bluuebunny/crossref_metadata_2025 huggingface dataset:
LOTUS, an endogenous Nogo receptor antagonist, is involved in synapse and memory formation
Authors: Nishida Ryohei , Kawaguchi Yuki , Matsubayashi Junpei , Ishikawa Rie , Kida Satoshi , Takei Kohtaro
Published: March 2021

The Nogo signal is involved in impairment of memory formation. We previously reported the lateral olfactory tract usher substance (LOTUS) as an endogenous antagonist of the Nogo receptor 1 that mediates the inhibition of axon growth and synapse formation. Moreover, we found that LOTUS plays an essential role in neural circuit formation and nerve regeneration. However, the effects of LOTUS on synapse formation and memory function have not been elucidated. Here, we clearly showed the involvement of LOTUS in synapse formation and memory function. The cultured hippocampal neurons derived from lotus gene knockout (LOTUS-KO) mice exhibited a decrease in synaptic density compared with those from wild-type mice. We also found decrease of dendritic spine formation in the adult hippocampus of LOTUS-KO mice. Finally, we demonstrated that LOTUS deficiency impairs memory formation in the social recognition test and the Morris water maze test, indicating that LOTUS is involved in functions of social and spatial learning and memory. These findings suggest that LOTUS affects synapse formation and memory function.
Laser-driven proton acceleration from ultrathin foils with nanoholes
Authors: Cantono Giada , Permogorov Alexander , Ferri Julien , Smetanina Evgeniya , Dmitriev Alexandre , Persson Anders , Fülöp Tünde , Wahlström Claes-Göran
Published: March 2021

Structured solid targets are widely investigated to increase the energy absorption of high-power laser pulses so as to achieve efficient ion acceleration. Here we report the first experimental study of the maximum energy of proton beams accelerated from sub-micrometric foils perforated with holes of nanometric size. By showing the lack of energy enhancement in comparison to standard flat foils, our results suggest that the high contrast routinely achieved with a double plasma mirror does not prevent damaging of the nanostructures prior to the main interaction. Particle-in-cell simulations support that even a short scale length plasma, formed in the last hundreds of femtoseconds before the peak of an ultrashort laser pulse, fills the holes and hinders enhanced electron heating. Our findings reinforce the need for improved laser contrast, as well as for accurate control and diagnostics of on-target plasma formation.
Characteristic time in highly motivated movements of children and adults through bottlenecks
Authors: Li Hongliu , Zhang Jun , Xia Long , Yang Libing , Song Weiguo , Yuen Kwok Kit Richard
Published: March 2021

Current codes for fire protection of buildings are mainly based on the movement of adults and neglect the movement characteristic of pre-school children. Having a profound comprehension of the difference between children and adults passing bottlenecks is of great help to improve the safety levels of preschool children. This paper presents an experimental study on the bottleneck flow of pre-school children in a room. The movement characteristics of children’s and adults’ bottleneck flow are investigated with two macroscopic properties: density and speed profiles as well as microscopic characteristic time: motion activation time, relaxation time, exit travel time and time gap. Arch-like density distributions are observed both for highly motivated children and adults, while the distance between the peak density region and the exit location is shorter for children and longer for adults. Children’s movement is less flexible manifested as longer motion activation time and longer relaxation time compared to that of adults. The findings from this study could enhance the understanding of crowd dynamics among the children population and provide supports for the scientific building design for children’s facilities.
Adherent cell remodeling on micropatterns is modulated by Piezo1 channels
Authors: Jetta Deekshitha , Bahrani Fard Mohammad Reza , Sachs Frederick , Munechika Katie , Hua Susan Z.
Published: March 2021

Adherent cells utilize local environmental cues to make decisions on their growth and movement. We have previously shown that HEK293 cells grown on the fibronectin stripe patterns were elongated. Here we show that Piezo1 function is involved in cell spreading. Piezo1 expressing HEK cells plated on fibronectin stripes elongated, while a knockout of Piezo1 eliminated elongation. Inhibiting Piezo1 conductance using GsMTx4 or Gd3+ blocked cell spreading, but the cells grew thin tail-like extensions along the patterns. Images of GFP-tagged Piezo1 showed plaques of Piezo1 moving to the extrusion edges, co-localized with focal adhesions. Surprisingly, in non-spreading cells Piezo1 was located primarily on the nuclear envelope. Inhibiting the Rho-ROCK pathway also reversibly inhibited cell extension indicating that myosin contractility is involved. The growth of thin extrusion tails did not occur in Piezo1 knockout cells suggesting that Piezo1 may have functions besides acting as a cation channel.
HMGB1, anti-HMGB1 antibodies, and ratio of HMGB1/anti-HMGB1 antibodies as diagnosis indicator in fever of unknown origin
Authors: Chen Mingkun , Zhu Li , Xue Miao , Zhu Rongrong , Jing Liling , Wang Huaizhou , Qin Yanghua
Published: March 2021

