bluuebunny/crossref_metadata_2025 huggingface dataset:
ExoPlaSim: Extending the Planet Simulator for exoplanets
Authors: Paradise Adiv , Macdonald Evelyn , Menou Kristen , Lee Christopher , Fan Bo Lin
Published: January 2022

The discovery of a large number of terrestrial exoplanets in the habitable zones of their stars, many of which are qualitatively different from Earth, has led to a growing need for fast and flexible 3D climate models, which could model such planets and explore multiple possible climate states and surface conditions. We respond to that need by creating ExoPlaSim, a modified version of the Planet Simulator (PlaSim) that is designed to be applicable to synchronously rotating terrestrial planets, planets orbiting stars with non-solar spectra, and planets with non-Earth-like surface pressures. In this paper, we describe our modifications, present validation tests of ExoPlaSim’s performance against other GCMs, and demonstrate its utility by performing two simple experiments involving hundreds of models. We find that ExoPlaSim agrees qualitatively with more-sophisticated GCMs such as ExoCAM, LMDG, and ROCKE-3D, falling within the ensemble distribution on multiple measures. The model is fast enough that it enables large parameter surveys with hundreds to thousands of models, potentially enabling the efficient use of a 3D climate model in retrievals of future exoplanet observations. We describe our efforts to make ExoPlaSim accessible to non-modellers, including observers, non-computational theorists, students, and educators through a new Python API and streamlined installation through pip, along with online documentation.
High-precision star formation efficiency measurements in nearby clouds
Authors: Hu Zipeng , Krumholz Mark R , Pokhrel Riwaj , Gutermuth Robert A
Published: January 2022

On average molecular clouds convert only a small fraction εff of their mass into stars per free-fall time, but different star formation theories make contrasting claims for how this low mean efficiency is achieved. To test these theories, we need precise measurements of both the mean value and the scatter of εff, but high-precision measurements have been difficult because they require determining cloud volume densities, from which we can calculate free-fall times. Until recently, most density estimates treated clouds as uniform spheres, while their real structures are often filamentary and highly non-uniform, yielding systematic errors in εff estimates and smearing real cloud-to-cloud variations. We recently developed a theoretical model to reduce this error by using column density distributions in clouds to produce more accurate volume density estimates. In this work, we apply this model to recent observations of 12 nearby molecular clouds. Compared to earlier analyses, our method reduces the typical dispersion of εff within individual clouds from 0.16 dex to 0.12 dex, and decreases the median value of εff over all clouds from ≈0.02 to ≈0.01. However, we find no significant change in the ≈0.2 dex cloud-to-cloud dispersion of εff, suggesting the measured dispersions reflect real structural differences between clouds.
Probing the initial mass function of the first stars with transients
Authors: Lazar Alexandres , Bromm Volker
Published: January 2022

The emergence of the first, so-called Population III (Pop III), stars shaped early cosmic history in ways that crucially depends on their initial mass function (IMF). However, because of the absence of direct observational constraints, the detailed IMF remains elusive. Nevertheless, numerical simulations agree in broad terms that the first stars were typically massive and should often end their lives in violent, explosive deaths. These fates include extremely luminous pair-instability supernovae (PISNe) and bright gamma-ray bursts (GRBs), the latter arising from the collapse of rapidly rotating progenitor stars into black holes. These high-redshift transients are expected to be within the detection limits of upcoming space telescope missions, allowing to place effective constraints on the shape of the primordial IMF that is not easily accessible with other probes. This paper presents a framework to probe the Pop III IMF, utilizing the cosmological source densities of high-redshift PISNe and GRBs. Considering these transients separately could provide useful constraints on the Pop III IMF, but tighter bounds are obtainable by combining PISN and GRB counts. This combined diagnostic is more robust as it is independent of the underlying Pop III star formation rate density, an unknown prior. Future surveys promise to capture most high-redshift GRBs across the entire sky, but high-redshift PISN searches with future telescopes, e.g. Roman Space Telescope, will likely be substantially incomplete. Nevertheless, we demonstrate that even such lower bounds on the PISN count will be able to provide key constraints on the primordial IMF, in particular, if it is top-heavy or not.
SN 2020kyg and the rates of faint Iax supernovae from ATLAS
Authors: Srivastav Shubham , Smartt S J , Huber M E , Chambers K C , Angus C R , Chen T-W , Callan F P , Gillanders J H , McBrien O R , Sim S A , Fulton M , Hjorth J , Smith K W , Young D R , Auchettl K , Anderson J P , Pignata G , de Boer T J L , Lin C-C , Magnier E A
Published: January 2022

