bluuebunny/crossref_metadata_2025_split huggingface dataset:
Disminución del rendimiento académico con el Plan Bolonia respecto al plan anterior en España
Authors: López Rodríguez María Isabel , Palací López Daniel Gonzalo , Palací López Jesús 
Published: May 2016

La incorporación del Sistema Europeo de Transferencia de Créditos (ECTS) verá sus frutos en breve con la salida al mercado laboral de los primeros egresados. En este estudio se realiza una primera valoración de los resultados obtenidos, analizando si el plan de estudios (grado o licenciatura) y el uso de las nuevas metodologías docentes han marcado diferencias significativas en el rendimiento académico. Los resultados indican que éste es mayor en los licenciados y para los alumnos que se han beneficiado de una nueva herramienta pedagógica. Se han considerado los datos de dos promociones de doble licenciatura y doble grado. Descartadas, como causas, inputs potencialmente importantes como nivel preuniversitario y opción de bachillerato se plantea, como causa de la disminución del rendimiento, la implantación de los grados con una inversión prácticamente nula, lo que habría supuesto que el alumnado carezca de la disminución de presencialidad requerida para la correcta autogestión académica
O dinheiro e a comida na metrópole: as escolhas alimentares entre beneficiárias do Programa Bolsa Família no Rio de Janeiro
Authors: Passos Lima Maria Raquel , Oliveira Silva Denise , Dos Anjos Pontes Liliane 
Published: May 2016

Este artigo aborda as escolhas alimentares como objeto do Programa Bolsa Família, política pública brasileira de transferência condicionada de renda e combate à fome. O objetivo é pensar as relações entre a alimentação e a renda recebida por beneficiárias do PBF residentes no Rio de Janeiro. Argumentamos que a reflexão sobre a escolha alimentar deve considerar a “economia doméstica”, que inclui modalidades de arranjosfamiliares e estratégias de obtenção de renda por parte dos sujeitos contemplados. Sua análise revela a imersão do dinheiro do PBF no contexto sociocultural das beneficiárias, cujas transformações refletem variações no status desta renda. Estas variações mostram-se pontos-chave para a compreensão das dinâmicas das escolhas alimentares, incluindo preferências, preparação e aquisição de alimentos. Concluímos que mesmo em contextos de restrição orçamentária, estas escolhas não se resumem à economia, sendo também orientadas por outros valores como a saúde, os gostos individuais, os pertencimentos sociais e a criatividade.
De artesãos a artistas: um estudo com ceramistas de Tonalá, México
Authors: Freitag Vanessa 
Published: May 2016

Pensar o trabalho artesanal de artesãos mexicanos que se inserem no circuito da arte (através de exposições artísticas e participação em concursos de artesanato) é a intenção deste artigo. Ao mesmo tempo, pretende repensar sobre como os conceitos de arte e artesanatoforam sendo construidos ideologicamente ao longo do tempo. Neste sentido, embora artesãos se destaquem por apresentar trabalhos com riqueza estética e conceitual, suas obras continuam sendo vistas e valorizadas socialmente como artesanato. Faz-se necessário criar um espaço para questionar os modos de ver o artesanato atualmente, levandoem consideração as diferentes tipologias que caracterizam o oficio.
Proceso de administración, producción y comercialización de queso en ASOPASN en el año 2013
Authors: Castillo Adriana Yamileth , Gámez Osegueda Jolimar Maykeling , Guevara Cruz Belkis Karina , Castillo Herrera Beverly 
Published: May 2016

En el presente estudio investigativo se realizó una evaluación del proceso de administración, producción y comercialización de queso de la asociación de programas agrícolas de san Nicolás (ASOPASN) en el año 2013. La investigación es del tipo cualitativo porque aborda a profundidad la problemática de Administración, producción y comercialización de queso en ASOPASN, para ello se hace una descripción holística y se analiza exhaustivamente el problema para sugerir una estrategia que mejore su funcionamiento. El universo de estudio estuvo conformada por la tienda la Garnacha, proyecto perteneciente a la Asociación de Programas Agrícolas de San Nicolás (ASOPANS) en el municipio de Estelí. Dentro de las mejoras que se deben hacer en esta asociación, está el seguimiento al proceso de administración en las principales actividades que se realizan, en el proceso de producción velar por el cumplimiento de las buenas prácticas de manufactura (BPM), así mismo en el proceso de comercialización se debe de garantizar el cumplimiento de las normas exigidas por el ministerio de salud (MINSA) para que de esta manera se pueda obtener la renovación del registro sanitario que actualmente se encuentra suspendido por el incumplimiento de algunos requisitos establecidos por el ministerio de salud.
Dissolved black carbon in Antarctic lakes: Chemical signatures of past and present sources
Authors: Khan Alia L. , Jaffé Rudolf , Ding Yan , McKnight Diane M. 
Published: May 2016

