bluuebunny/crossref_metadata_2025 huggingface dataset:
Meta-User2Vec model for addressing the user and item cold-start problem in recommender systems
Authors: Misztal-Radecka Joanna , Indurkhya Bipin , Smywiński-Pohl Aleksander
Published: October 2020

The cold-start scenario is a critical problem for recommendation systems, especially in dynamically changing domains such as online news services. In this research, we aim at addressing the cold-start situation by adapting an unsupervised neural User2Vec method to represent new users and articles in a multidimensional space. Toward this goal, we propose an extension of the Doc2Vec model that is capable of representing users with unknown history by building embeddings of their metadata labels along with item representations. We evaluate our proposed approach with respect to different parameter configurations on three real-world recommendation datasets with different characteristics. Our results show that this approach may be applied as an efficient alternative to the factorization machine-based method when the user and item metadata are used and hence can be applied in the cold-start scenario for both new users and new items. Additionally, as our solution represents the user and item labels in the same vector space, we can analyze the spatial relations among these labels to reveal latent interest features of the audience groups as well as possible data biases and disparities.
Toward interprofessional team training for surgeons and anesthesiologists using virtual reality
Authors: Chheang Vuthea , Fischer Virve , Buggenhagen Holger , Huber Tobias , Huettl Florentine , Kneist Werner , Preim Bernhard , Saalfeld Patrick , Hansen Christian
Published: October 2020

Purpose

In this work, a virtual environment for interprofessional team training in laparoscopic surgery is proposed. Our objective is to provide a tool to train and improve intraoperative communication between anesthesiologists and surgeons during laparoscopic procedures.

Methods

An anesthesia simulation software and laparoscopic simulation software are combined within a multi-user virtual reality (VR) environment. Furthermore, two medical training scenarios for communication training between anesthesiologists and surgeons are proposed and evaluated. Testing was conducted and social presence was measured. In addition, clinical feedback from experts was collected by following a think-aloud protocol and through structured interviews.

Results

Our prototype is assessed as a reasonable basis for training and extensive clinical evaluation. Furthermore, the results of testing revealed a high degree of exhilaration and social presence of the involved physicians. Valuable insights were gained from the interviews and the think-aloud protocol with the experts of anesthesia and surgery that showed the feasibility of team training in VR, the usefulness of the system for medical training, and current limitations.

Conclusion

The proposed VR prototype provides a new basis for interprofessional team training in surgery. It engages the training of problem-based communication during surgery and might open new directions for operating room training.
Transversus Abdominis Plane Block Appears to Be Effective and Safe as a Part of Multimodal Analgesia in Bariatric Surgery: a Meta-analysis and Systematic Review of Randomized Controlled Trials
Authors: Földi Mária , Soós Alexandra , Hegyi Péter , Kiss Szabolcs , Szakács Zsolt , Solymár Margit , Pétervári Erika , Balaskó Márta , Kusza Krzysztof , Molnár Zsolt
Published: October 2020

Purpose

Pain after bariatric surgery can prolong recovery. This patient group is highly susceptible to opioid-related side effects. Enhanced Recovery After Surgery guidelines strongly recommend the administration of multimodal medications to reduce narcotic consumption. However, the role of ultrasound-guided transversus abdominis plane (USG-TAP) block in multimodal analgesia of weight loss surgeries remains controversial.

Materials and Methods

A systematic search was performed in four databases for studies published up to September 2019. We considered randomized controlled trials that assessed the efficacy of perioperative USG-TAP block as a part of multimodal analgesia in patients with laparoscopic bariatric surgery.

Results

Eight studies (525 patients) were included in the meta-analysis. Pooled analysis showed lower pain scores with USG-TAP block at every evaluated time point and lower opioid requirement in the USG-TAP block group (weighted mean difference (WMD) = − 7.59 mg; 95% CI − 9.86, − 5.39; p < 0.001). Time to ambulate was shorter with USG-TAP block (WMD = − 2.22 h; 95% CI − 3.89, − 0.56; p = 0.009). This intervention also seemed to be safe: only three non-severe complications with USG-TAP block were reported in the included studies.

Conclusion

Our results may support the incorporation of USG-TAP block into multimodal analgesia regimens of ERAS protocols for bariatric surgery.
Ostdeutsche Identität(en) im Wandel? Perspektiven für Intra- und Interkohortenvergleiche
Authors: Vogel Lars , Leser Julia
Published: October 2020

