bluuebunny/crossref_metadata_2025 huggingface dataset:
Hot accelerated qubits: decoherence, thermalization, secular growth and reliable late-time predictions
Authors: Kaplanek Greg , Burgess C. P.
Published: March 2020

Abstract

We compute how an accelerating qubit coupled to a scalar field — i.e. an Unruh-DeWitt detector — evolves in flat space, with an emphasis on its late-time behaviour. When calculable, the qubit evolves towards a thermal state for a field prepared in the Minkowski vacuum, with the approach to this limit controlled by two different time-scales. For a free field we compute both of these as functions of the difference between qubit energy levels, the dimensionless qubit/field coupling constant, the scalar field mass and the qubit’s proper acceleration. Both time-scales differ from the Candelas-Deutsch-Sciama transition rate traditionally computed for Unruh-DeWitt detectors, which we show describes the qubit’s early-time evolution away from the vacuum rather than its late-time approach to equilibrium. For small enough couplings and sufficiently late times the evolution is Markovian and described by a Lindblad equation, which we derive in detail from first principles as a special instance of Open EFT methods designed to handle a breakdown of late-time perturbative predictions due to the presence of secular growth. We show how this growth is resummed in this example to give reliable information about late-time evolution including both qubit/field interactions and field self-interactions. By allowing very explicit treatment, the qubit/field system allows a systematic assessment of the approximations needed when exploring late-time evolution, in a way that lends itself to gravitational applications. It also allows a comparison of these approximations with those — e.g. the ‘rotating-wave’ approximation — widely made in the open-system literature (which is aimed more at atomic transitions and lasers).
Modification of the laws of gravity in the DGP model by the presence of a second DGP brane
Authors: Warkentin Max
Published: March 2020

Abstract

We investigate how the laws of gravity change in the DGP model, if we add a second, parallel 3-brane, endowed with a localized gravitational curvature term. We calculate the gravitational potential energy between two static point sources localized on different branes. We discover a new length scale, which is equal to the geometric mean of the DGP cross-over scale and the separation of the two branes in the extra dimension. For distances, which are larger than this new length scale, we recover the original DGP result, but for smaller distances the gravitational potential is weaker. Furthermore, a region emerges, where a 4-dimensional observer measures a distance independent force. We discuss a possible application of the present scenario for deriving rotation curves of low surface brightness galaxies. Using the Kaluza-Klein description, we observe a curious pattern, in which even and odd KK-modes contribute to the attractive and repulsive parts of the gravitational potential, respectively. Finally, since this setup allows for the existence of a sector of particle species that are interacting arbitrarily weakly with “our” sector, we discuss the implications of this phenomenon for black holes and the bound on the number of species. We find that the behavior is qualitatively different from theories with a normalizable zero-mode graviton.
Production Tools Made by Additive Manufacturing Through Laser-based Powder Bed Fusion
Authors: Asnafi Nader , Rajalampi Jukka , Aspenberg David , Alveflo Anton
Published: March 2020

This paper deals with the design and production of stamping tools and dies for sheet metal components and injection molds for plastic components. Laser-based Powder Bed Fusion (LPBF) is the additive manufacturing method used in this investigation. Solid and topology optimized stamping tools and dies 3D-printed in DIN 1.2709 (maraging steel) by LPBF are approved/certified for stamping of up to 2‑mm thick hot-dip galvanized DP600 (dual-phase steel sheet). The punch in a working station in a progressive die used for stamping of 1‑mm thick hot-dip galvanized DP600 is 3D-printed in DIN 1.2709, both with a honeycomb inner structure and after topology optimization, with successful results. 3D printing results in a significant lead time reduction and improved tool material efficiency. The cost of 3D-printed stamping tools and dies is higher than the cost of those made conventionally. The core (inserts) of an injection mold is 3D-printed in DIN 1.2709, conformal cooling optimized and 3D-printed in Uddeholm AM Corrax, and compared with the same core made conventionally. The cooling and cycle time can be improved, if the injection molding core (inserts) is optimized and 3D-printed in Uddeholm AM Corrax. This paper accounts for the results obtained in the above-mentioned investigations.
The crosstalk of NAD, ROS and autophagy in cellular health and ageing
Authors: Sedlackova Lucia , Korolchuk Viktor I.
Published: March 2020

Cellular adaptation to various types of stress requires a complex network of steps that altogether lead to reconstitution of redox balance, degradation of damaged macromolecules and restoration of cellular metabolism. Advances in our understanding of the interplay between cellular signalling and signal translation paint a complex picture of multi-layered paths of regulation. In this review we explore the link between cellular adaptation to metabolic and oxidative stresses by activation of autophagy, a crucial cellular catabolic pathway. Metabolic stress can lead to changes in the redox state of nicotinamide adenine dinucleotide (NAD), a co-factor in a variety of enzymatic reactions and thus trigger autophagy that acts to sequester intracellular components for recycling to support cellular growth. Likewise, autophagy is activated by oxidative stress to selectively recycle damaged macromolecules and organelles and thus maintain cellular viability. Multiple proteins that help regulate or execute autophagy are targets of post-translational modifications (PTMs) that have an effect on their localization, binding affinity or enzymatic activity. These PTMs include acetylation, a reversible enzymatic modification of a protein’s lysine residues, and oxidation, a set of reversible and irreversible modifications by free radicals. Here we highlight the latest findings and outstanding questions on the interplay of autophagy with metabolic stress, presenting as changes in NAD levels, and oxidative stress, with a focus on autophagy proteins that are regulated by both, oxidation and acetylation. We further explore the relevance of this multi-layered signalling to healthy human ageing and their potential role in human disease.
Foucault’s Bentham: Fact or Fiction?
Authors: Safaei Sajjad
Published: March 2020

