bluuebunny/crossref_metadata_2025 huggingface dataset:
Supercilious monk at Kiṭāgiri
Authors: Handy Christopher
Published: December 2019

This paper focuses on the concepts of etiquette and politeness within a genre of Buddhist texts known as “vinaya”, or monastic law. These texts were created for the purpose of regulating behavior within the monastic institution. While they are often described by the tradition as a set of ethical principles, the content of monastic law codes also includes many things that would be better categorized as examples of normative protocol, encompassing mundane, everyday social situations that promote harmony between the monastic institution and its economic patrons. I argue here that a distinct concept of politeness can be gleaned from the narratives in these texts, despite the lack of such a category in the tradition’s own account of itself. To illustrate this point, I analyze several stories concerned with the proper deportment of monastics, demonstrating that the standards for monastic behavior were sometimes at odds with the expectations of the lay communities that supported them.
Reflexive pronouns in the Lindisfarne glosses
Authors: van Gelderen Elly
Published: December 2019

Old English uses personal pronouns, demonstratives, and limited null subject for reference to previously mentioned nouns. It uses personal pronouns reflexively and pronouns modified by ‘self’ identical in form with an intensive. This use of a pronoun modified byselfhas been attributed to British Celtic influence. Other changes in the pronominal system have been attributed to Scandinavian influence, e.g. the introduction of the third person plural pronounthey.This paper looks at the use of the specially marked reflexives in the glosses to the Lindisfarne Gospels, a northern text where both British Celtic and Scandinavian influence may be relevant. It provides lists of all of theself-marked forms and shows, for instance, that Matthew and Mark have reflexives based on an accusative/dative pronoun followed byselfand they don’t have this form as an intensifier. British Celtic of this period has an intensifier but has no special reflexives and has lost case endings, so the Lindisfarne language is unlike British Celtic. Luke and John have intensives and reflexives, with ‘self’ modifying case-marked pronouns, again unlike British Celtic. In addition to contributing to the debate on external origins, the paper adds to the authorship debate by comparing the use of reflexives in the different gospels.
What doesāgenmean in the Lindisfarne Gospels?
Authors: Vezzosi Letizia
Published: December 2019

Aldred’s interlinear glosses added to the Latin text of the Lindisfarne Gospels have undoubtedly an inestimable value as one of the most substantial representatives of late Old Northumbrian. Therefore, they have been an object of study both as a source of information on this Old English variety and on the typological changes affecting Middle English. Starting from the assumption that glosses have an ancillary function with respect to the Latin text they accompany, I have argued in the present paper that they can make a significant contribution to delineating the history and meaning of a word inasmuch as glossators could have chosen vernacular words according to their core meaning. The particular case of the verbs of possessionāganand the forms derived from it, including the past participleāgen, will be used in the following discussion of the role of glosses: the investigation of their meaning in the Lindisfarne Gospels will help us understand the development ofāgeninto the PDE attributive intensifierown.
Ca2+ transients in melanocyte dendrites and dendritic spine-like structures evoked by cell-to-cell signaling
Authors: Belote Rachel L. , Simon Sanford M.
Published: December 2019

Melanocytes are the neural crest–derived pigment-producing cells of the skin that possess dendrites. Yet little is known about how melanocyte dendrites receive and process information from neighboring cells. Here, using a co-culture system to interrogate the interaction between melanocyte dendrites and keratinocytes, we show that signals from neighboring keratinocytes trigger local compartmentalized Ca2+ transients within the melanocyte dendrites. The localized dendritic Ca2+ transients could be triggered by two keratinocyte-secreted factors, endothelin and acetylcholine, which acted via specific melanocyte receptors. Furthermore, compartmentalized Ca2+ transients were also generated on discrete dendritic spine-like structures on the melanocytes. These spines were also present in intact human skin. Our findings provide insights into how melanocyte dendrites communicate with neighboring cells and offer a new model system for studying compartmentalized signaling in dendritic structures.
Wnt5a induces and maintains prostate cancer cells dormancy in bone
Authors: Ren Dong , Dai Yuhu , Yang Qing , Zhang Xin , Guo Wei , Ye Liping , Huang Shuai , Chen Xu , Lai Yingrong , Du Hong , Lin Chuyong , Peng Xinsheng , Song Libing
Published: December 2019

In a substantial fraction of prostate cancer (PCa) patients, bone metastasis appears after years or even decades of latency. Canonical Wnt/β-catenin signaling has been proposed to be implicated in dormancy of cancer cells. However, how these tumor cells are kept dormant and recur under control of Wnt/β-catenin signaling derived from bone microenvironment remains unknown. Here, we report that Wnt5a from osteoblastic niche induces dormancy of PCa cells in a reversible manner in vitro and in vivo via inducing Siah E3 Ubiquitin Protein Ligase 2 (SIAH2) expression, which represses Wnt/β-catenin signaling. Furthermore, this effect of Wnt5a-induced dormancy of PCa cells depends on receptor tyrosine kinase-like orphan receptor 2 (ROR2), and a negative correlation of ROR2 expression with bone metastasis–free survival is observed in PCa patients. Therefore, these results demonstrate that Wnt5a/ROR2/SIAH2 signaling axis plays a crucial role in inducing and maintaining PCa cells dormancy in bone, suggesting a potential therapeutic utility of Wnt5a via inducing dormancy of PCa cells in bone.
Essential phenotypes of NOTCH2NLC-related repeat expansion disorder
Authors: Westenberger Ana , Klein Christine
Published: December 2019

