bluuebunny/crossref_metadata_2025_split huggingface dataset:
PENGARUH MEDIA TANAM TERHADAP RESPON FISIOLOGI AKLIMATISASI ANGGREK Cattleya
Authors: Andriani V. , Pramushinta I. A.K. 
Published: May 2020

Cattleya included in the family Orchidaceae that can be grown using tissue culture methods. Adjustments to the climate into a new environment, known as acclimatization is an important issue when cultivating the plant seedlings are propagated by tissue culture techniques. This study aims to determine the acclimatization media (wood charcoal, husk charcoal, moss and cocopeat ) suitable for a physiological response (weight of the plant and chlorophyll content) Cattleya tissue culture results. Measurement of chlorophyll content using a spectrophotometer. Results obtained in the form of quantitative. Data analysis using ANAVA with SPSS 16 Software. Results showed that rice husk media has a great influence over the weight and chlorophyll content acclimatization Cattleya.

Keywords: Cattleya, Acclimatization, Media
PERTUMBUHAN DAN HASIL PANEN TANAMAN JAGUNG (Zea mays) VARIETAS LOKAL DAN HIBRIDA YANG DI INFEKSI CENDAWAN Fusarium sp
Authors: Trifatmawati D.A. , Sopandi Tatang 
Published: May 2020

The aim of this study to prove the effect of Fusarium sp fungus infection on corn (Zea mays) to the growth and yield of local corn varieties and hybrid corn varieties. After the age of 45 HST treatment done 5 polybags of plants local corn varieties and 5 polybags of plant hybrid corn varieties infected with Fusarium sp fungus and 5 polybags of plants local corn varieties and 5 polybags of plant hybrid corn varieties not infected by fungus Fusarium sp. The result showed that treatment infected of Fusarium sp and without Fusarium sp fungus significant (P <0,05) to growth and yield of local varieties and hybrid varieties of corn. The average height of local varieties and hybrid varieties of corn with infected by Fusarium sp significant (P <0.05) was lower than the height of corn without Fusarium sp fungus. Local and hybrid varieties of corn after being infected with Fusarium sp fungus showed results significant of leaf with. The yield of corn and the weight of kernel that has been shell showed treatment of Fusarium sp (F5) fungus significant (P <0,05) was lower than the yield of corn not infected by Fusarium sp. The results of this study can be concluded that infections of Fusarium sp fungus on local varieties and hybrid varieties have an influence on growth and yield.

Keyword : Corn, Fusarium sp, growth and yield
Resolução de problemas contextualizados: análise de uma ação didática para o ensino de matemática nos anos iniciais do ensino fundamental
Authors: Souto Flavia Cristine Fernandes , Guérios Ettiène 
Published: May 2020

O presente artigo advém de uma pesquisa qualitativa de natureza interpretativa e teve entre seus objetivos investigar como problemas matemáticos contextualizados possibilitam a construção de estratégias de resolução a partir da interpretação e compreensão de seus enunciados. A pesquisa foi desenvolvida em duas turmas do 4º ano do Ensino Fundamental de uma escola pública do município de Curitiba (PR). O contexto foi criado a partir de sugestões dos alunos por meio de levantamento de interesse, que após sistematizados resultaram em um tema coletivo para as duas turmas. Problemas contextualizados foram criados em episódios encadeados, que foram resolvidos pelos alunos em seis encontros, sendo alguns em grupo e outros individualmente. Os processos de resoluções foram registrados por escrito e os diálogos gravados em áudio e vídeo. Concomitante a análise das resoluções, alunos foram entrevistados para esmiuçar estratégias resolutivas por eles elaboradas. Os resultados evidenciaram que o uso de temas de interesse dos alunos como base para a contextualização de problemas matemáticos contribuiu para o desenvolvimento de uma postura investigativa dos alunos, favoreceu a interpretação dos enunciados dos problemas possibilitando a percepção de relações matemáticas neles envolvidas e contribuiu para a aprendizagem conceitual dos conteúdos matemáticos curriculares.
O Ensino-Aprendizagem do Cálculo Diferencial e Integral através da Resolução de Problemas no Curso de Engenharia Civil
Authors: Nunes Célia Barros , Espíndola Reis Minervina Joseli , Ferreira Luanne Lima , Silva Leonardo Brito da 
Published: May 2020