One would be hard-pressed to name an edifice that has dominated the academic imagination as thoroughly and exhaustively as Jeremy Bentham’s Panopticon. This somewhat monomaniacal fixation on one of Bentham’s many penal contraptions is rooted, to no small degree, in Michel Foucault’s now voguish theory of power, as expounded upon in his seminal work Discipline and Punish. Foucault’s understanding of Bentham’s penal thought, particularly the Panopticon, forms one of the key linchpins which his broad historical claims hinge upon. But to what extent does Foucault’s representation of Bentham’s penal theories, in particular, his views on the prison and the Panopticon, converge with how Bentham himself gave expression to his own penal philosophy? This question is examined in this article by taking a closer look at The Rationale of Punishment, a compilation of a vast mass of Bentham’s manuscripts, which were first published in English in 1830.
Measurement Properties of the Suicidal Behaviour Questionnaire-Revised in Autistic Adults
Authors: Cassidy Sarah A. , Bradley Louise , Cogger-Ward Heather , Shaw Rebecca , Bowen Erica , Glod Magdalena , Baron-Cohen Simon , Rodgers Jacqui
Published: March 2020

We explored the appropriateness and measurement properties of a suicidality assessment tool (SBQ-R) developed for the general population, in autistic adults—a high risk group for suicide. 188 autistic adults and 183 general population adults completed the tool online, and a sub-sample (n = 15) were interviewed while completing the tool. Multi-group factorial invariance analysis of the online survey data found evidence for metric non-invariance of the SBQ-R, particularly for items three (communication of suicidal intent) and four (likelihood of suicide attempt in the future). Cognitive interviews revealed that autistic adults did not interpret these items as intended by the tool designers. Results suggest autistic adults interpret key questions regarding suicide risk differently to the general population. Future research must adapt tools to better capture suicidality in autistic adults.
Supporting Japanese Mothers of Children at Risk for Attention Deficit Hyperactivity Disorder (ADHD): A Small Scale Randomized Control Trial of Well Parent Japan
Authors: Shimabukuro Shizuka , Daley David , Thompson Margaret , Laver-Bradbury Cathy , Lovern Kaoruko , Tripp Gail
Published: March 2020

Objectives

Guidelines recommend parent management training in the multi-modal treatment of attention deficit hyperactivity disorder (ADHD). The availability of such interventions in Japan is limited. This study evaluated the effects of Well Parent Japan, a hybrid intervention including a group Japanese language adaptation of the New Forest Parenting Programme for ADHD (NFPP) augmented with strategies to improve parent’s psychological wellbeing and enhance confidence in their ability to implement change.

Methods

Mothers of children aged 6–12 years displaying marked symptoms of ADHD were randomly assigned to the intervention (n = 28) or a waitlist control condition (n = 24). Measures were completed at baseline and again 14 weeks later. Parenting stress was the primary outcome. Other outcomes included maternal depression, parenting self-efficacy, reported and observed parenting behaviour, and maternal ratings of child ADHD, oppositional defiant disorder (ODD) symptoms, and internalizing problems.

Results

Analysis of covariance (ANCOVA) compared the groups post intervention. Intervention mothers reported significantly less parenting stress, higher parenting self-esteem and use of more effective parenting strategies compared with controls, including a reduction in observed negative parenting, post intervention. These mothers also reported lower levels of child aggression and internalizing problems post intervention together with a trend (p < 0.05) toward reduced symptoms of inattention.

Conclusions

Well Parent Japan is an effective psychosocial intervention for parents of children with ADHD in Japan. The group format and the session content is well tolerated. This is the first randomized control trial (RCT) of a psychosocial intervention targeting ADHD in Japan.
Approximations of the Sum of States by Laplace’s Method for a System of Particles with a Finite Number of Energy Levels and Application to Limit Theorems
Authors: Łapiński Tomasz M.
Published: March 2020

We consider a generic system composed of a fixed number of particles distributed over a finite number of energy levels. We make only general assumptions about system’s properties and the entropy. System’s constraints other than fixed number of particles can be included by appropriate reduction of system’s state space. For the entropy we consider three generic cases. It can have a maximum in the interior of system’s state space or on the boundary. On the boundary we can have another two cases. There the entropy can increase linearly with increase of the number of particles and in the another case grows slower than linearly. The main results are approximations of system’s sum of states using Laplace’s method. Estimates of the error terms are also included. As an application, we prove the law of large numbers which yields the most probable state of the system. This state is the one with the maximal entropy. We also find limiting laws for the fluctuations. These laws are different for the considered cases of the entropy. They can be mixtures of Normal, Exponential and Discrete distributions. Explicit rates of convergence are provided for all the theorems.
Cognitive novelties, informational form, and structural-causal explanations
Authors: Buskell Andrew
Published: March 2020