This scientific commentary refers to ‘Expansion of GGC repeat in human-specific NOTCH2NLC gene is associated with essential tremor’ by Sun et al. (doi: 10.1093/brain/awz372).
Mapping migraine to a common brain network
Authors: Burke Matthew J , Joutsa Juho , Cohen Alexander L , Soussand Louis , Cooke Danielle , Burstein Rami , Fox Michael D
Published: December 2019

Inconsistent findings from migraine neuroimaging studies have limited attempts to localize migraine symptomatology. Novel brain network mapping techniques offer a new approach for linking neuroimaging findings to a common neuroanatomical substrate and localizing therapeutic targets. In this study, we attempted to determine whether neuroanatomically heterogeneous neuroimaging findings of migraine localize to a common brain network. We used meta-analytic coordinates of decreased grey matter volume in migraineurs as seed regions to generate resting state functional connectivity network maps from a normative connectome (n = 1000). Network maps were overlapped to identify common regions of connectivity across all coordinates. Specificity of our findings was evaluated using a whole-brain Bayesian spatial generalized linear mixed model and a region of interest analysis with comparison groups of chronic pain and a neurologic control (Alzheimer’s disease). We found that all migraine coordinates (11/11, 100%) were negatively connected (t ≥ ±7, P < 10−6 family-wise error corrected for multiple comparisons) to a single location in left extrastriate visual cortex overlying dorsal V3 and V3A subregions. More than 90% of coordinates (10/11) were also positively connected with bilateral insula and negatively connected with the hypothalamus. Bayesian spatial generalized linear mixed model whole-brain analysis identified left V3/V3A as the area with the most specific connectivity to migraine coordinates compared to control coordinates (voxel-wise probability of ≥90%). Post hoc region of interest analyses further supported the specificity of this finding (ANOVA P = 0.02; pairwise t-tests P = 0.03 and P = 0.003, respectively). In conclusion, using coordinate-based network mapping, we show that regions of grey matter volume loss in migraineurs localize to a common brain network defined by connectivity to visual cortex V3/V3A, a region previously implicated in mechanisms of cortical spreading depression in migraine. Our findings help unify migraine neuroimaging literature and offer a migraine-specific target for neuromodulatory treatment.
Genetic dysregulation of endothelin-1 is implicated in coronary microvascular dysfunction
Authors: Ford Thomas J , Corcoran David , Padmanabhan Sandosh , Aman Alisha , Rocchiccioli Paul , Good Richard , McEntegart Margaret , Maguire Janet J , Watkins Stuart , Eteiba Hany , Shaukat Aadil , Lindsay Mitchell , Robertson Keith , Hood Stuart , McGeoch Ross , McDade Robert , Yii Eric , Sattar Naveed , Hsu Li-Yueh , Arai Andrew E , Oldroyd Keith G , Touyz Rhian M , Davenport Anthony P , Berry Colin
Published: December 2019

Aims

Endothelin-1 (ET-1) is a potent vasoconstrictor peptide linked to vascular diseases through a common intronic gene enhancer [(rs9349379-G allele), chromosome 6 (PHACTR1/EDN1)]. We performed a multimodality investigation into the role of ET-1 and this gene variant in the pathogenesis of coronary microvascular dysfunction (CMD) in patients with symptoms and/or signs of ischaemia but no obstructive coronary artery disease (CAD).

Methods and results

Three hundred and ninety-one patients with angina were enrolled. Of these, 206 (53%) with obstructive CAD were excluded leaving 185 (47%) eligible. One hundred and nine (72%) of 151 subjects who underwent invasive testing had objective evidence of CMD (COVADIS criteria). rs9349379-G allele frequency was greater than in contemporary reference genome bank control subjects [allele frequency 46% (129/280 alleles) vs. 39% (5551/14380); P = 0.013]. The G allele was associated with higher plasma serum ET-1 [least squares mean 1.59 pg/mL vs. 1.28 pg/mL; 95% confidence interval (CI) 0.10–0.53; P = 0.005]. Patients with rs9349379-G allele had over double the odds of CMD [odds ratio (OR) 2.33, 95% CI 1.10–4.96; P = 0.027]. Multimodality non-invasive testing confirmed the G allele was associated with linked impairments in myocardial perfusion on stress cardiac magnetic resonance imaging at 1.5 T (N = 107; GG 56%, AG 43%, AA 31%, P = 0.042) and exercise testing (N = 87; −3.0 units in Duke Exercise Treadmill Score; −5.8 to −0.1; P = 0.045). Endothelin-1 related vascular mechanisms were assessed ex vivo using wire myography with endothelin A receptor (ETA) antagonists including zibotentan. Subjects with rs9349379-G allele had preserved peripheral small vessel reactivity to ET-1 with high affinity of ETA antagonists. Zibotentan reversed ET-1-induced vasoconstriction independently of G allele status.

Conclusion

We identify a novel genetic risk locus for CMD. These findings implicate ET-1 dysregulation and support the possibility of precision medicine using genetics to target oral ETA antagonist therapy in patients with microvascular angina.

