bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compromiso Estudiantil en el Contexto Universitario Colombiano y Desempeño Académico
Authors: Pineda-Báez Clelia , Bermúdez José-Javier , Rubiano-Bello Ángela , Pava-García Natalia , Suárez-García Rodrigo , Cruz-Becerra Fabián 
Published: January 2015

A pesar de la ampliación de la cobertura en	la educación superior latinoamericana, persisten graves	problemas de deserción que llevan a cuestionar el papel de	las experiencias educativas en el fomento del compromiso	académico de los estudiantes. Esta investigación se realizó	en Colombia y buscó determinar la relación que existe entre	el compromiso estudiantil y el desempeño académico de un	grupo de universitarios colombianos. El estudio transversal	y correlacional empleó la versión en español de la encuesta	National Survey of Student Engagement (NSSE) que mide el nivel de participación de los estudiantes	en cinco dimensiones: reto académico, aprendizaje activo y	colaborativo, interacción con docentes y personal	administrativo, experiencias educativas enriquecedoras y	apoyo institucional. Los hallazgos de 1906 estudiantes de 7	universidades señalan que existen correlaciones	estadísticamente significativas, aunque débiles, entre los	índices del compromiso estudiantil y el promedio académico,	y conducen a reflexionar sobre aspectos claves para el	fortalecimiento de las experiencias educativas que se	ofrecen al universitario.
Literatura y sociedad. Algunos ejemplos de la presencia de Jaime I en la Región de Murcia, a través de diversos contextos escritos. Siglos XIX y XX
Authors: Doménech Villa Ramón 
Published: January 2015

Cada lugar se caracteriza por tener su héroe particular. Sería muy difícil encontrar dos héroes compartidos en diferentes espacios físicos, mucho más si estos se encuentran limitando entre sí. En la actualidad podría ser comparable a las rivalidades existentes en ciertas competiciones deportivas, incluso podríamos plantearnos la existencia de ciertos paralelismos entre estos y aquellas situaciones bélicas producidas en siglos anteriores. La Región de Murcia, Andalucía y el País Valencià, compitieron en un particular duelo de protagonismo monárquico, con claros parentescos familiares, durante el siglo XIII. Ante el predominio de uno u otro monarca, y sin contar con su protagonismo destacado podríamos hacernos multitud de preguntas: ¿Desaparecieron todas las referencias al rey Jaime I, dentro del marco de la sociedad murciana, una vez pasados los siglos con otro rey como protagonista? ¿Sería posible encontrar referencias a él, en contextos relacionados sociales de la Región de Murcia? ¿Jugó la literatura de la época algún papel en este sentido? ¿El ciudadano de la Región podía crear un contexto no formal de aprendizaje histórico?
Evidence for generation of unstable suprathermal electron population in the auroral F region
Authors: Akbari H. , Semeter J. L. , Hirsch M. A. , Guio P. , Nicolls M. J. 
Published: January 2015

AbstractAnomalous incoherent scatter radar (ISR) spectra confined to narrow altitude ranges near the F region peak and correlated with dynamic auroral precipitation have previously been identified and explained in terms of the cavitating beam‐driven Langmuir turbulence. In this work we used a one‐dimensional Zakharov simulation to constrain the range of physical mechanisms underlying these observational features. We find that although Langmuir wave collapse and caviton formation generated by electron beams with energies of 1 keV can give rise to similar radar echoes, the predicted spectral features and intensities of such echoes are inconsistent with experimental data acquired by various ISRs. Our results suggest that the free energy for the turbulence must be provided by unstable low‐energy (5 − 20 eV) electron populations and that such populations must be produced locally in the F region ionosphere.
Investigation of the atmospheric boundary layer depth variability and its impact on the 222Rn concentration at a rural site in France
Authors: Pal S. , Lopez M. , Schmidt M. , Ramonet M. , Gibert F. , Xueref‐Remy I. , Ciais P. 
Published: January 2015

