bluuebunny/crossref_metadata_2025_split huggingface dataset:
CANONICAL CORRELATION ANALYSIS IN THE CASE OF MULTIVARIATE REPEATED MEASURES DATA
Authors: Krzysko Mirosław , Łukaszonek Wojciech , Wołynski Waldemar 
Published: June 2018

Abstract
In this paper, we present, in the real example, canonical variables applicable in the case of multivariate repeated measures data under the following assumptions: (1) multivariate normality for the vector of observations and (2) Kronecker product structure of the positive definite covariance matrix. These variables are especially useful when the number of observations is not large enough to estimate the covariance matrix, and thus the traditional canonical variables fail. Computational schemes for maximum likelihood estimates of required parameters are also given.
INDICATORS OF INTERNATIONAL TRADE ORIENTATION OF UKRAINE IN THE CONTEXT OF ASSESSMENT OF THE EFFECTIVENESS OF ITS EXPORT RELATIONS
Authors: Reznikova N. , Osaulenko O. , Panchenko V. 
Published: June 2018

Abstract
The approach to study the significance of trade relations between countries by analysing economic vulnerability, economic sensitivity, symmetry and asymmetry of the established economic links is proposed in the paper. This approach is adapted to an analysis of the trade dependence of Ukraine. The estimated interdependence ratios for Ukraine and its largest trade partners – the EU, the Russian Federation, post-Soviet countries, China, the USA and Brazil and India as emerging economies – are compared with the respective ratios of Ukraine’s dependence on these countries’ markets. The analysed dynamics of Ukraine’s GDP dependence on Ukraine’s trade partners shows a growing relative weight of the countries that have not had a substantial role in the foreign trade of Ukraine. The proposed approach for estimating the quality of the established trade relations is supposed to contribute to the radical transformation of Ukraine’s foreign trade.
SOME RESULTS FROM THE 2013 INTERNATIONAL YEAR OF STATISTICS
Authors: Kordos Jan 
Published: June 2018

Abstract
There are presented in this report, seven case studies of the uses of statistics in the past and present. I do not intend these examples to be exhaustive. I intend them primarily as educational examples for readers who would like to know: What is statistics good for? Also, to encourage the readers to study detailed reports from the 13 International Year of Statistics given in the notes of this report.
PRODUCT EXPONENTIAL METHOD OF IMPUTATION IN SAMPLE SURVEYS
Authors: Prasad Shakti 
Published: June 2018

Abstract
In this paper, a product exponential method of imputation has been suggested and their corresponding resultant point estimator has been proposed for estimating the population mean in sample surveys. The expression of bias and the mean square error of the suggested estimator has also been derived, up to the first order of large sample approximations. Compared with the mean imputation method, Singh and Deo (Statistical Papers (2003)) and Adapted estimator (Bahl and Tuteja (1991)), the simulation studies show that the suggested estimator is the most efficient estimator.
Investigation of estrogen activity in the raw and treated waters of riverbank infiltration using a yeast estrogen screen and chemical analysis
Authors: Plutzer Judit , Avar Péter , Keresztes Dóra , Sári Zsófia , Kiss-Szarvák Ildikó , Vargha Márta , Maász Gábor , Pirger Zsolt 
Published: June 2018

Abstract
Exposure to various endocrine disrupting chemicals (EDCs) can lead to adverse effects on reproductive physiology and behavior in both animals and humans. An adequate strategy for the prevention of environmental contamination and eliminating the effects of them must be established. Chemicals with estrogenic activity were selected, and the effectiveness of their removal during the purification processes in two drinking water treatment plants (DWTPs) using riverbank infiltrated water was determined. Thirty-five water samples in two sampling campaigns throughout different seasons were collected and screened with a yeast estrogen test; furthermore, bisphenol A (BPA), 17ß-estradiol (E2) and ethinyl-estradiol (EE2) content were measured using high-performance liquid chromatography-mass spectrometry (HPLC-MS). Our results confirm that estrogenic compounds are present in sewage effluents and raw surface river water of DWTPs. Very low estrogen activity and pg/L concentrations of BPA and E2 were detected during drinking water processing and occasionally in drinking water. Based on this study, applied riverbank filtration and water treatment procedures do not seem to be suitable for the total removal of estrogenic chemicals. Local contamination could play an important role in increasing the BPA content of the drinking water at the consumer endpoint.
Development of a combined anaerobic and aerobic membrane bioreactor for wastewater treatment and reclamation in terrestrial-based controlled ecological life support system
Authors: Cheng Zhenmin , Wei Yuansong , Gao Min , Zhang Junya , Zhang Liangchang , Ai Weidang 
Published: June 2018

