bluuebunny/crossref_metadata_2025_split huggingface dataset:
Colourful cones: how did flower colour first evolve?
Authors: Rudall Paula J 
Published: October 2019

AbstractAngiosperms that are biotically pollinated typically produce flowers with bright and contrasting colours that help to attract pollinators and hence contribute to the reproductive success of the species. This colourful array contrasts with the much less multicoloured reproductive structures of the four living gymnosperm lineages, which are mostly wind pollinated, though cycads and Gnetales are predominantly pollinated by insects that feed on surface fluids from the pollination drops. This review examines the possible evolutionary pathways and cryptic clues for flower colour in both living and fossil seed plants. It investigates how the ancestral flowering plants could have overcome the inevitable trade-off that exists between attracting pollinators and minimizing herbivory, and explores the possible evolutionary and biological inferences from the colours that occur in some living gymnosperms. The red colours present in the seed-cone bracts of some living conifers result from accumulation of anthocyanin pigments; their likely primary function is to help protect the growing plant tissues under particular environmental conditions. Thus, the visual cue provided by colour in flower petals could have first evolved as a secondary effect, probably post-dating the evolution of bee colour vision but occurring before the subsequent functional accumulation of a range of different flower pigments.
H i observations of IC 10 with the DRAO synthesis telescope
Authors: Namumba B , Carignan C , Foster T , Deg N 
Published: October 2019

ABSTRACT
H i observations of the nearby blue compact dwarf galaxy IC 10 obtained with the Dominion Radio Astrophysical Observatory synthesis telescope, for a total integration of ∼1000 h, are presented. We confirm the NW faint 21 cm H i emission feature discovered in Green Bank Telescope (GBT) observations. The H i feature has an H i mass of 4.7 × 105 M⊙, which is only ∼0.6 ${{\ \rm per\ cent}}$ of the total H i mass of the galaxy (7.8 × 107 M⊙). In the inner disc, the rotation curve of IC 10 rises steeply, then flattens until the last point where it rises again, with a maximum velocity of 30 km s−1. Based on our mass models, the kinematics of the inner disc of IC 10 can be described without the need of a dark matter halo. However, this does not exclude the possible presence of dark matter on a larger scale. It is unlikely that the disturbed features seen in the outer H i disc of IC 10 are caused by an interaction with M 31. Features seen from our simulations are larger and at lower surface density than can be reached by current observations. The higher velocity dispersions seen in regions where several distinct H i features meet with the main core of IC 10 suggest that there is ongoing accretion.
Clustering clusters: unsupervised machine learning on globular cluster structural parameters
Authors: Pasquato Mario , Chung Chul 
Published: October 2019

ABSTRACT
Globular clusters (GCs) have historically been subdivided in either two (disc/halo) or three (disc/inner-halo/outer-halo) groups based on their orbital, chemical, and internal physical properties. The qualitative nature of this subdivision makes it impossible to determine whether the natural number of groups is actually two, three, or more. In this paper we use cluster analysis on the (log M, log σ0, log Re, [Fe/H], log |Z|) space to show that the intrinsic number of GC groups is actually either k = 2 or k = 3, with the latter being favoured albeit non-significantly. In the k = 2 case, the Partitioning Around Medoids (PAM) clustering algorithm recovers a metal-poor halo GC group and a metal-rich disc GC group. With k = 3 the three groups can be interpreted as disc/inner-halo/outer-halo families. For each group we obtain a medoid, i.e. a representative element (NGC 6352, NGC 5986, and NGC 5466 for the disc, inner halo, and outer halo, respectively), and a measure of how strongly each GC is associated with its group, the so-called silhouette width. Using the latter, we find a correlation with age for both disc and outer halo GCs where the stronger the association of a GC with the disc (outer halo) group, the younger (older) it is. Our findings are aligned with previous work based on very different approaches, such as cladistic analysis, suggesting that the grouping we obtain is quite robust and represents some genuine underlying physical subdivision of GCs. We provide a catalogue where we list the assigned group for each GC.
Magnification, dust and time-delay constraints from the first resolved strongly lensed Type Ia supernova iPTF16geu
Authors: Dhawan S , Johansson J , Goobar A , Amanullah R , Mörtsell E , Cenko S B , Cooray A , Fox O , Goldstein D , Kalender R , Kasliwal M , Kulkarni S R , Lee W H , Nayyeri H , Nugent P , Ofek E , Quimby R 
Published: October 2019

