bluuebunny/crossref_metadata_2025 huggingface dataset:
Negotiating Ethics-in-Action in a Long-term Research Relationship with a Young Child
Authors: Rutanen Niina , Raittila Raija , Harju Kaisa , Lucas Revilla Yaiza , Hännikäinen Maritta
Published: April 2021

This article continues the discussions of relational ethics put forward in Human Arenas in “Arena of Ethics” (Hilppö et al., 2019). Our aim in this article is to explore and discuss relational ethics, as ethics-in-action, in a long-term research relationship with a child. Our question is: How is ethics-in-action negotiated during critical incidents in the construction of a research space that involves a long-term research relationship with a young child? This article is based on a research project that focused on children’s transitions in early childhood education and care (ECEC). These transitions include the transition from home care to ECEC as well as transitions from child groups or settings to other ECEC groups or settings, and the transition to pre-primary education. We apply a particular lens to the corpus of data, analyzing and reflecting critical incidents vis-à-vis a negotiation of ethics-in-action during the construction of our research space, which involved a long-term research relationship with a child. Our results show that critical incidents in our study’s negotiation of ethics-in-action included (a) the focus child’s spontaneous contributions to the study’s interviews, (b) interdependencies between the child and diverse researchers, and (c) the child’s evolving expertise in data collection, which restructured our study’s research space. We conclude that ethical questions cannot be separated from the mutually constituted relationships or socio-spatial context in where they emerge; thus, they are relationally and spatially embedded.
Bias-inducing allosteric binding site in mu-opioid receptor signaling
Authors: Marmolejo-Valencia Andrés F. , Madariaga-Mazón Abraham , Martinez-Mayorga Karina
Published: April 2021

G-protein-biased agonism of the mu-opioid receptor (μ-OR) is emerging as a promising strategy in analgesia. A deep understanding of how biased agonists modulate and differentiate G-protein-coupled receptors (GPCR) signaling pathways and how this is transferred into the cell are open questions. Here, using extensive all-atom molecular dynamics simulations, we analyzed the binding recognition process and signaling effects of three prototype μ-OR agonists. Our suggested structural mechanism of biased signaling in μ-OR involves an allosteric sodium ion site, water networks, conformational rearrangements in conserved motifs and collective motions of loops and transmembrane helices. These analyses led us to highlight the relevance of a bias-inducing allosteric binding site in the understanding of μ-OR’s G-protein-biased signaling. These results also suggest a competitive equilibrium between the agonists and the allosteric sodium ion, where the bias-inducing allosteric binding site can be modulated by this ion or an agonist such as herkinorin. Notably, herkinorin arises as the archetype modulator of μ-OR and its interactive pattern could be used for screening efforts via protein–ligand interaction fingerprint (PLIF) studies.

Article highlights

Agonists and a sodium ion compete for the bias-inducing allosteric binding site that modulates signaling in mu-opioid receptors.

Molecular dynamics simulations of the prototype μ-OR agonist suggest a competitive equilibrium involving the agonist and an allosteric sodium ion.

Analysis of experimental data from the literature and molecular models provides the structural bases of biased agonism on μ-OR.
A Wavelet-Free Approach for Multiresolution-Based Grid Adaptation for Conservation Laws
Authors: Gerhard Nils , Müller Siegfried , Sikstel Aleksey
Published: April 2021

In recent years the concept of multiresolution-based adaptive discontinuous Galerkin (DG) schemes for hyperbolic conservation laws has been developed. The key idea is to perform a multiresolution analysis of the DG solution using multiwavelets defined on a hierarchy of nested grids. Typically this concept is applied to dyadic grid hierarchies where the explicit construction of the multiwavelets has to be performed only for one reference element. For non-uniform grid hierarchies multiwavelets have to be constructed for each element and, thus, becomes extremely expensive. To overcome this problem a multiresolution analysis is developed that avoids the explicit construction of multiwavelets.
A versatile heterogeneous photocatalyst: nanoporous gold powder modified with a zinc(II) phthalocyanine derivative for singlet oxygen [4 + 2] cycloadditions
Authors: Steinebrunner David , Schnurpfeil Günter , Doebler Hans Hannes , Tapia Burgos Jorge Adrian , Wöhrle Dieter , Wittstock Arne
Published: April 2021

Nanoporous gold was functionalized with a photosensitizer, a zinc(II) phthalocyanine derivative. Such systems are active for the generation of reactive singlet oxygen which can be used for photocatalytic oxidation reactions. This study aims to demonstrate the versatility of such an approach, in terms of substrates and the employed solvent, only possible for a truly heterogeneous catalytic system. The activity of the hybrid system was studied for [4 + 2] cycloadditions of three different types of dienes and a total of eight substrates in two organic solvents and once in water. The highest activity was measured for 1,3-diphenylisobenzofuran, which is also highest in terms of sensitivity for the reaction with 1O2. Trends in conversion could be anticipated based on reported values for the rate constant for the reaction of 1O2. In almost all cases, an amplification of the conversion by immobilization of the sensitizer onto nanoporous gold was observed. The limiting case was ergosterol, which was the largest of all substrates with a van-der-Waals radius of about 2.1 nm. Additional factors such as the limited lifetime of 1O2 in different solvents as well as the hampered diffusion of the substrates were identified.