O ensino do Cálculo Diferencial e Integral (CDI) tem sido foco de diversas discussões e investigações no campo da Educação Matemática a nível do Ensino Superior em função das dificuldades apresentadas pelos alunos na sua aprendizagem. Inserido neste contexto, este artigo apresenta parte de uma pesquisa desenvolvida com alunos de um curso de Engenharia Civil que teve como objetivo principal investigar o uso da Metodologia de Ensino-Aprendizagem-Avaliação de Matemática através da Resolução de Problemas na compreensão do Cálculo Diferencial e Integral, sobretudo no estudo da Otimização no curso de Engenharia Civil. Na construção do artigo, é apresentado um sucinto histórico da metodologia Resolução de Problemas ao longo dos anos, bem como uma breve discussão do ensino de Cálculo Diferencial e Integral nos cursos de Engenharia. Numa abordagem qualitativa, que tem como característica a descrição e interpretação dos dados coletados, foram utilizados como instrumentos de coleta de dados fotos e registros escritos das resoluções produzidas pelos alunos. A partir da análise dos dados, é possível afirmar que os estudantes compreenderam o significado da utilização do Cálculo e que o uso da Metodologia de Ensino-Aprendizagem-Avaliação de Matemática através da Resolução de Problemas no curso de Engenharia Civil permite ao aluno a oportunidade de investigar, de refletir e de analisar os problemas propostos.
La innovacion disruptiva y la formacion de las competencias del siglo XXI en las universidades de América Latina. Adiós al modelo educativo dominante
Authors: Robert Ricardo I. 
Published: May 2020

La innovación disruptiva es un cambio radical en un área determinada de la producción material o de la prestación de servicios en la sociedad. En pleno siglo XXI la humanidad está siendo testigo de una innovación disruptiva, especialmente en el campo tecnológico. El modelo educativo dominante marcha a la zaga en comparación con los cambios tecnológicos. Este artículo profundiza en el tema y trata de generalizar algunas ideas relativas a la Innovación disruptiva en la enseñanza y aprendizajes universitarios.
Molecular Response of Chronic Myeloid Leukaemia Patients to Tyrosine Kinase Inhibitors
Authors: Hossain Md. Imran , Yamani Md. Jaki , Hossain Md. Golzar , Hossain Mohammed Murad , Khan Md. Rafiquzzaman , Aziz Md. Abdul 
Published: May 2020

Background: The goal of therapy in Chronic Myeloid Leukaemia (CML) with tyrosine kinase inhibitors (TKIs) has been to achieve the molecular responses, as measured by the reduction or elimination of BCR-ABLl transcript. Objective: The aim of the study is to observe the molecular response status of CML patients to TKIs. Methodology: This is an observational study and was conducted in the department of Haematology, Bangabandhu Sheikh Mujib Medical University (BSMMU) from February 2018 to January 2019. A total of 30 diagnosed CML patients on TKIs therapy was checked for quantitative BCR-ABL1 (by qRT-PCR) level. The laboratory monitoring of BCR-ABL1 RNA with RQ-PCR was likely become the model for successful molecular diagnostic monitoring of CML patients to both assess and prognosticate the efficacy of these targeted treatments. Result: Among 30 diagnosed CML patients, the mean age was found 36.1±11.7 years with range from 20 to 70 years. Males were predominant 19 (63.3%), male: female ratio was 1.7:1. Almost two third (63.3%) patients were found optimal (?10%) after 3-month BCR ABL. Age, sex, religion, marital status, occupational status, BMI, monthly income, number of family member, symptoms and sings were not statistically significant (p>0.05) when compared between BCR ABL optimal (?10%) and warning (>10%) group. Mean haemoglobin, total leukocyte count, platelet count, basophil, myelocyte and baseline BCR
ABL1 were not statistically significant (p>0.05) however atypical cells was found statistically significant
(p
Residential mobility in Australia and the United States: a retrospective study
Authors: Bernard Aude , Forder Peta , Kendig Hal , Byles Julie 
Published: May 2020

