bluuebunny/crossref_metadata_2025_split huggingface dataset:
275 Candidates and 149 Validated Planets Orbiting Bright Stars in K2 Campaigns 0–10
Authors: Mayo Andrew W. , Vanderburg Andrew , Latham David W. , Bieryla Allyson , Morton Timothy D. , Buchhave Lars A. , Dressing Courtney D. , Beichman Charles , Berlind Perry , Calkins Michael L. , Ciardi David R. , Crossfield Ian J. M. , Esquerdo Gilbert A. , Everett Mark E. , Gonzales Erica J. , Hirsch Lea A. , Horch Elliott P. , Howard Andrew W. , Howell Steve B. , Livingston John , Patel Rahul , Petigura Erik A. , Schlieder Joshua E. , Scott Nicholas J. , Schumer Clea F. , Sinukoff Evan , Teske Johanna , Winters Jennifer G. 
Published: March 2018

Abstract
Since 2014, NASA’s K2 mission has observed large portions of the ecliptic plane in search of transiting planets and has detected hundreds of planet candidates. With observations planned until at least early 2018, K2 will continue to identify more planet candidates. We present here 275 planet candidates observed during Campaigns 0–10 of the K2 mission that are orbiting stars brighter than 13 mag (in Kepler band) and for which we have obtained high-resolution spectra (R = 44,000). These candidates are analyzed using the vespa package in order to calculate their false-positive probabilities (FPP). We find that 149 candidates are validated with an FPP lower than 0.1%, 39 of which were previously only candidates and 56 of which were previously undetected. The processes of data reduction, candidate identification, and statistical validation are described, and the demographics of the candidates and newly validated planets are explored. We show tentative evidence of a gap in the planet radius distribution of our candidate sample. Comparing our sample to the Kepler candidate sample investigated by Fulton et al., we conclude that more planets are required to quantitatively confirm the gap with K2 candidates or validated planets. This work, in addition to increasing the population of validated K2 planets by nearly 50% and providing new targets for follow-up observations, will also serve as a framework for validating candidates from upcoming K2 campaigns and the Transiting Exoplanet Survey Satellite, expected to launch in 2018.
Exploring students’ reflective writing on Facebook
Authors: Annamalai Nagaletchimee , Jaganathan Paramaswari 
Published: March 2018

<p>According to our experience, facilitating online reflective writing via Facebook motivates students to improve their writing skills and reflective thinking. Six students and a teacher from an urban school in the northern region of Malaysia were involved in this study. The qualitative data in the form of online archives were categorized as reflection-in-action (feedback and self-correction) based on Garrison et al.'s (2000) cognitive presence. Additionally, reflection-on-action which comprised the students’ reflective journal demonstrated their thoughts and feelings while engaged in the Facebook environment. Data suggested that feedback only related to grammar and sentence structures (micro aspects). There was no feedback relating to organization and content (macro aspects). The reflective journal revealed that Facebook can be considered as a successful platform to enhance students’ narrative writing. The findings of this study have implications for teaching and learning activities in web-based environments. </p>
Dosificación de hormigón autocompactante reforzado con fibras de acero basado en el estudio de la reología de la pasta
Authors: Poveda Bautista Elisa , De la Rosa Velasco Angel , Cifuentes Bulte Héctor , Ruiz López Gonzalo 
Published: March 2018