Graphic abstract
A Short History of Shakespeare in Performance
Authors: Schoch Richard
Published: April 2021

This short history of Shakespeare in global performance-from the re-opening of London theatres upon the restoration of the monarchy in 1660 to our present multicultural day-provides a comprehensive overview of Shakespeare's theatrical afterlife and introduces categories of analysis and understanding to make that afterlife intellectually meaningful. Written for both the advanced student and the practicing scholar, this work enables readers to situate themselves historically in the broad field of Shakespeare performance studies and equips them with analytical tools and conceptual frameworks for making their own contributions to the field.
Bilingual Development in Childhood
Authors: De Houwer Annick
Published: April 2021

In the first decade of life, children become bilingual in different language learning environments. Many children start learning two languages from birth (Bilingual First Language Acquisition). In early childhood hitherto monolingual children start hearing a second language through daycare or preschool (Early Second Language Acquisition). Yet other hitherto monolingual children in middle childhood may acquire a second language only after entering school (Second Language Acquisition). This Element explains how these different language learning settings dynamically affect bilingual children's language learning trajectories. All children eventually learn to speak the societal language, but they often do not learn to fluently speak their non-societal language and may even stop speaking it. Children's and families' harmonious bilingualism is threatened if bilingual children do not develop high proficiency in both languages. Educational institutions and parental conversational practices play a pivotal role in supporting harmonious bilingual development.
Appeal Relating to the Jurisdiction of the ICAO Council
Authors: Rose Cecily
Published: April 2021

In two nearly identical judgments dated July 14, 2020, the International Court of Justice (ICJ or Court) reviewed a decision taken by the Council of the International Civil Aviation Organization (ICAO) in a dispute about aviation restrictions imposed on Qatar by Bahrain, Egypt, Saudi Arabia, and the United Arab Emirates (UAE). These cases represent the second time that the Court has heard an appeal concerning a decision of the ICAO Council, a treaty body which has executive, administrative, and dispute settlement functions. As in 1972, when the Court heard an appeal brought by India against Pakistan, the Court's 2020 judgments concern a Council decision on preliminary objections to jurisdiction and admissibility. These judgments not only reinforce the ICJ's findings in its 1972 judgment, which raised similar procedural issues, but they also highlight the scope and the limits of the Court's rare appellate function.
India Fighting COVID-19: Experiences and Lessons Learned From the Successful Kerala and Bhilwara Models
Authors: Chandra Rishita , Sinha Smita
Published: April 2021

The COVID-19 pandemic marks its emergence in China in December 2019. India reported its first case on January 30th 2020 which happened to be epidemiologically linked to China. On March 24, India went into nationwide lockdown. The number of cases increased in the country and a few hotspots were identified. Cluster containment strategy seemed to be effective in containing the disease and breaking the chain of transmission. Two models (Kerala and Bhilwara) emerged as a lesson for other states. Kerala government implemented a “triple-lock containment strategy” and Bhilwara district administration followed “all down curfew” with massive sample testing. The experiences from these successful field models can be implemented in other districts and states to flatten the COVID-19 curve.
Mary Parker Follett as Integrative Public Philosopher
Authors: Brown Matthew J.
Published: April 2021

Mary Parker Follett was a feminist-pragmatist American philosopher, a social-settlement worker, a founding figure in the community centers movement, a mediator of labor disputes, and a theorist of political and social organization and management. I argue that she is a model for a certain kind of public philosopher, and I unpack the respects in which she serves as such a model. I emphasize both her virtues as a public thinker and the role played in her work by the process of integration and the creative process.
The role of procalcitonin results in antibiotic decision-making in coronavirus disease 2019 (COVID-19)
Authors: Fabre Valeria , Karaba Sara , Amoah Joe , Robinson Matthew , Jones George , Dzintars Kathryn , Katz Morgan , Landrum B. Mark , Qasba Sarojini , Gupta Pooja , Klein Eili , Cosgrove Sara E.
Published: April 2021

Objective:

To evaluate the role of procalcitonin (PCT) results in antibiotic decisions for COVID-19 patients at hospital presentation.

Design, setting, and participants:

Multicenter retrospective observational study of patients ≥18 years hospitalized due to COVID-19 at the Johns Hopkins Health system. Patients who were transferred from another facility with >24 hours stay and patients who died within 48 hours of hospitalization were excluded.

Methods:

Elevated PCT values were determined based on each hospital’s definition. Antibiotic therapy and PCT results were evaluated for patients with no evidence of bacterial community-acquired pneumonia (bCAP) and patients with confirmed, probable, or possible bCAP. The added value of PCT testing to clinical criteria in detecting bCAP was evaluated using receiving operating curve characteristics (ROC).

Results:

Of 962 patients, 611 (64%) received a PCT test. ROC curves for clinical criteria and clinical criteria plus PCT test were similar (at 0.5 ng/mL and 0.25 ng/mL). By bCAP group, median initial PCT values were 0.58 ng/mL (interquartile range [IQR], 0.24–1.14), 0.23 ng/mL (IQR, 0.1–0.63), and 0.15 ng/mL (IQR, 0.09–0.35) for proven/probable, possible, and no bCAP groups, respectively. Among patients without bCAP, an elevated PCT level was associated with 1.8 additional days of CAP therapy (95% CI, 1.01–2.75; P < .01) compared to patients with a negative PCT result after adjusting for potential confounders. Duration of CAP therapy was similar between patients without a PCT test ordered and a low PCT level for no bCAP and possible bCAP groups.

