bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Closer Look at Exoplanet Occurrence Rates: Considering the Multiplicity of Stars without Detected Planets
Authors: Savel Arjun B. , Dressing Courtney D. , Hirsch Lea A. , Ciardi David R. , Fleming Jordan P. C. , Giacalone Steven A. , Mayo Andrew W. , Christiansen Jessie L. 
Published: November 2020

Abstract
One core goal of the Kepler mission was to determine the frequency of Earth-like planets that orbit Sun-like stars. Accurately estimating this planet occurrence rate requires both a well-vetted list of planets and a clear understanding of the stars searched for planets. Previous ground-based follow-up observations have, through a variety of methods, sought to improve our knowledge of stars that are known to host planets. Kepler targets without detected planets, however, have not been subjected to the same intensity of follow-up observations. In this paper, we constrain better the stellar multiplicity for stars around which Kepler could have theoretically detected a transiting Earth-sized planet in the habitable zone. We subsequently aim to improve estimates of the exoplanet search completeness—the fraction of exoplanets that were detected by Kepler—with our analysis. By obtaining adaptive optics observations of 71 Kepler target stars from the Shane 3 m telescope at Lick Observatory, we detected 14 candidate stellar companions within 4″ of 13 target stars. Of these 14 candidate stellar companions, we determine through multiple independent methods that 3 are likely to be bound to their corresponding target star. We then assess the impact of our observations on exoplanet occurrence rate calculations, finding an increase in occurrence of 6% (0.9σ) for various estimates of the frequency of Earth-like planets and an increase of 26% (4.5σ) for super-Earths and sub-Neptunes. These occurrence increases are not entirely commensurate with theoretical predictions, though this discrepancy may be due to differences in the treatment of stellar binarity.
Beyond Equilibrium Temperature: How the Atmosphere/Interior Connection Affects the Onset of Methane, Ammonia, and Clouds in Warm Transiting Giant Planets
Authors: Fortney Jonathan J. , Visscher Channon , Marley Mark S. , Hood Callie E. , Line Michael R. , Thorngren Daniel P. , Freedman Richard S. , Lupu Roxana 
Published: November 2020

Abstract
The atmospheric pressure–temperature profiles for transiting giant planets cross a range of chemical transitions. Here we show that the particular shapes of these irradiated profiles for warm giant planets below ∼1300 K lead to striking differences in the behavior of nonequilibrium chemistry compared to brown dwarfs of similar temperatures. Our particular focus is H2O, CO, CH4, CO2, and NH3 in Jupiter- and Neptune-class planets. We show that the cooling history of a planet, which depends most significantly on planetary mass and age, can have a dominant effect on abundances in the visible atmosphere, often swamping trends one might expect based on T
eq alone. The onset of detectable CH4 in spectra can be delayed to lower T
eq for some planets compared to equilibrium, or pushed to higher T
eq. The detectability of NH3 is typically enhanced compared to equilibrium expectations, which is opposite to the brown dwarf case. We find that both CH4 and NH3 can become detectable at around the same T
eq (at T
eq values that vary with mass and metallicity), whereas these “onset” temperatures are widely spaced for brown dwarfs. We suggest observational strategies to search for atmospheric trends and stress that nonequilibrium chemistry and clouds can serve as probes of atmospheric physics. As examples of atmospheric complexity, we assess three Neptune-class planets, GJ 436b, GJ 3470b, and WASP-107, all around T
eq = 700 K. Tidal heating due to eccentricity damping in all three planets heats the deep atmosphere by thousands of degrees and may explain the absence of CH4 in these cool atmospheres. Atmospheric abundances must be interpreted in the context of physical characteristics of the planet.
Biases and Cosmic Variance in Molecular Gas Abundance Measurements at High Redshift
Authors: Keenan Ryan P. , Marrone Daniel P. , Keating Garrett K. 
Published: November 2020