Der Beitrag analysiert ostdeutsche Identitätsbildungsprozesse bei jungen Erwachsenen im Jahr 2004 und rund zehn Jahre später. Empirische Basis ist ein Intra- und Interkohortenvergleich der Befunde von drei qualitativen Studien basierend auf Leitfadeninterviews und Gruppendiskussionen. Dieser diachrone Vergleich zeigt partielle Kontinuitäten in den Identitätskonstruktionen der ostdeutschen Befragten: Die wahrgenommene Abwertung Ostdeutschlands bildet weiterhin den zentralen Ausgangspunkt der Identifizierung als ostdeutsch und die Reaktionen darauf sind ebenso weiterhin heterogen. Diese Heterogenität wird zu einer Typologie verdichtet: Manche Ostdeutsche zielen auf eine Aufwertung ihrer kollektiven Identität durch Umdeutung und beziehen sich dabei auf kollektivistische Werte oder die gelungene Bewältigung der Systemtransformation. Andere lehnen die Identifikation als ostdeutsch und die Klassifizierung in Ost und West als überholt und illegitim ab. Allerdings lässt der nach 1990 geborene Teil dieser Gruppe zusätzlich individuelle Strategien instrumenteller Identitätsbildung erkennen. Diese Heterogenität ostdeutscher Identität(en) kann auf Kohortenunterschiede und soziale Merkmale der Probanden zurückgeführt werden. Zugleich wird der Einfluss des Forschungsdesigns und insbesondere der Fallauswahl der einbezogenen Studien auf die Ergebnisse methodologisch diskutiert. Die Befunde dienen damit als Ausgangspunkte für zukünftige Intra- und Interkohortenvergleiche, in denen die individuellen und methodischen Einflussfaktoren für Identitätsbildungsprozesse stärker berücksichtigt werden sollten.
Field methods of a near-bed suspended sediment experiment in the Yangtze River, China
Authors: Shu Caiwen , Tan Guangming , Lv Yiwei , Xu Quanxi
Published: October 2020

Using experimental data of near-bed suspended sediment concentrations at five typical hydrometric stations of the Three Gorges Reservoir at the early reserving stage, the differences were investigated between the common method and improved method during flood seasons and non-flood seasons. The impact of taking measurements below 0.2 times the water depth on the results was discussed. The results show that the average discharges and velocities at each station calculated by the common method were slightly larger than those calculated by the improved method. Regarding the suspended sediment concentration at each station, the errors in the reservoir and downstream channels in dynamic equilibrium state were small, and the largest errors occurred where the river bed was strongly scoured in the downstream reach below the large dam. There was no significant relationship between water discharge and flow velocity, and the missed measurement phenomenon also occurred. The sediment discharge error was affected by the suspended sediment concentration, implying that errors usually occurred in channels with serious erosion during flood seasons. The correction coefficients (R2) of sediment discharge at each station were given during the experiment, which showed that the sediment discharges at the hydrometric stations where a large amount of sediment transport occurred near the river bottom, needed to be modified. Furthermore, the test methods proposed in this study were applied to calculate the sediment discharges of three rivers, and the results indicate that this method can narrow the gap between bathymetric comparisons and sediment load measurements.
Classes of meromorphic harmonic functions and duality principle
Authors: Dziok Jacek
Published: October 2020

We introduce new classes of meromorphic harmonic univalent functions. Using the duality principle, we obtain the duals of such classes of functions leading to coefficient bounds, extreme points and some applications for these functions.
Better, Virtually: the Past, Present, and Future of Virtual Reality Cognitive Behavior Therapy
Authors: Lindner Philip
Published: October 2020

Virtual reality (VR) is an immersive technology capable of creating a powerful, perceptual illusion of being present in a virtual environment. VR technology has been used in cognitive behavior therapy since the 1990s and accumulated an impressive evidence base, yet with the recent release of consumer VR platforms came a true paradigm shift in the capabilities and scalability of VR for mental health. This narrative review summarizes the past, present, and future of the field, including milestone studies and discussions on the clinical potential of alternative embodiment, gamification, avatar therapists, virtual gatherings, immersive storytelling, and more. Although the future is hard to predict, clinical VR has and will continue to be inherently intertwined with what are now rapid developments in technology, presenting both challenges and exciting opportunities to do what is not possible in the real world.
Leveraging Digital Intelligence for Community Well-Being
Authors: Narayan Rumy
Published: October 2020

The world of information is mediated by digital technologies, and the growing influence of Artificial Intelligence (AI) on society, through its involvement in everyday life, is likely to present issues with lasting consequences. In the context of improving community well-being using AI, the knowledge, insights, and impressions or analysis required for activating such improvement necessitate a frame of reference. This frame needs to take into account how well-being is understood within the current paradigm of technological innovation as a driver of economic growth. The evaluation of well-being, often defined as an individual’s cognitive and affective assessment of life, takes into account emotional reaction to events based on how satisfaction and fulfillment are discerned. It is a dynamic concept that involves subjective, social, and psychological dimensions, along with a state of being where human needs are met and one can act meaningfully, thus highlighting a relational element underlying social and community well-being. Transitions from a predominantly industrial society towards one that is information-led demand a strategic social design for AI. This article evaluates how well-being is understood within the current paradigm to offer a framework for leveraging AI for community well-being.
Performing Early Modern Drama Beyond Shakespeare
Authors: McCarthy Harry R.
Published: October 2020

