bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationships Between the Typhoon‐Induced Wind and Waves in the Northern South China Sea
Authors: Niu Qianru , Feng Yanqing
Published: March 2021

Wind‐wave interactions have been broadly investigated for their great implications on air‐sea momentum transfer, whereas our knowledge on those forced by typhoons (hurricanes) is still limited. Accordingly, relationships between wind and wave characteristics were analyzed using observations on the northern South China Sea during four typhoons. An empirical wind‐wave model was proposed for typhoon‐induced wind seas which exhibits satisfactory skills in predicting significant wave heights (). Meanwhile, typhoon‐forced wind‐wave relation was investigated using the wave growth function. By delineating the relationship between the dimensionless and peak wave period scaled with 10 m and friction wind velocities, simplified functions for the growing and steady wind seas were proposed, respectively. However, great misalignment could occur owing to the contamination of swells resulting from the typhoon's slow translation speed, as well as the extremely short or long radial distance from typhoon centers, indicating the necessity of considering typhoon structures in screening swell influences.
Scrambling and Reorientation of Classical Atmospheric Boundary Layer Turbulence in Hurricane Winds
Authors: Momen Mostafa , Parlange Marc B. , Giometto Marco G.
Published: March 2021

The societal, economic, and ecosystem consequences of hurricanes are projected to increase with ocean warming. Although wind gusts can be highly destructive in these extreme events, current knowledge on hurricane turbulence structures is limited due to insufficient measurement sampling data and the low resolution (1–5 km) of weather models. To bridge this knowledge gap, we propose and validate a numerical approach based on a novel theoretical framework that enables us to simulate hurricane boundary layer (BL) at ≈25 m resolution. Our high‐resolution simulations revealed an intermediate layer in the hurricane BL in which the streamwise‐elongated coherent turbulence structures that typically populate the BL flows are broken into smaller eddies. The distinctive structure of turbulence in cyclonic winds also alters internal BL dynamics during hurricane landfalls by reorienting the roll vortices. We demonstrate that the centrifugal forces in hurricanes cause scrambling and reorientation of the elongated conventional atmospheric BL streaks.
Satellite Remote Sensing of Herring (Clupea pallasii) Spawning Events: A Case Study in the Strait of Georgia
Authors: Qi Lin , Zhang Shuai , Manos Alexander J. , Hay Douglas E. , McCarter Bruce , Wang Menghua , Mikelsons Karlis , Hu Chuanmin
Published: March 2021

In this proof‐of‐concept study, we show how satellite remote sensing can be used to detect and monitor Pacific herring spawning events in the Strait of Georgia (SoG), British Columbia, Canada. Multi‐sensor medium‐resolution (∼300 m) and high‐resolution (3–30 m) images reveal bright waters in the SoG due to high concentrations of herring milt from multiple spawning events. The milt‐infused waters lead to enhanced reflectance with unique spectral characteristic that can be distinguished from other optically active constituents such as suspended sediments, coccolithophores, “whiting” particles, and shallow bottoms. While the medium‐resolution images may be used to search for cloud‐free and potential spawning sites, high‐resolution images show more details in milt distributions. Given the increased availability of high‐resolution satellite imagery at the global scale, this demonstration may promote more applications of satellite remote sensing in fisheries and ocean ecology research.
Record‐Low Cloud Temperatures Associated With a Tropical Deep Convective Event
Authors: Proud Simon Richard , Bachmeier Scott
Published: March 2021

Earth‐orbiting satellites have long been used to examine meteorological processes. In the context of severe weather, brightness temperatures (BTs) at infrared wavelengths allow the determination of convective cloud properties. The anvils of cumulonimbus clouds, for example, typically produce BTs close to the tropopause temperature. Particularly severe storms generate overshoots that penetrate the stratosphere and are cooler than the anvil. In this study, we describe clustered storm overshoots in the tropical West Pacific on December 29, 2018 that resulted in the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard NOAA‐20 measuring a temperature of 161.96K (−111.2°C), which is, to our knowledge, the coldest on record. We describe the local meteorological conditions, examine the VIIRS overpass that produced the cold temperature, compare VIIRS with other sensors that observed the region and, finally, analyze the historical context provided by two other satellite instruments to show that such cold temperatures may be becoming more common.
Climatology of Near‐Surface Daily Peak Wind Gusts Across Scandinavia: Observations and Model Simulations
Authors: Minola Lorenzo , Azorin‐Molina Cesar , Guijarro Jose A. , Zhang Gangfeng , Son Seok‐Woo , Chen Deliang
Published: March 2021

An observed daily peak wind gusts (DPWG) dataset over Scandinavia, consisting of time series from 127 meteorological stations across Finland, Norway and Sweden, has been created. This dataset provides high‐quality and homogenized near‐surface DPWG series for Scandinavia, spanning the longest available time period (1996–2016). The aim of this study is to evaluate the ability of two regional climate models (RCMs) in simulating DPWG winds. According to the observed DPWG climatology, meteorological stations are classified into three regions for which wind conditions are influenced by similar physical processes: coast, inland and mountain. Smaller‐scale DPWG features of the three regions are only captured when coarser general circulation models or reanalyses are downscaled by a RCM. Dynamic downscaling is thus needed to achieve more realistic simulations of DPWG when compared to their driving models. The performances of the RCMs are found to be more dependent on model dynamics and physics (such as gust parametrization) than on the boundary conditions provided by the driving models. We also found that the RCMs cannot accurately simulate observed DPWG in inland and mountainous areas, suggesting the need for higher horizontal resolution and/or better representation of relevant boundary‐layer processes.
Contrasting Observed Atmospheric Responses to Tropical Sea Surface Temperature Warming Patterns
Authors: Mackie Anna , Brindley Helen E. , Palmer Paul I.
Published: March 2021