Background: Levels of internal migration vary significantly between countries. Australia and the United States consistently record among the highest levels of migration anywhere in the world. Very little is known, however, about the factors underlying mobility differentials. We argue that this is because existing evidence is almost exclusively based on period measures applied to cross-sectional data.
Aims: We seek to advance understanding of cross-national variations in levels of residential mobility by drawing on a newly proposed suite of cohort migration measures, coupled with the recent release of internationally comparable retrospective residential history data.
Data and methods: Focusing on the early cohort of baby boomers born between 1947 and 1951, the paper examines residential mobility levels and patterns in early and mid-adulthood in Australia and the United States and compares them with 14 European countries. Differences in completed levels of residential mobility are assessed in terms of four components: the proportion of a cohort who moved at least once; mean age at first move; mean age at last move; and average interval between moves.
Results: While cohort analysis confirms high levels of mobility in Australia and the United States, it does not support the notion of a common ‘new world’ mobility regime distinct from other advanced economies.
Conclusion: A cohort perspective offers refined insights into population mobility. The increasing availability of retrospective survey data means that researchers can now apply cohort measures to a wide range of countries.
Suspended and Restored Activities of a Nearby Supermassive Black Hole
Authors: Wang J. , Xu D. W. , Sun S. S. , Feng Q. C. , Li T. R. , Xiao P. F. , Wei J. Y. 
Published: May 2020

Abstract
The discovery of spectral type transition of active galactic nuclei (AGNs), the so-called “changing-look” (CL) phenomenon, challenges the widely accepted AGN paradigm, not only in the orientation-based unified model, but also in the standard disk model. In past decades, only a couple of nearby repeat changing-look active galactic nuclei (CL-AGNs) have been identified. Here we report spectroscopic observations of UGC 3223 over the course of 18 yr, from 2001 onwards. Combining the spectrum taken in 1987 by Stirpe, we have witnessed its type transitions from

over 32 yr, and captured a long-lived (at least 10 yr) thorough “turn-off” state with a spectrum typical of a Seyfert 2 galaxy. The long-term thorough turn-off state probably suggests a once-dormant and an awakening central engine in UGC 3223. We argue that the (dis)appearance of the broad Balmer emission lines can be explained by the disk–wind broad-line region model given the evolution of the calculated Eddington ratio of accretion of the supermassive black hole.
HD 165054: An Astrometric Calibration Field for High-contrast Imagers in Baade’s Window
Authors: Nguyen Meiji M. , De Rosa Robert J. , Wang Jason J. , Esposito Thomas M. , Kalas Paul , Graham James R. , Macintosh Bruce , Bailey Vanessa P. , Barman Travis , Bulger Joanna , Chilcote Jeffrey , Cotten Tara , Doyon Rene , Duchêne Gaspard , Fitzgerald Michael P. , Follette Katherine B. , Gerard Benjamin L. , Goodsell Stephen J. , Greenbaum Alexandra Z. , Hibon Pascale , Hom Justin , Hung Li-Wei , Ingraham Patrick , Konopacky Quinn , Larkin James E. , Maire Jérôme , Marchis Franck , Marley Mark S. , Marois Christian , Metchev Stanimir , Millar-Blanchaer Maxwell A. , Nielsen Eric L. , Oppenheimer Rebecca , Palmer David , Patience Jennifer , Perrin Marshall , Poyneer Lisa , Pueyo Laurent , Rajan Abhijith , Rameau Julien , Rantakyrö Fredrik T. , Ren Bin , Ruffio Jean-Baptiste , Savransky Dmitry , Schneider Adam C. , Sivaramakrishnan Anand , Song Inseok , Soummer Remi , Tallis Melisa , Thomas Sandrine , Wallace J. Kent , Ward-Duong Kimberly , Wiktorowicz Sloane , Wolff Schuyler 
Published: May 2020

Abstract
We present a study of the HD 165054 astrometric calibration field that has been periodically observed with the Gemini Planet Imager (GPI). HD 165054 is a bright star within Baade’s Window, a region of the galactic plane with relatively low extinction from interstellar dust. HD 165054 was selected as a calibrator target due to the high number density of stars within this region (∼3 stars per square arcsecond with H < 22), necessary because of the small field of view of the GPI. Using nine epochs spanning over five years, we have fit a standard five-parameter astrometric model to the astrometry of seven background stars within close proximity to HD 165054 (ρ < 2″). We achieved a proper motion precision of ∼0.3 mas yr−1 and constrained the parallax of each star to be ≲1 mas. Our measured proper motions and parallax limits are consistent with the background stars being a part of the galactic bulge. Using these measurements, we find no evidence of any systematic trend of either the plate scale or the north angle offset of GPI between 2014 and 2019. We compared our model describing the motions of the seven background stars to observations of the same field in 2014 and 2018 obtained with Keck/NIRC2, an instrument with excellent astrometric calibration. We find that the predicted position of the background sources is consistent with that measured by NIRC2, within the uncertainties of the calibration of the two instruments. In the future, we will use this field as a standard astrometric calibrator for the upgrade of GPI and potentially for other high-contrast imagers.
Wide-band Rotation Measure Synthesis
Authors: Pratley Luke , Johnston-Hollitt Melanie 
Published: May 2020