This Element provides the first in-depth study of the present-day all-boy company, Edward's Boys, who are based at King Edward VI School ('Shakespeare's School') in Stratford-upon-Avon. Since 2005, the company has produced a wide array of early modern plays, providing the most substantial repertory of early modern drama available for examination by scholars. The Element provides a comprehensive account of the company's practices, drawing on extensive rehearsal and performance observation, evidence from the company's archive, and interviews with actors and key company personnel. The Element takes account of the company's particular educational and strongly interpersonal environment, suggesting that these factors have a distinctive shaping force on their performance practice. In the hands of Edward's Boys, the Element argues, early modern drama becomes the source of company creation, ensemble practice, and virtuosic physical play, inviting us to reimagine what it means – and takes – to perform these plays today.
State of the Netherlands v. Urgenda Foundation
Authors: Meguro Maiko
Published: October 2020

The judgment in State of the Netherlands v. Urgenda Foundation marks one of the first successful challenges to climate change policy based on a human rights treaty. In this case, the Dutch Supreme Court upheld the lower court's opinion that the Netherlands has a positive obligation under the European Convention on Human Rights (ECHR) to take reasonable and suitable measures for the prevention of climate change. Although the Supreme Court recognized that climate change is a consequence of collective human activities that cannot be solved by one state on its own, it held that the Netherlands is individually responsible for failing to do its part to counter the danger of climate change, which, as the Court affirmed, inhibits enjoyment of ECHR rights. In reaching that conclusion, the Supreme Court determined the exact level of greenhouse gas (GHG) emissions reduction that the Netherlands is required to meet to comply with its ECHR obligation, specifically, a 25 percent reduction compared to its 1990 level by the end of 2020.
Modest International Law: COVID-19, International Legal Responses, and Depoliticization
Authors: Quintana Francisco-José , Uriburu Justina
Published: October 2020

In this Essay, we analyze two sets of international legal responses to the COVID-19 pandemic: the academic discussion on state responsibility; and the deployment of international law as a tool for resistance. We argue that both approaches made significant contributions but concealed the role of the discipline in the production of the conditions that led to the pandemic and its unequal impact. These interventions reflect a “modest international law”; an understanding of the discipline that hinders change and is ethically weak. We contend that repoliticization can help reclaim international law's ambition and responsibility.
“Lest We Should Sleep”: COVID-19 and Human Rights
Authors: Bennoune Karima
Published: October 2020

Any meaningful human rights law approach to COVID-19 must be holistic and recognize the breadth of the challenges to both economic, social, and cultural rights, and civil and political rights. It must be grounded in the threat posed by the disease but also address responses to it, and implicate a wide range of state and nonstate actors. Such an analysis should offer a positive vision of effective global reaction, and counter attempts to hijack rights to oppose legitimate pandemic measures.
The Pandemic Paradox in International Law
Authors: Danchin Peter G. , Farrall Jeremy , Rana Shruti , Saunders Imogen
Published: October 2020

This Essay examines a series of paradoxes that have rendered the international legal order's mechanisms for collective action powerless precisely when they are needed most to fight COVID-19. The “patriotism paradox” is that disengagement from the international legal order weakens rather than strengthens state sovereignty. The “border paradox” is that securing domestic populations by excluding noncitizens, in the absence of accompanying regulatory mechanisms to secure adherence to internal health measures, accelerates viral spread among citizens. The “equality paradox” is that while pandemics pose an equal threat to all people, their impacts compound existing inequalities.
United States—Anti-dumping Measures Applying Differential Pricing Methodology to Softwood Lumber from Canada
Authors: Ridi Niccolò
Published: October 2020

This dispute, brought by Canada against the United States, constitutes another chapter in three separate sagas: the enduring softwood lumber dispute between the two North American nations; the debate over the acceptability of the practice of “zeroing”; and the fight over the value and role of World Trade Organization (WTO) Appellate Body precedent. Notably, the panel departed from established Appellate Body decisions finding, inter alia, that zeroing was permissible under a weighted average-to-transaction (W-T) methodology. This departure is remarkable, not just because it runs counter to prior jurisprudence, but also for the reasoning supporting it and the circumstances in which it occurred. Indeed, the Panel Report was issued in the midst of a crisis of the WTO dispute settlement system arising from the United States’ decision to block the reappointment of Appellate Body members. The United States justified this action, which eventually resulted in the Appellate Body losing its quorum to hear new appeals on December 10, 2019, on the basis of complaints, among others, that the Appellate Body had championed an approach to precedent that the United States found incompatible with the intended role of dispute settlement within the WTO. While members worked feverishly to formulate a compromise that might respond to the United States’ criticisms and soften the effect of the Appellate Body's approach, the Panel suggested its own. Thus, it found room to depart from prior precedent (which the United States argued had been wrongly decided) while paying lip service to the Appellate Body.
Understanding viral shedding of severe acute respiratory coronavirus virus 2 (SARS-CoV-2): Review of current literature
Authors: Fontana Lauren M. , Villamagna Angela Holly , Sikka Monica K. , McGregor Jessina C.
Published: October 2020

Objective:

Transmission of SARS-CoV-2 has significant implications for hospital infection prevention and control, discharge management, and public health. We reviewed available literature to reach an evidenced-based consensus on the expected duration of viral shedding.