Se presenta una metodología de diseño de hormigón autocompactante reforzado con fibras de acero (HACRFA) basada en la resistencia a compresión y en la viscosidad plástica efectiva buscadas para dicho hormigón. Además, se incorporan los valores de la fracción en volumen de fibra y esbeltez como datos necesarios para implementar el método. Se trata de un procedimiento sencillo y útil ya que mediante unas cartas de diseño se calculan las proporciones de los diferentes componentes del HACRFA. Su fundamento parte de la propuesta de diseño para hormigón autocompactante (HAC) desarrollada y validada experimentalmente por Abo Dhaheer et al. (Journal of Sustainable Cement-Based Materials 5(4): 199-216, 217-232, 2016), basada en los valores de resistencia a compresión y viscosidad plástica deseados, y se adapta para la incorporación de fibra de acero por medio de la ecuación obtenida por Ghanbari y Karihaloo (Cement and Concrete Research 39: 1209-1216, 2009), que aproxima con precisión el valor de la viscosidad plástica efectiva del HACRFA. A partir de modelos constitutivos micromecánicos se puede estimar el valor de la viscosidad plástica efectiva del HACRFA por medio de la viscosidad plástica de la pasta de cemento. Ésta se puede medir fácilmente utilizando instrumentos de bajo coste, como un viscosímetro capilar, aunque aquí la presentamos tabulada para diferentes tipologías de cemento, adiciones y relaciones agua-materiales cementíceos. Las ecuaciones implicadas en el procedimiento conducen a unas cartas de diseño de fácil interpretación y uso que permiten establecer las cantidades de componentes del hormigón. Estas cartas de diseño son específicas para cada resistencia a compresión objetivo. Además, esta metodología asume que la resistencia a compresión en un hormigón reforzado con fibras no cambia significativamente para cuantías bajas de fibra, lo cual es cierto, según el tipo de fibra, hasta aproximadamente un 1% en volumen.Finalmente, se aporta la validación experimental de esta metodología para HACRFA de diferentes resistencias, obteniendo unos valores de resistencia a compresión a 28 días y viscosidad semejantes a los predichos por el método.DOI: http://dx.doi.org/10.4995/HAC2018.2018.5645
Determinación de la absorción de energía del hormigón reforzado con fibras mediante el ensayo de panel EFNARC y el ensayo Barcelona
Authors: Carmona Malatesta Sergio Alejandro , Molins Climent 
Published: March 2018

Durante los últimos años, en muchos proyectos que se ejecutan en Chile, para el control de calidad de los hormigones proyectados reforzados con fibras usados para el sostenimiento de túneles se utiliza la capacidad de absorción de energía, determinada con el ensayo de panel EFNARC. Sin embargo, este ensayo requiere muestras relativamente grandes y pesadas que se llenan durante la proyección de hormigón. Esta práctica no permite probar el hormigón realmente colocado. Además, se ha observado que el modo de falla de los paneles está influido por diferentes factores que afectan en el resultado obtenido. Por el contrario, el ensayo Barcelona es un ensayo de tracción indirecta que ha demostrado ser adecuado para el control de calidad de hormigón reforzado con fibra y que puede ser implementado en las obras de construcción de túneles debido: a su simplicidad y facilidad de ejecución, al uso de una probeta pequeña con alta superficie de fractura y a la baja dispersión de los resultados. En este artículo se establece una correlación entre la capacidad de absorción de energía del hormigón reforzado con fibra determinada mediante el ensayo de panel EFNARC con la energía disipada en el ensayo Barcelona, con el objetivo de utilizar este ensayo para el control en obras de construcción de túneles.​DOI: http://dx.doi.org/10.4995/HAC2018.2018.5668
Use of seaweed Ulva lactuca for water bioremediation and as feed additive for white shrimp Litopenaeus vannamei
Authors: Elizondo-González Regina , Quiroz-Guzmán Eduardo , Escobedo-Fregoso Cristina , Magallón-Servín Paola , Peña-Rodríguez Alberto 
Published: March 2018

Two experimental feeding trials were conducted during four weeks to evaluate the use of Ulva lactuca in shrimp culture: (1) for wastewater bioremediation, and (2) using different inclusion levels of U. lactuca meal in shrimp feed. In feeding trial 1, shrimp reared under seaweed U. lactuca water exchange in a re-circulation system (SWE) resulted in similar growth and feed utilization as shrimp reared with clean water exchange (CWE). Shrimp under no water exchange (NWE) resulted in significant lower growth and higher feed conversion rate (FCR) compared to the other treatments (p < 0.05). Nitrogen compounds and phosphate in water from SWE and CWE treatments did not present significant differences during the experimental trial (p > 0.05). In feeding trial 2, U. lactuca biomass produced by wastewater bioremediation in SWE treatment were dried and ground to formulate diets containing 0, 1, 2, and 3% U. lactuca meal (0UL, 1UL, 2UL, and 3UL). Shrimp fed the 3 UL diet resulted in a significant (p < 0.05) improvement of growth and FCR, and enhanced whole shrimp lipid and carotenoid content by 30 and 60%, respectively, compared to control diet. Seaweed U. lactuca is suggested as a desirable species for wastewater bioremediation in integrated aquaculture systems, and its meal as a good feed additive for farmed shrimp.
Evidence for Gravity Wave Seeding of Convective Ionospheric Storms Possibly Initiated by Thunderstorms
Authors: Kelley M. C. , Dao E. V. 
Published: March 2018

