bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the Nexus between Transitional Justice and Ecoterritorial Conflict Resolution: Time for an Ecoterritorial Turn in Transformative Transitional Justice?
Authors: Kerremans Sarah , Destrooper Tine
Published: January 2023

ABSTRACT∞

This article explores the nexus between ecoterritorial conflict resolution and transformative transitional justice, against the background of (neo)extractivism and the Peruvian case of half a century of oil violence. Our argument is twofold. On the one hand, we argue that transitional justice can act as a conceptual and analytical lens to better understand and further (claims for) change while also countering the invisibilization of ecoterritorial struggles of Indigenous and local communities who resist the framing of their lives and ecosystems as sacrificable or disposable. On the other hand, we argue that reading ecoterritorial struggles through the lens of transitional justice also has implications for the paradigm itself. The article is rooted in the first author’s longstanding work with Indigenous communities in the Peruvian Amazon who engage with transitional justice discourses and practices as part of their struggle against oil violence.
Evaluation and control ofAlternaria alternatacausing leaf spot in soybean in Northeast China
Authors: Li Wenqi , Huang Wei , Zhou Jiangruihang , Wang Jiajun , Liu Jinxin , Li Yonggang
Published: January 2023

Aim

The aims of this study were to characterize the causal agent of soybean leaf spot and determine the pathogenicity of the pathogen to the main crops in Northeast China and detect the sensitivity of pathogens to the main chemical fungicides and the potted control effect.

Methods and results

In 2020 and 2021, an uncommon leaf spot was observed in Harbin, Heilongjiang Province (125°42′-130°10′E, 44°04′-46°40′N), China. The pathogen can infect soybean leaves and cause leaf spot. We collected diseased soybean leaves and isolated four pathogen organisms, all of which were identified as Alternaria alternata through morphological and molecular identification. Koch's postulates were used to confirm pathogenicity. To the best of our knowledge, this is the first report on soybean leaf spot disease caused by A. alternata in northeast China. Moreover, A. alternata had a broad host range and caused leaf spot in most legumes. However, it did not infect medicated lentil (Dolicho Lablab L.) or tobacco (Nicotiana tabacum L.). Assessment of A. alternaria susceptibility to fungicides by spore germination method, isolates of A. alternata were most sensitive to flusilazole, with EC50 values of 0.0040–0.0053 μg ml−1. Through two pot experiments, the average control efficacy of 0.1 mg ml−1 flusilazole on soybean leaf spot caused by A. alternata was 80.7%.

Conclusions

The work reported that A. alternata is the pathogen organism that causes soybean leaf spot in northern China. The pathogen organism can infect a variety of leguminous plants. Considering the control cost and effect, flusilazole is more suitable for controlling leaf spot disease in the field, and benzoxystrobin can be used as an alternative fungicide.
Integrating real-world data to assess cardiac ablation device outcomes in a multicenter study using the OMOP common data model for regulatory decisions: implementation and evaluation
Authors: Yu Yue , Jiang Guoqian , Brandt Eric , Forsyth Tom , Dhruva Sanket S , Zhang Shumin , Chen Jiajing , Noseworthy Peter A , Doshi Amit A , Collison-Farr Kimberly , Kim Dure , Ross Joseph S , Coplan Paul M , Drozda Joseph P
Published: January 2023

The objective of this study is to describe application of the Observational Medical Outcomes Partnership (OMOP) common data model (CDM) to support medical device real-world evaluation in a National Evaluation System for health Technology Coordinating Center (NESTcc) Test-Case involving 2 healthcare systems, Mercy Health and Mayo Clinic. CDM implementation was coordinated across 2 healthcare systems with multiple hospitals to aggregate both medical device data from supply chain databases and patient outcomes and covariates from electronic health record data. Several data quality assurance (QA) analyses were implemented on the OMOP CDM to validate the data extraction, transformation, and load (ETL) process. OMOP CDM-based data of relevant patient encounters were successfully established to support studies for FDA regulatory submissions. QA analyses verified that the data transformation was robust between data sources and OMOP CDM. Our efforts provided useful insights in real-world data integration using OMOP CDM for medical device evaluation coordinated across multiple healthcare systems.
Changes in milk fat globule physical properties and milk fatty acid composition throughout the lactation cycle of Laoshan goat
Authors: Fan Rongbo , Zhang Wenqing , Zhao Xiaowei , Ji Zhongyuan , Du Qijing , Han Rongwei , Wang Jun , Yang Yongxin
Published: January 2023

