bluuebunny/crossref_metadata_2025 huggingface dataset:
ESTRATÉGIAS METAFICCIONAIS EM DOIS CONTOS DE EDGAR ALLAN POE: A RELAÇÃO ENTRE O LEITOR, O “RETRATO”, E A “CASA”
Authors: Parisi Leonardo , Azerêdo Genilda
Published: June 2016

Este artigo tem por objetivo analisar a presença de recursos metaficcionais em dois contos de Edgar Allan Poe: O Retrato Ovalado e A Queda da Casa de Usher. Estas narrativas apresentam diferentes formas de representação de recursos metaficcionais, permitindo uma ampla visão de como tais recursos podem ser desenvolvidos na literatura. A autorreflexão e a autoconsciência, como técnicas exploradas em obras metaficcionais, apresentam uma instigante maneira de se ler literatura, na qual a participação do leitor é peça fundamental. Um crescente número de romances que se utilizam dessas técnicas metaficcionais surgiu no século XX, como parte do movimento pós-modernista, assim como uma sistematização teórica sobre o tema e suas influências na literatura. Contudo, o uso da metaficção pode ser encontrado em narrativas bem mais antigas, como em muitos trabalhos de grandes escritores, como Cervantes, Machado de Assis, e Edgar Allan Poe, sendo os dois últimos importantes nomes da literatura do século XIX.
A NOSTALGIA COMO REFÚGIO DE UM PRESENTE DECADENTE EM O JARDIM DAS CEREJEIRAS DE TCHEKHOV
Authors: Gomes Analice de Sousa , Ribeiro Renata Rocha
Published: June 2016

O presente trabalho tem por objetivo destacar a composição temática e formal da Comédia O Jardim das Cerejeiras de Tchekhov. Inicialmente nos situamos quanto ao contexto histórico da Rússia no final do século XIX, momento social de transformações e marcado por um deslocamento abrupto do indivíduo, que não mais reconhece o lugar onde está social e psicologicamente, mantendo-o em completa inação e distante das relações intersubjetivas, isto é, entregue num estado de renúncia e nostalgia. Logo após, propõe-se a identificação do tipo de realismo que permeia a construção dramática da obra, compreendendo o jogo irônico de Tchekhov para a representação do contexto sócio-histórico vigente em sua época, que assinala sua produção e contribui para a crise formal do drama moderno. O trabalho analisa como o sentimento nostálgico de uma família aristocrática em decadência que, funciona como temática da peça, se precipita e determina a forma desta Comédia: a renúncia ao diálogo e ao presente, bem como, a inação predominante na construção das personagens. Deste modo, por se caracterizar como uma pesquisa bibliográfica, nos baseamos nos pressupostos teóricos de Szondi (2001/2011), Lima (2010), Bornheim (2007), Sachs (2011), Gonçalves (2011), dentre outros.
AVALIAÇÃO DA VELOCIDADE ESPECÍFICA DE CRESCIMENTO RADIAL DE FUNGOS EM ÓLEO VEGETAL RESIDUAL
Authors: Costa Tania Maria , Costa Sperb João Guilherme , Roncheti André Lima , Botelho Tatiani Karini Rensi , Sell Thais Marly , Bertoli Sávio Leandro , Tavares Lorena Benathar Ballod
Published: June 2016

A quantidade de resíduos oleosos gerados diariamente por indústrias de distintas áreas e o descarte inadequado de óleos residuais em ambientes domésticos e em ambientes naturais têm ocasionado preocupação mundial, devido à extensão dos danos ambientais causados por estes poluentes. Distintos fungos apresentam potencial de crescimento quando cultivados em ambientes contendo substratos oleosos. O crescimento micelial radial, bem como a cinética e a velocidade específica de crescimento de fungos filamentosos isolados de resíduos do processamento de óleo vegetal e de petróleo, foram avaliados em placas de Petri contendo óleo de soja virgem ou óleo de soja residual. Dentre os 24 fungos testados, foram identificados os dos gêneros Penicillium, Rhizopus, Aspergillus e Scopulariopsis. Os fungos LEB 025, 029, 033, 039, 040, 042 e 044 apresentaram as velocidades específicas máximas de crescimento estimuladas pela presença de óleo de soja residual, não havendo inibição de crescimento para qualquer estirpe estudada. Estes resultados sugerem que os fungos avaliados neste estudo, podem apresentar potencial para aplicação em processos de biorremediação de ambientes contaminados com óleos residuais, bem como sua utilização na síntese de compostos como enzimas lipolíticas e biossurfactantes.
SÍNTESE DE BIODIESEL A PARTIR DE RESÍDUOS GORDUROSOS DE FRITURA UTILIZANDO COMO FERRAMENTA PLANEJAMENTO FATORIAL
Authors: Tintor Cleiton Barcot , Hirata Daniela Battaglia , Pereira Ernandes Benedito
Published: June 2016

