bluuebunny/crossref_metadata_2025 huggingface dataset:
Vitamin D status in children and adults in Sweden: dietary intake and 25-hydroxyvitamin D concentrations in children aged 10–12 years and adults aged 18–80 years
Authors: Nälsén Cecilia , Becker Wulf , Pearson Monika , Ridefelt Peter , Lindroos Anna Karin , Kotova Natalia , Mattisson Irene
Published: October 2020

The study aimed to estimate vitamin D intake and plasma/serum 25-hydroxyvitamin D (25(OH)D) concentrations, investigate determinants of 25(OH)D concentrations and compare two 25(OH)D assays. We conducted two nationwide cross-sectional studies in Sweden with 206 school children aged 10–12 years and 1797 adults aged 18–80 years (n 268 provided blood samples). A web-based dietary record was used to assess dietary intake. Plasma/serum 25(OH)D was analysed by liquid chromatography-mass spectrometry (LC-MS) and immunoassay in adults and LC-MS/MS in children. Most participants reported a vitamin D intake below the average requirement (AR), 16 % of children and 33 % of adults met the AR (7⋅5 μg). In adults, plasma 25(OH)D below 30 and 50 nmol/l were found in 1 and 18 % of participants during the summer period and in 9 and 40 % of participants during the winter period, respectively. In children, serum 25(OH)D below 30 and 50 nmol/l were found in 5 and 42 % of participants (samples collected March–May), respectively. Higher 25(OH)D concentrations were associated with the summer season, vacations in sunny locations (adults), and dietary intake of vitamin D and use of vitamin D supplements, while lower concentrations were associated with a higher BMI and an origin outside of Europe. Concentrations of 25(OH)D were lower using the immunoassay than with the LC-MS assay, but associations with dietary factors and seasonal variability were similar. In conclusion, vitamin D intake was lower than the AR, especially in children. The 25(OH)D concentrations were low in many participants, but few participants had a concentration below 30 nmol/l.
Stochastic modeling of subglacial topography exposes uncertainty in water routing at Jakobshavn Glacier
Authors: MacKie Emma J. , Schroeder Dustin M. , Zuo Chen , Yin Zhen , Caers Jef
Published: October 2020

Subglacial topography is an important feature in numerous ice-sheet analyses and can drive the routing of water at the bed. Bed topography is primarily measured with ice-penetrating radar. Significant gaps, however, remain in data coverage that require interpolation. Topographic interpolations are typically made with kriging, as well as with mass conservation, where ice flow dynamics are used to constrain bed geometry. However, these techniques generate bed topography that is unrealistically smooth at small scales, which biases subglacial water flowpath models and makes it difficult to rigorously quantify uncertainty in subglacial drainage patterns. To address this challenge, we adapt a geostatistical simulation method with probabilistic modeling to stochastically simulate bed topography such that the interpolated topography retains the spatial statistics of the ice-penetrating radar data. We use this method to simulate subglacial topography using mass conservation topography as a secondary constraint. We apply a water routing model to each of these realizations. Our results show that many of the flowpaths significantly change with each topographic realization, demonstrating that geostatistical simulation can be useful for assessing confidence in subglacial flowpaths.
FRED M. DONNER, Narratives of lslamic Origins: The Beginnings of Islamic Historical Writing, Studies in Late Antiquity and Early Islam 14 (Princeton, N.J.: Darwin Press, 1998). Pp. 373.
Authors: MARTIN RICHARD C.
Published: October 2020

The origins and early development of Islam as determined from its most important and foundational texts is the project this book undertakes. As such, it stands in a tradition of Orientalist scholarship on early Muslim historiography that reaches back to the 19th century and that continues to generate debates among historians. Narratives of Islamic Origins is important for many reasons, not least because it clarifies the history of the issues that have divided historians, offering pointed critiques of major, particularly recent, works in the debate, while at the same time marking out a position that the author consistently defends in the Introduction and twelve chapters and appendixes. The use of the term “Orientalist” here is not meant to evoke, but rather to recognize—as Donner states at the outset—that European scholars of the 19th and early 20th centuries took Arabic sources seriously and made them available to succeeding generations. Donner's purpose is not to question their motives for doing this; rather, it is to analyze the textual evidence, arguments, and conclusions they adduced. The author has also written numerous articles and chapters on early Islamic history as well as the acclaimed and not uncontroversial book The Early Muslim Conquests (1981).
To see or not to see: The roles of item properties and language knowledge in Chinese missing logographeme effect
Authors: Tong Xiuli , Deng Qinli , Deacon Hélène , Saint-Aubin Jean , Wang Suiping
Published: October 2020

This study examined how language knowledge and item properties (i.e., semantic relatedness and position) influenced Chinese missing logographeme effects. Eighty-four Chinese readers and 53 English readers were asked to search for the Chinese logographeme 口 while reading a Chinese prose passage. The target 口 appeared in five different positions (i.e., left, right, top, bottom, or inside), varying its degree of semantic relatedness to its embedded characters. The generalized linear mixed-effect model revealed a significant interaction between semantic relatedness and position in Chinese, but not in English, readers when visual complexity and frequency were controlled. For Chinese readers, a higher omission rate occurred when 口 appeared in the top and inside positions and exhibited low semantic relatedness with its embedded characters, whereas 口 was omitted more when it was positioned on the right and exhibited high semantic relatedness to its embedded characters. English readers exhibited a different omission pattern: 口 was omitted more when it appeared in the left or right position irrespective of semantic relatedness. In addition, 口 was omitted more in the inside, rather than the bottom, position. These findings suggest that the omission rate of the logographeme is determined by item properties at the sublexical level and the reader’s language knowledge.
The Etymology of Despair in the Americas
Authors: Semán Ernesto
Published: October 2020