Design:

We queried 4 scholarly repositories and search engines for studies reporting SARS-CoV-2 viral shedding dynamics by PCR and/or culture available through September 8, 2020. We calculated the pooled median duration of viral RNA shedding from respiratory and fecal sources.

Results:

The review included 77 studies on SARS-CoV-2. All studies reported PCR-based testing and 12 also included viral culture data. Among 28 studies, the overall pooled median duration of RNA shedding from respiratory sources was 18.4 days (95% CI, 15.5–21.3; I2 = 98.87%; P < .01). When stratified by disease severity, the pooled median duration of viral RNA shedding from respiratory sources was 19.8 days (95% CI, 16.2–23.5; I2 = 96.42%; P < .01) among severely ill patients and 17.2 days (95% CI, 14.0–20.5; I2 = 95.64%; P < .01) in mild-to-moderate illness. Viral RNA was detected up to 92 days after symptom onset. Viable virus was isolated by culture from −6 to 20 days relative to symptom onset.

Conclusions:

SARS-COV-2 RNA shedding can be prolonged, yet high heterogeneity exists. Detection of viral RNA may not correlate with infectivity since available viral culture data suggests shorter durations of shedding of viable virus. Additional data are needed to determine the duration of shedding of viable virus and the implications for risk of transmission.
“All Parties Treat Silesians Instrumentally”: On Political Representation at the Regional Level
Authors: Turska-Kawa Agnieszka , Glajcar Rafał
Published: October 2020

The turn of the 20th century experienced an intensification of processes that strengthened Silesian identity, which became an important element of political debate in the region. This was reflected in the emergence of a growing number of entities that placed Silesian issues among their priority objectives and defined themselves as representatives of the interests of Silesia and Silesians. The aim of the study was to verify the political representative potential of groups in Upper Silesia. We accepted the hypothesis that the stronger the identity of a particular group (regional or national) the greater the probability that entities placing fundamental objectives strictly within the scope of regional issues should enjoy broad support in the region, and such entities consequently should be perceived as political representatives of the group. A study conducted using the categorized interview method (N=54) proves quite clearly that Silesians are unable to identify entities on the regional political scene that could represent them sufficiently. The determinants of this state of affairs are found not only in the negative actions of political entities but also in the absence of a clear vision of representation, which could constitute a basis for the formulated expectations of Silesians.
Non-resonant acceleration of charged particles driven by the associated effects of the radiation reaction
Authors: Russman F. , Almansa I. , Peter E. , Marini S. , Rizzato F. B.
Published: October 2020

In the present analysis, we study effects of the radiation reaction (RR) on the dynamics of charged particles submitted to the action of localized longitudinal high-frequency carriers travelling at the speed of light. As the wave's crests and troughs keep overtaking particles, dissipative RR forces tend to drag particles alongside the wave in an effort to reduce the relative wave–particle speed. Particles of course never reach the phase velocity of the wave, but are instead driven to an ever-growing velocity, towards the speed of light, while in the wave localization region. We developed a modified average Hamiltonian formalism capable of describing the intricacies of the corresponding dynamics. The modified formalism agrees with simulations and is of particular usefulness in the study of optimum values for the localization length and maximum wave amplitude.
Personnes âgées à domicile avec limitations fonctionnelles : étude préliminaire d’une intervention centrée sur le bien-être et l’autonomie
Authors: Meynet Stéphanie , Beaudoin Marine , Smeding Annique
Published: October 2020

In the context of demographic aging, preventing autonomy loss is a major issue. Adapting care systems to help keep seniors at home is a daily challenge. “La Mutualité Française”, a national mutual insurance company, has implemented in one of its healthcare services an innovative program to strengthen well-being: “The Well-Being Autonomy Pole.” This program comprises five Prevention and Support Care components and hypothesizes that strengthening the well-being of elderly people already suffering from physical limitations would prevent their autonomy decline. The originality of this program is its focus on elderly people who have rarely been studied in terms of preventing autonomy loss, given their existing functional limitations. A first evaluation was carried out over three months to verify the methodological feasibility of an impact assessment and to provide preliminary results on the effectiveness of the program. Key findings suggest improved levels of self-esteem, physical well-being, psychological autonomy and decreased anxiety. Methodological limitations of this first feasibility assessment and perspectives for future research are discussed.
Safety and effect of sildenafil on treating paediatric pulmonary arterial hypertension: a meta-analysis on the randomised controlled trials
Authors: Zhang Qingyou , Xu Bowen , Lv Jichen , Wang Zhijian , Du Junbao
Published: October 2020

Background:

Efficacy of sildenafil in treating paediatric pulmonary arterial hypertension is controversial. This systematic review aimed to explore the safety and effect of sildenafil on treating paediatric pulmonary arterial hypertension (PAH) through meta-analysis.