To evaluate the feasibility of serum HMGB1, anti-HMGB1 antibodies, and HMGB1/anti-HMGB1 ratio as a diagnosis indicator of initial clinical classification in patients with fever of unknown origin (FUO). Ninety-four patients with classical FUO and ninety healthy controls were enrolled in this study. The subjects’ clinical data and serum were collected. The serum concentration of HMGB1 was detected by a commercial HMGB1 ELISA kit, while the serum concentration of anti-HMGB1 antibodies were detected by an in-house built anti-HMGB1 antibodies ELISA kit and further confirmed by immunoblotting. According to the hospital diagnosis on discharge, ninety-four FUO patients were divided into four groups, Infectious disease subgroup, autoimmune disease subgroup, malignant tumor subgroup, and undetermined subgroup. The concentrations of HMGB1 in the infectious disease subgroup and autoimmune disease subgroup were higher than those in the malignant tumor subgroup, undetermined subgroup, and healthy control group. The concentration of anti-HMGB1 antibodies in autoimmune disease subtype group was higher than those in other subgroups as well as healthy control group. According to the distribution of HMGB1 and anti-HMGB1 in scatter plots of the patients with FUO, we found that the ratio of serum HMGB1/anti-HMGB1 is an ideal clinical indicator for differential diagnosis of different subtypes of FUO. The best cut-off was 0.75, and the sensitivity, specificity, and AUC were 66.67%, 87.32%, and 0.8, respectively. Correlation analysis showed that serum concentration of HMGB1 was moderately correlated with CRP in infectious diseases subgroup, and the serum concentration of anti-HMGB1 antibodies was strongly correlated with erythrocyte sedimentation rate in autoimmune disease subgroup. Our study had showed that serum HMGB1/anti-HMGB1 antibodies ratio can help clinicians identify FUO subtypes, thereby avoiding many unnecessary examinations and tests, and improving the effectiveness of clinical diagnosis and treatment of FUO.
Lysyl oxidase engineered lipid nanovesicles for the treatment of triple negative breast cancer
Authors: De Vita Alessandro , Liverani Chiara , Molinaro Roberto , Martinez Jonathan O. , Hartman Kelly A. , Spadazzi Chiara , Miserocchi Giacomo , Taraballi Francesca , Evangelopoulos Michael , Pieri Federica , Bongiovanni Alberto , Mercatali Laura , Tasciotti Ennio , Ibrahim Toni
Published: March 2021

In the field of oncology research, a deeper understanding of tumor biology has shed light on the role of environmental conditions surrounding cancer cells. In this regard, targeting the tumor microenvironment has recently emerged as a new way to access this disease. In this work, a novel extracellular matrix (ECM)-targeting nanotherapeutic was engineered using a lipid-based nanoparticle chemically linked to an inhibitor of the ECM-related enzyme, lysyl oxidase 1 (LOX), that inhibits the crosslinking of elastin and collagen fibers. We demonstrated that, when the conjugated vesicles were loaded with the chemotherapeutic epirubicin, superior inhibition of triple negative breast cancer (TNBC) cell growth was observed both in vitro and in vivo. Moreover, in vivo results displayed prolonged survival, minimal cytotoxicity, and enhanced biocompatibility compared to free epirubicin and epirubicin-loaded nanoparticles. This all-in-one nano-based ECM-targeting chemotherapeutic may provide a key-enabling technology for the treatment of TNBC.
Standardization of the liquid biopsy for pediatric diffuse midline glioma using ddPCR
Authors: Li Daphne , Bonner Erin R. , Wierzbicki Kyle , Panditharatna Eshini , Huang Tina , Lulla Rishi , Mueller Sabine , Koschmann Carl , Nazarian Javad , Saratsis Amanda M.
Published: March 2021

Diffuse midline glioma (DMG) is a highly morbid pediatric brain tumor. Up to 80% of DMGs harbor mutations in histone H3-encoding genes, associated with poor prognosis. We previously showed the feasibility of detecting H3 mutations in circulating tumor DNA (ctDNA) in the liquid biome of children diagnosed with DMG. However, detection of low levels of ctDNA is highly dependent on platform sensitivity and sample type. To address this, we optimized ctDNA detection sensitivity and specificity across two commonly used digital droplet PCR (ddPCR) platforms (RainDance and BioRad), and validated methods for detecting H3F3A c.83A > T (H3.3K27M) mutations in DMG CSF, plasma, and primary tumor specimens across three different institutions. DNA was extracted from H3.3K27M mutant and H3 wildtype (H3WT) specimens, including H3.3K27M tumor tissue (n = 4), CSF (n = 6), plasma (n = 4), and human primary pediatric glioma cells (H3.3K27M, n = 2; H3WT, n = 1). ctDNA detection was enhanced via PCR pre-amplification and use of distinct custom primers and fluorescent LNA probes for c.83 A > T H3F3A mutation detection. Mutation allelic frequency (MAF) was determined and validated through parallel analysis of matched H3.3K27M tissue specimens (n = 3). We determined technical nuances between ddPCR instruments, and optimized sample preparation and sequencing protocols for H3.3K27M mutation detection and quantification. We observed 100% sensitivity and specificity for mutation detection in matched DMG tissue and CSF across assays, platforms and institutions. ctDNA is reliably and reproducibly detected in the liquid biome using ddPCR, representing a clinically feasible, reproducible, and minimally invasive approach for DMG diagnosis, molecular subtyping and therapeutic monitoring.
Quantitative molecular detection of larval Atlantic herring (Clupea harengus) in stomach contents of Atlantic mackerel (Scomber scombrus) marks regions of predation pressure
Authors: Allan Bridie Jean Marie , Ray Jessica Louise , Tiedemann Maik , Komyakova Valeriya , Vikebø Frode , Skaar Katrine Sandnes , Stiasny Martina H. , Folkvord Arild , Nash Richard D. M. , Stenevik Erling Kåre , Kjesbu Olav Sigurd
Published: March 2021