Halfway into White Noise, Don DeLillo's novel from 1985, Jack Gladney packs his family in the car and leaves town running from a black chemical cloud. The “airborne toxic event” had triggered an emergency evacuation plan: floodlights from helicopters, sirens, unmarked cars from obscure agencies, clogged roads, makeshift shelters at a Boy Scout camp where the Red Cross would dispense juice and coffee. People are confused, they seek information wherever they can, “[s]mall crowds collected around certain men.” Among generalized bewilderment, Gladney observes a few individuals moving faster and more assertively than the rest, then getting into a Land Rover. In the chaotic scene of crisis, their confidence gets his attention. “Their bumper stickers read GUN CONTROL IS MIND CONTROL” Gladney reads. And his mind wanders: “In situations like this, you want to stick close to people in right-wing fringe groups. They've practiced staying alive.”
LAPLACE BOUNDS APPROXIMATION FOR AMERICAN OPTIONS
Authors: Ma Jingtang , Cui Zhenyu , Li Wenyuan
Published: October 2020

In this paper, we develop the lower–upper-bound approximation in the space of Laplace transforms for pricing American options. We construct tight lower and upper bounds for the price of a finite-maturity American option when the underlying stock is modeled by a large class of stochastic processes, e.g. a time-homogeneous diffusion process and a jump diffusion process. The novelty of the method is to first take the Laplace transform of the price of the corresponding “capped (barrier) option” with respect to the time to maturity, and then carry out optimization procedures in the Laplace space. Finally, we numerically invert the Laplace transforms to obtain the lower bound of the price of the American option and further utilize the early exercise premium representation in the Laplace space to obtain the upper bound. Numerical examples are conducted to compare the method with a variety of existing methods in the literature as benchmark to demonstrate the accuracy and efficiency.
Acute aortic dissection in a patient with Williams syndrome infected by COVID-19
Authors: Mamishi Setareh , Navaeian Ameneh , Shabanian Reza
Published: October 2020

Cardiovascular involvement in COVID-19 has different features. Here we report the ominous fate of a neglected adolescent with Williams syndrome that was infected by SARS-CoV-2 and ended by acute aortic dissection.
Validity and reliability of the Iranian version of the Yale Food Addiction Scale for obese women
Authors: Panahi Moghaddam Seyedeh Atefeh , Amiri Parisa , Eini Zinab Hassan , Saidpour Atoosa
Published: October 2020

Objective:

The face and construct validity of the Iranian version of the Yale Food Addiction Scale (YFAS) was evaluated, and the convergent validity and test–retest reliability of both Iranian and original versions of YFAS for obese women were assessed.

Design:

The internal consistency of the YFAS was analysed. Exploratory factor analysis for dichotomous data was performed by varimax rotation, polychoric correlation coefficients and confirmatory factor analysis (CFA). Convergent validity was established by evaluating the correlation between the original and the Iranian versions of YFAS and the Binge Eating Scale (BES). The intraclass correlation coefficient (ICC) was measured between test–retest results.

Setting:

A weight management clinic in Tehran.

Participants:

450 obese women.

Results:

The single-factor structure indicated that the factor loadings for all the items were > 0·5, except for three items (explained proportion variance = 51 %). Based on CFA, the single factor had a better fit to the data after excluding three items. The Kuder–Richardson-20 coefficient was 0·86 for the total twenty-two items. The symptom count and diagnostic version of both the Iranian (ICC = 0·92 and 0·87, respectively) and original YFAS (ICC = 0·92 and 0·86, respectively) were stable over 2 weeks. Both the symptom count and the diagnostic version of these two scales had significant correlations with the measures of BES (P < 0·001).

Conclusions:

The initial reliability and validity of the Iranian version of the YFAS among obese women are supported. Further studies should be conducted on men and normal/overweight samples.
Radiation chemistry in astrochemical models: From the laboratory to the ISM
Authors: Shingledecker Christopher N. , Ivlev Alexei , Kästner Johannes , Herbst Eric , Caselli Paola
Published: October 2020

Most interstellar and planetary environments are suffused by a continuous flux of several types of ionizing radiation, including cosmic rays, stellar winds, x-rays, and gamma-rays from radionuclide decay. There is now a large body of experimental work showing that these kinds of radiation can trigger significant physicochemical changes in ices, including the dissociation of species (radiolysis), sputtering of surface species, and ice heating. Even so, modeling the chemical effects that result from interactions between ionizing radiation and interstellar dust grain ice mantles has proven challenging due to the complexity and variety of the underlying physical processes. To address this shortcoming, we have developed a method whereby such effects could easily be included in standard rate-equations-based astrochemical models. Here, we describe how such models, thus improved, can fruitfully be used to simulate experiments in order to better understand bulk chemistry at low temperatures.
Molecular line emission from planet-forming Herbig Ae disks
Authors: Booth Alice S. , Walsh Catherine
Published: October 2020

We present ALMA observations of four different molecular species in showcasing their potential as tracers of physical and chemical conditions in planet forming Herbig Ae disks.
Non-exploding and exploding core-collapse supernova models and the multimessenger predictions
Authors: Kotake Kei , Kuroda Takami , Takiwaki Tomoya
Published: October 2020

