bluuebunny/crossref_metadata_2025 huggingface dataset:
‘Hot phase’ clinical presentation in arrhythmogenic cardiomyopathy
Authors: Bariani Riccardo , Cipriani Alberto , Rizzo Stefania , Celeghin Rudy , Bueno Marinas Maria , Giorgi Benedetta , De Gaspari Monica , Rigato Ilaria , Leoni Loira , Zorzi Alessandro , De Lazzari Manuel , Rampazzo Alessandra , Iliceto Sabino , Thiene Gaetano , Corrado Domenico , Pilichou Kalliopi , Basso Cristina , Perazzolo Marra Martina , Bauce Barbara
Published: October 2020

Aims

The aim of this study is to evaluate the clinical features of patients affected by arrhythmogenic cardiomyopathy (AC), presenting with chest pain and myocardial enzyme release in the setting of normal coronary arteries (‘hot phase’).

Methods and results

We collected detailed anamnestic, clinical, instrumental, genetic, and histopathological findings as well as follow-up data in a series of AC patients who experienced a hot phase. A total of 23 subjects (12 males, mean age at the first episode 27 ± 16 years) were identified among 560 AC probands and family members (5%). At first episode, 10 patients (43%) already fulfilled AC diagnostic criteria. Twelve-lead electrocardiogram recorded during symptoms showed ST-segment elevation in 11 patients (48%). Endomyocardial biopsy was performed in 11 patients, 8 of them during the acute phase showing histologic evidence of virus-negative myocarditis in 88%. Cardiac magnetic resonance was performed in 21 patients, 12 of them during the acute phase; oedema and/or hyperaemia were detected in 7 (58%) and late gadolinium enhancement in 11 (92%). At the end of follow-up (mean 17 years, range 1–32), 12 additional patients achieved an AC diagnosis. Genetic testing was positive in 77% of cases and pathogenic mutations in desmoplakin gene were the most frequent. No patient complained of sustained ventricular arrhythmias or died suddenly during the ‘hot phase’.

Conclusion

‘Hot phase’ represents an uncommon clinical presentation of AC, which often occurs in paediatric patients and carriers of desmoplakin gene mutations. Tissue characterization, family history, and genetic test represent fundamental diagnostic tools for differential diagnosis.
Socioeconomic position and risk of unplanned hospitalization among nursing home residents: a nationwide cohort study
Authors: Allers Katharina , Calderón-Larrañaga Amaia , Fors Stefan , Morin Lucas
Published: October 2020

Background

Socioeconomic inequalities in health and healthcare use in old age have been on the rise during the past two decades. So far, it is unknown whether these inequalities have permeated the nursing home setting. This study aimed to assess whether the socioeconomic position of newly admitted nursing home residents had an influence on their risk of unplanned hospitalization.

Methods

We identified older persons (≥75 years) who were newly admitted to a nursing home between March 2013 and December 2014 using a set of linked routinely collected administrative and healthcare data in Sweden. The number of unplanned hospitalizations for any cause and the cumulative length of stay were defined as primary outcomes. Unplanned hospitalizations for potentially avoidable causes (i.e. fall-related injuries, urinary tract infections, pneumonia and decubitus ulcers) were considered as our secondary outcome.

Results

Among 40 545 newly admitted nursing home residents (mean age 86.8 years), the incidence rate of unplanned hospitalization ranged from 53.9 per 100 person-years among residents with tertiary education up to 55.1 among those with primary education. After adjusting for relevant confounders, we observed no meaningful difference in the risk of unplanned hospitalization according to the education level of nursing home residents (IRR for tertiary vs. primary education: 0.96, 95% CI 0.92–1.00) or to their level of income (IRR for highest vs. lowest quartile of income: 0.98, 0.95–1.02). There were also no differences in the cumulative length of hospital stays or in the risk of experiencing unplanned hospitalizations for potentially avoidable causes.

Conclusions

In sum, in this large cohort of newly admitted nursing home residents, we found no evidence of socioeconomic inequalities in the risk of unplanned hospitalization.
Lifetime costs and lifetime net public expenditures of smoking
Authors: Rasmussen Susanne R , Søgaard Jes , Kjellberg Jakob
Published: October 2020

Background

Current estimates of lifetime costs of smoking are largely based on model analyses using etiologic fractions for a variety of diseases or Markov chain models. Direct estimation studies based on individual data for health costs by smoking status over a lifetime are non-existent.

Methods

We estimated lifetime costs in a societal perspective of 18-year-old daily-smokers (continuing smoking throughout adult life) and never-smokers in Denmark, as well as lifetime public expenditures in the two groups. Main outcomes were lifetime net public expenditures and lifetime health costs according to OECD definitions and lifetime earned incomes. Estimates of these outcomes were based on registries containing individual-level data. Confounder-adjusted differences between daily-smokers and never-smokers were interpreted as smoking-attributable lifetime public expenditures and costs.

Results

The net lifetime public expenditure is, on average, €20 520 higher for male 18-year-old daily-smokers than for never-smokers, but €9771 lower, for female daily-smokers compared with never-smokers. In male 18-year-old daily-smokers, average lifetime health costs are €9921 higher and average lifetime earned incomes are €91 159 lower than for never-smokers. The corresponding figures are €5849 higher and €23 928 lower, respectively, for women.