The objective of this study was to investigate the effect of lactation stage on the physical properties of milk fat globules (MFGs) and profiles of milk fatty acids (FAs) of milk from Laoshan dairy goats. Goat colostrum and milk samples were collected on days 1, 3, 30, 90, 150, and 240 postpartum. Milk fat content was found to significantly decrease during the first 90 d of lactation and increase thereafter as lactation progressed (P < 0.01). Average area particle size and volume particle size of MFGs showed trends similar to those of the milk fat content of goat milk with the extension of lactation, and the lowest levels were 2.39 μm and 3.97 μm on day 90, respectively (P < 0.01). The zeta-potential of MFGs significantly increased before 30 d of lactation, with a slight drop on day 90. It increased thereafter and tended to stabilize in the late stages of lactation (P < 0.01). The content of several saturated fatty acids (SFAs) (C10:0-C16:0) in early lactation, especially in colostrum, was lower than that in other stages of lactation (P < 0.05). Branched-chain fatty acids of the iso and anteiso series, including C13:0 anteiso, C15:0 anteiso, and C15:0 iso, were observed at high contents in mid-lactation goat milk (P < 0.01). As lactation progressed (3 d to 240 d), the content of SFAs significantly increased (P < 0.01), while the content of monounsaturated fatty acids and polyunsaturated fatty acids significantly decreased (P < 0.05). Furthermore, the content of C18:0 significantly increased during the first 30 d of lactation and decreased thereafter as lactation progressed (P < 0.01). Our results indicated that lactation stage has a pronounced effect on the physical properties of MFGs and the FA profiles of goat milk.
Different platforms, different uses: testing the effect of platforms and individual differences on perception of incivility and self-reported uncivil behavior
Authors: Sude Daniel J , Dvir-Gvirsman Shira
Published: January 2023

Two large surveys with adult samples of Americans (N = 1,105; N = 1,035) investigated differences in perceived incivility between seven social media platforms. Perceptions of incivility were targeted, given both their inherent societal relevance and the personalized nature of each user’s platform experience. Utilizing a novel approach, observations per platform were nested within each user, facilitating disentangling user-level from platform-level factors. Study 1 demonstrated that even accounting for differences between users, perceptions vary by platform. Further, while individual users do admit to generating uncivil content themselves, self-perceptions were in contrast largely stable across platforms. Study 2 built upon Study 1 by investigating additional platform-level factors that could impact perceptions of incivility: Differences in perceived affordances between platforms were related to differences in perceptions of incivility’s prevalence. Specifically, platforms characterized by either perceived anonymity or perceived network association were in turn perceived to be more uncivil.
Language use in online support provision: the impact of others’ supportive messages, support-seeking strategy, and channel publicness
Authors: Zhou Yanmengqian , High Andrew C
Published: January 2023

People benefit from high-quality supportive messages online, yet the production of these messages is a complex process that is shaped by multiple factors. As informed by the lens model, this study seeks to investigate the interplay of third party’s supportive messages as a form of behavioral residue and the support seeker’s seeking strategy as an identity claim on providers’ language use in supportive messages conveyed in public and private channels online. Data showed that providers’ use of words that differentiate supportive messages of varying quality (i.e., first-person singular pronouns, second-person pronouns, social process words, cognitive process words, and anxiety words) was influenced by the quality and quantity of others’ comments, the support-seeking strategy, and the publicness of the communication channel in an interactive way. Findings extend the literature by providing a more comprehensive account of online supportive communication and illuminating the actual language used to support others.
The One-Child Policy and Household Saving
Authors: Choukhmane Taha , Coeurdacier Nicolas , Jin Keyu
Published: January 2023

We investigate whether the “one-child policy” has contributed to the rise in China’s household saving rate and human capital in recent decades. In a life-cycle model with intergenerational transfers and human capital accumulation, fertility restrictions lower expected old-age support coming from children—inducing parents to raise saving and education investment in their offspring. Quantitatively, the policy can account for at least 30% of the rise in aggregate saving. Using the birth of twins under the policy as an empirical out-of-sample check to the theory, we find that quantitative estimates on saving and education decisions line up well with micro-data.
Developing Consensus on Clinical Outcomes for Children with Mild Pneumonia: A Delphi Study
Authors: Florin Todd A , Melnikow Joy , Gosdin Melissa , Ciuffetelli Ryan , Benedetti Jillian , Ballard Dustin , Gausche-Hill Marianne , Kronman Matthew P , Martin Lisa A , Mistry Rakesh D , Neuman Mark I , Palazzi Debra L , Patel Sameer J , Self Wesley H , Shah Samir S , Shah Sonal N , Sirota Susan , Cruz Andrea T , Ruddy Richard , Gerber Jeffrey S , Kuppermann Nathan
Published: January 2023

Background

The absence of consensus for outcomes in pediatric antibiotic trials is a major barrier to research harmonization and clinical translation. We sought to develop expert consensus on study outcomes for clinical trials of children with mild community-acquired pneumonia (CAP).

Methods

Applying the Delphi method, a multispecialty expert panel ranked the importance of various components of clinical response and treatment failure outcomes in children with mild CAP for use in research. During Round 1, panelists suggested additional outcomes in open-ended responses that were added to subsequent rounds of consensus building. For Rounds 2 and 3, panelists were provided their own prior responses and summary statistics for each item in the previous round. The consensus was defined by >70% agreement.

Results

The expert panel determined that response to and failure of treatment should be addressed at a median of 3 days after initiation. Complete or substantial improvement in fever, work of breathing, dyspnea, tachypnea when afebrile, oral intake, and activity should be included as components of adequate clinical response outcomes. Clinical signs and symptoms including persistent or worsening fever, work of breathing, and reduced oral intake should be included in treatment failure outcomes. Interventions including receipt of parenteral fluids, supplemental oxygen, need for high-flow nasal cannula oxygen therapy, and change in prescription of antibiotics should also be considered in treatment failure outcomes.