Equilibrium climate sensitivity (ECS) is a theoretical concept which describes the change in global mean surface temperature that results from a sustained doubling of atmospheric CO2. Current ECS estimates range from ∼1.8 to 5.6 K, reflecting uncertainties in climate feedbacks. The sensitivity of the lower (1,000–700 hPa) and upper (500–200 hPa) troposphere to changes in spatial patterns of tropical sea surface temperature (SST) have been proposed by recent model studies as key feedbacks controlling climate sensitivity. We examine empirical evidence for these proposed mechanisms using 14 years of satellite data. We examine the response of temperature and humidity profiles, clouds, and top‐of‐the‐atmosphere radiation to relative warming in tropical ocean regions when there is either strong convection or subsidence. We find warmer SSTs in regions of strong subsidence are coincident with a decrease in lower tropospheric stability (−0.9 ± 0.4 KK−1) and low cloud cover (∼−6% K−1). This leads to a warming associated with the weakening in the shortwave cooling effect of clouds (4.2 ± 1.9 Wm−2K−1), broadly consistent with model calculations. In contrast, warmer SSTs in regions of strong convection are coincident with an increase in upper tropospheric humidity (3.2 ± 1.5% K−1). In this scenario, the dominant effect is the enhancement of the warming longwave cloud radiative effect (3.8 ± 3.0 Wm−2K−1) from an increase in high cloud cover (∼7% K−1), though changes in the net (longwave and shortwave) effect are not statistically significant (p < 0.003). Our observational evidence supports the existence of mechanisms linking contrasting atmospheric responses to patterns in SST, mechanisms which have been linked to climate sensitivity.
Increased Marine Productivity in the Southern Humboldt Current System During MIS 2–4 and 10–11
Authors: Tapia Raúl , Ho Sze Ling , Núñez‐Ricardo Samuel , Marchant Margarita , Lamy Frank , Hebbeln Dierk
Published: March 2021

The Humboldt Current System (HCS) is characterized by high marine primary productivity, the dynamics of which are closely linked to climate variability. However, its changes beyond the last glacial cycle are virtually unknown due to a dearth of long sediment records. Here, we present a 500 ka multi‐proxy marine productivity reconstruction from the southernmost part of the HCS (∼43 S). At these latitudes, marine productivity changes have been typically attributed to glacial‐interglacial changes in the South Pacific Subtropical High (SPSH) and Southern Westerly Winds (SWWs). Surprisingly, our productivity reconstruction based on biomarkers and benthic foraminifera does not show recurrent glacial‐interglacial variability. Instead, large increases in organic matter flux occurred during MIS 2–4 and MIS 10–11. Micronutrients in aeolian dust and Southern Ocean‐sourced macronutrients seem to be unlikely drivers, as both would have led to recurrent glacial‐interglacial variability as observed elsewhere. Another source of micronutrients is via continental runoff, the amount of which is controlled by Patagonian Ice Sheet variability and/or precipitation. We interpret our productivity records as reflecting changes in the amount of nutrients supplied by continental runoff, which are driven by precipitation variations linked to the configuration of the SPSH‐SWWs in response to orbital forcing in the eccentricity band. During eccentricity minima, the position of SPSH changes minimally from precession minima to maxima. This SPSH‐SWWs configuration probably results in a prolonged period of high precipitation, which in turn increases the continental runoff and the supply of micronutrients to the sea.
Atmospheric Turbulence May Promote Cloud Droplet Formation
Authors: Rehnberg Morgan
Published: March 2021

Turbulence causes local variations in relative humidity, which can push particles past a critical saturation threshold for droplet nucleation.
Vicu�a Poop Nourishes “Dung Gardens” High in the Andes
Authors: Kornei Katherine
Published: March 2021

The excrement delivers nutrients like phosphorus and nitrogen, kick-starting islands of vegetation at the edge of the cryosphere.
Downregulation of ceramide synthase 1 promotes oral cancer through endoplasmic reticulum stress
Authors: Chen Wen , Wu Chenzhou , Chen Yafei , Guo Yuhao , Qiu Ling , Liu Zhe , Sun Haibin , Chen Siyu , An Zijian , Zhang Zhuoyuan , Li Yi , Li Longjiang
Published: March 2021

C18 ceramide plays an important role in the occurrence and development of oral squamous cell carcinoma. However, the function of ceramide synthase 1, a key enzyme in C18 ceramide synthesis, in oral squamous cell carcinoma is still unclear. The aim of our study was to investigate the relationship between ceramide synthase 1 and oral cancer. In this study, we found that the expression of ceramide synthase 1 was downregulated in oral cancer tissues and cell lines. In a mouse oral squamous cell carcinoma model induced by 4-nitroquinolin-1-oxide, ceramide synthase 1 knockout was associated with the severity of oral malignant transformation. Immunohistochemical studies showed significant upregulation of PCNA, MMP2, MMP9, and BCL2 expression and downregulation of BAX expression in the pathological hyperplastic area. In addition, ceramide synthase 1 knockdown promoted cell proliferation, migration, and invasion in vitro. Overexpression of CERS1 obtained the opposite effect. Ceramide synthase 1 knockdown caused endoplasmic reticulum stress and induced the VEGFA upregulation. Activating transcription factor 4 is responsible for ceramide synthase 1 knockdown caused VEGFA transcriptional upregulation. In addition, mild endoplasmic reticulum stress caused by ceramide synthase 1 knockdown could induce cisplatin resistance. Taken together, our study suggests that ceramide synthase 1 is downregulated in oral cancer and promotes the aggressiveness of oral squamous cell carcinoma and chemotherapeutic drug resistance.
Umbilical cord blood-derived microglia-like cells to model COVID-19 exposure
Authors: Sheridan Steven D. , Thanos Jessica M. , De Guzman Rose M. , McCrea Liam T. , Horng Joy E. , Fu Ting , Sellgren Carl M. , Perlis Roy H. , Edlow Andrea G.
Published: March 2021