Conclusion

18-year-old male daily-smokers are net public spenders over their lifetime compared with never-smokers, while the opposite applies for women. In Denmark, smoking is associated with higher lifetime health costs for society and losses in earned incomes—both for men and women.
Splenic-vasculature involvement is associated with poor prognosis in resected distal pancreatic cancer
Authors: Yin Feng , Saad Mohammed , Lin Jingmei , Jackson Christopher R , Ren Bing , Lawson Cynthia , Karamchandani Dipti M , Bernabeu Belen Quereda , Jiang Wei , Dhir Teena , Zheng Richard , Schultz Christopher W , Zhang Dongwei , Thomas Courtney L , Zhang Xuchen , Lai Jinping , Schild Michael , Zhang Xuefeng , Xie Hao , Liu Xiuli
Published: October 2020

Background

Distal pancreatic carcinoma is one of the most lethal cancers largely due to its high incidence of distant metastasis. This study aims to assess the prognostic value of splenic-vasculature involvement in resected distal pancreatic carcinoma.

Methods

In this retrospective study, we collected the clinicopathologic information of 454 patients with pancreatic cancer and performed univariate and multivariate analyses to identify factors associated with progression-free survival (PFS) and overall survival (OS), with an emphasis on the prognostic value of splenic-artery and -vein involvement.

Results

Univariate analysis revealed that larger tumor size, non-intraductal papillary mucinous neoplasm (non-IPMN)-associated adenocarcinoma, poor differentiation, stage pT3, nodal metastasis, lymphovascular invasion, perineural invasion, and pathologic and radiographic evidence of splenic-vein invasion were significantly associated with shorter PFS and OS (all P < 0.05). Multivariate analysis confirmed non-IPMN-associated adenocarcinoma, stage pT3, stage pN1–2, and post-operative adjuvant chemotherapy as independent risk factors for both PFS and OS, and larger tumor size and radiographic evidence of splenic-artery invasion as predictors of PFS only.

Conclusion

Guidelines should be developed for a uniform approach with regard to the examination and reporting of the status of the splenic vasculature when dealing with distal-pancreatic-cancer specimens.
Records of the Laschamps geomagnetic polarity excursion from Black Sea sediments: magnetite versus greigite, discrete sample versus U-channel data
Authors: Nowaczyk Norbert R , Liu Jiabo , Arz Helge W
Published: October 2020

Magnetostratigraphic investigation of sediment cores from two different water depths in the SE Black Sea based on discrete samples, and parallel U-channels in one of the cores, yielded high-resolution records of geomagnetic field variations from the past about 68 ka. Age constrains are provided by three tephra layers of known age, accelerator mass spectrometry 14C dating, and by tuning element ratios obtained from X-ray fluorescence scanning to the oxygen isotope record from Greenland ice cores. Sedimentation rates vary from a minimum of ∼5 cm ka−1 in the Holocene to a maximum of ∼50 cm ka−1 in glacial marine isotope stage 4. Completely reversed inclinations and declinations as well as pronounced lows in relative palaeointensity around 41 ka provide evidence for the Laschamps geomagnetic polarity excursion. In one of the investigated cores also a fragmentary record of the Mono Lake excursion at 34.5 ka could be revealed. However, the palaeomagnetic records are more or less affected by greigite, a diagenetically formed magnetic iron sulphide. By definition of an exclusion criterion based on the ratio of saturation magnetization over volume susceptibility, greigite-bearing samples were removed from the palaeomagnetic data. Thus, only 25–55 per cent of the samples were left in the palaeomagnetic records obtained from sediments from the shallower coring site. The palaeomagnetic record from the deeper site, based on both discrete samples and U-channels, is much less affected by greigite. The comparison of palaeomagnetic data shows that the major features of the Laschamps polarity excursion were similarly recovered by both sampling techniques. However, several intervals had to be removed from the U-channel record due to the presence of greigite, carrying anomalous directions. By comparison to discrete sample data, also some directional artefacts in the U-channel record, caused by low-pass filtering of the broad magnetometer response functions, averaging across fast directional and large amplitude changes, can be observed. Therefore, high-resolution sampling with discrete samples should be the preferred technique when fast geomagnetic field variations, such as reversals and excursions, shall be studied from sedimentary records in the very detail.
High-coercivity magnetic minerals in archaeological baked clay and bricks
Authors: Kosterov Andrei , Kovacheva Mary , Kostadinova-Avramova Maria , Minaev Pavel , Salnaia Natalia , Surovitskii Leonid , Yanson Svetlana , Sergienko Elena , Kharitonskii Petr
Published: October 2020

The thorough understanding of magnetic mineralogy is a prerequisite of any successful palaeomagnetic or archaeomagnetic study. Magnetic minerals in archaeological ceramics and baked clay may be inherited from the parent material or, more frequently, formed during the firing process. The resulting magnetic mineralogy may be complex, including ferrimagnetic phases not commonly encountered in rocks. Towards this end, we carried out a detailed rock magnetic study on a representative collection of archaeological ceramics (baked clay from combustion structures and bricks) from Bulgaria and Russia. Experiments included measurement of isothermal remanence acquisition and demagnetization as a function of temperature between 20 and >600 °C. For selected samples, low-temperature measurements of saturation remanence and initial magnetic susceptibility between 1.8 and 300 K have been carried out. All studied samples contain a magnetically soft mineral identified as maghemite probably substituted by Ti, Mn and/or Al. Stoichiometric magnetite has never been observed, as evidenced by the absence of the Verwey phase transition. In addition, one or two magnetically hard mineral phases have been detected, differing sharply in their respective unblocking temperatures. One of these unblocking between 540 and 620 °C is believed to be substituted hematite. Another phase unblocks at much lower temperatures, between 140 and 240 °C, and its magnetic properties correspond to an enigmatic high coercivity, stable, low-unblocking temperature (HCSLT) phase reported earlier. In a few samples, high- and low unblocking temperature, magnetically hard phases appear to coexist; in the others, the HCSLT phase is the only magnetically hard mineral present.
Parenting style as longitudinal predictor of adolescents’ health behaviors in Lebanon
Authors: Hayek Joyce , Tueni Maya , Schneider Francine , de Vries Hein
Published: October 2020