Recent work has established a framework for explaining the origin of cognitive novelties—qualitatively distinct cognitive traits—in human beings. This niche construction approach argues that humans engineer epistemic environments in ways that facilitate the ontogenetic and phylogenetic development of such novelties. I here argue that attention to the organized relations between content-carrying informational vehicles, orinformational form, is key to a valuable explanatory strategy within this project, what I callstructural-causalexplanations. Drawing on recent work from Cecilia Heyes, and developing a case study around a novel mathematical capacity, I demonstrate how structural-causal explanations can contribute to the niche construction approach by underwriting the application of explanatory tools and generating new empirical targets.
Mode decomposition based deep learning model for multi-section traffic prediction
Authors: Pholsena Khouanetheva , Pan Li , Zheng Zhenpeng
Published: March 2020

Road traffic prediction plays a vital role in real-time traffic management of an intelligent transportation system (ITS). Many prediction models achieve fine results. However, most ignore the intrinsic characteristics of traffic parameter data and do not consider the spatiotemporal effects of road sections, which can reflect the situation of all road traffic. Therefore, multi-section traffic prediction is still an open problem. In this paper, empirical mode decomposition (EMD) is employed to decompose the information of traffic parameters into many intrinsic mode function (IMF) components, which represent the original road traffic information in periodic and random sequences. Then, by considering the superiority of deep learning in multi-dimensional data processing, which can handle the spatiotemporal effects, a prediction model based on a convolutional neural network (CNN) is proposed to achieve the prediction of periodic and random sequences, whose results are combined to obtain the final prediction. The dataset from the Caltrans Performance Measurement System is used to validate the model. The proposed prediction model is compared to several well-known models, such as PCA-BP, Lasso-BP, and standard CNN. Experiments show that the proposed prediction model achieves higher accuracy.
Alignment of forms in Spanish verbal inflection: the gang poner, tener, venir, salir, valer as a window into the nature of paradigmatic analogy and predictability
Authors: Herce Borja
Published: March 2020

The future and conditional forms ofvenir‘come’,tener‘have’ andponer‘put’ were characterized in Old Spanish by various alternatives (e.g.verné,vendré,verré,venréin the case of come.1SG.FUT) which originated through different sound changes taking place in different varieties. The victory ofvendréin contemporary Spanish could be seen simply as an inconsequential resolution of this competition of forms. Here I argue against such an interpretation. I will provide quantitative geographical and diachronic evidence which suggests that the adoption of the variantvendréis related to other apparently unconnected analogical changes (most notablyvalo>valgo‘be worth.1SG.PRES.IND’) in the history of the language. These two changes have conspired to align different morphological operations in a way that inflectional predictability is achieved from scratch. This development shows that predictability can be a major force in morphological change even between formally dissimilar morphological units and outside of the usual suspects the ‘morphomes’. The emergence of predictability networks like this one has important implications, touching on vital issues like segmentation, analogical change, the status of No-Blur, among others.
BBC05 with non-integer exponent and ambiguities in Nakajima yield surface calibration
Authors: Pilthammar Johan , Banabic Dorel , Sigvant Mats
Published: March 2020

Reliable sheet metal forming simulations depend on accurate descriptions of real process conditions. These conditions include material behavior, lubrication systems, tool deformations, press dynamics, and more. Research on material models is the most mature area for describing these conditions in a reliable way. Several advanced and flexible models exists. This study focuses on two versions of yield criteria for sheet materials that are assumed to follow the plane stress assumption: the BBC05 model with integer exponent and the BBC05 model with non-integer exponent. The literature has previously described the BBC05 model with integer exponent. This paper elaborates on a modified version with non-integer exponent that offers more flexibility in the mathematical description. Furthermore, it outlines the implementation of this material model and similar yield criteria as user subroutines in finite element software. As mathematical flexibility increases, it enables more physically correct material approximations. However, it also becomes more challenging to calibrate because of ambiguities due to a larger number of mathematical variables. These ambiguities is demonstrated by using a Nakajima test without lubrication during inverse modeling of parameters for the BBC05 model. It shows that it is impossible to accurately identify the physically correct combination of friction coefficient and the yield surface exponent, k, using strain distributions and punch force. It is suggested to use two Nakajima tests in the inverse modeling process where friction can be neglected due to testing conforming to ISO12004-2. One test that corresponds to equi-biaxial strain of the sheet, and one that corresponds to plane strain in the transverse direction of the sheet. By utilizing these samples in the inverse modeling it is possible to separate friction from the exponent k. A non-integer value of k is found to yield the most reliable prediction of strains and forces in the simulations, thereby also demonstrating the need of flexible yield surface models such as BBC05 with non-integer exponent, YLD2000, Vegter and more advanced yield criteria.
Clinical expert consensus document on quantitative coronary angiography from the Japanese Association of Cardiovascular Intervention and Therapeutics
Authors: Suzuki Nobuaki , Asano Taku , Nakazawa Gaku , Aoki Jiro , Tanabe Kengo , Hibi Kiyoshi , Ikari Yuji , Kozuma Ken
Published: March 2020