Conclusions

Clinical response and treatment failure outcomes determined by the consensus of this multidisciplinary expert panel can be used for pediatric CAP studies to provide objective data translatable to clinical practice.
Littre’s hernia—a reason for resection
Authors: Seok David , Akrawe Silvy , Mittal Vijay
Published: January 2023

Littre’s hernias are exceedingly rare, with an estimated incidence of 0.09% in strangulated or incarcerated hernias. It may present as a complication of Meckel’s diverticulum in less than 1%. In the adult population, it presents as an inguinal (50%), femoral (20%) and umbilical (20%) hernias. Management of Meckel’s diverticulum when encountered during a routine repair of hernia in literature is generally resection. We present a case of a healthy 68-year-old gentleman who was found to have a Meckel’s diverticulum in the indirect hernia sac during routine elective open right inguinal hernia repair.
Nodulocystic basal cell carcinoma on the limb masquerading as vascular malformation on imaging
Authors: Ng Hung Shin Paul Brian , Tie Bibiana , Kanagarajah Vijay , Tan Ailin
Published: January 2023

Nodulocystic basal cell carcinoma (BCC) is a cystic variant of BCC, which can easily be misdiagnosed. We report a case of a 52-year-old man with a nodulocystic BCC that appeared at the site of a previously excised BCC 9 years prior. It examined as a benign cyst with a radiological signature of a vascular malformation. It was histologically confirmed on fine needle aspirate (FNA) and excisional biopsy to be a nodulocystic BCC. BCC is one of the most common paraneoplastic neoplasms affecting photo-exposed areas and displaying many variants. Nodulocystic BCC is a rarer variant that may have more than one dermoscopic face and can appear macroscopically benign. Given its malignant potential, it is imperative that it is accurately diagnosed. We highlighted that nodular cystic BCC can easily be misdiagnosed. Careful history and FNA are key differentiators to establish the correct diagnosis.
Management of fulminating non-cardiogenic pulmonary edema following cardiac surgery
Authors: Arima Takahiro , Tatebayashi Takayuki , Noji Sakashi
Published: January 2023

A malignant form of non-cardiogenic pulmonary edema (NCPE) that develops soon after the termination of cardiopulmonary bypass support during cardiac surgery is rarely encountered. It sometimes requires immediate management, including venovenous extracorporeal membrane oxygenation (VV-ECMO). In the first case, a 78-year-old female patient experienced fulminating NCPE after mitral valve plasty, which caused severe respiratory failure and hemodynamic instability due to a huge amount of sputum. In the second case, a 47-year-old male patient presented with right-sided unilateral pulmonary edema with a substantial amount of sputum after minimally invasive cardiac surgery for mitral valve repair. In both cases, VV-ECMO and aggressive fluid replacement were promptly initiated. The NCPE resolved on post-operative day 2, resulting in the successful termination of VV-ECMO. NCPE leads to lethal respiratory failure with multifactorial causes during cardiac surgery. However, as NCPE is potentially transient, immediate treatment comprising VV-ECMO and aggressive fluid replacement can improve clinical outcomes.
Unexpected finding of leiomyoma during laparoscopic gastric sleeve: a case report
Authors: Pérez Corzo Héctor Joaquín , Romero Suárez Angélica Katherine , Salgado Salas Roberto Esau , Nieto Segura Felipe , Verboonen Sotelo José Sergio , Romero Manzano Jeffry , Guzmán Barba José Aldo , Esparza Estrada Isaac
Published: January 2023

Obesity is a chronic disease with pandemic levels of prevalence worldwide. The most often performed bariatric procedure is sleeve gastrectomy. Although the patient’s history may not indicate preoperative imaging studies, coincidental findings of unexpected pathology are not uncommon, such as leiomyoma. A 41-year-old female was scheduled to laparoscopic gastric sleeve with no contraindications for surgery. A tumor-like mass was identified on the left lateral face of the distal third of the esophagus. Trans-surgical endoscopy and pneumatic test were performed to rule out any type of communication. The surgeon managed to remove the tumor mass, that was sent to histopathological study, and concluded the procedure without complications. Benign tumors of the esophagus are rarely found lesions. Occasionally unexpected findings may occur during surgery, and they should be resolved intraoperatively when possible to allow the completion of the originally planned surgical procedure.
Postoperative chylothorax after left pulmonary wedge resection without mediastinal lymph node dissection: a case report
Authors: Chen Li , Tian Bo , Xie Shaohua , Wei Xing , Li Qiang , Hu Bin
Published: January 2023

Postoperative chylothorax is a rare but serious complication after pulmonary resection. In previous studies, we have found no reports of postoperative chylothorax after left pulmonary wedge resection. Considering the many variations in the route of the thoracic duct, it also has the risk of postoperative chylothorax. We describe a case of refractory chylothorax after left pulmonary wedge resection without mediastinal lymph node dissection. Conservative treatment and supradiaphragmatic thoracic duct ligation did not obtain satisfactory results in this patient. Finally, under the guidance of magnetic resonance–thoracic ductography (MRTD), we successfully ligated the thoracic duct fistula. Thus, MRTD may contribute positively to being used to locate the thoracic duct and its fistula to support precise surgical intervention.
Fast and accurate predictions of the non-linear matter power spectrum for general models of Dark Energy and Modified Gravity
Authors: Bose B , Tsedrik M , Kennedy J , Lombriser L , Pourtsidou A , Taylor A
Published: January 2023

