bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrocardiogram-based mortality prediction in patients with COVID-19 using machine learning
Authors: van de Leur R. R. , Bleijendaal H. , Taha K. , Mast T. , Gho J. M. I. H. , Linschoten M. , van Rees B. , Henkens M. T. H. M. , Heymans S. , Sturkenboom N. , Tio R. A. , Offerhaus J. A. , Bor W. L. , Maarse M. , Haerkens-Arends H. E. , Kolk M. Z. H. , van der Lingen A. C. J. , Selder J. J. , Wierda E. E. , van Bergen P. F. M. M. , Winter M. M. , Zwinderman A. H. , Doevendans P. A. , van der Harst P. , Pinto Y. M. , Asselbergs F. W. , van Es R. , Tjong F. V. Y. ,   the CAPACITY-COVID collaborative consortium
Published: March 2022

Background and purpose

The electrocardiogram (ECG) is frequently obtained in the work-up of COVID-19 patients. So far, no study has evaluated whether ECG-based machine learning models have added value to predict in-hospital mortality specifically in COVID-19 patients.

Methods

Using data from the CAPACITY-COVID registry, we studied 882 patients admitted with COVID-19 across seven hospitals in the Netherlands. Raw format 12-lead ECGs recorded within 72 h of admission were studied. With data from five hospitals (n = 634), three models were developed: (a) a logistic regression baseline model using age and sex, (b) a least absolute shrinkage and selection operator (LASSO) model using age, sex and human annotated ECG features, and (c) a pre-trained deep neural network (DNN) using age, sex and the raw ECG waveforms. Data from two hospitals (n = 248) was used for external validation.

Results

Performances for models a, b and c were comparable with an area under the receiver operating curve of 0.73 (95% confidence interval [CI] 0.65–0.79), 0.76 (95% CI 0.68–0.82) and 0.77 (95% CI 0.70–0.83) respectively. Predictors of mortality in the LASSO model were age, low QRS voltage, ST depression, premature atrial complexes, sex, increased ventricular rate, and right bundle branch block.

Conclusion

This study shows that the ECG-based prediction models could be helpful for the initial risk stratification of patients diagnosed with COVID-19, and that several ECG abnormalities are associated with in-hospital all-cause mortality of COVID-19 patients. Moreover, this proof-of-principle study shows that the use of pre-trained DNNs for ECG analysis does not underperform compared with time-consuming manual annotation of ECG features.
Anisotropic, biomorphic cellular Si3N4 ceramics with directional well-aligned nanowhisker arrays based on wood-mimetic architectures
Authors: Xu Songsong , Zhou Xiaonan , Zhi Qiang , Gao Junjie , Hao Liucheng , Shi Zhongqi , Wang Bo , Yang Jianfeng , Ishizaki Kozo
Published: March 2022

Inspired by the transport behavior of water and ions through the aligned channels in trees, we demonstrate a facile, scalable approach for constructing biomorphic cellular Si3N4ceramic frameworks with well-aligned nanowhisker arrays on the surface of directionally aligned microchannel alignments. Through a facile Y(NO3)3solution infiltration into wood-derived carbon preforms and subsequent heat treatment, we can faultlessly duplicate the anisotropic wood architectures into free-standing bulk porous Si3N4ceramics. Firstly, α-Si3N4microchannels were synthesized on the surface of CB-templates via carbothermal reduction nitridation (CRN). And then, homogeneous distributed Y−Si−O−N liquid phase on the walls of microchannel facilitated the anisotropic β-Si3N4grain growth to form nanowhisker arrays. The dense aligned microchannels with low-tortuosity enable excellent load carrying capacity and thermal conduction through the entire materials. As a result, the porous Si3N4ceramics exhibited an outstanding thermal conductivity (TC,kR≈ 6.26 W·m−1·K−1), a superior flexural strength (σL≈ 29.4 MPa), and a relative high anisotropic ratio of TC (kR/kL= 4.1). The orientation dependence of the microstructure-property relations may offer a promising perspective for the fabrication of multifunctional ceramics.
One-step method to enhance biotribological properties and biocompatibility of DLC coating by ion beam irradiation
Authors: Liu Yuzhen , Zhang Kelun , Han Jae-Ho , Hwang Youn-Hoo , Xu Shusheng , Kim Dae-Eun
Published: March 2022

A one-step method was developed to create a highly biocompatible micropatterned surface on a diamond-like carbon (DLC) through irradiation with a nitrogen ion beam and thus enhance the biocompatibility of osseointegrated surfaces and biotribological performance of articular surfaces. The biocompatibility and biotribological mechanisms were analyzed in terms of the structure and morphology of DLC. It was demonstrated that a layer enriched in sp3C−N bonds was formed on the surface of the DLC after nitrogen ion beam irradiation. Moreover, with an increase in the radiation dose, the content of sp3C−N on the DLC surface increased significantly, and the biocompatibility was positively correlated with it. The adhesion of the MC3T3 osteoblasts increased significantly from 32% to 86% under an irradiation dose of 8 × 1015ions/cm2. In contrast, the micropattern had a significant negative effect on the adhesion of the osteoblasts as it physically hindered cell expansion and extension. The micropattern with a depth of 37 nm exhibited good friction properties, and the coefficient of friction was reduced by 21% at relatively high speeds.
Polynomial Methods and Incidence Theory
Authors: Sheffer Adam
Published: March 2022