Conclusions:

PCT results may be abnormal in COVID-19 patients without bCAP and may result in receipt of unnecessary antibiotics.
Droplet motion and oscillation on contrasting micro-striated surfaces
Authors: Zhao Hongyu , Orejon Daniel , Sefiane Khellil , Shanahan Martin E.R.
Published: April 2021

Spontaneous motion of liquid droplets can occur on hydrophobic, micro-structured, solid surfaces comprising a structural gradient. In this study, we examine such motion experimentally and explain our observations by invoking variable droplet–surface interactions (both actuation and resistance forces) arising from the structural gradient. The oscillatory motion of the droplet constitutes an integral aspect of the behaviour and this is incorporated into the overall modelling. The theoretical model features a truncated spheroid for the drop shape (flattened in the region of solid contact) coupled with the oscillatory and alternate leading and trailing motion of the contact line. Results from the model and experiments provide good qualitative and quantitative agreement. The component of the vertical oscillation is found to help overcome wetting hysteresis and actuate the motion, this being a key element for the completeness of the model.
An outer shelf shelly fauna from Cambrian Series 2 (Stage 4) of North Greenland (Laurentia)
Authors: Peel John S.
Published: April 2021

An assemblage of 50 species of small shelly fossils is described from Cambrian Series 2 (Stage 4) strata in North Greenland, the present day northernmost part of the paleocontinent of Laurentia. The fossils are derived from the basal member of the Aftenstjernesø Formation at Navarana Fjord, northern Lauge Koch Land, a condensed unit that accumulated in a sediment-starved outer ramp setting in the transarctic Franklinian Basin, on the Innuitian margin of Laurentia. Most other small shelly fossil assemblages of similar age and composition from North America are described from the Iapetan margin of Laurentia, from North-East Greenland south to Pennsylvania. Trilobites are uncommon, but includeSerrodiscus. The Australian bradoriidSpinospitellais represented by a complete shield.Obolella crassais the only common brachiopod. Hyoliths, includingCassitella,Conotheca,Neogloborilus, andTriplicatella, are abundant and diverse, but most are represented just by opercula. Sclerites interpreted as stem-group aculiferans (sachitids) are conspicuous, includingQaleruaqia, the oldest described paleoloricate,Ocruranus?,Inughuitoconusn. gen., andHippopharangites. Helcionelloid mollusks are diverse, but not common; they are associated with numerous specimens of the bivalvePojetaia runnegari. The fauna compares best with that of the upper Bastion Formation of North-East Greenland, the Forteau Formation of western Newfoundland, and the Browns Pond Formation of New York, but several taxa have a world-wide distribution. Many specimens are encrusted with crystals of authigenic albite. New species:Anabarella?navaranae,Stenotheca?higginsi,Figurina?polaris,Hippopharangites groenlandicus,Inughuitoconus borealis, andOcruranus?kangerluk.

UUID:http://zoobank.org/160a17b1-3166-4fcf-9849-a3cabd1e04a3
Victims of Compromise: The Elizabethan Psalm Tunes
Authors: TEMPERLEY NICHOLAS
Published: April 2021

The music of The Whole Book of Psalms (first printed in 1562) was not a product of English tradition, but a new congregational system brought home from Geneva. Psalm tunes in Edward VI’s time had been secular, iambic and based on dance rhythms; in so far as Thomas Sternhold’s metrical psalms were sung in church, they were chanted by choirs to Sarum tones. The tunes created for congregational use by the Marian exiles had to satisfy Calvin’s principle that they must be distinct from secular songs. They avoided strong rhythms and imitated the Huguenot psalter, which catered for a very different French prosody. Elizabethan congregations were enthusiastic about singing, but did not take to many of these tunes. Evidence shows a growing tendency for the printed tunes to be ignored in practice, and to be replaced by orally transmitted ‘common tunes’ restoring the secular Edwardian idiom. These, rather than the Elizabethan tunes, became the lasting model for the English hymn tune.
On the accuracy of the binary-collision algorithm in particle-in-cell simulations of magnetically confined fusion plasmas
Authors: Kiviniemi Timo P. , Hirvijoki Eero , Virtanen Antti J.
Published: April 2021

Ideally, binary-collision algorithms conserve kinetic momentum and energy. In practice, the finite size of collision cells and the finite difference in the particle locations affect the conservation properties. In the present work, we investigate numerically how the accuracy of these algorithms is affected when the size of collision cells is large compared with gradient scale length of the background plasma, a parameter essential in full-

$f$

fusion plasma simulations. Additionally, we discuss implications for the conserved quantities in drift-kinetic formulations when fluctuating magnetic and electric fields are present: we suggest how the accuracy of the algorithms could potentially be improved with minor modifications.
Processing of infant emotion in mothers with mood disorders and implications for infant development
Authors: Bjertrup Anne J. , Moszkowicz Mala , Egmose Ida , Kjærbye-Thygesen Anette , Nielsen René E. , Parsons Christine E. , Kessing Lars V. , Pagsberg Anne Katrine , Væver Mette S. , Miskowiak Kamilla W.
Published: April 2021

Background

Atypical neurocognitive responses to emotional stimuli are core features of unipolar depression (UD) and bipolar disorder (BD). For mothers with these mood disorders, this may influence interactions with their infants and consequently infant development. The study aimed to investigate psychophysiological and cognitive responses to infant emotional stimuli, and their relation to mother–infant interaction and infant development, in mothers with BD or UD in full or partial remission.