Abstract
A novel wastewater treatment and reuse system (WTRS) combining an anaerobic membrane bioreactor (AnMBR) and an aerobic membrane bioreactor (MBR) with the design capacity of 115 L/d was developed for a terrestrial-based controlled ecological life support system (CELSS). Results clearly showed that the WTRS realized mineralization of organic compounds and reservation of nitrogenous nutrient, therefore converting the effluent into replenishment for the hydroponic system. Trace gas emission from the WTRS could meet requirements for the whole CELSS. Compared with physico-chemical processes, the specific consumables consumption of the WTRS was advantageous but its specific energy consumption is still in need of improvement. Results of microbial community analysis were consistent with the running state of the AnMBR and the MBR.
Efecto del uso de aguas provenientes de la producción petrolera en actividades agrícolas y pecuarias
Authors: Almansa-Manrique Édgar Fernando 
Published: June 2018

La oferta total de agua en el país es de 2,01 billones de metros cúbicos. De este volumen, la industria del petróleo tiene concesionado un total de 67,5 millones, que equivalen al 0,00336 % de la oferta total de agua en Colombia. Todo ese consumo esta formalizado mediante concesiones otorgadas por autoridades ambientales. Por otra parte, el petróleo que se extrae de la tierra sale mezclado con aguas conocidas como aguas de producción, que hacen parte de los fluidos naturales de los reservorios. En Colombia, por cada barril de petróleo se producen, en promedio, 13 barriles de agua. Las aguas de producción pueden ser tratadas y reinyectadas en la misma formación, para mantener la presión de los yacimientos y aumentar el factor de recobro; ser tratadas y vertidas a cuerpos
de aguas superficiales o al suelo, o ser reinyectadas en los yacimientos, como estrategia de disposición final. Las aguas de producción de los yacimientos de la Orinoquia tienen un contenido relativamente bajo de sales y solidos disueltos, y no poseen elementos radioactivos. Esta condición permite que, una vez que sean tratadas, puedan reusarse en actividades productivas, en predios rurales que se encuentren en el área de influencia de los proyectos petroleros. Por estas razones, la Corporación Colombiana de Investigacion Agropecuaria (Corpoica) desarrollo una serie de trabajos de investigación, dirigidos a evaluar opciones de utilización de estas aguas de producción tratadas, para la irrigación de cultivos y pastos, así como el consumo de ganado y aves de corral. Se determinó el efecto de la aplicación de aguas de producción tratadas en diferentes componentes del ecosistema y en sistemas de producción agrícola y pecuario. El estudio se desarrolló en el departamento del Meta, en el predio denominado Área Sostenible Agroenergética (ASA) (03°53’06” N y 73°35’04” O) y en el Centro de Investigacion La Libertad (04°03’32” N y 73°27’59” O), ubicados en los municipios de Acacias y Villavicencio, respectivamente. El agua de producción tratada que se utilizó provenía de los campos de Castilla y Apiay. Se seleccionó un conjunto de variables de suelos, agua, cultivos y animales, que fueron monitoreadas y analizadas entre los años 2011 y 2015. Los resultados de esta investigación indican que la utilización de estas aguas y su aplicación al suelo no presentaron efectos significativos en las propiedades físicas y químicas del suelo. Tampoco se evidenciaron consecuencias significativas en la calidad de las aguas superficiales y subterráneas, ni en la salud de animales y cultivos.
Too Busy or Well-Connected? Evidence from a Shock to Multiple Directorships
Authors: Brown Anna Bergman , Dai Jing , Zur Emanuel 
Published: June 2018