The past decade has seen numerous major mathematical breakthroughs for topics such as the finite field Kakeya conjecture, the cap set conjecture, Erdős's distinct distances problem, the joints problem, as well as others, thanks to the introduction of new polynomial methods. There has also been significant progress on a variety of problems from additive combinatorics, discrete geometry, and more. This book gives a detailed yet accessible introduction to these new polynomial methods and their applications, with a focus on incidence theory. Based on the author's own teaching experience, the text requires a minimal background, allowing graduate and advanced undergraduate students to get to grips with an active and exciting research front. The techniques are presented gradually and in detail, with many examples, warm-up proofs, and exercises included. An appendix provides a quick reminder of basic results and ideas.
Update on the role of extracellular vesicles in rheumatoid arthritis
Authors: Miao Hai-bing , Wang Fang , Lin Shu , Chen Zhen
Published: March 2022

Rheumatoid arthritis (RA) is a heterogeneous autoimmune disorder that leads to severe joint deformities, negatively affecting the patient's quality of life. Extracellular vesicles (EVs), which include exosomes and ectosomes, act as intercellular communication mediators in several physiological and pathological processes in various diseases including RA. In contrast, EVs secreted by mesenchymal stem cells perform an immunomodulatory function and stimulate cartilage repair, showing promising therapeutic results in animal models of RA. EVs from other sources, including dendritic cells, neutrophils and myeloid-derived suppressor cells, also influence the biological function of immune and joint cells. This review describes the role of EVs in the pathogenesis of RA and presents evidence supporting future studies on the therapeutic potential of EVs from different sources. This information will contribute to a better understanding of RA development, as well as a starting point for exploring cell-free-based therapies for RA.
Building Resilience Against ViolencE (BRAVE): protocol of a parenting intervention for mothers and fathers with post-traumatic stress disorder in Pakistan
Authors: Chaudhry Nasim , Farooque Sana , Kiran Tayyeba , Eylem-van Bergeijk Ozlem , Chaudhry Imran B. , Memon Rakhshi , Husain Mina , Andriopoulou Panoraia , Hussain Rana Mowadat , Naeem Farooq , Husain Nusrat
Published: March 2022

Background

Prevalence of post-traumatic stress disorder (PTSD) is high in Pakistan both due to natural disasters and ongoing conflicts. Offspring of trauma survivors are at increased risk for mental and physical illnesses. Parental PTSD has been linked to troubled parent–child relationships, behaviour problems, trauma symptoms, and depression in children. This study aims to explore the acceptability, feasibility and indications of the effectiveness of group learning through play plus trauma-focused cognitive behaviour therapy (LTP Plus TF-CBT) for parents experiencing PTSD.

Methods/Design

This is a two-arm pilot cluster randomised controlled trial (RCT). We aim to recruit 300 parents with a diagnosis of PTSD. The screening will be done using the Impact of Event Scale-Revised. Diagnosis of PTSD will be confirmed using the Clinician-Administered PTSD Scale-5 (CAPS-5). Union Councils from Peshawar and Karachi will be randomised into either group LTP Plus TF CBT arm or treatment as usual (TAU). The intervention includes 12 sessions of LTP Plus TF-CBT delivered weekly in the first 2 months and then fortnightly in a group setting by trained psychologists. The groups will be co-facilitated by the community health workers (CHWs). Parents will be assessed at baseline and 4th month (end of the intervention), using the Patient Health Questionnaire (PHQ-9), Generalised Anxiety Disorder (GAD-7) Scale, Client Service Receipt Inventory (CSRI), and Ages and Stages Questionnaire (ASQ-3)

Discussion

This trial would help build an understanding of the acceptability, feasibility and indications of the effectiveness of a low-cost parenting intervention.
Performative Diplomacy: Iran–Republic of China Relations, 1920–1949
Authors: Figueroa William A.
Published: March 2022

This article seeks to fill a gap in the literature by sketching a narrative of Republic of China–Iran relations between 1920 and 1949. It analyzes the factors behind Sino-Iranian cooperation and competition in the tea and silk trades and at the League of Nations. Unofficial commercial interests, including Iranian merchants in Shanghai, played a larger role than previously thought in driving the establishment of the Sino-Persian Treaty of 1920. After ratifying the treaty in 1922, the Republic of China established an Iranian consulate in Shanghai in 1934. Diplomacy between the two nations, and the public ceremonies performed by foreign diplomats in Shanghai, were part of a pattern of performative nationalist diplomacy undertaken by both the Chinese and Iranian states.
Analysis of the onset and evolution of a dynamic stall vortex on a periodic plunging aerofoil
Authors: Miotto Renato , Wolf William , Gaitonde Datta , Visbal Miguel
Published: March 2022

The onset and evolution of the dynamic stall vortex (DSV) are analysed by means of large eddy simulations of an SD7003 aerofoil undergoing periodic plunging motion in a transitional Reynolds number flow ($Re =6\times 10^{4}$). Interactions between upstream propagating Kelvin–Helmholtz instabilities and a shear layer formed at the leading edge trigger flow separation. The former appear to be related to acoustic waves scattered at the trailing edge due to initial vortex shedding. Two freestream Mach numbers ($M_{\infty }=0.1$and$0.4$) are employed to examine the flow differences due to compressibility variations. The existence of a common timing for the acoustic perturbations in both flows suggests a possible Mach number invariance for the birth of the Kelvin–Helmholtz instability. Increasing compressibility, however, induces earlier spanwise fluctuations, higher flow three-dimensionality and a weaker and more diffuse DSV, which is formed further downstream of the leading edge and has lower residency time. In order to better characterize the onset of the DSV, two empirical criteria are assessed: the leading edge suction parameter and the chord-normal shear layer height. Results demonstrate a higher robustness of the latter with respect to Mach number variations. Modal decomposition, performed with both the classical dynamic mode decomposition (DMD) and its multi-resolution variant (mrDMD), highlights key trends and demonstrates the capacity of the mrDMD to extract physically meaningful flow structures related to the stall onset. Such detailed characterization of the shear layer can be used for a systematic exploration of flow control strategies for unsteady aerofoils.
Resistance and mobility functions for the near-contact motion of permeable particles
Authors: Reboucas Rodrigo B. , Loewenberg Michael
Published: March 2022