Methods

Four months after birth, mothers' cognitive responses to emotional infant stimuli were assessed with computerized tasks, while their facial expressions, galvanic skin responses (GSR), gazes, and fixations were recorded. Infant development and mother–infant interactions were also assessed.

Results

We included 76 mothers: 27 with BD, 13 with UD, and 36 without known psychiatric disorders, and their infants. Mothers with BD and UD were in full or partial remission and showed blunted GSR and spent less time looking at infant stimuli (unadjustedpvalues < 0.03). Mothers with BD showed subtle positive neurocognitive biases (unadjustedpvalues<0.04) and mothers with UD showed negative biases (unadjustedpvalues < 0.02). Across all mothers, some measures of atypical infant emotion processing correlated with some measures of delays in infant development and suboptimal mother–infant interaction (unadjustedpvalues<0.04).

Conclusions

Mothers with mood disorders in full or partial remission showed atypical cognitive and psychophysiological response to emotional infant stimuli, which could be associated with mother–infant interactions and infant development. The study is explorative, hypothesis generating, and should be replicated in a larger sample. Investigation of the long-term implications of reduced maternal sensitivity is warranted.
Accountability through public participation? Experiences from the ten-thousand-citizen review in Nanjing, China
Authors: Li Yanwei , Qin Xiaolei , Koppenjan Joop
Published: April 2021

In this contribution, we report on an in-depth case study of the ten-thousand-citizen review in Nanjing, an initiative to deal with the accountability deficit with which many Chinese governments have to cope. Nanjing Municipality invited citizens to evaluate officials’ performance, and their reviews influenced the scores of officials’ remunerations and even their careers. On the basis of theory, in this study, we develop a typology that is used to analyse how the introduction of this new horizontal practice of “letting citizens judge” influenced the existing accountability relations and how these relationships evolved over time. Our findings show that citizens’ involvement initially resulted in a practice in which types of accountability were mixed and resulted in a situation of multiple accountabilities disorder. Only gradually were accountability characteristics aligned and the accountability deficit and overload reduced. This demonstrates the difficulties and challenges of introducing horizontal accountability arrangements in existing accountability systems.
Crack and Criminal Justice in Canton, Ohio, 1987–1999: “The Drug Problem has Created a Monster”
Authors: COOLEY WILL
Published: April 2021

The rise of crack cocaine in the late 1980s propelled the war on drugs. The experience of Canton, Ohio, shows how the response to crack solidified mass incarceration. A declining industrial city of 84,000 people in northeast Ohio with deep-seated racial divides, it was overwhelmed by aggressive, enterprising crack dealers from outside the city. In response, politicians and residents united behind the strategy of incessant arrests and drastic prison sentences. The law-enforcement offensive worsened conditions while pursuing African Americans at blatantly disproportionate rates, but few people engaged in reframing the drug problem. Instead, a punitive citizenry positioned punishment as the principal remedy. The emergency foreclosed on more comprehensive assessments of the city’s tribulations, while the criminal justice system emerged as the paramount institution.
Expanding the limits of sex: a systematic review concerning food and nutrition in transgender populations
Authors: Gomes Sávio Marcelino , Jacob Michelle CM , Rocha Cecília , Medeiros Maria FA , Lyra Clélia O , Noro Luiz RA
Published: April 2021

Objective:

To examine the literature and identify main themes, methods and results of studies concerning food and nutrition addressed in research on transgender populations.

Design:

A systematic review conducted through July 2020 in the MedLine/PubMed, Scopus and Web of Science databases.

Results:

Of the 778 studies identified in the databases, we selected thirty-seven. The studies were recent, most of them published after 2015, being produced in Global North countries. The most often used study design was cross-sectional; the least frequently used study design was ethnographic. Body image and weight control were predominant themes (n25), followed by food and nutrition security (n5), nutritional status (n5), nutritional health assistance (n1) and emic visions of healthy eating (n1).

Conclusions:

The transgender community presents body, food and nutritional relationships traversed by its unique gender experience, which challenges dietary and nutritional recommendations based on the traditional division by sex (male and female). We need to complete the lacking research and understand contexts in the Global South, strategically investing in exploratory-ethnographic research, to develop categories of analysis and recommendations that consider the transgender experience.
Fluid Enquiry, Complex Causality, Policy Processes: Making a Difference with Qualitative Longitudinal Research
Authors: Neale Bren
Published: April 2021

In this article, qualitative longitudinal (QL) research is presented as a powerful form of fluid enquiry. The combination of its real-world and real-time features enables this methodology to ‘follow reality in all its windings’, and, thereby, to produce useful knowledge for policy and professional practice. The main focus is on the power of QL methodology to illuminate complex causal processes by teasing out their multiple, fluid and relational elements. The article goes on to consider new ways to broker the interface between research endeavours and policy processes, based on collaborative modes of knowledge co-production that unfold in real-time. QL enquiry emerges here as more than an added option, a ‘niche’ approach. It has potential as a valuable ‘impact’ tool for discerning causality in new ways and reformulating insights into ‘what works?’, with scope to play a pivotal role in shaping and facilitating change in policy and practice settings.
Diseases of Johnsongrass (Sorghum halepense): possible role as a reservoir of pathogens affecting other plants
Authors: Ahn Ezekiel , Prom Louis K. , Magill Clint
Published: April 2021