Mortality rates in the early life-history stages of fishes are generally high yet identifying the causes remain unclear. Faltering recruitment rates of Atlantic herring (Clupea harengus) in the Norwegian Sea indicate a need to identify which mortality factors influence larval herring survival. Previous research suggests that increased predation pressure by Atlantic mackerel (Scomber scombrus) may contribute to the disconnect between spawning stock biomass and recruitment. To quantify the contribution of predation pressure by Atlantic mackerel to herring larval mortality, two research cruises were conducted within a probable “hot spot” (67–72° N) for intensified mackerel predation based on particle drift simulations. Mackerel stomach contents were analysed for herring larvae content using droplet digital polymerase chain reaction (ddPCR) with a quantitative molecular detection assay specific for herring. The ddPCR results demonstrate clear predation by mackerel on herring larvae and also suggest that the alternative use of visual examination may give misleading results. Our results show that mackerel should be considered a potentially important predator on herring larvae. The quantitative molecular assay presented here shows great promise as an efficient and specific tool to correctly identify and quantify predation pressure on early life-history stages of fishes.
A collective risk dilemma for tourism restrictions under the COVID-19 context
Authors: Chica Manuel , Hernández Juan M. , Bulchand-Gidumal Jacques
Published: March 2021

The current COVID-19 pandemic has impacted millions of people and the global economy. Tourism has been one the most affected economic sectors because of the mobility restrictions established by governments and uncoordinated actions from origin and destination regions. The coordination of restrictions and reopening policies could help control the spread of virus and enhance economies, but this is not an easy endeavor since touristic companies, citizens, and local governments have conflicting interests. We propose an evolutionary game model that reflects a collective risk dilemma behind these decisions. To this aim, we represent regions as players, organized in groups; and consider the perceived risk as a strict lock-down and null economic activity. The costs for regions when restricting their mobility are heterogeneous, given that the dependence on tourism of each region is diverse. Our analysis shows that, for both large populations and the EU NUTS2 case study, the existence of heterogeneous costs enhances global agreements. Furthermore, the decision on how to group regions to maximize the regions’ agreement of the population is a relevant issue for decision makers to consider. We find out that a layout of groups based on similar costs of cooperation boosts the regions’ agreements and avoid the risk of having a total lock-down and a negligible tourism activity. These findings can guide policy makers to facilitate agreements among regions to maximize the tourism recovery.
Comparison of the RADM2 and RACM chemical mechanisms in O3 simulations: effect of the photolysis rate constant
Authors: Chen Chien-Hung , Chen Tu-Fu , Huang Shang-Ping , Chang Ken-Hui
Published: March 2021

Since the photolysis rate plays an important role in any photoreaction leading to compound sink and radical formation/destruction and eventually O3formation, its impact on the simulated O3concentration was evaluated in the present study. Both RADM2 and RACM were adopted with and without updated photolysis rate constants. The newly developed photolysis rates were determined based on two major absorption cross-section and quantum yield data sources. CMAQ in conjunction with meteorological MM5 and emission data retrieved from Taiwan and East Asia were employed to provide spatial and temporal O3predictions over a one-week period in a three-level nested domain [from 81 km × 81 km in Domain 1 (East Asia) to 9 km × 9 km in Domain 3 (Taiwan)]. Four cases were analyzed, namely, RADM2, with the original photolysis rates applied in Case 1 as a reference case, RADM2, with the updated photolysis rates applied in Case 2, and RACM, with and without the updated photolysis rates applied in Cases 3 and 4, respectively. A comparison of the simulation and observed results indicates that both the application of updated photolysis rate constants and RACM instead of RADM2 enhanced all three error analysis indicators (unpaired peak prediction accuracy, mean normalized bias error and mean absolute normalized gross error). Specifically, RADM2 with the updated photolysis rates resulted in an increase of 12 ppb (10%) in the daily maximum O3concentration in southwestern Taiwan, while RACM without the updated photolysis rates resulted in an increase of 20 ppb (17%) in the daily maximum O3concentration in the same area. When RACM with the updated photolysis rate constants was applied in the air quality model, the difference in the daily maximum O3concentration reached up to 30 ppb (25%). The implication of Case 4 (RACM with the updated photolysis rates) for the formation and degradation of α-pinene and d-limonene was examined.
Simultaneous measurement of free and conjugated estrogens in surface water using capillary liquid chromatography tandem mass spectrometry
Authors: Huang Fan , Karu Kersti , Campos Luiza C.
Published: March 2021

A modified derivatisation-based method allowed for the measurement of free and conjugated estrogens using LC-MS and its application for monitoring compounds of interest in natural water was validated.
Paper-thin multilayer microfluidic devices with integrated valves
Authors: Kim Soohong , Dorlhiac Gabriel , Cotrim Chaves Rodrigo , Zalavadia Mansi , Streets Aaron
Published: March 2021

The “thin-chip” provides the functionality of multilayer PDMS microfluidic devices with integrated valves, in a paper-thin form factor, enabling integration with advanced optical microscopy and magnetic trapping.
Silo discharge of mixtures of soft and rigid grains
Authors: Wang Jing , Fan Bo , Pongó Tivadar , Harth Kirsten , Trittel Torsten , Stannarius Ralf , Illig Maja , Börzsönyi Tamás , Cruz Hidalgo Raúl
Published: March 2021