AbstractContinuous monitoring of the atmospheric boundary layer (ABL) depth (zi) is important for investigations of trace gases with near‐surface sources. The aim of this study is to examine the temporal variability of zi on both diurnal and seasonal time scales over a full year (2011) and relate these changes to the atmospheric 222Rn concentrations (CRn) measured near the top of a 200 m tower at a rural site (Trainou) in France. Continuous zi estimates were made using a combination of lidar and hourly four‐height carbon dioxide (CO2) profile measurements. Over the diurnal cycle, the 180 m CRn reached a maximum in the late morning as the growing ABL passed through the inlet height (180 m) transporting upward high CRn air from the nocturnal boundary layer. During late afternoon, a minimum in the CRn occurred mainly due to ABL‐mixing. We argue that ABL dilution occurs in two stages: first, during the rapid morning growth into the residual layer, and second, during afternoon with the free atmosphere when zi has reached its quasi‐stationary height (around 750 m in winter or 1700 m in summer). An anticorrelation (R2 of −0.49) was found while performing a linear regression analysis between the daily zi growth rates and the corresponding changes in the CRn illustrating the ABL‐dilution effect. We also analyzed the numerical proportions of the time within a season when zi remained lower than the inlet height and found a clear seasonal variability for the nighttime measurements with higher number of cases with shallow zi (<200 m) in winter (67.3%) than in summer (33.9%) and spring (54.5%). Thus, this pilot study helps delineate the impact of zi on CRn at the site mainly for different regimes of ABL, in particular, during the times when the zi is above the measurement height. It is suggested that when the zi is well below the inlet height, measurements are most possibly indicative of the residual layer 222Rn, an important issue that should be considered in the mass budget approach.
Formation of iron‐rich shelled structures by microbial communities
Authors: Fernández‐Remolar David C. , Santamaría Joan , Amils Ricardo , Parro Victor , Gómez‐Ortíz D. , Izawa Matthew R. M. , Banerjee Neil R. , Pérez Rodríguez Raúl , Rodríguez Nuria , López‐Martínez Nieves 
Published: January 2015

AbstractIn this paper, we describe the discovery and characterization of shelled structures that occur inside galleries of Pyrenees mines. The structures are formed by the mineralization of iron and zinc oxides, dominantly franklinite (ZnFe2O4) and poorly ordered goethite (α‐FeO(OH)). Subsurface oxidation and hydration of polymetallic sulfide orebodies produce solutions rich in dissolved metal cations including Fe2+/3+ and Zn2+. The microbially precipitated shell‐like structure grows by lateral or vertical stacking of thin laminae of iron oxide particles which are accreted mostly by fungal filaments. The resulting structures are composed of randomly oriented aggregates of needle‐like, uniform‐sized crystals, suggesting some biological control in the structure formation. Such structures are formed by the integration of two separated shells, following a complex process driven likely by different strategies of fungal microorganisms that produced the complex macrostructure.
Strukturelle Charakterisierung von O‐ und C‐glycosylierenden Varianten der Landomycin‐Glycosyltransferase LanGT2
Authors: Tam Heng Keat , Härle Johannes , Gerhardt Stefan , Rohr Jürgen , Wang Guojun , Thorson Jon S. , Bigot Aurélien , Lutterbeck Monika , Seiche Wolfgang , Breit Bernhard , Bechthold Andreas , Einsle Oliver 
Published: January 2015

AbstractStrukturen der O‐Glycosyltransferase LanGT2 und der generierten C‐Glycosyltransferase LanGT2S8Ac zeigen, dass der Austausch eines kurzen Peptidfragments die Funktionalität eines Enzyms deutlich verändern kann. Eine synthetische TDP‐Carbaolivose wurde mit den Enzymen kokristallisiert. Es zeigte sich, dass die Bindung des Carbazuckers zu einer Konformationsänderung des Enzyms führt, die dann eine Bindestelle für ein Aglykonsubstrat erzeugt. Obwohl eine Bindung des Aglykons nicht experimentell nachgewiesen wurde, deuten Docking‐Studien auf unterschiedliche Bindungsmodi im Fall von O‐ bzw. C‐Glycosylierung hin.
Design and in vivo assessment of polyester copolymers based on trimethylene carbonate and ε‐caprolactone
Authors: Zhang Chong , Liu Danhua , Zhang Xiaowei , Wang Ping , Zhen Zhu , Li Jianxin , Yi Dongxu , Jin Ying , Yang Dan 
Published: January 2015

