bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Impact of Helium Content on the RR Lyrae Distance Scale
Authors: Marconi M. , Bono G. , Pietrinferni A. , Braga V. F. , Castellani M. , Stellingwerf R. F. 
Published: August 2018

Abstract
We constructed new sets of He-enhanced (Y = 0.30, Y = 0.40) nonlinear, time-dependent convective hydrodynamical models of RR Lyrae (RRL) stars covering a broad range in metal abundances (Z = 0.0001–0.02). The increase in He content from the canonical value (Y = 0.245) to Y = 0.30–0.40 causes a simultaneous increase in stellar luminosity and in pulsation period. To investigate the dependence of the RRL distance scale on the He abundance, we computed new optical (RI) and near-infrared (JHK) Period–luminosity–metallicity–helium relations. Interestingly enough, the increase in He content causes a minimal change in the coefficients of both period and metallicity terms, since canonical and He-enhanced models obey similar PLZ relations. On the contrary, the classical B- and V-band mean magnitude metallicity relations and the R-band PLZ relation display a significant dependence on the He content. The He-enhanced models are, at fixed metal content, 0.2–0.5 mag brighter than canonical ones. This variation is only marginally affected by evolutionary effects. The quoted distance diagnostics once calibrated with trigonometric parallaxes (Gaia) will provide the opportunity to estimate the He content of field and cluster RRLs. Moreover, the use of either spectroscopic or photometric metal abundances will pave the way to new empirical constraints on the universality of the helium-to-metal enrichment ratio in old (t ≳ 10 Gyr) stellar tracers.
Trapping Low-mass Planets at the Inner Edge of the Protostellar Disk
Authors: Brasser R. , Matsumura S. , Muto T. , Ida S. 
Published: August 2018

Abstract
The formation of multiple close-in low-mass exoplanets is still a mystery. The challenge is to build a system wherein the outermost planet is beyond 0.2 au from the star. Here, we investigate how the prescription for type I planet migration affects the ability to trap multiple planets in a resonant chain near the inner edge of the protostellar disk. A sharp edge modeled as a hyperbolic tangent function coupled with supersonic corrections to the classical type I migration torques results in the innermost planets being pushed inside the cavity through resonant interaction with farther planets because migration is starward at slightly supersonic eccentricities. Planets below a few Earth masses are generally trapped in a resonant chain with the outermost planet near the disk edge, but long-term stability is not guaranteed. For more massive planets the migration is so fast that the eccentricity of the innermost resonant pair is excited to highly supersonic levels due to decreased damping on the innermost planet as it is pushed inside the cavity; collisions frequently occur, and the system consists of one or two intermediate-mass planets residing closer to the star than the disk’s inner edge. We found a neat pileup of resonant planets outside the disk edge only if the corotation torque does not rapidly diminish at high eccentricity. We call for detailed studies on planet migration near the disk’s inner edge, which is still uncertain, and for an improved understanding of eccentricity damping and disk torques in the supersonic regime.
Implication of the Shape of the EDGES Signal for the 21 cm Power Spectrum
Authors: Kaurov Alexander A. , Venumadhav Tejaswi , Dai Liang , Zaldarriaga Matias 
Published: August 2018

Abstract
We revisit the 21 cm power spectrum from the epoch of cosmic dawn in light of the recent Experiment to Detect the Global Epoch of reionization Signature (EDGES) detection of the 21 cm global signal at frequencies corresponding to z ∼ 20. The shape of the signal suggests that the spin temperature of neutral hydrogen was coupled to the kinetic temperature of the gas relatively rapidly (19 ≲ z ≲ 21). We therefore consider models in which the ultraviolet photons were dominantly produced in the rarest and most massive halos (M ≳ 109
M
⊙), as their abundance grows fast enough at those redshifts to account for this feature of the signal. We show that these models predict large power spectrum amplitudes during the inhomogeneous coupling, and then inhomogeneous heating by cosmic microwave background and Lyα photons due to the large shot noise associated with the rare sources. The power spectrum is enhanced by more than an order of magnitude compared to previous models that did not include the shot-noise contribution, making it a promising target for upcoming radio interferometers that aim to detect high-redshift 21 cm fluctuations.
A High Cluster Formation Efficiency in the Sagittarius B2 Complex
Authors: Ginsburg Adam , Kruijssen J. M. Diederik 
Published: August 2018