We present multiwavelength follow-up observations of the ATLAS discovered faint Iax supernova SN 2020kyg that peaked at an absolute magnitude of Mg ≈ −14.9 ± 0.2, making it another member of the faint Iax supernova population. The bolometric light curve requires only ≈7 × 10−3 M⊙ of radioactive 56Ni, with an ejected mass of Mej ∼ 0.4 M⊙ and a low kinetic energy of E ≈ 0.05 ± 0.02 × 1051 erg. We construct a homogeneous volume-limited sample of 902 transients observed by ATLAS within 100 Mpc during a 3.5 yr span. Using this sample, we constrain the rates of faint Iax (Mr ≳ −16) events within 60 Mpc at $12^{+14}_{-8}{{\ \rm per\ cent}}$ of the SN Ia rate. The overall Iax rate, at $15^{+17}_{-9}{{\ \rm per\ cent}}$ of the Ia rate, is dominated by the low-luminosity events, with luminous SNe Iax (Mr ≲ −17.5) like 2002cx and 2005hk, accounting for only $0.9^{+1.1}_{-0.5}{{\ \rm per\ cent}}$ of the Ia rate (a 2σ upper limit of approximately 3 per cent). We favour the hybrid CONe WD + He star progenitor channel involving a failed deflagration of a near Chandrasekhar mass white dwarf, expected to leave a bound remnant and a surviving secondary companion, as a candidate explanation for faint Iax explosions. This scenario requires short delay times, consistent with the observed environments of SNe Iax. Furthermore, binary population synthesis calculations have suggested rates of $1\!-\!18{{\ \rm per\ cent}}$ of the SN Ia rate for this channel, consistent with our rate estimates.
Dynamics of intermediate-mass black holes wandering in the milky way galaxy using the illustris TNG50 simulation
Authors: Weller Emma Jane , Pacucci Fabio , Hernquist Lars , Bose Sownak
Published: January 2022

The detection of Intermediate-Mass Black Holes (IMBHs) in dwarf galaxies is crucial to closing the gap in the wide mass distribution of black holes ($\sim 3 \, {\rm M_\odot }$ to $\sim 5 \times 10^{10} \, {\rm M_\odot }$). IMBHs originally located at the centre of dwarfs that later collide with the Milky Way (MW) could be wandering, undetected, in our Galaxy. We used TNG50, the highest resolution run of the IllustrisTNG project, to study the kinematics and dynamics of star clusters, in the appropriate mass range, acting as IMBH proxies in an MW analogue galaxy. We showed that $\sim 87{{\ \rm per\ cent}}$ of our studied IMBHs drift inward. The radial velocity of these sinking IMBHs has a median magnitude of $\sim 0.44 \, \mathrm{ckpc \, h^{-1} \, Gyr^{-1}}$ and no dependence on the black hole mass. The central $1 \, \rm ckpc \, h^{-1}$ has the highest number density of IMBHs in the galaxy. A physical toy model with linear drag forces was developed to explain the orbital circularization with time. These findings constrain the spatial distribution of IMBHs, suggesting that future searches should focus on the central regions of the Galaxy. Additionally, we found that the 3D velocity distribution of IMBHs with respect to the galactic centre has a mean of $\sim 180 \, \mathrm{km \, s^{-1}}$ and larger variance with decreasing radius. Remarkably, the velocity distribution relative to the local gas shows significantly lower values, with a mean of $\sim 88 \, \mathrm{km \, s^{-1}}$. These results are instrumental for predicting the accretion and radiation properties of IMBHs, facilitating their detection with future surveys.
The puzzling story of flare inactive ultra fast rotating M dwarfs. II. Searching for radial velocity variations
Authors: Ramsay Gavin , Hakala Pasi , Doyle J Gerry , Doyle Lauren , Bagnulo Stefano
Published: January 2022

Observations made using TESS revealed a sample of low-mass stars which show a periodic modulation on a period <0.2 d. Surprisingly, many of these ultra fast rotating (UFR) stars showed no evidence of flare activity which would be expected from such rapidly rotating stars. We present results from a spectroscopic survey of UFRs using the Nordic Optical Telescope to search for radial velocity variations which could reveal evidence for binarity. Our sample of 29 sources have a photometric period between 0.1–0.2 d, cover spectral classes of M0-4V, and show no evidence for flares. We detect only one source with clear radial velocity shifts, with another two having Gaia RUWE values which suggests they are binaries. Further observations reveal the former star possibly contains a brown dwarf companion with a mass of M2 > 58 MJup and probability P(M2 < 90 MJup) = 50 per cent. There is no evidence for the companion in our spectra, strengthening the case for a brown dwarf companion. We also examine the folded TESS light curves of all our targets, finding at least two are eclipsing binaries and one which has been contaminated by a spatially nearby δ Sct star. We estimate that around 1/4 of our targets may have been contaminated by short period variable stars. However, the majority of our targets are consistent with being single, low mass stars whose variability is due to starspots. We outline the possible reasons why they are not flare active despite being such rapid rotators.
Mysterious odd radio circle near the large magellanic cloud – an intergalactic supernova remnant?
Authors: Filipović Miroslav D , Payne J L , Alsaberi R Z E , Norris R P , Macgregor P J , Rudnick L , Koribalski B S , Leahy D , Ducci L , Kothes R , Andernach H , Barnes L , Bojičić I S , Bozzetto L M , Brose R , Collier J D , Crawford E J , Crocker R M , Dai S , Galvin T J , Haberl F , Heber U , Hill T , Hopkins A M , Hurley-Walker N , Ingallinera A , Jarrett T , Kavanagh P J , Lenc E , Luken K J , Mackey D , Manojlović P , Maggi P , Maitra C , Pennock C M , Points S , Riggi S , Rowell G , Safi-Harb S , Sano H , Sasaki M , Shabala S , Stevens J , van Loon J Th , Tothill N F H , Umana G , Urošević D , Velović V , Vernstrom T , West J L , Wan Z
Published: January 2022