This prospective study aimed to examine how parenting style relates to health behaviors and body mass index of Lebanese adolescents while checking for interactive effect of child characteristics (age and gender). About 341 students from private and public schools in Mount Lebanon and Beirut area, aged between 16 and 18 years, completed a self-administered survey assessing socio-demographics, parenting styles and health behaviors. Adolescents were surveyed at two time points, six months apart. Anthropometric measurements were also taken. Authoritative parenting was associated with better outcomes compared to the neglectful style. Adolescents raised with an authoritative style had higher adherence to the Mediterranean diet and lower consumption of alcohol intake. Parenting style was a significant predictor of eating behavior and alcohol intake of Lebanese adolescent. Interventions aiming at improving health behaviors should also encompass healthy parenting style strategies.
Identifying assessment scales for food web criteria in the NE Atlantic: implications for the Marine Strategy Framework Directive
Authors: Machado I , Teixeira C M , Costa J L , Cabral H
Published: October 2020

The implementation of food web criteria in the Marine Strategy Framework Directive context faces several difficulties, namely the lack of data for relevant taxa, the absence of operational indicators, and spatially and temporally limited datasets. This work aims to identify ecologically relevant scales in the Celtic Seas (CS) and the Bay of Biscay and Iberian Coast (BBIC). Four food web criteria—mean trophic level (MTL), mean trophic level with cut-offs (MTL_3.25 and MTL_4), large fish indicator (LFI) and mean abundance across trophic guild (MATG)—were assessed using groundfish data and tested using generalized additive models, for six spatial scales and four temporal scales. In both subregions, MTL required yearly and locally defined assessment scales. As for MTL_3.25, it improved significantly when downsizing spatial scales but was temporally consistent. In the CS, locally defined scales and yearly data explained MTL_4 and LFI. While in BBIC, MTL_4 and LFI patterns were defined spatially by region and depth and temporally by year. MATG variability was unaffected by scales. Using the scales identified, food web criteriawere assessed for the Portuguese continental waters. Criteria failed to achieve Good Environmental Status in areas of the Southwest and South of Portugal. Although downsizing scales revealed that criteria were below the threshold at local/regional level, differences in classification are expected to be limited if spatial assessments are aggregated.
Early-childhood cytomegalovirus infection and children’s neurocognitive development
Authors: Lee Samantha M , Mitchell Ruth , Knight Julia A , Mazzulli Tony , Relton Caroline , Khodayari Moez Elham , Hung Rayjean J
Published: October 2020

Background

Despite a clear association seen in congenitally infected children, the effect of postnatal cytomegalovirus (CMV) infection during early childhood on cognitive development has not yet been determined.

Methods

CMV-infection status was obtained based on serological measurements when children were 7 years old. Using population-based longitudinal data, we employed multivariate Poisson regression with a robust variance estimator to characterize the relationship between childhood CMV infection and adverse neurocognitive outcomes in children. Suboptimal neurocognitive outcomes were compared between CMV-positive and CMV-negative children using various cognitive assessments from 8 to 15 years of age. Children were evaluated on the cognitive domains of language, reading, memory and general intelligence, with a suboptimal score being >2 standard deviations lower than the mean score. Approximate Bayes factor (ABF) analysis was used to determine the level of evidence for the observed associations.

Results

With adjustment for potential confounders, we observed that early-childhood CMV infection was associated with suboptimal total intelligence quotient (IQ) at 8 years of age [incidence-rate ratio (IRR) = 2.50, 95% confidence interval (CI) 1.35–4.62, ABF = 0.08], but not with suboptimal total IQ at 15 years of age (IRR = 0.97, 95% CI 0.43–2.19, ABF = 1.68). Suboptimal attentional control at 8 years (IRR = 1.74, 95% CI 1.13–2.68, ABF = 0.18) and reading comprehension at 9 years (IRR = 1.93, 95% CI 1.12–3.33, ABF = 0.24) were also associated with CMV infection. ABF analysis provided strong evidence for the association between CMV infection and total IQ at 8 years, and only anecdotal evidence for attentional control at 8 years and reading comprehension at 9 years. All other cognitive measures assessed were not associated with CMV infection.