Johnsongrass [Sorghum halepense (L.) Pers.] is one of the most noxious weeds distributed around the world. Due to its rapid growth, wide dissemination, seeds that can germinate after years in the soil, and ability to spread via rhizomes, S. halepense is difficult to control. From a perspective of plant pathology, S. halepense is also a potential reservoir of pathogens that can eventually jump to other crops, especially corn (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench]. As one of the most problematic weeds, S. halepense and its diseases can provide useful information concerning its role in diseases of agronomically important crops. An alternative consideration is that S. halepense may provide a source of genes for resistance to pathogens. While some studies have verified that pathogens isolated from S. halepense actually cause disease on host crops through cross inoculation, similarity of disease symptoms and pathogen morphology have been used for identity of the disease agent in most studies. Availability of DNA sequence information has greatly altered and improved pathogen identification, leading to significant changes in phylogenetic assignments. Reclassification of pathogens, especially fungi, raises new questions concerning the role of S. halepense as a disease reservoir. Our goals in this review are to pinpoint, where possible, diseases for which S. halepense acts as a significant pathogen reservoir and to point out problem areas where further research is needed.
Dating Lake Sediments Using Compound‐Specific 14C Analysis of C16 Fatty Acid: A Case Study From the Mount Fuji Volcanic Region, Japan
Authors: Yamamoto Shinya , Nishizawa Fumikatsu , Yoshimoto Mitsuhiro , Miyairi Yosuke , Yokoyama Yusuke , Suga Hisami , Ohkouchi Naohiko
Published: April 2021

Lake sediments in volcanic regions contain continuous records of past eruptions and their environmental consequences. However, the frequent scarcity of plant material in lake sediments makes it difficult to provide robust age estimates. In this study, we performed compound‐specific radiocarbon analysis (CSRA) of fatty acids in a sediment core from Lake Kawaguchi in the Mount Fuji volcanic region, Japan, to assess their potential for dating sediments. The C16 fatty acid in the core top sediments exhibits an almost identical age (983 ± 56 years BP) to that of dissolved inorganic carbon in the modern lake surface water, which confirms that the carbon of this compound is derived from lake phytoplankton. Comparison of the 14C age between the C16 fatty acid and a plant leaf at the widespread (Amagi‐Kawagodaira) tephra layer revealed a lake reservoir age of 1,003 ± 73 14C years at ca. 3,150 cal BP, which is consistent with the modern lake reservoir age and the 14C age of the C16 fatty acid in the core top sediments, within error. The reservoir‐corrected 14C age of the C16 fatty acid yielded a modeled age of 2,837 ± 78 cal BP for the Mount Fuji Tephra (Omuro scoria‐fall deposit) in the core. This age is in good agreement with the age determined from plant remains in the same core (2,938 ± 29 cal BP), indicating that CSRA of C16 fatty acid has the potential to date lake sediments after reservoir age correction, even in sediments with limited occurrence of plant macrofossils.
Opposite Responses of the Dry and Moist Eddy Heat Transport Into the Arctic in the PAMIP Experiments
Authors: Audette Alexandre , Fajber Robert A. , Kushner Paul J. , Wu Yutian , Peings Yannick , Magnusdottir Gudrun , Eade Rosie , Sigmond Michael , Sun Lantao
Published: April 2021

Given uncertainty in the processes involved in polar amplification, elucidating the role of poleward heat and moisture transport is crucial. The Polar Amplification Model Intercomparison Project (PAMIP) permits robust separation of the effects of sea ice loss from sea surface warming under climate change. We utilize a moist isentropic circulation framework that accounts for moisture transport, condensation, and eddy transport, in order to analyze the circulation connecting the mid‐latitudes and the Arctic. In PAMIP's atmospheric general circulation model experiments, prescribed sea ice loss reduces poleward heat transport (PHT) by warming the returning moist isentropic circulation at high latitudes, while prescribed warming of the ocean surface increases PHT by strengthening the moist isentropic circulation. Inter‐model spread of PHT into the Arctic reflects the tug‐of‐war between sea‐ice and surface‐warming effects.
Non‐Detection of Lightning During the Second Parker Solar Probe Venus Gravity Assist
Authors: Pulupa Marc , Bale Stuart D. , Curry Shannon M. , Farrell William M. , Goodrich Katherine A. , Goetz Keith , Harvey Peter R. , Malaspina David M. , Raouafi Nour E.
Published: April 2021

The Parker Solar Probe (PSP) spacecraft completed its second Venus gravity assist maneuver (VGA2) on December 26, 2019. For a 20 min interval surrounding closest approach, the PSP/FIELDS Radio Frequency Spectrometer (RFS) was set to “burst mode,” recording radio spectra from 1.3 to 19.2 MHz at sub‐second cadence. We analyze this burst mode data, searching for signatures of radio frequency “sferic” emission from lightning discharges. During the burst mode interval, only four spectra were observed with strong impulsive signals, and all four could be attributed to saturation of the RFS high gain stage by in situ electrostatic plasma waves. These RFS measurements during VGA2 are consistent with previous non‐detection of radio frequency lightning signals from Venus reported by Gurnett et al. (2001, https://doi.org/10.1038/35053009).
Seasonal Predictability of Global and North American Coastal Sea Surface Temperature and Height Anomalies
Authors: Shin Sang‐Ik , Newman Matthew
Published: April 2021