We report the discovery of J0624–6948, a low-surface brightness radio ring, lying between the Galactic Plane and the large magellanic cloud (LMC). It was first detected at 888 MHz with the Australian Square Kilometre Array Pathfinder (ASKAP), and with a diameter of ∼196 arcsec. This source has phenomenological similarities to odd radio circles (ORCs). Significant differences to the known ORCs – a flatter radio spectral index, the lack of a prominent central galaxy as a possible host, and larger apparent size – suggest that J0624–6948 may be a different type of object. We argue that the most plausible explanation for J0624–6948 is an intergalactic supernova remnant due to a star that resided in the LMC outskirts that had undergone a single-degenerate type Ia supernova, and we are seeing its remnant expand into a rarefied, intergalactic environment. We also examine if a massive star or a white dwarf binary ejected from either galaxy could be the supernova progenitor. Finally, we consider several other hypotheses for the nature of the object, including the jets of an active galactic nucleus (30Dor) or the remnant of a nearby stellar super-flare.
Quantifying uncertainty in deep learning approaches to radio galaxy classification
Authors: Mohan Devina , Scaife Anna M M , Porter Fiona , Walmsley Mike , Bowles Micah
Published: January 2022

In this work we use variational inference to quantify the degree of uncertainty in deep learning model predictions of radio galaxy classification. We show that the level of model posterior variance for individual test samples is correlated with human uncertainty when labelling radio galaxies. We explore the model performance and uncertainty calibration for different weight priors and suggest that a sparse prior produces more well-calibrated uncertainty estimates. Using the posterior distributions for individual weights, we demonstrate that we can prune 30 per cent of the fully connected layer weights without significant loss of performance by removing the weights with the lowest signal-to-noise ratio. A larger degree of pruning can be achieved using a Fisher information based ranking, but both pruning methods affect the uncertainty calibration for Fanaroff–Riley type I and type II radio galaxies differently. Like other work in this field, we experience a cold posterior effect, whereby the posterior must be down-weighted to achieve good predictive performance. We examine whether adapting the cost function to accommodate model misspecification can compensate for this effect, but find that it does not make a significant difference. We also examine the effect of principled data augmentation and find that this improves upon the baseline but also does not compensate for the observed effect. We interpret this as the cold posterior effect being due to the overly effective curation of our training sample leading to likelihood misspecification, and raise this as a potential issue for Bayesian deep learning approaches to radio galaxy classification in future.
Image feature extraction and galaxy classification: a novel and efficient approach with automated machine learning
Authors: Tarsitano F , Bruderer C , Schawinski K , Hartley W G
Published: January 2022

In this work, we explore the possibility of applying machine learning methods designed for 1D problems to the task of galaxy image classification. The algorithms used for image classification typically rely on multiple costly steps, such as the point spread function deconvolution and the training and application of complex Convolutional Neural Networks of thousands or even millions of parameters. In our approach, we extract features from the galaxy images by analysing the elliptical isophotes in their light distribution and collect the information in a sequence. The sequences obtained with this method present definite features allowing a direct distinction between galaxy types. Then, we train and classify the sequences with machine learning algorithms, designed through the platform Modulos AutoML. As a demonstration of this method, we use the second public release of the Dark Energy Survey (DES DR2). We show that we are able to successfully distinguish between early-type and late-type galaxies, for images with signal-to-noise ratio greater than 300. This yields an accuracy of $86{{\ \rm per\ cent}}$ for the early-type galaxies and $93{{\ \rm per\ cent}}$ for the late-type galaxies, which is on par with most contemporary automated image classification approaches. The data dimensionality reduction of our novel method implies a significant lowering in computational cost of classification. In the perspective of future data sets obtained with e.g. Euclid and the Vera Rubin Observatory, this work represents a path towards using a well-tested and widely used platform from industry in efficiently tackling galaxy classification problems at the peta-byte scale.
A GALAH view of the chemical homogeneity and ages of stellar strings identified in Gaia
Authors: Manea Catherine , Hawkins Keith , Maas Zachary G
Published: January 2022

The advent of Gaia has led to the discovery of nearly 300 elongated stellar associations (called ‘strings’) spanning hundreds of parsecs in length and mere tens of parsecs in width. These newfound populations present an excellent laboratory for studying the assembly process of the Milky Way thin disc. In this work, we use data from GALAH DR3 to investigate the chemical distributions and ages of 18 newfound stellar populations, 10 of which are strings and 8 of which are compact in morphology. We estimate the intrinsic abundance dispersions in [X/H] of each population and compare them with those of both their local fields and the open cluster (OC) M 67. We find that all but one of these groups are more chemically homogeneous than their local fields. Furthermore, half of the strings, namely Theias 139, 169, 216, 303, and 309, have intrinsic [X/H] dispersions that range between 0.01 and 0.07 dex in most elements, equivalent to those of many OCs. These results provide important new observational constraints on star formation and the chemical homogeneity of the local interstellar medium (ISM). We investigate each population’s Li and chemical clock abundances (e.g. [Sc/Ba], [Ca/Ba], [Ti/Ba], and [Mg/Y]) and find that the ages suggested by chemistry generally support the isochronal ages in all but six structures. This work highlights the unique advantages that chemistry holds in the study of kinematically related stellar groups.
matryoshka: halo model emulator for the galaxy power spectrum
Authors: Donald-McCann Jamie , Beutler Florian , Koyama Kazuya , Karamanis Minas
Published: January 2022