ABSTRACTPoly(trimethylene carbonate‐co‐caprolactone) (PTCL) copolymers with various trimethylene carbonate ratios were synthesized by ring‐opening polymerization and were used to prepare implants for an in vivo experiment. Medical silicone rubber was used as the control. Implants were prepared by compression molding with a laboratory instrument. The properties of these copolymer implants were investigated. PTCL implants and silicone rubbers were implanted subcutaneously in the dorsal region of New Zealand white rabbits. The assessment was performed 1, 2, 3, 4, 5, 6, 7, and 8 months postoperatively by the determination of the weight loss, water uptake, thermal behavior, molecular weight of the explanted implants, and histological examination. During the 8‐month implantation, the value of maximum weight loss was found to be 25%. A continuous decrease in the molecular weight occurred. No remarkable tissue reactions were observed during degradation, and foreign‐body reactions were similar to those of silicone rubbers, which are commercially available materials. In this study, we aimed to indicate the likely clinical behavior but good biodegradable properties of PTCL copolymers compared to those of silicone rubber. This may open a new avenue of application for them in the drug industry. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41815.
Selective Oxidation of Alkyl‐Substituted Polyaromatics Using Ruthenium‐Ion‐Catalyzed Oxidation
Authors: Nowicka Ewa , Sankar Meenakshisundaram , Jenkins Robert L. , Knight David W. , Willock David J. , Hutchings Graham J. , Francisco Manuel , Taylor Stuart H. 
Published: January 2015

AbstractRuthenium‐ion‐catalyzed oxidation of a range of alkylated polyaromatics has been studied. 2‐Ethylnaphthalene was used as a model substrate, and oxidation can be performed in either a conventional biphasic or in a monophasic solvent system. In either case the reaction rates and product selectivity are identical. The reaction products indicate that the aromatic ring system is oxidized in preference to the alkyl chain. This analysis is possible due to the development of a quantitative NMR protocol to determine the relative amounts of aliphatic and aromatic protons. From a systematic set of substrates we show that as the length of the alkyl chain substituent on a polyaromatic increases, the proportion of products in which the chain remains attached to the aromatic system increases. Larger polyaromatic systems, based on pyrene and phenanthrene, show greater reactivity than those with fewer aromatic rings, and the alkyl chains are more stable to oxidation.
Application of endocrine disruptor screening program fish short-term reproduction assay: Reproduction and endocrine function in fathead minnow (Pimephales promelas) and killifish (Fundulus heteroclitus) exposed to Bermuda pond sediment
Authors: Fort Douglas J. , Mathis Michael , Fort Chelsea E. , Fort Hayley M. , Bacon Jamie P. 
Published: January 2015

Abstract

A modified tier 1 Endocrine Disruptor Screening Program (EDSP) 21-d fish short-term reproduction assay (FSTRA) was used to evaluate the effects of sediment exposure from freshwater and brackish ponds in Bermuda on reproductive fecundity and endocrine function in fathead minnow (Pimephales promelas) and killifish (Fundulus heteroclitus). Reproductively active male and female fish were exposed to control sediment and sediment from 2 freshwater ponds (fathead minnow) and 2 marine ponds (killifish) contaminated with polyaromatic hydrocarbons and metals via flow-through exposure for 21 d. Reproductive fecundity was monitored daily. At termination, the status of the reproductive endocrine system was assessed by the gonadosomatic index, gonadal histology, plasma steroids (estrogen [E2], testosterone [T], and 11-ketotestosterone [11-KT]), steroidogenic enzymes (aromatase and combined 3β/17β -hydroxysteroid dehydrogenase [3β/17β-HSD]), and plasma vitellogenin (VTG). Decreased reproductive fecundity, lower male body weight, and altered endocrinological measures of reproductive status were observed in both species. Higher plasma T levels in female minnows and 11-KT levels in both male and female minnows and female killifish exposed to freshwater and brackish sediments, respectively. Decreased female E2 and VTG levels and gonadal cytochrome P19 (aromatase) activity were also found in sediment exposed females from both species. No effect on female 3β/17β-HSD activity was found in either species. The FSTRA provided a robust model capable of modification to evaluate reproductive effects of sediment exposure in fish. Environ Toxicol Chem 2015;34:1283–1295. © 2015 SETAC
The physicochemical properties of microwave‐assisted encapsulated anthocyanins from Ipomoea batatas as affected by different wall materials
Authors: Mohd Nawi Norazlina , Muhamad Ida Idayu , Mohd Marsin Aishah 
Published: January 2015