Quantitative coronary angiography (QCA) remains to play an important role in clinical trials and post-marketing surveillance related to the safety and efficacy of new PCI devices. In this document, the current standard methodology of QCA is summarized. In addition, its history, recent development and future perspectives are also reviewed.
The Cartesian Conception of the Development of the Mind and Its Neo-Aristotelian Alternative
Authors: Smit Harry
Published: March 2020

This article discusses some essential differences between the Cartesian and neo-Aristotelian conceptions of child development. It argues that we should prefer the neo-Aristotelian conception since it is capable of resolving the problems the Cartesian conception is confronted by. This is illustrated by discussing the neo-Aristotelian alternative to the Cartesian explanation of the development of volitional powers (the ideo-motor theory), and the neo-Aristotelian alternative to the Cartesian simulation theory and theory–theory account of the development of social cognition. The neo-Aristotelian conception is further elaborated by discussing how it differs from both behaviorism and cognitive neuroscience.
Hyperthyroxinemia with a non-suppressed TSH: how to confidently reach a diagnosis in this clinical conundrum
Authors: Timmons J. G. , Mukhopadhyay B.
Published: March 2020

Disorders of thyroid function are among the commonest referrals to endocrinology. While interpretation of thyroid function testing is usually straightforward, accurate interpretation becomes significantly more challenging when the parameters do not behave as would be expected in normal negative feedback. In such cases, uncertainty regarding further investigation and management arises. An important abnormal pattern encountered in clinical practice is that of high normal or raised free thyroxine (fT4) with inappropriately non-suppressed or elevated thyroid-stimulating hormone (TSH). In this short review using two clinical vignettes, we examine the diagnostic approach in such cases. A diagnostic algorithm is proposed to ensure that a definitive diagnosis is reached in these challenging cases.
An SNP based GWAS analysis of seed longevity in wheat
Authors: Rehman Arif Mian Abdur , Börner Andreas
Published: March 2020

Worldwide, ex situ genebanks are given the task to store seeds to prevent the danger of extinction of plant genetic resources. A regular monitoring of their germination capacity is central to any genebank and any drop in that beyond a certain threshold determines their regeneration cycle. Seed longevity varies among different species and is a quantitative trait. New molecular marker data covering hitherto empty genomic regions may provide new insights into the inheritance of this trait. Using genetic information of SNPs in two wheat panels, a total of 72 marker trait associations were discovered which could be confined to 24 quantitative trait loci (QTLs) based on marker proximity to each other. Among them, 13 QTLs are potentially novel. We also determined that with the pyramiding of favorable alleles, an increase of 12.8% in seed longevity could be achieved.
Veolia helps pharmaceutical manufacturer in South Africa meet strict standards of purity for process water
Authors: Atkinson Simon
Published: March 2020

In South Africa, a global speciality and branded multinational pharmaceutical company – with a presence in both emerging and developed markets – is installing a water purification system from Veolia Water Technologies as part of an expansion project at its plant based in Korsten, Port Elizabeth. This brief focus article takes a look at what is involved and how it will help the company meet strict standards of purity for process water.
RO-based system ensures alcohol-free beer retains its genuine flavour and original features
Authors: Atkinson Simon
Published: March 2020

Finnish brewery Laitilan Wirvoitusjuomatehdas Oy is employing the membrane-based AromaPlus de-alcoholisation system from GEA Group Aktiengesellschaft in part of the process it uses to produce alcohol-free beer. Used for the first time in Scandinavia, this technology ensures that the independent brewery's Laitilan Kukko beer retains its genuine flavour and original features, as this brief article explains.
Submerging polymer in water drastically improves its CO2 permeability whilst slightly enhancing its CO2 selectivity
Authors: Atkinson Simon
Published: March 2020

Work done by a team comprising researchers from North Carolina State University, the Norwegian University of Science and Technology and the Università di Bologna has found that it is possible to significantly enhance a midblock-sulfonated multiblock polymer membrane's ability to selectively remove carbon dioxide from gas mixtures by first submerging the material in liquid water. This article provides a summary of the findings.
Leather Shoes in Early Danish Cities: Choices of Animal Resources and Specialization of Crafts in Viking and Medieval Denmark
Authors: Brandt Luise Ørsted , Ebsen Jannie Amsgaard , Haase Kirstine
Published: March 2020

This article presents the findings of the minimally destructive biomolecular species identification method known as ZooMS (zooarchaeology by mass spectrometry) to identify the use and choices of resources for manufacturing leather shoes in urban contexts in Viking and medieval Denmark. Whereas parchment and historical skin samples have been previously analysed by ZooMS, the potential of the method is demonstrated here for archaeological, vegetable-tanned, and waterlogged leather from the eleventh to thirteenth-century Danish cities of Ribe, Odense, and Viborg. Sheep, goat, and cattle were used to produce shoes, with explicit choices of species for specific purposes. The selection seems to be largely based on the skins’ material properties, suggesting that functionality was more important than signalling. The urban environment is seen as promoting synergy among providers of resources, crafts, and customers.
Meditation effect in changing functional integrations across large-scale brain networks: Preliminary evidence from a meta-analysis of seed-based functional connectivity
Authors: Shen Yang-Qian , Zhou Hui-Xia , Chen Xiao , Castellanos Francisco Xavier , Yan Chao-Gan
Published: March 2020