Microglia, the resident brain immune cells, play a critical role in normal brain development, and are impacted by the intrauterine environment, including maternal immune activation and inflammatory exposures. The COVID-19 pandemic presents a potential developmental immune challenge to the fetal brain, in the setting of maternal SARS-CoV-2 infection with its attendant potential for cytokine production and, in severe cases, cytokine storming. There is currently no biomarker or model for in utero microglial priming and function that might aid in identifying the neonates and children most vulnerable to neurodevelopmental morbidity, as microglia remain inaccessible in fetal life and after birth. This study aimed to generate patient-derived microglial-like cell models unique to each neonate from reprogrammed umbilical cord blood mononuclear cells, adapting and extending a novel methodology previously validated for adult peripheral blood mononuclear cells. We demonstrate that umbilical cord blood mononuclear cells can be used to create microglial-like cell models morphologically and functionally similar to microglia observed in vivo. We illustrate the application of this approach by generating microglia from cells exposed and unexposed to maternal SARS-CoV-2 infection. Our ability to create personalized neonatal models of fetal brain immune programming enables non-invasive insights into fetal brain development and potential childhood neurodevelopmental vulnerabilities for a range of maternal exposures, including COVID-19.
Kinesin family member 18B regulates the proliferation and invasion of human prostate cancer cells
Authors: Wu Yu-Peng , Ke Zhi-Bin , Zheng Wen-Cai , Chen Ye-Hui , Zhu Jun-Ming , Lin Fei , Li Xiao-Dong , Chen Shao-Hao , Cai Hai , Zheng Qing-Shui , Wei Yong , Xue Xue-Yi , Xu Ning
Published: March 2021

Expression of kinesin family member 18B (KIF18B), an ATPase with key roles in cell division, is deregulated in many cancers, but its involvement in prostate cancer (PCa) is unclear. Here, we investigated the expression and function of KIF18B in human PCa specimens and cell lines using bioinformatics analyses, immunohistochemical and immunofluorescence microscopy, and RT-qPCR and western blot analyses. KIF18B was overexpressed in PCa specimens compared with paracancerous tissues and was associated with poorer disease-free survival. In vitro, KIF18B knockdown in PCa cell lines promoted cell proliferation, migration, and invasion, and inhibited cell apoptosis, while KIF18B overexpression had the opposite effects. In a mouse xenograft model, KIF18B overexpression accelerated and promoted the growth of PCa tumors. Bioinformatics analysis of control and KIF18B-overexpressing PCa cells showed that genes involved in the PI3K–AKT–mTOR signaling pathway were significantly enriched among the differentially expressed genes. Consistent with this observation, we found that KIF18B overexpression activates the PI3K–AKT–mTOR signaling pathway in PCa cells both in vitro and in vivo. Collectively, our results suggest that KIF18B plays a crucial role in PCa via activation of the PI3K–AKT–mTOR signaling pathway, and raise the possibility that KIF18B could have utility as a novel biomarker for PCa.
Local and global trace plutonium contributions in fast breeder legacy soils
Authors: Tighe Chris , Castrillejo Maxi , Christl Marcus , Degueldre Claude , Andrew Jeremy , Semple Kirk T. , Joyce Malcolm J.
Published: March 2021

Trace-level plutonium in the environment often comprises local and global contributions, and is usually anthropogenic in origin. Here, we report estimates of local and global contributions to trace-level plutonium in soil from a former, fast-breeder reactor site. The measured 240Pu/239Pu ratio is anomalously low, as per the reduced 240Pu yield expected in plutonium bred with fast neutrons. Anomalies in plutonium concentration and isotopic ratio suggest forensic insight into specific activities on site, such as clean-up or structural change. Local and global 239Pu contributions on-site are estimated at (34 ± 1)% and (66 ± 3)%, respectively, with mass concentrations of (183 ± 6) fg g−1 and (362 ± 13) fg g−1. The latter is consistent with levels at undisturbed and distant sites, (384 ± 44) fg g−1, where no local contribution is expected. The 240Pu/239Pu ratio for site-derived material is estimated at 0.05 ± 0.04. Our study demonstrates the multi-faceted potential of trace plutonium assay to inform clean-up strategies of fast breeder legacies.
Nonlinear delay differential equations and their application to modeling biological network motifs
Authors: Glass David S. , Jin Xiaofan , Riedel-Kruse Ingmar H.
Published: March 2021

Biological regulatory systems, such as cell signaling networks, nervous systems and ecological webs, consist of complex dynamical interactions among many components. Network motif models focus on small sub-networks to provide quantitative insight into overall behavior. However, such models often overlook time delays either inherent to biological processes or associated with multi-step interactions. Here we systematically examine explicit-delay versions of the most common network motifs via delay differential equation (DDE) models, both analytically and numerically. We find many broadly applicable results, including parameter reduction versus canonical ordinary differential equation (ODE) models, analytical relations for converting between ODE and DDE models, criteria for when delays may be ignored, a complete phase space for autoregulation, universal behaviors of feedforward loops, a unified Hill-function logic framework, and conditions for oscillations and chaos. We conclude that explicit-delay modeling simplifies the phenomenology of many biological networks and may aid in discovering new functional motifs.
Amagmatic hydrothermal systems on Mars from radiogenic heat
Authors: Ojha Lujendra , Karunatillake Suniti , Karimi Saman , Buffo Jacob
Published: March 2021