We study the outflow dynamics and clogging phenomena of mixtures of soft, elastic low-friction spherical grains and hard frictional spheres of similar size in a quasi-two-dimensional (2D) silo with narrow orifice at the bottom.
Advanced cathodes for potassium-ion batteries with layered transition metal oxides: a review
Authors: Li Wen , Bi Zimo , Zhang Wenxin , Wang Jian , Rajagopalan Ranjusha , Wang Qiujun , Zhang Di , Li Zhaojin , Wang Haiyan , Wang Bo
Published: March 2021

The research progress of layered transition metal oxide (LTMO) cathode materials in potassium-ion batteries (PIBs) is summarized. The key technical issues and scientific challenges faced by LTMO cathode materials in PIBs are analyzed.
Autodetachment dynamics of 2-naphthoxide and implications for astrophysical anion abundance
Authors: Ashworth Eleanor K. , Anstöter Cate S. , Verlet Jan R. R. , Bull James N.
Published: March 2021

The first above-threshold resonance of 2-naphthoxide decays through vibrational mode specific autodetachment with a lifetime of 130 ± 10 fs. This state is not a doorway to stable interstellar anion formation.
Reply to the ‘Comment on “Techno-economic analysis of capacitive and intercalative water deionization”’ by S. K. Patel, L. Wang and M. Elimelech, Energy Environ. Sci., 2021, 10.1039/D0EE03321A
Authors: Metzger Michael , Besli Münir , Kuppan Saravanan , Hellstrom Sondra , Kim Soo , Sebti Elias , Subban Chinmayee V. , Christensen Jake
Published: March 2021

This reply provides updated energy consumption estimates at clearly defined separation conditions for electrochemical desalination concepts.
Heterogeneous Ru/TiO2 for hydroaminomethylation of olefins: multicomponent synthesis of amines
Authors: An Jinghua , Gao Zhuyan , Wang Yehong , Zhang Zhixin , Zhang Jian , Li Lu , Tang Bo , Wang Feng
Published: March 2021

Heterogeneous Ru/TiO2-catalyzed HAM reaction of olefins is developed. Various amines can be obtained from olefins. The lower electron density of the Ruδ+ and the higher amount of acid sites of Ru/TiO2, lead to the high HAM reaction activity.
A two‐branch network with pyramid‐based local and spatial attention global feature learning for vehicle re‐identification
Authors: Yang Jucheng , Xing Di , Hu Zhiqiang , Yao Tong
Published: March 2021

In recent years, vehicle re‐identification has attracted more and more attention. How to learn the discriminative information from multi‐view vehicle images becomes one of the challenging problems in vehicle re‐identification field. For example, when the viewpoint of the image changes, the features extracted from one image may be lost in another image. A two‐branch network with pyramid‐based local and spatial attention global feature learning (PSA) is proposed for vehicle re‐identification to solve this issue. Specifically, one branch learns local features at different scales by building pyramid from coarse to fine and the other branch learns attentive global features by using spatial attention module. Subsequently, pooling operation by using global maximum pooling (GMP) for local features and global average pooling (GAP) for global feature is performed. Finally, local feature vectors and global feature vector extracted from the last pooling layer, respectively, are employed for identity re‐identification. The experimental results demonstrate that the proposed method achieves state‐of‐the‐art results on the VeRi‐776 dataset and VehicleID dataset.
SDN‐based intrusion detection system for IoT using deep learning classifier (IDSIoT‐SDL)
Authors: Wani Azka , S Revathi , Khaliq Rubeena
Published: March 2021

The participation of ordinary devices in networking has created a world of connected devices rapidly. The Internet of Things (IoT) includes heterogeneous devices from every field. There are no definite protocols or standards for IoT communication, and most of the IoT devices have limited resources. Enabling a complete security measure for such devices is a challenging task, yet necessary. Many lightweight security solutions have surfaced lately for IoT. The lightweight security protocols are unable to provide an optimum protection against prevailing powerful threats in cyber world. It is also hard to deploy any traditional security protocol on resource‐constrained IoT devices. Software‐defined networking introduces a centralized control in computer networks. SDN has a programmable approach towards networking that decouples control and data planes. An SDN‐based intrusion detection system is proposed which uses deep learning classifier for detection of anomalies in IoT. The proposed intrusion detection system does not burden the IoT devices with security profiles. The proposed work is executed on the simulated environment. The results of the simulation test are evaluated using various matrices and compared with other relevant methods.
Efficient anonymous authentication scheme for automatic dependent surveillance‐broadcast system with batch verification
Authors: Subramani Jegadeesan , Maria Azees , Neelakandan Ramesh Babu , Rajasekaran Arun Sekar
Published: March 2021

Automatic Dependent Surveillance‐Broadcast (ADS‐B) system provides significant improvements in air traffic control system such as optimal routing in non‐radar environments with a new level of safety and efficiency. The ADS‐B system is being installed in many aircrafts in recent year. The ADS‐B equipped aircraft broadcasts the air traffic information to nearby aircraft and ground stations either once or twice per second. Because of the open channel communication atmosphere, the ADS‐B system is affected by many security attacks. Many authentication and batch verification schemes are available to provide data integrity and source authentication for the ADS‐B system. But they are suffering from computational overhead and communication overhead. Hence, an efficient anonymous authentication scheme is proposed for the ADS‐B system with batch verification based on Message Recovery Signature (MRS). The security and performance analysis section ensure that the proposed scheme provides essential security features with less computational and communication overhead comparison with the other existing schemes.
Effect of different coupling agents on the interfacial properties of tube–internally insulated foam materials interface in a composite cross‐arm under water environment
Authors: Liu Yunpeng , Li Le , Liu Hechen , Li Xiaolin , Liu Donggen , Liu Lei , Tang Li , Zhou Songsong
Published: March 2021