Abstract
Recent deep millimeter-wave surveys have attempted to measure the carbon monoxide (CO) luminosity function and mean molecular gas density through blind detections of CO emission lines. While the cosmic star formation rate density is now constrained in fields of hundreds of square arcminutes or more, molecular gas studies have been limited to ≤50 arcmin2. These small fields result in significant biases that have not been accounted for in published results. To quantify these biases, we assign CO luminosities to halos in cosmological simulations to produce mock observations for a range of field sizes. We find that fields of ≲10 arcmin2 alter the recovered shape of the luminosity function, causing underestimates of the number of bright objects. Our models suggest that current surveys are sensitive enough to detect sources responsible for approximately half of the cosmic molecular gas density at high redshift. However, uncertainties in the gas density measurement are large, and cosmic variance may double the uncertainty claimed in these surveys. As a result, the field size needed to detect redshift evolution in the molecular gas at high confidence may be more than one order of magnitude larger than what current surveys have achieved. Shot power intensity mapping measurements are particularly sensitive to Poisson variance and require yet larger areas to constrain the gas density or its evolution. We provide a simple prescription for approximating uncertainty in total CO emission as a function of survey area and redshift for both direct detection and intensity mapping surveys.
Closure Traces: Novel Calibration-insensitive Quantities for Radio Astronomy
Authors: Broderick Avery E. , Pesce Dominic W. 
Published: November 2020

Abstract
Closure phases and closure amplitudes have proven critical to modern radio interferometry due to their insensitivity to the uncertain station gains. We present the first set of closure quantities constructed from parallel-hand and cross-hand visibilities that are insensitive to both station gains and to polarimetric leakage. These complex “closure traces” are a natural extension of closure amplitudes and closure phases, are independent of all station-based linear corruptions of the polarized visibilities, and are complete in the sense that they contain all remaining information present in the visibility data. Products of closure traces on so-called “conjugate” quadrangles are sensitive only to structure in the source polarization fraction—independent of variations in the Stokes I structure—and thereby provide unambiguous probes of polarization in astronomical sources.
Developing Academic Thinking in the EFL Writing Classroom: A Rationale for General-academic Writing Assignments
Authors: Zalewski Jan 
Published: November 2020

With the evidence for disciplinary variation in academic discourse constantly growing, the idea of teaching core academic thinking in writing seems to have become increasingly problematic. The paper offers a rationale for two general-academic writing assignments, each focusing on teaching one fundamental aspect of what is defined as the intellectual stance underlying academic writing in general. The two aspects are problematizing and subject position. Problematizing and assuming a new subject position in the context of academic writing prove to be troublesome tasks for many entering college students. The assignments are designed to help students cope with these problems. They are based on a reactive approach rather than on modelling academic discourse, with the teacher helping students to reflect on their rendering of familiar experiences.
El vareo de bellotas: pervivencia de una técnica de recolección prehistórica en el bosque mediterráneo
Authors: García Gómez Enrique , Ruiz Taboada Arturo , Pereira Sieso Juan 
Published: November 2020

El vareo es una de las fases de la recolección de bellotas, frutos usados como alimento básico o como complemento de la dieta humana desde época prehistórica. Consiste en sacudir las ramas de la encina, u otras especies del género Quercus, sirviéndose de una vara de madera larga y flexible.
De esta herramienta no existen hasta el momento evidencias en el registro arqueológico debido a los materiales perecederos utilizados en su fabricación. Esta ausencia puede ser suplida con la información derivada tanto del estudio de la iconografía prehistórica e histórica como del registro etnográfico actual. En este artículo se analizan diversos ejemplos que van desde el Neolítico hasta la actualidad, que demuestran la pervivencia de esta milenaria práctica usada por las sociedades rurales de la Europa mediterránea.
Capacidad reproductiva de Nannochloropsis oculata en diferentes concentraciones de salinidad y fertilizante: Una contribución a la Bioeconomía acuícola
Authors: Osorio-Urtecho Katherinne del Rosario , Palacios-Sánchez Karen Mercedes , Lumbi-Ortega Dalia Mercedes , Hsieh Po Yuan , Zuniga-Gonzalez Carlos Alberto , Aguilar Ariel José 
Published: November 2020