Long-lived hydrothermal systems are prime targets for astrobiological exploration on Mars. Unlike magmatic or impact settings, radiogenic hydrothermal systems can survive for >100 million years because of the Ga half-lives of key radioactive elements (e.g., U, Th, and K), but remain unknown on Mars. Here, we use geochemistry, gravity, topography data, and numerical models to find potential radiogenic hydrothermal systems on Mars. We show that the Eridania region, which once contained a vast inland sea, possibly exceeding the combined volume of all other Martian surface water, could have readily hosted a radiogenic hydrothermal system. Thus, radiogenic hydrothermalism in Eridania could have sustained clement conditions for life far longer than most other habitable sites on Mars. Water radiolysis by radiogenic heat could have produced H2, a key electron donor for microbial life. Furthermore, hydrothermal circulation may help explain the region’s high crustal magnetic field and gravity anomaly.
Regulating Fe-spin state by atomically dispersed Mn-N in Fe-N-C catalysts with high oxygen reduction activity
Authors: Yang Gege , Zhu Jiawei , Yuan Pengfei , Hu Yongfeng , Qu Gan , Lu Bang-An , Xue Xiaoyi , Yin Hengbo , Cheng Wenzheng , Cheng Junqi , Xu Wenjing , Li Jin , Hu Jinsong , Mu Shichun , Zhang Jia-Nan
Published: March 2021

As low-cost electrocatalysts for oxygen reduction reaction applied to fuel cells and metal-air batteries, atomic-dispersed transition metal-nitrogen-carbon materials are emerging, but the genuine mechanism thereof is still arguable. Herein, by rational design and synthesis of dual-metal atomically dispersed Fe,Mn/N-C catalyst as model object, we unravel that the O2 reduction preferentially takes place on FeIII in the FeN4 /C system with intermediate spin state which possesses one eg electron (t2g4eg1) readily penetrating the antibonding π-orbital of oxygen. Both magnetic measurements and theoretical calculation reveal that the adjacent atomically dispersed Mn-N moieties can effectively activate the FeIII sites by both spin-state transition and electronic modulation, rendering the excellent ORR performances of Fe,Mn/N-C in both alkaline and acidic media (halfwave positionals are 0.928 V in 0.1 M KOH, and 0.804 V in 0.1 M HClO4), and good durability, which outperforms and has almost the same activity of commercial Pt/C, respectively. In addition, it presents a superior power density of 160.8 mW cm−2 and long-term durability in reversible zinc–air batteries. The work brings new insight into the oxygen reduction reaction process on the metal-nitrogen-carbon active sites, undoubtedly leading the exploration towards high effective low-cost non-precious catalysts.
Infrared photoconduction at the diffusion length limit in HgTe nanocrystal arrays
Authors: Chu Audrey , Gréboval Charlie , Prado Yoann , Majjad Hicham , Delerue Christophe , Dayen Jean-Francois , Vincent Grégory , Lhuillier Emmanuel
Published: March 2021

Narrow band gap nanocrystals offer an interesting platform for alternative design of low-cost infrared sensors. It has been demonstrated that transport in HgTe nanocrystal arrays occurs between strongly-coupled islands of nanocrystals in which charges are partly delocalized. This, combined with the scaling of the noise with the active volume of the film, make case for device size reduction. Here, with two steps of optical lithography we design a nanotrench which effective channel length corresponds to 5–10 nanocrystals, matching the carrier diffusion length. We demonstrate responsivity as high as 1 kA W−1, which is 105 times higher than for conventional µm-scale channel length. In this work the associated specific detectivity exceeds 1012 Jones for 2.5 µm peak detection under 1 V at 200 K and 1 kHz, while the time response is as short as 20 µs, making this performance the highest reported for HgTe NC-based extended short-wave infrared detection.
Flow-sensory contact electrification of graphene
Authors: Zhang Xiaoyu , Chia Eric , Fan Xiao , Ping Jinglei
Published: March 2021

All-electronic interrogation of biofluid flow velocity by electrical nanosensors incorporated in ultra-low-power or self-sustained systems offers the promise of enabling multifarious emerging research and applications. However, existing nano-based electrical flow sensing technologies remain lacking in precision and stability and are typically only applicable to simple aqueous solutions or liquid/gas dual-phase mixtures, making them unsuitable for monitoring low-flow (~micrometer/second) yet important characteristics of continuous biofluids (such as hemorheological behaviors in microcirculation). Here, we show that monolayer-graphene single microelectrodes harvesting charge from continuous aqueous flow provide an effective flow sensing strategy that delivers key performance metrics orders of magnitude higher than other electrical approaches. In particular, over six-months stability and sub-micrometer/second resolution in real-time quantification of whole-blood flows with multiscale amplitude-temporal characteristics are obtained in a microfluidic chip.
Multiplexed histology analyses for the phenotypic and spatial characterization of human innate lymphoid cells
Authors: Pascual-Reguant Anna , Köhler Ralf , Mothes Ronja , Bauherr Sandy , Hernández Daniela C. , Uecker Ralf , Holzwarth Karolin , Kotsch Katja , Seidl Maximilian , Philipsen Lars , Müller Werner , Romagnani Chiara , Niesner Raluca , Hauser Anja E.
Published: March 2021