O objetivo deste trabalho foi a produção de biodiesel via rota enzimática, utilizando resíduo gorduroso de fritura como substrato e o planejamento fatorial como ferramenta de análise. O planejamento fatorial foi empregado para avaliar os parâmetros da reação de transesterificação, quanto à razão molar óleo:etanol (1:3; 1:4,7; 1:9; 1:13,3 e 1:15) e temperatura (30, 34, 45, 56 e 60ºC). A reação foi conduzida em shaker, usando 20 g do meio reaciona e 2 g do derivado imobilizado de lipase durante 15h. Os diferentes ensaios foram avaliados por cromatografia gasosa (verificação do teor de ésteres de etila) e viscosímetro, mostrando uma produção de 67,9% de ésteres de etila para a razão molar óleo:etanol de 1:4,7 e 34ºC de temperatura; e uma viscosidade de 3,82 cP para a razão molar óleo:etanol de 1:3 e 45ºC de temperatura, sendo estes os melhores resultados, indicando que a variável que interferiu significativamente no rendimento da reação foi a temperatura.
Study of the solar flares effect on VLF radio signal propagating along NRK‐ALG path using LWPC code
Authors: Bouderba Y. , NaitAmor S. , Tribeche M.
Published: June 2016

The X‐ray solar flare emissions penetrate down into the D region of the ionosphere (60–90 km of altitude) and affect the propagating very low frequency (VLF) radio signal. In this paper, we will present the effect of the solar flares on the signal mode composition of the NRK‐ALG path during the period from 2007 to 2013. In the Long Wave Propagating Capability (LWPC) code theory, the VLF signal is a sum of discrete modes that propagate to the receiver with different attenuation coefficients. Therefore, an interest is given to the behavior of these coefficients under solar flares. Effectively, from the simulation, we give more explanations about the role of the signal mode composition on the fading displacement since this later is a consequence of the destructive modes interferences. Thus, the sign (positive or negative) of the perturbed signal parameters (amplitude and phase) is found to be depending on the distance between the transmitter and the receiver. Finally, we give the Wait parameters and the electron density variations as a function of solar flares.
Local time variations of high‐energy plasmaspheric ion pitch angle distributions
Authors: Sarno‐Smith Lois K. , Liemohn Michael W. , Skoug Ruth M. , Larsen Brian A. , Moldwin Mark B. , Katus Roxanne M. , Wygant John R.
Published: June 2016

Recent observations from the Van Allen Probes Helium Oxygen Proton Electron (HOPE) instrument revealed a persistent depletion in the 1–10 eV ion population in the postmidnight sector during quiet times in the 2 < L < 3 region. This study explores the source of this ion depletion by developing an algorithm to classify 26 months of pitch angle distributions measured by the HOPE instrument. We correct the HOPE low energy fluxes for spacecraft potential using measurements from the Electric Field and Waves (EFW) instrument. A high percentage of low count pitch angle distributions is found in the postmidnight sector coupled with a low percentage of ion distributions peaked perpendicular to the field line. A peak in loss cone distributions in the dusk sector is also observed. These results characterize the nature of the dearth of the near 90° pitch angle 1–10 eV ion population in the near‐Earth postmidnight sector. This study also shows, for the first time, low‐energy HOPE differential number fluxes corrected for spacecraft potential and 1–10 eV H+ fluxes at different levels of geomagnetic activity.
Axial‐type olivine crystallographic preferred orientations: The effect of strain geometry on mantle texture
Authors: Chatzaras Vasileios , Kruckenberg Seth C. , Cohen Shaina M. , Medaris L. Gordon , Withers Anthony C. , Bagley Brian
Published: June 2016