We present results of full general relativistic (GR), three-dimensional (3D) core-collapse simulation of a massive star with multi-energy neutrino transport. Using a 70Mȯ zero-metallicity star, we show that the black-hole (BH) formation occurs at ∼ 300 ms after bounce. At a few ∼ 10 ms before the BH formation, we find that the stalled bounce shock is revived by neutrino heating from the forming hot proto-neutron star (PNS), which is aided by vigorous convection behind the shock. Our numerical results present the first evidence to validate the BH formation by the so-called fallback scenario. Furthermore we present results from a rapidly rotating core-collapse model of a 27Mȯ star that is trending towards an explosion. We point out that the correlated neutrino and gravitational-wave signatures, if detected, could provide a smoking-gun evidence of rapid rotation of the newly-born PNS.
Infrared spectra of protonated and hydrogenated corannulene (C20H10) and sumanene (C21H12) using matrix isolation in solid para-hydrogen – implications for the UIR bands
Authors: Sundararajan Pavithraa , Tsuge Masashi , Baba Masaaki , Sakurai Hidehiro , Lee Yuan-Pern
Published: October 2020

Polycyclic aromatic hydrocarbons (PAH) and their derivatives, including protonated and cationic species, are suspected to be carriers of the unidentified infrared (UIR) emission bands observed from the galactic and extragalactic sources. We investigated the infrared (IR) spectra of protonated nonplanar PAHs: corannulene (C20H10) and sumanene (C21H12), that are regarded as a fragments of a fullerene,C60. The protonated corannulene H+ C20H10 and sumanene H+ C21H12 were produced in seperate experiments by bombarding a mixture of corannulene/sumanene and para-hydrogen (p-H2) with electrons during deposition at 3.2 K. During maintenance of the electron-bombarded matrix in darkness the intensities of IR lines of protonated corannulene decreased because of neutralization by electrons that were slowly released from the trapped sites whereas the hydrogenated species were produced. The observed lines were classified into several groups according to their responses to darkness and secondary irradiation at 365 nm/385 nm LEDs. Spectral assignments were derived based on a comparison of the observed spectra with those predicted with the B3PW91/6-311+ +G(2d,2p) method. The observed IR spectrum of hub-H+ C20H10, the most stable protonated isomer, resembles several bands of the Class-A UIR bands.
Density diagnostics of photoionized outflows in active galactic nuclei
Authors: Mao Junjie
Published: October 2020

Photoionized outflows in active galactic nuclei (AGNs) are thought to influence their circumnuclear and host galactic environment. However, the distance of the outflow with respect to the black hole is poorly constrained, which limits our understanding of the kinetic power by the outflow. Therefore, the impact of AGN outflows on their host galaxies is uncertain. If the density of the outflow is known, its distance can be derived. Density measurement via variability studies and density sensitive lines have been used, albeit not very effective in the X-ray band. Good measurements are rather demanding or challenging for the current generation of (grating) spectrometers. The next generation of spectrometers will certainly provide data with better quality and large quantity, leading to tight constraints on the location and the kinetic power of AGN outflows. This contribution summarizes the state-of-the-art in this field.
Bridging the gap between laboratory astrophysics and quantum chemistry: The concept of potential energy surfaces
Authors: Rocha C. M. R.
Published: October 2020

An exotic molecular inventory exists in space. While some species have well-known terrestrial analogs, others are very reactive and can hardly survive in the laboratory timely to allow for their characterization. With an eye toward these latter, we highlight in this contribution the role of quantum chemistry in providing astrochemically relevant data where experiment struggles. Special attention is given to the concept of molecular potential energy surfaces (PESs), a key aspect in theoretical chemical physics, and the possible dynamical attributes taken therefrom. As case studies, we outline our current efforts in obtaining global PESs of carbon clusters. It is thus hoped that, with such an active synergy between theoretical chemistry and state-of-the-art experimental/observational techniques (the pillars to the modern laboratory astrophysics), scientists may gather the required knowledge to explain the origins, abundances and the driving force toward molecular complexity in the Universe.
Measured mass to stoichoimetric formula through exhaustive search
Authors: Orthous-Daunay François-Régis , Thissen Roland , Vuitton Véronique
Published: October 2020

Electrospray ionisation has revolutionised mass spectrometry. Coupled to high mass resolution, it provides the stoichiometric formula of a lot of molecules in a mixture. The link between the mass spectrometry data and the chemical description relies on an interpretation of the measured masses. We present here the tools and tricks developed to exploit Orbitrap mass spectra. This piece of work focuses on the numerical method to assign a molecular formula to a measured mass. The problem is restrained to the solving of the Diophantine equation where the constant coefficients are stoichiometric groups. Peculiar case of a set of convenient groups is given with the chemical constraints it brings to the problem.
Effects of satellite lines in fittings of He-like triplets of X-ray Spectra
Authors: Zhang Lan , Xue Xiangxiang , Yuan Dawei , Wei Huigang , Wang Feilu , Zhao Gang
Published: October 2020

We estimate the wind speeds with a Bayesian inference and a Markov Chain Monte Carlo (MCMC) tool for the high resolution X-ray spectra of Vela X-1, to understand the effect of satellite lines on spectral analysis. After modelling continua and He-like triplets of the spectra with a parameterized two-component power-law model and a mullti-Gaussian model, respectively, we estimate the contamination from satellite lines, and improve the self-consistency of wind speeds derived from the He-like triplet lines of different elements. Moreover, our fitting shows that the column density of scatter component varies from phase to phase.
Questions about the evolution of ices, from diffuse molecular clouds to comets
Authors: Boogert A. C. A.
Published: October 2020