We present matryoshka, a suite of neural-network-based emulators and accompanying python package that have been developed with the goal of producing fast and accurate predictions of the non-linear galaxy power spectrum. The suite of emulators consists of four linear component emulators, from which fast linear predictions of the power spectrum can be made, allowing all non-linearities to be included in predictions from a non-linear boost component emulator. The linear component emulators include an emulator for the matter transfer function that produces predictions in ∼0.0004 s, with an error of ${\lt} 0.08{{\ \rm per\ cent}}$ (at 1σ level) on scales 10−4 < k < 101 h Mpc−1. In this paper, we demonstrate matryoshka by training the non-linear boost component emulator with analytic training data calculated with Halofit, which has been designed to replicate training data that would be generated using numerical simulations. Combining all the component emulator predictions we achieve an accuracy of ${\lt} 0.75{{\ \rm per\ cent}}$ (at 1σ level) when predicting the real space non-linear galaxy power spectrum on scales 0.0025 < k < 1 h Mpc−1. We use matryoshka to investigate the impact of the analysis set-up on cosmological constraints by conducting several full shape analyses of the real-space galaxy power spectrum. Specifically we investigate the impact of the minimum scale (or kmax), finding an improvement of ∼1.8× in the constraint on σ8 by pushing kmax from 0.25 to 0.85 h Mpc−1, highlighting the potential gains when using clustering emulators such as matryoshka in cosmological analyses.
Metallicity distribution of the progenitor of the Giant Stellar Stream in the Andromeda Galaxy
Authors: Milošević S , Mićić M , Lewis G F
Published: January 2022

The Giant Stellar Stream (GSS) is a prominent tidal feature in the halo of the Andromeda galaxy (M31), representing the ongoing destruction of a satellite galaxy. In this paper, we investigate the formation of the GSS through detailed numerical simulations of the tidal disruption of a progenitor system. Assuming that the stream was created in a single merger event between M31 and a dwarf spheroidal galaxy with stellar mass $10^{9}\, {\rm M}_{\odot }$, we successfully reproduce the dynamical properties of the GSS. As the metallicity distribution along the stream has been well determined from observations (Pan-Andromeda Archaeological Survey and Absorption Maps in the Gas of Andromeda data sets), we use Monte Carlo simulations to reconstruct the original metallicity distribution of the dwarf progenitor. We find that a progenitor dwarf galaxy with a negative radial metallicity gradient, ΔFeH = −0.3 ± 0.2, reproduces the observed GSS properties at a time between 2.4 and 2.9 Gyr into the merger. We also show that the observed double-peak metallicity distribution along the stream is a transitory structure caused by unique merger circumstances where two groups of streaming stars are moving in opposite directions, intersecting to produce the peaks.
Filamentation of fast radio bursts in magnetar winds
Authors: Sobacchi Emanuele , Lyubarsky Yuri , Beloborodov Andrei M , Sironi Lorenzo
Published: January 2022

Magnetars are the most promising progenitors of fast radio bursts (FRBs). Strong radio waves propagating through the magnetar wind are subject to non-linear effects, including modulation/filamentation instabilities. We derive the dispersion relation for modulations of strong waves propagating in magnetically dominated pair plasmas focusing on dimensionless strength parameters a0 ≲ 1, and discuss implications for FRBs. As an effect of the instability, the FRB-radiation intensity develops sheets perpendicular to the direction of the wind magnetic field. When the FRB front expands outside the radius where the instability ends, the radiation sheets are scattered due to diffraction. The FRB-scattering time-scale depends on the properties of the magnetar wind. In a cold wind, the typical scattering time-scale is τsc ∼  $\mu$s–ms at the frequency $\nu \sim 1\, {\rm GHz}$. The scattering time-scale increases at low frequencies, with the scaling τsc ∝ ν−2. The frequency-dependent broadening of the brightest pulse of FRB 181112 is consistent with this scaling. From the scattering time-scale of the pulse, one can estimate that the wind Lorentz factor is larger than a few tens. In a warm wind, the scattering time-scale can approach $\tau _{\rm sc}\sim \, {\rm ns}$. Then scattering produces a frequency modulation of the observed intensity with a large bandwidth, $\Delta \nu \sim 1/\tau _{\rm sc}\gtrsim 100\, {\rm MHz}$. Broad-band frequency modulations observed in FRBs could be due to scattering in a warm magnetar wind.
Quasi-periodic spicule-like cool jets driven by Alfvén pulses
Authors: Singh B , Srivastava A K , Sharma K , Mishra S K , Dwivedi B N
Published: January 2022

We perform a 2.5D magnetohydrodynamic simulation to gain a comprehensive understanding of the formation of spicule-like cool jets caused by initial transverse velocity pulses akin to Alfvén pulses in the solar chromosphere. We invoke multiple velocity (Vz) pulses between 1.5 and 2.0 Mm in the solar atmosphere, which create the initial transverse velocity perturbations. These pulses transfer energy non-linearly to the field-aligned perturbations via the ponderomotive force. This physical process further creates magnetoacoustic shocks followed by quasi-periodic plasma motions in the solar atmosphere. The field-aligned magnetoacoustic shocks move upwards, which subsequently causes the quasi-periodic rise and fall of chromospheric plasma into the overlying corona as thin and cool spicule-like jets. The magnitude of the initial applied transverse velocity pulses is taken in the range of 50–90 km s−1. These pulses are found to be strong enough to generate spicule-like jets. We analyse the evolution, kinematics and energetics of these spicule-like jets. We find that the transported mass flux and kinetic energy density are substantial in the local solar corona. These mass motions generate in situ quasi-periodic oscillations on the scale of ≃ 4.0 min above the transition region.
Is Illicit Cigarette Market a Threat to Tobacco Control in Ethiopia?
Authors: Dauchy Estelle , Ross Hana
Published: January 2022

Introduction

The presence of an illicit cigarette trade is used as an argument in Ethiopia to halt pro-health tobacco tax policies. The National Tobacco Enterprise (NTE) recently reported that the illicit cigarette market accounts for over 61% of the total market, and over 90% in the Eastern part of Ethiopia.