Innate lymphoid cells (ILCs) emerge in the last few years as important regulators of immune responses and biological processes. Although ILCs are mainly known as tissue-resident cells, their precise localization and interactions with the microenvironment are still unclear. Here we combine a multiplexed immunofluorescence technique and a customized computational, open-source analysis pipeline to unambiguously identify CD127+ ILCs in situ and characterize these cells and their microenvironments. Moreover, we reveal the transcription factor IRF4 as a marker for tonsillar ILC3, and identify conserved stromal landmarks characteristic for ILC localization. We also show that CD127+ ILCs share tissue niches with plasma cells in the tonsil. Our works thus provide a platform for multiparametric histological analysis of ILCs to improve our understanding of ILC biology.
Nutrient restriction synergizes with retinoic acid to induce mammalian meiotic initiation in vitro
Authors: Zhang Xiaoyu , Gunewardena Sumedha , Wang Ning
Published: March 2021

The molecular machinery and chromosome structures carrying out meiosis are frequently conserved from yeast to mammals. However, signals initiating meiosis appear divergent: while nutrient restriction induces meiosis in the yeast system, retinoic acid (RA) and its target Stra8 have been shown to be necessary but not sufficient to induce meiotic initiation in mammalian germ cells. Here, we use primary culture of mouse undifferentiated spermatogonia without the support of gonadal somatic cells to show that nutrient restriction in combination with RA is sufficient to induce Stra8- and Spo11-dependent meiotic gene and chromosome programs that recapitulate the transcriptomic and cytologic features of in vivo meiosis. We demonstrate that neither nutrient restriction nor RA alone exerts these effects. Moreover, we identify a distinctive network of 11 nutrient restriction-upregulated transcription factor genes, which are associated with early meiosis in vivo and whose expression does not require RA. Our study proposes a conserved model, in which nutrient restriction induces meiotic initiation by upregulating key transcription factor genes for the meiotic gene program and provides an in vitro platform for meiotic induction that could facilitate research and haploid gamete production.
Momentum space toroidal moment in a photonic metamaterial
Authors: Yang Biao , Bi Yangang , Zhang Rui-Xing , Zhang Ruo-Yang , You Oubo , Zhu Zhihong , Feng Jing , Sun Hongbo , Chan C. T. , Liu Chao-Xing , Zhang Shuang
Published: March 2021

Berry curvature, the counterpart of the magnetic field in the momentum space, plays a vital role in the transport of electrons in condensed matter physics. It also lays the foundation for the emerging field of topological physics. In the three-dimensional systems, much attention has been paid to Weyl points, which serve as sources and drains of Berry curvature. Here, we demonstrate a toroidal moment of Berry curvature with flux approaching toπin judiciously engineered metamaterials. The Berry curvature exhibits a vortex-like configuration without any source and drain in the momentum space. Experimentally, the presence of Berry curvature toroid is confirmed by the observation of conical-frustum shaped domain-wall states at the interfaces formed by two metamaterials with opposite toroidal moments.
Prosocial and antisocial choices in a monogamous cichlid with biparental care
Authors: Satoh Shun , Bshary Redouan , Shibasaki Momoko , Inaba Seishiro , Sogawa Shumpei , Hotta Takashi , Awata Satoshi , Kohda Masanori
Published: March 2021

Human society is cooperative and characterized by spontaneous prosociality. Comparative studies on endotherm vertebrates suggest that social interdependence causes the evolution of proactive prosociality. To test the generality of this hypothesis, we modify a prosocial choice task for application to the convict cichlid,Amatitlania nigrofasciata, a monogamous fish with biparental care and a strong pair bond. We also affirm that male subjects learn to favor prosocial choices when their mates are the recipients in a neighboring tank. When the neighboring tank is empty, males choose randomly. Furthermore, in the absence of their mates, males behave prosocially toward a stranger female. However, if the mate of the subjects is also visible in the third tank, or if a male is a potential recipient, then subjects make antisocial choices. To conclude, fish may show both spontaneous prosocial and antisocial behaviors according to their social relationships with conspecifics and the overall social context.
R-loop resolution promotes co-transcriptional chromatin silencing
Authors: Xu Congyao , Wu Zhe , Duan Hong-Chao , Fang Xiaofeng , Jia Guifang , Dean Caroline
Published: March 2021

RNA-mediated chromatin silencing is central to genome regulation in many organisms. However, how nascent non-coding transcripts regulate chromatin is poorly understood. Here, through analysis of Arabidopsis FLC, we show that resolution of a nascent-transcript-induced R-loop promotes chromatin silencing. Stabilization of an antisense-induced R-loop at the 3′ end of FLC enables an RNA binding protein FCA, with its direct partner FY/WDR33 and other 3′-end processing factors, to polyadenylate the nascent antisense transcript. This clears the R-loop and recruits the chromatin modifiers demethylating H3K4me1. FCA immunoprecipitates with components of the m6A writer complex, and m6A modification affects dynamics of FCA nuclear condensates, and promotes FLC chromatin silencing. This mechanism also targets other loci in the Arabidopsis genome, and consistent with this fca and fy are hypersensitive to a DNA damage-inducing drug. These results show how modulation of R-loop stability by co-transcriptional RNA processing can trigger chromatin silencing.
Dysregulation of mitochondria-lysosome contacts by GBA1 dysfunction in dopaminergic neuronal models of Parkinson’s disease
Authors: Kim Soojin , Wong Yvette C. , Gao Fanding , Krainc Dimitri
Published: March 2021