ABSTRACT
Prior literature documents that multiple directorships are negatively associated with operating performance due to overly busy directors; however, multiple directorships may also increase firm value because directors gain access to valuable connections, resources, and information through their multiple appointments. This paper examines M&A that terminate target firms' entire boards as a negative shock to both board busyness and connections at other firms, as a complement to Hauser (2018). We document that firms experiencing a decrease in multiple directorships due to M&A exhibit improved operating performance, monitoring, and strategic advising, on average. Firms with the smallest decrease in board connections experience the greatest improvement in operating performance and advising, while firms with the greatest decrease in board connections experience null or negative effects on operating performance and advising. Our findings provide new evidence of the costs and benefits of multiple directorships based on board busyness and connections.
Numerical Investigation for the Design of a Central Recuperator with Hybrid Air Preheating*
Authors: Scheck F. , Schwotzer C. , Pfeifer H. , Bender W. 
Published: June 2018

Abstract
Industrial furnaces, especially in steel industry but also in non-ferrous, ceramic or chemical industry, are often fired with fossil fuels like natural gas, oil or coke. Considering the transition to green energy, it is necessary to enable the use of renewable energies like wind and solar energy in fossil-fueled furnaces. Resulting from this motivation, a hybrid recuperator for combustion air preheating with off-gas heat and electric energy is being developed in a public research and development project. The hybrid recuperator consists of a conventional tube bundle module and an electric heating module. The design of the prototype is based on numerical investigations to determine pressure loss, increase in temperature and heat transfer. This article introduces the concept of the new hybrid recuperator and initial results of numerical investigations for a small-scale hybrid recuperator geometry.
Postoperative re-irradiation using stereotactic body radiotherapy for metastatic epidural spinal cord compression
Authors: Ito Kei , Nihei Keiji , Shimizuguchi Takuya , Ogawa Hiroaki , Furuya Tomohisa , Sugita Shurei , Hozumi Takahiro , Keisuke Sasai  , Karasawa Katsuyuki 
Published: June 2018

OBJECTIVEThis study aimed to clarify the outcomes of postoperative re-irradiation using stereotactic body radiotherapy (SBRT) for metastatic epidural spinal cord compression (MESCC) in the authors’ institution and to identify factors correlated with local control.METHODSCases in which patients with previously irradiated MESCC underwent decompression surgery followed by spine SBRT as re-irradiation between April 2013 and May 2017 were retrospectively reviewed. The surgical procedures were mainly performed by the posterior approach and included decompression and fixation. The prescribed dose for spine SBRT was 24 Gy in 2 fractions. The primary outcome was local control, which was defined as elimination, shrinkage, or no change of the tumor on CT or MRI obtained approximately every 3 months after SBRT. In addition, various patient-, treatment-, and tumor-specific factors were evaluated to determine their predictive value for local control.RESULTSTwenty-eight cases were identified in the authors’ institutional databases as meeting the inclusion criteria. The histology of the primary disease was thyroid cancer in 7 cases, lung cancer in 6, renal cancer in 3, colorectal cancer in 3, and other cancers in 9. The most common previous radiation dose was 30 Gy in 10 fractions (15 cases). The mean interval since the most recent irradiation was 16 months (range 5–132 months). The median duration of follow-up after SBRT was 13 months (range 4–38 months). The 1-year local control rate was 70%. In the analysis of factors related to local control, Bilsky grade, number of vertebral levels in the treatment target, the interval between the latest radiotherapy and SBRT, recursive partitioning analysis (RPA), the prognostic index for spinal metastases (PRISM), and the revised Tokuhashi score were not significantly correlated with local control. The favorable group classified by the Rades prognostic score achieved a significantly higher 1-year local control rate than the unfavorable group (1-year local control rate: 100% vs 33%; p < 0.01). Radiation-induced myelopathy and vertebral compression fracture were observed in 1 and 3 patients, respectively. No other grade 3 or greater toxicities were encountered.CONCLUSIONSThe results indicate that spine SBRT as postoperative re-irradiation was effective, and it was especially useful for patients classified as having a good survival prognosis according to the Rades score.
Optimisation of Microwave Pretreatment for Biogas Enhancement through Anaerobic Digestion of Microalgal Biomass
Authors: Feng RuiZhe , Zaidi Asad A. , Zhang Kun , Shi Yue 
Published: June 2018