Methods and results:

In this study, the electronic databases, including the Cochran Library database, EMBASE, and MEDLINE were systemically retrieved to identify the related randomised controlled trials (RCTs). Two reviewers had independently completed study selection, data collection, and assessment of the bias risk. Amongst 938 articles researched according to our retrieval strategy, 15 papers that involved 673 cases had been screened. Relative to control group, the sildenafil group had markedly reduced mortality (RR = 0.25, 95% CI: 0.12–0.51; p < 0.0001), but difference within the mortality was not statistically significant between high- and low-dose sildenafil groups (p = 0.152). Nonetheless, difference of the mean pulmonary arterial pressure between sildenafil as well as control group was of no statistical significance. Differences in the length of hospital stay and the incidences of pulmonary hypertensive crisis between children with PAH and controls were of no statistical significance. However, the summary estimate favoured that sildenafil reduced the duration of mechanical ventilation time, as well as the length of ICU stay and inotropic support.

Conclusions:

Sildenafil therapy reduces the mortality of PAH patients, but its effects on the haemodynamic outcomes and other clinical outcomes are still unclear.
Safety and effectiveness of lurasidone in adolescents with schizophrenia: results of a 2-year, open-label extension study
Authors: Correll Christoph U. , Findling Robert L. , Tocco Michael , Pikalov Andrei , Deng Ling , Goldman Robert
Published: October 2020

Background

Minimal long-term benefit: Risk data are available regarding antipsychotic treatments for schizophrenia in pediatric populations. This study evaluated the long-term safety, tolerability, and effectiveness of lurasidone in adolescents with schizophrenia.

Methods

Patients aged from 13 to 17 who completed 6 weeks of double-blind (DB), placebo-controlled treatment with lurasidone were enrolled in a 2-year, open-label (OL), flexible dose (20-80 mg/day) lurasidone treatment study. Safety was assessed via spontaneous reporting, rating scales, body weight measurement, metabolic, and prolactin testing. Effectiveness measures included the Positive and Negative Syndrome Scale (PANSS) total score.

Results

About 271 patients completed 6 weeks of DB treatment and entered the 2-year OL extension study. Altogether, 42.4% discontinued prematurely, 10.7% due to adverse events. During OL treatment, the most common adverse events were headache (24.0%); anxiety (12.9%), schizophrenia, and nausea (12.5%); sedation/somnolence (12.2%); and nasopharyngitis (8.9%). Minimal changes were observed on metabolic parameters and prolactin. Mean change from DB baseline in weight at week 52 and week 104 was +3.3 kg and + 4.9 kg, respectively, compared to an expected weight gain of +3.4 kg and + 5.7 kg, respectively, based on the sex- and age-matched US Center for Disease Control normative data. Continued improvement was observed in PANSS total score, with mean change from OL baseline of −15.6 at week 52 and −18.4 at week 104.

Conclusion

In adolescents with schizophrenia, long-term lurasidone treatment was associated with minimal effects on body weight, lipids, glycemic indices, and prolactin. Continued improvement in symptoms of schizophrenia was observed over 2 years of lurasidone treatment.
A compact band-notched antenna with high isolation for UWB MIMO applications
Authors: Masoodi Issmat Shah , Ishteyaq Insha , Muzaffar Khalid , Magray M. Idrees
Published: October 2020

A compact antenna module with a single band notch at wireless local area network (WLAN) (5.725–5.825 GHz) for ultra-wideband (UWB) multiple input multiple output (MIMO) applications is proposed. Proposed antenna which acquires size of 0.299 λ × 0.413 λ × 0.005 λ mm3 at 3.1 GHz consists of two symmetrical radiators placed side by side on global merchandise link (GML) 1000 substrate (εr = 3.2, tan δ = 0.004). Isolation between the antenna elements is >18 dB in the whole UWB band, which is achieved by introducing the vertical stub and H-slot between the monopole radiators in the ground plane. The simulated and measured results of the antenna system are in good agreement. The proposed antenna covers entire UWB with impedance bandwidth (|S11| < −15 dB) from 3.1 to 11 GHz except at WLAN notched band. The designed antenna module bears low envelope correlation coefficient and minimal multiplexing efficiency hence fulfilling criteria suitable for various wireless MIMO applications.
Raising Our Voices for Diversity in the Geosciences
Authors: Bloemendaal Lucila , Matos Katarena , Walters Kendra , Sengupta Aditi
Published: October 2020

To achieve the goals in their aspirational diversity statements, organizations must actively recruit, mentor, and support scientists from every sector of society.
Modeling the Cascading Infrastructure Impacts of Climate Change
Authors: Wheeling Kate
Published: October 2020

New research highlights how interdependences among infrastructure systems like roads can complicate climate adaptation.
Dune Universe Inspires Titan's Nomenclature
Authors: Wendel JoAnna
Published: October 2020

Across the solar system, science collides with science fiction in literary ways.
OMPS LP Observations of PSC Variability During the NH 2019–2020 Season
Authors: DeLand Matthew T. , Bhartia Pawan K. , Kramarova Natalya , Chen Zhong
Published: October 2020