The surfaces of interstellar and circumstellar dust grains are the sites of molecule formation, most of which, except H2, stick and form ice mantles. The study of ice evolution thus seems directly relevant for understanding our own origins, although the relation between interstellar and solar system ices remains a key question. The comparison of interstellar and solar system ices relies evidently on an accurate understanding of the composition and processes in both environments. With the accurate in situ measurements available for the comet 67P/Churyumov-Gerasimenko with the Rosetta mission, improving our understanding of interstellar ices is the more important. Here, I will address three specific questions. First, while laboratory experiments have made much progress in understanding complex organic molecule (COM) formation in the ices, the question remains, how does COM formation depend on environment and time? Second, what is the carrier of sulfur in the ices? And third, can ice absorption bands trace the processing history of the ices? Laboratory experiments, ranging from infrared spectroscopy to identify interstellar ice species, to surface experiments to determine reaction parameters in ice formation scenarios, to heating and irradiation experiments to simulate space environments, are essential to address these questions and analyze the flood of new observational data that will become available with new facilities in the next 2-10 years.
Kuiper Belt object 2014MU69, Pluto and Phoebe as windows on the composition of the early solar nebula
Authors: Pendleton Y. J. , Cruikshank D. P. , Stern S. A. , Dalle Ore C. M. , Grundy W. , Materese C. , Protopapa S. , Schmitt B. , Lisse C.
Published: October 2020

The initial chemical composition of a proto-planetary nebula depends upon the degree to which 1) organic and ice components form on dust grains, 2) organic and molecular species form in the gas phase, 3) organics and ices are exchanged between the gas and solid state, and 4) the precursor and newly formed (more complex) materials survive and are modified in the developing planetary system. Infrared and radio observations of star-forming regions reveal that complex chemistry occurs on icy grains, often before stars even form. Additional processing, through the proto-planetary disk (PPD) further modifies most, but not all, of the initial materials. In fact, the modern Solar System still carries a fraction of its interstellar inheritance (Alexander et al.2017). Here we focus on three examples of small bodies in our Solar System, each containing chemical and dynamical clues to its origin and evolution: the small-cold classical Kuiper Belt object (KBO) 2014 MU69, Pluto, and Saturn’s moon, Phoebe. The New Horizons flyby of 2014 MU69 has given the first view of an unaltered body composed of material originally in the solar nebula at ~45 AU. The spectrum of MU69 reveals methanol ice (not commonly found), a possible detection of water ice, and the noteworthy absence of methane ice (Stern et al. 2019). Pluto’s internal and surface inventory of volatiles and complex organics, together with active geological processes including cryo-volcanism, indicate a surprising level of activity on a body in the outermost region of the Solar System, and the fluid that emerges from subsurface reservoirs may contain material inherited from the solar nebula (Cruikshank et al.2019a,b). Meanwhile, Saturn’s captured moon, Phoebe, carries high D/H in H2O (Clark et al. 2019) and complex organics (Cruikshank et al. 2008), both consistent with its formation in, and inheritance from, the outer region of the solar nebula. Together, these objects provide windows on the origin and evolution of our Solar System and constraints to be considered in future chemical and physical models of PPDs.
Asteroid collisions as origin of debris disks: Asteroid shape reconstruction from BNAO Rozhen photometry
Authors: Apostolovska G. , Vchkova Bebekovska E. , Kostov A. , Donchev Z.
Published: October 2020

As a result of collisions during their lifetimes, asteroids have a large variety of different shapes. It is believed that high velocity collisions or rotational spin-up of asteroids continuously replenish the Sun’s zodiacal cloud and debris disks around extrasolar planets (Jewitt (2010)). Knowledge of the spin and shape parameters of the asteroids is very important for understanding collision asteroid processes. Lately photometric observations of asteroids showed that variations in brightness are not accompanied by variations in colour index which indicate that the shape of the lightcurve is caused by varying illuminations of the asteroid surface rather than albedo variations over the surface. This conclusion became possible when photometric investigations were combined with laboratory experiments (Dunlap (1971)). In this article using the convex lightcurve inversion method we obtained the sense of rotation, pole solutions and preliminary shape of 901 Brunsia.
Natural transportation routes in the Solar System
Authors: Todorović Nataša
Published: October 2020

The aim of this work is to explain the possible mechanism in the early Solar System, by which water-rich asteroids may have been delivered to Earth. Carbonaceous (C-type) asteroids, with a large fraction of water molecules, dominate in the outer part of the asteroid belt and the possibility of their migration toward Earth is still not well explained. In this work, we observe very efficient dynamical routes along which C-type water-bearing asteroids are delivered to Earth.
H-atom irradiation of solid state formamide at 12 K
Authors: Suhasaria Tushar , Mennella Vito
Published: October 2020

The aim of this work is to understand the stability and investigate the chemical evolution of formamide ice due to thermal hydrogenation at simulated interstellar conditions.
Synthesis of solid-state complex organic molecules through accretion of simple species at low temperatures
Authors: Qasim D. , Fedoseev G. , Chuang K.-J. , Taquet V. , Lamberts T. , He J. , Ioppolo S. , van Dishoeck E. F. , Linnartz H.
Published: October 2020