A Linear Inverse Model (LIM) is constructed to evaluate predictability of seasonal sea surface temperature (SST) and sea surface height (SSH) anomalies over the ice‐free global ocean. Its ensemble‐mean hindcast skill is also compared to that of the North American Multi‐Model Ensemble (NMME) for 1982–2010. Both have similar skill for dominant modes of SST variability, but regional NMME SST skill is somewhat higher in many locations. However, the LIM has considerably more Atlantic and Southern Ocean SSH skill. Skill is generally comparable along the North American coastline, but LIM skill is greater for several highly productive coastal zones and East Coast tide gauge stations. Diverse, often predictable ENSO events drive teleconnections providing predictability in the North Pacific and along the US West Coast. Predictability in the Atlantic and along the US East Coast is associated with Gulf Stream strength modulation. Overall, the LIM shows potential for seasonal prediction of coastal ocean conditions.
Distinct Carbonate Lithologies in Jezero Crater, Mars
Authors: Zastrow Allison M. , Glotch Timothy D.
Published: April 2021

Jezero crater is the landing site for the Mars 2020 Perseverance rover. The Noachian‐aged crater has undergone several periods of fluvial and lacustrine activity and phyllosilicate‐ and carbonate‐bearing rocks were formed and emplaced as a result. It also contains a portion of the regional Nili Fossae olivine‐carbonate unit. In this work, we performed spectral mixture analysis of visible/near‐infrared hyperspectral imagery over Jezero. We modeled carbonate abundances up to ∼35% and identified three distinct units containing different carbonate phases. Our work also shows that the olivine in Jezero is predominantly restricted to aeolian deposits overlying the carbonate rocks. The diversity of carbonate phases in Jezero points to multiple periods of carbonate formation under varying conditions.
Superconducting Receiver Technologies Supporting ALMA and Future Prospects
Authors: Uzawa Y. , Fujii Y. , Kojima T. , Kroug M. , Shan W. , Ezaki S. , Miyachi A. , Kiuchi H. , Gonzalez A.
Published: April 2021

This paper describes the development of superconductor–insulator–superconductor (SIS) receivers in the 787–950 GHz radio frequency (RF) range, which covers the highest frequency band of the Atacama Large Millimeter/submillimeter Array (ALMA) and is recognized as the most difficult band in terms of superconducting technology, because the conventional superconducting material of Nb cannot be used for the circuitry in the mixer devices at the frequencies. The development began at the National Astronomical Observatory of Japan (NAOJ) in 2005, and the manufacturing and testing of all the receivers to be installed in the 66 Cassegrain reflector antennas that compose ALMA was completed in 2013. This enabled the terahertz frequency observations with the highest sensitivity from the ground. To meet the stringent ALMA requirements, terahertz SIS mixers with high‐quality superconducting NbTiN films were developed, which successfully demonstrated an unpreceded noise performance less than 230 K (5 times the quantum noise) for all the receivers. After the construction of ALMA, NAOJ began development studies for ALMA enhancement such as wideband and multibeam SIS receivers according to top‐level science requirements. To increase instantaneous bandwidth of the receivers, a submillimeter‐wave multiband receiver concept with a waveguide multiplexer, wideband intermediate frequency SIS‐mixer‐amplifier, and multifrequency local oscillator (LO) source is presented. The multibeam receiver employs a planar‐integrated SIS mixer circuit that includes all the RF components except the LO distribution network and an SIS‐mixer‐based amplifier of low power consumption, which is expected to enable the wide field‐of‐view observations in the future.
Extension Discrepancy of the Hyper‐Thinned Continental Crust in the Baiyun Rift, Northern Margin of the South China Sea
Authors: Zhao Yanghui , Ding Weiwei , Ren Jianye , Li Jiabiao , Tong Dianjun , Zhang Jiangyang
Published: April 2021

At rifted continental margins, it has been widely reported that the amount of extension measured from faulting is less than the one observed from crustal and lithospheric thinning, referred to as “extension discrepancy.” Here, we use observations from high‐resolution seismic reflection data over the Baiyun Rift to explore the discrepancy between upper and whole crustal thinning factors when the crust of the Northern South China Sea margin thinned from 30 to <10 km. We first restore the rift system of the Baiyun Rift in the absence of post‐rift sediments and water loading. Subsequently, we calculate thinning factors based on fault geometries and crustal thickness ratios to compare the deformation of the upper and whole crust. Our results show (1) in the eastern and western basins, upper crustal thinning factors exceed that of whole crust, showing an inverse discrepancy and (2) upper crustal faulting was sufficient to explain the whole crustal thinning in a narrow area of the basin center, indicating no extension discrepancy. The inverse discrepancy in the western basin results from relatively weak ductile shearing in the lower crust, while in the eastern basin, it is caused by intense sequential detachment faulting in the upper crust. Moreover, lower crust exhumation may trigger magma underplating, which further decreases whole crustal thinning factors. Overall, the hyper‐thinning process of the continental crust beneath the Baiyun Rift is dominated by sequential detachment faulting and is characterized by upper crustal thinning factors equaling or significantly exceeding whole crustal thinning factors.
Evidence of Sub‐MeV EMIC‐Driven Trapped Electron Flux Dropouts From GPS Observations
Authors: Hendry A. T. , Rodger C. J. , Clilverd M. A. , Morley S. K.
Published: April 2021