AbstractThe perennially ice‐covered, closed‐basin lakes in the McMurdo Dry Valleys, Antarctica, serve as sentinels for understanding the fate of dissolved black carbon from glacial sources in aquatic ecosystems. Here we show that dissolved black carbon can persist in freshwater and saline surface waters for thousands of years, while preserving the chemical signature of the original source materials. The ancient brines of the lake bottom waters have retained dissolved black carbon with a woody chemical signature, representing long‐range transport of black carbon from wildfires. In contrast, the surface waters are enriched in contemporary black carbon from fossil fuel combustion. Comparison of samples collected 25 years apart from the same lake suggests that the enrichment in anthropogenic black carbon is recent. Differences in the chemical composition of dissolved black carbon among the lakes are likely due to biogeochemical processing such as photochemical degradation and sorption on metal oxides.
Reproducing the observed energy‐dependent structure of Earth's electron radiation belts during storm recovery with an event‐specific diffusion model
Authors: Ripoll J.‐F. , Reeves G. D. , Cunningham G. S. , Loridan V. , Denton M. , Santolík O. , Kurth W. S. , Kletzing C. A. , Turner D. L. , Henderson M. G. , Ukhorskiy A. Y. 
Published: May 2016

AbstractWe present dynamic simulations of energy‐dependent losses in the radiation belt “slot region” and the formation of the two‐belt structure for the quiet days after the 1 March storm. The simulations combine radial diffusion with a realistic scattering model, based data‐driven spatially and temporally resolved whistler‐mode hiss wave observations from the Van Allen Probes satellites. The simulations reproduce Van Allen Probes observations for all energies and L shells (2–6) including (a) the strong energy dependence to the radiation belt dynamics (b) an energy‐dependent outer boundary to the inner zone that extends to higher L shells at lower energies and (c) an “S‐shaped” energy‐dependent inner boundary to the outer zone that results from the competition between diffusive radial transport and losses. We find that the characteristic energy‐dependent structure of the radiation belts and slot region is dynamic and can be formed gradually in ~15 days, although the “S shape” can also be reproduced by assuming equilibrium conditions. The highest‐energy electrons (E > 300 keV) of the inner region of the outer belt (L ~ 4–5) also constantly decay, demonstrating that hiss wave scattering affects the outer belt during times of extended plasmasphere. Through these simulations, we explain the full structure in energy and L shell of the belts and the slot formation by hiss scattering during storm recovery. We show the power and complexity of looking dynamically at the effects over all energies and L shells and the need for using data‐driven and event‐specific conditions.
Methane fluxes from the sea to the atmosphere across the Siberian shelf seas
Authors: Thornton Brett F. , Geibel Marc C. , Crill Patrick M. , Humborg Christoph , Mörth Carl‐Magnus 
Published: May 2016

AbstractThe Laptev and East Siberian Seas have been proposed as a substantial source of methane (CH4) to the atmosphere. During summer 2014, we made unique high‐resolution simultaneous measurements of CH4 in the atmosphere above, and surface waters of, the Laptev and East Siberian Seas. Turbulence‐driven sea‐air fluxes along the ship's track were derived from these observations; an average diffusive flux of 2.99 mg m−2 d−1 was calculated for the Laptev Sea and for the ice‐free portions of the western East Siberian Sea, 3.80 mg m−2 d−1. Although seafloor bubble plumes were observed at two locations in the study area, our calculations suggest that regionally, turbulence‐driven diffusive flux alone accounts for the observed atmospheric CH4 enhancements, with only a local, limited role for bubble fluxes, in contrast to earlier reports. CH4 in subice seawater in certain areas suggests that a short‐lived flux also occurs annually at ice‐out.
Driving ionospheric outflows and magnetospheric O+ energy density with Alfvén waves
Authors: Chaston C. C. , Bonnell J. W. , Reeves G. D. , Skoug R. M. 
Published: May 2016