Abstract
Rotation measure synthesis allows the estimation of Faraday dispersion via a Fourier transform and is the primary tool to probe cosmic magnetic fields. We show this can be considered mathematically equivalent to the one-dimensional (1D) interferometric intensity measurement equation, albeit in a different Fourier space. As a result, familiar concepts in 2D intensity interferometry designed to correctly account for a range of instrumental conditions can be translated to the analysis of Faraday dispersion. In particular, we show how to model the effect of channel averaging during Faraday reconstruction, which has to date limited the progress of polarimetric science using wide-band measurements. Further, we simulate 1D sparse reconstruction with channel averaging for realistic frequency coverages, and show that it is possible to recover signals with large rotation measure values that were previously excluded from possible detection. This is especially important for low-frequency and wide-band polarimetry. We extended these ideas to introduce mosaicking in Faraday depth into the channel-averaging process. This work thus provides the first framework for correctly undertaking wide-band rotation measure synthesis, including the provision to add data from multiple telescopes, a prospect that should vastly improve the quality and quantity of polarimetric science. This is of particular importance for extreme environments that generate high magnetic fields such as those associated with pulsars and fast radio bursts, and will allow such sources to be accurately used as probes of cosmological fields.
Propulsion of Spacecraft to Relativistic Speeds Using Natural Astrophysical Sources
Authors: Lingam Manasvi , Loeb Abraham 
Published: May 2020

Abstract
In this paper, we explore from a conceptual standpoint the possibility of using natural astrophysical sources to accelerate spacecraft to relativistic speeds. We focus on light sails and electric sails, which are reliant on momentum transfer from photons and protons, respectively, because these two classes of spacecraft are not required to carry fuel on board. The payload is assumed to be stationed near the astrophysical source, and the sail is subsequently unfolded and activated when the source is functional. By considering a number of astrophysical objects such as massive stars, microquasars, supernovae, pulsar wind nebulae, and active galactic nuclei, we show that terminal speeds approaching the speed of light might be realizable under idealized circumstances provided that sufficiently advanced sail materials and control techniques exist. We also investigate the constraints arising from the sail’s material properties, the voyage through the ambient source environment, and the passage through the interstellar medium. While all of these considerations pose significant challenges to spacecraft, our analysis indicates that they are not insurmountable in optimal conditions. Finally, we sketch the implications for carrying out future technosignature searches.
Can Subphotospheric Magnetic Reconnection Change the Elemental Composition in the Solar Corona?
Authors: Baker Deborah , Driel-Gesztelyi Lidia van , Brooks David H. , Démoulin Pascal , Valori Gherardo , Long David M. , Laming J. Martin , To Andy S. H. , James Alexander W. 
Published: May 2020

Abstract
Within the coronae of stars, abundances of those elements with low first ionization potential (FIP) often differ from their photospheric values. The coronae of the Sun and solar-type stars mostly show enhancements of low-FIP elements (the FIP effect) while more active stars such as M dwarfs have coronae generally characterized by the inverse-FIP effect (I-FIP). Here we observe patches of I-FIP effect solar plasma in AR 12673, a highly complex βγδ active region. We argue that the umbrae of coalescing sunspots, and more specifically strong light bridges within the umbrae, are preferential locations for observing I-FIP effect plasma. Furthermore, the magnetic complexity of the active region and major episodes of fast flux emergence also lead to repetitive and intense flares. The induced evaporation of the chromospheric plasma in flare ribbons crossing umbrae enables the observation of four localized patches of I-FIP effect plasma in the corona of AR 12673. These observations can be interpreted in the context of the ponderomotive force fractionation model which predicts that plasma with I-FIP effect composition is created by the refraction of waves coming from below the chromosphere. We propose that the waves generating the I-FIP effect plasma in solar active regions are generated by subphotospheric reconnection of coalescing flux systems. Although we only glimpse signatures of I-FIP effect fractionation produced by this interaction in patches on the Sun, on highly active M stars it may be the dominant process.
Detailed Abundances in the Galactic Center: Evidence of a Metal-rich Alpha-enhanced Stellar Population
Authors: Thorsbro B. , Ryde N. , Rich R. M. , Schultheis M. , Renaud F. , Spitoni E. , Fritz T. K. , Mastrobuono-Battisti A. , Origlia L. , Matteucci F. , Schödel R. 
Published: May 2020