The effect of finite strain geometry on crystallographic preferred orientation (CPO) is poorly constrained in the upper mantle. Specifically, the relationship between shape preferred orientation (SPO) and CPO in mantle rocks remains unclear. We analyzed a suite of 40 spinel peridotite xenoliths from Marie Byrd Land, West Antarctica. X‐ray computed tomography allows for quantification of spinel SPO, which ranges from prolate to oblate shape. Electron backscatter diffraction analysis reveals a range of olivine CPO patterns, including A‐type, axial‐[010], axial‐[100], and B‐type patterns. Until now, these CPO types were associated with different deformation conditions, deformation mechanisms, or strain magnitudes. Microstructures and deformation mechanism maps suggest that deformation in all studied xenoliths is dominated by dislocation‐accommodated grain boundary sliding. For the range of temperatures (780–1200°C), extraction depths (39–72 km), differential stresses (2–60 MPa), and water content (up to 500 H/106Si) of the xenolith suite, variations in olivine CPO do not correlate with changes in deformation conditions. Here we establish for the first time in naturally deformed mantle rocks that finite strain geometry controls the development of axial‐type olivine CPOs; axial‐[010] and axial‐[100] CPOs form in relation to oblate and prolate fabric ellipsoids, respectively. Girdling of olivine crystal axes results from intracrystalline slip with activation of multiple slip systems and grain boundary sliding. Our results demonstrate that mantle deformation may deviate from simple shear. Olivine texture in field studies and seismic anisotropy in geophysical investigations can provide critical constraints for the 3‐D strain in the upper mantle.
Relevance of infragravity waves in a wave‐dominated inlet
Authors: Bertin Xavier , Olabarrieta Maitane
Published: June 2016

This study investigates the relevance of infragravity (IG) waves at Albufeira Lagoon Inlet, a shallow wave‐dominated inlet located on the western coast of Portugal. A field experiment carried out in September 2010 revealed the occurrence of low‐frequency oscillations (i.e., 25–300 s) in water levels and current velocities. While these fluctuations were present over the ebb‐tidal delta along the whole tidal cycle, they only appeared between the beginning of the flood and up to 2 h after high tide inside the lagoon. The XBeach modeling system was applied to Albufeira Lagoon Inlet and reproduced the generation and propagation of IG waves and their blocking during the ebb. This behavior was explained by blocking due to opposing tidal currents reaching 2.5 m s−1 in shallow water depths. Numerical results suggest that the breakpoint mechanism and the long bound wave shoaling mechanisms contributed significantly to the generation of IG waves in the inlet. IG waves induced fluctuations in flood currents inside the lagoon reaching temporarily 100% of their magnitude. The fact that these fluctuations occur mostly at flood and not at ebb could promote flood dominance in the lagoon. This hypothesis will have to be verified, namely under storm wave conditions.
Spatiotemporal characteristics of ultraviolet radiation in recent 54 years from measurements and reconstructions over the Tibetan Plateau
Authors: Liu H. , Hu B. , Zhang L. , Wang Y. S. , Tian P. F.
Published: June 2016

Based on measurements of ultraviolet radiation (UV) for the period of 2005–2014 that were obtained from the Chinese Ecosystem Research Network, we developed an efficient model to estimate UV radiation under various sky conditions. This model can provide an accurate reconstruction of UV radiation data with absolute mean bias error less than 9.65%. We combined this reconstruction model with a hybrid model to obtain the historical data set of daily UV radiation from 1961 to 2014 at 37 weather stations belonging to the China Meteorological Administration over the Tibetan Plateau (TP). Based on the historical data set, the spatial distribution and temporal variation of UV radiation over the TP region were discussed. The decreasing and increasing periods of ultraviolet radiation over the TP were significantly different from those over the entire China. There was an increasing trend in UV radiation over the TP from 1961 to 1983, followed by a decreasing one until 2014, while UV radiation decreased from 1961 to 1989 and then increased slightly after 1989 for the entire China. The average UV radiation values in the increasing and decreasing periods over the TP were 0.598 MJ · m−2 · d−1 and 0.594 MJ · m−2 · d−1, respectively. In addition, aerosol optical depth, column ozone, and cloud prevent approximately 7.13%, 1.31%, and 15.05% of UV radiation reaching the Earth's surface, respectively.
Response of anaerobic ammonium oxidation to inorganic nitrogen fluctuations in temperate estuarine sediments
Authors: Teixeira Catarina , Magalhães Catarina , Joye Samantha B. , Bordalo Adriano A.
Published: June 2016