Meditation is a type of mental training commonly applied in clinical settings and also practiced for general well-being. Brain functional connectivity (FC) patterns associated with meditation have revealed its brain mechanisms. However, the variety of FC methods applied has made it difficult to identify brain communication patterns associated with meditation. Here we carried out a coordinate-based meta-analysis to get preliminary evidence of meditation effects on changing brain network interactions. Fourteen seed-based, voxel-wise FC studies reported in 13 publications were reviewed; 10 studies with seeds in the default mode network (DMN) were meta-analyzed. Seed coordinates and the effect sizes in statistically significant regions were extracted, based on 170 subjects in meditation groups and 163 subjects in control groups. Seed-based d-mapping was used to analyze meditation versus control FC differences with DMN seeds. Meditation was associated with increased connectivity within DMN and between DMN and somatomotor network and with decreased connectivity between DMN and frontoparietal network (FPN) as well as ventral attention network (VAN). The pattern of decreased within-DMN FC and increased between-network FC (FPN and DAN with DMN) was more robust in highly experienced meditators compared to less experienced individuals. The identified neural network interactions may also promote meditation’s effectiveness in clinical interventions for treating physical and mental disorders.
Distributed Multi-Objective Algorithm for Preventing Multi-Ship Collisions at Sea
Authors: Li Jinxin , Wang Hongbo , Guan Zhiying , Pan Chong
Published: March 2020

Avoidance of collisions at sea is crucial to navigational safety. In this paper, we use a distributed algorithm to communicate the entire collision avoidance trajectory information for each ship. In each communication, we suggest a new improvement function considering safety and efficiency to identify the avoidance ship in each cycle. Considering the nonlinear collision avoidance trajectory of ships, a new method for calculating the degree of danger using a velocity obstacle algorithm is proposed. Therefore, in each communication, each ship considers the avoidance behaviours of other ships in planning its avoidance trajectory. Additionally, we combine bi-criterion evolution (BCE) and the ant lion optimiser to plan the entire collision avoidance path. Three scenarios are designed to demonstrate the performance of this method. The results show that the proposed method can find a suitable collision-free solution for all ships.
The History of Asteroid Family Identification
Authors: Knežević Zoran
Published: March 2020

In this paper the early history of search for asteroid groupings is briefly reviewed. Starting from the first attempts by Kirkwood, who managed to identify a number of asteroid pairs and triples with adjacent orbits, via the similar contributions of Tisserand and Mascart, we arrive to Hirayama and his discovery of asteroid families, marking the beginning of modern asteroid science.
Mapping of the asteroid families
Authors: Todorović Nataša
Published: March 2020

In this work we map one of the most populated regions in the main belt - the asteroid family Themis. Computed with a good choice of parameters, the map enables us to get a refined picture of the dynamics in the family, to reexamine the role of resonances therein, to understand better the distribution of asteroids inside the region and to identify dynamical pathways along which particles can drift away.
Role of the magnetic field on the formation of solar type stars
Authors: Valdivia Valeska , Maury Anaëlle J. , Hennebelle Patrick
Published: March 2020

Magnetic fields play a key role during the gravitational collapse of dense protostellar cores. In recent years mm and sub-mm observations of dust polarized emission have been used to unveil the morphology of the magnetic field, but this method relies on the assumption that non-spherical dust grains are well aligned with the magnetic field.

Using non-ideal MHD numerical simulations, we study the evolution of the magnetic field during the gravitational collapse. We use the state-of-the-art radiative transfer code POLARIS to compute the Stokes parameters and produce synthetic observations of mm/submm polarized dust emission. We compare the results obtained using the radiative torques (RAT) mechanism to the results obtained by assuming that grains are perfectly aligned to constrain how well polarized dust emission traces the magnetic field orientation.

The complexity of the magnetic field produces a mild depolarization. The depolarization observed in the inner regions is rather caused by a decrease of the dust alignment efficiency and it cannot be reproduced by just scaling down the polarisation degree obtained for a uniform efficiency. We find that the magnetic field orientation is well constrained by the polarized dust emission as long as its 3D topology remains organized.
Formation and Structure of Magnetized Protoplanetary Disks
Authors: Lizano Susana , Tapia Carlos
Published: March 2020