We embed linear and non-linear parametrizations of beyond standard cosmological physics in the halo model reaction framework, providing a model-independent prescription for the non-linear matter power spectrum. As an application, we focus on Horndeski theories, using the Effective Field Theory of Dark Energy (EFTofDE) to parametrize linear and quasi-non-linear perturbations. In the non-linear regime, we investigate both a non-linear parametrized post-Friedmann (nPPF) approach as well as a physically motivated and approximate phenomenological model based on the error function (Erf). We compare the parametrized approaches’ predictions of the non-linear matter power spectrum to the exact solutions, as well as state-of-the-art emulators, in an evolving dark energy scenario and two well-studied modified gravity models, finding sub-per cent agreement in the reaction using the Erf model at z ≤ 1 and k ≤ 5 h Mpc−1. This suggests only an additional three free constants, above the background and linear theory parameters, are sufficient to model non-linear, non-standard cosmology in the matter power spectrum at scales down to k ≤ 3h Mpc−1 within $2{{\ \rm per\ cent}}$ accuracy. We implement the parametrizations into ver.2.0 of the ReACT code: ACTio et ReACTio.
Hybrid pulsar–magnetar model for FRB 20191221A
Authors: Beniamini Paz , Kumar Pawan
Published: January 2023

We show that the 216.8 ± 0.1 ms periodicity reported for the fast radio burst (FRB) 20191221A is very constraining for burst models. The high accuracy of burst periodicity (better than one part in 103), and the 2 per cent duty cycle (ratio of burst duration and interburst interval), suggest a pulsar-like rotating beam model for the observed activity; the radio waves are produced along open field lines within ∼107 cm of the neutron star surface, and the beam periodically sweeps across the observer as the star spins. According to this picture, FRB 20191221A is a factor ∼1012 scaled up version of galactic pulsars with one major difference, whereas pulsars convert rotational kinetic energy to EM waves and the outbursts of 20191221A require conversion of magnetic energy to radiation.
Diffusion velocity of metals in Ap star atmospheres: the effect of ambipolar diffusion of H
Authors: Alecian G
Published: January 2023

Ambipolar diffusion of hydrogen is effective in the atmosphere of stars when hydrogen is partially ionized. This is precisely the case for Ap stars whose atmospheres are stable enough to allow atomic diffusion in building metals stratification. Now, ambipolar diffusion of H induces an additional term to the diffusion velocity usually considered for metals. For some chemical elements, this may significantly affect the diffusion flux, and so, their abundance distribution. This effect decreases for high effective temperatures since protons density becomes very dominant compared to neutral H (that is partial ionization of H may be neglected), and so, this process has been neglected in recent models of abundance distributions in Bp stars. In this study, we evaluate for many metals the role of ambipolar diffusion in view of future detailed modelling of atomic diffusion for chemically peculiar stars with $T_{\rm eff}\lesssim 12\, 000$ K. We discuss a possible effect that we name the ambipolar flooding.
The brightest galaxies at cosmic dawn
Authors: Mason Charlotte A , Trenti Michele , Treu Tommaso
Published: January 2023

Recent JWST observations suggest an excess of z ≳ 10 galaxy candidates above most theoretical models. Here, we explore how the interplay between halo formation time-scales, star formation efficiency, and dust attenuation affects the properties and number densities of galaxies observed in the early Universe. To guide intuition, we calculate the theoretical upper limit on the UV luminosity function (LF), assuming star formation is 100 per cent efficient and all gas in haloes is converted into stars, and that galaxies are at the peak age for UV emission (∼10 Myr). This upper limit is ∼4 orders of magnitude greater than current observations, implying no formal tension with star formation in Lambda cold dark matter cosmology. In a more realistic model, we use the distribution of halo formation time-scales derived from extended Press–Schechter theory as a proxy for star formation rate (SFR). We predict that the galaxies observed so far at z ≳ 10 are dominated by those with the fastest formation time-scales, and thus most extreme SFRs and young ages. These galaxies can be upscattered by ∼1.5 mag compared to the median UV magnitude versus halo mass relation. This likely introduces a selection effect at high redshift whereby only the youngest (≲10 Myr), most highly star-forming galaxies (specific SFR$\gtrsim 30\, \mathrm{Gyr}^{-1}$) have been detected so far. Furthermore, our modelling suggests that redshift evolution at the bright end of the UV LF is substantially affected by the build-up of dust attenuation. We predict that deeper JWST observations (reaching m ∼ 30) will reveal more typical galaxies with relatively older ages (∼100 Myr) and less extreme specific SFRs ($\sim 10\, \mathrm{Gyr}^{-1}$ for a MUV ∼ −20 galaxy at z ∼ 10).
Changes in the distribution of circum-binary material around the HMXB GX 301-2 during a rapid spin-up episode of the neutron star
Authors: Manikantan Hemanth , Paul Biswajit , Roy Kinjal , Rana Vikram
Published: January 2023