Mitochondria-lysosome contacts are recently identified sites for mediating crosstalk between both organelles, but their role in normal and diseased human neurons remains unknown. In this study, we demonstrate that mitochondria-lysosome contacts can dynamically form in the soma, axons, and dendrites of human neurons, allowing for their bidirectional crosstalk. Parkinson’s disease patient derived neurons harboring mutant GBA1 exhibited prolonged mitochondria-lysosome contacts due to defective modulation of the untethering protein TBC1D15, which mediates Rab7 GTP hydrolysis for contact untethering. This dysregulation was due to decreased GBA1 (β-glucocerebrosidase (GCase)) lysosomal enzyme activity in patient derived neurons, and could be rescued by increasing enzyme activity with a GCase modulator. These defects resulted in disrupted mitochondrial distribution and function, and could be further rescued by TBC1D15 in Parkinson’s patient derived GBA1-linked neurons. Together, our work demonstrates a potential role of mitochondria-lysosome contacts as an upstream regulator of mitochondrial function and dynamics in midbrain dopaminergic neurons in GBA1-linked Parkinson’s disease.
Asymmetric three-component olefin dicarbofunctionalization enabled by photoredox and copper dual catalysis
Authors: Wang Peng-Zi , Gao Yuan , Chen Jun , Huan Xiao-Die , Xiao Wen-Jing , Chen Jia-Rong
Published: March 2021

The intermolecular three-component alkene vicinal dicarbofunctionalization (DCF) reaction allows installation of two different carbon fragments. Despite extensive investigation into its ionic chemistry, the enantioseletive radical-mediated versions of DCF reactions remain largely unexplored. Herein, we report an intermolecular, enantioselective three-component radical vicinal dicarbofunctionalization reaction of olefins enabled by merger of radical addition and cross-coupling using photoredox and copper dual catalysis. Key to the success of this protocol relies on chemoselective addition of acyl and cyanoalkyl radicals, generated in situ from the redox-active oxime esters by a photocatalytic N-centered iminyl radical-triggered C-C bond cleavage event, onto the alkenes to form new carbon radicals. Single electron metalation of such newly formed carbon radicals to TMSCN-derived L1Cu(II)(CN)2 complex leads to asymmetric cross-coupling. This three-component process proceeds under mild conditions, and tolerates a diverse range of functionalities and synthetic handles, leading to valuable optically active β–cyano ketones and alkyldinitriles, respectively, in a highly enantioselective manner (>60 examples, up to 97% ee).
Author Correction: Genome evolution and the emergence of pathogenicity in avian Escherichia coli
Authors: Mageiros Leonardos , Méric Guillaume , Bayliss Sion C. , Pensar Johan , Pascoe Ben , Mourkas Evangelos , Calland Jessica K. , Yahara Koji , Murray Susan , Wilkinson Thomas S. , Williams Lisa K. , Hitchings Matthew D. , Porter Jonathan , Kemmett Kirsty , Feil Edward J. , Jolley Keith A. , Williams Nicola J. , Corander Jukka , Sheppard Samuel K.
Published: March 2021

A Correction to this paper has been published: https://doi.org/10.1038/s41467-021-22238-5
Breast adipocyte size associates with ipsilateral invasive breast cancer risk after ductal carcinoma in situ
Authors: Almekinders Mathilde M. M. , Schaapveld Michael , Thijssen Bram , Visser Lindy L. , Bismeijer Tycho , Sanders Joyce , Isnaldi Edoardo , Hofland Ingrid , Mertz Marjolijn , Wessels Lodewyk F. A. , Broeks Annegien , Hooijberg Erik , Zwart Wilbert , Lips Esther H. ,   Grand Challenge PRECISION Consortium, Desmedt Christine , Wesseling Jelle
Published: March 2021

Although ductal carcinoma in situ (DCIS) is a non-obligate precursor to ipsilateral invasive breast cancer (iIBC), most DCIS lesions remain indolent. Hence, overdiagnosis and overtreatment of DCIS is a major concern. There is an urgent need for prognostic markers that can distinguish harmless from potentially hazardous DCIS. We hypothesised that features of the breast adipose tissue may be associated with risk of subsequent iIBC. We performed a case–control study nested in a population-based DCIS cohort, consisting of 2658 women diagnosed with primary DCIS between 1989 and 2005, uniformly treated with breast conserving surgery (BCS) alone. We assessed breast adipose features with digital pathology (HALO®, Indica Labs) and related these to iIBC risk in 108 women that developed subsequent iIBC (cases) and 168 women who did not (controls) by conditional logistic regression, accounting for clinicopathological and immunohistochemistry variables. Large breast adipocyte size was significantly associated with iIBC risk (odds ratio (OR) 2.75, 95% confidence interval (95% CI) = 1.25–6.05). High cyclooxygenase (COX)-2 protein expression in the DCIS cells was also associated with subsequent iIBC (OR 3.70 (95% CI = 1.59–8.64). DCIS with both high COX-2 expression and large breast adipocytes was associated with a 12-fold higher risk (OR 12.0, 95% CI = 3.10–46.3, P < 0.001) for subsequent iIBC compared with women with smaller adipocyte size and low COX-2 expression. Large breast adipocytes combined with high COX-2 expression in DCIS is associated with a high risk of subsequent iIBC. Besides COX-2, adipocyte size has the potential to improve clinical management in patients diagnosed with primary DCIS.
The obesity paradox in early and advanced HER2 positive breast cancer: pooled analysis of clinical trial data
Authors: Modi Natansh D. , Tan Jin Quan Eugene , Rowland Andrew , Koczwara Bogda , Abuhelwa Ahmad Y. , Kichenadasse Ganessan , McKinnon Ross A. , Wiese Michael D. , Sorich Michael J. , Hopkins Ashley M.
Published: March 2021

