bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vacuolar sucrose homeostasis is critical for plant development, seed properties, and night-time survival in Arabidopsis
Authors: Vu Duc Phuong , Martins Rodrigues Cristina , Jung Benjamin , Meissner Garvin , Klemens Patrick A W , Holtgräwe Daniela , Fürtauer Lisa , Nägele Thomas , Nieberl Petra , Pommerrenig Benjamin , Neuhaus H Ekkehard 
Published: April 2020

AbstractMost cellular sucrose is present in the cytosol and vacuoles of plant cells; however, little is known about the effect of this sucrose compartmentation on plant properties. Here, we examined the effects of altered intracellular sucrose compartmentation in Arabidopsis thaliana leaves by heterologously expressing the sugar beet (Beta vulgaris) vacuolar sucrose loader BvTST2.1 and by generating lines with reduced vacuolar invertase activity (amiR vi1-2). Heterologous expression of BvTST2.1 led to increased monosaccharide levels in leaves, whereas sucrose levels remained constant, indicating that vacuolar invertase activity in mesophyll vacuoles exceeds sucrose uptake. This notion was supported by analysis of tobacco (Nicotiana benthamiana) leaves transiently expressing BvTST2.1 and the invertase inhibitor NbVIF. However, sucrose levels were strongly elevated in leaf extracts from amiR vi1-2 lines, and experiments confirmed that sucrose accumulated in the corresponding vacuoles. The amiR vi1-2 lines exhibited impaired early development and reduced seed weight. When germinated in the dark, amiR vi1-2 seedlings were less able to convert sucrose into monosaccharides than the wild type. Cold temperatures strongly down-regulated both VI genes, but the amiR vi1-2 lines showed normal frost tolerance. These observations indicate that increased vacuolar sucrose levels fully compensate for the effects of low monosaccharide concentrations on frost tolerance.
A transition from parabolic to conical shape as a common effect in nearby AGN jets
Authors: Kovalev Y Y , Pushkarev A B , Nokhrina E E , Plavin A V , Beskin V S , Chernoglazov A V , Lister M L , Savolainen T 
Published: April 2020

ABSTRACT
Observational studies of collimation in jets in active galactic nuclei (AGN) are a key to understanding their formation and acceleration processes. We have performed an automated search for jet shape transitions in a sample of 367 AGN using VLBA data at 15 and 1.4 GHz. This search has found 10 out of 29 nearby jets at redshifts z &lt; 0.07 with a transition from a parabolic to conical shape, while the full analysed sample is dominated by distant AGN with a typical z ≈ 1. The ten AGN are UGC 00773, NGC 1052, 3C 111, 3C 120, TXS 0815−094, Mrk 180, PKS 1514+00, NGC 6251, 3C 371, and BL Lac. We conclude that the geometry transition may be a common effect in AGN jets. It can be observed only when sufficient linear resolution is obtained. Supplementing these results with previously reported shape breaks in the nearby AGN 1H 0323+342 and M87, we estimate that the break occurs at 105–106 gravitational radii from the nucleus. We suggest that the jet shape transition happens when the bulk plasma kinetic energy flux becomes equal to the Poynting energy flux, while the ambient medium pressure is assumed to be governed by Bondi accretion. In general, the break point may not coincide with the Bondi radius. The observational data support our model predictions on the jet acceleration and properties of the break point.
Bounds on WIMP dark matter from galaxy clusters at low redshift
Authors: Tan Xiuhui , Colavincenzo Manuel , Ammazzalorso Simone 
Published: April 2020

Abstract
In this work we study the cross-correlation between Fermi-LAT diffuse γ-ray maps and galaxy cluster catalogues in order to search for a diffuse dark matter signal. We employ an accurate estimation of the error covariance matrix and we select 4 galaxy cluster catalogues at low-redshift 0 &lt; z &lt; 0.2 with large-halo mass M500 &gt; 1013M⊙ including infrared, optical and X-rays wavebands. We consider weakly interacting massive particle (WIMP) dark matter with 100% branching ratios into τ+τ−, $b\bar{b}$, W+W− and μ+μ−. No evidence for a WIMP dark matter signal is identified, and we derive competitive bounds. The WIMP thermally averaged cross section is excluded at 95% C.L. for dark matter masses below 20 GeV and annihilation in the τ+τ− channel.
A census of main-sequence interactions in the Multiple Star Catalogue
Authors: Hamers Adrian S 
Published: April 2020