Trial registration

ClinicalTrials.gov: NCT03193294.
Engineering G protein-coupled receptor signalling in yeast for biotechnological and medical purposes
Authors: Lengger Bettina , Jensen Michael K
Published: December 2019

G protein-coupled receptors (GPCRs) comprise the largest class of membrane proteins in the human genome, with a common denominator of seven-transmembrane domains largely conserved among eukaryotes. Yeast is naturally armoured with three different GPCRs for pheromone and sugar sensing, with the pheromone pathway being extensively hijacked for characterising heterologous GPCR signalling in a model eukaryote. This review focusses on functional GPCR studies performed in yeast and on the elucidated hotspots for engineering, and discusses both endogenous and heterologous GPCR signalling. Key emphasis will be devoted to studies describing important engineering parameters to consider for successful coupling of GPCRs to the yeast mating pathway. We also review the various means of applying yeast for studying GPCRs, including the use of yeast armed with heterologous GPCRs as a platform for (i) deorphanisation of orphan receptors, (ii) metabolic engineering of yeast for production of bioactive products and (iii) medical applications related to pathogen detection and drug discovery. Finally, this review summarises the current challenges related to expression of functional membrane-bound GPCRs in yeast and discusses the opportunities to continue capitalising on yeast as a model chassis for functional GPCR signalling studies.
Crustal seismic anisotropy of the Northeastern Tibetan Plateau and the adjacent areas from shear-wave splitting measurements
Authors: Hu Nan , Li Yonghua , Xu Liangxin
Published: December 2019

The Northeastern Tibetan Plateau has thickened crust and is still undergoing strong active crustal shortening and deformation. Crustal anisotropy can provide clues to how the crust is currently deforming and evolving. We use an automatic method to analyse the upper-crustal anisotropy of the NE Tibetan Plateau and the adjacent region using local earthquakes recorded at 39 permanent seismic stations during the period 2009–2018. The majority of the dominant fast directions are consistent with the maximum horizontal stress orientation, suggesting that the upper-crustal anisotropy is mainly controlled by the regional or local stress field. Several fault-parallel measurements are observed for stations on or near to the main faults. These fault-parallel fast directions indicate that the main mechanism of upper-crustal anisotropy is associated with shear fabric caused by deformation. Fast directions neither fault-parallel nor stress-parallel are observed at stations lying several kilometres away from fault zones, likely reflecting the combined influence of stress-aligned microcracks and active faults. A comparison between our upper-crustal anisotropy parameters and those inferred from previous anisotropy studies that used receiver function and teleseismic shear wave splitting measurements suggests that the crust has the same deformation mechanisms as mantle anisotropy in the southern part of the Western Qinling Fault, whereas the upper-crustal anisotropic mechanism is different from those of lower crust and mantle anisotropy in the northern part of the Western Qinling Fault. These observations imply that the Western Qinling Fault may be an important boundary fault.
Critical consciousness development: a systematic review of empirical studies
Authors: Pillen Heath , McNaughton Darlene , Ward Paul R
Published: December 2019

Developing an understanding of the social and political basis of marginalization is an important educational task for health education guided by frameworks of social justice. With the intention of developing an evaluative framework for use in further research, the aim of this review article is to present a synthesized framework of critical consciousness development, developed from a systematic search and qualitative synthesis of empirical studies that have examined the processes by which individuals come to critically reflect upon and act on oppressive social relations. A systematic search was conducted examining English-language literature produced between January 1970 and May 2017 within databases of PsycINFO, SCOPUS and ProQuest. A total of 20 articles were selected following a two-stage screening process and an assessment of methodological quality. Thematic analysis of findings from these texts produced a framework of critical consciousness development consisting of six qualitative processes and the relationships between them, including the priming of critical reflection, information creating disequilibrium, introspection, revising frames of reference, developing agency for change and acting against oppression. This synthesized framework of critical consciousness development is presented as a useful tool for assessing learning within critical pedagogies, albeit requiring some modification to suit specific cultural contexts and epistemologies.
Genetic susceptibility to severe childhood asthma and rhinovirus-C maintained by balancing selection in humans for 150 000 years
Authors: O’Neill Mary B , Laval Guillaume , Teixeira João C , Palmenberg Ann C , Pepperell Caitlin S
Published: December 2019

Selective pressures imposed by pathogens have varied among human populations throughout their evolution, leading to marked inter-population differences at some genes mediating susceptibility to infectious and immune-related diseases. Here, we investigated the evolutionary history of a common polymorphism resulting in a Y529 versus C529 change in the cadherin related family member 3 (CDHR3) receptor which underlies variable susceptibility to rhinovirus-C infection and is associated with severe childhood asthma. The protective variant is the derived allele and is found at high frequency worldwide (69–95%). We detected genome-wide significant signatures of natural selection consistent with a rapid increase of the haplotypes carrying the allele, suggesting that non-neutral processes have acted on this locus across all human populations. However, the allele has not fixed in any population despite multiple lines of evidence suggesting that the mutation predates human migrations out of Africa. Using an approximate Bayesian computation method, we estimate the age of the mutation while explicitly accounting for past demography and positive or frequency-dependent balancing selection. Our analyses indicate a single emergence of the mutation in anatomically modern humans ~150 000 years ago and indicate that balancing selection has maintained the beneficial allele at high equilibrium frequencies worldwide. Apart from the well-known cases of the MHC and ABO genes, this study provides the first evidence that negative frequency-dependent selection plausibly acted on a human disease susceptibility locus, a form of balancing selection compatible with typical transmission dynamics of communicable respiratory viruses that might exploit CDHR3.
Efficacy of Fecal Microbiota Transplantation for Recurrent C. Difficile Infection in Inflammatory Bowel Disease
Authors: Tariq Raseen , Disbrow Molly B , Dibaise John K , Orenstein Robert , Saha Srishti , Solanky Dipesh , Loftus Edward V , Pardi Darrell S , Khanna Sahil
Published: December 2019