Abstract
We report lensing magnifications, extinction, and time-delay estimates for the first resolved, multiply-imaged Type Ia supernova iPTF16geu, at z = 0.409, using Hubble Space Telescope (HST) observations in combination with supporting ground-based data. Multi-band photometry of the resolved images provides unique information about the differential dimming due to dust in the lensing galaxy. Using HST and Keck AO reference images taken after the SN faded, we obtain a total lensing magnification for iPTF16geu of $\mu = 67.8^{+2.6}_{-2.9}$, accounting for extinction in the host and lensing galaxy. As expected from the symmetry of the system, we measure very short time-delays for the three fainter images with respect to the brightest one: -0.23 ± 0.99, -1.43 ± 0.74 and 1.36 ± 1.07 days. Interestingly, we find large differences between the magnifications of the four supernova images, even after accounting for uncertainties in the extinction corrections: $\Delta m_1 = -3.88^{+0.07}_{-0.06}$, $\Delta m_2 = -2.99^{+0.09}_{-0.08}$, $\Delta m_3 = -2.19^{+0.14}_{-0.15}$ and $\Delta m_4 = -2.40^{+0.14}_{-0.12}$ mag, discrepant with model predictions suggesting similar image brightnesses. A possible explanation for the large differences is gravitational lensing by substructures, micro- or millilensing, in addition to the large scale lens causing the image separations. We find that the inferred magnification is insensitive to the assumptions about the dust properties in the host and lens galaxy.
Radio spectral properties of cores and extended regions in blazars in the MHz regime
Authors: d’Antonio D , Giroletti M , Giovannini G , Maini A 
Published: October 2019

ABSTRACT
Low-frequency radio surveys allow in-depth studies and new analyses of classes of sources that were previously known and characterized only in other bands. In recent years, low radio frequency observations of blazars have become available as a result of new surveys, such as the GaLactic and Extragalactic All-sky Murchison Widefield Array (MWA) survey (GLEAM). We search for gamma-ray blazars in a low-frequency (ν &lt; 240 MHz) survey, to characterize the spectral properties of the spatial components. We cross-correlate GLEAM with the fourth catalogue of active galactic nuclei (4LAC) detected by the Fermi satellite. This improves on previous works by using a low-frequency catalogue that is wider and deeper, with a better spectral coverage and the latest and most sensitive gamma-ray source list. Compared with a previous study based on the commissioning survey, the detection rate increased from 35 to 70 per cent. We include data from the Australia Telescope 20-GHz (AT20G) survey in order to extract high-frequency high-angular resolution information about the radio cores of blazars. We find low radio frequency counterparts for 1274 out of 1827 blazars in the range of 72–231 MHz. Blazars have flat spectra at the ∼100-MHz regime, with a mean spectral index α = −0.44 ± 0.01 (assuming Sν ∝ να). Low synchrotron peaked objects have a flatter spectrum than high synchrotron peaked objects. Low frequency radio and gamma-ray emissions show a significant but scattered correlation. The ratio between lobe and core radio emission in gamma-ray blazars is smaller than previously estimated.
Differential rotation in convective envelopes: constraints from eclipsing binaries
Authors: Jermyn Adam S , Tayar Jamie , Fuller Jim 
Published: October 2019