In recent years, electrical breakdown accidents for composite cross‐arms in rain‐impacted environments have occurred which might be ascribed to the degradation of the tube–internally insulated foam materials interface. This research has focused on the different coupling agent treatments (KH‐550, KH‐560, KH‐792, and IPTS) of the tube–internally insulated foam materials interface. The effect of different coupling agents on the interfacial electrical and physical properties in a water environment have been studied. The leakage current and compressive shear strength of the interface were investigated after water diffusion pre‐stress. Three‐dimensional computed tomography (μCT) was used to study the interface cross‐section tomogram, interface three‐dimensional volume rendering, and relative interface porosity. The interfacial hydrolysis resistance ability and the interfacial strength modified by various coupling agents were effectively reflected by the compressive shear strength and relatively defect ratio. The results revealed the ranking of the comprehensive coupling effect was KH‐560>KH‐550>KH‐792>IPTS, which provides significant guidance for modifying internal insulation interface performance for composite cross‐arms.
Wind-envelope interaction as the origin of the slow cyclic brightness variations of luminous blue variables
Authors: Grassitelli L. , Langer N. , Mackey J. , Gräfener G. , Grin N. J. , Sander A. A. C. , Vink J. S.
Published: March 2021

Luminous blue variables (LBVs) are hot, very luminous massive stars displaying large quasi-periodic variations in brightness, radius, and photospheric temperature on timescales of years to decades. The physical origin of this variability, called S Doradus cycle after its prototype, has remained elusive. We study the feedback of stellar wind mass-loss on the envelope structure in stars near the Eddington limit. We calculated a time-dependent hydrodynamic stellar evolution, applying a stellar wind mass-loss prescription with a temperature dependence inspired by the predicted systematic increase in mass-loss rates below 25 kK. We find that when the wind mass-loss rate crosses a well-defined threshold, a discontinuous change in the wind base conditions leads to a restructuring of the stellar envelope. The induced drastic radius and temperature changes, which occur on the thermal timescale of the inflated envelope, in turn impose mass-loss variations that reverse the initial changes, leading to a cycle that lacks a stationary equilibrium configuration. Our proof-of-concept model broadly reproduces the typical observational phenomenology of the S Doradus variability. We identify three key physical ingredients that are required to trigger the instability: inflated envelopes in close proximity to the Eddington limit, a temperature range where decreasing opacities do not lead to an accelerating outflow, and a mass-loss rate that increases with decreasing temperature, crossing a critical threshold value within this temperature range. Our scenario and model provide testable predictions, and open the door for a consistent theoretical treatment of the LBV phase in stellar evolution, with consequences for their further evolution as single stars or in binary systems.
A unified scenario for the origin of spiral and elliptical galaxy structural scaling laws
Authors: Ferrero Ismael , Navarro Julio F. , Abadi Mario G. , Benavides José A. , Mast Damián
Published: March 2021

Elliptical (E) and spiral (S) galaxies follow tight, but different, scaling laws that link their stellar masses, radii, and characteristic velocities. Mass and velocity, for example, scale tightly in spirals with little dependence on galaxy radius (the ‘Tully-Fisher relation’; TFR). On the other hand, ellipticals appear to trace a 2D surface in size-mass-velocity space (the ‘Fundamental Plane’; FP). Over the years, a number of studies have attempted to understand these empirical relations, usually in terms of variations of the virial theorem for E galaxies and in terms of the scaling relations of dark matter halos for spirals. We use Lambda cold dark matter (ΛCDM) cosmological hydrodynamical simulations to show that the scaling relations of both ellipticals and spirals arise as the result of (i) a tight galaxy mass–dark halo mass relation and (ii) the self-similar mass profile of cold dark matter halos. In this interpretation, E and S galaxies of a given stellar mass inhabit halos of similar masses, and their different scaling laws result from the varying amounts of dark matter enclosed within their luminous radii. This scenario suggests a new galaxy distance indicator applicable to galaxies of all morphologies and provides simple and intuitive explanations for long-standing puzzles, such as why the TFR is independent of surface brightness, or what causes the ‘tilt’ in the FP. Our results provide strong support for the predictions of ΛCDM in the strongly non-linear regime, as well as guidance for further improvements to cosmological simulations of galaxy formation.
Radial evolution of the April 2020 stealth coronal mass ejection between 0.8 and 1 AU
Authors: Freiherr von Forstner Johan L. , Dumbović Mateja , Möstl Christian , Guo Jingnan , Papaioannou Athanasios , Elftmann Robert , Xu Zigong , Christoph Terasa Jan , Kollhoff Alexander , Wimmer-Schweingruber Robert F. , Rodríguez-Pacheco Javier , Weiss Andreas J. , Hinterreiter Jürgen , Amerstorfer Tanja , Bauer Maike , Belov Anatoly V. , Abunina Maria A. , Horbury Timothy , Davies Emma E. , O’Brien Helen , Allen Robert C. , Bruce Andrews G. , Berger Lars , Boden Sebastian , Cernuda Cangas Ignacio , Eldrum Sandra , Espinosa Lara Francisco , Gómez Herrero Raúl , Hayes John R. , Ho George C. , Kulkarni Shrinivasrao R. , Jeffrey Lees W. , Martín César , Mason Glenn M. , Pacheco Daniel , Prieto Mateo Manuel , Ravanbakhsh Ali , Rodríguez Polo Oscar , Sánchez Prieto Sebastián , Schlemm Charles E. , Seifert Helmut , Tyagi Kush , Yedla Mahesh
Published: March 2021

Aims.We present observations of the first coronal mass ejection (CME) observed by the Solar Orbiter spacecraft on April 19, 2020 and the associated Forbush decrease (FD) measured by the High Energy Telescope (HET). This CME is a multi-spacecraft event that was also seen near Earth the following day.