ABSTRACT
Statistics of hierarchical systems containing three or more stars are continuously improving. The Multiple Star Catalogue (MSC) is currently the most comprehensive catalogue of multiple-star systems and contains component masses, orbital periods, and additional information. The systems in the MSC are interesting for several reasons, including the long-term dynamical evolution of few-body systems. Although the secular evolution of triples and quadruples has been explored before, a systematic study of the systems in the MSC including also quintuples and sextuples has not been carried out. Here, we explore the main-sequence (MS) evolution of stars from the MSC based on approximately 2 × 105 secular dynamical integrations. We estimate statistical probabilities for strong interactions during the MS such as tidal evolution and mass transfer, and the onset of dynamical instability. Depending on the assumed model for the unknown orbital elements, we find that the fraction of non-interacting systems is largest for triples (∼0.9), and decreases to ∼0.6–0.8 for sextuples. The fraction of strong interactions increases from ∼0.1 to ∼0.2 from triples to sextuples, and the fraction of dynamically unstable systems increases from ∼0.001 to ∼0.1–0.2. The larger fractions of strong interactions and dynamical instability in systems with increasing multiplicity can be attributed to increasingly complex secular evolution in these systems. Our results indicate that a significant fraction of high-multiplicity systems interact or become dynamically unstable already during the MS, with an increasing importance as the number of stars increases.
Statistics and properties of emission-line regions in the local volume dwarf galaxies
Authors: Karachentsev I D , Kaisin S S 
Published: April 2020

ABSTRACT
We used the H α images  from a large sample of nearby late-type dwarf galaxies to investigate properties of their emission structure. The sample consists of 300 galaxies of the irregular (Irr), Magellanic irregular (Im), blue compact dwarf (BCD), and transition (Tr) types situated within a distance of 11 Mpc. In each galaxy, we indicated the number of compact H ii regions, the presence of bubble-like or filament-like structures, the presence of a faint diffuse emission, and a sign of the global burst. The larger the luminosity of a galaxy, the greater number of compact H ii sources in it. The integral and specific star formation rates (SFRs) of the dwarf increase steeply with the increase of the number of H ii regions showing the evidence of the epidemic character of the star formation process. The dwarf galaxies with emission-line bubbles, or filaments, or signs of the global star formation burst have approximately the same hydrogen-mass-to-luminosity ratio as that of the whole sample objects. However, their mean SFR is significantly higher than that of other galaxies in the sample. Emission bubble-like structures are found in the nearby dwarfs with a frequency of one case per four to five galaxies. Their linear diameters are close to those expected for supernova remnants. The mean specific SFR for the nearby late-type dwarfs is close to the Hubble parameter, H0 = −10.14 dex (yr)−1, consistent with the sluggish cosmic star formation history of galaxies of this kind.
Refracting into ultra-diffuse galaxy NGC 1052-DF2 by passing near the centre of NGC 1052
Authors: Huo Ran 
Published: April 2020

ABSTRACT
The recent observation of the ultra-diffuse galaxy NGC 1052-DF2 shows a galaxy may lack dark matter, which becomes a challenge to the standard structure formation theory. Here, we show that such phenomena can be a natural consequence if the NGC 1052-DF2 had experienced a single passage within a few kpc to the centre of the galaxy NGC 1052. The tidal effect of NGC 1052 in the encounter will heat the NGC 1052-DF2, and stretch the previous dwarf galaxy significantly into its current size. The relative lack of dark matter in the observed region is a natural consequence of the dark matter limited total amount in the corresponding small central region before the encounter, together with a systematic underestimation of the trace mass estimator method during revirialization after the encounter. The observed flat distribution of the ultra-diffuse galaxy can be reproduced with a cored initial star profile, which is a major improvement compared with the previous work. Our results show no need for introducing any new physical mechanism, as well as an alternative origin of an ultra-diffuse galaxy without repeated pericentre passage.
Artefacts of circumpolar cartography in radio pulsar polarization
Authors: Dyks J 
Published: April 2020