AbstractWe show how dispersive Alfvén waves observed in the inner magnetosphere during geomagnetic storms can extract O+ ions from the topside ionosphere and accelerate these ions to energies exceeding 50 keV in the equatorial plane. This occurs through wave trapping, a variant of “shock” surfing, and stochastic ion acceleration. These processes in combination with the mirror force drive field‐aligned beams of outflowing ionospheric ions into the equatorial plane that evolve to provide energetic O+ distributions trapped near the equator. These waves also accelerate preexisting/injected ion populations on the same field lines. We show that the action of dispersive Alfvén waves over several minutes may drive order of magnitude increases in O+ ion pressure to make substantial contributions to magnetospheric ion energy density. These wave accelerated ions will enhance the ring current and play a role in the storm time evolution of the magnetosphere.
Decadal trends in air‐sea CO2 exchange in the Ross Sea (Antarctica)
Authors: Tagliabue Alessandro , Arrigo Kevin R. 
Published: May 2016

AbstractHighly productive Antarctic shelf systems, like the Ross Sea, play important roles in regional carbon budgets, but the drivers of local variations are poorly quantified. We assess the variability in the Ross Sea carbon cycle using a regional physical‐biogeochemical model. Regionally, total partial pressure of CO2 (pCO2) increases are largely controlled by the biological pump and broadly similar to those in the offshore Southern Ocean. However, this masks substantial local variability within the Ross Sea, where interannual fluctuations in total pCO2 are driven by the biological pump and alkalinity, whereas those for anthropogenic pCO2 are related to physical processes. Overall, the high degree of spatial variability in the Ross Sea carbon cycle causes extremes in aragonite saturation that can be as large as long‐term trends. Therefore, Antarctic shelf polynya systems like the Ross Sea will be strongly affected by local processes in addition to larger‐scale phenomena.
Unaccounted variability in NH3 agricultural sources detected by IASI contributing to European spring haze episode
Authors: Fortems‐Cheiney A. , Dufour G. , Hamaoui‐Laguel L. , Foret G. , Siour G. , Van Damme M. , Meleux F. , Coheur P.‐F. , Clerbaux C. , Clarisse L. , Favez O. , Wallasch M. , Beekmann M. 
Published: May 2016

AbstractAmmonia (NH3), whose main source in the troposphere is agriculture, is an important gaseous precursor of atmospheric particulate matter (PM). We derived daily ammonia emissions using NH3 total columns measured from the Infrared Atmospheric Sounding Interferometer (IASI) on board Metop‐A, at a relatively high spatial resolution (grid cell of 0.5° × 0.5°). During the European spring haze episodes of 24–31 March 2012 and 8–15 March 2014, IASI reveals NH3 total column magnitudes highlighting higher NH3 emissions over central Europe (especially over Germany, Czech Republic, and eastern France) from the ones provided by the European reference European Monitoring and Evaluation Programme inventory. These ammonia emissions exhibit in addition a large day‐to‐day variability, certainly due to spreading practices. The increase of NH3 emissions in the model, that reaches +300% locally, leads to an increase of both NH3 and PM2.5 surface concentrations and allows for a better comparison with independent measurements (in terms of bias, root‐mean‐square error, and correlation). This study suggests that there are good prospects for better quantifying NH3 emissions by atmospheric inversions.
Thicknesses of mare basalts on the Moon from gravity and topography
Authors: Gong Shengxia , Wieczorek Mark A. , Nimmo Francis , Kiefer Walter S. , Head James W. , Huang Chengli , Smith David E. , Zuber Maria T. 
Published: May 2016

AbstractA new method of determining the thickness of mare basalts on the Moon is introduced that is made possible by high‐resolution gravity data acquired from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission. Using a localized multitaper spherical‐harmonic analysis, an effective density spectrum is calculated that provides an estimate of the average crustal density as a function of spherical harmonic degree. By comparing the observed effective density spectrum with one generated from a theoretical model, the thickness of mare basalts can be constrained. We assume that the grain density of the basalts is known from remote sensing data and petrologic considerations, we assign a constant porosity to the basalts, and we let both the thickness of the basalts and the density of the underlying crust vary. Using this method, the total thickness of basalts was estimated on the nearside hemisphere, yielding an average of 0.74 km with 1σ upper and lower bounds of 1.62 km and 100 m, respectively. The region of Marius Hills, which is a long‐lived volcanic complex, is found to have the thickest basalts, with an average of 2.86 km and 1σ limits of 3.65 and 1.02 km, respectively. The crust beneath the Mare Imbrium basalts is found to have an atypically high density of about 3000 kg m−3 that we interpret as representing a mafic, unfractured, impact melt sheet.
Heterogeneous Catalysis for Water Oxidation by an Iridium Complex Immobilized on Bipyridine‐Periodic Mesoporous Organosilica
Authors: Liu Xiao , Maegawa Yoshifumi , Goto Yasutomo , Hara Kenji , Inagaki Shinji 
Published: May 2016