Some accretion-powered X-ray pulsars with supergiant companion stars undergo occasional rapid spin-up episodes that last for weeks to a few months. We explore the changes in the accretion environment of the pulsar GX 301-2 during its latest 80 days long spin-up episode in 2019 when the spin frequency of the pulsar increased by ∼2 per cent over two orbits of the binary. By performing time-resolved spectroscopy with the MAXI/GSC spectra of the source, we estimated the equivalent hydrogen column density and equivalent width of the iron fluorescence line during the spin-up episode, and compared them with the long-term average values estimated by orbital-phase-resolved spectroscopy. The measured absorption column density during the spin-up episode is about twice that of an average orbit, while the equivalent width of the iron line is less than half of an average orbit. Though the spin-up episode started immediately after a pre-periastron flare and lasted for the two consecutive orbits of the binary, the associated enhancement in luminosity started a few days after the pre-periastron flare and lasted only during the first orbit, and some enhancement was seen again during the pre-periastron passage of the second orbit. The absorption column density and iron line equivalent width vary throughout the spin-up episode and are distinct from an average orbit. These observations indicate a significant change in the accretion and reprocessing environment in GX 301-2 during the spin-up episode and may hold important clues for the phenomenon in this source and several other sources with supergiant companions.
Radio detections of two unusual cataclysmic variables in the VLA Sky Survey
Authors: Ridder M E , Heinke C O , Sivakoff G R , Hughes A K
Published: January 2023

We report two new radio detections of cataclysmic variables (CVs), and place them in context with radio and X-ray detections of other CVs. We detected QS Vir, a low accretion-rate CV; V2400 Oph, a discless intermediate polar; and recovered the polar AM Her in the Very Large Array Sky Survey 2–4 GHz radio images. The radio luminosities of these systems are higher than typically expected from coronal emission from stars of similar spectral types, and neither system is expected to produce jets, leaving the origin of the radio emission a puzzle. The radio emission mechanism for these two CVs may be electron–cyclotron maser emission, synchrotron radiation, or a more exotic process. We compile published radio detections of CVs, and X-ray measurements of these CVs, to illustrate their locations in the radio–X-ray luminosity plane, a diagnostic tool often used for X-ray binaries, active galactic nuclei, and radio stars. Several radio-emitting CVs, including these two newly detected CVs, seem to lie near the principal radio/X-ray track followed by black hole X-ray binaries at low luminosity, suggesting additional complexity in classifying unknown systems using their radio and X-ray luminosities alone.
A closer look at low-mass post-AGB late thermal pulses
Authors: Lawlor T M
Published: January 2023

Late thermal pulse (LTP) stellar evolution models experience a helium pulse that occurs following asymptotic giant branch (AGB) departure and causes a rapid looping evolution in the Hertzsprung–Russell (HR) diagram between the AGB and planetary nebula (PN) phase. The transient LTP phases only last decades to centuries while increasing and decreasing in temperature, luminosity, and size over orders of magnitude. LTP objects have often been described in the context of their more dramatic counterparts, very late thermal pulses (VLTPs). LTP stars do not evolve as quickly and do not become as hydrogen deficient as VLTP objects. They do not become conspicuous until after resembling a PN for thousands of years. We present stellar evolution calculations from the AGB to the PN phase for models over a range of metallicities from Z = 0.0015 to 0.03, and for masses 0.90, 1.2, and 2.0 ${\rm M_{\odot }}$. We focus in on our most dense series (1.2 ${\rm M_{\odot }}$, Z = 0.015) and designate a stratification of LTP types based on at what temperature they erupt, which may hint at the progenitor mass. We discuss one type that fits neither an LTP nor VLTP, which may offer an explanation for the star FG Sge. We present the time-scales during which LTP models heat up until reach peak helium-burning luminosity, during the rapid luminosity decline, and during the period of cooling and brightening, and we briefly discuss four LTP candidates.
Discovery of two cyclotron resonance scattering features in X-ray pulsar cen X-3 by Insight-HXMT
Authors: Yang W , Wang W , Liu Q , Chen X , Wu H J , Tian P F , Chen J S
Published: January 2023

We present the results of the neutron star X-ray binary system Cen X-3 performed by Insight-HXMT with two observations during 2017 and 2018. During these two observations, the source reached a X-ray luminosity of ∼1038 erg s−1 from 2–105 keV. The analysis of the broadband X-ray spectrum reports the presence of two cyclotron resonance scattering features (CRSFs) with the fundamental line at ∼ 28 keV and the harmonic line at ∼47 keV. The multiple lines exist by fittings with different continuum models, like the absorbed negative and positive power-law with an exponential cutoff (NPEX) model and a power-law with high energy exponential cutoff model. This is the first time that both fundamental and harmonic lines are detected in Cen X-3. We also show evidence of two cyclotron lines in the phase-resolved spectrum of Cen X-3. The CRSF and continuum spectral parameters show evolution with the pulse profile, and the two line centroid energy ratio does not change significantly and locates in a narrow value range of 1.6−1.7 over the pulse phase. The implications of the discovering two cyclotron absorption features and phase-resolved spectral properties are discussed.
Reconstructing large-scale temperature profiles around z ∼ 6 quasars
Authors: Chen Huanqing , Croft Rupert A C , Gnedin Nickolay Y
Published: January 2023