Aims and Methods

The aim of the study is to estimate the magnitude of the illicit cigarette trade in Ethiopia. We employed a cross-sectional observational study of empty packs collected in Ethiopia from retailers and from the streets in 10 towns, representing 10 regional states, and two autonomous cities.

Results

The majority (80.1%) of the 6438 empty cigarette packs collected (5368 from the streets and 1070 from retailers) belonged to locally produced brands, while the remaining 19.9% were foreign packs, including those allowed to trade in Ethiopia. Overall, 18.9% of the collected empty packs were classified as illicit. However, the share of illicit cigarette packs varied considerably across the country with as many as 97.7% of the packs collected near the Eastern border being illicit. Since the smoking prevalence is significantly higher in that part of Ethiopia, the weighted estimate of illicit cigarette market reached 45.4%.

Conclusions

To address this alarming situation, Ethiopia should adopt technologies such as a track and trace system to control its cigarette supply chain, because cigarette packs currently bear no indication that the proper tax was paid. In addition, law enforcement and border security need to be strengthened, especially in the East.

Implications

This is the first study to estimate the magnitude of the illicit cigarette trade in Ethiopia. It shows that the illicit cigarette trade is low in most parts of the country, but points to some problematic areas near the border with Somalia where illicit cigarette prevalence and overall smoking prevalence are high. We propose a solution to control illicit cigarette trade in Ethiopia that the whole region would benefit from.
Antibiotic Resistance Patterns and Association With the Influenza Season in the United States: A Multicenter Evaluation Reveals Surprising Associations Between Influenza Season and Resistance in Gram-Negative Pathogens
Authors: Gupta Vikas , Yu Kalvin C , Kabler Heidi , Watts Janet A , Amiche Amine
Published: January 2022

Background

Viral infections are often treated with empiric antibiotics due to suspected bacterial coinfections, leading to antibiotic overuse. We aimed to describe antibiotic resistance (ABR) trends and their association with the influenza season in ambulatory and inpatient settings in the United States.

Methods

We used the BD Insights Research Database to evaluate antibiotic susceptibility profiles in 30-day nonduplicate bacterial isolates collected from patients >17 years old at 257 US healthcare institutions from 2011 to 2019. We investigated ABR in Gram-positive (Staphylococcus aureus and Streptococcus pneumoniae) and Gram-negative (Enterobacterales [ENT], Pseudomonas aeruginosa [PSA], and Acinetobacter baumannii spp [ACB]) bacteria expressed as the proportion of isolates not susceptible ([NS], intermediate or resistant) and resistance per 100 admissions (inpatients only). Antibiotics included carbapenems (Carb), fluoroquinolones (FQ), macrolides, penicillin, extended-spectrum cephalosporins (ESC), and methicillin. Generalized estimating equations models were used to evaluate monthly trends in ABR outcomes and associations with community influenza rates.

Results

We identified 8 250 860 nonduplicate pathogens, including 154 841 Gram-negative Carb-NS, 1 502 796 Gram-negative FQ-NS, 498 012 methicillin-resistant S aureus (MRSA), and 44 131 NS S pneumoniae. All S pneumoniae rates per 100 admissions (macrolide-, penicillin-, and ESC-NS) were associated with influenza rates. Respiratory, but not nonrespiratory, MRSA was also associated with influenza. For Gram-negative pathogens, influenza rates were associated with the percentage of FQ-NS ENT, FQ-NS PSA, and Carb-NS ACB.

Conclusions

Our study showed expected increases in rates of ABR Gram-positive and identified small but surprising increases in ABR Gram-negative pathogens associated with influenza activity. These insights may help inform antimicrobial stewardship initiatives.
Efficient approaches for harvesting solar energy in cogeneration: a review
Authors: Yao Jian , Liu Wenjie , Jiang Yifan , Zheng Sihang , Zhao Yao , Dai Yanjun , Zhu Junjie , Novakovic Vojislav
Published: January 2022

Stronger urbanization will increase the demand for power and thermal energy to meet the new energy service requirements, which often leads to higher fossil fuels use and emissions. Renewable energy utilization has high potential in urban context to reduce carbon emissions. Solar energy in particular has proved to be promising renewable source due to its ubiquity, abundance and sustainability. Efficient utilization of solar energy for cogeneration is an important application in the built environment, with wide applicability. This review provides a comprehensive state-of-the-art analysis of solar energy for combined heat and power supply based on the available literature. Different approaches to solar cogeneration are classified and critically reviewed. The review shows that efficient solar cogeneration methods could significantly improve the utilization efficiency of solar energy.
High-Ultrahigh Temperature Metamorphism in the Larsemann Hills: Insights into the Tectono-Thermal Evolution of the Prydz Bay Region, East Antarctica
Authors: Wang Wei-(Rz) , Zhao Yue , Wei Chunjing , Daczko Nathan R , Liu Xiaochun , Xiao Wenjiao , Zhang Zhiyong
Published: January 2022