El estudio se centró en contribuir a la Bioeconomía Acuícola evaluando el ritmo reproductivo de Nannochloropsis oculata en dos baterías experimentales con concentraciones salinas de 33 ‰, 25 ‰, 20 ‰, 15 ‰, 10 ‰ y 5 ‰. A cada una se le aplicó dosis únicas de 0.32 ‰ y 1 ‰ de F/2 Guillard, respectivamente. Se realizaron dos experimentos en tiempos de 10 y 23 días a temperatura de 25 ºC. El primer experimento con 0.32 ‰ de F/2 Guillard, N. oculata presentó mayor número de cel/ml en salinidades de 33 ‰ y 25 ‰, a los 8 días de estudio, denotando la afinidad de N. oculata de reproducirse con mayor velocidad en ese rango de salinidad. La importancia del uso de F/2 Guillard fue observada usando 1‰ debido a que la microalga presenta similar número de cel/ml (P≤0.05) en concentraciones salinas de 33 ‰, 25 ‰, 20 ‰ y 15 ‰ y similar concentración a las microalgas cultivadas con 0.32 ‰ de F/2 Guillard en salinidades de 33 ‰ y 25 ‰. La capacidad de N. oculata fue testado en un segundo experimento donde los resultados muestran similar número de cel/ml entre los tratamientos salinos, en ambas baterías, a los 23 días de cultivo. Los resultados muestran que N. oculata puede ser cultivada con bajas concentraciones de F/2 Guillard en rangos de salinidad entre 25 ‰ y 33 ‰, implica reducción de costos.
Staples "NOT ENOUGH OF THAT" and "NOT ENOUGH OF THAT": syntactic functions
Authors: Wang Xuejian 
Published: November 2020

The subject of the research in this article is a comparative characteristic of the introductory expressions "not enough" and "not enough of this", used as a means of communication, mainly in the text вЂ“ as text staples. The relevance of the research subject is determined by its involvement in the study of the linguistics of the text, in particular the linguistic units that perform binding functions in the text. The purpose of this study is to identify the features of the syntactic functions "not enough" and "not enough of this". In the course of the study, an introspective-inductive, descriptive and comparative method was used, which allowed us to deduce the features of the use of "not enough" and "not enough of this". В В The research is conditioned by the need to continue studying the text, ways to achieve its coherence, integrity and means of expression in context. The main conclusions of the study are that both clips are used in the following cases: firstly, as a text clip at the beginning of a statement; secondly, in the function of a phrase clip; thirdly, as a means of communication within a sentence - complex and simple. The most typical for both staples is the text clip function. The novelty of the study lies in the fact that for the first time a description of the introductory units "not enough" and "not enough of this" was created in the syntactic aspect.
Agro-Morphological Characterization of Three Cultivated Legumes: Two Varieties of Soybean (Glycine max L.) and One Variety of Mungbean (Vigna radiata L.)
Authors: Yao Koffi Bertin , Kouakou Kouassi Joseph , Yoboue Aya Viviane , Kouakou Tanoh Hilaire 
Published: November 2020

To contribute to the restoration of tropical soils fertility, the agro-morphological and yield characteristics of three cultivated legumes [two beige seeded varieties of soybean (Glycine max L.): one from Côte d’Ivoire (BVCI) and the other, from Benin (BVB) and a green seeded mungbean variety (Vigna radiata L) from Côte d'Ivoire (MVCI)] were studied. The legumes seeds were sown and the resulting plants were monitored until harvest. The data relating to the plants phenological, morphological and yield parameters were statistically processed through one-way analysis of variance (ANOVA 1). The results of phenological observations indicated that the mungbean (MVCI) was earlier than both soybean varieties (BVCI followed by BVB). Morphologically, plants of the late soybean varieties (BVCI and BVB) were higher, more branched with a large wingspan, and produced more panicles than the early variety of mungbean (MVCI). In addition, mungbean variety (MVCI) produced long tapered pods containing small seeds while the soybean varieties produced shorter but wider pods containing large seeds. In terms of yied, both late soybean varieties (BVCI and BVB) produced large dry biomass, more pods with higher seed yield, dry weight and 100 seed weight than the early variety of mungbean (MVCI).
Significance: The precocious nature of mungbean makes it an important plant for the fight against climate change, especially against drought. Due to their good branching and significant plant spread, both late varieties of soybean (BVCI and BVB) have high potential of being selected for soil protection and weed control, as well as for food production because of their high pod yield, seed and dry biomass.
Development and Validation of Simple, Rapid and Sensitive High- Performance Liquid Chromatographic Method for the Determination of Butenafine Hydrochloride
Authors: Ansari Mohammad Javed , Ahmed Mohammed Muqtader , Anwer Md. Khalid , Aldawsari Mohammed F. , Shahrani Saad M. Al , Ahmad Niyaz 
Published: November 2020