Background

Clostridioides difficile infection (CDI) is associated with poor outcomes in inflammatory bowel disease (IBD) patients. Data are scarce on efficacy of fecal microbiota transplant (FMT) for recurrent CDI in IBD patients.

Methods

We reviewed health records of IBD patients (18 years of age or older) with recurrent CDI who underwent FMT. Outcomes of FMT for CDI were assessed on the basis of symptoms and stool test results.

Results

We included 145 patients (75 women [51.7%]; median age, 46 years). Median IBD duration was 8 (range, 0–47) years, 36.6% had Crohn disease, 61.4% had ulcerative colitis, and 2.1% had indeterminate colitis. Median number of prior CDI episodes was 3 (range, 3–20), and 61.4% had received vancomycin taper. Diarrhea resolved after FMT in 48 patients (33.1%) without further testing. Ninety-five patients (65.5%) underwent CDI testing owing to post-FMT recurrent diarrhea; 29 (20.0%) had positive results. After FMT, 2 patients received empiric treatment of recurrent CDI without symptom resolution, suggesting IBD was the cause of symptoms. The overall cure rate of CDI after FMT was 80.0%, without CDI recurrence at median follow-up of 9.3 (range, 0.1–51) months. Forty-three patients (29.7%) had planned IBD therapy escalation after CDI resolution; none de-escalated or discontinued IBD therapy. Overall, 7.6% had worsening IBD symptoms after FMT that were treated as new IBD flares. No clinical predictors of FMT failure were identified.

Conclusions

Few patients had new IBD flare after FMT. Fecal microbiota transplantation effectively treats recurrent CDI in IBD patients but has no apparent beneficial effect on the IBD course.
On Smooth Projective D-Affine Varieties
Authors: Langer Adrian
Published: December 2019

We show various properties of smooth projective D-affine varieties. In particular, any smooth projective D-affine variety is algebraically simply connected and its image under a fibration is D-affine. In characteristic 0 such D-affine varieties are also uniruled. We also show that (apart from a few small characteristics) a smooth projective surface is D-affine if and only if it is isomorphic to either ${{\mathbb{P}}}^2$ or ${{\mathbb{P}}}^1\times{{\mathbb{P}}}^1$. In positive characteristic, a basic tool in the proof is a new generalization of Miyaoka’s generic semipositivity theorem.
Current Understanding of Cytomegalovirus Reactivation in Critical Illness
Authors: Imlay Hannah , Limaye Ajit P
Published: December 2019

Cytomegalovirus (CMV) reactivation has been described in adults with critical illness caused by diverse etiologies, especially severe sepsis, and observational studies have linked CMV reactivation with worse clinical outcomes in this setting. In this study, we review observational clinical data linking development of CMV reactivation with worse outcomes in patients in the intensive care unit, discuss potential biologically plausible mechanisms for a causal association, and summarize results of initial interventional trials that examined the effects of CMV prevention. These data, taken together, highlight the need for a randomized, placebo-controlled efficacy trial (1) to definitively determine whether prevention of CMV reactivation improves clinical outcomes of patients with critical illness and (2) to define the underlying mechanism(s).
Comparative Effectiveness of Combined Favipiravir and Oseltamivir Therapy Versus Oseltamivir Monotherapy in Critically Ill Patients With Influenza Virus Infection
Authors: Wang Yeming , Fan Guohui , Salam Alex , Horby Peter , Hayden Frederick G , Chen Cheng , Pan Jianguang , Zheng Jing , Lu Binghuai , Guo Liping , Wang Chen , Cao Bin
Published: December 2019

Background

A synergistic effect of combination therapy with favipiravir and oseltamivir has been reported in preclinical models of influenza. However, no data are available on the clinical effectiveness of combination therapy in severe influenza.

Methods

Data from 2 separate prospective studies of influenza adults were used to compare outcomes between combination and oseltamivir monotherapy. Outcomes included rate of clinical improvement (defined as a decrease of 2 categories on a 7-category ordinal scale) and viral RNA detectability over time. Subhazard ratios (sHRs) were estimated by the Fine and Gray model for competing risks.

Results

In total, 40 patients were treated with combination therapy and 128 with oseltamivir alone. Clinical improvement on day 14 in the combination group was higher than in the monotherapy group (62.5% vs 42.2%; P = .0247). The adjusted sHR for combination therapy was 2.06 (95% confidence interval, 1.30–3.26). The proportion of undetectable viral RNA at day 10 was higher in the combination group than the oseltamivir group (67.5% vs 21.9%; P < .01). No significant differences were observed in mortality or other outcomes.