Seasonal ozone depletion in the polar regions (during late winter and early spring) depends on the presence and distribution of polar stratospheric clouds (PSCs). In this paper, we present new satellite observations of PSCs by the Ozone Mapping and Profiler Suite (OMPS) Limb Profiler (LP) instrument. LP cloud detections are identified as PSCs based on location, altitude, and background atmosphere temperature. The hyperspectral capabilities of OMPS LP enable PSC detection to occur concurrent with stratospheric ozone measurements from the same instrument. We present PSC results from the Northern Hemisphere 2019–2010 winter/spring season to illustrate the exceptional nature of this season. Future OMPS LP instruments flying on Joint Polar Satellite System (JPSS) satellites will continue PSC observations into the 2030s.
Prima Facie Evidence of the Fast Impact of a Lightning Stroke on the Lower Ionosphere
Authors: Qin Zilong , Chen Mingli , Lyu Fanchao , Cummer Steven A. , Gao Yan , Liu Feifan , Zhu Baoyou , Du Ya‐ping , Usmani Asif , Qiu Zongxu
Published: October 2020

Studies show that intense lightning discharges can perturb nighttime lower ionosphere through induced electromagnetic fields. We report here new evidence that every lightning stroke, regardless of intensity, has an impact on both daytime and nighttime lower ionosphere. Through analysis of thousands of negative cloud‐to‐ground lightning strokes in southern China, we find that skywave features of a lightning sferic are closely related to its source intensity. Variations with increasing lightning intensity show a higher reflectivity from nighttime ionosphere but a larger time delay from daytime ionosphere. It also shows that the ionosphere recovers from the lightning impact in a time shorter than tens of milliseconds. This suggests that there exists a direct and fast nonlinear coupling between lightning‐generated electromagnetic fields and lower ionosphere, making the ionospheric response to a lightning stroke dependent of the lightning intensity. A candidate mechanism for this is the Joule heating effect, but it needs future studies.
A Double Hemispherical Probe for Characterizing and Minimizing the Self‐Wake Effects on Probe Measurements
Authors: Samaniego Joseph I. , Yeo Li Hsia , Wang Xu
Published: October 2020

Space‐borne Langmuir probes generally have a self‐wake behind themselves due to supersonic relative velocities (Mach number M > 1) between the spacecraft and ambient plasma ions. Such a wake may create difficulties for correctly measuring plasma characteristics. Here we present a new technique—the Double Hemispherical Probe (DHP) to characterize and minimize the self‐wake effects on probe measurements. The DHP consists of two hemispheres that are simultaneously swept with a bias voltage to obtain two independent current‐voltage (I‐V) curves, which are used to identify the wake effects of the probe. A laboratory DHP model is inserted in plasma flows (M > 10) created in the Colorado Solar Wind Experiment (CSWE) chamber. In this case, the ion current is the ram current collected by the upstream hemisphere of the DHP, leaving an ion wake behind the downstream hemisphere. A wide range of the Debye ratio RD (ratio of the probe radius to electron Debye length) is tested, and it is found that (1) when RD < 1, the electron currents collected by the two hemispheres are similar, indicating a uniform electron density around the probe, and (2) when RD > 1, the electron current collected by the downstream hemisphere becomes lower than the upstream, indicating a reduced electron density in the probe's wake due to the ambipolar electric field effect. In this case, the electron density measured by traditional single Langmuir probes will be underestimated. With the DHP, we can use the upstream hemisphere measurements to minimize the self‐wake effects.
An Assessment of the Temporal Variability in the Annual Cycle of Daily Antarctic Sea Ice in the NCAR Community Earth System Model, Version 2: A Comparison of the Historical Runs With Observations
Authors: Raphael Marilyn N. , Handcock Mark S. , Holland Marika M. , Landrum Laura L.
Published: October 2020

Understanding the variability of Antarctic sea ice is an ongoing challenge given the limitations of observed data. Coupled climate model simulations present the opportunity to examine this variability in Antarctic sea ice. Here, the daily sea ice extent simulated by the newly released National Center for Atmospheric Research (NCAR) Community Eart h System Model Version 2 (CESM2) for the historical period (1979–2014) is compared to the satellite‐observed daily sea ice extent for the same period. The comparisons are made using a newly developed suite of statistical metrics that estimates the variability of the sea ice extent on timescales ranging from the long‐term decadal to the short term, intraday scales. Assessed are the annual cycle, trend, day‐to‐day change, and the volatility, a new statistic that estimates the variability at the daily scale. Results show that the trend in observed daily sea ice is dominated by subdecadal variability with a weak positive linear trend superimposed. The CESM2 simulates comparable subdecadal variability but with a strong negative linear trend superimposed. The CESM2's annual cycle is similar in amplitude to the observed, key differences being the timing of ice advance and retreat. The sea ice begins its advance later, reaches its maximum later and begins retreat later in the CESM2. This is confirmed by the day‐to‐day change. Apparent in all of the sea ice regions, this behavior suggests the influence of the semiannual oscillation of the circumpolar trough. The volatility, which is associated with smaller scale dynamics such as storms, is smaller in the CESM2 than observed.
Stable Oxygen Isotope Composition Is Biased by Shell Calcification Intensity in Planktonic Foraminifera
Authors: Weinkauf M. F. G. , Groeneveld J. , Waniek J. J. , Vennemann T. , Martini R.
Published: October 2020