Abstract
The fraction of stars forming in compact, gravitationally bound clusters (the “cluster formation efficiency” (CFE)) is an important quantity for deriving the spatial clustering of stellar feedback and for tracing star formation using stellar clusters across the universe. Observations of clusters in nearby galaxies have revealed a strong dependence of the CFE on the local gas density, indicating that more stars form in star clusters when the star formation rate surface density is higher. Previously, it has not been possible to test this relation at very young ages and in clusters with individual stars resolved due to the universally low densities in the cluster-forming regions in the Local Group. This has even led to the suggestion that the CFE increases with distance from the Sun, which would suggest an observational bias. However, the Central Molecular Zone of the Milky Way hosts clouds with densities that are orders of magnitude higher than anywhere else in the Local Group. We report a measurement of the CFE in the highest-density region in the Galaxy, Sgr B2, based on Atacama Large Millimeter/submillimeter Array observations of high-mass young stellar objects. We find that over a third of the stars (37 ± 7%) in Sgr B2 are forming in bound clusters. This value is consistent with the predictions of environmentally dependent models for the CFE and is inconsistent with a constant CFE in the Galaxy.
Carbon cycling and food web interaction in groundwater ecosystems - key drivers and major limitations
Authors: Griebler Christian 
Published: August 2018

Groundwater ecosystems are naturally low in productivity (oligotrophic) reflected by a comparably low standing stock of biomass and slow growth and reproduction of organisms. On the other hand, aquifers are, due to their dimensions, enormous (interim) reservoirs of carbon. However, since we typically lack detailed information on carbon and energy flow through groundwater food webs, it is difficult to predict effects of climate and global change on groundwater ecosystems performance with regard to ‘sink’ or ‘source’ of carbon. Applying stable isotope analysis, high end mass spectrometry, and flow cytometry in addition to a suite of established methods in microbiology and geochemistry, we started to dissect, at selected sites, the various pools and fluxes of organic carbon in aquifers, including dissolved organic matter, particulate organic matter, and organisms. Moreover we investigated the link between carbon (organic and inorganic) and microbial growth and productivity. Last but not least, we tried to uncover food sources for groundwater fauna and the connection to microbes. The work was done in collaboration with Roland Hofmann, Katrin Hug, Marion Gallus, Lucas Fillinger, Marina Spona-Friedl, Alexander Braun, Ramona Brejcha (Institute of Groundwater Ecology at the Helmholtz Zentrum München, Germany) and Jenny Uhl, Norbert Hertkorn, and Philip Schmitt-Kopplin (Research Unit Analytical Biogeochemistry at the Helmholtz Zentrum München).
Groundwater rarely contained less than 1 mg/L DOC, however, with only a small fraction being readily biodegradable (BDOC, AOC). Unrecognized, 10-100 times the amount of organic carbon dissolved in groundwater was found to be adsorbed to the sediment matrix. Cell numbers and activities of microbes in aquifers typically ranged 1-3 orders below values from surface waters. In fact, carbon use efficiency (CUE) of groundwater bacterial communities was considerably lower than values from other oligotrophic aquatic environments, with a mean value of 5% (200 samples from 100 sites). There is ample evidence that biogeochemical processes are primarily linked to the sediment associated microbial communities that outnumber their suspended counterparts in terms of biomass and activity by 1-4 orders of magnitude. While groundwater fauna at many sites seem to live on plant derived organic matter and cannibalism, we also collected evidence for chemolithoautotrophic primary production fueling groundwater food webs.
Effectiveness of peer-mediated learning for English language learners: A meta-analysis
Authors: Cole Mikel 
Published: August 2018