Conclusions

Favipiravir and oseltamivir combination therapy may accelerate clinical recovery compared to oseltamivir monotherapy in severe influenza, and this strategy should be formally evaluated in a randomized controlled trial.
Validation of a novel hip arthroscopy simulator: establishing construct validity
Authors: Cychosz Christopher , Khazi Zain M , Karam Matthew , Duchman Kyle , Willey Michael , Westermann Robert
Published: December 2019

Hip arthroscopy (HA) is technically demanding and associated with a prolonged learning curve. Recently, arthroscopic simulators have been developed to anatomically model various joints including the knee, shoulder and hip. The purpose of this study is to validate a novel HA simulator. Twenty trainees and one sports medicine fellowship-trained orthopaedic surgeon at a single academic institution were recruited to perform a diagnostic HA procedure using the VirtaMed ArthroS hip simulator. Trainee characteristics, including level of training, general arthroscopy experience and hip specific arthroscopy experience, were gathered via questionnaire. For the purpose of this study, participants were categorized as novice (<25), intermediate (25–74) or experienced (≥75) based on the number of prior arthroscopies performed. Various performance metrics, including composite score, time and camera path length were recorded for each attempt. Metrics were analyzed categorically using ANOVA tests with significance set to P < 0.05. Composite performance score in the novice cohort was 114.5 compared with 146.4 and 151.5 in the intermediate and experienced cohorts (P = 0.0019), respectively. Novice arthroscopists performed the simulated diagnostic arthroscopy procedure in an average time of 321 s compared with 202 s and 181 s in the intermediate and experienced cohorts (P < 0.002), respectively. Cartilage damage and simulator safety score did not differ significantly between groups (P = 0.775). Simulator composite score and procedure time showed strong correlation with year of training (r = 0.65 and −0.70, respectively) and number of arthroscopies performed (r = 0.65 and −0.72). The ArthroS hip simulator shows good construct validity and performance correlates highly with total number of arthroscopic cases reported during training.
Incidence and Risk Factors of Upper Extremity Injuries in Young Adult Men: A Nationwide Registry-Based Study of 128,714 Conscripts
Authors: Pihlajamäki Harri , Silvennoinen Arttu , Kuikka Paavo-Ilari , Luukkaala Tiina , Kröger Heikki , Kyröläinen Heikki
Published: December 2019

Introduction

Injuries are the major cause of morbidity and loss of active training days in military populations. Previous investigations have mainly focused on lower extremities. This study evaluated the incidence, diagnosis, and risk factors of upper extremity injuries requiring hospitalization in a large cohort of Finnish conscripts during a 5-year period.

Materials and Methods

A total of 128,714 male military conscripts, who served 6–12 months in compulsory military service, were studied. Injury hospitalization data were obtained from the National Hospital Discharge Register. The main outcome variables were hospitalization due to any injuries to the upper extremity and hospitalization due to traumatic shoulder dislocation. Background variables for risk factor analysis included length of military service, age, body height and weight, body mass index, and physical fitness.

Results

Overall person-based incidence rate for hospitalization due to upper extremity injury was 743 (95% confidence interval [CI]: 697–791) per 100,000 conscripts per year. Shoulder joint dislocation was the most common injury: incidence rate of 103 (95% CI: 86–122) per 100,000 conscripts per year. Trend during follow-up years 1998–2002 was decreasing concerning on any upper extremity injuries (odd ratios [OR] 0.90; 95% CI: 0.86–0.95, P < 0.001). Body mass index > 25 increased a risk for any injuries of the upper extremity (OR 1.29; CI 95%: 1.10–1.51) and, especially, for shoulder joint dislocation (OR 1.88; CI 95%: 1.26–2.80).

Conclusions

Overweight young men were at greater risk for upper extremity injuries. The incidence rate of traumatic shoulder joint dislocation was considerably higher than reported previously. In conclusion, preventive measures such as reducing the body weight of overweight young men should play an important role in reducing the incidence of upper extremity injuries.
ALMA and ROSINA detections of phosphorus-bearing molecules: the interstellar thread between star-forming regions and comets
Authors: Rivilla V M , Drozdovskaya M N , Altwegg K , Caselli P , Beltrán M T , Fontani F , van der Tak F F S , Cesaroni R , Vasyunin A , Rubin M , Lique F , Marinakis S , Testi L ,   the ROSINA team, Balsiger H , Berthelier J J , De Keyser J , Fiethe B , Fuselier S A , Gasc S , Gombosi T I , Sémon T , Tzou C-Y
Published: December 2019

To understand how phosphorus (P)-bearing molecules are formed in star-forming regions, we have analysed the Atacama Large Millimeter/Submillimeter Array (ALMA) observations of PN and PO towards the massive star-forming region AFGL 5142, combined with a new analysis of the data of the comet 67P/Churyumov–Gerasimenko taken with the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument onboard Rosetta. The ALMA maps show that the emission of PN and PO arises from several spots associated with low-velocity gas with narrow linewidths in the cavity walls of a bipolar outflow. PO is more abundant than PN in most of the spots, with the PO/PN ratio increasing as a function of the distance to the protostar. Our data favour a formation scenario in which shocks sputter phosphorus from the surface of dust grains, and gas-phase photochemistry induced by UV photons from the protostar allows efficient formation of the two species in the cavity walls. Our analysis of the ROSINA data has revealed that PO is the main carrier of P in the comet, with PO/PN > 10. Since comets may have delivered a significant amount of prebiotic material to the early Earth, this finding suggests that PO could contribute significantly to the phosphorus reservoir during the dawn of our planet. There is evidence that PO was already in the cometary ices prior to the birth of the Sun, so the chemical budget of the comet might be inherited from the natal environment of the Solar system, which is thought to be a stellar cluster including also massive stars.
Following the crumbs: statistical effects of ram pressure in galaxies
Authors: Rodríguez S , Garcia Lambas D , Padilla N D , Troncoso-Iribarren P
Published: December 2019