As one of the widest terranes exposed in icy Antarctica, the Larsemann Hills in the Prydz Bay belt preserves diverse rock types with a complex metamorphic history and thus is critical to the tectono-metamorphic evolution of East Antarctica. Garnet-sillimanite-spinel-cordierite–bearing and garnet-orthopyroxene–bearing granulites are typical rocks in the region. Phase equilibrium modelling and mineral thermometry based on detailed petrological and mineralogical analyses indicate that the granulites underwent extreme metamorphism with peak conditions to ultrahigh temperatures (UHTs). The high-UHT metamorphism is characterised by extremely high dT/dP values (>1000°C/GPa) along a clockwise path with evident decompression at high temperatures and subsequent near isobaric cooling. Textural relationships, in situ NanoSIMS zircon U–Pb analysis, and LA-ICP-MS zircon and monazite dating and trace element analysis indicate protracted tectono-thermal evolution from the latest Neoproterozoic to early Palaeozoic (c. 570–500 Ma), with a prograde stage likely from c. 570 to c. 550 Ma, a peak stage from c. 550 to c. 540 Ma, and a retrograde stage from c. 540 to c. 500 Ma. During the retrograde stage, major decompression should have occurred before c. 530 Ma, as indicated by the age of zircon included in spinel, and then near isobaric cooling followed and persisted from c. 530 to c. 500 Ma. The geochronological data contribute to the establishment of the thermal–temporal framework of the late Neoproterozoic to early Palaeozoic Prydz tectonic event. The results also indicate that the assemblage of the investigated granulites basically resulted from the late Neoproterozoic to the early Palaeozoic tectono-thermal event, and the high-UHT conditions revealed by the granulites in the Larsemann Hills imply a much wider distribution of high heat flow and potential UHT metamorphism in the Prydz Bay region. Both the Larsemann Hills and the Rauer Group may have been in a similar and interrelated tectono-thermal setting from the late Neoproterozoic to the early Palaeozoic during the assembly of the Gondwana supercontinent.
BRASSINOSTEROID-SIGNALING KINASE1 modulates MAP KINASE15 phosphorylation to confer powdery mildew resistance in Arabidopsis
Authors: Shi Hua , Li Qiuyi , Luo Mingyu , Yan Haojie , Xie Bao , Li Xiang , Zhong Guitao , Chen Desheng , Tang Dingzhong
Published: January 2022

Perception of pathogen-associated molecular patterns (PAMPs) by plant cell surface-localized pattern-recognition receptors (PRRs) triggers the first line of plant innate immunity. In Arabidopsis thaliana, the receptor-like cytoplasmic kinase BRASSINOSTEROID-SIGNALING KINASE1 (BSK1) physically associates with PRR FLAGELLIN SENSING2 and plays an important role in defense against multiple pathogens. However, how BSK1 transduces signals to activate downstream immune responses remains elusive. Previously, through whole-genome phosphorylation analysis using mass spectrometry, we showed that phosphorylation of the mitogen-activated protein kinase (MAPK) MPK15 was affected in the bsk1 mutant compared with the wild-type plants. Here, we demonstrated that MPK15 is important for powdery mildew fungal resistance. PAMPs and fungal pathogens significantly induced the phosphorylation of MPK15 Ser-511, a key phosphorylation site critical for the functions of MPK15 in powdery mildew resistance. BSK1 physically associates with MPK15 and is required for basal and pathogen-induced MPK15 Ser-511 phosphorylation, which contributes to BSK1-mediated fungal resistance. Taken together, our data identified MPK15 as a player in plant defense against powdery mildew fungi and showed that BSK1 promotes fungal resistance in part by enhancing MPK15 Ser-511 phosphorylation. These results uncovered a mechanism of BSK1-mediated disease resistance and provided new insight into the role of MAPK phosphorylation in plant immunity.
Maize Interveinal Chlorosis 1 links the Yang Cycle and Fe homeostasis through Nicotianamine biosynthesis
Authors: Sun Wentao , Zhou Xiaojin J , Chen Chen , Zhang Xin , Tian Xiaolong , Xiao Ke , Liu Chenxu , Chen Rumei , Chen Shaojiang
Published: January 2022

The Yang cycle is involved in many essential metabolic pathways in plant growth and development. As extended products of the Yang cycle, the function and regulation network of ethylene and polyamines are well characterized. Nicotianamine (NA) is also a product of this cycle and works as a key metal chelator for iron (Fe) homeostasis in plants. However, interactions between the Yang cycle and NA biosynthesis remain unclear. Here, we cloned maize interveinal chlorosis 1 (mic1), encoding a 5′-methylthioadenosine nucleosidase (MTN), that is essential for 5′-methylthioadenosine (MTA) salvage and NA biosynthesis in maize (Zea mays). A single base G–A transition in the fourth exon of mic1 causes a Gly to Asp change, resulting in increased MTA, reduced Fe distribution, and growth retardation of seedlings. Knockout of ZmMIC1 but not its paralog ZmMTN2 by CRISPR/Cas9 causes interveinal chlorosis, indicating ZmMIC1 is mainly responsible for MTN activity in maize. Transcriptome analysis showed a typical response of Fe deficiency. However, metabolic analysis revealed dramatically reduced NA content in mic1, suggesting NA biosynthesis was impaired in the mutant. Exogenous application of NA transiently reversed the interveinal chlorosis phenotype of mic1 seedlings. Moreover, the mic1 mutant overexpressing a NA synthase gene not only recovered from interveinal chlorosis and growth retardation but was also fertile. These findings provide a link between the Yang cycle and NA biosynthesis, which highlights an aspect of Fe homeostasis regulation in maize.
Sovereign Bonds Since Waterloo
Authors: Meyer Josefin , Reinhart Carmen M , Trebesch Christoph
Published: January 2022