Protoplanetary disks are expected to form through the gravitational collapse of magnetized rotating dense cores. We discuss the structure and emission of models of accretion disks threaded by a poloidal magnetic field and irradiated by the central star, expected to form in this process (Shu et al. 2007; Lizano et al. 2016). The poloidal magnetic field produces sub-keplerian rotation of the gas which can accelerate planet migration (Adams et al. 2009). It can make the disk more stable against gravitational perturbations (Lizano et al. 2010). Also, the magnetic compression can reduce the disk scale height with respect to nonmagnetic disks. We find that the mass-to-flux ratio λ is a critical parameter: disks with a weaker magnetization (high values of λ) are denser and hotter and emit more at millimeter wavelengths than disks with a stronger magnetization (low values of λ). Applying these models to the millimeter observations of the disk around the young star HL Tau indicate the large grains are present at the external radii in order to reproduce the observed 7 mm emission that extends up to 100 AU (Tapia & Lizano 2017). In the near future, observations with ALMA and VLA will be able to determine the level of magnetization of protoplanetary disks, which will be important to understand their formation and evolution.
Magnetic field and accretion in EX Lup
Authors: Kóspál Á. , Donati J.-F. , Bouvier J. , Ábrahám P.
Published: March 2020

While the Sun is a quiet and well-balanced star now, during its first few million years it possessed a strong magnetic field and actively accreted material from its circumstellar environment. Theoretical models predict that under certain circumstances the interaction of a strongly magnetic star and its circumstellar disk may lead to short bursts of increased accretion onto the star (D’Angelo & Spruit 2012). Examples for this phenomenon may be the members of a group of young eruptive stars called EXors. Their prototype, EX Lup, had its historically largest outburst in 2008. Spectroscopic evidence suggests that the mass accretion proceeds through the same magnetospheric accretion channels both in quiescence and in outburst but with different mass flux (Sicilia-Aguilar et al. 2012). To characterize for the first time EX Lup’s magnetic field, we obtained spectropolarimetric monitoring for it with the CFHT/ESPaDOnS. We detected strong, poloidal magnetic field with a prominent cool polar cap and an accretion spot above it. We compared our results with numerical simulations, in order to check the applicability of the d’Angelo & Spruit model as an explanation of EX Lup’s accretion outbursts. If EX Lup is a good proxy for the proto-Sun, similar magnetic field-disk interactions and outbursts might have happened during the early evolution of the Solar System as well.
Magnetic massive stars in star forming regions
Authors: Hubrig Swetlana , Schöller Markus , Järvinen Silva P.
Published: March 2020

One idea for the origin of magnetic fields in massive stars suggests that the magnetic field is the fossil remnant of the Galactic ISM magnetic field, amplified during the collapse of the magnetised gas cloud. A search for the presence of magnetic fields in massive stars located in active sites of star formation led to the detection of rather strong magnetic fields in a few young stars. Future spectropolarimetric observations are urgently needed to obtain insights into the mechanisms that drive the generation of kG magnetic fields during high-mass star formation.
Sunspot and Group Number: Recent advances from historical data
Authors: Clette Frédéric , Vaquero José M. , Gallego María Cruz , Lefèvre Laure
Published: March 2020

Due to its unique 400-year duration, the sunspot number is a central reference for understanding the long-term evolution of solar activity and its influence on the Earth environment and climate. Here, we outline current data recovery work. For the sunspot number, we find historical evidence of a disruption in the source observers occurring in 1947–48. For the sunpot group number, recent data confirm the clear southern predominance of sunspots during the Maunder Minimum, while the umbra-penumbra ratio is similar to other epochs. For the Dalton minimum, newly recovered historical observations confirm a higher activity level than in a true Grand Minimum.
What can Observations of Comets Tell Us about the Solar Wind at the Maunder Minimum?
Authors: Zolotova N. V. , Sizonenko Y. V. , Vokhmyanin M. V. , Veselovsky I. S.
Published: March 2020

This paper discussed whether 17th Century observers left historical records of the plasma tails of comets that would be adequate to enable us to extract the physical parameters of the solar wind. The size of the aberration angle between a comet’s tail and its radius-vector defines the type of the tail: plasma or dust. We considered Bredikhin’s calculations of the parameters for 10 comet tails observed during the Maunder minimum (1645 – 1715). For those comets the angle between the tail’s axis and the radius-vector on average exceeded the value of 10° that is typical for dust tails. It was noted that visual observations of the ion tails of comets are very difficult to make owing to the spectral composition of their radiation, confirming the conclusion that observations of comet tails made in the 17th Century are not suitable for deriving past values of the physical parameters of the solar wind.
Angular Momentum – Conference Summary
Authors: Combes Francoise
Published: March 2020

Angular momentum (AM) is a key parameter to understand galaxy formation and evolution. AM originates in tidal torques between proto-structures at turn around, and from this the specific AM is expected to scale as a power-law of slope 2/3 with mass. However, subsequent evolution re-shuffles this through matter accretion from filaments, mergers, star formation and feedback, secular evolution and AM exchange between baryons and dark matter. Outer parts of galaxies are essential to study since they retain most of the AM and the diagnostics of the evolution. Galaxy IFU surveys have recently provided a wealth of kinematical information in the local universe. In the future, we can expect more statistics in the outer parts, and evolution at high z, including atomic gas with SKA.
Galaxy Evolution in the context of radial metallicity gradients
Authors: Tissera Patricia B.
Published: March 2020