While many studies have evaluated the relationship between BMI and breast cancer outcomes, it is unclear whether this relationship is consistent between early breast cancer (BC) and advanced BC. The study included 5099 patients with HER2 positive early BC (EBC) and 3496 with HER2 positive advanced BC (ABC). In the EBC cohort, higher BMI was associated with worse overall survival (OS) (HR [95% CI]: overweight = 1.30 [1.13–1.51]; obese = 1.37 [1.14–1.64], P = < 0.001), and worse disease-free survival (overweight = 1.10 [0.98–1.24]; obese = 1.20 [1.04–1.39], P = 0.061). In contrast, for the ABC cohort, higher BMI was significantly associated with improved OS (overweight = 0.85 [0.76–0.96]; obese = 0.82 [0.72–0.95], P = 0.014), and progression-free survival (overweight = 0.91 [0.83–1.01]; obese = 0.87 [0.77–0.98], P = 0.034). In this large high-quality dataset, higher BMI was independently associated with worse survival in EBC, paradoxically in ABC higher BMI was independently associated with improved survival.
A multiscale polymerization framework towards network structure and fracture of double-network hydrogels
Authors: Zhang Mingzhen , Zhang Dong , Chen Hong , Zhang Yanxian , Liu Yonglan , Ren Baiping , Zheng Jie
Published: March 2021

Double-network (DN) hydrogels, consisting of two contrasting and interpenetrating polymer networks, are considered as perhaps the toughest soft-wet materials. Current knowledge of DN gels from synthesis methods to toughening mechanisms almost exclusively comes from chemically-linked DN hydrogels by experiments. Molecular modeling and simulations of inhomogeneous DN structure in hydrogels have proved to be extremely challenging. Herein, we developed a new multiscale simulation platform to computationally investigate the early fracture of physically-chemically linked agar/polyacrylamide (agar/PAM) DN hydrogels at a long timescale. A “random walk reactive polymerization” (RWRP) was developed to mimic a radical polymerization process, which enables to construct a physically-chemically linked agar/PAM DN hydrogel from monomers, while conventional and steered MD simulations were conducted to examine the structural-dependent energy dissipation and fracture behaviors at the relax and deformation states. Collective simulation results revealed that energy dissipation of agar/PAM hydrogels was attributed to a combination of the pulling out of agar chains from the DNs, the disruption of massive hydrogen bonds between and within DN structures, and the strong association of water molecules with both networks, thus explaining a different mechanical enhancement of agar/PAM hydrogels. This computational work provided atomic details of network structure, dynamics, solvation, and interactions of a hybrid DN hydrogel, and a different structural-dependent energy dissipation mode and fracture behavior of a hybrid DN hydrogel, which help to design tough hydrogels with new network structures and efficient energy dissipation modes. Additionally, the RWRP algorithm can be generally applied to construct the radical polymerization-produced hydrogels, elastomers, and polymers.
Microbial interactions with silicate glasses
Authors: Weaver Jamie L. , DePriest Paula T. , Plymale Andrew E. , Pearce Carolyn I. , Arey Bruce , Koestler Robert J.
Published: March 2021

Glass alteration in the presence of microorganisms has been a topic of research for over 150 years. Researchers from a variety of disciplines, including material science, biology, chemistry, geology, physics, and cultural heritage materials preservation have conducted experiments in this area to try and understand when, how, and why microorganism may interact and subsequently influence the alteration of glass. The breadth and depth of these studies are the topic of this review. This review presents a detailed history and a comprehensive overview of this field of research, while maintaining focus on the terrestrial alteration of anthropogenic silicate glasses. Within this manuscript is a schema for bio-interaction with silicate glasses and an outline of an evidence-based hypothesis on how these interactions may influence glass alteration processes. Topics discussed include microbial colonization of glass, development, and interactions of biofilms with glass surface, abiotic vs. biotic alteration processes, and signatures of bio-alteration. Future research needs and a discussion of practical drivers for this research are summarized.
A low-cost, low-density, and corrosion resistant AlFeMnSi compositionally complex alloy
Authors: O’Brien S. P. , Christudasjustus J. , Esteves L. , Vijayan S. , Jinschek J. R. , Birbilis N. , Gupta R. K.
Published: March 2021

A compositionally complex alloy was designed, consisting of equiatomic concentrations of four low-cost commodity elements (Al, Fe, Mn, and Si). The alloy was characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The corrosion of the AlFeMnSi alloy, as evaluated using potentiodynamic polarization tests and electrochemical impedance spectroscopy in 0.6 M NaCl solution, was comparable with that of stainless steel (SS) 304L. Detailed X-ray photoelectron spectroscopy analysis was carried out, including the determination of high-resolution spectra and surface sputtering. In addition, scanning transmission electron microscopy was also used to study the surface film(s) developed after constant immersion. The AlFeMnSi alloy exhibited a unique form of ‘passivity’ that arises from the development of a silicon-rich surface film from dynamic incongruent dissolution.
Clinical characteristics and factors associated with triple therapy use in newly diagnosed patients with COPD
Authors: Monteagudo Mònica , Barrecheguren Miriam , Solntseva Iryna , Dhalwani Nafeesa , Booth Alison , Nuñez Alexa , Lambrelli Dimitra , Miravitlles Marc
Published: March 2021