AbstractThis study focuses on the impact of different wall materials on the physicochemical properties of microwave‐assisted encapsulated anthocyanins from Ipomoea batatas. Using the powder characterization technique, purple sweet potato anthocyanin (PSPAs) powders were analysed for moisture content, water activity, dissolution time, hygroscopicity, color and morphology. PSPAs were produced using different wall materials: maltodextrin (MD), gum arabic (GA) and a combination of gum arabic and maltodextrin (GA + MD) at a 1:1 ratio. Each of the wall materials was homogenized to the core material at a core/wall material ratio of 5 and were microencapsulated by microwave‐assisted drying at 1100 W. Results indicated that encapsulated powder with the GA and MD combination presented better quality of powder with the lowest value of moisture content and water activity. With respect to morphology, the microcapsule encapsulated with GA + MD showed several dents in coating surrounding its core material, whereas other encapsulated powders showed small or slight dents entrapped onto the bioactive compound. Colorimetric analysis showed changes in values of L, a*, b*, hue and chroma in the reconstituted powder compared to the initial powder.
Oxygenic photosynthesis‐specific subunits of cyanobacterial NADPH dehydrogenases
Authors: Ma Weimin , Ogawa Teruo 
Published: January 2015

AbstractCyanobacterial NADPH dehydrogenase (NDH‐1) or NDH‐1‐like complex is localized in the thylakoid membrane and participates in a variety of bioenergetic reactions, including respiration, cyclic electron transport around photosystem I and CO2 uptake. Over the past decade, a significant achievement has been made in identifying seven oxygenic photosynthesis‐specific (OPS) subunits of NDH‐1 enzyme, NdhL to NdhQ and NdhS, in several cyanobacterial strains. Six of them are also found in higher plants but not in nonphototrophs. This indicates an exclusive existence of these OPS Ndh subunits in oxygenic photosynthetic organisms and suggested certain role of cyanobacterial and chloroplastic NDH‐1 in photosynthetic reactions. In this review, we describe these seven OPS subunits of cyanobacterial NDH‐1, focusing on their identification, localization, function, and evolution from cyanobacteria to higher plants. A crucial role of these OPS subunits on the function of cyanobacterial NDH‐1 is proposed. © 2015 IUBMB Life, 67(1):3–8, 2015
Effects of International Student Counselors' Broaching Statements About Cultural and Language Differences on Participants' Perceptions of the Counselors
Authors: Choi Gahee , Mallinckrodt Brent , Richardson John D. 
Published: January 2015

Undergraduates (N = 135) evaluated 1 of 4 simulated 1st counseling sessions. Two international counselors (Canadian and Korean) alternated between making or not making broaching statements about their language and cultural differences. Significant main effects for counselor nationality and interaction effects between counselor nationality and broaching were found. Participants perceived the Canadian counselor more positively and the Korean counselor less positively in the broaching condition. Participants' cognitive flexibility was a significant covariate of their perceptions.Un grupo de estudiantes universitarios (N = 135) evaluó 1 de 4 sesiones iniciales de consejería simuladas. Dos consejeros internacionales (canadiense y coreano) alternaron entre hacer comentarios o no para abordar las diferencias entre sus idiomas y culturas. Se encontraron efectos principales significativos en relación a la nacionalidad del consejero y una interacción entre la nacionalidad y el abordamiento. Los participantes percibieron al consejero canadiense de forma más positiva y al consejero coreano de forma menos positiva en la situación de abordamiento. La flexibilidad cognitiva de los participantes fue una covariable significativa en su percepción.
Constructing Pandiagonal Latin Squares from Linear Cellular Automaton on Elementary Abelian Groups
Authors: Dabbaghian Vahid , Wu Tiankuang 
Published: January 2015

AbstractThe constructed pandiagonal Latin squares by Hedayat's method are cyclic. During the last decades several authors described methods for constructing pandiagonal Latin squares that are semi‐cyclic. In this article, we have applied linear cellular automaton on elements of permutation elementary abelian p‐groups, which are ordered by the lexicographic ordering, and we proposed an algorithm for constructing noncyclic pandiagonal Latin squares of order , for prime .
Imaging dose in breast radiotherapy: does breast size affect the dose to the organs at risk and the risk of secondary cancer to the contralateral breast?
Authors: Batumalai Vikneswary , Quinn Alexandra , Jameson Michael , Delaney Geoff , Holloway Lois 
Published: January 2015