In this study, optimization of microwave (MW) pretreatment conditions for anaerobic digestion of green microalgae (Enteromorpha) is carried out by using response surface methodology (RSM). MW power, pretreatment time and liquid-solid ratio were selected as independent variables for optimization. The optimum conditions were achieved at MW power, pretreatment time and liquid-solid ratio of 656.92 W, 5.10 min and 33.63:1, respectively. From these optimum conditions, it was found that MW pretreatment power of about 600 W had better effect. An anaerobic digestion was carried out batch-wise with working volume, operating temperature and mixing rate as 250 ml, 37 °C and 150 rpm, respectively. Optimum conditions provide highest amount of COD and reducing sugar increase of 10,420 mg/L and 0.77-0.79 g/L respectively. The increase in COD and reducing sugar showed that the pretreatment has improved anaerobic digestion of microalgae. The peak biogas production amount of MW pretreated 20:1, 6 min group reached 244 mL whereas the control group only reached 188 mL in total.
A Magnetohydrodynamic Simulation of Magnetic Null-point Reconnections in NOAA AR 12192, Initiated with an Extrapolated Non-force-free Field
Authors: Prasad A. , Bhattacharyya R. , Hu Qiang , Kumar Sanjay , Nayak Sushree S. 
Published: June 2018

Abstract
The magnetohydrodynamics of the solar corona is simulated numerically. The simulation is initialized with an extrapolated non-force-free magnetic field using the vector magnetogram of the active region NOAA 12192, which was obtained from the solar photosphere. Particularly, we focus on the magnetic reconnections (MRs) occurring close to a magnetic null point that resulted in the appearance of circular chromospheric flare ribbons on 2014 October 24 around 21:21 UT, after the peak of an X3.1 flare. The extrapolated field lines show the presence of the three-dimensional (3D) null near one of the polarity-inversion lines—where the flare was observed. In the subsequent numerical simulation, we find MRs occurring near the null point, where the magnetic field lines from the fan plane of the 3D null form a X-type configuration with underlying arcade field lines. The footpoints of the dome-shaped field lines, inherent to the 3D null, show high gradients of the squashing factor. We find slipping reconnections at these quasi-separatrix layers, which are co-located with the post-flare circular brightening observed at chromospheric heights. This demonstrates the viability of the initial non-force-free field, along with the dynamics it initiates. Moreover, the initial field and its simulated evolution are found to be devoid of any flux rope, which is congruent with the confined nature of the flare.
A High-resolution Study of Presupernova Core Structure
Authors: Sukhbold Tuguldur , Woosley S. E. , Heger Alexander 
Published: June 2018

Abstract
The density structure surrounding the iron core of a massive star when it dies is known to have a major effect on whether or not the star explodes. Here we repeat previous surveys of presupernova evolution with some important corrections to code physics and four to 10 times better mass resolution in each star. The number of presupernova masses considered is also much larger. Over 4000 models are calculated in the range from 12 to 60 M
⊙ with varying mass loss rates. The core structure is not greatly affected by the increased spatial resolution. The qualitative patterns of compactness measures and their extrema are the same, but with the increased number of models, the scatter seen in previous studies is replaced by several localized branches. More physics-based analyses by Ertl et al. and Müller et al. show these branches with less scatter than the single-parameter characterization of O’Connor & Ott. These branches are particularly apparent for stars in the mass ranges 14–19 and 22–24 M
⊙. The multivalued solutions are a consequence of interference between several carbon- and oxygen-burning shells during the late stages of evolution. For a relevant range of masses, whether a star explodes or not may reflect the small, almost random differences in its late evolution more than its initial mass. The large number of models allows statistically meaningful statements about the radius, luminosity, and effective temperatures of presupernova stars, their core structures, and their remnant mass distributions.
The Lives of Stars: Insights from the TGAS–RAVE–LAMOST Data Set
Authors: Vickers John J. , Smith Martin C. 
Published: June 2018

Abstract
In this paper, we investigate how the chemical and kinematic properties of stars vary as a function of age. Using data from a variety of photometric, astrometric, and spectroscopic surveys, we calculate the ages, phase space information, and orbits for ∼125,000 stars covering a wide range of stellar parameters. We find indications that the inner regions of the disk reached high levels of enrichment early, while the outer regions were more substantially enriched in intermediate and recent epochs. We consider these enrichment histories through comparison of the ages of stars, their metallicities, and kinematic properties, such as their angular momentum in the solar neighborhood (which is a proxy for orbital radius). We calculate rates at which the velocity dispersions evolve, investigate the Oort constants for populations of different ages (finding a slightly negative ∂V
C/∂R and ∂V