A lubrication analysis is presented for the resistances between permeable spherical particles in near contact,$h_0/a\ll 1$, where$h_0$is the minimum separation between the particles, and$a=a_1 a_2/(a_1+a_2)$is the reduced radius. Darcy's law is used to describe the flow inside the permeable particles and no-slip boundary conditions are applied at the particle surfaces. The weak permeability regime$K=k/a^{2} \ll 1$is considered, where$k=\frac {1}{2}(k_1+k_2)$is the mean permeability. Particle permeability enters the lubrication resistances through two functions of$q=K^{-2/5}h_0/a$, one describing axisymmetric motions, the other transverse. These functions are obtained by solving an integral equation for the pressure in the near-contact region. The set of resistance functions thus obtained provide the complete set of near-contact resistance functions for permeable spheres and match asymptotically to the standard hard-sphere resistances that describe pairwise hydrodynamic interactions away from the near-contact region. The results show that permeability removes the contact singularity for non-shearing particle motions, allowing rolling without slip and finite separation velocities between touching particles. Axisymmetric and transverse mobility functions are presented that describe relative particle motion under the action of prescribed forces and in linear flows. At contact, the axisymmetric mobility under the action of oppositely directed forces is$U/U_0=d_0K^{2/5}$, where$U$is the relative velocity,$U_0$is the velocity in the absence of hydrodynamic interactions and$d_0=1.332$. Under the action of a constant tangential force, a particle in contact with a permeable half-space rolls without slipping with velocity$U/U_0=d_1(d_2+\log K^{-1})^{-1}$, where$d_1=3.125$and$d_2=6.666$; in shear flow, the same expression holds with$d_1=7.280$.
Levels of dietary diversity and its associated factors among children aged 6–23 months in West Shoa, Ethiopia: a comparative cross-sectional study
Authors: Belete Kefyalew T. , Daba Derese B. , Shallo Seifadin A. , Yebassa Mecha A. , Danusa Kababa T. , Gadisa Diriba A.
Published: March 2022

Dietary diversity is one of the eight core indicators of infant and young child feeding (IYCF) practices. It is also a proxy for nutrient adequacy of the diet of individuals. There are minimal studies showing the level of dietary practice in urban and rural settings comparably. Hence, the present study intended to assess and compare differences in the level of dietary diversity and its contributing factors in urban and rural settings of the West Shoa zone of Oromia, Ethiopia. A community-based comparative cross-sectional study was conducted among 674 pairs of mothers/caregivers and children aged 6–23 months using a multistage sampling technique. Data were analysed and descriptive summaries were presented with tables, charts and graphs. A linear regression analysis was used to identify factors that were associated with the level of dietary diversity. The dietary diversity score (DDS) was 26⋅1 % (95 % CI 22⋅8, 29⋅5) both in urban and rural (P < 0⋅001), and also the minimum meal frequency was 56⋅5 % (95 % CI 52⋅7, 60⋅2) (P < 0⋅038). Child from merchant mother, own production of foods at the household level and frequent advice of IYCF practices during Post natal care (PNC) visit in urban residents, maternal secondary educational level, living with caregiver only, having a merchant father, advice of IYCF practice during PNC visit and utilisation of horse as a means of transportation in rural were positively associated with the level of dietary diversity. Generally, infant and young children who received the recommended dietary diversity and the minimum meal frequency were low in the study area both in the urban and rural settings.
Rabbit Endothelial Progenitor Cells Derived From Peripheral Blood and Bone Marrow: An Ultrastructural Comparative Study
Authors: Duranova Hana , Valkova Veronika , Olexikova Lucia , Radochova Barbora , Balazi Andrej , Chrenek Peter , Vasicek Jaromir
Published: March 2022

The present study was designed to compare the ultrastructure of early endothelial progenitor cells (EPCs) derived from rabbit peripheral blood (PB-EPCs) and bone marrow (BM-EPCs). After the cells had been isolated and cultivated up to passage 3, microphotographs obtained from transmission electron microscope were evaluated from qualitative and quantitative (unbiased stereological approaches) points of view. Our results revealed that both cell populations displayed almost identical ultrastructural characteristics represented by abundant cellular organelles dispersed in the cytoplasm. Moreover, the presence of very occasionally occurring mature endothelial-specific Weibel–Palade bodies (WPBs) confirmed their endothelial lineage origin. The more advanced stage of their differentiation was also demonstrated by the relatively low nucleus/cytoplasm (N/C) ratios (0.41 ± 0.19 in PB-EPCs; 0.37 ± 0.25 in BM-EPCs). Between PB-EPCs and BM-EPCs, no differences in proportions of cells occupied by nucleus (28.13 ± 8.97 versus 25.10 ± 11.48%), mitochondria (3.71 ± 1.33 versus 4.23 ± 1.00%), and lipid droplets (0.65 ± 1.01 versus 0.36 ± 0.40%), as well as in estimations of the organelles surface densities were found. The data provide the first quantitative evaluation of the organelles of interest in PB-EPCs and BM-EPCs, and they can serve as a research framework for understanding cellular function.
Governing the Family through Parental Responsibilisation and Professionalisation: An Analysis of the State ‘Family Education’ Discourses in Contemporary China
Authors: Ying Yumjyi Ji
Published: March 2022