We analyse the presence of dust around galaxy group members through the reddening of background quasars. By taking into account quasar colour and their dependence on redshift and angular position, we derive mean quasar colours excess in projected regions around member galaxies and infer the associated dust mass. For disc-like galaxies perpendicular to the plane of the sky, and at groupcentric distances of the order of the virial radius, thus likely to reside in the infall regions of groups, we find systematic colour excess values e ∼ 0.009 ± 0.004 for g − r colour. Under the hypothesis of Milky Way dust properties, we derive dust masses of $5.8 \pm 2.5 \times 10^8 \, \mathrm{M}_{\odot }\, h^{-1}$, implying that a large fraction of dust is being stripped from galaxies in their path to groups. We also studied the photometry of member galaxies to derive a colour asymmetry relative to the group centre direction from a given galaxy. We conclude that the regions of galaxies facing the centre are bluer, consistent with the effects of gas compression and star formation. We also combine these two procedures finding that galaxies with a small colour asymmetry show the largest amounts of dust towards the external regions compared to a control sample. We conclude that dust removal is very efficient in galaxies on infall. The fact that galaxies redder towards groups centres are associated with the strongest reddening of background quasars suggest that gas removal induced by ram pressure stripping plays a key role in galaxy evolution and dust content.
A fast quadrature-based gravity model for the homogeneous polyhedron
Authors: Pearl Jason M , Hitt Darren L
Published: December 2019

To date several probes have been sent to explore the Solar system’s asteroids and comets. These bodies are often irregular in shape and to safely navigate probes in their vicinity accurate gravity models are required. For an arbitrarily shaped constant-density body, the gravitational field can be determined from the surface topology and bulk properties. This is achieved by replacing the body’s true geometry with a polyhedron that closely resembles it and for which analytic equations for the gravitational field exist. For some applications however, these equations are too computationally expensive and it can be beneficial to replace them with numerically amenable approximations. In this work, a numerical-quadrature-based model for the gravitational field of a polyhedron consisting of triangular facets is derived. The proposed approximate model is found to be faster than its analytic counterpart. The error of the approximation is found to be negligible for the potential and Laplacian calculations. The approximate model introduces singularities to the surface of the acceleration calculation degrading the solution at altitudes less than the average edge length of the polyhedron.
On reverberation mapping lag uncertainties
Authors: Yu Z , Kochanek C S , Peterson B M , Zu Y , Brandt W N , Cackett E M , Fausnaugh M M , McHardy I M
Published: December 2019

We broadly explore the effects of systematic errors on reverberation mapping lag uncertainty estimates from javelin and the interpolated cross-correlation function (ICCF) method. We focus on simulated light curves from random realizations of the light curves of five intensively monitored AGNs. Both methods generally work well even in the presence of systematic errors, although javelin generally provides better error estimates. Poorly estimated light-curve uncertainties have less effect on the ICCF method because, unlike javelin , it does not explicitly assume Gaussian statistics. Neither method is sensitive to changes in the stochastic process driving the continuum or the transfer function relating the line light curve to the continuum. The only systematic error we considered that causes significant problems is if the line light curve is not a smoothed and shifted version of the continuum light curve but instead contains some additional sources of variability.
Renormalization of linear halo bias in N-body simulations
Authors: Werner Kim F , Porciani Cristiano
Published: December 2019

The interpretation of redshift surveys requires modelling the relationship between large-scale fluctuations in the observed number density of tracers, δh, and the underlying matter density, δ. Bias models often express δh as a truncated series of integro-differential operators acting on δ, each weighted by a bias parameter. Due to the presence of ‘composite operators’ (obtained by multiplying fields evaluated at the same spatial location), the linear bias parameter measured from clustering statistics does not coincide with that appearing in the bias expansion. This issue can be cured by re-writing the expansion in terms of ‘renormalized’ operators. After providing a pedagogical and comprehensive review of bias renormalization in perturbation theory, we generalize the concept to non-perturbative dynamics and successfully apply it to dark-matter haloes extracted from a large suite of N-body simulations. When comparing numerical and perturbative results, we highlight the effect of the window function employed to smooth the random fields. We then measure the bias parameters as a function of halo mass by fitting a non-perturbative bias model (both before and after applying renormalization) to the cross spectrum $P_{\delta _\mathrm{h}\delta }(k)$. Finally, we employ Bayesian model selection to determine the optimal operator set to describe $P_{\delta _\mathrm{h}\delta }(k)$ for $k\lt 0.2\, h$ Mpc−1 at redshift z = 0. We find that it includes δ, ∇2δ, δ2 and the square of the traceless tidal tensor, s2. Considering higher order terms (in δ) leads to overfitting as they cannot be precisely constrained by our data. We also notice that next-to-leading-order perturbative solutions are inaccurate for k ≳ 0.1 h Mpc−1.
Warm dark matter chills out: constraints on the halo mass function and the free-streaming length of dark matter with eight quadruple-image strong gravitational lenses
Authors: Gilman Daniel , Birrer Simon , Nierenberg Anna , Treu Tommaso , Du Xiaolong , Benson Andrew
Published: December 2019