This article studies external sovereign bonds as an asset class. We compile a new database of 266,000 monthly prices of foreign-currency government bonds traded in London and New York between 1815 (the Battle of Waterloo) and 2016, covering up to 91 countries. Our main insight is that, as in equity markets, the returns on external sovereign bonds have been sufficiently high to compensate for risk. Real ex post returns average more than 6% annually across two centuries, including default episodes, major wars, and global crises. This represents an excess return of 3%–4% above US or UK government bonds, which is comparable to stocks and outperforms corporate bonds. Central to this finding are the high average coupons offered on external sovereign bonds. The observed returns are hard to reconcile with canonical theoretical models and the degree of credit risk in this market, as measured by historical default and recovery rates. Based on our archive of more than 300 sovereign debt restructurings since 1815, we show that full repudiation is rare; the median creditor loss (haircut) is below 50%.
Banks, Political Capital, and Growth
Authors: Lambert Thomas , Wagner Wolf , Zhang Eden Quxian
Published: January 2022

We show that politically connected banks influence economic activity. We exploit shocks to individual banks’ political capital following close U.S. congressional elections. We find that regional output growth increases when banks active in the region experience an average positive shock to their political capital. The effect is economically large, but temporary, and is due to lower restructuring in the economy, not increased productivity. We show that eased lending conditions (especially for riskier firms) can account for the growth effect. Our analysis is a first attempt to directly link the politics and finance literature with the finance and growth literature. (JEL, D72, E65, G21, G28, O43, O51).

Authors have furnished an Internet Appendix, which is available on the Oxford University Press Web site next to the link to the final published paper online.
Modular-Level Functional Connectome Alterations in Individuals With Hallucinations Across the Psychosis Continuum
Authors: Schutte Maya J L , Voppel Alban , Collin Guusje , Abramovic Lucija , Boks Marco P M , Cahn Wiepke , van Haren Neeltje E M , Hugdahl Kenneth , Koops Sanne , Mandl René C W , Sommer Iris E C
Published: January 2022

Functional connectome alterations, including modular network organization, have been related to the experience of hallucinations. It remains to be determined whether individuals with hallucinations across the psychosis continuum exhibit similar alterations in modular brain network organization. This study assessed functional connectivity matrices of 465 individuals with and without hallucinations, including patients with schizophrenia and bipolar disorder, nonclinical individuals with hallucinations, and healthy controls. Modular brain network organization was examined at different scales of network resolution, including (1) global modularity measured as Qmax and Normalised Mutual Information (NMI) scores, and (2) within- and between-module connectivity. Global modular organization was not significantly altered across groups. However, alterations in within- and between-module connectivity were observed for higher-order cognitive (e.g., central-executive salience, memory, default mode), and sensory modules in patients with schizophrenia and nonclinical individuals with hallucinations relative to controls. Dissimilar patterns of altered within- and between-module connectivity were found bipolar disorder patients with hallucinations relative to controls, including the visual, default mode, and memory network, while connectivity patterns between visual, salience, and cognitive control modules were unaltered. Bipolar disorder patients without hallucinations did not show significant alterations relative to controls. This study provides evidence for alterations in the modular organization of the functional connectome in individuals prone to hallucinations, with schizophrenia patients and nonclinical individuals showing similar alterations in sensory and higher-order cognitive modules. Other higher-order cognitive modules were found to relate to hallucinations in bipolar disorder patients, suggesting differential neural mechanisms may underlie hallucinations across the psychosis continuum.
Politics as a Vacation: Tourist Practices and the Building of the Nation-State
Authors: Fayard Gregory
Published: January 2022

Recent shifts in political sociology have moved away from reification of the state to focus more on symbolic and everyday sociocultural perceptions of political units. Yet the launching points for most research has been state-led programs. To remedy this gap, this paper takes a relatively non-political activity, domestic tourism, and builds a theoretical model of how the circulation of tourist bodies provides legitimation for the material, symbolic, and territorial projects of the nation-state. Using qualitative content analysis of online travel diaries for domestic vacations taken in China from 2006–2019, I find that travel practices are integral to perceptions of and bodily engagement with the geography, history, ethno-culture, and modernization projects of the nation-state. I argue that tourist practices naturalize and confirm knowledge and classifications about the nation-state, making abstract political conceptions into experiential realities.
SynBio2Easy—a biologist-friendly tool for batch operations on SBOL designs with Excel inputs
Authors: Zieliński Tomasz , Hay Johnny , Romanowski Andrew , Nenninger Anja , McCormick Alistair , Millar Andrew J
Published: January 2022