It is a global trend for nations to set forth various social policies to guide and regulate parents in their parenting practices as a form of family governance. In China, this trend is echoed by a number of ‘family education’ policies and guidelines. Drawing upon a critical discourse analysis of three family education documents, this article argues that the ideal Chinese parent is one with high suzhi who is responsible, rational and competent in science-based parenting knowledge and skills, conjoining closely with China’s nation-building agenda to produce high suzhi citizens who could contribute to the building of a strong nation. In reference to international scholarship, these discourses are understood as a form of family governance through parental responsibilisation and professionalisation. The article also calls for more empirical research to understand the implications of these official discourses for parenting and parent-child relations in diverse socio-economic and cultural contexts around China.
THE ROOTS OF RESPONSIBILITY
Authors: Hyman John
Published: March 2022

Under what circumstances can we hold someone responsible for what they do?
THE METAPHYSICS OF FARTS
Authors: Capra Bill
Published: March 2022

I consider the metaphysics of farts. I contrast the essential-bum-origin view with a phenomenological view, and I argue in favour of the latter.
COMMENT FOR THINK ON NATURALISM VERSUS THEISM
Authors: Watson Brenda
Published: March 2022

The search for common ground is hugely important and it depends on understanding in as fair a way as possible how words are being used by opponents in debate – in this case naturalism and theism.
Catholic Mobilizations in Twentieth-Century Mexico: From Pious Lynchings and Fascist Salutes to a “Catholic 1968,” Maoist Priests, and the Post-Cristero Apocalypse
Authors: Butler Matthew
Published: March 2022

This special issue, fruit of an American Historical Association panel on the entanglements of Catholicism and nationhood after Mexico's Cristero War (1926-29), offers five new histories that cumulatively give the lie to anything so monolithic as a twentieth-century “Catholic history.” As is well known, the Cristero War was a major armed confrontation between the Church and the postrevolutionary state and their respective bases, followed, as the story goes, by an uneasy truce and an enduring coexistence lasting for decades, to the 1950s and perhaps to the 1970s.
Concurrent evolution of seed dormancy and herbicide resistance in field populations of dominant weed species in Western Australian cropping systems
Authors: Maity Aniruddha , Lujan Rocha Roberto , Khalil Yaseen , Bagavathiannan Muthukumar , Ashworth Michael B. , Beckie Hugh J.
Published: March 2022

Herbicide resistance, documented in many economically damaging weed species, is a major threat to global crop production. The injudicious use of herbicides, often in the absence of diverse weed control strategies, poses an immense selection pressure on weed communities for resistance evolution and weed adaptive traits such as high seed dormancy. This study evaluates the interaction among developing herbicide resistance, seed size, and seed dormancy of ripgut brome (Bromus diandrus Roth), wild oat (Avena fatua L.), and hare barley [Hordeum leporinum Link; syn. Hordeum murinum L. ssp. leporinum (Link) Arcang.] collected from within intensively managed fields (in-crop) in comparison with populations in surrounding ruderal (non-crop disturbed) areas with no history of exposure to herbicides within the Western Australian grainbelt. Seed size of the three species varied by farming system (continuous cereal-intensive annual crops, diverse annual crops, pasture based) and habitat (in-crop, ruderal). Field populations of H. leporinum and B. diandrus tended to have greater seed size compared with ruderal populations. Larger seeds had significantly more dormancy in all three weed species. Field-collected populations that were exposed to herbicide applications for at least the past 5 yr exhibited significantly greater seed dormancy compared with their counterparts present in ruderal areas within the same geographic area. The association between increased seed dormancy and developing multiple herbicide resistance further complicates effective weed management.
The Mental Health of German Students During the COVID-19 Pandemic
Authors: Supke Max , Schulz Wolfgang
Published: March 2022

Abstract. Theoretical background: The COVID-19 pandemic has changed the daily lives of students completely. Studies indicated that psychology students may be less stressed during the pandemic than other students. This study compares psychology students and students from other disciplines regarding their mental health, alcohol consumption, and partnerships after the third wave of the COVID-19 pandemic. Methods: The study sample consisted of n = 127 psychology students and n = 579 students from other disciplines at the TU Braunschweig in Germany who participated in an online survey in June / July of 2021. To analyze the differences between the psychology students and students from other disciplines after the third wave, we calculated t-tests, Chi²-tests, and U-tests separately for female and male students. Results: Significantly fewer female psychology students were above the cut-off values for clinically relevant depressive symptoms (31.5 %; p  < .001, Cramer’s  V = .32) and anxiety symptoms (22.2 %; p < .001, Cramer’s V = .27) than other female students (depressive symptoms: 66.1 %; anxiety symptoms: 41.9 %). The small sample of male psychology students showed similar tendencies. While female psychology students rated their general health and life satisfaction higher than other female students, male psychology students were less concerned about their professional future than their respective counterparts. No differences were found concerning alcohol consumption and partnerships. Conclusion: We found indications that psychology students, especially female students, are less psychologically distressed after the third wave than students from other disciplines. Better mental health knowledge could be an explanation for this.
Potassic Volcanism Induced by Mantle Upwelling Through a Slab Window: Evidence From Shear Wave Splitting Analyses in Central Java
Authors: Kong Fansheng , Gao Stephen S. , Liu Kelly H. , Li Jiabiao
Published: March 2022