ABSTRACT
Single-pulse data on radio pulsar polarization are traditionally presented in the form of two-dimensional grey-scale patterns with the pulse longitude and polarization angle (PA) on the horizontal and vertical axis, respectively. Such diagrams reveal several enigmatic polarization effects: (1) bifurcations and loops of PA curve under central pulse components, (2) vertical spread of flux at all PA values, (3) exchange of power content between PA tracks of two orthogonal polarization modes (OPMs), and (4) peripherically flat PA swings that span more than 180 deg. It is shown that all these phenomena result from passage of observed polarization state near the pure-V pole of Poincaré sphere. Much of their complexity results from cartographic transformation from Poincaré sphere to the longitude–PA plane. An odd number of near-pole passages produce apparent replacement of OPM power in the profile wings, although the same amount of flux keeps staying in each modal patch on the Poincaré sphere. The fitting of pulsar PA curves should therefore allow for transitions between the primary (strong) and secondary (weak) PA tracks. The Stokes space (or Poincaré sphere) representation of pulsar polarization data contains crucial polarization information and needs to accompany the traditional viewing if the published figures are to be fully useful for interpretation.
Discovering the most elusive radio relic in the sky: diffuse shock acceleration caught in the act?
Authors: Locatelli Nicola T , Rajpurohit Kamlesh , Vazza Franco , Gastaldello Fabio , Dallacasa Daniele , Bonafede Annalisa , Rossetti Mariachiara , Stuardi Chiara , Bonassieux Etienne , Brunetti Gianfranco , Brüggen Marcus , Shimwell Timothy 
Published: April 2020

ABSTRACT
The origin of radio relics is usually explained via diffusive shock acceleration (DSA) or re-acceleration of electrons at/from merger shocks in galaxy clusters. The case of acceleration is challenged by the low predicted efficiency of low Mach number merger shocks, unable to explain the power observed in most radio relics. In this letter, we present the discovery of a new giant radio relic around the galaxy cluster Abell 2249 ($z$ = 0.0838) using Low-Frequency Array (LOFAR). It is special since it has the lowest surface brightness of all known radio relics. We study its radio and X-ray properties combining LOFAR data with uGMRT, JVLA, and XMM. This object has a total power of $L_{1.4\rm\, GHz}=4.1\pm 0.8 \times 10^{23}$ W Hz−1 and integrated spectral index α = 1.15 ± 0.23. We infer for this radio relic a lower bound on the magnetization of $B\ge 0.4\, \mu$G, a shock Mach number of $\mathcal {M}\approx 3.79$, and a low acceleration efficiency consistent with DSA. This result suggests that a missing population of relics may become visible, thanks to the unprecedented sensitivity of the new generation of radio telescopes.
Evolution of Sequence-Diverse Disordered Regions in a Protein Family: Order within the Chaos
Authors: Shafee Thomas , Bacic Antony , Johnson Kim 
Published: April 2020

Abstract
Approaches for studying the evolution of globular proteins are now well established yet are unsuitable for disordered sequences. Our understanding of the evolution of proteins containing disordered regions therefore lags that of globular proteins, limiting our capacity to estimate their evolutionary history, classify paralogs, and identify potential sequence–function relationships. Here, we overcome these limitations by using new analytical approaches that project representations of sequence space to dissect the evolution of proteins with both ordered and disordered regions, and the correlated changes between these. We use the fasciclin-like arabinogalactan proteins (FLAs) as a model family, since they contain a variable number of globular fasciclin domains as well as several distinct types of disordered regions: proline (Pro)-rich arabinogalactan (AG) regions and longer Pro-depleted regions.
Sequence space projections of fasciclin domains from 2019 FLAs from 78 species identified distinct clusters corresponding to different types of fasciclin domains. Clusters can be similarly identified in the seemingly random Pro-rich AG and Pro-depleted disordered regions. Sequence features of the globular and disordered regions clearly correlate with one another, implying coevolution of these distinct regions, as well as with the N-linked and O-linked glycosylation motifs. We reconstruct the overall evolutionary history of the FLAs, annotated with the changing domain architectures, glycosylation motifs, number and length of AG regions, and disordered region sequence features. Mapping these features onto the functionally characterized FLAs therefore enables their sequence–function relationships to be interrogated. These findings will inform research on the abundant disordered regions in protein families from all kingdoms of life.
Pervasive Phenotypic Impact of a Large Nonrecombining Introgressed Region in Yeast
Authors: Brion Christian , Caradec Claudia , Pflieger David , Friedrich Anne , Schacherer Joseph 
Published: April 2020