The discovery of anaerobic ammonium oxidation (anammox) highlighted the importance of alternative metabolic pathways to inorganic nitrogen removal in natural environments, particularly in those subjected to increased nitrate inputs, such as estuaries. Laboratory enrichment experiments were used to test the effect of increasing loads of nitrate (NO3−), nitrite (NO2−), and ammonium (NH4+) on the anammox process. Three Atlantic temperate estuaries (NW Portugal) were investigated along a salinity gradient, and anammox activity was measured under different NO3−, NO2−, and NH4+ treatments, using the isotope pairing technique. Obtained results showed that NO3− stimulated denitrification but not anammox, whereas NO2− additions had a positive effect on anammox activity, confirming its role as a key environmental control. On the other hand, increasing NH4+ concentrations seemed to inhibit anammox for low salinity sites. Our findings suggested an important role of the natural availability of nitrogen compounds in regulating anammox and the magnitude of anammox versus denitrification in estuarine environments.
Review and perspectives: Understanding natural‐hazards‐generated ionospheric perturbations using GPS measurements and coupled modeling
Authors: Komjathy Attila , Yang Yu‐Ming , Meng Xing , Verkhoglyadova Olga , Mannucci Anthony J. , Langley Richard B.
Published: June 2016

Natural hazards including earthquakes, volcanic eruptions, and tsunamis have been significant threats to humans throughout recorded history. Global navigation satellite systems (GNSS; including the Global Positioning System (GPS)) receivers have become primary sensors to measure signatures associated with natural hazards. These signatures typically include GPS‐derived seismic deformation measurements, coseismic vertical displacements, and real‐time GPS‐derived ocean buoy positioning estimates. Another way to use GPS observables is to compute the ionospheric total electron content (TEC) to measure, model, and monitor postseismic ionospheric disturbances caused by, e.g., earthquakes, volcanic eruptions, and tsunamis. In this paper, we review research progress at the Jet Propulsion Laboratory and elsewhere using examples of ground‐based and spaceborne observation of natural hazards that generated TEC perturbations. We present results for state‐of‐the‐art imaging using ground‐based and spaceborne ionospheric measurements and coupled atmosphere‐ionosphere modeling of ionospheric TEC perturbations. We also report advancements and chart future directions in modeling and inversion techniques to estimate tsunami wave heights and ground surface displacements using TEC measurements and error estimates. Our initial retrievals strongly suggest that both ground‐based and spaceborne GPS remote sensing techniques could play a critical role in detection and imaging of the upper atmosphere signatures of natural hazards including earthquakes and tsunamis. We found that combining ground‐based and spaceborne measurements may be crucial in estimating critical geophysical parameters such as tsunami wave heights and ground surface displacements using TEC observations. The GNSS‐based remote sensing of natural‐hazard‐induced ionospheric disturbances could be applied to and used in operational tsunami and earthquake early warning systems.
Evolution of the 2014–2015 sea surface temperature warming in the central west coast of Baja California, Mexico, recorded by remote sensing
Authors: Robinson Carlos J.
Published: June 2016

Extraordinarily warm sea surface temperatures were present in the California Current System during 2014–2015. In several locations surface waters temperature registered new record high in the recent time series. This study focuses in the evolution of the warming in the southern part of the California Current System (CCS), off the west coast of Baja California, Mexico. Analysis of monthly sea surface temperature (SST), sea level pressure, and wind speed as measured by satellite from January 1988 to December 2015 show that recent warming occurred during two distinct periods. From May 2014 to April 2015, SST warming was related to weak coastal winds not associated to El Niño. During this period occurred the longest sustained record of 15 months of negative wind anomalies in the series. A reduction of wind stress suggests a weakened coastal upwelling, and consequently, cold water not transported into the surface. The second process of warming occurred from September to December 2015, during a strong El Niño condition.
Thermal equation of state of hcp‐iron: Constraint on the density deficit of Earth's solid inner core
Authors: Fei Yingwei , Murphy Caitlin , Shibazaki Yuki , Shahar Anat , Huang Haijun
Published: June 2016

We conducted high‐pressure experiments on hexagonal close packed iron (hcp‐Fe) in MgO, NaCl, and Ne pressure‐transmitting media and found general agreement among the experimental data at 300 K that yield the best fitted values of the bulk modulus K0 = 172.7(±1.4) GPa and its pressure derivative K0′ = 4.79(±0.05) for hcp‐Fe, using the third‐order Birch‐Murnaghan equation of state. Using the derived thermal pressures for hcp‐Fe up to 100 GPa and 1800 K and previous shockwave Hugoniot data, we developed a thermal equation of state of hcp‐Fe. The thermal equation of state of hcp‐Fe is further used to calculate the densities of iron along adiabatic geotherms to define the density deficit of the inner core, which serves as the basis for developing quantitative composition models of the Earth's inner core. We determine the density deficit at the inner core boundary to be 3.6%, assuming an inner core boundary temperature of 6000 K.
Climate model biases in jet streams, blocking and storm tracks resulting from missing orographic drag
Authors: Pithan Felix , Shepherd Theodore G. , Zappa Giuseppe , Sandu Irina
Published: June 2016