ABSTRACT
Over time, tides synchronize the rotation periods of stars in a binary system to the orbital period. However, if the star exhibits differential rotation, then only a portion of it can rotate at the orbital period, so the rotation period at the surface may not match the orbital period. The difference between the rotation and orbital periods can therefore be used to infer the extent of the differential rotation. We use a simple parametrization of differential rotation in stars with convective envelopes in circular orbits to predict the difference between the surface rotation period and the orbital period. Comparing this parametrization to observed eclipsing binary systems, we find that in the surface convection zones of stars in short-period binaries there is very little radial differential rotation, with |r∂rln Ω| &lt; 0.02. This holds even for longer orbital periods, though it is harder to say which systems are synchronized at long periods, and larger differential rotation is degenerate with asynchronous rotation.
Weak lensing shear estimation beyond the shape-noise limit: a machine learning approach
Authors: Springer Ofer M , Ofek Eran O , Weiss Yair , Merten Julian 
Published: October 2019

Abstract
Weak lensing shear estimation typically results in per galaxy statistical errors significantly larger than the sought after gravitational signal of only a few percent. These statistical errors are mostly a result of shape-noise — an estimation error due to the diverse (and a-priori unknown) morphology of individual background galaxies. These errors are inversely proportional to the limiting angular resolution at which localized objects, such as galaxy clusters, can be probed with weak lensing shear. In this work we report on our initial attempt to reduce statistical errors in weak lensing shear estimation using a machine learning approach — training a multi-layered convolutional neural network to directly estimate the shear given an observed background galaxy image. We train, calibrate and evaluate the performance and stability of our estimator using simulated galaxy images designed to mimic the distribution of HST observations of lensed background sources in the CLASH galaxy cluster survey. Using the trained estimator, we produce weak lensing shear maps of the cores of 20 galaxy clusters in the CLASH survey, demonstrating an RMS scatter reduced by approximately 26% when compared to maps produced with a commonly used shape estimator. This is equivalent to a survey speed enhancement of approximately 60%. However, given the non-transparent nature of the machine learning approach, this result requires further testing and validation. We provide python code to train and test this estimator on both simulated and real galaxy cluster observations. We also provide updated weak lensing catalogues for the 20 CLASH galaxy clusters studied.
Searching for eccentricity: signatures of dynamical formation in the first gravitational-wave transient catalogue of LIGO and Virgo
Authors: Romero-Shaw Isobel M , Lasky Paul D , Thrane Eric 
Published: October 2019

ABSTRACT
Binary black holes are thought to form primarily via two channels: isolated evolution and dynamical formation. The component masses, spins, and eccentricity of a binary black hole system provide clues to its formation history. We focus on eccentricity, which can be a signature of dynamical formation. Employing the spin-aligned eccentric waveform model seobnre, we perform Bayesian inference to measure the eccentricity of binary black hole merger events in the first gravitational-wave transient catalogue of LIGO and Virgo. We find that all of these events are consistent with zero eccentricity. We set upper limits on eccentricity ranging from 0.02 to 0.05 with 90  per cent confidence at a reference frequency of $10\, {\rm Hz}$. These upper limits do not significantly constrain the fraction of LIGO–Virgo events formed dynamically in globular clusters, because only $\sim 5{{\ \rm per\ cent}}$ are expected to merge with measurable eccentricity. However, with the gravitational-wave transient catalogue set to expand dramatically over the coming months, it may soon be possible to significantly constrain the fraction of mergers taking place in globular clusters using eccentricity measurements.
Probing cosmology and cluster astrophysics with multiwavelength surveys – I. Correlation statistics
Authors: Shirasaki Masato , Lau Erwin T , Nagai Daisuke 
Published: October 2019

ABSTRACT
Upcoming multiwavelength astronomical surveys will soon discover all massive galaxy clusters and provide unprecedented constraints on cosmology and cluster astrophysics. In this paper, we investigate the constraining power of the multiband cluster surveys, through a joint analysis of three observables associated with clusters of galaxies, including thermal Sunyaev–Zel’dovich (tSZ) effect in cosmic microwave background (CMB), X-ray emission of ionized gas, and gravitational weak lensing effect of background galaxies by the cluster’s gravitational potential. We develop a theoretical framework to predict and interpret two-point correlation statistics among the three observables using a semi-analytic model of intracluster medium (ICM) and halo-based approach. In this work, we show that the auto- and cross-angular power spectra in tSZ, X-ray, and lensing statistics from upcoming missions (eROSITA, CMB-S4, and LSST) can help break the degeneracy between cosmology and ICM physics. These correlation statistics are less sensitive to selection biases, and are able to probe ICM physics in distant, faint, and small clusters that are otherwise difficult to be detected individually. We show that the correlation statistics are able to provide cosmological constraints comparable to the conventional cluster abundance measurements, while constraining cluster astrophysics at the same time. Our results indicate that the correlation statistics can significantly enhance the scientific returns of upcoming multiwavelength cluster surveys.
Challenges and opportunities facing game theory and control: an interview with Tamer Başar
Authors: Zhang By Ji-Feng 
Published: October 2019