Conclusion

In this large-scale prospective cohort, we observed some evidence for adverse neurocognitive effects of postnatal CMV infection on general intelligence during early childhood, although not with lasting effect. If confirmed, these results could support the implementation of preventative measures to combat postnatal CMV infection.
One-Bipolar Topologically Slice Knots and Primary Decomposition
Authors: Kim Min Hoon , Kim Se-Goo , Kim Taehee
Published: October 2020

Let $\{{\mathcal{T}}_n\}$ be the bipolar filtration of the smooth concordance group of topologically slice knots, which was introduced by Cochran et al. It is known that for each $n\ne 1$ the group ${\mathcal{T}}_n/{\mathcal{T}}_{n+1}$ has infinite rank and ${\mathcal{T}}_1/{\mathcal{T}}_2$ has positive rank. In this paper, we show that ${\mathcal{T}}_1/{\mathcal{T}}_2$ also has infinite rank. Moreover, we prove that there exist infinitely many Alexander polynomials $p(t)$ such that there exist infinitely many knots in ${\mathcal{T}}_1$ with Alexander polynomial $p(t)$ whose nontrivial linear combinations are not concordant to any knot with Alexander polynomial coprime to $p(t)$, even modulo ${\mathcal{T}}_2$. This extends the recent result of Cha on the primary decomposition of ${\mathcal{T}}_n/{\mathcal{T}}_{n+1}$ for all $n\ge 2$ to the case $n=1$. To prove our theorem, we show that the surgery manifolds of satellite links of $\nu ^+$-equivalent knots with the same pattern link have the same Ozsváth–Szabó $d$-invariants, which is of independent interest. As another application, for each $g\ge 1$, we give a topologically slice knot of concordance genus $g$ that is $\nu ^+$-equivalent to the unknot.
Population pharmacokinetics and dosing optimization of azlocillin in neonates with early-onset sepsis: a real-world study
Authors: Wu Yue-E , Wang Tao , Yang Hua-Liang , Tang Bo-Hao , Kong Li , Li Xin , Gao Qi , Li Xue , Yao Bu-Fan , Shi Hai-Yan , Huang Xin , Wang Wen-Qi , Jacqz-Aigrain Evelyne , Allegaert Karel , van den Anker John , Tian Xiu-Ying , Zhao Wei
Published: October 2020

Objectives

Nowadays, real-world data can be used to improve currently available dosing guidelines and to support regulatory approval of drugs for use in neonates by overcoming practical and ethical hurdles. This proof-of-concept study aimed to assess the population pharmacokinetics of azlocillin in neonates using real-world data, to make subsequent dose recommendations and to test these in neonates with early-onset sepsis (EOS).

Methods

This prospective, open-label, investigator-initiated study of azlocillin in neonates with EOS was conducted using an adaptive two-step design. First, a maturational pharmacokinetic-pharmacodynamic model of azlocillin was developed, using an empirical dosing regimen combined with opportunistic samples resulting from waste material. Second, a Phase II clinical trial (ClinicalTrials.gov: NCT03932123) of this newly developed model-based dosing regimen of azlocillin was conducted to assure optimized target attainment [free drug concentration above MIC during 70% of the dosing interval (‘70% fT>MIC’)] and to investigate the tolerance and safety in neonates.

Results

A one-compartment model with first-order elimination, using 167 azlocillin concentrations from 95 neonates (31.7–41.6 weeks postmenstrual age), incorporating current weight and renal maturation, fitted the data best. For the second step, 45 neonates (30.3–41.3 weeks postmenstrual age) were subsequently included to investigate target attainment, tolerance and safety of the pharmacokinetic-pharmacodynamic model-based dose regimen (100 mg/kg q8h). Forty-three (95.6%) neonates reached their pharmacokinetic target and only two neonates experienced adverse events (feeding intolerance and abnormal liver function), possibly related to azlocillin.

Conclusions

Target attainment, tolerance and safety of azlocillin was shown in neonates with EOS using a pharmacokinetic-pharmacodynamic model developed with real-world data.
The urbanising force of global warming: the role of climate change in the spatial distribution of population
Authors: Castells-Quintana David , Krause Melanie , McDermott Thomas K J
Published: October 2020

We study the relationship between changes in weather patterns and the spatial distribution of population and economic activity within countries. Our unique global dataset combines climatic and census data for the period 1950–2015 with satellite data on built-up areas, and light intensity at night for the 1990–2015 periods. We establish a global non-linear effect of climate on urbanisation. In particular, we find that deteriorating climatic conditions are associated with more urbanisation. This happens across the whole urban structure, with urbanisation increasing in both smaller and larger cities. But, we also find that weather variation can alter the national urban structure, including the pattern of urban concentration, as well as the size, density and spatial structure of large cities.
Prevalence of Leishmania major Yakimoff and Schokhor (Kinetoplastida: Trypanosomatidae) in Sandflies in Iran: A Systematic Review and Meta-Analysis
Authors: Shoraka Hamid Reza , Taheri Soodejani Moslem , Allah Kalteh Ehsan , Chegeni Maryam , Mahmudimanesh Marzieh , Sofizadeh Aioub
Published: October 2020

Cutaneous leishmaniasis is an important parasitic and vector-borne disease in Iran and can be transmitted to humans and animals through bites of infected female sand flies. The present study aimed to determine the pooled prevalence of Leishmania major in sand flies in Iran. A systematic review and meta-analysis was performed in the present study, so that databases, namely PubMed, Web of Sciences, Science Direct, ProQuest, Embase, Cochrane Reviews, and Scopus as well as IranDoc, SID, Elmnet, and Magiran were searched for finding Persian articles. Inclusion criteria of study contained the study in Iran and investigation of L. major parasite in sand flies. The quality of studies was examined by Joanna Briggs Institute Critical Appraisal Checklist for studies that reported prevalence data; and the data were analyzed by Stata 14 software. In total, 42 studies were evaluated, all of which had investigated the infection of Phlebotomus papatasi Scopoli (Diptera: Psychodidae). The infection of Phlebotomus caucasicus group was investigated in 13 studies, Phlebotomus ansarii Lewis in four studies, Phlebotomus salehi Mesghali and Rashti in five studies, and the infection of other species of sandflies in seven studies. According to the meta-analysis, the pooled prevalence of Ph. papatasi, Ph. caucasicus group, Ph. salehi, and Ph. ansarii were equal to 2.4, 6.2, 1.6, and 9.2%, respectively, with 95% confidence interval.