Planktonic Foraminifera are widely used for environmental reconstructions through measurements of their shell's geochemical characteristics, including its stable oxygen and carbon isotope composition. Using these parameters as unbiased proxies requires a firm knowledge of all potential confounding factors influencing foraminiferal shell geochemistry. One such parameter is the shell calcification intensity (shell weight normalized for shell size) that may influence the shell δ18O value either bioenergetically (by reducing energy available and required for equilibrium isotope fractionation during faster calcification) or kinetically (by influencing calcification depth through the shell's density contrast with seawater). Specimens from the Globigerinoides ruber/elongatus complex from a sediment trap in the North Atlantic have been used to quantify the influence of shell calcification intensity on shell δ18O values. Shell calcification intensity was found to have a significant effect on the shell stable oxygen isotope composition in all species. Through model fitting, it is suggested that the effect size may be in a range of 1‰ to 2‰ (depending on species, depth migration, and local oceanographic conditions). We show that the confounding effect of shell calcification intensity on stable oxygen isotope composition can be of importance, depending on the anticipated precision of the derived reconstructions. A framework is provided to quantify this effect in future studies.
Local Storage Dynamics of Individual Wetlands Predict Wetlandscape Discharge
Authors: Klammler Harald , Quintero Carlos J. , Jawitz James W. , McLaughlin Daniel L. , Cohen Matthew J.
Published: October 2020

Wetlands provide valuable hydrological, ecological, and biogeochemical functions, both alone and in combination with other elements comprising the wetlandscape. Understanding the processes and mechanisms that drive wetlandscape functions, as well as their sensitivity to natural and man‐made alterations, requires a sound physical understanding of wetland hydrodynamics. Here, we develop and apply a single reservoir hydrologic model to a low‐relief karst wetlandscape in southwest Florida (≈103 km2 of Big Cypress National Preserve) using precipitation P and potential evapotranspiration PET as climatic drivers. This simple approach captures the dynamics of storage for individual wetlands across the entire wetlandscape and accurately predicts landscape discharge. Key model insights are the importance of depth‐dependent extinction of evapotranspiration ET and the negligible effects of depth‐dependent specific yield, the effects of which are diluted by landscape relief. We identify three phases of the wetlandscape hydrological regime: dry, wet‐stagnant, and wet‐flowing. The model allowed a simple steady‐state analysis, which demonstrated the sudden seasonal shift between wet‐stagnant and wet‐flowing states, indicating a consistent threshold at P ≈ PET. Notably, stage data from any single wetland appears sufficient for accurate whole‐landscape discharge prediction because of the relative homogeneity in timing and duration of local wetland hydrologic connectivity in this landscape. We also show that this method will be transferable to other wetlandscapes, where individual storage elements respond hydrologically synchronously, whereas model performance is expected to deteriorate for hydrologically more heterogeneous wetlandscapes.
Rainforest-to-pasture conversion stimulates soil methanogenesis across the Brazilian Amazon
Authors: Kroeger Marie E , Meredith Laura K , Meyer Kyle M , Webster Kevin D , de Camargo Plinio Barbosa , de Souza Leandro Fonseca , Tsai Siu Mui , van Haren Joost , Saleska Scott , Bohannan Brendan J M , Rodrigues Jorge L Mazza , Berenguer Erika , Barlow Jos , Nüsslein Klaus
Published: October 2020

The Amazon rainforest is a biodiversity hotspot and large terrestrial carbon sink threatened by agricultural conversion. Rainforest-to-pasture conversion stimulates the release of methane, a potent greenhouse gas. The biotic methane cycle is driven by microorganisms; therefore, this study focused on active methane-cycling microorganisms and their functions across land-use types. We collected intact soil cores from three land use types (primary rainforest, pasture, and secondary rainforest) of two geographically distinct areas of the Brazilian Amazon (Santarém, Pará and Ariquemes, Rondônia) and performed DNA stable-isotope probing coupled with metagenomics to identify the active methanotrophs and methanogens. At both locations, we observed a significant change in the composition of the isotope-labeled methane-cycling microbial community across land use types, specifically an increase in the abundance and diversity of active methanogens in pastures. We conclude that a significant increase in the abundance and activity of methanogens in pasture soils could drive increased soil methane emissions. Furthermore, we found that secondary rainforests had decreased methanogenic activity similar to primary rainforests, and thus a potential to recover as methane sinks, making it conceivable for forest restoration to offset greenhouse gas emissions in the tropics. These findings are critical for informing land management practices and global tropical rainforest conservation.
Autotrophic and mixotrophic metabolism of an anammox bacterium revealed by in vivo 13C and 2H metabolic network mapping
Authors: Lawson Christopher E , Nuijten Guylaine H L , de Graaf Rob M , Jacobson Tyler B , Pabst Martin , Stevenson David M , Jetten Mike S M , Noguera Daniel R , McMahon Katherine D , Amador-Noguez Daniel , Lücker Sebastian
Published: October 2020