State‐of‐the art climate models generally struggle to represent important features of the large‐scale circulation. Common model deficiencies include an equatorward bias in the location of the midlatitude westerlies and an overly zonal orientation of the North Atlantic storm track. Orography is known to strongly affect the atmospheric circulation and is notoriously difficult to represent in coarse‐resolution climate models. Yet how the representation of orography affects circulation biases in current climate models is not understood. Here we show that the effects of switching off the parameterization of drag from low‐level orographic blocking in one climate model resemble the biases of the Coupled Model Intercomparison Project Phase 5 ensemble: An overly zonal wintertime North Atlantic storm track and less European blocking events, and an equatorward shift in the Southern Hemispheric jet and increase in the Southern Annular Mode time scale. This suggests that typical circulation biases in coarse‐resolution climate models may be alleviated by improved parameterizations of low‐level drag.
Break of slope in earthquake size distribution and creep rate along the San Andreas Fault system
Authors: Vorobieva Inessa , Shebalin Peter , Narteau Clément
Published: June 2016

Crustal faults accommodate slip either by a succession of earthquakes or continuous slip, and in most instances, both these seismic and aseismic processes coexist. Recorded seismicity and geodetic measurements are therefore two complementary data sets that together document ongoing deformation along active tectonic structures. Here we study the influence of stable sliding on earthquake statistics. We show that creep along the San Andreas Fault is responsible for a break of slope in the earthquake size distribution. This slope increases with an increasing creep rate for larger magnitude ranges, whereas it shows no systematic dependence on creep rate for smaller magnitude ranges. This is interpreted as a deficit of large events under conditions of faster creep where seismic ruptures are less likely to propagate. These results suggest that the earthquake size distribution does not only depend on the level of stress but also on the type of deformation.
Million year old ice found under meter thick debris layer in Antarctica
Authors: Bibby Theodore , Putkonen Jaakko , Morgan Daniel , Balco Greg , Shuster David L.
Published: June 2016

Cosmogenic nuclide measurements associated with buried glacier ice in Ong Valley, in the Transantarctic Mountains, suggest the preservation of ancient ice. There are three glacial tills on the valley floor which have formed from the concentration of regolith contained within sublimating glacier ice. Two tills are less than 1 m thick and underlain by ice. Measurements of cosmogenic 10Be, 26Al, and 21Ne show that (i) the youngest buried ice unit and corresponding till are at least 11–13 ka, (ii) another ice unit and corresponding intermediate‐age till are at least 1.1 Ma old under any circumstances and most likely older than 1.78 Ma, and (iii) the oldest till is at least 1.57 Ma and most likely greater than 2.63 Ma. These observations highlight the longevity of ice under thin debris layers and the potential to sample ancient ice for paleoclimate/paleoatmosphere information close to the present land surface.
The interplay of the solar wind proton core and halo populations: EMIC instability
Authors: Shaaban S. M. , Lazar M. , Poedts S. , Elhanbaly A.
Published: June 2016

The kinetic properties of the solar wind protons (ions), like their temperature anisotropy and the resulting instabilities, are, in general, investigated considering only the proton core (or thermal) populations. The implication of the suprathermal halo components is minimized or just ignored, despite the fact that their presence in the solar wind is continuously reported by the observations, and their kinetic energy density may be significant. Whether they are originating in the corona or solar wind, the energetic particles may result from acceleration by the plasma turbulence or from the pitch angle scattering of the streaming protons by the self‐generated fluctuations. The presence of suprathermal protons in the heliosphere suggests, therefore, a direct implication in resonant interactions, e.g., Landau and cyclotron, with plasma particles. This paper presents the results of a first investigation on the interplay of the proton core and suprathermal halo, when both these two populations may exhibit temperature anisotropies, which destabilize the electromagnetic ion (proton) cyclotron (EMIC) modes. These results clearly show that for conditions typically encountered in the solar wind, the effects of the suprathermals can be more important than those driven by the core. Remarkable are also the cumulative effects of the core and halo components, which change dramatically the instability conditions.
Lithosphere delamination in continental collisional orogens: A systematic numerical study
Authors: Li Zhong‐Hai , Liu Mian , Gerya Taras
Published: June 2016