AbstractIntroductionCorrect target positioning is crucial for accurate dose delivery in breast radiotherapy resulting in utilisation of daily imaging. However, the radiation dose from daily imaging is associated with increased probability of secondary induced cancer. The aim of this study was to quantify doses associated with three imaging modalities and investigate the correlation of dose and varying breast size in breast radiotherapy.MethodsPlanning computed tomography (CT) data sets of 30 breast cancer patients were utilised to simulate the dose received by various organs from a megavoltage computed tomography (MV‐CT), megavoltage electronic portal image (MV‐EPI) and megavoltage cone‐beam computed tomography (MV‐CBCT). The mean dose to organs adjacent to the target volume (contralateral breast, lungs, spinal cord and heart) were analysed. Pearson correlation analysis was performed to determine the relationship between imaging dose and primary breast volume and the lifetime attributable risk (LAR) of induced secondary cancer was calculated for the contralateral breast.ResultsThe highest contralateral breast mean dose was from the MV‐CBCT (1.79 Gy), followed by MV‐EPI (0.22 Gy) and MV‐CT (0.11 Gy). A similar trend was found for all organs at risk (OAR) analysed. The primary breast volume inversely correlated with the contralateral breast dose for all three imaging modalities. As the primary breast volume increases, the likelihood of a patient developing a radiation‐induced secondary cancer to the contralateral breast decreases. MV‐CBCT showed a stronger relationship between breast size and LAR of developing a radiation‐induced contralateral breast cancer in comparison with the MV‐CT and MV‐EPI.ConclusionsFor breast patients, imaging dose to OAR depends on imaging modality and treated breast size. When considering the use of imaging during breast radiotherapy, the patient's breast size and contralateral breast dose should be taken into account.
Above 16% efficient sequentially grown Cu(In,Ga)(Se,S)2‐based solar cells with atomic layer deposited Zn(O,S) buffers
Authors: Merdes Saoussen , Ziem Florian , Lavrenko Tetiana , Walter Thomas , Lauermann Iver , Klingsporn Max , Schmidt Sebastian , Hergert Frank , Schlatmann Rutger 
Published: January 2015

AbstractWe report the development of Cd‐free buffers by atomic layer deposition for chalcopyrite‐based solar cells. Zn(O,S) buffer layers were prepared by atomic layer deposition on sequentially grown Cu(In,Ga)(Se,S)2 absorbers from Bosch Solar CISTech GmbH. An externally certified efficiency of 16.1% together with an open circuit voltage of 612 mV were achieved on laboratory scale devices. Stability tests show that the behavior of the ALD‐Zn(O,S)‐buffered devices can be characterized as stable only showing a minor drift of the open circuit voltage and the fill factor. Copyright © 2015 John Wiley & Sons, Ltd.
Abnormal shape of the cavum septi pellucidi: an indirect sign of partial agenesis of the corpus callosum
Authors: Shen O. , Gelot A. B. , Moutard M. L. , Jouannic J. M. , Sela H. Y. , Garel C. 
Published: January 2015

AbstractObjectiveTo
describe and assess the presence of a new indirect sign of partial agenesis of the corpus callosum (pACC): an abnormally shaped cavum septi pellucidi (CSP).MethodsWe analyzed retrospectively images from all 71 cases of pACC seen at two referral centers between September 2006 and April 2014. Abnormally shaped CSP was diagnosed when its lateral dimension was greater than its anteroposterior dimension in the axial transthalamic plane, and the incidence of this sign was assessed. We also examined the following variables: gestational age at referral, indication for referral, which (if any) of the four corpus callosal segments were abnormal, presence of other, previously established, indirect signs of callosal agenesis (ACC) and presence of additional cerebral or extracerebral anomalies.ResultsIn 56 of the 71 (79%) cases, the CSP was measurable; it was abnormally shaped in 19 (34%) of these cases, 15 (79%) of which had no other indirect signs of pACC. Of 23 cases with isolated pACC and no other indirect signs, 12 (52%) had an abnormally shaped CSP.ConclusionsIn a significant proportion of cases of pACC detected prenatally, the shape of the CSP is abnormal. This should be considered an additional indirect sign of pACC, and is frequently the only clue to the diagnosis. When observing this sign in a screening context, pACC should be considered, and an attempt to visualize the corpus callosum directly in the midsagittal plane is suggested. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.