The chemical abundances of the gas-phase and stellar components of disc galaxies are relevant to understand their formation and evolution. It has been shown that an inside-out disc formation yields negative chemical profiles. However, a large spread in metallicity gradients, including positive ones, has been reported by recent and more precise observations, suggesting the action of other physics processes such as gas outflows and inflows, radial migration, and mergers and interactions. Cosmological simulations that includes chemical models provide a tools to tackle the origin of the metallicity profiles and the action of those processes that might affect them as a function of time. I present a summary of the current state-of-knowledge from a numerical point of view and discuss the main results from the analysis of the EAGLE simulations.
Gas and stellar metallicity gradients in face-on disc galaxies
Authors: Sánchez-Blázquez P.
Published: March 2020

We present an analysis of the stellar and gaseous metallicity gradients in a sample of 260 disc galaxies from the CALIFA survey. The slope of the different components are compared with the main characteristics of the galaxies, such as mass, morphology, presence of a bar, or gas fraction.
SDSS-IV MaNGA: Testing the Metallicity Distribution across the Merging Sequence
Authors: Barrera-Ballesteros Jorge K. , Lin Li-hwai , Hsieh Bu-Ching , Pan Hsi-An , Sánchez Sebastian , Heckman Timothy
Published: March 2020

Interactions and mergers have been known as key scenarios to enhance global star formation rates and to lower the metal content of galaxies. However, little is known on how interactions affect the spatial distribution of gas metallicities. Thanks to the SDSS-IV MaNGA survey we are able to statistically constrain the impact of interactions across the optical distributions of galaxies. In this study, we compare the radial distribution of the ionized gas metallicity from a sample of 329 interacting objects – covering different interaction stages – with a statistical robust control sample. Our results suggest that galaxies close to coalesce tend to have flat, lower metallicities than non-interacting star-forming galaxies.
Supergiant Stars as Abundance Probes
Authors: Patrick L. R. , Evans C. J. , Davies B. , Kudritzki R.-P.
Published: March 2020

By compiling abundances from red and blue supergiants (SGs) within the Local Universe, I present the Mass-Metallicity relation (MZR) using stellar tracers, demonstrating the excellent internal consistency. Comparing this result with nebular tracers, those empirically calibrated to direct-method studies provide the most consistent results.
Nitrogen isotopic ratio across the Galaxy through observations of high-mass star-forming cores
Authors: Colzi L. , Fontani F. , Rivilla V. M. , Sánchez-Monge A. , Testi L. , Beltrán M. T. , Caselli P.
Published: March 2020

There is a growing evidence that our Sun was born in a rich cluster that also contained massive stars. Therefore, the study of high-mass star-forming regions is key to understand our chemical heritage. In fact, molecules found in comets, in other pristine Solar System bodies and in protoplanetary disks, are enriched in 15N, because they show a lower 14N/15N ratio (100-150) with respect to the value representative of the Proto-Solar Nebula (PSN, 441 ± 6), but the reasons of this enrichment cannot be explained by current chemical models. Moreover, the 14N/15N ratio is important because from it we can learn more about the stellar nucleosynthesis processes that produces both the elements. In this sense observations of star-forming regions are useful to constrain Galactic chemical evolution (GCE) models.
What the Milky Way bulge reveals about the initial metallicity gradients in the disc
Authors: Fragkoudi F. , Di Matteo P. , Haywood M. , Khoperskov S. , Gomez A. , Schultheis M. , Combes F. , Semelin B.
Published: March 2020

We examine the metallicity trends in the Milky Way (MW) bulge – using APOGEE DR13 data – and explore their origin by comparing two N-body models of isolated galaxies which develop a bar and a boxy/peanut (b/p) bulge. Both models have been proposed as scenarios for reconciling a disc origin of the MW bulge with a negative vertical metallicity gradient. The first is a superposition of co-spatial disc populations, different scaleheights and metallicities (with flat gradients) where the thick, metal-poor populations contribute significantly to the stellar mass budget in the inner galaxy. The second model is a single disc with an initial steep radial metallicity gradient which gets mapped by the bar into the b/p bulge in such a way that the vertical metallicity gradient of the MW bulge is reproduced – as shown already in previous works in the literature. As we show here, the latter model does not reproduce the positive longitudinal metallicity gradient of the inner disc, nor the metal-poor innermost regions seen in the data. The model with co-spatial thin and thick disc populations reproduces all the aforementioned trends. We therefore see that it is possible to reconcile a (primarily) disc origin for the MW bulge with the observed trends in metallicity by mapping the inner thin and thick discs of the MW into a b/p.
Synoptic maps in three wavelengths of the Chromospheric Telescope
Authors: Diercke Andrea , Denker Carsten
Published: March 2020

he Chromospheric Telescope (ChroTel) observes the entire solar disk since 2011 in three different chromospheric wavelengths: Hα, Ca ii K, and He i. The instrument records full-disk images of the Sun every three minutes in these different spectral ranges. The ChroTel observations cover the rising and decaying phase of solar cycle 24. We started analyzing the ChroTel time-series and created synoptic maps of the entire observational period in all three wavelength bands. The maps will be used to analyze the poleward migration of quiet-Sun filaments in solar cycle 24.
All sky photometric zero-points from stellar effective temperatures
Authors: Casagrande Luca
Published: March 2020