Lithosphere delamination is believed to have played a major role in mountain building; however, the mechanism and dynamics of delamination remain poorly understood. Using a 2‐D high‐resolution thermomechanical model, we systematically investigated the conditions for the initiation of lithosphere delamination during orogenesis of continental collision and explored the key factors that control the various modes of delamination. Our results indicate that the negative buoyancy from lithosphere thickening during orogenesis could cause delamination, when the reference density of the lithospheric mantle is not lower than that of the asthenosphere. In these cases, compositional rejuvenation of depleted continental lithosphere by magmatic/metasomatic plume‐ and/or subduction‐induced processes may play crucial roles for subsequent lithosphere delamination. If the reference density of the lithospheric mantle is less than that of the asthenosphere, additional promoting factors, such as lower crust eclogitization, are required for delamination. Our numerical simulations predict three basic modes of lithosphere delamination: pro‐plate delamination, retro‐plate delamination, and a transitional double‐plates (both the pro‐plate and retro‐plate) delamination. Pro‐plate delamination is favored by low convergence rates, high lithospheric density, and relatively strong retro‐plate, whereas retro‐plate delamination requires a weak retro‐plate. The Northern Apennines and Central Northern Tibetan Plateau are possible geological analogs for the pro‐plate and retro‐plate delamination modes, respectively. Our model also shows significant impact of delamination on the topographic evolution of orogens. Large‐scale lithosphere delamination in continental collision zones would lead to wide and flat plateaus, whereas relatively narrow and steep mountain belts are predicted in orogens without major delamination.
The sensitivity of southeastern United States climate to varying irrigation vigor
Authors: Selman Christopher , Misra Vasubandhu
Published: June 2016

Four regional climate model runs centered on the Southeast United States (SEUS) assuming a crop growing season of May through October are irrigated at 25% (IRR25), 50% (IRR50), 75% (IRR75), and 100% (IRR100) of the root zone porosity to assess the sensitivity of the SEUS climate to irrigation. A fifth run, assuming no irrigation (CTL), is used as the basis for comparison. Across all IRR runs, it is found that there is a general reduction in seasonal mean precipitation over the irrigated cells relative to CTL. This manifests as an increase in dry (0–1 mm/d) days and reduction in > 1 mm/d rainfall events. A comparative moisture budget reveals that area‐averaged precipitation over the irrigated cells displays a reduction in precipitation and runoff in IRR100 with a weaker reduction in IRR25. This is despite an increase in vertically integrated moisture convergence and local evaporation. We find that irrigation increases the lower atmospheric stability, which in turn reduces the convective rainfall over the irrigated areas. Seasonally averaged temperatures reduce over irrigated areas, with the intensity of the reduction increasing with irrigation vigor. This is largely attributed to a repartitioning of sensible heat flux into latent heat flux. There is also, however, a small increase of heat flow to deeper soil layers. Precipitation ahead of transient cold fronts is also reduced by irrigation as they pass over irrigated cells, owing to the increased stability in the lower troposphere. The intensity of this precipitation reduction becomes more intense as irrigation vigor increases. Lastly, heat waves in the SEUS are reduced in intensity over irrigated cells.
The boreal winter Madden‐Julian Oscillation's influence on summertime precipitation in the greater Caribbean
Authors: Curtis Scott , Gamble Douglas W.
Published: June 2016

Precipitation totals in the greater Caribbean are known to be affected by interannual variability. In particular, dry conditions in the spring‐summer have been physically linked to the positive phase of North Atlantic Oscillation (NAO) in the literature. In this study, it was found through regression analysis that an active Madden‐Julian Oscillation (MJO) in winter geographically focused over the Maritime Continent contributes to a positive NAO in March via the generation of Rossby waves in the Northern Hemisphere. Specifically, a negative Pacific‐North American pattern develops in the winter and transitions to an Atlantic pattern in spring. The positive NAO is a transient feature of this evolving wave train, but a center of significant positive 200 hPa geopotential heights is entrenched over the southeast U.S. throughout the February to May time period and is manifested as high pressure at the surface. The southern flank of this system increases the speeds of the trade winds and leads to a cooling of the Caribbean sea surface temperatures and, thus, convection suppression and reduced precipitation. Thus, this study advances our understanding of the climate of the greater Caribbean by using climate teleconnections to relate the MJO to rainfall in the region.
Structure and composition of the distant lunar exosphere: Constraints from ARTEMIS observations of ion acceleration in time‐varying fields
Authors: Halekas J. S. , Poppe A. R. , Farrell W. M. , McFadden J. P.
Published: June 2016