The free-streaming length of dark matter depends on fundamental dark matter physics, and determines the abundance and concentration of dark matter haloes on sub-galactic scales. Using the image positions and flux ratios from eight quadruply imaged quasars, we constrain the free-streaming length of dark matter and the amplitude of the subhalo mass function (SHMF). We model both main deflector subhaloes and haloes along the line of sight, and account for warm dark matter free-streaming effects on the mass function and mass–concentration relation. By calibrating the scaling of the SHMF with host halo mass and redshift using a suite of simulated haloes, we infer a global normalization for the SHMF. We account for finite-size background sources, and marginalize over the mass profile of the main deflector. Parametrizing dark matter free-streaming through the half-mode mass mhm, we constrain the thermal relic particle mass mDM corresponding to mhm. At $95 \, {\rm per\, cent}$ CI: mhm < 107.8 M⊙ ($m_{\rm {DM}} \gt 5.2 \ \rm {keV}$). We disfavour $m_{\rm {DM}} = 4.0 \,\rm {keV}$ and $m_{\rm {DM}} = 3.0 \,\rm {keV}$ with likelihood ratios of 7:1 and 30:1, respectively, relative to the peak of the posterior distribution. Assuming cold dark matter, we constrain the projected mass in substructure between 106 and 109 M⊙ near lensed images. At $68 \, {\rm per\, cent}$ CI, we infer $2.0{-}6.1 \times 10^{7}\, {{\rm M}_{\odot }}\,\rm {kpc^{-2}}$, corresponding to mean projected mass fraction $\bar{f}_{\rm {sub}} = 0.035_{-0.017}^{+0.021}$. At $95 \, {\rm per\, cent}$ CI, we obtain a lower bound on the projected mass of $0.6 \times 10^{7} \,{{\rm M}_{\odot }}\,\rm {kpc^{-2}}$, corresponding to $\bar{f}_{\rm {sub}} \gt 0.005$. These results agree with the predictions of cold dark matter.
Effects of photoevaporation on protoplanetary disc ‘isochrones’
Authors: Somigliana Alice , Toci Claudia , Lodato Giuseppe , Rosotti Giovanni , Manara Carlo F
Published: December 2019

Protoplanetary discs are the site of star and planet formation, and their evolution and consequent dispersal deeply affect the formation of planetary systems. In the standard scenario they evolve on time-scales ∼Myr due to the viscous transport of angular momentum. The analytical self-similar solution for their evolution predicts specific disc isochrones in the accretion rate–disc mass plane. However, photoevaporation by radiation emitted by the central star is likely to dominate the gas disc dispersal of the innermost region, introducing another (shorter) time-scale for this process. In this paper, we include the effect of internal (X and EUV) photoevaporation on the disc evolution, finding numerical solutions for a population of protoplanetary discs. Our models naturally reproduce the expected quick dispersal of the inner region of discs when their accretion rates match the rate of photoevaporative mass loss, in line with previous studies. We find that photoevaporation preferentially removes the lightest discs in the sample. The net result is that, counter-intuitively, photoevaporation increases the average disc mass in the sample, by dispersing the lightest discs. At the same time, photoevaporation also reduces the mass accretion rate by cutting the supply of material from the outer to the inner disc. In a purely viscous framework, this would be interpreted as the result of a longer viscous evolution, leading to an overestimate of the disc age. Our results thus show that photoevaporation is a necessary ingredient to include when interpreting observations of large disc samples with measured mass accretion rates and disc masses. Photoevaporation leaves a characteristic imprint on the shape of the isochrone. Accurate data of the accretion rate–disc mass plane in the low disc mass region therefore give clues on the typical photoevaporation rate.
The impact of non-dipolar magnetic fields in core-collapse supernovae
Authors: Bugli M , Guilet J , Obergaulinger M , Cerdá-Durán P , Aloy M A
Published: December 2019

The magnetic field is believed to play an important role in at least some core-collapse supernovae (CCSN) if its magnitude reaches $10^{15}\, \rm {G}$, which is a typical value for a magnetar. In the presence of fast rotation, such a strong magnetic field can drive powerful jet-like explosions if it has the large-scale coherence of a dipole. The topology of the magnetic field is, however, probably much more complex with strong multipolar and small-scale components and the consequences for the explosion are so far unclear. We investigate the effects of the magnetic field topology on the dynamics of CCSN and the properties of the forming proto-neutron star (PNS) by comparing pre-collapse fields of different multipolar orders and radial profiles. Using axisymmetric special relativistic MHD simulations and a two-moment neutrino transport, we find that higher multipolar magnetic configurations lead to generally less energetic explosions, slower expanding shocks, and less collimated outflows. Models with a low order multipolar configuration tend to produce more oblate PNS, surrounded in some cases by a rotationally supported toroidal structure of neutron-rich material. Moreover, magnetic fields which are distributed on smaller angular scales produce more massive and faster rotating central PNS, suggesting that higher order multipolar configurations tend to decrease the efficiency of the magnetorotational launching mechanism. Even if our dipolar models systematically display a far more efficient extraction of the rotational energy of the PNS, fields distributed on smaller angular scales are still capable of powering magnetorotational explosions and shape the evolution of the central compact object.
Pulsation in faint blue stars
Authors: Byrne Conor M , Jeffery C Simon
Published: December 2019