Complex organic molecules (COMs) have been detected in the gas-phase in cold and lightless molecular cores. Recent solid-state laboratory experiments have provided strong evidence that COMs can be formed on icy grains through ‘non-energetic’ processes. In this contribution, we show that propanal and 1-propanol can be formed in this way at the low temperature of 10 K. Propanal has already been detected in space. 1-propanol is an astrobiologically relevant molecule, as it is a primary alcohol, and has not been astronomically detected. Propanal is the major product formed in the C2H2 + CO + H experiment, and 1-propanol is detected in the subsequent propanal + H experiment. ALMA observations towards IRAS 16293-2422B are discussed and provide a 1-propanol:propanal upper limit of < 0.35–0.55, which are complemented by computationally-derived activation barriers in addition to the performed laboratory experiments.
Observations of the photochemical evolution of carbonaceous macromolecules in star-forming regions
Authors: Berné Olivier
Published: October 2020

The goal of this contribution is to illustrate how spatially resolved spectroscopic observations of the infrared emission of UV irradiated regions, from star forming regions to the diffuse ISM, can be used to rationalize the chemical evolution of carbonaceous macromolecules in space, with the help of astrophysical models. For instance, observations with the Spitzer space telescope lead to the idea that fullerenes (including C60 can form top-down from Polycyclic Aromatic Hydrocarbons in the interstellar medium. The possibility that this process can occur in space was tested using a photochemical model which includes the key molecular parameters derived from experimental and theoretical studies. This approach allows to test the likelihood that the proposed path is realistic, but, more importantly, it allows to isolate the key physical processes and parameters that are required to capture correctly the evolution of carbonaceous molecules in space. In this specific case, we found that relaxation through thermally excited electronic states (a physical mechanism that is largely unexplored, except by few a teams) is one of the keys to model the photochemistry of the considered species. Subsequent quantum chemical studies stimulated by the (limited) astrophysical model showed that a detailed mapping of the energetics of isomerization and de-hydrogenation is necessary to understand the competition between these processes in space.

Such approaches, involving experimentalists and theoreticians, are particularly promising in the context of the upcoming JWST mission, which will provide access to the signatures of carbonaceous species in emission and in absorption at an angular resolution that will enable to reach new chemical frontiers in star and even in planet forming regions.
The Wootton center for astrophysical plasma properties: First results for helium
Authors: Montgomery M. H. , Winget D. E. , Schaeuble M.-A. , Dunlap B. H. , Fuchs J. T.
Published: October 2020

The Wootton Center for Astrophysical Plasma Properties (WCAPP) is a new center focusing on the spectroscopic properties of stars and accretion disks using “at-parameter” experiments. Currently, these experiments use the X-ray output of the Z machine at Sandia National Laboratories — the largest X-ray source in the world — to heat plasmas to the same conditions (temperature, density, and radiation environment) as those observed in astronomical objects. The experiments include measuring (1) density-dependent opacities of iron-peak elements at solar interior conditions, (2) spectral lines of low-Z elements at white dwarf photospheric conditions, (3) atomic population kinetics of neon in a radiation-dominated environment, and (4) resonant Auger destruction (RAD) of silicon at conditions found in accretion disks around supermassive black holes. In particular, we report on recent results of our experiments involving helium at white dwarf photospheric conditions. We present results showing disagreement between inferred electron densities using the Hβ line and the He I 5876 Å line, most likely indicating incompleteness in our modeling of this helium line.
Recent advances in experimental laboratory astrophysics for stellar astrophysics applications and future data needs
Authors: Pickering Juliet C. , Teresa Belmonte Maria , Clear Christian P. , Liggins Florence , Concepcion-Mairey Florence
Published: October 2020

Accurate atomic data for line wavelengths, energy levels, line broadening such as hyperfine structure and isotope structure, and f-values, particularly for the line rich iron group elements, are needed for stellar astrophysics applications, and examples of recent measurements are given. These atomic data are essential for determination of elemental abundances in astronomical objects. With modern facilities, telescopes and spectrographs, access to underexplored regions (IR, UV, VUV), and improved stellar atmosphere models (3D, NLTE), and extremely large datasets, astronomers are tackling problems ranging from studying Galactic chemical evolution, to low mass stars and exoplanets. Such advances require improved accuracy and completeness of the atomic database for analyses of astrophysical spectra.
Simulations of energy dissipation and non-thermal desorption on amorphous solid water
Authors: Cuppen H. M. , Fredon A.
Published: October 2020

Dust particles covered by icy mantles play a crucial role in the formation of molecules in the Interstellar Medium (ISM). These icy mantles are mainly composed of water but many other chemical species are also contained in these ices. These compounds can diffuse and meet each other to react. It is through these surface reactions that new saturated species are formed. Photodissociation reactions are also thought to play a crucial role in the formation of radical species. Complex organic molecules are formed through an intricated network of photodissociation and surface reactions.

Both type of reactions release energy. Surface reactions are typically exothermic by a few eV, whereas photodissociation reactions are triggered by the absorption of a UV photon, resulting in the formation of highly excited products. The excited reaction products can apply this energy for desorption or diffusion, making products more mobile than predicted when considering only thermal hopping. The energy could further lead to annealing or deformation of the ice structure.