For many years, it was believed that resonant interactions between electromagnetic ion cyclotron (EMIC) waves and radiation belt electrons were restricted to electron energies >1–2 MeV. In recent years, however, a growing body of experimental evidence has shown that EMIC waves can cause the scattering loss of electrons down to sub‐MeV energies. Using measurements of trapped electron flux from the Global Positioning System satellite constellation, we investigate the ability of EMIC waves to cause significant depletions of radiation belt electron populations between 4 ≤ L* ≤ 5. For the first time, we present statistical evidence demonstrating global decreases in sub‐MeV trapped electron flux in response to EMIC wave activity. Although we find that electron losses extend down to sub‐MeV energies, we also show strong statistical support for the ability of EMIC waves to preferentially cause substantial depletions of ultra‐relativistic electrons in the radiation belts.
Revealing unconventional host–guest complexation at nanostructured interface by surface-enhanced Raman spectroscopy
Authors: Chen Gan-Yu , Sun Yi-Bin , Shi Pei-Chen , Liu Tao , Li Zhi-Hao , Luo Si-Heng , Wang Xin-Chang , Cao Xiao-Yu , Ren Bin , Liu Guo-Kun , Yang Liu-Lin , Tian Zhong-Qun
Published: April 2021

Interfacial host–guest complexation offers a versatile way to functionalize nanomaterials. However, the complicated interfacial environment and trace amounts of components present at the interface make the study of interfacial complexation very difficult. Herein, taking the advantages of near-single-molecule level sensitivity and molecular fingerprint of surface-enhanced Raman spectroscopy (SERS), we reveal that a cooperative effect between cucurbit[7]uril (CB[7]) and methyl viologen (MV2+2I−) in aggregating Au NPs originates from the cooperative adsorption of halide counter anions I−, MV2+, and CB[7] on Au NPs surface. Moreover, similar SERS peak shifts in the control experiments using CB[n]s but with smaller cavity sizes suggested the occurrence of the same guest complexations among CB[5], CB[6], and CB[7] with MV2+. Hence, an unconventional exclusive complexation model is proposed between CB[7] and MV2+ on the surface of Au NPs, distinct from the well-known 1:1 inclusion complexation model in aqueous solutions. In summary, new insights into the fundamental understanding of host–guest interactions at nanostructured interfaces were obtained by SERS, which might be useful for applications related to host–guest chemistry in engineered nanomaterials.
Quasi-two-dimensional perovskite light emitting diodes for bright future
Authors: Lee Jin-Wook , Park Nam-Gyu
Published: April 2021

The fundamentals, promise and challenges of metal halide quasi-two-dimensional (quasi-2D) perovskites for a next generation emitter in light emitting diode devices are systematically reviewed.
Correction to: Adaptive immune responses to SARS-CoV-2 infection in severe versus mild individuals
Authors: Zhang Fan , Gan Rui , Zhen Ziqi , Hu Xiaoli , Li Xiang , Zhou Fengxia , Liu Ying , Chen Chuangeng , Xie Shuangyu , Zhang Bailing , Wu Xiaoke , Huang Zhiwei
Published: April 2021

A Correction to this paper has been published: https://doi.org/10.1038/s41392-021-00540-4
Up-regulated circBACH2 contributes to cell proliferation, invasion, and migration of triple-negative breast cancer
Authors: Wang Xinxing , Xue Bingjian , Zhang Yujie , Guo Guangcheng , Duan Xin , Dou Dongwei
Published: April 2021

An increasing amount of evidence has proven the vital role of circular RNAs (circRNAs) in cancer progression. However, there remains a dearth of knowledge on the function of circRNAs in triple-negative breast cancer (TNBC). Utilizing a circRNA microarray dataset, four circRNAs were identified to be abnormally expressed in TNBC. Among them, circBACH2 was most significantly elevated in TNBC cancerous tissues and its high expression was positively correlated to the malignant progression of TNBC patients. In normal human mammary gland cell line, the overexpression of circBACH2 facilitated epithelial to mesenchymal transition and cell proliferation. In TNBC cell lines, circBACH2 knockdown suppressed the malignant progression of TNBC cells. Mechanistically, circBACH2 sponged miR-186-5p and miR-548c-3p, thus releasing the C-X-C chemokine receptor type 4 (CXCR4) expression. The interference of miR-186-5p/miR-548c-3p efficiently promoted the cell proliferation, migration, and invasion suppressed by circBACH2 knockdown in the TNBC cell lines. Finally, circBACH2 knockdown repressed the growth and lung metastasis of TNBC xenografts in nude mice. In summary, circBACH2 functions as an oncogenic circRNA in TNBC through a novel miR-186-5p/miR-548c-3p/CXCR4 axis.
Energy harvesting optical modulators with sub-attojoule per bit electrical energy consumption
Authors: de Cea M. , Atabaki A. H. , Ram R. J.
Published: April 2021

