accounting for temporal and fine spatial scale variability when estimating ecosystem production. FRRF and EIMS measurements resolved diel patterns in gross primary and net community production. Diel productivity changes agreed well with comparably more traditional measurements. While differences in productivity metrics calculated over different time intervals were considerable, as those methods rely on different base assumptions, the data can be used to explain ecosystem processes which would otherwise have gone unnoticed. The processes resolved from this method comparison further understanding of temporal and spatial coupling and decoupling of surface productivity and potential carbon burial in a gradient from coastal to offshore ecosystems.
Fluxes of Atmospheric Greenhouse‐Gases in Maryland (FLAGG‐MD): Emissions of Carbon Dioxide in the Baltimore, MD‐Washington, D.C. Area
Authors: Ahn D. Y. , Hansford J. R. , Howe S. T. , Ren X. R. , Salawitch R. J. , Zeng N. , Cohen M. D. , Stunder B. , Salmon O. E. , Shepson P. B. , Gurney K. R. , Oda T. , Lopez‐Coto I. , Whetstone J. , Dickerson R. R.
Published: April 2020

To study emissions of CO2 in the Baltimore, MD‐Washington, D.C. (Balt‐Wash) area, an aircraft campaign was conducted in February 2015, as part of the Fluxes of Atmospheric Greenhouse‐Gases in Maryland (FLAGG‐MD) project. During the campaign, elevated mole fractions of CO2 were observed downwind of the urban center and local power plants. Upwind flight data and Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model analyses help account for the impact of emissions outside the Balt‐Wash area. The accuracy, precision, and sensitivity of CO2 emissions estimates based on the mass balance approach were assessed for both power plants and cities. Our estimates of CO2 emissions from two local power plants agree well with their Continuous Emissions Monitoring Systems (CEMS) records. For the 16 power plant plumes captured by the aircraft, the mean percentage difference of CO2 emissions was −0.3%. For the Balt‐Wash area as a whole, the 1𝜎 CO2 emission rate uncertainty for any individual aircraft‐based mass balance approach experiment was ±38%. Treating the mass balance experiments, which were repeated seven times within 9 days, as individual quantifications of the Balt‐Wash CO2 emissions, the estimation uncertainty was ±16% (standard error of the mean at 95% CL). Our aircraft‐based estimate was compared to various bottom‐up fossil fuel CO2 (FFCO2) emission inventories. Based on the FLAGG‐MD aircraft observations, we estimate 1.9 ± 0.3 MtC of FFCO2 from the Balt‐Wash area during the month of February 2015. The mean estimate of FFCO2 from the four bottom‐up models was 2.2 ± 0.3 MtC.
A Comprehensive Estuarine Dissolved Organic Carbon Budget Using an Enhanced Biogeochemical Model
Authors: Clark J. B. , Long W. , Hood R. R.
Published: April 2020

Complicated biogeochemical cycling and differential organic matter reactivity make quantifying the relative contribution of a given source of organic carbon to the standing stock within an estuary difficult. Here, a new model of tidal marsh‐estuary organic carbon cycling is presented for the Rhode River, MD, a well‐studied tributary of the Chesapeake Bay, USA. A dissolved organic carbon (DOC) budget was estimated by summing the source and sink terms and the advection of water within the tributary. 13.1% and 15.3% of the total DOC input to the Rhode River entered from the marsh and the watershed, respectively, and 52.6% was derived from phytoplankton production. Extrapolating to the entire year, 35.5 Mg of DOC is exported to the main stem of Chesapeake Bay annually, which accounts for 12.3% of the total allochthonous and autochthonous inputs to the estuary. Removing the modeled marsh at the head of the Rhode River decreased export of DOC to the main stem by 39.2%, and up to 56% of the estuarine DOC standing stock can be attributed to the marsh. The model described here can be used across temperate estuarine systems and provides a new methodology for quantifying the amount of DOC that can be attributed to or lost by specific source and sink pathways.
Statistical Dependence of EMIC Wave Scattering on Wave and Plasma Parameters
Authors: Qin Murong , Hudson Mary , Millan Robyn , Woodger Leslie , Shen Xiaochen
Published: April 2020

A recent statistical study (Qin et al., 2018, https://doi.org/10.1029/2018JA025419) has suggested that not all electromagnetic ion cyclotron (EMIC) waves can scatter relativistic electrons. However, knowledge of the factors that influence the EMIC wave scattering efficiency is still limited in observations. In our study, we perform 6 years of analysis of data from 2013 to 2018, with relativistic electron precipitation (REP) observed by POES and EMIC wave observations from Van Allen Probes. The coincidence occurrence rate between EMIC waves and relativistic electron precipitation events is about 34%. Proportion of different bands of EMIC wave events that are associated with REP is as follows: H+ band and He+ band waves occurring simultaneously >H+ band >He+ band occurrence, same as in our previous study (Qin et al., 2018, https://doi.org/10.1029/2018JA025419). It is also found that the coincidence occurrence rate of EMIC wave events and REP events increases with respect to increased background plasma density, with increases in the ratio of plasma frequency to local gyrofrequency, increasing EMIC wave power and when the wave frequency approaches the gyrofrequency. The dependence on background electron density is stronger than the dependence on the ratio of plasma frequency to gyrofrequency. The coincidence occurrence rate decreases as the magnetic field increases between 120 and 270 nT, consistent with a previous study. These results are critical for better understanding and predicting the REP into the upper atmosphere due to EMIC waves.
Damage Evolution During Rock Pulverization Induced by Dynamic Compressive Loading
Authors: Yao W. , Xu Y. , Xia K.
Published: April 2020