Following the discovery of blue large-amplitude pulsators (BLAPs) by the OGLE survey, additional hot, high-amplitude pulsating stars have been discovered by the Zwicky Transient Facility. It has been proposed that all of these objects are low-mass pre-white dwarfs and that their pulsations are driven by the opacity of iron-group elements. With this expanded population of pulsating objects, it was decided to compute a sequence of post-common-envelope stellar models using the mesa stellar evolution code and to examine the pulsation properties of low-mass pre-white dwarfs using non-adiabatic analysis with the gyre stellar oscillation code. By including the effects of atomic diffusion and radiative levitation, it is shown that a large region of instability exists from effective temperatures of 30 000 K up to temperatures of at least 50 000 K and at a wide range of surface gravities. This encompasses both groups of pulsator observed so far, and confirms that the driving mechanism is through iron group element opacity. We make some conservative estimates about the range of periods, masses, temperatures, and gravities in which further such pulsators might be observed.
Leptonic modelling of Ton 599 in flare and quiescent states
Authors: Patel S R , Chitnis V R
Published: December 2019

The flat-spectrum radio quasar Ton 599 attained its highest ever γ-ray flux state during the first week of 2017 November. Observations of the source by the Swift satellite during this period made it possible to generate a simultaneous high flux state broad-band spectral energy distribution (SED). The high flux state activity of Ton 599 is modelled in this work for the first time. We modelled one high flux state and one quiescent state of the source in order to characterize the evolution of SEDs covering the entire dynamic range of γ-ray flux observed by Fermi-LAT. An attempt was made to model the 2017 November state of the source using an external Compton (EC) model in the leptonic scenario. We reproduce the broad-band flaring state SED using a two-component leptonic emission model. We considered one component as an EC+synchrotron self-Compton (SSC) component and the other as pure SSC, lying further down in the jet. The EC+SSC component was located outside the broad-line region (BLR). It mainly reproduces the GeV emission by an EC process with a dusty torus (DT) photon field providing seed photons. We reproduce the broad-band emission from Ton 599 satisfactorily during its peculiar flaring state with a leptonic two-component model. Besides this, we compare the model parameters of a quiescent-state SED with the available average state model parameters in the literature.
When H ii regions are complicated: considering perturbations from winds, radiation pressure, and other effects
Authors: Geen Sam , Pellegrini Eric , Bieri Rebekka , Klessen Ralf
Published: December 2019

We explore to what extent simple algebraic models can be used to describe H ii regions when winds, radiation pressure, gravity, and photon breakout are included. We (a) develop algebraic models to describe the expansion of photoionized H ii regions under the influence of gravity and accretion in power-law density fields with ρ ∝ r−w, (b) determine when terms describing winds, radiation pressure, gravity, and photon breakout become significant enough to affect the dynamics of the H ii region where w = 2, and (c) solve these expressions for a set of physically motivated conditions. We find that photoionization feedback from massive stars is the principal mode of feedback on molecular cloud scales, driving accelerating outflows from molecular clouds in cases where the peaked density structure around young massive stars is considered at radii between ∼0.1 and 10–100 pc. Under a large range of conditions the effect of winds and radiation on the dynamics of H ii regions is around 10 per cent of the contribution from photoionization. The effect of winds and radiation pressure is most important at high densities, either close to the star or in very dense clouds such as those in the Central Molecular Zone of the Milky Way. Out to ∼0.1 pc they are the principal drivers of the H ii region. Lower metallicities make the relative effect of photoionization even stronger as the ionized gas temperature is higher.
Conformational ensembles of an RNA hairpin using molecular dynamics and sparse NMR data
Authors: Reißer Sabine , Zucchelli Silvia , Gustincich Stefano , Bussi Giovanni
Published: December 2019

Solution nuclear magnetic resonance (NMR) experiments allow RNA dynamics to be determined in an aqueous environment. However, when a limited number of peaks are assigned, it is difficult to obtain structural information. We here show a protocol based on the combination of experimental data (Nuclear Overhauser Effect, NOE) and molecular dynamics simulations with enhanced sampling methods. This protocol allows to (a) obtain a maximum entropy ensemble compatible with NMR restraints and (b) obtain a minimal set of metastable conformations compatible with the experimental data (maximum parsimony). The method is applied to a hairpin of 29 nt from an inverted SINEB2, which is part of the SINEUP family and has been shown to enhance protein translation. A clustering procedure is introduced where the annotation of base-base interactions and glycosidic bond angles is used as a metric. By reweighting the contributions of the clusters, minimal sets of four conformations could be found which are compatible with the experimental data. A motif search on the structural database showed that some identified low-population states are present in experimental structures of other RNA transcripts. The introduced method can be applied to characterize RNA dynamics in systems where a limited amount of NMR information is available.