Abstract
To explore the origin of the diversity observed in natural populations, many studies have investigated the relationship between genotype and phenotype. In yeast species, especially in Saccharomyces cerevisiae, these studies are mainly conducted using recombinant offspring derived from two genetically diverse isolates, allowing to define the phenotypic effect of genetic variants. However, large genomic variants such as interspecies introgressions are usually overlooked even if they are known to modify the genotype–phenotype relationship. To have a better insight into the overall phenotypic impact of introgressions, we took advantage of the presence of a 1-Mb introgressed region, which lacks recombination and contains the mating-type determinant in the Lachancea kluyveri budding yeast. By performing linkage mapping analyses in this species, we identified a total of 89 loci affecting growth fitness in a large number of conditions and 2,187 loci affecting gene expression mostly grouped into two major hotspots, one being the introgressed region carrying the mating-type locus. Because of the absence of recombination, our results highlight the presence of a sexual dimorphism in a budding yeast for the first time. Overall, by describing the phenotype–genotype relationship in the Lachancea kluyveri species, we expanded our knowledge on how genetic characteristics of large introgression events can affect the phenotypic landscape.
Pby1 is a direct partner of the Dcp2 decapping enzyme
Authors: Charenton Clément , Gaudon-Plesse Claudine , Back Régis , Ulryck Nathalie , Cosson Loreline , Séraphin Bertrand , Graille Marc 
Published: April 2020

AbstractMost eukaryotic mRNAs harbor a characteristic 5′ m7GpppN cap that promotes pre-mRNA splicing, mRNA nucleocytoplasmic transport and translation while also protecting mRNAs from exonucleolytic attacks. mRNA caps are eliminated by Dcp2 during mRNA decay, allowing 5′-3′ exonucleases to degrade mRNA bodies. However, the Dcp2 decapping enzyme is poorly active on its own and requires binding to stable or transient protein partners to sever the cap of target mRNAs. Here, we analyse the role of one of these partners, the yeast Pby1 factor, which is known to co-localize into P-bodies together with decapping factors. We report that Pby1 uses its C-terminal domain to directly bind to the decapping enzyme. We solved the structure of this Pby1 domain alone and bound to the Dcp1–Dcp2–Edc3 decapping complex. Structure-based mutant analyses reveal that Pby1 binding to the decapping enzyme is required for its recruitment into P-bodies. Moreover, Pby1 binding to the decapping enzyme stimulates growth in conditions in which decapping activation is compromised. Our results point towards a direct connection of Pby1 with decapping and P-body formation, both stemming from its interaction with the Dcp1–Dcp2 holoenzyme.
Regenerating tubular epithelial cells of the kidney
Authors: Stamellou Eleni , Leuchtle Katja , Moeller Marcus J 
Published: April 2020

Abstract
Acute tubular injury accounts for the most common intrinsic cause for acute kidney injury. Normally, the tubular epithelium is mitotically quiescent. However, upon injury, it can show a brisk capacity to regenerate and repair. The scattered tubular cell (STC) phenotype was discovered as a uniform reaction of tubule cells triggered by injury. The STC phenotype is characterized by a unique protein expression profile, increased robustness during tubular damage and increased proliferation. Nevertheless, the exact origin and identity of these cells have been unveiled only in part. Here, we discuss the classical concept of renal regeneration. According to this model, surviving cells dedifferentiate and divide to replace neighbouring lost tubular cells. However, this view has been challenged by the concept of a pre-existing and fixed population of intratubular progenitor cells. This review presents a significant body of previous work and animal studies using lineage-tracing methods that have investigated the regeneration of tubular cells. We review the experimental findings and discuss whether they support the progenitor hypothesis or the classical concept of renal tubular regeneration. We come to the conclusion that any proximal tubular cell may differentiate into the regenerative STC phenotype upon injury thus contributing to regeneration, and these cells differentiate back into tubular cells once regeneration is finished.
Food additive emulsifiers: a review of their role in foods, legislation and classifications, presence in food supply, dietary exposure, and safety assessment
Authors: Cox Selina , Sandall Alicia , Smith Leanne , Rossi Megan , Whelan Kevin 
Published: April 2020