This manuscript reports the findings from a series of inter-related meta-analyses of the effectiveness of peer-mediated learning for English language learners (ELLs). Peer-mediated learning is a broad term that as operationalized in this study includes cooperative learning, collaborative learning, and peer tutoring. Drawing from research on interaction in second language acquisition, as well as from work informed by Vygotskian perspectives on socially-mediated second language learning, these meta-analyses synthesize the results of experimental and quasi-experimental studies.Included studies were conducted with language learners between the ages of 3 and 18 in order to facilitate comparisons to US students in K-12 educational settings. All participants were identified as ELLs, though learners in both English as a Second Language (ESL) and English as a Foreign Language (EFL) settings were included. Similarly, learners from a variety of language backgrounds were included in order to facilitate generalizations to the linguistic diversity present in US schools, and abroad. Main effects analyses indicate that peer-mediated learning is effective at improving a number of outcome types, including: language outcomes, academic outcomes, and social outcomes. Funnel plots and Egger’s regression analyses were conducted to examine the probability of publication bias, and it appears unlikely in most analyses. Moderator analyses were also conducted, where sample sizes were sufficient, to examine what measured variables were capable of explaining heterogeneity in effect sizes between studies.
University Course Timetabling using Bayesian based Optimization Algorithm
Authors: Siame Alinaswe , Kunda Douglas 
Published: August 2018

<p>The timetabling problem has traditionally been treated as a mathematical optimization, heuristic, or human-machine interactive problem. The timetabling problem comprises hard and soft constraints. Hard constraints must be satisfied in order to generate feasible solutions. Soft constraints are sometimes referred to as preferences that can be contravened if necessary. In this research, we present is as both a mathematical and a human-machine problem that requires acceptable and controlled human input, then the algorithm gives options available without conflicting the hard constraints. In short, this research allows the human agents to address the soft-constraints as the algorithm works on the hard constraints, as well as the algorithm being able to learn the soft constraints over time. Simulation research was used to investigate the timetabling problem. Our proposed model employs the use a naïve Bayesian Algorithm, to learn preferred days and timings by lecturers and use them to resolve the soft constraints. </p>
The association between corporate social responsibility reporting and firm value for South African firms
Authors: Horn Riana , De Klerk Marna , De Villiers Charl 
Published: August 2018

Background: Corporate social responsibility (CSR) disclosure is widespread among the largest companies in South Africa due to the listing requirements of the Johannesburg Stock Exchange (JSE). These companies have also increasingly pursued external assurance of their CSR disclosures in recent years. The increased regulation of CSR disclosure and the increased rate of obtaining assurance of these disclosures motivated us to perform our study.Aim: To examine the association between CSR reporting, including both CSR disclosure and CSR assurance, and firm value of large South African companies.Setting: The JSE listing requirements place South Africa, the setting for our study, at the forefront of corporate governance and CSR reporting.Method: Tobin’s Q is used as a measure of firm value. Three measures of CSR disclosure and three of CSR assurance are used in this study. The measures are based on data collected by Klynveld Peat Marwick Goerdeler (KPMG) International on the CSR reporting practices of large South African companies. The sample period for this study coincides with the sample period covered in the KPMG surveys conducted during 2008, 2011 and 2013.Results: No significant association is found between CSR disclosure and firm value. However, a significant negative association is found between CSR assurance and firm value. Additional analysis found that the negative association between firm value and CSR assurance is more significant for companies that are not listed on the Socially Responsible Investment (SRI) index.Conclusion: The results found between CSR disclosure and firm value may suggest that firm value is unaffected by CSR disclosures. Taken together, the findings on CSR assurance and firm value and the additional analysis may suggest that in South Africa managers with negative CSR issues are more likely to obtain assurance on their CSR disclosure. The findings may be of interest to regulators when considering current and future disclosure and assurance requirements for CSR reporting in South Africa, as well as other parts of the world, shareholders when considering investment options, and managers when considering the benefit of certain CSR reporting practices.
Population exposure to droughts in China under the 1.5 °C global warming target
Authors: Chen Jie , Liu Yujie , Pan Tao , Liu Yanhua , Sun Fubao , Ge Quansheng 
Published: August 2018