AbstractWith the increase in solar activity, the Communication/Outage Forecast System satellite decayed on orbit to below the F peak. As such, we can study the development of convective ionospheric storms and, most importantly, study large‐scale seeding of the responsible instability. For decades, gravity has been suggested as being responsible for the long wavelengths in the range of 200 to 1,000 km, as are commonly observed using airglow and satellite data. Here we suggest that convective thunderstorms are a likely source of gravity waves and point out that recent theoretical analysis has shown this connection to be quite possible.
Diurnal Variations in Global Joule Heating Morphology and Magnitude Due To Neutral Winds
Authors: Billett D. D. , Grocott A. , Wild J. A. , Walach M.‐T. , Kosch M. J. 
Published: March 2018

AbstractIn the polar ionosphere, variations in Joule heating are significantly controlled by changes in plasma convection, such as that brought about by changes in the interplanetary magnetic field. However, another important consideration when calculating Joule heating is the velocity difference between this plasma and the neutral thermosphere colocated with the ionosphere. Neutral wind data are often difficult to obtain on a global scale; thus, Joule heating has often previously been calculated assuming that neutral velocities are small and can therefore be neglected. Previous work has shown the effect of neutral winds on Joule heating estimations to be more significant than originally thought; however, the diurnal variations of the neutrals due to changes in solar pressure gradients and Coriolis forces have yet to have their impact on Joule heating assessed. We show this universal time effect to be significant in calculating Joule heating and thus can differ significantly from that calculated by neglecting the neutrals. In this study, we use empirical models for the neutral wind, conductivities, and magnetic field to create Northern Hemispheric patterns of Joule heating for approximately 800,000 individual plasma convection patterns generated using data from the Super Dual Auroral Radar Network. From this, a statistical analysis of how Joule heating varies in morphology and magnitude with universal time is shown for differing seasons and levels of geomagnetic activity. We find that neutral winds do play a significant role in the morphology and total energy output of Joule heating.
QBO‐MJO Connection
Authors: Zhang Chidong , Zhang Bosong 
Published: March 2018

AbstractActivities of the Madden‐Julian Oscillation (MJO) in boreal winter has recently been found to be stronger in easterly phases of the stratospheric quasi‐biennial oscillation (QBO) than its westerly phases. This QBO‐MJO connection was investigated in this study using a method that identifies individual MJO events by tracking their eastward propagating signals in precipitation. Stronger MJO activities in QBO easterly phases are a consequence of more MJO days, not larger amplitudes of individual MJO events as previously thought. More MJO days come from more MJO events initiated over the Indian Ocean and their longer duration because of a weaker barrier effect of the Maritime Continent on MJO propagation. Zonal heterogeneity exists in the connection between QBO, MJO, and tropical total precipitation in general. This poses a challenge to our current understanding of the MJO dynamics, which has yet to fully include upper‐tropospheric and stratospheric processes.
Iodine(III) Reagent‐Mediated Intramolecular Amination of 2‐Alkenylanilines to Prepare Indoles
Authors: Zhao Chun‐Yang , Li Kun , Pang Yu , Li Jia‐Qing , Liang Cui , Su Gui‐Fa , Mo Dong‐Liang 
Published: March 2018

AbstractA variety of 3‐substituted and 2,3‐disubstituted indoles were synthesized efficiently in good yields through the intramolecular amination of 2‐alkenylanilines promoted by readily available iodine(III) reagents in a short reaction time. Mechanistic studies showed that the reaction pathway went through a nitrenium ion and that 3‐acetoxy indoline was the key intermediate in the indole formation. The indole product was easily prepared on a gram scale and amination also proceeded smoothly using catalytic 3,5‐dimethylphenyl iodine in the presence of mCPBA. Furthermore, the indolo[3,2‐a]carbazole scaffold was prepared in good yield in six steps from commercial ortho‐iodoaniline.magnified image
Chiral Ion‐Pair Organocatalyst‐Promoted Efficient Enantio‐selective Reduction of α‐Hydroxy Ketones
Authors: Zhang Yiliang , He Li , Shi Lei 
Published: March 2018