Aims: The current paper reports a simple, rapid, sensitive, accurate, and precise Reverse-phase high performance liquid chromatography (RP-HPLC) method with wide range of estimation to determine butenafine hydrochloride in nanosponges. This method has been validated as per ICH norms.
Study Design: Experimental design with influence of variables such as mobile phase composition, flow rate, temperature and wavelength on the chromatographic peaks.
Place and Duration of Study: Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia between Jan 2020 and March 2020.
Methodology: Separation was achieved by utilizing the most commonly used reverse phase column (C-18, 5 μm, 150 mm x 4.6 mm) set at 30ºC and quantified by UV detection at 280 nm after isocratic elution from a mobile phase (70:30 v/v of methanol: phosphate buffer pH 3.0) flowing at 1 ml/min.
Results: A sharp and symmetrical peak was observed at 4.08 ± 0.01 minutes. The low variation in peak area and retention time (1.12% and 0.29%, respectively) and a high number of theoretical plates (>2000) indicated this method’s efficiency and suitability. The least square linear regression analysis (Y = 9265.5 X + 1961.4) showed excellent correlation (r2 = 0.999 ± 0.0003) between concentration and peak area of butenafine hydrochloride through a wide concentration range of 1–50 µg/ml. The limits of detection and quantification (LOD and LOQ) were 0.18 µg/ml and 0.57 µg/ml, respectively. The assay or determinations were accurate, precise and reproducible with mean accuracy and mean relative standard deviation of precision of 101.53 ± 0.43% and 0.51 ± 0.11% respectively.
Conclusion: The developed RP-HPLC method was simple, sensitive, reproducible with wide range of estimation of butenafine hydrochloride in the nanosponges. The proposed method could be used for the analysis of butenafine hydrochloride in the conventional pharmaceutical formulations such as tablets, syrup, creams including novel formulations such as nanoparticles, nanosponges, nanoemulsions. The proposed method overcomes the specificity, sensitivity and reproducibility related issues of ultraviolet-visible spectroscopy.
Lifshitz Transition and Non‐Fermi Liquid Behavior in Highly Doped Semimetals
Authors: Kang Kyungrok , Kim Won June , Kim Dohyun , Kim Sera , Ji Byungdo , Keum Dong Hoon , Cho Suyeon , Kim Young‐Min , Lebègue Sébastien , Yang Heejun 
Published: November 2020

AbstractThe classical Fermi liquid theory and Drude model have provided fundamental ways to understand the resistivity of most metals. The violation of the classical theory, known as non‐Fermi liquid (NFL) transport, appears in certain metals, including topological semimetals, but quantitative understanding of the NFL behavior has not yet been established. In particular, the determination of the non‐quadratic temperature exponent in the resistivity, a sign of NFL behavior, remains a puzzling issue. Here, a physical model to quantitatively explain the Lifshitz transition and NFL behavior in highly doped (a carrier density of ≈1022 cm−3) monoclinic Nb2Se3 is reported. Hall and magnetoresistance measurements, the two‐band Drude model, and first‐principles calculations demonstrate an apparent chemical potential shift by temperature in monoclinic Nb2Se3, which induces a Lifshitz transition and NFL behavior in the material. Accordingly, the non‐quadratic temperature exponent in the resistivity can be quantitatively determined by the chemical potential shift under the framework of Fermi liquid theory. This model provides a new experimental insight for nontrivial transport with NFL behavior or sign inversion of Seebeck coefficients in emerging materials.
Achromatic Dielectric Metasurface with Linear Phase Gradient in the Terahertz Domain
Authors: Jia Ridong , Gao Yufei , Xu Quan , Feng Xi , Wang Qingwei , Gu Jianqiang , Tian Zhen , Ouyang Chunmei , Han Jiaguang , Zhang Weili 
Published: November 2020

AbstractThe notion of metasurface has inspired the innovation of various functional devices in the terahertz band, but the intrisinc dispersion restricts their application in broadband scenarios. Here, two terahertz achromatic linear‐phase‐gradient metasurface devices are demonstrated, which are a beam deflector and a beam splitter, respectively. The phase and dispersion of the metasurfaces are simultaneously engineered by changing the geometric parameters of the unit cells made of silicon gratings and pillars. The simulated and experimental results demonstrate the achromatic feasibility of the beam deflector from 0.6 to 1.2 THz and of the beam splitter from 0.6 to 1.1 THz. The transmittances and the splitting ratios of the achromatic beam splitter are also analyzed. The metasurface based achromatic beam deflector and splitter presented here not only enrich the terahertz functional devices, but the methods and structures may also promote the research of broadband terahertz metasurfaces.
Metal‐Free, Multicomponent Anti‐Markovnikov Hydroarylsulfonylation and Alkoxyarylsulfonylation of Vinyl Arenes
Authors: Das Pritha , Das Subhodeep , Varalaxmi Kasarla , Jana Ranjan 
Published: November 2020