Abstract
We present a detailed study of the composition of 20 M giants in the Galactic center with 15 of them confirmed to be in the nuclear star cluster. As a control sample we have also observed 7 M giants in the Milky Way disk with similar stellar parameters. All 27 stars are observed using the NIRSPEC spectrograph on the KECK II telescope in the K-band at a resolving power of R = 23,000. We report the first silicon abundance trends versus [Fe/H] for stars in the Galactic center. While finding a disk/bulge-like trend at subsolar metallicities, we find that [Si/Fe] is enhanced at supersolar metallicities. We speculate on possible enrichment scenarios to explain such a trend. However, the sample size is modest and the result needs to be confirmed by additional measurements of silicon and other α-elements. We also derive a new distribution of [Fe/H] and find the most metal-rich stars at [Fe/H] = +0.5 dex, confirming our earlier conclusions that the Galactic center hosts no stars with extreme chemical compositions.
What Makes Lyα Nebulae Glow? Mapping the Polarization of LABd05
Authors: Kim Eunchong , Yang Yujin , Zabludoff Ann , Smith Paul , Jannuzi Buell , Lee Myung Gyoon , Hwang Narae , Park Byeong-Gon 
Published: May 2020

Abstract
“Lyα nebulae” are giant (∼100 kpc), glowing gas clouds in the distant universe. The origin of their extended Lyα emission remains a mystery. Some models posit that Lyα emission is produced when the cloud is photoionized by UV emission from embedded or nearby sources, while others suggest that the Lyα photons originate from an embedded galaxy or active galactic nucleus (AGN) and are then resonantly scattered by the cloud. At least in the latter scenario, the observed Lyα emission will be polarized. To test these possibilities, we are conducting imaging polarimetric observations of seven Lyα nebulae. Here we present our results for LABd05, a cloud at z = 2.656 with an obscured, embedded AGN to the northeast of the peak of Lyα emission. We detect significant polarization. The highest polarization fractions P are ∼10%–20% at ∼20–40 kpc southeast of the Lyα peak, away from the AGN. The lowest P, including upper limits, are ∼5% and lie between the Lyα peak and AGN. In other words, the polarization map is lopsided, with P increasing from the Lyα peak to the southeast. The measured polarization angles θ are oriented northeast, roughly perpendicular to the P gradient. This unique polarization pattern suggests that (1) the spatially offset AGN is photoionizing nearby gas and (2) escaping Lyα photons are scattered by the nebula at larger radii and into our sightline, producing tangentially oriented, radially increasing polarization away from the photoionized region. Finally we conclude that the interplay between the gas density and ionization profiles produces the observed central peak in the Lyα emission. This also implies that the structure of LABd05 is more complex than assumed by current theoretical spherical or cylindrical models.
Properties of AGN Multiband Optical Variability in the HSC SSP Transient Survey
Authors: Kimura Yuki , Yamada Toru , Kokubo Mitsuru , Yasuda Naoki , Morokuma Tomoki , Nagao Tohru , Matsuoka Yoshiki 
Published: May 2020

Abstract
We study variability of active galactic nuclei (AGNs) by using the deep optical multiband photometry data obtained from the Hyper Suprime-Cam Subaru Strategic Program (HSC SSP) survey in the COSMOS field. The images analyzed here were taken with 8, 10, 13, and 15 epochs over three years in the g, r, i, and z bands, respectively. We identified 491 robust variable AGN candidates, down to i = 25 mag and with redshift up to 4.26. Ninety percent of the variability-selected AGNs are individually identified with the X-ray sources detected in the Chandra COSMOS Legacy survey. We investigate their properties in variability by using structure function analysis and find that the structure function for low-luminosity AGNs (L
bol ≲ 1045 erg s−1) shows a positive correlation with luminosity, which is the opposite trend for the luminous quasars. This trend is likely to be caused by a larger contribution of the host galaxy light for lower-luminosity AGNs. Using the model templates of galaxy spectra, we evaluate the amount of host galaxy contribution to the structure function analysis and find that dominance of the young stellar population is needed to explain the observed luminosity dependence. This suggests that low-luminosity AGNs at 0.8 ≲ z ≲ 1.8 are predominantly hosted in star-forming galaxies. The X-ray stacking analysis reveals the significant emission from the individually X-ray undetected AGNs in our variability-selected sample. The stacked samples show very large hardness ratios in their stacked X-ray spectrum, which suggests that these optically variable sources have large soft X-ray absorption by dust-free gas.