Methods.We highlight the capabilities of the HET for observing small short-term variations of the galactic cosmic ray count rate using its single detector counters. We applied the analytical ForbMod model to the FD measurements to reproduce the Forbush decrease at both locations. Input parameters for the model were derived from both in situ and remote-sensing observations of the CME.

Results.The very slow (∼350 km s−1) stealth CME caused an FD with an amplitude of 3% in the low-energy cosmic ray measurements at HET and 2% in a comparable channel of the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on board the Lunar Reconnaissance Orbiter, as well as a 1% decrease in neutron monitor measurements. Significant differences are observed in the expansion behavior of the CME at different locations, which may be related to influence of the following high speed solar wind stream. Under certain assumptions, ForbMod is able to reproduce the observed FDs in low-energy cosmic ray measurements from HET as well as CRaTER, however, with the same input parameters, the results do not agree with the FD amplitudes at higher energies measured by neutron monitors on Earth. We study these discrepancies and provide possible explanations.

Conclusions.This study highlights the notion that the novel measurements of Solar Orbiter can be coordinated with observations from other spacecraft to improve our understanding of space weather in the inner heliosphere. Multi-spacecraft observations combined with data-based modeling are also essential for understanding the propagation and evolution of CMEs, in addition to their space weather impacts.
Spatially resolved spectroscopy across stellar surfaces
Authors: Dravins Dainis , Ludwig Hans-Günter , Freytag Bernd
Published: March 2021

Context. High-precision stellar analyses require hydrodynamic 3D modeling. Such models predict changes across stellar disks of spectral line shapes, asymmetries, and wavelength shifts. For testing models in stars other than the Sun, spatially resolved observations are feasible from differential spectroscopy during exoplanet transits, retrieving spectra of those stellar surface segments that successively become hidden behind the transiting planet, as demonstrated in Papers I, II, and III.

Aims. Synthetic high-resolution spectra over extended spectral regions are now available from 3D models. Similar to other ab initio simulations in astrophysics, these data contain patterns that have not been specifically modeled but may be revealed after analyses to be analogous to those of a large volume of observations.

Methods. From five 3D models spanning Teff = 3964–6726 K (spectral types ~K8 V–F3 V), synthetic spectra at hyper-high resolution (λ/Δλ >1 000 000) were analyzed. Selected Fe I and Fe II lines at various positions across stellar disks were searched for characteristic patterns between different types of lines in the same star and for similar lines between different stars.

Results. Spectral-line patterns are identified for representative photospheric lines of different strengths, excitation potentials, and ionization levels, thereby encoding the hydrodynamic 3D structure. Line profiles and bisectors are shown for various stars at different positions across stellar disks. Absolute convective wavelength shifts are obtained as differences to 1D models, where such shifts do not occur.

Conclusions. Observable relationships for line properties are retrieved from realistically complex synthetic spectra. Such patterns may also test very detailed 3D modeling, including non-LTE effects. While present results are obtained at hyper-high spectral resolution, the subsequent Paper V examines their practical observability at realistically lower resolutions, and in the presence of noise.
Ultrasonic spray pyrolysis technique to generate a solar absorber coating of Mn-doped α-Fe2O3
Authors: Hernández-Pérez Carlos David , Barrera-Calva Enrique , González Federico , Rentería Tapia Victor
Published: March 2021

Today, even though exist a Titanium Nitride Oxide, TiNOX, a very good commercial solar absorber, the efforts to develop new and better solar absorbers like TiNOX are continuing in several laboratories all over the world. In this article, we used the ultrasonic spray pyrolysis technique to prepare manganese, Mn, Mn-doped α-Fe2O3 dark thin films deposited on titanium substrates. The results of an analysis of the solar absorptance and thermal emittance of these films are also presented here; the optical properties depend of the proportions of Mn and iron, Fe, in the spray solution and of the deposit temperature. The best solar absorptance (0.94) and thermal emittance (0.07) values of the films prepared at 600 °C for iron and manganese ion with concentrations of 0.0015 and 0.0035 mol/l, respectively, are comparable with the optical properties of the Titanium Nitride oxide, TiNOX, a very common commercial solar absorber used as an efficient coating for flat plate solar collectors industry.
Gender and age-based investor affinities in a Ponzi scheme
Authors: Huang Li , Li Oliver Zhen , Lin Yupeng , Xu Chao , Xu Haoran
Published: March 2021