According to reports of different rates of sand fly infection in different regions, all studies should have certain and standard forms and formats to determine the pooled prevalence of sand fly infection.
Two subgroups of receptor-like kinases promote early compatible pollen responses in the Arabidopsis thaliana pistil
Authors: Lee Hyun Kyung , Goring Daphne R
Published: October 2020

In flowering plants, cell–cell communication between the compatible pollen grain/growing pollen tube and the pistil is an essential component for successful sexual reproduction. In Arabidopsis thaliana, the later stages of this dialogue are mediated by several peptide ligands and receptors that guide pollen tubes to the ovules for the release of sperm cells. Despite a detailed understanding of these processes, a key gap remains regarding the nature of the regulators that function at the earlier stages which are essential steps leading to fertilization. Here, we report on new functions for A. thaliana Receptor-Like Kinase (RLK) genes belonging to the LRR-II and LRR-VIII-2 RLK subgroups in the female reproductive tract to regulate compatible pollen hydration and the early stages of pollen tube growth. Mutant pistils for the A. thaliana RKF1 gene cluster were observed to support reduced wild-type pollen hydration and, when combined with the SERK1 and SERK3/BAK1 mutations, reduced pollen tube travel distances occurred. As these mutant pistils displayed a wild-type morphology, we propose that the observed altered compatible pollen responses result from an impaired pollen–pistil dialogue at these early stages.
How Should We Talk About Climate Change and Migration?
Authors: Morrissey James
Published: October 2020

This paper is a response Ferris (2020), specifically to the call for coalescence around a single term by which to talk about people migrating in response to climate change. While sympathetic to the imperative behind Ferris’ (2020) call, my overall argument is to reject this proposal. Instead I argue for less of focus on what we call people migrating in response to climate change, and more of a focus on how we talk about them. To justify this, I argue that a single term is inherently reductive and likely to play upon anti-immigrant sentiment due to the need to portray ‘migration as a problem’. At best this will result in a policy focus with limited capacity to address the challenge of migration in a context of climate change. At worst it will drive a policy response that is overtly counter-productive. As an alternative, I propose embracing a multitude of discourses, informed by principals that I argue will drive a humane climate agenda, and allow for a flexible approach that can account for the variety of concerns at the nexus of climate change and human migration.
The hyper-stable disc of UGC 8839
Authors: Young Jason E , Eleazer Miriam
Published: October 2020

The low surface brightness spiral UGC 8839 is nearly devoid of star formation aside from a large $\rm H\,{\small II}$ region complex located in the extreme outer disc. In order to understand the origin and nature of this complex, we compare new $\rm H\,\alpha$ and archival broad-band images of UGC 8839 to similar data for four other spiral galaxies. We conclude that the extreme off-axis star formation in UGC 8839 is likely due to a hyper-stable disc that is dark matter dominated at all radii, with the Toomre parameter reaching a minimum only in the extreme outer disc. Using analysis strategies designed to be particularly insensitive to the pitfalls of low surface brightness objects and small number statistics, we determine that the presence of this complex in UGC 8839 is not exceptional when the $\rm H\,{\small II}$ region luminosity function is modelled by a power law, suggesting that it is a native structure and not a merging satellite. However, we find that the entire population of $\rm H\,{\small II}$ regions in UGC 8839 shows a preference for larger galactocentric radii when compared to $\rm H\,{\small II}$ regions in the other galaxies in our sample. UGC 8839 dramatically highlights the relationship between the baryonic/dark matter ratio and disc stability. A three-body interaction, similar to a scaled-down version of the interaction suspected to be responsible for Malin 1, is consistent with the extreme outer disc star formation that we see in the extended disc of UGC 8839.
The specific star formation rate function at different mass scales and quenching: a comparison between cosmological models and SDSS
Authors: Katsianis Antonios , Xu Haojie , Yang Xiaohu , Luo Yu , Cui Weiguang , Davé Romeel , Lagos Claudia Del P , Zheng Xianzhong , Zhao Ping
Published: October 2020