Here we would like to quantify the relative importance of these different energy dissipation routes. For this we performed thousands of Molecular Dynamics simulations for three different species (CO2, H2O and CH4) on top of a water ice surface. We consider different types of excitation such as translational, rotational, and/or vibrational excitation. The applied substrate is an amorphous solid water surface (ASW).
TERMINAL FLOWER 1-FD complex target genes and competition with FLOWERING LOCUS T
Authors: Zhu Yang , Klasfeld Samantha , Jeong Cheol Woong , Jin Run , Goto Koji , Yamaguchi Nobutoshi , Wagner Doris
Published: October 2020

Plants monitor seasonal cues to optimize reproductive success by tuning onset of reproduction and inflorescence architecture. TERMINAL FLOWER 1 (TFL1) and FLOWERING LOCUS T (FT) and their orthologs antagonistically regulate these life history traits, yet their mechanism of action, antagonism and targets remain poorly understood. Here, we show that TFL1 is recruited to thousands of loci by the bZIP transcription factor FD. We identify the master regulator of floral fate, LEAFY (LFY) as a target under dual opposite regulation by TFL1 and FT and uncover a pivotal role of FT in promoting flower fate via LFY upregulation. We provide evidence that the antagonism between FT and TFL1 relies on competition for chromatin-bound FD at shared target loci. Direct TFL1-FD regulated target genes identify this complex as a hub for repressing both master regulators of reproductive development and endogenous signalling pathways. Our data provide mechanistic insight into how TFL1-FD sculpt inflorescence architecture, a trait important for reproductive success, plant architecture and yield.
Large-scale genome sequencing of mycorrhizal fungi provides insights into the early evolution of symbiotic traits
Authors: Miyauchi Shingo , Kiss Enikő , Kuo Alan , Drula Elodie , Kohler Annegret , Sánchez-García Marisol , Morin Emmanuelle , Andreopoulos Bill , Barry Kerrie W. , Bonito Gregory , Buée Marc , Carver Akiko , Chen Cindy , Cichocki Nicolas , Clum Alicia , Culley David , Crous Pedro W. , Fauchery Laure , Girlanda Mariangela , Hayes Richard D. , Kéri Zsófia , LaButti Kurt , Lipzen Anna , Lombard Vincent , Magnuson Jon , Maillard François , Murat Claude , Nolan Matt , Ohm Robin A. , Pangilinan Jasmyn , Pereira Maíra de Freitas , Perotto Silvia , Peter Martina , Pfister Stephanie , Riley Robert , Sitrit Yaron , Stielow J. Benjamin , Szöllősi Gergely , Žifčáková Lucia , Štursová Martina , Spatafora Joseph W. , Tedersoo Leho , Vaario Lu-Min , Yamada Akiyoshi , Yan Mi , Wang Pengfei , Xu Jianping , Bruns Tom , Baldrian Petr , Vilgalys Rytas , Dunand Christophe , Henrissat Bernard , Grigoriev Igor V. , Hibbett David , Nagy László G. , Martin Francis M.
Published: October 2020

Mycorrhizal fungi are mutualists that play crucial roles in nutrient acquisition in terrestrial ecosystems. Mycorrhizal symbioses arose repeatedly across multiple lineages of Mucoromycotina, Ascomycota, and Basidiomycota. Considerable variation exists in the capacity of mycorrhizal fungi to acquire carbon from soil organic matter. Here, we present a combined analysis of 135 fungal genomes from 73 saprotrophic, endophytic and pathogenic species, and 62 mycorrhizal species, including 29 new mycorrhizal genomes. This study samples ecologically dominant fungal guilds for which there were previously no symbiotic genomes available, including ectomycorrhizal Russulales, Thelephorales and Cantharellales. Our analyses show that transitions from saprotrophy to symbiosis involve (1) widespread losses of degrading enzymes acting on lignin and cellulose, (2) co-option of genes present in saprotrophic ancestors to fulfill new symbiotic functions, (3) diversification of novel, lineage-specific symbiosis-induced genes, (4) proliferation of transposable elements and (5) divergent genetic innovations underlying the convergent origins of the ectomycorrhizal guild.
Stabilizing a metalloid {Zn12} unit within a polymetallide environment in [K2Zn20Bi16]6−
Authors: Eulenstein Armin R. , Franzke Yannick J. , Bügel Patrick , Massa Werner , Weigend Florian , Dehnen Stefanie
Published: October 2020

The access to molecules comprising direct Zn–Zn bonds has become very topical in recent years for various reasons. Low-valent organozinc compounds show remarkable reactivities, and larger Zn–Zn-bonded gas-phase species exhibit a very unusual coexistence of insulating and metallic properties. However, as Zn atoms do not show a high tendency to form clusters in condensed phases, synthetic approaches for generating purely inorganic metalloid Znx units under ambient conditions have been lacking so far. Here we show that the reaction of a highly reductive solid with the nominal composition K5Ga2Bi4 with ZnPh2 at room temperature yields the heterometallic cluster anion [K2Zn20Bi16]6–. A 24-atom polymetallide ring embeds a metalloid {Zn12} unit. Density functional theory calculations reveal multicenter bonding, an essentially zero-valent situation in the cluster center, and weak aromaticity. The heterometallic character, the notable electron-delocalization, and the uncommon nano-architecture points at a high potential for nano-heterocatalysis.
Jagged1-Notch1-deployed tumor perivascular niche promotes breast cancer stem cell phenotype through Zeb1
Authors: Jiang Huimin , Zhou Chen , Zhang Zhen , Wang Qiong , Wei Huimin , Shi Wen , Li Jianjun , Wang Zhaoyang , Ou Yang , Wang Wenhao , Wang Hang , Zhang Quansheng , Sun Wei , Sun Peiqing , Yang Shuang
Published: October 2020