High-redshift quasars ionize He ii into He iii around them, heating the intergalactic medium in the process and creating large regions with elevated temperature. In this work, we demonstrate a method based on a convolutional neural network (CNN) to recover the spatial profile for T0, the temperature at the mean cosmic density, in quasar proximity zones. We train the neural network with synthetic spectra drawn from a Cosmic Reionization on Computers simulation. We discover that the simple CNN is able to recover the temperature profile with an accuracy of ≈1400 K in an idealized case of negligible observational uncertainties. We test the robustness of the CNN and discover that it is robust against the uncertainties in quasar host halo mass, quasar continuum, and ionizing flux. We also find that the CNN has good generality with regard to the hardness of quasar spectra. This shows that with noiseless spectra, one could use a simple CNN to distinguish gas inside or outside the He iii region created by the quasar. Because the size of the He iii region is closely related to the total quasar lifetime, this method has great potential in constraining the quasar lifetime on ∼Myr time-scales. However, noise poses a big problem for accuracy and could downgrade the accuracy to ≈2340 K even for very high signal-to-noise (≳50) spectra. Future studies are needed to reduce the error associated with noise to constrain the lifetimes of reionization epoch quasars with currently available data.
The impact of spurious collisional heating on the morphological evolution of simulated galactic discs
Authors: Wilkinson Matthew J , Ludlow Aaron D , Lagos Claudia del P , Fall S Michael , Schaye Joop , Obreschkow Danail
Published: January 2023

We use a suite of idealized N-body simulations to study the impact of spurious heating of star particles by dark matter (DM) particles on the kinematics and morphology of simulated galactic discs. We find that spurious collisional heating leads to a systematic increase of the azimuthal velocity dispersion (σϕ) of stellar particles and a corresponding decrease in their mean azimuthal velocities ($\overline{v}_\phi$). The rate of heating is dictated primarily by the number of DM halo particles (or equivalently, by the DM particle mass at fixed halo mass) and by radial gradients in the local DM density along the disc; it is largely insensitive to the stellar particle mass. Galaxies within haloes resolved with fewer than ≈106 DM particles are particularly susceptible to spurious morphological evolution, irrespective of the total halo mass (with even more particles required to prevent heating of the galactic centre). Collisional heating transforms galactic discs from flattened structures into rounder spheroidal systems, causing them to lose rotational support in the process. It also affects the locations of galaxies in standard scaling relations that link their various properties: at fixed stellar mass, it increases the sizes of galaxies, and reduces their mean stellar rotation velocities and specific angular momenta. Our results urge caution when extrapolating simulated galaxy scaling relations to low masses where spurious collisional effects can bias their normalization, slope, and scatter.
Galaxy fields of LISA massive black hole mergers in a simulated universe
Authors: Lops Gaia , Izquierdo-Villalba David , Colpi Monica , Bonoli Silvia , Sesana Alberto , Mangiagli Alberto
Published: January 2023

Laser Interferometer Space Antenna (LISA) will extend the search for gravitational waves (GWs) at $0.1\, {-}\, 100$ mHz where loud signals from coalescing binary black holes of $10^4 \, {-}\, 10^7\, \, \rm {M}_{\odot }$ are expected. Depending on their mass and luminosity distance, the uncertainty in the LISA sky-localization decreases from hundreds of deg2 during the inspiral phase to fractions of a deg2 after the merger. By using the semi-analytical model L-Galaxies applied to the Millennium-I merger trees, we generate a simulated universe to identify the hosts of $z\, {\le }\, 3$ coalescing binaries with total mass of $3\, {\times }\, 10^{5}$, $3\, {\times }\, 10^6$, and $3\, {\times }\, 10^7\, \rm {M}_{\odot }$, and varying mass ratio. We find that, even at the time of merger, the number of galaxies around the LISA sources is too large (${\gtrsim }\, 10^2$) to allow direct host identification. However, if an X-ray counterpart is associated to the GW sources at $z\, {< }\, 1$, all LISA fields at merger are populated by ${\lesssim }\, 10$ active galactic nuclei (AGNs) emitting above ${\sim }\, 10^{-17} \, \rm erg\, cm^{-2}\, s^{-1}$. For sources at higher redshifts, the poorer sky-localization causes this number to increase up to ${\sim }\, 10^3$. Archival data from eRosita will allow discarding ${\sim }\, 10{{\ \rm per\ cent}}$ of these AGNs, being too shallow to detect the dim X-ray luminosity of the GW sources. Inspiralling binaries in an active phase with masses ${\lesssim }\, 10^6\, \rm {M}_{\odot }$ at $z\, {\le }\, 0.3$ can be detected, as early as 10 h before the merger, by future X-ray observatories in less than a few minutes. For these systems, ${\lesssim }\, 10$ AGNs are within the LISA sky-localization area. Finally, the LISA-Taiji network would guarantee the identification of an X-ray counterpart 10 h before merger for all binaries at $z\, {\lesssim }\, 1$.
Optical/γ-ray blazar flare correlations: understanding the high-energy emission process using ASAS-SN and Fermi light curves
Authors: de Jaeger T , Shappee B J , Kochanek C S , Hinkle J T , Garrappa S , Liodakis I , Franckowiak A , Stanek K Z , Beacom J F , Prieto J L
Published: January 2023