Utilizing a police dataset of a fundraising Ponzi scheme in China, we establish referrer-investor links and examine how investor affinity in terms of gender and age affects the way the scheme spreads and the way investors suffer losses. We find that female or older investors are more susceptible to investor affinity. Specifically, female or older investors are more likely to be referred into the scheme by female or older investors. Female or older investors tend to occupy lower layers in the investor hierarchy of the scheme and they are more likely to occupy lower layers if they are referred into the scheme by female or older investors. Consequently, female or older investors suffer more losses if they are referred into the scheme by female or older investors. We conclude that gender and age-based investor affinities are especially pronounced among female or older investors in a Ponzi scheme.
Geographic tongue as a reaction–diffusion system
Authors: McGuire Margaret K. , Fuller Chase A. , Lindner John F. , Manz Niklas
Published: March 2021

Geographic tongue or benign migratory glossitis is a condition of an unknown cause characterized by chronic lesions that slowly migrate across the surface of the tongue. The condition’s characteristic wavefronts suggest that it can be modeled as a reaction–diffusion system. Here, we present a model for geographic tongue pattern evolution using reaction–diffusion equations applied to portions of spheroids and paraboloids that approximate a tongue shape. We demonstrate that the observed patterns of geographic tongue lesions can be explained by propagating reaction–diffusion waves on these variably curved surfaces.
Left-covariant first order differential calculus on quantum Hopf supersymmetry algebra
Authors: Fakhri H. , Laheghi S.
Published: March 2021

We introduce a Hopf algebra structure on the N = 2 quantum supersymmetry algebra and formulate a first order quantum differential calculus on it. Then, it is enhanced to three *-calculi by defining three appropriate involution maps on the quantum super-algebra. Two of the *-structures correspond to quantum complex super-algebra and the other correspond to a quantum real one. An appropriate quantum super-Hopf algebra including two even and two odd generators and also its corresponding quantum super-group are introduced. Compared to the quantum super-algebra, the quantum super-group also has three different *-structures. It is shown that the differential calculus over the quantum super-algebra is left-covariant with respect to the quantum super-group. Besides, it is shown that the graded differential algebra for the case q = 1 is a bicovariant bimodule over the undeformed Hopf supersymmetry algebra.
Adsorption-controlled growth of Ga2O3 by suboxide molecular-beam epitaxy
Authors: Vogt Patrick , Hensling Felix V. E. , Azizie Kathy , Chang Celesta S. , Turner David , Park Jisung , McCandless Jonathan P. , Paik Hanjong , Bocklund Brandon J. , Hoffman Georg , Bierwagen Oliver , Jena Debdeep , Xing Huili G. , Mou Shin , Muller David A. , Shang Shun-Li , Liu Zi-Kui , Schlom Darrell G.
Published: March 2021

This paper introduces a growth method—suboxide molecular-beam epitaxy (S-MBE)—which enables a drastic enhancement in the growth rates of Ga2O3 and related materials to over 1 μm h−1 in an adsorption-controlled regime, combined with excellent crystallinity. Using a Ga + Ga2O3 mixture with an oxygen mole fraction of x(O) = 0.4 as an MBE source, we overcome kinetic limits that had previously hampered the adsorption-controlled growth of Ga2O3 by MBE. We present growth rates up to 1.6 μm h−1 and 1.5 μm h−1 for Ga2O3/Al2O3 and Ga2O3/Ga2O3 structures, respectively, with very high crystalline quality at unparalleled low growth temperature for this level of perfection. We combine thermodynamic knowledge of how to create molecular beams of targeted suboxides with a kinetic model developed for the S-MBE of III–VI compounds to identify appropriate growth conditions. Using S-MBE, we demonstrate the growth of phase-pure, smooth, and high-purity homoepitaxial Ga2O3 films that are thicker than 4.5 μm. With the high growth rate of S-MBE, we anticipate a significant improvement to vertical Ga2O3-based devices. We describe and demonstrate how this growth method can be applied to a wide range of oxides. With respect to growth rates and crystalline quality, S-MBE rivals leading synthesis methods currently used for the production of Ga2O3-based devices.
Thickness-dependent quantum transport of Weyl fermions in ultra-high-quality SrRuO3 films
Authors: Kaneta-Takada Shingo , Wakabayashi Yuki K. , Krockenberger Yoshiharu , Ohya Shinobu , Tanaka Masaaki , Taniyasu Yoshitaka , Yamamoto Hideki
Published: March 2021

The recent observation of Weyl fermions in the itinerant 4d ferromagnetic perovskite SrRuO3 points to this material being a good platform for exploring novel physics related to a pair of Weyl nodes in epitaxial heterostructures. In this Letter, we report the thickness-dependent magnetotransport properties of ultra-high-quality epitaxial SrRuO3 films grown under optimized conditions on SrTiO3 substrates. Signatures of Weyl fermion transport, i.e., unsaturated linear positive magnetoresistance accompanied by a quantum oscillation having a high quantum mobility of 10 000 cm2/V s and a π Berry phase, were observed in films with thicknesses as small as 10 nm. Residual resistivity increased with the decreasing film thickness indicating disorder near the interface between SrRuO3 and the SrTiO3 substrate. Since this disorder affects the magnetic and electrical properties of the films, the Curie temperature decreases and the coercive field increases with the decreasing thickness. Thickness-dependent magnetotransport measurements revealed that the threshold residual resistivity ratio to observe Weyl fermion transport is 21. These results provide guidelines for realizing quantum transport of Weyl fermions in SrRuO3 near heterointerfaces.
A generalization of the Lagrange–Hamilton formalism with application to non-conservative systems and the quantum to classical transition
Authors: Langley R. S.
Published: March 2021