AbstractFood additive intakes have increased with the increase in “ultra-processed” food consumption. Food additive emulsifiers have received particular research attention in recent years due to preliminary evidence of adverse gastrointestinal and metabolic health effects. In this review, the use of emulsifiers as food additives is discussed, and the current estimations of exposure to, and safety of, emulsifiers are critically assessed. Food additive emulsifier research is complicated by heterogeneity in additives considered to be emulsifiers and labelling of them on foods globally. Major limitations exist in estimating food additive emulsifier exposure, relating predominantly to a lack of available food occurrence and concentration data. Development of brand-specific food additive emulsifier databases are crucial to accurately estimating emulsifier exposure. Current research on the health effects of food additive emulsifiers are limited to in vitro and murine studies and small, acute studies in humans, and future research should focus on controlled human trials of longer duration.
Agency as Art
Authors: Nguyen C. Thi 
Published: April 2020

Abstract
Games are a distinctive art form. A game isn’t merely a designed environment. A game tells its players what abilities to use and what goals to pursue. A game, in other words, specifies a form of agency. This chapter proposes that games are the art form that works in the medium of agency. And to play a game, players temporarily submerge themselves in an alternate agency. This chapter focuses on what we learn, from the fact that we play games, about our motivational capacities. In many kinds of game playing, we are not playing to win. We are, instead, taking on a temporary interest in winning, for the sake of the struggle. Game playing is a motivational inversion of ordinary practical life. And we are beings that can invert our motivations, and take on temporary and disposable ends, for the sake of having a valuable struggle.
The Distance in the Game
Authors: Nguyen C. Thi 
Published: April 2020

Abstract
Games offer an aesthetics of self-reflection, where players appreciate the aesthetic qualities in their own activities. They are part of what we can call the process arts, where the audience is supposed to appreciate the aesthetic qualities of their own activity, in response to an artifact. This chapter provides an account of the process arts in general, and situates games inside them. The process arts are contrasted with the more familiar object arts, where the audience is supposed to appreciate the aesthetic qualities of the artifact itself. The process arts offer a greater distance between artist and effect. Thus, the medium of games can be understood by thinking about the unique challenges it presents to the artist. The chapter focuses on the characteristic challenge of the medium of agency: the game designer must cope with agential distance. Game designers must achieve their aesthetic effects through the agent of the player, making room for the player’s choices, creativity, and variable skill. But game designers have a special tool for coping with that agential distance. They can designate the basic shape of the player’s agency in the game.
Games as Social Transformation
Authors: Nguyen C. Thi 
Published: April 2020

Abstract
Games work not only in the medium of agency, but also in the medium of sociality. This chapter studies how games create new patterns of social relationships, and how this permits games to effect a special kind of moral transformation. In games, we can transform competition into cooperation. Games are a designed environment, where we can unleash our most competitive instincts, and be assured that they will be transformed by the gaming context into an interesting struggle for our opponents. The chapter shows, then, that games can give us experiences of alternate forms of society. They are a kind of social art; that is, they transfigure our social arrangements for artistic purposes. Most contemporary social art practices, however, avoid specifying rules and goals for audience participation, preferring to leave the audience free to do as they please. Games show us that using rules and goals can actually help further the transformational goals of social art.
Origins (1939–1962)
Authors: Sewell Amanda 
Published: April 2020

Abstract
This chapter focuses on Wendy Carlos’s life from her 1939 birth in Pawtucket, Rhode Island, to her graduation from Brown University in 1962. From her earliest days, Carlos was innovative and resourceful. She built equipment out of spare parts, hammered her piano into different tuning systems, and taught herself harmony and counterpoint from library books. Carlos knew from childhood that her gender identity made her a target for ridicule and violence, so she retreated into a solitary world of electronic music. Under the guidance of Wesley Nyborg at Brown University, Carlos created a major that blended physics and music.