Zinc finger E-box binding homeobox 1 (Zeb1) has been demonstrated to participate in the acquisition of the properties of cancer stem cells (CSCs). However, it is largely unknown how signals from the tumor microenvironment (TME) contribute to aberrant Zeb1 expression. Here, we show that Zeb1 depletion suppresses stemness, colonization and the phenotypic plasticity of breast cancer. Moreover, we demonstrate that, with direct cell-cell contact, TME-derived endothelial cells provide the Notch ligand Jagged1 (Jag1) to neighboring breast CSCs, leading to Notch1-dependent upregulation of Zeb1. In turn, ectopic Zeb1 in tumor cells increases VEGFA production and reciprocally induces endothelial Jag1 in a paracrine manner. Depletion of Zeb1 disrupts this positive feedback loop in the tumor perivascular niche, which eventually lessens tumor initiation and progression in vivo and in vitro. In this work, we highlight that targeting the angiocrine Jag1-Notch1-Zeb1-VEGFA loop decreases breast cancer aggressiveness and thus enhances the efficacy of antiangiogenic therapy.
High-throughput mutagenesis reveals unique structural features of human ADAR1
Authors: Park SeHee , Doherty Erin E. , Xie Yixuan , Padyana Anil K. , Fang Fang , Zhang Yue , Karki Agya , Lebrilla Carlito B. , Siegel Justin B. , Beal Peter A.
Published: October 2020

Adenosine Deaminases that act on RNA (ADARs) are enzymes that catalyze adenosine to inosine conversion in dsRNA, a common form of RNA editing. Mutations in the human ADAR1 gene are known to cause disease and recent studies have identified ADAR1 as a potential therapeutic target for a subset of cancers. However, efforts to define the mechanistic effects for disease associated ADAR1 mutations and the rational design of ADAR1 inhibitors are limited by a lack of structural information. Here, we describe the combination of high throughput mutagenesis screening studies, biochemical characterization and Rosetta-based structure modeling to identify unique features of ADAR1. Importantly, these studies reveal a previously unknown zinc-binding site on the surface of the ADAR1 deaminase domain which is important for ADAR1 editing activity. Furthermore, we present structural models that explain known properties of this enzyme and make predictions about the role of specific residues in a surface loop unique to ADAR1.
COMPOSITUM 1 contributes to the architectural simplification of barley inflorescence via meristem identity signals
Authors: Poursarebani Naser , Trautewig Corinna , Melzer Michael , Nussbaumer Thomas , Lundqvist Udda , Rutten Twan , Schmutzer Thomas , Brandt Ronny , Himmelbach Axel , Altschmied Lothar , Koppolu Ravi , Youssef Helmy M. , Sibout Richard , Dalmais Marion , Bendahmane Abdelhafid , Stein Nils , Xin Zhanguo , Schnurbusch Thorsten
Published: October 2020

Grasses have varying inflorescence shapes; however, little is known about the genetic mechanisms specifying such shapes among tribes. Here, we identify the grass-specific TCP transcription factor COMPOSITUM 1 (COM1) expressing in inflorescence meristematic boundaries of different grasses. COM1 specifies branch-inhibition in barley (Triticeae) versus branch-formation in non-Triticeae grasses. Analyses of cell size, cell walls and transcripts reveal barley COM1 regulates cell growth, thereby affecting cell wall properties and signaling specifically in meristematic boundaries to establish identity of adjacent meristems. COM1 acts upstream of the boundary gene Liguleless1 and confers meristem identity partially independent of the COM2 pathway. Furthermore, COM1 is subject to purifying natural selection, thereby contributing to specification of the spike inflorescence shape. This meristem identity pathway has conceptual implications for both inflorescence evolution and molecular breeding in Triticeae.
Reptile-like physiology in Early Jurassic stem-mammals
Authors: Newham Elis , Gill Pamela G. , Brewer Philippa , Benton Michael J. , Fernandez Vincent , Gostling Neil J. , Haberthür David , Jernvall Jukka , Kankaanpää Tuomas , Kallonen Aki , Navarro Charles , Pacureanu Alexandra , Richards Kelly , Brown Kate Robson , Schneider Philipp , Suhonen Heikki , Tafforeau Paul , Williams Katherine A. , Zeller-Plumhoff Berit , Corfe Ian J.
Published: October 2020

Despite considerable advances in knowledge of the anatomy, ecology and evolution of early mammals, far less is known about their physiology. Evidence is contradictory concerning the timing and fossil groups in which mammalian endothermy arose. To determine the state of metabolic evolution in two of the earliest stem-mammals, the Early JurassicMorganucodonandKuehneotherium, we use separate proxies for basal and maximum metabolic rate. Here we report, using synchrotron X-ray tomographic imaging of incremental tooth cementum, that they had maximum lifespans considerably longer than comparably sized living mammals, but similar to those of reptiles, and so they likely had reptilian-level basal metabolic rates. Measurements of femoral nutrient foramina showMorganucodonhad blood flow rates intermediate between living mammals and reptiles, suggesting maximum metabolic rates increased evolutionarily before basal metabolic rates. Stem mammals lacked the elevated endothermic metabolism of living mammals, highlighting the mosaic nature of mammalian physiological evolution.
AKT-induced lncRNA VAL promotes EMT-independent metastasis through diminishing Trim16-dependent Vimentin degradation
Authors: Tian Han , Lian Rong , Li Yun , Liu Chenying , Liang Shujun , Li Wei , Tao Tianyu , Wu Xingui , Ye Yaokai , Yang Xia , Han Jian , Chen Xuwei , Li Jun , He Yukai , Li Mengfeng , Wu Jueheng , Cai Junchao
Published: October 2020