This work has two aims. The first is to develop a Lagrange–Hamilton framework for the analysis of multi-degree-of-freedom nonlinear systems in which non-conservative effects are included in the variational principle of least action from the outset. The framework is a generalization of the Bateman approach in which a set of adjoint coordinates is introduced. A function termed the M-function is introduced as the Fourier transform over the momenta of the joint probability density function (JPDF) of the displacements and momenta, and it is shown that for statistical systems, this function can be written as an expectation involving the new principle function and a general dimensional constant ℏ. This leads to a concise derivation of the Fokker–Planck–Kolmogorov equation. It is found that the equation governing the M-function can be expressed in terms of the new Hamiltonian by replacing momenta by differential operators, meaning that the function satisfies the same equation as the quantum wave function. This gives rise to the second aim of this work: to explore relations between the developed classical framework and quantum mechanics. It is shown that for an undamped linear system, the solution of the M-function equation yields the response JPDF as a sum of Wigner functions. This classical analysis leads to a number of well-known results from quantum mechanics as ℏ → 0, and the extension of this result to nonlinear systems is discussed. The quantum wave function associated with the Hamiltonian is then considered, and the relevance of this function to the physical system is discussed.
Recent advances in bubble-based technologies: Underlying interaction mechanisms and applications
Authors: Qiao Chenyu , Yang Diling , Mao Xiaohui , Xie Lei , Gong Lu , Peng Xuwen , Peng Qiongyao , Wang Tao , Zhang Hao , Zeng Hongbo
Published: March 2021

Gas bubbles widely exist in nature and numerous industrial processes. The physicochemical characteristics of bubbles such as large specific surface area, low density, and hydrophobicity make them an ideal platform for developing colloidal and interfacial technologies. Over the past few decades, much effort has been devoted to investigating the properties and behaviors of bubbles and their applications. A series of bubble-based technologies (BBTs) have been developed, which have attracted increasing attention and shown great importance in a wide range of engineering, material, and biological fields. These BBTs, such as bubble flotation and the bubble-liposome system, provide feasible and promising solutions to mineral separation, material assembling, medical diagnosis, and drug delivery. In this work, we have systematically reviewed the physicochemical characteristics of bubbles and how to modulate their behaviors in complex fluid systems, as well as the underlying fundamental interaction mechanisms of bubbles in related BBTs. Advanced nanomechanical techniques such as atomic force microscopy, which are used to quantify the interaction mechanisms in bubble-containing systems, have been introduced. The effects of various influential factors on the bubble behaviors are discussed, which provide potential approaches to improve the controllability and performance of BBTs. The recent advances in the applications of selected BBTs in engineering, biomedical, and material areas are presented. Some remaining challenging issues and perspectives for future studies have also been discussed. This review improves the fundamental understanding of characteristics and surface interaction mechanisms of bubbles, with useful implications for developing advanced BBTs.
Climate network approach reveals the modes of CO2 concentration to surface air temperature
Authors: Ying Na , Wang Weiping , Fan Jingfang , Zhou Dong , Han Zhangang , Chen Qinghua , Ye Qian , Xue Zhigang
Published: March 2021

Increasing atmospheric carbon dioxide (CO2) is expected to be the main factor of global warming. The relation between CO2 concentrations and surface air temperature (SAT) has been found related to Rossby waves based on a multi-layer complex network approach. However, the significant relations between CO2 and SAT occur in the South Hemisphere that is not that much influenced by human activities may offer not enough information to formulate targeted carbon reduction policies. Here, we address it by removing the effects of the Rossby waves to reconstruct CO2 concentrations and SAT multi-layer complex network. We uncover that the CO2 concentrations are strongly associated with the surrounding SAT regions. The influential regions of CO2 on SAT occur over eastern Asia, West Asia, North Africa, the coast of North American, and Western Europe. It is shown that CO2 over Siberia in phase with the SAT variability in eastern East Asia. Indeed, CO2 concentration variability is causing effects on the recent warming of SAT in some middle latitude regions. Furthermore, sensitive parameters that CO2 impacts SAT of top 15 carbon emissions countries have been identified. These countries are significantly responsible for global warming, giving implications for carbon emissions reductions. The methodology and results presented here not only facilitate further research in regions of increased sensitivity to the warming resulting from CO2 concentrations but also can formulate strategies and countermeasures for carbon emission and carbon reduction.
Unified mechanism of inverse stochastic resonance for monostability and bistability in Hindmarsh–Rose neuron
Authors: Zhu Jinjie
Published: March 2021

Noise is ubiquitous and has been verified to play constructive roles in various systems, among which the inverse stochastic resonance (ISR) has aroused much attention in contrast to positive effects such as stochastic resonance. The ISR has been observed in both bistable and monostable systems for which the mechanisms are revealed as noise-induced biased switching and noise-enhanced stability, respectively. In this paper, we investigate the ISR phenomenon in the monostable and bistable Hindmarsh–Rose neurons within a unified framework of large deviation theory. The critical noise strengths for both cases can be obtained by matching the timescales between noise-induced boundary crossing and the limit cycle. Furthermore, different stages of ISR are revealed by the bursting frequency distribution, where the gradual increase of the peak bursting frequency can also be explained within the same framework. The perspective and results in this paper may shed some light on the understanding of the noise-induced complex phenomena in stochastic dynamical systems.