Abstract
The Control community has recently witnessed an almost exponentially growing interest in the application of game-theoretic concepts and tools in research on control, multi-agent systems, and networks. In an interview with NSR, Professor Tamer Başar, a member of the US National Academy of Engineering, Swanlund Endowed Chair and CAS Professor of Electrical and Computer Engineering, and Director of the Center for Advanced Study at the University of Illinois at Urbana-Champaign in the USA, former president of both the IEEE Control Systems Society and the American Automatic Control Council, and the founding president of the International Society of Dynamic Games, talked about the recently emerging role of game theory in control and networking research, how it broadens the territorial boundaries of control into disciplines outside engineering, and opportunities and challenges that lie ahead.
Are hyoliths Palaeozoic lophophorates?
Authors: Liu Fan , Skovsted Christian B , Topper Timothy P , Zhang Zhifei , Shu Degan 
Published: October 2019

Abstract
The phylogenetic position of hyoliths has long been unsettled, with recent discoveries of a tentaculate feeding apparatus (‘lophophore’) and fleshy apical extensions from the shell (‘pedicle’) suggesting a lophophorate affinity. Here, we describe the first soft parts associated with the feeding apparatus of an orthothecid hyolith, Triplicatella opimus from the Chengjiang biota of South China. The tuft-like arrangement of the tentacles of T. opimus differs from that of hyolithids, suggesting they collected food directly from the substrate. A reassessment of the feeding organ in hyolithids indicates that it does not represent a lophophore and our analysis of the apical structures associated with some orthothecids show that these represent crushed portions of the shell and are not comparable to the brachiopod pedicle. The new information suggests that hyoliths are more likely to be basal members of the lophotrochozoans rather than lophophorates closely linked with the Phylum Brachiopoda.
Optimal taxation with externalities of consumption and education spending
Authors: Zhang Jie 
Published: October 2019

Abstract
We investigate optimal taxation when a person’s utility decreases in others’ consumption and school quality increases in others’ education spending. Education externalities reduce education spending and schooling time from optimal levels, whereas consumption externalities cause high consumption relative to leisure and public goods. Internalizing education externalities supports education subsidies but opposite taxes on consumption and labour income. Internalizing consumption externalities supports consumption taxes but equal rates of labour income taxes and education subsidies. Internalizing both externalities justifies higher education subsidies than labour income taxes and positive taxes on labour income and consumption. We also investigate quantitative implications for tax reform and government debt sustainability.
Affective Rationalism and Religious Insight
Authors: Pittard John 
Published: October 2019

Abstract
This chapter considers further what implications rationalist weak conciliationism has for religious belief. Rationalist weak conciliationism may seem to imply that justified religious belief is a philosophical accomplishment reserved only for the analytically sophisticated and that personal religious experience plays at best a minor role in accounting for the rationality of religious belief. Resisting these alleged implications, the chapter argues against an “austere rationalism” that sees all rational insight as a product of dispassionate analytical faculties. A case is made for an “affective rationalism” that emphasizes the essential role played by the emotions in facilitating insights into evaluative questions, including evaluative questions that bear significantly on the plausibility of competing religious and irreligious outlooks. The chapter concludes with a discussion of examples that illustrate more concretely how rationalist weak conciliationism applies to situations of religious disagreement.
Missionary Calculus
Authors: Belvadi Anilkumar 
Published: October 2019