AbstractThe enantioselective reduction of α‐hydroxy ketones with catecholborane has been developed employing 5 mol% of an 1,1′‐bi‐2‐naphthol (BINOL)‐derived ion‐pair organocatalyst. This methodology provides a straightforward access to the corresponding aromatic 1,2‐diols in high yields (up to 90%) with excellent enantioselectivities (up to 97%). Furthermore, the α‐amino ketones also could be reduced with moderate ee values under mild reaction condition.magnified image
Can we build it? Yes we can, but should we use it? Assessing the quality and value of a very large phylogeny of campanulid angiosperms
Authors: Beaulieu Jeremy M. , O'Meara Brian C. 
Published: March 2018

Premise of the StudyThe study of very large and very old clades holds the promise of greater insights into evolution across the tree of life. However, there has been a fair amount of criticism regarding the interpretations and quality of studies to date, with some suggesting that detailed studies carried out on smaller, tractable scales should be preferred over the increasingly grand syntheses of these data.MethodsWe provided in detail our trials and tribulations of compiling a large, sparsely sampled matrix from GenBank data and inferring a well‐supported, time‐calibrated phylogeny of Campanulidae. We also used a simulation approach to assess tree quality and to study the value of using very large, comprehensive phylogenies in a comparative context.Key ResultsA robust and well‐supported phylogeny can be produced as long as automated procedures are supplemented with some human intervention. In the case of campanulids, the overall topology may be driven not only by particular genes, but also particular sequences for a gene. We also determined that estimates of divergence times should be fairly robust to issues related to clade‐specific heterogeneity. Finally, we demonstrated how relying on results from smaller, younger clades are prone to produce biased interpretations of tropical to temperate evolution across campanulids as a whole.ConclusionsWhile we were both surprised and encouraged by the robust and fairly well‐resolved, comprehensive phylogeny of campanulids, challenges still remain. Nevertheless, large phylogenies are inherently valuable in a comparative context if only to attenuate the issue of ascertainment bias.
N‐Alkylation of Aqueous Ammonia with Alcohols Leading to Primary Amines Catalyzed by Water‐Soluble N‐Heterocyclic Carbene Complexes of Iridium
Authors: Fujita Ken‐ichi , Furukawa Shohichi , Morishima Namino , Shimizu Mineyuki , Yamaguchi Ryohei 
Published: March 2018

AbstractA new catalytic system for the N‐monoalkylation of aqueous ammonia with a variety of alcohols was developed. Water‐soluble dicationic complexes of iridium bearing N‐heterocyclic carbene and diammine ligands exhibited high catalytic activity for this type of reaction on the basis of hydrogen‐transfer processes without generating harmful or wasteful byproducts. Various primary amines were efficiently synthesized by using safe, inexpensive, and easily handled aqueous ammonia as a nitrogen source. For example, the reaction of 1‐(4‐methylphenyl)ethanol with aqueous ammonia in the presence of a water‐soluble N‐heterocyclic carbene complex of iridium at 150 °C for 40 h gave 1‐(4‐methylphenyl)ethylamine in 83 % yield.
Green Organocatalytic Oxidative Methods using Activated Ketones
Authors: Triandafillidi Ierasia , Tzaras Dimitrios Ioannis , Kokotos Christoforos G. 
Published: March 2018

AbstractAlkenes are very important moieties in organic chemistry and have been employed as starting materials for the synthesis of important organic compounds. In this review, we present organocatalytic reactions in which alkenes play a central role, especially their organocatalytic oxidation to epoxides. This topic plays a pivotal role in our recent research, for which we utilize H2O2 as a green oxidant and a ketone as the catalyst. Extension to other oxidative transformations is also presented.
Computing Crystal Size Distribution by Focused‐Beam Reflectance Measurement when Aspect Ratio Varies
Authors: Unno Joi , Umeda Ryuta , Hirasawa Izumi 
Published: March 2018

AbstractChord length distribution (CLD) can be determined by an in‐line measuring system with focused‐beam reflectance measurement, but it can differ from crystal size distribution (CSD). However, expected values of CLD can be calculated from CSD by statistical methods and vice versa. In this study, a correlation equation between crystal size and aspect ratio during cooling crystallization was obtained and a mapping matrix was calculated based on the correlation equation. Then, the suspension obtained in cooling crystallization was sampled and CSDs were measured by microscopy at the same time that CLDs were measured with FBRM. As a result of error evaluation, transformation of CLD into CSD reduced the errors between CLDs and CSDs except in the early stage of crystallization.
Antisolvent Crystallization of Polymorphs of L‐Histidine
Authors: Punmalee Neeranuch , Wantha Lek , Flood Adrian E. 
Published: March 2018