By analyzing the trajectories of ionized constituents of the lunar exosphere in time‐varying electromagnetic fields, we can place constraints on the composition, structure, and dynamics of the lunar exosphere. Heavy ions travel slower than light ions in the same fields, so by observing the lag between field rotations and the response of ions from the lunar exosphere, we can place constraints on the composition of the ions. Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) provides an ideal platform to utilize such an analysis, since its two‐probe vantage allows precise timing of the propagation of field discontinuities in the solar wind, and its sensitive plasma instruments can detect the ion response. We demonstrate the utility of this technique by using fully time‐dependent charged particle tracing to analyze several minutes of ion observations taken by the two ARTEMIS probes ~3000–5000 km above the dusk terminator on 25 January 2014. The observations from this time period allow us to reach several interesting conclusions. The ion production at altitudes of a few hundred kilometers above the sunlit surface of the Moon has an unexpectedly significant contribution from species with masses of 40 amu or greater. The inferred distribution of the neutral source population has a large scale height, suggesting that micrometeorite impact vaporization and/or sputtering play an important role in the production of neutrals from the surface. Our observations also suggest an asymmetry in ion production, consistent with either a compositional variation in neutral vapor production or a local reduction in solar wind sputtering in magnetic regions of the surface.
Twelve year interannual and seasonal variability of stream carbon export from a boreal peatland catchment
Authors: Leach J. A. , Larsson A. , Wallin M. B. , Nilsson M. B. , Laudon H.
Published: June 2016

Understanding stream carbon export dynamics is needed to accurately predict how the carbon balance of peatland catchments will respond to climatic and environmental change. We used a 12 year record (2003–2014) of continuous streamflow and manual spot measurements of total organic carbon (TOC), dissolved inorganic carbon (DIC), methane (CH4), and organic carbon quality (carbon‐specific ultraviolet absorbance at 254 nm per dissolved organic carbon) to assess interannual and seasonal variability in stream carbon export for a peatland catchment (70% mire and 30% forest cover) in northern Sweden. Mean annual total carbon export for the 12 year period was 12.2 gCm−2 yr−1, but individual years ranged between 6 and 18 gCm−2 yr−1. TOC, which was primarily composed of dissolved organic carbon (>99%), was the dominant form of carbon being exported, comprising 63% to 79% of total annual exports, and DIC contributed between 19% and 33%. CH4 made up less than 5% of total export. When compared to previously published annual net ecosystem exchange (NEE) for the studied peatland system, stream carbon export typically accounted for 12 to 50% of NEE for most years. However, in 2006 stream carbon export accounted for 63 to 90% (estimated uncertainty range) of NEE due to a dry summer which suppressed NEE, followed by a wet autumn that resulted in considerable stream export. Runoff exerted a primary control on stream carbon export from this catchment; however, our findings suggest that seasonal variations in biologic and hydrologic processes responsible for production and transport of carbon within the peatland were secondary influences on stream carbon export. Consideration of these seasonal dynamics is needed when predicting stream carbon export response to environmental change.
On the utility of proxy system models for estimating climate states over the common era
Authors: Dee Sylvia G. , Steiger Nathan J. , Emile‐Geay Julien , Hakim Gregory J.
Published: June 2016

Paleoclimate data assimilation has recently emerged as a promising technique to estimate past climate states. Here we test two of the underlying assumptions of paleoclimate data assimilation as applied so far: (1) climate proxies can be modeled as linear, univariate recorders of temperature and (2) structural errors in GCMs can be neglected. To investigate these two points and related uncertainties, we perform a series of synthetic, paleoclimate data assimilation‐based reconstructions where “pseudo” proxies are generated with physically based proxy system models (PSMs) for coral δ18O, tree ring width, and ice core δ18O using two isotope‐enabled atmospheric general circulation models. For (1), we find that linear‐univariate models efficiently capture the GCM's climate in ice cores and corals and do not lead to large losses in reconstruction skill. However, this does not hold for tree ring width, especially in regions where the trees' response is dominated by moisture supply; we quantify how the breakdown of this assumption lowers reconstruction skill for each proxy class. For (2), we find that climate model biases can introduce errors that greatly reduce reconstruction skill, with or without perfect proxy system models. We explore possible strategies for mitigating structural modeling errors in GCMs and discuss implications for paleoclimate reanalyses.
Fingerprinting stress: Stylolite and calcite twinning paleopiezometry revealing the complexity of progressive stress patterns during folding—The case of the Monte Nero anticline in the Apennines, Italy
Authors: Beaudoin Nicolas , Koehn Daniel , Lacombe Olivier , Lecouty Alexandre , Billi Andrea , Aharonov Einat , Parlangeau Camille
Published: June 2016