There is limited information about the initiation of triple therapy (TT) in patients with chronic obstructive pulmonary disease (COPD) in primary care. This was an observational, population-based study in patients identified from a primary care electronic medical records database in Catalonia from 2011 to 2015 aimed to identify the use of TT in patients with newly diagnosed COPD. A total of 69,668 newly diagnosed patients were identified of whom 11,524 (16.5%) initiated TT, of whom 8626 initiated TT at or immediately after COPD diagnosis. Among them, 72.3% were GOLD A/B, 14.6% were frequent exacerbators, and 7.1% had asthma–COPD overlap (ACO). Variables associated with TT initiation were: male sex, older age, previous exacerbations, ACO, a previous treatment regimen containing an inhaled corticosteroid, previous pneumonia, and history of lung cancer. A significant number of COPD patients in Primary Care initiated TT shortly after or even before an established COPD diagnosis.
Contributions of lipopolysaccharide and the type IVB secretion system to Coxiella burnetii vaccine efficacy and reactogenicity
Authors: Long Carrie M. , Beare Paul A. , Cockrell Diane C. , Fintzi Jonathan , Tesfamariam Mahelat , Shaia Carl I. , Heinzen Robert A.
Published: March 2021

Coxiella burnetiiis the bacterial causative agent of the zoonosis Q fever. The current human Q fever vaccine, Q-VAX®, is a fixed, whole cell vaccine (WCV) licensed solely for use in Australia.C. burnetiiWCV administration is associated with a dermal hypersensitivity reaction in people with pre-existing immunity toC. burnetii, limiting wider use. Consequently, a less reactogenic vaccine is needed. Here, we investigated contributions of theC. burnetiiDot/Icm type IVB secretion system (T4BSS) and lipopolysaccharide (LPS) in protection and reactogenicity of fixed WCVs. A 32.5 kb region containing 23dot/icmgenes was deleted in the virulent Nine Mile phase I (NMI) strain and the resulting mutant was evaluated in guinea pig models ofC. burnetiiinfection, vaccination-challenge, and post-vaccination hypersensitivity. The NMI ∆dot/icmstrain was avirulent, protective as a WCV against a robustC. burnetiichallenge, and displayed potentially altered reactogenicity compared to NMI. Nine Mile phase II (NMII) strains ofC. burnetiithat produce rough LPS, were similarly tested. NMI was significantly more protective than NMII as a WCV; however, both vaccines exhibited similar reactogenicity. Collectively, our results indicate that, like phase I LPS, the T4BSS is required for full virulence byC. burnetii. Conversely, unlike phase I LPS, the T4BSS is not required for vaccine-induced protection. LPS length does not appear to contribute to reactogenicity while the T4BSS may contribute to this response. NMI ∆dot/icmrepresents an avirulent phase I strain with full vaccine efficacy, illustrating the potential of genetically modifiedC. burnetiias improved WCVs.
Human endogenous retrovirus-enveloped baculoviral DNA vaccines against MERS-CoV and SARS-CoV2
Authors: Cho Hansam , Jang Yuyeon , Park Ki-Hoon , Choi Hanul , Nowakowska Aleksandra , Lee Hee-Jung , Kim Minjee , Kang Min-Hee , Kim Jin-Hoi , Shin Ha Youn , Oh Yu-Kyoung , Kim Young Bong
Published: March 2021

Here we report a recombinant baculoviral vector-based DNA vaccine system against Middle East respiratory syndrome coronavirus (MERS-CoV) and the severe acute respiratory syndrome coronavirus-2 (SARS-CoV2). A non-replicating recombinant baculovirus expressing the human endogenous retrovirus envelope gene (AcHERV) was constructed as a DNA vaccine vector for gene delivery into human cells. For MERS-CoV vaccine construction, DNA encoding MERS-CoV S-full, S1 subunit, or receptor-binding domain (RBD) was inserted into the genome of AcHERV. For COVID19 vaccine construction, DNA encoding SARS-CoV2 S-full or S1 or a MERS-CoV NTD domain-fused SARS-CoV2 RBD was inserted into the genome of AcHERV. AcHERV-DNA vaccines induce high humoral and cell-mediated immunity in animal models. In challenge tests, twice immunized AcHERV-MERS-S1 and AcHERV-COVID19-S showed complete protection against MERS-CoV and SARS-CoV2, respectively. Unlike AcHERV-MERS vaccines, AcHERV-COVID19-S provided the greatest protection against SARS-CoV2 challenge. These results support the feasibility of AcHERV-MERS or AcHERV-COVID19 vaccines in preventing pandemic spreads of viral infections.
High turbidity levels alter coral reef fish movement in a foraging task
Authors: Newport Cait , Padget Oliver , de Perera Theresa Burt
Published: March 2021

Sensory systems allow animals to detect and respond to stimuli in their environment and underlie all behaviour. However, human induced pollution is increasingly interfering with the functioning of these systems. Increased suspended sediment, or turbidity, in aquatic habitats reduces the reactive distance to visual signals and may therefore alter movement behaviour. Using a foraging task in which fish (Rhinecanthus aculeatus) had to find six food sites in an aquarium, we tested the impact of high turbidity (40–68 NTU; 154 mg/L) on foraging efficiency using a detailed and novel analysis of individual movements. High turbidity led to a significant decrease in task efficacy as fish took longer to begin searching and find food, and they travelled further whilst searching. Trajectory analyses revealed that routes were less efficient and that fish in high turbidity conditions were more likely to cover the same ground and search at a slower speed. These results were observed despite the experimental protocol allowing for the use of alternate sensory systems (e.g. olfaction, lateral line). Given that movement underlies fundamental behaviours including foraging, mating, and predator avoidance, a reduction in movement efficiency is likely to have a significant impact on the health and population dynamics of visually-guided fish species.