AbstractA unified strategy for the hydro‐arylsulfonylation of vinyl arenes has been developed under catalyst, additive‐free conditions at room temperature from the corresponding aryldiazonium salts, DABSO (DABCO ⋅ 2SO2), and thiophenol as hydrogen atom transfer (HAT) reagent. Mechanistically, an incipient arylsulfonyl radical is generated from the corresponding aryl diazonium salts and DABSO which undergoes anti‐Markovnikov addition to styrenes followed by hydrogen atom transfer from thiophenol. Interestingly, this multi‐component reaction is highly chemoselective suppressing deleterious thiosulfonylation and thiol‐ene reactions. Tuning the reaction conditions, a four‐component difunctionalization with alkoxy group has been achieved using 1,4‐dicyanobenzene as an oxidant. Furthermore, base‐promoted elimination to form vinyl sulfone has been also examined. The practicability of this present reaction has been demonstrated by the ex situ generation of sulfur dioxide in an H‐type reaction vessel and subsequent hydro‐ and alkoxyarylsulfonylation in good to moderate yields. The hydroarylsulfonylation reaction is scalable and applied to a metal‐free synthesis of the key intermediate for an anti‐migraine drug Eletriptan.magnified image
Agricultural Trade Costs
Authors: Beghin John C. , Schweizer Heidi 
Published: November 2020

AbstractWe examine the recent evolution of salient trade costs in agricultural and food markets, and changes in their composition. We review ways to measure costs and provide guidance with policy prescriptions to reduce them. We pay attention to transportation costs, border measures, and standard‐like nontariff measures. By pointing out limitations in current approaches and recent developments, we aim to improve our understanding of their effects and derive clearer prescriptions. We suggest promising directions for further research and investigation of agricultural trade costs, including on the emerging debate on gene editing and trade, transportation costs, and mainstreaming recent advances in analyzing nontariff measures.
Unprecedented Crisis Calls for Unprecedented Policy Responses
Authors: Johansson Robert , Hungerford Ashley , Sewadeh Mirvat , Effland Anne 
Published: November 2020

AbstractThe COVID‐19 pandemic presented a severe crisis to the agricultural sector and the economy at large. To confront it, the administration and Congress had to mobilize vast resources very quickly and introduce creative emergency measures to mitigate the unprecedented impacts on the economy. This article takes a closer look at the impacts of the COVID‐19 pandemic on the agricultural sector and the policy measures that USDA implemented to help farmers and ranchers weather the immediate crisis.
Silflower seed and biomass responses to plant density and nitrogen fertilization
Authors: Schiffner Sydney , Jungers Jacob M. , Hulke Brent S. , Van Tassel David L. , Smith Kevin P. , Sheaffer Craig C. 
Published: November 2020

AbstractSilflower (Silphium integrifolium Michx.) is a potential perennial oilseed crop that can provide ecosystem services; however, its seed, oil, and biomass yield potential are unknown. Our objectives were to determine the effects of planting density and N fertilizer on silflower seed, oil, and biomass yields and seed yield components for 3 yr after establishment. Experiments tested six planting densities on two soil types, and five N rates and two planting densities on one soil type. Averaged over years and soil types, increasing planting density from 11,954 to 53,792 plants ha−1 increased biomass yield (BY), but decreased seed heads plant−1 and seeds plant−1. Planting density had no effect on seed yield (SY) or oil yield (OY), other seed related variables, or harvest index. On a sandy soil, SY and OY increased linearly with N rates from 0 to 180 kg ha−1 in the year after seeding but were not affected by N fertilization rates in subsequent years. At 180 kg N ha−1, SY, OY, and BY were 1,651 kg ha−1, 381 kg ha−1, and 10.5 Mg ha−1, respectively, in the year following seeding but declined thereafter. Over both experiments SY and OY were positively correlated (r = .99) and together associated with seed heads plant−1, seeds head−1, and seeds plant−1. Relative to annual oilseed crops, seed and oil yields for this new perennial species are low. Germplasm improvement for seed and oil yield and agronomic research to maintain yields as stands age are critical to develop this new perennial oilseed crop.