I use SkyMapper DR1.1 to explore the quality of its uvgriz photometry, and zero-points. I introduce a formalism to derive photometric zero-points across the sky by benchmarking against stars with well known effective temperatures, bypassing the need for absolute spectrophotometry.
WFC3/HST photometric calibration: color terms for the ultra-violet filters
Authors: Calamida Annalisa
Published: March 2020

Color term corrections for magnitudes measured on the UVIS2 relative to the UVIS1 detector of the WFC3 camera on board Hubble Space Telescope are needed for three ultra-violet filters, namely F218W, F225W, and F275W. The two WFC3 detectors have different quantum efficiencies in the ultra-violet regime (λ < 4,000 Å), resulting in different count rate ratios as a function of the spectral type of the source. In the worst case, for cool red sources measured on UVIS2, there is a magnitude offset relative to UVIS1 up to ∼ 0.08 mag, while the offset is negligible for hot (Teff ≳ 30,000 K) blue sources.
Overview of the OAD: Achievements, Challenges and Plans
Authors: McBride Vanessa , Venugopal Ramasamy
Published: March 2020

The Office of Astronomy for Development (OAD) aims to use astronomy, including its tools, practitioners and skills, to benefit society. The OAD, a joint project of the International Astronomical Union and the South African National Research Foundation, has the vision of using ‘Astronomy for a better world’. Since 2013, the OAD has funded more than 120 projects that use astronomy to address developmental issues as defined under the United Nations Sustainable Development Goals (SDG).
Independent Component Analysis and Parametric Approach for Source Separation in InSAR Time Series at Regional Scale: Application to the 2017–2018 Slow Slip Event in Guerrero (Mexico)
Authors: Maubant L. , Pathier E. , Daout S. , Radiguet M. , Doin M.‐P. , Kazachkina E. , Kostoglodov V. , Cotte N. , Walpersdorf A.
Published: March 2020

Separating different sources of signal in Interferometric Synthetic Aperture Radar (InSAR) studies over large areas is challenging, especially between the long‐wavelength changes of atmospheric conditions and tectonic deformations, both correlated to elevation. In this study, we focus on the 2017–2018 slow slip event (SSE) in the Guerrero state (Mexico) where (1) the permanent GPS network has a low spatial density (less than 30 stations in an area of 300 
 300 km) with uneven distribution; (2) the tropospheric phase delays can be as high as 20 cm of apparent ground displacements, with a complex temporal evolution; (3) the tested global weather models fail to correct interferograms with enough accuracy (with residual tropospheric signal higher than the tectonic signal); and (4) the surface displacement caused by the seismic cycle shows complex interactions between seismic sequences and aseismic events. To extract the SSE signal from Sentinel‐1 InSAR time series, we test two different approaches. The first (parametric method) consists of a least squares linear inversion, imposing a functional form for each deformation or atmospheric component. The second uses independent component analysis of the InSAR time series. We obtain time series maps of surface displacements along the radar line of sight associated with the SSE and validate these results with a comparison to GPS. Combining those two approaches, we propose a method to separate atmospheric delays and tectonic deformation on time series data not corrected from atmospheric delays. From the extracted ground deformation maps, we propose a first‐order slip inversion model at the subduction interface during this SSE.
Terrestrial CO2 Fluxes, Concentrations, Sources and Budget in Northeast China: Observational and Modeling Studies
Authors: Li Xiaolan , Hu Xiao‐Ming , Cai Changjie , Jia Qingyu , Zhang Yao , Liu Jingmiao , Xue Ming , Xu Jianming , Wen Rihong , Crowell Sean M. R.
Published: March 2020

CO2 fluxes and concentrations are not well understood in Northeast China, where dominant land surface types are mixed forest and cropland. Here, we analyzed the CO2 fluxes and concentrations using observations and the Weather Research and Forecasting model coupled with the Vegetation Photosynthesis and Respiration Model (WRF‐VPRM). We also used WRF‐VPRM outputs to examine CO2 transport/dispersion and budgets. Finally, we investigated the uncertainties of simulating CO2 fluxes related to four VPRM parameters (including maximum light use efficiency, photosynthetically active radiation half‐saturation value, and two respiration parameters) using off‐line ensemble simulations. The results indicated that mixed forests acted as a larger CO2 source and sink than rice paddies in 2016 due to a longer growth period and stronger ecosystem respiration, although measured minimum daily mean net ecosystem exchange (NEE) was smaller at rice paddy (−10 μmol·m‐2·s‐1) than at mixed forest (−6.5 μmol·m‐2·s‐1) during the growing season (May–September). The monthly fluctuation of column‐averaged CO2 concentrations (XCO2) exceeded 10 ppm in Northeast China during 2016. The large summertime biogenic sinks offset about 70% of anthropogenic contribution of XCO2 in this region. WRF‐VPRM modeling successfully captured seasonal and episodic variations of NEE and CO2 concentrations; however, NEE in mixed forest was overestimated during daytime, mainly due to the uncertainties of VPRM parameters, especially maximum light use efficiency. These findings suggest that the WRF‐VPRM modeling framework will provide greater understanding of the natural and anthropogenic contributions to the carbon cycle in China, especially after calibration of parameters that control biogenic fluxes.