The light input to a semiconductor optical modulator can constitute an electrical energy supply through the photovoltaic effect, which is unexploited in conventional modulators. In this work, we leverage this effect to demonstrate a silicon modulator with sub-aJ/bit electrical energy consumption at sub-GHz speeds, relevant for massively parallel input/output systems such as neural interfaces. We use the parasitic photovoltaic current to self-charge the modulator and a single transistor to modulate the stored charge. This way, the electrical driver only needs to charge the nano-scale gate of the transistor, with attojoule-scale energy dissipation. We implement this ‘photovoltaic modulator’ in a monolithic CMOS platform. This work demonstrates how close integration and co-design of electronics and photonics offers a path to optical switching with as few as 500 injected electrons and electrical energy consumption as low as 20 zJ/bit, achieved only by recovering the absorbed optical energy that is wasted in conventional modulation.
Cytoplasmic condensation induced by membrane damage is associated with antibiotic lethality
Authors: Wong Felix , Stokes Jonathan M. , Cervantes Bernardo , Penkov Sider , Friedrichs Jens , Renner Lars D. , Collins James J.
Published: April 2021

Bactericidal antibiotics kill bacteria by perturbing various cellular targets and processes. Disruption of the primary antibiotic-binding partner induces a cascade of molecular events, leading to overproduction of reactive metabolic by-products. It remains unclear, however, how these molecular events contribute to bacterial cell death. Here, we take a single-cell physical biology approach to probe antibiotic function. We show that aminoglycosides and fluoroquinolones induce cytoplasmic condensation through membrane damage and subsequent outflow of cytoplasmic contents as part of their lethality. A quantitative model of membrane damage and cytoplasmic leakage indicates that a small number of nanometer-scale membrane defects in a single bacterium can give rise to the cellular-scale phenotype of cytoplasmic condensation. Furthermore, cytoplasmic condensation is associated with the accumulation of reactive metabolic by-products and lipid peroxidation, and pretreatment of cells with the antioxidant glutathione attenuates cytoplasmic condensation and cell death. Our work expands our understanding of the downstream molecular events that are associated with antibiotic lethality, revealing cytoplasmic condensation as a phenotypic feature of antibiotic-induced bacterial cell death.
A time-domain phase diagram of metastable states in a charge ordered quantum material
Authors: Ravnik Jan , Diego Michele , Gerasimenko Yaroslav , Vaskivskyi Yevhenii , Vaskivskyi Igor , Mertelj Tomaz , Vodeb Jaka , Mihailovic Dragan
Published: April 2021

Metastable self-organized electronic states in quantum materials are of fundamental importance, displaying emergent dynamical properties that may be used in new generations of sensors and memory devices. Such states are typically formed through phase transitions under non-equilibrium conditions and the final state is reached through processes that span a large range of timescales. Conventionally, phase diagrams of materials are thought of as static, without temporal evolution. However, many functional properties of materials arise as a result of complex temporal changes in the material occurring on different timescales. Hitherto, such properties were not considered within the context of a temporally-evolving phase diagram, even though, under non-equilibrium conditions, different phases typically evolve on different timescales. Here, by using time-resolved optical techniques and femtosecond-pulse-excited scanning tunneling microscopy (STM), we track the evolution of the metastable states in a material that has been of wide recent interest, the quasi-two-dimensional dichalcogenide 1T-TaS2. We map out its temporal phase diagram using the photon density and temperature as control parameters on timescales ranging from 10−12 to 103 s. The introduction of a time-domain axis in the phase diagram enables us to follow the evolution of metastable emergent states created by different phase transition mechanisms on different timescales, thus enabling comparison with theoretical predictions of the phase diagram, and opening the way to understanding of the complex ordering processes in metastable materials.
Molecular landscape of etioplast inner membranes in higher plants
Authors: Floris Davide , Kühlbrandt Werner
Published: April 2021

Etioplasts are photosynthetically inactive plastids that accumulate when light levels are too low for chloroplast maturation. The etioplast inner membrane consists of a paracrystalline tubular lattice and peripheral, disk-shaped membranes, respectively known as the prolamellar body and prothylakoids. These distinct membrane regions are connected into one continuous compartment. To date, no structures of protein complexes in or at etioplast membranes have been reported. Here, we used electron cryo-tomography to explore the molecular membrane landscape of pea and maize etioplasts. Our tomographic reconstructions show that ATP synthase monomers are enriched in the prothylakoids, and plastid ribosomes in the tubular lattice. The entire tubular lattice is covered by regular helical arrays of a membrane-associated protein, which we identified as the 37-kDa enzyme, light-dependent protochlorophyllide oxidoreductase (LPOR). LPOR is the most abundant protein in the etioplast, where it is responsible for chlorophyll biosynthesis, photoprotection and defining the membrane geometry of the prolamellar body. Based on the 9-Å-resolution volume of the subtomogram average, we propose a structural model of membrane-associated LPOR.
Author Correction: Predicting dissolution and transformation of inhaled nanoparticles in the lung using abiotic flow cells: The case of barium sulphate
Authors: Keller Johannes G. , Graham Uschi M. , Koltermann-Jülly Johanna , Gelein Robert , Ma-Hock Lan , Landsiedel Robert , Wiemann Martin , Oberdörster Günter , Elder Alison , Wohlleben Wendel
Published: April 2021

An amendment to this paper has been published and can be accessed via a link at the top of the paper.