Practical delivery of Findable, Accessible, Reusable and Interoperable principles for research data management requires expertise, time resource, (meta)data standards and formats, software tools and public repositories. The Synthetic Biology Open Language (SBOL2) metadata standard enables FAIR sharing of the designs of synthetic biology constructs, notably in the repository of the SynBioHub platform. Large libraries of such constructs are increasingly easy to produce in practice, for example, in DNA foundries. However, manual curation of the equivalent libraries of designs remains cumbersome for a typical lab researcher, creating a barrier to data sharing. Here, we present a simple tool SynBio2Easy, which streamlines and automates operations on multiple Synthetic Biology Open Language (SBOL) designs using Microsoft Excel® tables as metadata inputs. The tool provides several utilities for manipulation of SBOL documents and interaction with SynBioHub: for example, generation of a library of plasmids based on an original design template, bulk deposition into SynBioHub, or annotation of existing SBOL component definitions with notes and authorship information. The tool was used to generate and deposit a collection of 3661 cyanobacterium Synechocystis plasmids into the public SynBioHub repository. In the process of developing the software and uploading these data, we evaluated some aspects of the SynBioHub platform and SBOL ecosystem, and we discuss proposals for improvement that could benefit the user community. With software such as SynBio2Easy, we aim to deliver a user-driven tooling to make FAIR a reality at all stages of the project lifecycle in synthetic biology research.

Graphical Abstract
Anodal tDCS over the medial prefrontal cortex enhances behavioral adaptation after punishments during reversal learning through increased updating of unchosen choice options
Authors: Panitz Martin , Deserno Lorenz , Kaminski Elisabeth , Villringer Arno , Sehm Bernhard , Schlagenhauf Florian
Published: January 2022

The medial prefrontal cortex (mPFC) is thought to be central for flexible behavioral adaptation. However, the causal relationship between mPFC activity and this behavior is incompletely understood. We investigated whether transcranial direct current stimulation (tDCS) over the mPFC alters flexible behavioral adaptation during reward-based decision-making, targeting Montreal Neurological Institute (MNI) coordinates X = −8, Y = 62, Z = 12, which has previously been associated with impaired behavioral adaptation in alcohol-dependent patients. Healthy human participants (n = 61) received either anodal (n = 30) or cathodal (n = 31) tDCS versus sham tDCS while performing a reversal learning task. To assess the mechanisms of reinforcement learning (RL) underlying our behavioral observations, we applied computational models that varied with respect to the updating of the unchosen choice option. We observed that anodal stimulation over the mPFC induced increased choice switching after punishments compared with sham stimulation, whereas cathodal stimulation showed no effect on participants’ behavior compared with sham stimulation. RL revealed increased updating of the unchosen choice option under anodal as compared with sham stimulation, which accounted well for the increased tendency to switch after punishments. Our findings provide a potential model for tDCS interventions in conditions related to flexible behavioral adaptation, such as addiction.
Perfluorooctanoic Acid Disrupts Ovarian Steroidogenesis and Folliculogenesis in Adult Mice
Authors: Yang May , Lee Yuna , Gao Liying , Chiu Karen , Meling Daryl D , Flaws Jodi A , Warner Genoa R
Published: January 2022

Perfluorooctanoic acid (PFOA) is a synthetic fluorosurfactant used in the manufacturing of fluorotelomers. Although PFOA is no longer produced in the United States, it is environmentally persistent and found in imported food packaging, cookware, and textiles. Previous studies have identified developmental toxicity of PFOA, but little is known about the effects of PFOA on the adult ovary. Thus, this study examined the effects of PFOA on hormone levels, ovarian steroidogenic gene expression, and folliculogenesis in mice in vitro and in vivo. For the in vitro studies, antral follicles from adult female mice were cultured with vehicle control or 1, 10, or 100 μg/ml PFOA for 96 h. For the in vivo studies, adult CD-1 female mice were orally dosed with vehicle control or 1, 5, 10, or 20 mg/kg/day PFOA for 10 days. Gene expression of steroidogenic enzymes, levels of sex steroid hormones, and follicle counts were analyzed. In vitro, PFOA (100 μg/ml) significantly decreased follicle growth, estradiol and estrone levels, and gene expression of StaR, Cyp11a1, and Hsd3b1 compared with controls. In vivo, exposure to PFOA significantly decreased progesterone and pregnenolone levels (5 mg/kg), increased testosterone levels (1 mg/kg), and increased gene expression of Cyp19a1 (1 mg/kg) compared with controls. Exposure to PFOA also significantly altered follicle counts by decreasing primordial follicles and increasing preantral and antral follicles (5 and 10 mg/kg) compared with controls. Collectively, these data show that PFOA disrupts adult ovarian function in a nonmonotonic matter and may pose a risk for premature ovarian failure.
Conifer desiccation in the 2021 NW heatwave confirms the role of hydraulic damage
Authors: Klein Tamir , Torres-Ruiz Jose M , Albers John J
Published: January 2022

The unprecedented heatwave which hit the Pacific northwest of North America in late June–early July 2021 impacted ecosystems and communities, yet evidence for and analysis of this impact are still missing. Here we bring a unique dataset quantifying the impact on conifer trees, which are keystone species of many northwest ecosystems. Moreover, we take advantage of this exceptional event as a broad, extreme, ‘field experiment’ to test a fundamental theory in plant physiology and prepare our forests for a harsher future. Overall, the data collected confirm the role of hydraulic vulnerability in drought-induced injury to trees.
China's top 10 hematological advances in 2021 lists the key developments in hematology in China for that year
Authors: Wang Xiaochen
Published: January 2022

The China's top 10 hematological advances in 2021 was announced at the 2nd Annual Meeting of Chinese Alliance for Societies of Hematology on January 16, 2022.