Abstract
Missionary Calculus tells the story for the first time of the making of the Sunday school in Victorian India (1858–1901), focusing on American missionaries, its most active promoters. Unlike other mission histories, this book studies the means missionaries adopted in building this institution rather than on their evangelical ends. Based on extensive archival research, it addresses the question: How did the process of building institutions affect the Christian values to establish which they were built? The book provides a richly detailed account of Indian colonial educational history, discussing the Christian pedagogical encounter with a non-Christian learning environment. It tells of lavish missionary lifestyles in a land frequently stricken by famine, and of missionary solidarity with British colonial authorities, accompanied though by Christian caritative commitment for the plight of the colonized. Missionaries resolved these contradictions by telling their audiences that becoming Christian would lead them to prosperity, while telling themselves that they needed to work out a plan for civilizational correction. Sunday schools began to be seen as at once the instrument of evangelization as of reschooling India. American missionaries brought with them Sunday school curricula and organizational methods from back home, and tried to customize them to Indian conditions. But this meant having to compromise with hiring heathen teachers, allowing heathen students to wear their caste-marks, commissioning a heathen-style hymnody, and paying money to key people to fill the classrooms with heathens. Could such a hybrid institution be Christian? And whom could it serve? Here is an East Indian tale.
Introduction
Authors: Belvadi Anilkumar 
Published: October 2019

Abstract
Chapter 1 introduces the central argument of the book, namely, that the means Christian missionaries adopted in building certain evangelical institutions in colonial India modified the ends they sought to achieve through building them. Observing that there are no studies on colonial Sunday schools, the chapter notes that the relevant missionary archives have fewer records of doctrinal debates between Christians and non-Christians than of missionary concerns over the means required for institution-building. Consequently, in keeping with the data, the chapter proposes employing a methodology that entails studying “means” over “ends.” To do this, it proposes adopting the theoretical framework of sociologist Max Weber, which draws a distinction between “substantive” and “instrumental” rationality. In the present study, this pair of concepts is taken to denote the distinction between missionaries’ beliefs and worldview or values or “ends,” and the material and symbolic resources or “means” they deployed in building Sunday schools. Further, applying the theory of institution-formation presented by sociologists Peter Berger and Thomas Luckmann, it proposes that Sunday schools were atypical institutions. Yet, such schools were built on compromise, with American Protestant missionaries taking the lead, and with different Indian social groups also taking an active part. The chapter foreshadows how the book presents the ends/means conflict among Sunday school builders throughout the Victorian colonial period (1858–1901), and how the compromises they reached signify universal values that transcended sectarian and national boundaries. The chapter situates the book among other approaches to colonial studies, and makes a case for its novelty.
The Creators of Sunday Schools
Authors: Belvadi Anilkumar 
Published: October 2019

Abstract
Chapter 3 situates American missionaries in the colonial Indian context. When they arrived in India (legally after 1833), annual missionary salaries, as early as in the 1840s, were in the range of $700 to $1,000, or thirty-five times average Indian earnings. They wrote of their large personal household establishments, which included spacious villas, retinues of several categories of servants, and transportation by way of palanquins or horses. Further, they socialized with British officers and their families. The chapter shows that missionaries were a part of the powerful ruling colonial elite, their caritative commitments and message of Christian humility notwithstanding. They reconciled these contradictions by offering their listeners the rationale that Christianity led to prosperity and a higher state of civilization. They observed the simultaneous existence of agricultural productivity and peasant poverty, and were unable to provide for themselves an explanation for the starkness of the contrast. As the evidence shows, missionaries attributed to the material depredations of the Indians their moral failures rather than the rapacious logic of colonial rule. This causal analysis provided missionaries with the justification for extending their evangelical message to a broader program of civilizational reform. Every element of their interaction with the poverty-stricken population around them began to be seen as an opportunity for moral and spiritual correction. Missionaries began to look upon themselves as builders and transformers of society rather than as mere carriers of a personal, religious message. The chapter ends with an American missionary’s reflections on finding systematic ways of educating Indians on the need for civilizational change.