Despite the importance of AKT overactivation in tumor progression, results from clinical trials of various AKT inhibitors remain suboptimal, suggesting that AKT-driven tumor metastasis needs to be further understood. Herein, based on long non-coding RNA (lncRNA) profiling induced by active AKT, we identify that VAL (Vimentin associated lncRNA, LINC01546), which is directly induced by AKT/STAT3 signaling, functions as a potent pro-metastatic molecule and is essential for active AKT-induced tumor invasion, metastasis and anoikis resistance in lung adenocarcinoma (LAD). Impressively, chemosynthetic siRNAs against VAL shows great therapeutic potential in AKT overactivation-driven metastasis. Interestingly, similar to activated AKT in LAD cells, although unable to induce epithelial-mesenchymal transition (EMT), VAL exerts potent pro-invasive and pro-metastatic effects through directly binding to Vimentin and competitively abrogating Trim16-depedent Vimentin polyubiquitination and degradation. Taken together, our study provides an interesting demonstration of a lncRNA-mediated mechanism for active AKT-driven EMT-independent LAD metastasis and indicates the great potential of targeting VAL or Vimentin stability as a therapeutic approach.
Analysis of SARS-CoV-2 vertical transmission during pregnancy
Authors: Fenizia Claudio , Biasin Mara , Cetin Irene , Vergani Patrizia , Mileto Davide , Spinillo Arsenio , Gismondo Maria Rita , Perotti Francesca , Callegari Clelia , Mancon Alessandro , Cammarata Selene , Beretta Ilaria , Nebuloni Manuela , Trabattoni Daria , Clerici Mario , Savasi Valeria
Published: October 2020

The impact of SARS-CoV-2 infection during gestation remains unclear. Here, we analyse the viral genome on maternal and newborns nasopharyngeal swabs, vaginal swabs, maternal and umbilical cord plasma, placenta and umbilical cord biopsies, amniotic fluids and milk from 31 mothers with SARS-CoV-2 infection. In addition, we also test specific anti-SARS-CoV-2 antibodies and expression of genes involved in inflammatory responses in placentas, and in maternal and umbilical cord plasma. We detect SARS-CoV-2 genome in one umbilical cord blood and in two at-term placentas, in one vaginal mucosa and in one milk specimen. Furthermore, we report the presence of specific anti-SARS-CoV-2 IgM and IgG antibodies in one umbilical cord blood and in one milk specimen. Finally, in the three documented cases of vertical transmission, SARS-CoV-2 infection was accompanied by a strong inflammatory response. Together, these data support the hypothesis that in utero SARS-CoV-2 vertical transmission, while low, is possible. These results might help defining proper obstetric management of COVID-19 pregnant women, or putative indications for mode and timing of delivery.
Multi-functional flexible 2D carbon nanostructured networks
Authors: Zhang Shichao , Liu Hui , Yu Jianyong , Li Bingyun , Ding Bin
Published: October 2020

Two-dimensional network-structured carbon nanoscale building blocks, going beyond graphene, are of fundamental importance, and creating such structures and developing their applications have broad implications in environment, electronics and energy. Here, we report a facile route, based on electro-spraying/netting, to self-assemble two-dimensional carbon nanostructured networks on a large scale. Manipulation of the dynamic ejection, deformation and assembly of charged droplets by control of Taylor cone instability and micro-electric field, enables the creation of networks with characteristics combining nanoscale diameters of one-dimensional carbon nanotube and lateral infinity of two-dimensional graphene. The macro-sized (meter-level) carbon nanostructured networks show extraordinary nanostructural properties, remarkable flexibility (soft polymeric mechanics having hard inorganic matrix), nanoscale-level conductivity, and outstanding performances in distinctly different areas like filters, separators, absorbents, and wearable electrodes, supercapacitors and cells. This work should make possible the innovative design of high-performance, multi-functional carbon nanomaterials for various applications.
Andean drought and glacial retreat tied to Greenland warming during the last glacial period
Authors: Woods Arielle , Rodbell Donald T. , Abbott Mark B. , Hatfield Robert G. , Chen Christine Y. , Lehmann Sophie B. , McGee David , Weidhaas Nicholas C. , Tapia Pedro M. , Valero-Garcés Blas L. , Bush Mark B. , Stoner Joseph S.
Published: October 2020

Abrupt warming events recorded in Greenland ice cores known as Dansgaard-Oeschger (DO) interstadials are linked to changes in tropical circulation during the last glacial cycle. Corresponding variations in South American summer monsoon (SASM) strength are documented, most commonly, in isotopic records from speleothems, but less is known about how these changes affected precipitation and Andean glacier mass balance. Here we present a sediment record spanning the last ~50 ka from Lake Junín (Peru) in the tropical Andes that has sufficient chronologic precision to document abrupt climatic events on a centennial-millennial time scale. DO events involved the near-complete disappearance of glaciers below 4700 masl in the eastern Andean cordillera and major reductions in the level of Peru’s second largest lake. Our results reveal the magnitude of the hydroclimatic disruptions in the highest reaches of the Amazon Basin that were caused by a weakening of the SASM during abrupt arctic warming. Accentuated warming in the Arctic could lead to significant reductions in the precipitation-evaporation balance of the southern tropical Andes with deleterious effects on this densely populated region of South America.