Abstract. The Paris Agreement proposes a 1.5 ∘C target to limit the increase
in global mean temperature (GMT). Studying the population exposure to
droughts under this 1.5 ∘C target will be helpful in guiding new
policies that mitigate and adapt to disaster risks under climate change.
Based on simulations from the Inter-Sectoral Impact Model Intercomparison
Project (ISI-MIP), the Standardized Precipitation Evapotranspiration Index
(SPEI) was used to calculate drought frequencies in the reference period
(1986–2005) and 1.5 ∘C global warming scenario (2020–2039 in
RCP2.6). Then population exposure was evaluated by combining drought
frequency with simulated population data from shared socioeconomic pathways
(SSPs). In addition, the relative importance of climate and demographic
change and the cumulative probability of exposure change were analyzed.
Results revealed that population exposure to droughts in the east of China is
higher than that in the west; exposure in the middle and lower reaches of the
Yangtze River region is the highest, and it is lowest in the Qinghai-Tibet
region. An additional 12.89 million people will be exposed to droughts under
the 1.5 ∘C global warming scenario relative to the reference period.
Demographic change is the primary contributor to exposure (79.95 %) in
the 1.5 ∘C global warming scenario, more than climate change
(29.93 %) or the interaction effect (−9.88 %). Of the three drought
intensities – mild, moderate, and extreme – moderate droughts contribute
the most to exposure (63.59 %). Probabilities of increasing or decreasing
total drought frequency are roughly equal (49.86 % and 49.66 %,
respectively), while the frequency of extreme drought is likely to decrease
(71.83 % probability) in the 1.5 ∘C global warming scenario. The
study suggested that reaching the 1.5 ∘C target is a potential way
for mitigating the impact of climate change on both drought hazard and
population exposure.
"Internet Archive": la conservación de lo efímero
Authors: Mayagoitia Ana , González Aguilar Juan Manuel 
Published: August 2018

Lo efímero tiende a ser desechado, encontrando poca cabida en museos o archivos tradicionales. El surgimiento de archivos digitales, aunado a la aceptación de un sector del medio académico, han ayudado a modificar poco a poco la percepción que se tiene sobre los contenidos efímeros. El presente artículo tiene como objetivo el análisis de la evolución de Internet Archive, un repositorio digital especializado en la recopilación y conservación de medios efímeros. Finalmente se hace una reflexión sobre el futuro de la preservación digital y la posibilidad de crear archivos digitales similares en países de habla hispana.
INÍCIOS, DESPERTARES E CRIAÇÕES DA BELEZA FEROZ
Authors: Pascali Maria Júlia 
Published: August 2018

Consegui ter uma visão interessante das coisas que eu tenho que apresentar. Quando fui à França, estudar um mês e uma semana, no Pantheatre, Performance Vocal e Teatro Coreográfico, eu me recriei! Saí daqui muito doente, cheia de dores, sabendo que não era da minha natureza aquilo. Era por ausência de exercer a minha natureza que eu estava ficando doente. Então, eu fui para um workshop intenso, de cinco semanas. Os trabalhos iam das 09h30min às 16h30min. No primeiro dia, pensei: “Vou morrer de dor, eu não vou aguentar!”, No segundo dia, eu falei: “Eu vou morrer de dor”. E... Não tive dor nenhuma! Só melhorei, só melhorei, só melhorei.
Hidden Allusion in the Finale of Middlemarch: George Eliot and the Jewish Myth of the Lamed Vov
Authors: Adler Judith 
Published: August 2018