We present the eddington bias corrected specific star formation rate function (sSFRF) at different stellar mass scales from a sub-sample of the Sloan Digital Sky Survey Data Release DR7 (SDSS), which is considered complete both in terms of stellar mass (M⋆) and star formation rate (SFR). The above enable us to study qualitatively and quantitatively quenching, the distribution of passive/star-forming galaxies and perform comparisons with the predictions from state-of-the-art cosmological models, within the same M⋆ and SFR limits. We find that at the low-mass end (${M_{\star }} = 10^{9.5}\!-\!10^{10} \, {\rm M_{\odot }}$) the sSFRF is mostly dominated by star-forming objects. However, moving to the two more massive bins (${M_{\star }} = 10^{10}\!-\!10^{10.5} \, {\rm M_{\odot }}$ and ${M_{\star }} = 10^{10.5}\!-\!10^{11} \, {\rm M_{\odot }}$) a bi-modality with two peaks emerges. One peak represents the star-forming population, while the other describes a rising passive population. The bi-modal form of the sSFRFs is not reproduced by a range of cosmological simulations (e.g. Illustris, EAGLE, Mufasa, and IllustrisTNG) which instead generate mostly the star-forming population, while a bi-modality emerges in others (e.g. L-Galaxies, Shark, and Simba). Our findings reflect the need for the employed quenching schemes in state-of-the-art models to be reconsidered, involving prescriptions that allow ‘quenched galaxies’ to retain a small level of SF activity (sSFR = ${\rm 10^{-11} \, }$–${\rm 10^{-12} \, {\rm yr^{-1}}}$) and generate an adequate passive population/bi-modality even at intermediate masses (${M_{\star }} = 10^{10}\!-\!10^{10.5} \, {\rm M_{\odot }}$).
An efficient hybrid method to produce high-resolution large-volume dark matter simulations for semi-analytic models of reionization
Authors: Qiu Yisheng , Mutch Simon J , Elahi Pascal J , Poulton Rhys J J , Power Chris , Wyithe J Stuart B
Published: October 2020

Resolving faint galaxies in large volumes is critical for accurate cosmic reionization simulations. While less demanding than hydrodynamical simulations, semi-analytic reionization models still require very large N-body simulations in order to resolve the atomic cooling limit across the whole reionization history within box sizes ${\gtrsim}100 \, h^{-1}\, \rm Mpc$. To facilitate this, we extend the mass resolution of N-body simulations using a Monte Carlo algorithm. We also propose a method to evolve positions of Monte Carlo haloes, which can be an input for semi-analytic reionization models. To illustrate, we present an extended halo catalogue that reaches a mass resolution of $M_\text{halo} = 3.2 \times 10^7 \, h^{-1} \, \text{M}_\odot$ in a $105 \, h^{-1}\, \rm Mpc$ box, equivalent to an N-body simulation with ∼68003 particles. The resulting halo mass function agrees with smaller volume N-body simulations with higher resolution. Our results also produce consistent two-point correlation functions with analytic halo bias predictions. The extended halo catalogues are applied to the meraxes semi-analytic reionization model, which improves the predictions on stellar mass functions, star formation rate densities, and volume-weighted neutral fractions. Comparison of high-resolution large-volume simulations with both small-volume and low-resolution simulations confirms that both low-resolution and small-volume simulations lead to reionization ending too rapidly. Lingering discrepancies between the star formation rate functions predicted with and without our extensions can be traced to the uncertain contribution of satellite galaxies.
Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum
Authors: Fagnoni Nicolas , de Lera Acedo Eloy , DeBoer David R , Abdurashidova Zara , Aguirre James E , Alexander Paul , Ali Zaki S , Balfour Yanga , Beardsley Adam P , Bernardi Gianni , Billings Tashalee S , Bowman Judd D , Bradley Richard F , Bull Phil , Burba Jacob , Carilli Chris L , Cheng Carina , Dexter Matt , Dillon Joshua S , Ewall-Wice Aaron , Fritz Randall , Furlanetto Steve R , Gale-Sides Kingsley , Glendenning Brian , Gorthi Deepthi , Greig Bradley , Grobbelaar Jasper , Halday Ziyaad , Hazelton Bryna J , Hewitt Jacqueline N , Hickish Jack , Jacobs Daniel C , Josaitis Alec , Julius Austin , Kern Nicholas S , Kerrigan Joshua , Kim Honggeun , Kittiwisit Piyanat , Kohn Saul A , Kolopanis Matthew , Lanman Adam , Plante Paul La , Lekalake Telalo , Liu Adrian , MacMahon David , Malan Lourence , Malgas Cresshim , Maree Matthys , Martinot Zachary E , Matsetela Eunice , Mena Parra Juan , Mesinger Andrei , Molewa Mathakane , Morales Miguel F , Mosiane Tshegofalang , Neben Abraham R , Nikolic Bojan , Parsons Aaron R , Patra Nipanjana , Pieterse Samantha , Pober Jonathan C , Razavi-Ghods Nima , Robnett James , Rosie Kathryn , Sims Peter , Smith Craig , Syce Angelo , Thyagarajan Nithyanandan , Williams Peter K G , Zheng Haoxuan
Published: October 2020

The detection of the Epoch of Reionization (EoR) delay power spectrum using a ‘foreground avoidance method’ highly depends on the instrument chromaticity. The systematic effects induced by the radio telescope spread the foreground signal in the delay domain, which contaminates the EoR window theoretically observable. Applied to the Hydrogen Epoch of Reionization Array (HERA), this paper combines detailed electromagnetic and electrical simulations in order to model the chromatic effects of the instrument, and quantify its frequency and time responses. In particular, the effects of the analogue receiver, transmission cables, and mutual coupling are included. These simulations are able to accurately predict the intensity of the reflections occurring in the 150-m cable which links the antenna to the backend. They also show that electromagnetic waves can propagate from one dish to another one through large sections of the array due to mutual coupling. The simulated system time response is attenuated by a factor 104 after a characteristic delay which depends on the size of the array and on the antenna position. Ultimately, the system response is attenuated by a factor 105 after 1400 ns because of the reflections in the cable, which corresponds to characterizable k∥-modes above 0.7 $h\,\,\rm {Mpc}^{-1}$ at 150 MHz. Thus, this new study shows that the detection of the EoR signal with HERA Phase I will be more challenging than expected. On the other hand, it improves our understanding of the telescope, which is essential to mitigate the instrument chromaticity.
Determining the systemic redshift of Lyman α emitters with neural networks and improving the measured large-scale clustering
Authors: Gurung-López Siddhartha , Saito Shun , Baugh Carlton M , Bonoli Silvia , Lacey Cedric G , Orsi Álvaro A
Published: October 2020