R
/∂R for all ages, which is most negative for the oldest stars), as well as examine the behavior of the deviation angle of the velocity vertex as a function of age (which we find to fall from ∼15° for the 2 Gyr old population to ∼6° at around 6.5 Gyr of age, after which it remains unchanged). We find evidence for stellar churning, and find that the churned stars have a slightly younger age distribution than the rest of the data.
A Stringent Limit on the Mass Production Rate of r-process Elements in the Milky Way
Authors: Macias Phillip , Ramirez-Ruiz Enrico 
Published: June 2018

Abstract
We analyze data from several studies of metal-poor stars in the Milky Way, focusing individually on the main r-process elements (Eu) as well as the lighter neutron-capture element Sr, at the neutron-magic peak N = 50. Because these elements were injected in an explosion, we calculate the mass swept up when the blast wave first becomes radiative, yielding a lower limit for the dilution of such elements and hence a lower limit on the ejecta mass that is incorporated into the next generation of stars. Our study demonstrates that in order to explain the largest enhancements in [Eu/Fe] observed in stars at low [Fe/H] metallicities, individual r-process production events must synthesize a minimum of roughly 10−3
M
⊙ of r-process material. This provides a critical constraint on galactic chemical evolution models. We also show independently that if the site of Mg production is the same as that of Eu, individual injection events must synthesize up to ∼10−3
M
⊙ of r-process material. On the other hand, demanding that Sr traces Mg production results in r-process masses per event of ∼10−5
M
⊙ . This suggests that the astrophysical sites responsible for the genesis of the main r-process elements need to operate at a drastically reduced rate when compared to standard core-collapse supernovae.
C. Licinius Adin: uno de los últimos iberos
Authors: Simón Cornago Ignacio 
Published: June 2018

Résumé Un cachet, sur un dolium de Can Pedrerol, porte le texte C. LIC. ADIN. Il s’agit d’un individu, avec un cognomen ibérique, appartenant à la gens Licinia , une des grandes familles et parmi les plus connues de Barcino qui se consacrait à l’exploitation vinicole. La présence d’un cognomen ibérique dans l’onomastique de cet individu est à souligner, car rares sont les mentions d’un nom ibérique dans l’épigraphie latine.
Tradition in the Making: New Approaches on Panegyricus Latinus , XII(9)
Authors: Maranesi Alessandro 
Published: June 2018

Résumé Le propos de cet article est de montrer comment, sous le règne de Constantin le Grand, la reconstruction de la mémoire reposait sur des bases locales. On se focalisera, en particulier, sur Panegyricus Latinus , XII(9) [= IX(12) CUF] pour démontrer qu’il résultait d’une perspective gauloise païenne. L’utilisation du passé récent que fait le rhétoricien dans son récit de la bataille du pont Milvius prouve que, dans cette période de transition, la reconstruction de la victoire de Constantin était la résultante de divers agents politiques.
Problématique des investisseurs. Finance et droit des sûretés
Authors: Gentil Étienne 
Published: June 2018

Le droit français appréhende mal la réalité des situations dans lesquelles les financements d’une certaine taille bénéficient de sûretés. On déplore le manque de flexibilité qui s’applique à des intervenants de marché qui devraient être plus libres d’organiser leurs relations comme ils l’entendent. L’efficience économique du droit des sûretés français est entachée par son caractère éclaté qui notamment organise imparfaitement l’information des tiers. On devrait envisager une uniformisation des règles de publicité, voire la création d’une sûreté mobilière unique. Les procédures d’insolvabilité méconnaissent les droits théoriquement donnés aux détenteurs des sûretés. Le système américain apporte sur certains aspects une réponse radicalement différente au même objectif de préservation de l’entreprise. Les prêteurs seront plus enclins à apporter leurs concours financiers dans un système juridique qui donnera effet à leurs accords. Les facteurs d’incertitude liés aux mécanismes de protection de crédit augmentent les coûts prudentiels des établissements de crédits et donc le coût du crédit. Les réformes du droit français des sûretés et des procédures françaises d’insolvabilité à venir devront en tenir compte. Classification JEL : G23, G28, K22.