Abstract
This article argues that the famous concluding paragraph of George Eliot's Middlemarch contains a hitherto unrecognized cryptic allusion to a Jewish myth newly popular in her time: lamed vov, a specific “number” of “hidden” righteous persons believed to “channel” flows of divine compassion, thereby preserving and slowly improving the human world. Once recognized, this cryptic allusion has implications for the interpretation of the novel, casts new light upon the philosophical problems with which Eliot wrestled and upon her ideal of Realism, as well as upon her changing relationship to Jews and Jewish tradition. Eliot's treatment of Jewish material is commonly exclusively identified with her last works, especially Daniel Deronda. But Middlemarch marks an earlier, discreetly veiled phase of that relationship, before Eliot came publicly “out” with her philo-Semitism and determination to serve as a culture-broker. This article offers an account of Eliot's sources, of turning points in her relationship to Jews and Jewish tradition, and of the important place of Middlemarch in that development.
Atitude de consumidores brasileiros sobre o bem-estar animal
Authors: Remonato Franco Bruna Maria , Oliveira Sans Elaine Cristina de , Schnaider Maria Alice , Souza Soriano Vanessa , Forte Maiolino Molento Carla 
Published: August 2018

Os objetivos deste trabalho foram estudar e identificar as atitudes dos consumidores de produtos de origem animal com ênfase no bem-estar animal (BEA), possíveis vantagens do consumo de alimentos oriundos de melhores práticas de bem-estar e fatores que possam influenciar asdecisões de compra. Para isto, foi realizada uma pesquisa online com 402 consumidores de produtos de origem animal provenientes das cinco regiões brasileiras. Os respondentes afirmaram que o tema BEA recebe pouca importância no país, avaliando as condições dos animais de produção no Brasil como piores quando comparadas às de outras nações, e atribuíram aos produtores rurais a principal responsabilidade quanto ao assunto. Os respondentes demonstraram uma desassociaçãoentre o alimento e o animal que o originou, porém reconheceram que há influência na promoção do BEA ao adquirirem produtos diferenciados para tal atributo. Do ponto de vista dos respondentes, a disponibilidade de produtos com maior grau de bem-estar, e as informações disponíveis na rotulagem quanto à forma com que os animais são criados, constituem gargalos para a aquisição de tais produtos. O preço pode ser considerado um fator importante, visto que a maioria dos respondentes aceitaria pagar 10% (32,3%) ou 25% (24,6%) a mais em produtos produzidos com maior grau de bem-estar. Com base nos resultados, os respondentes brasileiros se importam com o BEA, porém, diversos fatores podem ser entraves para que exerçam sua preferência ética no comportamento de compra, como falta de informação para o consumidor antes e no momento da compra, baixa disponibilidade dos produtos, desassociação do produto com o animal de origem e custo elevado.
Perception of beef cattle producers in the state of Paraná regarding animal identification by hot iron branding
Authors: Müller Bruno Roberto , Souza Soriano Vanessa , De Oliveira Sans Elaine Cristina , Schnaider Maria Alice , Forte Maiolino Molento Carla 
Published: August 2018

The aim of this work was to study the perception of beef cattle producers in the state of Paraná, Brazil, about hot iron branding. Seventeen beef cattle producers answered a questionnaire about their perspective on cattle identification methods and animal welfare aspects. Results showed that there is a consensus among farmers that the identification of animals at their farms is an important practice. The majority of farmers (12/17) use hot iron branding as the main method of identification of cattle and most farmers (11/17) believe it is an efficient Method. Considering costs and applicability, 10/17 farmers believe there are other methods of identification that would be viable for utilization at their farms; ear tagging (7/17) and microchipping (3/17) were the most mentioned alternatives. Farmers affirmed believing that animals are sentient beings (16/17) and capable of experiencing pain (17/17). On a scale from 1-5, scores attributed to pain experienced capabilities of different species were high for human babies, sheep and dogs (median = 5.0). The median score attributed to the pain experienced by cattle during branding with a hot iron was 4.0, ranging from 2.0 to 5.0. In conclusion, the opinion of cattle producers in the State of Paraná, Brazil, indicates recognition of animal sentience and their ability to experience pain. Future efforts should focus on refining and developing new methods that are effective and inexpensive, motivating producers to use procedures that respect the quality of life of their animals.