To delineate the mantle flow fields in the vicinity of a previously proposed slab window and the possible roles that they may play in the formation of potassic volcanism in Central Java, we conduct shear wave splitting analyses using both local S and teleseismic XKS waves (including SKS, SKKS, and PKS) recorded by 121 onshore stations and two ocean bottom seismometers (OBSs). The XKS fast orientations from the OBSs are trench normal and in accord with previous subslab anisotropy measurements. In the eastern part of Central Java, the XKS and local S fast orientations from the onshore stations are mostly trench‐parallel; in contrast, in the western part of Central Java, the XKS fast orientations are trench‐normal while the local S measurements are spatially varying. The observations can be attributed to four flow systems including (a) subslab trench normal mantle flow in areas away from the trench which is entrained by the Australian Plate, (b) trench normal flow that goes into the mantle wedge from the subslab area through a slab window beneath the western part of the study area, (c) trench‐parallel subslab flow near the trench beneath the eastern part of the study area which is driven by slab‐rollback, and (d) dominantly trench‐parallel flow system in the mantle wedge reflecting the horizontal component of the escaped flow system through the slab window. We propose that the vertical component of the escaped flow is responsible for the formation of the potassic volcanoes in the adjacent oceanic area.
The Global Atmosphere‐aerosol Model ICON‐A‐HAM2.3–Initial Model Evaluation and Effects of Radiation Balance Tuning on Aerosol Optical Thickness
Authors: Salzmann M. , Ferrachat S. , Tully C. , Münch S. , Watson‐Parris D. , Neubauer D. , Siegenthaler‐Le Drian C. , Rast S. , Heinold B. , Crueger T. , Brokopf R. , Mülmenstädt J. , Quaas J. , Wan H. , Zhang K. , Lohmann U. , Stier P. , Tegen I.
Published: March 2022

The Hamburg Aerosol Module version 2.3 (HAM2.3) from the ECHAM6.3‐HAM2.3 global atmosphere‐aerosol model is coupled to the recently developed icosahedral nonhydrostatic ICON‐A (icon‐aes‐1.3.00) global atmosphere model to yield the new ICON‐A‐HAM2.3 atmosphere‐aerosol model. The ICON‐A and ECHAM6.3 host models use different dynamical cores, parameterizations of vertical mixing due to sub‐grid scale turbulence, and parameter settings for radiation balance tuning. Here, we study the role of the different host models for simulated aerosol optical thickness (AOT) and evaluate impacts of using HAM2.3 and the ECHAM6‐HAM2.3 two‐moment cloud microphysics scheme on several meteorological variables. Sensitivity runs show that a positive AOT bias over the subtropical oceans is remedied in ICON‐A‐HAM2.3 because of a different default setting of a parameter in the moist convection parameterization of the host models. The global mean AOT is biased low compared to MODIS satellite instrument retrievals in ICON‐A‐HAM2.3 and ECHAM6.3‐HAM2.3, but the bias is larger in ICON‐A‐HAM2.3 because negative AOT biases over the Amazon, the African rain forest, and the northern Indian Ocean are no longer compensated by high biases over the sub‐tropical oceans. ICON‐A‐HAM2.3 shows a moderate improvement with respect to AOT observations at AERONET sites. A multivariable bias score combining biases of several meteorological variables into a single number is larger in ICON‐A‐HAM2.3 compared to standard ICON‐A and standard ECHAM6.3. In the tropics, this multivariable bias is of similar magnitude in ICON‐A‐HAM2.3 and in ECHAM6.3‐HAM2.3. In the extra‐tropics, a smaller multivariable bias is found for ICON‐A‐HAM2.3 than for ECHAM6.3‐HAM2.3.
Using Ensemble Data Assimilation to Estimate Transient Hydrologic Exchange Flow Under Highly Dynamic Flow Conditions
Authors: Chen Kewei , Chen Xingyuan , Song Xuehang , Briggs Martin A. , Jiang Peishi , Shuai Pin , Hammond Glenn , Zhan Hongbin , Zachara John M.
Published: March 2022

Quantifying dynamic hydrologic exchange flows (HEFs) within river corridors that experience high‐frequency flow variations caused by dam regulations is important for understanding the biogeochemical processes at the river water and groundwater interfaces. Heat has been widely used as a tracer to infer steady‐state flow velocities through analytical solutions of heat transport defined by the diurnal temperature signals. Under sub‐daily dynamic flow conditions, however, such analytical solutions are not applicable due to the violation of their fundamental assumptions. In this study, we developed a data assimilation‐based approach to estimate the sub‐daily flux under highly dynamic flow conditions using multi‐depth temperature observations at a 5‐min resolution. If the hydraulic gradient is measured, Darcy's law was used to calculate the flux with permeability estimated from temperature responses below the riverbed. Otherwise, flux was estimated directly by assimilating multi‐depth temperature data at 1‐ or 2‐hr time intervals assuming one‐dimensional flow and heat transport governing equation. By comparing estimated fluxes with model‐generated synthetic truth, we demonstrated that both schemes have robust performance in estimating fluxes under highly dynamic flow conditions. This data assimilation‐based flux estimation method was able to capture the vertical sub‐daily fluxes using multi‐depth high‐resolution temperature data alone, even in the presence of multi‐dimensional flow. This approach has been successfully applied to real field temperature data collected at the Hanford site, which experiences highly dynamic HEFs. Our study shows the promise of adopting distributed 1‐D temperature monitoring to capture spatial and temporal exchange dynamics in river corridors at a watershed scale or beyond.
Satellites Help Cement South Africa’s Space Industry
Authors: Makoni Munyaradzi
Published: March 2022