AbstractHeterogenization of metal‐complex catalysts for water oxidation without loss of their catalytic activity is important for the development of devices simulating photosynthesis. In this study, efficient heterogeneous iridium complexes for water oxidation were prepared using bipyridine‐bridged periodic mesoporous organosilica (BPy‐PMO) as a solid chelating ligand. The BPy‐PMO‐based iridium catalysts (Ir‐BPy‐PMO) were prepared by postsynthetic metalation of BPy‐PMO and characterized through physicochemical analyses. The Ir‐BPy‐PMOs showed high catalytic activity for water oxidation. The turnover frequency (TOF) values for Ir‐BPy‐PMOs were one order of magnitude higher than those of conventional heterogeneous iridium catalysts. The reusability and stability of Ir‐BPy‐PMO were also examined, and detailed characterization was conducted using powder X‐ray diffraction, nitrogen adsorption, 13C DD MAS NMR spectroscopy, TEM, and XAFS methods.
Stereoselektive arenbildende Aldolkondensation: Synthese axial‐chiraler aromatischer Amide
Authors: Fäseke Vincent C. , Sparr Christof 
Published: May 2016

AbstractDas zunehmende Bewusstsein über die Bedeutung von Amid‐Atropisomeren erfordert die Entwicklung neuer Strategien für ihre selektive Herstellung. Hier wird eine enantioselektive Synthese aromatischer Amide durch die Amin‐katalysierte, arenbildende Aldolkondensation beschrieben. Die hohe Reaktivität von Glyoxylamid‐Substraten ermöglicht einen bemerkenswert effizienten Aufbau eines neuen aromatischen Ringes, der bei Raumtemperatur innerhalb von Minuten mit exzellenter Stereoselektivität erfolgt. Die hohen Rotationsbarrieren der reduzierten Produkte verdeutlichen den Nutzen dieser stabilen, räumlich geordneten, chiralen Bausteine.
Full Kinetics from First Principles of the Chlorine Evolution Reaction over a RuO2(110) Model Electrode
Authors: Exner Kai S. , Anton Josef , Jacob Timo , Over Herbert 
Published: May 2016

AbstractCurrent progress in modern electrocatalysis research is spurred by theory, frequently based on ab initio thermodynamics, where the stable reaction intermediates at the electrode surface are identified, while the actual energy barriers are ignored. This approach is popular in that a simple tool is available for searching for promising electrode materials. However, thermodynamics alone may be misleading to assess the catalytic activity of an electrochemical reaction as we exemplify with the chlorine evolution reaction (CER) over a RuO2(110) model electrode. The full procedure is introduced, starting from the stable reaction intermediates, computing the energy barriers, and finally performing microkinetic simulations, all performed under the influence of the solvent and the electrode potential. Full kinetics from first‐principles allows the rate‐determining step in the CER to be identified and the experimentally observed change in the Tafel slope to be explained.
Unveiling the Biosynthetic Pathway of the Ribosomally Synthesized and Post‐translationally Modified Peptide Ustiloxin B in Filamentous Fungi
Authors: Ye Ying , Minami Atsushi , Igarashi Yuya , Izumikawa Miho , Umemura Myco , Nagano Nozomi , Machida Masayuki , Kawahara Teppei , Shin‐ya Kazuo , Gomi Katsuya , Oikawa Hideaki 
Published: May 2016

AbstractThe biosynthetic machinery of the first fungal ribosomally synthesized and post‐translationally modified peptide (RiPP) ustiloxin B was elucidated through a series of gene inactivation and heterologous expression studies. The results confirmed an essential requirement for novel oxidases possessing the DUF3328 motif for macrocyclization, and highly unique side‐chain modifications by three oxidases (UstCF1F2) and a pyridoxal 5′‐phosphate (PLP)‐dependent enzyme (UstD). These findings provide new insight into the expression of the RiPP gene clusters found in various fungi.
Isolation and Asymmetric Total Synthesis of Perforanoid A
Authors: Lv Chao , Yan Xiaohui , Tu Qian , Di Yingtong , Yuan Chunmao , Fang Xin , Ben‐David Yaacove , Xia Lei , Gong Jianxian , Shen Yuemao , Yang Zhen , Hao Xiaojiang 
Published: May 2016