Using blazar light curves from the optical All-Sky Automated Survey for Supernovae (ASAS-SN) and the γ-ray Fermi-LAT telescope, we performed the most extensive statistical correlation study between both bands, using a sample of 1180 blazars. This is almost an order of magnitude larger than other recent studies. Blazars represent more than 98 per cent of the AGNs detected by Fermi-LAT and are the brightest γ-ray sources in the extragalactic sky. They are essential for studying the physical properties of astrophysical jets from central black holes. However, their γ-ray flare mechanism is not fully understood. Multiwavelength correlations help constrain the dominant mechanisms of blazar variability. We search for temporal relationships between optical and γ-ray bands. Using a Bayesian Block Decomposition, we detect 1414 optical and 510 γ-ray flares, we find a strong correlation between both bands. Among all the flares, we find 321 correlated flares from 133 blazars, and derive an average rest-frame time delay of only 1.1$_{-8.5}^{+7.1}$ d, with no difference between the flat-spectrum radio quasars, BL Lacertae-like objects or low, intermediate, and high-synchrotron peaked blazar classes. Our time-delay limit rules out the hadronic proton-synchrotron model as the driver for non-orphan flares and suggests a leptonic single-zone model. Limiting our search to well-defined light curves and removing 976 potential but unclear ‘orphan’ flares, we find 191 (13 per cent) and 115 (22 per cent) clear ‘orphan’ optical and γ-ray flares. The presence of ‘orphan’ flares in both bands challenges the standard one-zone blazar flare leptonic model and suggests multizone synchrotron sites or a hadronic model for some blazars.
Tracking the origin of black holes with the stochastic gravitational wave background popcorn signal
Authors: Braglia Matteo , García-Bellido Juan , Kuroyanagi Sachiko
Published: January 2023

Unresolved sources of gravitational waves (GWs) produced by the merger of a binary of black holes at cosmological distances combine into a stochastic background. Such a background is in the continuous or popcorn regime, depending on whether the GW rate is high enough so that two or more events overlap in the same frequency band. These two regimes respectively correspond to large and small values of the so-called duty cycle. We study the detection regime of the background in models of primordial black holes (PBHs) and compare it to the one produced by black holes of stellar origin. Focusing on ground-based detectors, we show that the duty cycle of the PBH-origin background is larger than that of astrophysical black holes because of differences in their mass function and the merger rate. Our study opens up the possibility to learn about the primordial or astrophysical nature of black hole populations by examining the statistical properties of the stochastic background.
Pervasive Selection for Clinically Relevant Resistance and Media Adaptive Mutations at Very Low Antibiotic Concentrations
Authors: Pereira Catia , Warsi Omar M , Andersson Dan I
Published: January 2023

Experimental evolution studies have shown that weak antibiotic selective pressures (i.e., when the antibiotic concentrations are far below the minimum inhibitory concentration, MIC) can select resistant mutants, raising several unanswered questions. First, what are the lowest antibiotic concentrations at which selection for de novo resistance mutations can occur? Second, with weak antibiotic selections, which other types of adaptive mutations unrelated to the antibiotic selective pressure are concurrently enriched? Third, are the mutations selected under laboratory settings at subMIC also observed in clinical isolates? We addressed these questions using Escherichia coli populations evolving at subMICs in the presence of either of four clinically used antibiotics: fosfomycin, nitrofurantoin, tetracycline, and ciprofloxacin. Antibiotic resistance evolution was investigated at concentrations ranging from 1/4th to 1/2000th of the MIC of the susceptible strain (MICsusceptible). Our results show that evolution was rapid across all the antibiotics tested, and selection for fosfomycin- and nitrofurantoin-resistant mutants was observed at a concentration as low as 1/2000th of MICsusceptible. Several of the evolved resistant mutants showed increased growth yield and exponential growth rates, and outcompeted the susceptible ancestral strain in the absence of antibiotics as well, suggesting that adaptation to the growth environment occurred in parallel with the selection for resistance. Genomic analysis of the resistant mutants showed that several of the mutations selected under these conditions are also found in clinical isolates, demonstrating that experimental evolution at very low antibiotic levels can help in identifying novel mutations that contribute to bacterial adaptation during subMIC exposure in real-life settings.
Influence of chain length and branching on poly(ADP-ribose)–protein interactions
Authors: Löffler Tobias , Krüger Annika , Zirak Peyman , Winterhalder Martin J , Müller Anna-Lena , Fischbach Arthur , Mangerich Aswin , Zumbusch Andreas
Published: January 2023

Hundreds of proteins interact with poly(ADP-ribose) (PAR) via multiple PAR interaction motifs, thereby regulating their physico-chemical properties, sub-cellular localizations, enzymatic activities, or protein stability. Here, we present a targeted approach based on fluorescence correlation spectroscopy (FCS) to characterize potential structure-specific interactions of PAR molecules of defined chain length and branching with three prime PAR-binding proteins, the tumor suppressor protein p53, histone H1, and the histone chaperone APLF. Our study reveals complex and structure-specific PAR–protein interactions. Quantitative Kd values were determined and binding affinities for all three proteins were shown to be in the nanomolar range. We report PAR chain length dependent binding of p53 and H1, yet chain length independent binding of APLF. For all three PAR binders, we found a preference for linear over hyperbranched PAR. Importantly, protein- and PAR-structure-specific binding modes were revealed. Thus, while the H1-PAR interaction occurred largely on a bi-molecular 1:1 basis, p53—and potentially also APLF—can form complex multivalent PAR–protein structures. In conclusion, our study gives detailed and quantitative insight into PAR–protein interactions in a solution-based setting at near physiological buffer conditions. The results support the notion of protein and PAR-structure-specific binding modes that have evolved to fit the purpose of the respective biochemical functions and biological contexts.
Human DNA ligases I and III have stand-alone end-joining capability, but differ in ligation efficiency and specificity
Authors: McNally Justin R , Ames Amanda M , Admiraal Suzanne J , O’Brien Patrick J
Published: January 2023