A trio of CubeSats allows South Africa to showcase its growing space industry as well as monitor its coastal zones.
Once Extreme Ocean Temperatures Are the New Normal
Authors: Vasquez Krystal
Published: March 2022

A new analysis finds extreme warming events in the ocean have increased relative to the very far past, with nearly 60% of the ocean experiencing extreme heat in 2019.
Ab initio studies of magnetism and topology in solid Pd-rich $${\varvec{a}}$$-PdSi alloys
Authors: Rodríguez Isaías , Valladares Renela M. , Valladares Alexander , Hinojosa-Romero David , Valladares Ariel A.
Published: March 2022

In 1965 Duwez et al. reported having generated an amorphous, stable phase of palladium-silicon in the region 15 to 23 atomic percent, at.%, silicon. These pioneering efforts have led to the development of solid materials that are now known as Bulk Metallic Glasses, BMG. In 2019 Rodríguez et al. discovered, computationally, that bulk amorphous Pd becomes magnetic, and so does porous/amorphous Pd. Puzzled by these results, the study of several solid binary systems in the Pd-rich zone was undertaken; in particular, the study of the glassy metallic alloy a-Pd$$_{100-c}$$

100
-
c

Si$$_{c}$$

c

, for $$0 \le c \le 22$$

0
≤
c
≤
22

, (c in at.%) to see what their topology is, what their electronic properties are and to inquire about their magnetism. In this work it is shown that this metallic glass is in fact magnetic in the region $$0 \le c < 15$$

0
≤
c
<
15

. Collaterally $$\alpha$$
α
and $$\beta$$
β
magnetization curves are shown where the net magnetic moment is presented. The topology and the position of the first few peaks of the pair distribution functions, which agrees well with experiment, are also discussed. The BMGs produced experimentally so far are limited in size, but despite this limitation, recent industrial efforts have developed some useful devices that may revolutionize technology.
THz-photonics transceivers by all-dielectric phonon-polariton nonlinear nanoantennas
Authors: Leon Unai Arregui , Rocco Davide , Carletti Luca , Peccianti Marco , Maci Stefano , Della Valle Giuseppe , De Angelis Costantino
Published: March 2022

The THz spectrum (spanning from 0.3 to 30 THz) offers the potential of a plethora of applications, ranging from the imaging through non transparent media to wireless-over-fiber communications and THz-photonics. The latter framework would greatly benefit from the development of optical-to-THz wavelength converters. Exploiting Difference Frequency Generation in a nonlinear all dielectric nanoantenna, we propose a compact solution to this problem. By means of a near-infrared pump beam (at $$\omega _1$$

ω
1

), the information signal in the optical domain (at $$\omega _2$$

ω
2

) is converted to the THz band (at $$\omega _3=\omega _2-\omega _1$$

ω
3

=

ω
2

-

ω
1

). The approach is completely transparent with respect to the modulation format, and can be easily integrated in a metasurface platform for simultaneous frequency and spatial moulding of THz beams.
Morphine-induced modulation of Nrf2-antioxidant response element signaling pathway in primary human brain microvascular endothelial cells
Authors: Reymond Sandrine , Vujić Tatjana , Schvartz Domitille , Sanchez Jean-Charles
Published: March 2022

Morphine is one of the most potent opioid analgesic used for pain treatment. Morphine action in the central nervous system requires crossing the blood–brain barrier. Due to the controversial relationship between morphine and oxidative stress, the potential pro- or antioxidant effects of morphine in the blood–brain barrier is important to be understood, as oxidative stress could cause its disruption and predispose to neurodegenerative diseases. However, investigation is scarce in human brain endothelial cells. Therefore, the present study evaluated the impact of morphine exposure at three different concentrations (1, 10 and 100 µM) for 24 h and 48 h on primary human brain microvascular endothelial cells. A quantitative data-independent acquisition mass spectrometry strategy was used to analyze proteome modulations. Almost 3000 proteins were quantified of which 217 were reported to be significantly regulated in at least one condition versus untreated control. Pathway enrichment analysis unveiled dysregulation of the Nrf2 pathway involved in oxidative stress response. Seahorse assay underlined mitochondria dysfunctions, which were supported by significant expression modulations of relevant mitochondrial proteins. In conclusion, our study revealed the dysregulation of the Nrf2 pathway and mitochondria dysfunctions after morphine exposure, highlighting a potential redox imbalance in human brain endothelial cells.
The nanocaterpillar's random walk: diffusion with ligand–receptor contacts
Authors: Marbach Sophie , Zheng Jeana Aojie , Holmes-Cerfon Miranda
Published: March 2022

An analytic formula, veried by simulations and experiments, to quantify the diffusion of ligand-receptor systems over a broad parameter range.
Spontaneously rotating clusters of active droplets
Authors: Hokmabad Babak Vajdi , Nishide Akinori , Ramesh Prashanth , Krüger Carsten , Maass Corinna C.
Published: March 2022

We investigate the aggregation of hexagonally ordered clusters and the spontaneous emergence of their rotating and rising states in sedimenting suspensions of self-propelling isotropic oil droplets.
Promoting effect of Zn in high-loading Zn/Ni-SiO2 catalysts for selective hydrogen evolution from methylcyclohexane
Authors: Alekseeva (Bykova) Maria V. , Gulyaeva Yuliya K. , Bulavchenko Olga A. , Saraev Andrey A. , Kremneva Anna M. , Stepanenko Sergey A. , Koskin Anton P. , Kaichev Vasily V. , Yakovlev Vadim A.
Published: March 2022