AbstractA novel limonoid, perforanoid A, was isolated, and an asymmetric total synthesis was achieved in 10 steps. The key steps are chiral tertiary aminonaphthol mediated enantioselective alkenylation of an aldehyde to an allylic alcohol, Pd‐catalyzed coupling of the allylic alcohol with vinyl ether to form the γ‐lactone ring, and cyclopentenone ring formation through a Rh‐catalyzed Pauson–Khand reaction. Preliminary studies show that perforanoid A is cytotoxic towards HEL, K562, and CB3 tumor cell lines.
An In‐tether Chiral Center Modulates the Helicity, Cell Permeability, and Target Binding Affinity of a Peptide
Authors: Hu Kuan , Geng Hao , Zhang Qingzhou , Liu Qisong , Xie Mingsheng , Sun Chengjie , Li Wenjun , Lin Huacan , Jiang Fan , Wang Tao , Wu Yun‐Dong , Li Zigang 
Published: May 2016

AbstractThe addition of a precisely positioned chiral center in the tether of a constrained peptide is reported, yielding two separable peptide diastereomers with significantly different helicity, as supported by circular dichroism (CD) and NMR spectroscopy. Single crystal X‐ray diffraction analysis suggests that the absolute configuration of the in‐tether chiral center in helical form is R, which is in agreement with theoretical simulations. The relationship between the secondary structure of the short peptides and their biochemical/biophysical properties remains elusive, largely because of the lack of proper controls. The present strategy provides the only method for investigating the influence of solely conformational differences upon the biochemical/biophysical properties of peptides. The significant differences in permeability and target binding affinity between the peptide diastereomers demonstrate the importance of helical conformation.
Gold(I)‐Catalyzed Generation of the Two Components of a Formal [4+2] Cycloaddition Reaction for the Synthesis of Tetracyclic Pyrano[2,3,4‐de]chromenes
Authors: Arto Tamara , Fañanás Francisco J. , Rodríguez Félix 
Published: May 2016

AbstractOrtho‐Alkynylbenzaldehydes have been widely used to generate isochromenylium derivatives through gold‐catalyzed cycloisomerization. These isochromenylium derivatives have been exploited as formal diene derivatives for reactions with different dienophiles. Herein, we describe the behavior of ortho‐alkynylsalicylaldehydes, a particular case of ortho‐alkynylbenzaldehydes. The gold‐catalyzed cycloisomerization of ortho‐alkynylsalicylaldehydes delivers an unusual heterodiene derivative that reacts with electron‐rich alkenes through a formal [4+2] cycloaddition. In this reaction, both the diene and dienophile are generated in situ through gold‐catalyzed cycloisomerization of appropriate alkynamines or alkynols. This reaction was used to synthesize complex tetracyclic pyrano[2,3,4‐de]chromenes from two very simple starting materials (an ortho‐alkynylsalicylaldehyde and an alkynamine or alkynol) with complete atom economy and with selective formation of bonds, cycles, and stereocenters.
Immobilization of phosphotungstic acid in an amino‐containing metal–organic framework for oxidative desulfurization
Authors: Zhang Liwei , Wu Songhai , Liu Yong , Wang Feifei , Han Xu , Shang Hongyu 
Published: May 2016

A composite material has been successfully synthesized using an amino‐containing metal–organic framework (NH2‐MOF) and phosphotungstic acid (PTA). This composite was characterized using X‐ray diffraction, high‐resolution transmission electron microscopy, nitrogen adsorption–desorption measurements, Fourier transform infrared spectroscopy and X‐ray fluorescence. Characterization results confirmed the immobilization and good distribution of PTA in the NH2‐MOF. The PTA/NH2‐MOF was subsequently applied in the oxidative desulfurization of dibenzothiophene (DBT) with H2O2 as the oxidant in n‐octane under atmospheric conditions. Under optimal reaction conditions, the oxidative desulfurization conversion of DBT reached 100%, and there was no significant decrease of the catalytic activity after four recycles. Kinetic experiments were also performed for the reaction at various temperatures, which indicated that oxidative reaction rates followed pseudo first‐order kinetics, and the apparent activation energy for the desulfurization reaction was 34.1 kJ mol−1. The results indicated that this material exhibited excellent catalytic performance for oxidative desulfurization of DBT. Copyright © 2016 John Wiley & Sons, Ltd.