Rock pulverization is a geological process in which fault zone rocks are shattered in situ, into fine grains much smaller than the original grain size, without significant shear strain. Investigations regarding the genesis of pulverized fault zone rock (PFZR) suggested that it is a coseismic phenomenon and may be closely associated with supershear earthquakes. The observation of dynamic damage evolution is thus significant for understanding the rock pulverization mechanism due to dynamic compressive load. In this study, the damage evolution of Laurentian granite under dynamic compression loading is studied by using the strain control technique in a split Hopkinson pressure bar system. Dynamic compression experiments are performed under different maximum strain levels and different loading rates. Tested specimens are recovered for postmortem examination with X‐ray micro‐computed tomography and microscopic observation. 3‐D microcrack networks due to different dynamic loading rates are examined, and the evolution of the crack volume and crack number at various loading rates are analyzed. The results reveal that the pulverization process during dynamic compression loading is categorized into three stages. Both a high loading rate and a sufficient strain are necessary for the rock pulverization to occur. The main features of fractures during rock pulverization are discussed, and the total dissipated energy for dynamic fracture and pulverization is quantified.
Ten Years After the Wenchuan Earthquake: New Insights Into the Geodynamics of the Eastern Tibet
Authors: Zhang Huiping , Kirby Eric , Li Haibing , Cook Kristen , Zhang Peizhen
Published: April 2020

In 2008, the Mw 7.9 Wenchuan earthquake killed >80,000 and injured more than 370,000 people in the province of Sichuan, China. About 5 years later, Mw 6.6 Lushan earthquake occurred on 20 April 2013, only ~90 km further south. More recently, in 2017, a third event, Mw 6.5 Jiuzhaigou earthquake, occurred ~250 km north of the Wenchuan earthquake epicenter. These events were all along the Longmen Shan thrust belt in eastern Tibet. The questions posed by these events still reverberate in the Chinese and international geoscience communities. In this special section, we summarize and report new data sets, observations, and modeling results of the eastern Tibet during the last decade. It covers the tectonics of eastern Tibet, the seismology, and the surface response of the earthquake. All these contributions will provide new insights into the geodynamics of the eastern Tibet. We further highlight a number of outstanding questions that remain to be addressed.
The force awakens: metastatic dormant cancer cells
Authors: Park So-Yeon , Nam Jeong-Seok
Published: April 2020

Recurrent cancer that spreads to distant sites is the leading cause of disease-related death among cancer patients. Cancer cells are likely to disseminate during cancer progression, and some may enter dormancy, remaining viable but not increasing. These dormant cancer cells (DCCs) are rarely detectable with current diagnostic systems. Moreover, they can interpret homoeostatic signals from the microenvironment, thereby evading immune surveillance and chemotherapy. Eventually, DCCs can reawaken in response to signals, which are not yet fully understood, resulting in recurrence and metastasis. Therefore, understanding the biology of DCC reawakening is key to preventing metastasis. Over the last decade, a growing body of literature has revealed the mechanisms involved in cancer dormancy and reawakening. The cytotoxic activity of immune cells can cause cancer cells to enter a dormant state, and chronic inflammation can reactivate cancer proliferation at distant sites. Upon the binding of circulating DCCs to extracellular molecules, various signaling cascades are activated and reinitiate cell proliferation. In the present review, we attempt to consolidate the existing literature to provide a framework for the understanding of this crucial step in cancer progression.
Somatic mutations in the DNA repairome in prostate cancers in African Americans and Caucasians
Authors: Yadav Santosh , Anbalagan Muralidharan , Baddoo Melody , Chellamuthu Vinodh K. , Mukhopadhyay Sudurika , Woods Carol , Jiang Wei , Moroz Krzysztof , Flemington Erik K , Makridakis Nick
Published: April 2020

Most hereditary tumors show aberrations in DNA repair genes or their regulators. In contrast, only a minority of sporadic tumors show alterations in these genes. As a result, genomic instability is currently considered an enhancer of tumorigenesis rather than an obligatory event in this process. However, tumor heterogeneity presents a significant technical challenge for most cancer genomics studies performed at less than 100× mean resolution depth. To address the importance of genomic instability in prostate carcinogenesis and tumor progression, we performed ultrahigh depth exome sequencing of 124 DNA damage repair/response (repairome) genes in 63 tumors and matched normal tissue samples in African Americans and Caucasians. The average sequence depth was 712-fold for DNA isolated from normal tissue and 368-fold for FFPE tumors. We identified 671 somatic mutations in tumors from African Americans and 762 somatic mutations in tumors in Caucasians. The most frequently mutated DNA repairome genes were EXO1, ATR, POLQ, NEIL3, ERCC6, BRCA2, BRCA1, XPC, JAG1, RPA1, POLE, ATM, and LIG1 in African American men, and POLQ, NEIL3, POLB, BRCA2, EXO1, ERCC6, ATR, RBBP8, BRCA1, ATM, JAG1, XPC, and POLE in Caucasians. We found that 89% of tumors had at least one mutation in nucleotide excision repair pathway genes in African Americans, whereas >40% of tumors had mutations in base excision repair pathway genes in Caucasians. We further identified a marginal increase in mutation rate in tumors in African Americans with increasing age. Tumors in Caucasians did not show a correlation with age, but a progressive increase in the mutation rate was observed at higher Gleason scores. Our data reveal significant differences in the molecular signatures in the DNA repairome in prostate cancer between African Americans and Caucasians. These data also have substantial implications regarding the well-known health disparities in prostate cancer, such as the higher mortality in African Americans than Caucasians.