Promoting effects arising from the bimetallic Ni–Zn solid solutions ensure the high selectivity of Ni-SiO2 catalysts modified by Zn in the dehydrogenation of methylcyclohexane.
Phase-transfer catalyzed Michael/ammonolysis cascade reactions of enaminones and olefinic azlactones: a new approach to structurally diverse quinoline-2,5-diones
Authors: Chen Lin , Liang Wei
Published: March 2022

A Michael/ammonolysis cascade reaction of enaminones and olefinic azlactones via phase-transfer catalysis has been developed, which provides rapid access to a diverse set of quinoline-2,5-diones bearing a secondary amide group at the C-3 position.
A photoelectrochemical sensor based on β‐cyclodextrin‐modified MoS2 quantum dots‐WS2 nanosheet composites for the detection of benzo [a]pyrene
Authors: Shi Jian‐Jun , Wang Zhe , Wang Yan , Shu Rui‐Wen , Yang Ping
Published: March 2022

A photoelectrochemical sensor has been developed for the detection of the polycyclic aromatic hydrocarbon pollutant benzo [a]pyrene (BaP). An n‐butyl lithium intercalation stripping method is applied to prepare tungsten disulphide nanosheets (WS2 NSs). WS2 NSs and β‐cyclodextrin (β‐CD)‐modified MoS2 quantum dots (QDs) are then compounded by hydrogen bonding between the amino and hydroxyl groups. After assembly on an indium tin oxide electrode, the energy level matching and synergistic photoelectric effect between β‐CD‐MoS2 QDs and WS2 NSs reduced the combination of photogenerated electrons and holes and an enhanced photocurrent signal is observed. As a result of the host–guest interaction between β‐CD and BaP, BaP could bind to the β‐CD‐MoS2 QDs in the nanocomposites, which hinders the electron migration to the electrode and weakened the photocurrent signal. Thus, the trace detection of BaP is realized. The rate of photocurrent change is also related to the BaP concentration from 1 to 20 nmol/L with a detection limit of 0.33 nmol/L. In summary, a highly sensitive and selective photoelectrochemical sensor for the detection of BaP is successfully constructed.
Using birefringent elements and imaging Michelsons for the calibration of high-precision planet-finding spectrographs
Authors: Schou J.
Published: March 2022

Context. One of the main methods used for finding extrasolar planets is the radial velocity technique, in which the Doppler shift of a star due to an orbiting planet is measured. These measurements are typically performed using cross-dispersed echelle spectrographs. Unfortunately, such spectrographs are large and expensive, and their accurate calibration continues to be challenging.

Aims. The aim is to develop a different way to provide a calibration signal.

Methods. A commonly used way to introduce a calibration signal is to insert an iodine cell in the beam. Disadvantages of this include that the lines are narrow, do not cover the entire spectrum, and light is absorbed. Here I show that inserting a birefringent element or an imaging Michelson, combined with Wollaston prisms, eliminates these three shortcomings while maintaining most of the benefits of the iodine approach.

Results. The proposed designs can be made very compact, thereby providing a convenient way of calibrating a spectrograph. Similar to the iodine cell approach, the calibration signal travels with the stellar signal, thereby reducing the sensitivity to spectrograph stability. The imposed signal covers the entire visible range, and any temperature drifts will be consistent and describable by a single number. Based on experience with similar devices that were used in a different configuration by the Helioseismic and Magnetic Imager, it is shown that the calibration device can be made stable at the 0.1 m/s level over a significant wavelength range on short to medium timescales.

Conclusions. While the design is promising, many details still need to be worked out. In particular, a number of laboratory measurements are required in order to finalize a design and estimate actual performance, and it would be desirable to make a proof of concept.
Exploring multiple generations of planetary embryos
Authors: Voelkel Oliver , Klahr Hubert , Mordasini Christoph , Emsenhuber Alexandre
Published: March 2022

Context. Global models of planet formation tend to begin with an initial set of planetary embryos for the sake of simplicity. While this approach gives valuable insights into the evolution of the initial embryos, the initial distribution itself is staked on a bold assumption. Limiting the study to an initial distribution may neglect essential physics that either precedes or follows such an initial distribution.

Aims. We wish to investigate the effect of dynamic planetary embryo formation on the formation of planetary systems.

Methods. The presented framework begins with an initial disk of gas, dust, and pebbles. The disk evolution, the formation of plan-etesimals and the formation of planetary embryos is modeled consistently. Embryos then grow by pebble accretion, followed by planetesimal and, eventually, gas accretion. Planet-disk interactions and N-body dynamics, along with a consideration of other simultaneously growing embryos, are included in the framework.

Results. We show that the formation of planets can occur in multiple consecutive phases. Earlier generations grow massive by pebble accretion but are subject to fast type I migration and, thus, by accretion to the star. The later generations of embryos that form grow too much smaller masses by planetesimal accretion, as the amount of pebbles in the disk has vanished.

Conclusions. The formation history of planetary systems may be far more complex than an initial distribution of embryos could reflect. The dynamic formation of planetary embryos needs to be considered in global models of planet formation to allow for a complete picture of the system’s evolution.
A probabilistic method for detecting solar-like oscillations using meaningful prior information
Authors: Nielsen M. B. , Hatt E. , Chaplin W. J. , Ball W. H. , Davies G. R.
Published: March 2022

Context. Current and future space-based observatories such as the Transiting Exoplanet Survey Satellite (TESS) and PLATO are set to provide an enormous amount of new data on oscillating stars, and in particular stars that oscillate similar to the Sun. Solar-like oscillators constitute the majority of known oscillating stars and so automated analysis methods are becoming an ever increasing necessity to make as much use of these data as possible.