Double-strand DNA breaks (DSBs) are toxic to cells, and improper repair can cause chromosomal abnormalities that initiate and drive cancer progression. DNA ligases III and IV (LIG3, LIG4) have long been credited for repair of DSBs in mammals, but recent evidence suggests that DNA ligase I (LIG1) has intrinsic end-joining (EJ) activity that can compensate for their loss. To test this model, we employed in vitro biochemical assays to compare EJ by LIG1 and LIG3. The ligases join blunt-end and 3′-overhang-containing DNA substrates with similar catalytic efficiency, but LIG1 joins 5′-overhang-containing DNA substrates ∼20-fold less efficiently than LIG3 under optimal conditions. LIG1-catalyzed EJ is compromised at a physiological concentration of Mg2+, but its activity is restored by increased molecular crowding. In contrast to LIG1, LIG3 efficiently catalyzes EJ reactions at a physiological concentration of Mg2+ with or without molecular crowding. Under all tested conditions, LIG3 has greater affinity than LIG1 for DNA ends. Remarkably, LIG3 can ligate both strands of a DSB during a single binding encounter. The weaker DNA binding affinity of LIG1 causes significant abortive ligation that is sensitive to molecular crowding and DNA terminal structure. These results provide new insights into mechanisms of alternative nonhomologous EJ.
Observation of dark edge states in parity-time-symmetric quantum dynamics
Authors: Xue Peng , Qiu Xingze , Wang Kunkun , Sanders Barry C , Yi Wei
Published: January 2023

Topological edge states arise in non-Hermitian parity-time ($\mathcal {PT}$)-symmetric systems, and manifest themselves as bright or dark edge states, depending on the imaginary components of their eigenenergies. As the spatial probabilities of dark edge states are suppressed during the non-unitary dynamics, it is a challenge to observe them experimentally. Here we report the experimental detection of dark edge states in photonic quantum walks with spontaneously broken $\mathcal {PT}$ symmetry, thus providing a complete description of the topological phenomena therein. We experimentally confirm that the global Berry phase in $\mathcal {PT}$-symmetric quantum-walk dynamics unambiguously defines topological invariants of the system in both the $\mathcal {PT}$-symmetry-unbroken and -broken regimes. Our results establish a unified framework for characterizing topology in $\mathcal {PT}$-symmetric quantum-walk dynamics, and provide a useful method to observe topological phenomena in $\mathcal {PT}$-symmetric non-Hermitian systems in general.
The smallest in the deepest: the enigmatic role of viruses in the deep biosphere
Authors: Cai Lanlan , Weinbauer Markus G , Xie Le , Zhang Rui
Published: January 2023

It is commonly recognized that viruses control the composition, metabolism, and evolutionary trajectories of prokaryotic communities, with resulting vital feedback on ecosystem functioning and nutrient cycling in a wide range of ecosystems. Although the deep biosphere has been estimated to be the largest reservoir for viruses and their prokaryotic hosts, the biology and ecology of viruses therein remain poorly understood. The deep virosphere is an enigmatic field of study in which many critical questions are still to be answered. Is the deep virosphere simply a repository for deeply preserved, non-functioning virus particles? Or are deep viruses infectious agents that can readily infect suitable hosts and subsequently shape microbial populations and nutrient cycling? Can the cellular content released by viral lysis, and even the organic structures of virions themselves, serve as the source of bioavailable nutrients for microbial activity in the deep biosphere as in other ecosystems? In this review, we synthesize our current knowledge of viruses in the deep biosphere and seek to identify topics with the potential for substantial discoveries in the future.
Leaded aviation gasoline exposure risk and child blood lead levels
Authors: Zahran Sammy , Keyes Christopher , Lanphear Bruce
Published: January 2023

Lead-formulated aviation gasoline (avgas) is the primary source of lead emissions in the United States today, consumed by over 170,000 piston-engine aircraft (PEA). The U.S. Environmental Protection Agency (EPA) estimates that four million people reside within 500m of a PEA-servicing airport. The disposition of avgas around such airports may be an independent source of child lead exposure. We analyze over 14,000 blood lead samples of children (≤5 y of age) residing near one such airport—Reid-Hillview Airport (RHV) in Santa Clara County, California. Across an ensemble of tests, we find that the blood lead levels (BLLs) of sampled children increase in proximity to RHV, are higher among children east and predominantly downwind of the airport, and increase with the volume of PEA traffic and quantities of avgas sold at the airport. The BLLs of airport-proximate children are especially responsive to an increase in PEA traffic, increasing by about 0.72 μg/dL under periods of maximum PEA traffic. We also observe a significant reduction in child BLLs from a series of pandemic-related interventions in Santa Clara County that contracted PEA traffic at the airport. Finally, we find that children’s BLLs increase with measured concentrations of atmospheric lead at the airport. In support of the scientific adjudication of the EPAs recently announced endangerment finding, this in-depth case study indicates that the deposition of avgas significantly elevates the BLLs of at-risk children.