We explore how to mitigate the clustering distortions in Lyman α emitter (LAE) samples caused by the misidentification of the Lyman α ($\rm {Ly}\,\alpha$) wavelength in their $\rm {Ly}\,\alpha$ line profiles. We use the $\rm {Ly}\,\alpha$ line profiles from our previous LAE theoretical model that includes radiative transfer in the interstellar and intergalactic mediums. We introduce a novel approach to measure the systemic redshift of LAEs from their $\rm {Ly}\,\alpha$ line using neural networks. In detail, we assume that for a fraction of the whole LAE population their systemic redshift is determined precisely through other spectral features. We then use this subset to train a neural network that predicts the $\rm {Ly}\,\alpha$ wavelength given an $\rm {Ly}\,\alpha$ line profile. We test two different training sets: (i) the LAEs are selected homogeneously and (ii) only the brightest LAE is selected. In comparison with previous approaches in the literature, our methodology improves significantly the accuracy in determining the $\rm {Ly}\,\alpha$ wavelength. In fact, after applying our algorithm in ideal $\rm {Ly}\,\alpha$ line profiles, we recover the clustering unperturbed down to $1\, {\rm cMpc}\, h^{-1}$. Then, we test the performance of our methodology in realistic $\rm {Ly}\,\alpha$ line profiles by downgrading their quality. The machine learning technique using the uniform sampling works well even if the $\rm {Ly}\,\alpha$ line profile quality is decreased considerably. We conclude that LAE surveys such as HETDEX would benefit from determining with high accuracy the systemic redshift of a subpopulation and applying our methodology to estimate the systemic redshift of the rest of the galaxy sample.
Detailed studies of IPHAS sources - I. The disrupted late bipolar IPHASX J193718.6+202102
Authors: Sabin L , Guerrero M A , Zavala S , Toalá J A , Ramos-Larios G , Gómez-Llanos V
Published: October 2020

We present a detailed analysis of the new planetary nebula (PN) IPHASX J193718.6+202102 using deep imaging and intermediate- and high resolution spectroscopy that are interpreted through morpho-kinematic and photoionisation modelling. The physical structure of the nebula consists of a fragmented torus and an extremely faint orthogonal bipolar outflow, contrary to the pinched waist PN morphology suggested by its optical image. Our kinematic analysis indicates that the torus is expanding at 25±5 km s−1 and is gradually breaking up. At an estimated distance of 7.1$_{-0.3}^{+0.8}$ kpc, the corresponding kinematic age of ∼26000 years is consistent with a faint and disintegrating PN. The intermediate-resolution spectra reveal an excited PN with chemical abundances typical of Type II PNe. Based on the latter we also estimate an initial mass for the progenitor in the range 2–3 M⊙ and a central star (CSPN) mass MCSPN ∼0.61 M⊙. The Spitzer MIPS 24 μm emission that closely follows the fragmented torus could be attributed to the emission of [O iv] at 25.9 μm rather than to dust emission. All the results coherently point towards an evolved moderately massive bipolar Type II PN on the brink of dissolving into the interstellar medium.
Metallicity and X-ray luminosity variations in NGC 922
Authors: Kouroumpatzakis K , Zezas A , Wolter A , Fruscione A , Anastasopoulou K , Prestwich A
Published: October 2020

We present a systematic study of the metallicity variations within the collisional ring galaxy NGC 922 based on long-slit optical spectroscopic observations. We find a metallicity difference between star-forming regions in the bulge and the ring, with metallicities ranging from almost solar to significantly sub-solar ($\rm {[12+\log (O/H)]\sim 8.2}$). We detect $\rm{He\,{\small I}}$ emission in all the studied regions of the bulge and the ring, indicating ionization from massive stars associated with recent (<10 Myr) star formation, in agreement with the presence of very young star clusters. We find an anticorrelation between the X-ray luminosity and metallicity of the sub-galactic regions of NGC 922. The different regions have similar stellar population ages, leaving metallicity as the main driver of the anticorrelation. The dependence of the X-ray emission of the different regions in NGC 922 on metallicity is in agreement with similar studies of the integrated X-ray output of galaxies and predictions from X-ray binary population models.
Combining ILC and moment expansion techniques for extracting average-sky signals and CMB anisotropies
Authors: Rotti Aditya , Chluba Jens
Published: October 2020