Anaerobic ammonium-oxidizing (anammox) bacteria mediate a key step in the biogeochemical nitrogen cycle and have been applied worldwide for the energy-efficient removal of nitrogen from wastewater. However, outside their core energy metabolism, little is known about the metabolic networks driving anammox bacterial anabolism and use of different carbon and energy substrates beyond genome-based predictions. Here, we experimentally resolved the central carbon metabolism of the anammox bacterium Candidatus ‘Kuenenia stuttgartiensis’ using time-series 13C and 2H isotope tracing, metabolomics, and isotopically nonstationary metabolic flux analysis. Our findings confirm predicted metabolic pathways used for CO2 fixation, central metabolism, and amino acid biosynthesis in K. stuttgartiensis, and reveal several instances where genomic predictions are not supported by in vivo metabolic fluxes. This includes the use of the oxidative branch of an incomplete tricarboxylic acid cycle for alpha-ketoglutarate biosynthesis, despite the genome not having an annotated citrate synthase. We also demonstrate that K. stuttgartiensis is able to directly assimilate extracellular formate via the Wood–Ljungdahl pathway instead of oxidizing it completely to CO2 followed by reassimilation. In contrast, our data suggest that K. stuttgartiensis is not capable of using acetate as a carbon or energy source in situ and that acetate oxidation occurred via the metabolic activity of a low-abundance microorganism in the bioreactor’s side population. Together, these findings provide a foundation for understanding the carbon metabolism of anammox bacteria at a systems-level and will inform future studies aimed at elucidating factors governing their function and niche differentiation in natural and engineered ecosystems.
Amitriptyline interferes with autophagy-mediated clearance of protein aggregates via inhibiting autophagosome maturation in neuronal cells
Authors: Kwon Yoonjung , Bang Yeojin , Moon Soung-Hee , Kim Aeri , Choi Hyun Jin
Published: October 2020

Amitriptyline is a tricyclic antidepressant commonly prescribed for major depressive disorders, as well as depressive symptoms associated with various neurological disorders. A possible correlation between the use of tricyclic antidepressants and the occurrence of Parkinson’s disease has been reported, but its underlying mechanism remains unknown. The accumulation of misfolded protein aggregates has been suggested to cause cellular toxicity and has been implicated in the common pathogenesis of neurodegenerative diseases. Here, we examined the effect of amitriptyline on protein clearance and its relevant mechanisms in neuronal cells. Amitriptyline exacerbated the accumulation of abnormal aggregates in both in vitro neuronal cells and in vivo mice brain by interfering with the (1) formation of aggresome-like aggregates and (2) autophagy-mediated clearance of aggregates. Amitriptyline upregulated LC3B-II, but LC3B-II levels did not increase further in the presence of NH4Cl, which suggests that amitriptyline inhibited autophagic flux rather than autophagy induction. Amitriptyline interfered with the fusion of autophagosome and lysosome through the activation of PI3K/Akt/mTOR pathway and Beclin 1 acetylation, and regulated lysosome positioning by increasing the interaction between proteins Arl8, SKIP, and kinesin. To the best of our knowledge, we are the first to demonstrate that amitriptyline interferes with autophagic flux by regulating the autophagosome maturation during autophagy in neuronal cells. The present study could provide neurobiological clue for the possible correlation between the amitriptyline use and the risk of developing neurodegenerative diseases.
Cardiomyocyte-restricted high-mobility group box 1 (HMGB1) deletion leads to small heart and glycolipid metabolic disorder through GR/PGC-1α signalling
Authors: Yu Peng , Liu Ming , Zhang Baoli , Yu Ying , Su Enyong , Xie Shiyao , Zhang Lei , Yang Xue , Jiang Hong , Chen Ruizhen , Zou Yunzeng , Ge Junbo
Published: October 2020

Cardiac growth and remodelling are key biological processes influencing the physiological performance of the heart, and a previous study showed a critical role for intracellular HMGB1 in vitro. However, the in vivo study, which used conditional Hmgb1 ablation, did not show a significant effect on cellular or organic function. We have demonstrated the extracellular effect of HMGB1 as a pro-inflammatory molecule on cardiac remodelling. In this study, we found that HMGB1 deletion by cTnT-Cre in mouse hearts altered glucocorticoid receptor (GR) function and glycolipid metabolism, eventually leading to growth retardation, small heart and heart failure. The subcellular morphology did not show a significant change caused by HMGB1 knockout. The heart showed significant elevation of glycolysis, free fatty acid deposition and related enzyme changes. Transcriptomic analysis revealed a list of differentially expressed genes that coincide with glucocorticoid receptor function in neonatal mice and a significant increase in inflammatory genes in adult mice. Cardiac HMGB1 knockout led to a series of changes in PGC-1α, UCP3 and GyK, which were the cause of metabolic changes and further impacted cardiac function. Ckmm-Cre Hmgb1fl/flmice did not show a specific phenotype, which was consistent with the reported negative result of cardiomyocyte-specific Hmgb1 deletion via MHC-Cre. We concluded that HMGB1 plays essential roles in maintaining normal cardiac growth, and different phenotype from cardiac-specific HMGB1-deficient mice may be caused by the cross with mice of different Cre strains.