AbstractAntisolvent crystallization is the most common method to study solvent effects on polymorphic crystallization. L‐Histidine (L‐his) served as a model substance. Acetonitrile, acetone, and methanol were selected as antisolvents, with water as solvent. The formation of L‐his polymorphs in antisolvent crystallization as a function of supersaturation, antisolvent volume fraction, and temperature was studied. The solubility of polymorph A of L‐his decreased with increasing volume fraction of antisolvent and increased with higher temperature. The metastable polymorph B of L‐his was obtained at higher antisolvent volume fraction and supersaturation. At lower antisolvent volume fraction and supersaturation, a mixture of polymorphs A and B was detected.
Long‐term record of Argentine ant invasions reveals enduring ecological impacts
Authors: Menke Sean B. , Ward Philip S. , Holway David A. 
Published: March 2018

AbstractThe ecological effects of species introductions can change in magnitude over time, but an understanding of how and why they do so remains incompletely understood. Clarifying this issue requires consideration of how temporal variation in invader traits affects invasion impacts (e.g., through differential effects on the diversity and composition of native species assemblages). We examine the temporal dynamics of Argentine ant invasions in northern California by resurveying 202 sites first sampled 30–40 yr ago. To test how invasion impacts change over time, we estimated native ant richness and species composition at 20 riparian woodland sites that span a 30‐yr invasion chronosequence. We then use these data to test how variation in two invader traits (aggression and relative abundance) is related to time since invasion and invasion impact. Native ant assemblages along the chronosequence exhibited reduced native ant richness and altered species composition (compared to uninvaded control sites), but the magnitude of these impacts was independent of time since invasion. These results are corroborated by additional temporal comparisons of native ant assemblages at riparian sites sampled 20–30 yr ago. Our findings together illustrate that the impacts of invasions can persist undiminished over at least a 30‐yr time frame and remain evident at regional scales. Although neither invader trait varied with time since invasion, native ant richness declined as the relative abundance of the Argentine ant increased. This latter result supports the hypothesis that factors reducing invader abundance at particular sites can decrease invasion impacts, but also that such changes may be due to site‐specific factors (e.g., abiotic conditions) that affect invader abundance rather than time since invasion per se. Future studies should attempt to differentiate factors that are intrinsic to the process of invasion (e.g., changes in invader populations) from long‐term environmental changes (e.g., climate change) that represent extrinsic influences on the dynamics of invasion.
The volume and type of unhealthy bus shelter advertising around schools in Perth, Western Australia: Results from an explorative study
Authors: Parnell Ashleigh , Edmunds Melinda , Pierce Hannah , Stoneham Melissa J. 
Published: March 2018

AbstractIssue addressedExposure to advertising for unhealthy food, alcohol and gambling has been shown to influence children and adolescents’ behaviours and attitudes. This exploratory study aimed to assess the volume and type of unhealthy bus shelter advertisements near schools in five local government areas in Perth, Western Australia and to monitor whether the volume of unhealthy advertisements varied seasonally.MethodsThe 29 local governments in the Perth metropolitan region were contacted seeking information regarding the locations of bus shelters featuring advertisements in their local government area. Five local governments provided sufficient information for an audit of the bus shelter advertisements in their area to be conducted.Every bus shelter within 500 m of a school was photographed and the type of advertisement recorded. The advertisements in the food, non‐alcoholic beverage, alcohol, or gambling categories were then classified as being healthy, moderate, or unhealthy. This process was carried out in June, September, December 2016, and March 2017 to ascertain whether the type of advertisements displayed changed depending on the season.ResultsOf the 293 advertisements recorded over the four audits, 31% featured unhealthy products, 3% moderate, and <1% healthy. Only two of the 293 advertisements were classified as being healthy. Seasonal variation in the volume of unhealthy advertisements was not identified.So what?Western Australian school students are regularly exposed to unhealthy bus shelter advertisements. Stricter regulation of outdoor advertising is needed to ensure that young people are protected from the influence of unhealthy industries.