The method of weighted addition of multi-frequency maps, more commonly referred to as Internal Linear Combination (ILC), has been extensively employed in the measurement of cosmic microwave background (CMB) anisotropies and its secondaries along with similar application in 21cm data analysis. Here we argue and demonstrate that ILC methods can also be applied to data from absolutely-calibrated CMB experiments to extract average-sky signals in addition to the conventional CMB anisotropies. The performance of the simple ILC method is, however, limited, but can be significantly improved by adding constraints informed by physics and existing empirical information. In recent work, a moment description has been introduced as a technique of carrying out high precision modeling of foregrounds in the presence of inevitable averaging effects. We combine these two approaches to construct a heavily constrained form of the ILC, dubbed MILC, which can be used to recover tiny monopolar spectral distortion signals in the presence of realistic foregrounds and instrumental noise. This is a first demonstration for measurements of the monopolar and anisotropic spectral distortion signals using ILC and extended moment methods. We also show that CMB anisotropy measurements can be improved, reducing foreground biases and signal uncertainties when using the MILC. While here we focus on CMB spectral distortions, the scope extends to the 21cm monopole signal and B-mode analysis. We briefly discuss augmentations that need further study to reach the full potential of the method.
Evaluating hydrodynamical simulations with green valley galaxies
Authors: Angthopo J , Negri A , Ferreras I , de la Rosa I G , Dalla Vecchia C , Pillepich A
Published: October 2020

We test cosmological hydrodynamical simulations of galaxy formation regarding the properties of the blue cloud (BC), green valley (GV), and red sequence (RS), as measured on the 4000Å break strength versus stellar mass plane at z = 0.1. We analyse the RefL0100N1504 run of EAGLE and the TNG100 run of IllustrisTNG project, by comparing them with the Sloan Digital Sky Survey (SDSS), while taking into account selection bias. Our analysis focuses on the GV, within stellar mass $\log \, \mathrm{{\it M}_\star /M_{\odot }} \simeq 10\!-\!11$, selected from the bimodal distribution of galaxies on the Dn(4000) versus stellar mass plane, following Angthopo et al. methodology. Both simulations match the fraction of AGN in the GV. However, they overproduce quiescent GV galaxies with respect to observations, with IllustrisTNG yielding a higher fraction of quiescent GV galaxies than EAGLE. In both, GV galaxies have older luminosity-weighted ages with respect to the SDSS, while a better match is found for mass-weighted ages. We find EAGLE GV galaxies quench their star formation early, but undergo later episodes of star formation, matching observations. In contrast, IllustrisTNG GV galaxies have a more extended star formation history, and quench more effectively at later cosmic times, producing the excess of quenched galaxies in GV compared with SDSS, based on the 4000Å break strength. These results suggest the AGN feedback subgrid physics, more specifically, the threshold halo mass for black hole input and the black hole seed mass, could be the primary cause of the overproduction of quiescent galaxies found with respect to the observational constraints.
Asymmetron: a toolkit for the identification of strand asymmetry patterns in biological sequences
Authors: Georgakopoulos-Soares Ilias , Mouratidis Ioannis , Parada Guillermo E , Matharu Navneet , Hemberg Martin , Ahituv Nadav
Published: October 2020

DNA strand asymmetries can have a major effect on several biological functions, including replication, transcription and transcription factor binding. As such, DNA strand asymmetries and mutational strand bias can provide information about biological function. However, a versatile tool to explore this does not exist. Here, we present Asymmetron, a user-friendly computational tool that performs statistical analysis and visualizations for the evaluation of strand asymmetries. Asymmetron takes as input DNA features provided with strand annotation and outputs strand asymmetries for consecutive occurrences of a single DNA feature or between pairs of features. We illustrate the use of Asymmetron by identifying transcriptional and replicative strand asymmetries of germline structural variant breakpoints. We also show that the orientation of the binding sites of 45% of human transcription factors analyzed have a significant DNA strand bias in transcribed regions, that is also corroborated in ChIP-seq analyses, and is likely associated with transcription. In summary, we provide a novel tool to assess DNA strand asymmetries and show how it can be used to derive new insights across a variety of biological disciplines.
Viral RNA recognition by LGP2 and MDA5, and activation of signaling through step-by-step conformational changes
Authors: Duic Ivana , Tadakuma Hisashi , Harada Yoshie , Yamaue Ryo , Deguchi Katashi , Suzuki Yuki , Yoshimura Shige H , Kato Hiroki , Takeyasu Kunio , Fujita Takashi
Published: October 2020

Cytoplasmic RIG-I-like receptor (RLR) proteins in mammalian cells recognize viral RNA and initiate an antiviral response that results in IFN-β induction. Melanoma differentiation-associated protein 5 (MDA5) forms fibers along viral dsRNA and propagates an antiviral response via a signaling domain, the tandem CARD. The most enigmatic RLR, laboratory of genetics and physiology (LGP2), lacks the signaling domain but functions in viral sensing through cooperation with MDA5. However, it remains unclear how LGP2 coordinates fiber formation and subsequent MDA5 activation. We utilized biochemical and biophysical approaches to observe fiber formation and the conformation of MDA5. LGP2 facilitated MDA5 fiber assembly. LGP2 was incorporated into the fibers with an average inter-molecular distance of 32 nm, suggesting the formation of hetero-oligomers with MDA5. Furthermore, limited protease digestion revealed that LGP2 induces significant conformational changes on MDA5, promoting exposure of its CARDs. Although the fibers were efficiently dissociated by ATP hydrolysis, MDA5 maintained its active conformation to participate in downstream signaling. Our study demonstrated the coordinated actions of LGP2 and MDA5, where LGP2 acts as an MDA5 nucleator and requisite partner in the conversion of MDA5 to an active conformation. We revealed a mechanistic basis for LGP2-mediated regulation of MDA5 antiviral innate immune responses.