Aims. Here we aim to construct an algorithm that can automatically determine if a given time series of photometric measurements shows evidence of solar-like oscillations. The algorithm is aimed at analyzing data from the TESS mission and the future PLATO mission, and in particular stars in the main-sequence and subgiant evolutionary stages.

Methods. The algorithm first tests the range of observable frequencies in the power spectrum of a TESS light curve for an excess that is consistent with that expected from solar-like oscillations. In addition, the algorithm tests if a repeating pattern of oscillation frequencies is present in the time series, and whether it is consistent with the large separation seen in solar-like oscillators. Both methods use scaling relations and observations which were established and obtained during the CoRoT, Kepler, and K2 missions.

Results. Using a set of test data consisting of visually confirmed solar-like oscillators and nonoscillators observed by TESS, we find that the proposed algorithm can attain a 94.7% true positive (TP) rate and a 8.2% false positive (FP) rate at peak accuracy. However, by applying stricter selection criteria, the FP rate can be reduced to ≈ 2%, while retaining an 80% TP rate.
A new protonated molecule discovered in TMC-1: HCCNCH+
Authors: Agúndez M. , Cabezas C. , Marcelino N. , Fuentetaja R. , Tercero B. , de Vicente P. , Cernicharo J.
Published: March 2022

In recent years we have seen an important increase in the number of protonated molecules detected in cold dense clouds. Here we report the detection in TMC-1 of HCCNCH+, the protonated form of HCCNC, which is a metastable isomer of HC3N. This is the first protonated form of a metastable isomer detected in a cold dense cloud. The detection was based on observations carried out with the Yebes 40 m telescope and the 30 m telescope of the Institut de Radioastronomie Millimétrique (IRAM), which revealed four harmonically related lines. We derived a rotational constant B = 4664.431891 ± 0.000692 MHz and a centrifugal distortion constant D = 519.14 ± 4.14 Hz. From a high level ab initio screening of potential carriers, we confidently assigned the series of lines to the ion HCCNCH+. We derived a column density of (3.0 ± 0.5) × 1010 cm−2 for HCCNCH+, which results in a HCCNCH+/HCCNC abundance ratio of 0.010 ± 0.002. This value is well reproduced by a state-of-the-art chemical model which, however, is subject to important uncertainties regarding the chemistry of HCCNCH+. The observational and theoretical status of protonated molecules in cold dense clouds indicate that there exists a global trend in which protonated-to-neutral abundance ratios MH+/M increase with increasing proton affinity of the neutral M, although if one is restricted to species M with high proton affinities (> 700 kJ mol−1), MH+/M ratios fall in the range 10−3–10−1, with no apparent correlation with the proton affinity. We suggest various protonated molecules that are good candidates for detection in cold dense clouds in the near future.
The effects of Pt doping on the optical properties of Au20
Authors: Jones Robert M. , D’Agosta Roberto , Baletto Francesca
Published: March 2022

We consider the doping of Pt onto small Au20 clusters, identifying the effects that this alloying has upon the optical and static properties of each candidate nanoalloy. By performing real-time time dependent density functional theory calculations, we determine that the electronic structure and, by extension, the optical absorption spectrum strongly depend on the position of a Pt dopant; either as substitutional defect, or as an adsorbed atom on the Au-surface. Indeed, we find that by varying the local positions, we are able to strongly influence the electronic and optical properties of complex nanoalloys. Of particular interest is the profound impact on the HOMO–LUMO gap of Au20 – shrinking or growing depending on the location of a Pt doping. By considering different possible locations and morphologies for the introduced Pt, we identify alloying types which may have a greater probability of supporting collective plasma oscillations.
Morphological Representation of C1q in the Aging Central Nervous
System
Authors: Rupprecht Christian , Sarker Rim S. J. , Rammes Gerhard
Published: March 2022

Introduction The complement protein C1q is essential for the innate immune
system and neurophysiological and neuropathological processes. To gain more
insight into these functions in the CNS, a comprehensive understanding of the
morphological representation, especially of its cellular and subcellular target
structures, is of great importance.

Methods For a free-floating preparation, the brains of wild-type and
ArcAβ mice were cut into 100 μm slices. Living slices were
incubated in Ringer’s solution and then fixed in 4%
paraformaldehyde (PFA) and stained with different primary and secondary
antibodies or methoxy-X04.

Results C1q was abundant in the entire brain. Interestingly, C1q
accumulated around cell nuclei, with a perineuronal localization around neuronal
somata and a paraneuronal accumulation around non-neuronal cells, e. g.,
microglia. Moreover, dendritic-like, linear, branched C1q signals were observed
in the area between the dentate gyrus and the CA1 region of the hippocampus.
Complementary staining revealed an overlap with β-amyloid accumulation
reflected by the deposition of C1q within plaques and modified basal C1q levels
in the brains of transgenic ArcAβ animals.

Discussion The applied free-floating approach is suitable for C1q
immunofluorescence imaging. The consistent colocalization of the complement
protein C1q with β-amyloid plaques may reflect an activated immune
response, whereas the accumulation of C1q around neuronal structures such as
somata and dendrites is still a matter of debate. Intriguingly, C1q surrounds
those structures in older brains of both wild-type and ArcAβ mice. Our
results also indicate an involvement of C1q in neurophysiological and
neurodegenerative processes.