In this study we show for the first time how quantitative stress estimates can be derived by combining calcite twinning and stylolite roughness stress fingerprinting techniques in a fold‐and‐thrust belt. First, we present a new method that gives access to stress inversion using tectonic stylolites without access to the stylolite surface and compare results with calcite twin inversion. Second, we use our new approach to present a high‐resolution deformation and stress history that affected Meso‐Cenozoic limestone strata in the Monte Nero Anticline during its late Miocene‐Pliocene growth in the Umbria‐Marche Arcuate Ridge (northern Apennines, Italy). In this area an extensive stylolite‐joint/vein network developed during layer‐parallel shortening (LPS), as well as during and after folding. Stress fingerprinting illustrates how stress in the sedimentary strata did build up prior to folding during LPS. The stress regime oscillated between strike slip and compressional during LPS before ultimately becoming strike slip again during late stage fold tightening. Our case study shows that high‐resolution stress fingerprinting is possible and that this novel method can be used to unravel temporal relationships that relate to local variations of regional orogenic stresses. Beyond regional implications, this study validates our approach as a new powerful toolbox to high‐resolution stress fingerprinting in basins and orogens combining joint and vein analysis with sedimentary and tectonic stylolite and calcite twin inversion techniques.
The importance of evolutionarily conserved C‐terminal basic residues for the stability of proapoptotic Bax protein
Authors: Rosas‐Trigueros Jorge L.
Published: June 2016

Bax is a protein that promotes apoptosis (a form of cell death). The atomistic details of the mechanism by which Bax is activated during apoptosis remain a subject of debate. C‐terminal basic residues in the sequence of Bax show remarkable conservation across a variety of species. The role of these charged residues in the stability of Bax was investigated by submitting substituted mutants to molecular dynamics simulations at high temperatures. Mutation of either or both K189 and K190 led to dramatic changes in helical content, radius of gyration, proximity of the C terminus to the core of the protein, exposure of the BH3 domain, and bundling of the core. These results suggest a critical role of positively charged residues close to the C terminus in the structural stability of Bax.
Triplet Energy Transfer from PbS(Se) Nanocrystals to Rubrene: the Relationship between the Upconversion Quantum Yield and Size
Authors: Mahboub Melika , Maghsoudiganjeh Hadi , Pham Andrew Minh , Huang Zhiyuan , Tang Ming Lee
Published: June 2016

Photon upconversion has attracted enormous attention due to its wide range of applications in biological imaging, photocatalysis, and especially photovoltaics. Here, the effect of quantum confinement on the efficiency of Dexter energy transfer from PbS and PbSe nanocrystals (NCs) to a rubrene acceptor is studied. A series of experiments exploring the relationship between NC size and the upconversion quantum yield (QY) in this hybrid platform show that energy transfer occurs in the Marcus normal regime. By decreasing the NC diameter from 3.5 to 2.9 nm for PbS and from 3.2 to 2.5 nm for PbSe, the relative upconversion QY is enhanced about 700 and 250‐fold respectively. In addition, the dynamic Stern–Volmer constant (KSV) for the quenching of PbSe NCs by rubrene increases approximately fivefold with a decrease in NC diameter from 3.2 to 2.5 nm to a value of 200 m−1. This work shows that high quality, well‐passivated, small NCs are critical for efficient triplet energy transfer to molecular acceptors.
High‐Sensitivity Floating‐Gate Phototransistors Based on WS2 and MoS2
Authors: Gong Fan , Luo Wenjin , Wang Jianlu , Wang Peng , Fang Hehai , Zheng Dingshan , Guo Nan , Wang Jingli , Luo Man , Ho Johnny C. , Chen Xiaoshuang , Lu Wei , Liao Lei , Hu Weida
Published: June 2016

In recent years, 2D layered materials have been considered as promising photon absorption channel media for next‐generation phototransistors due to their atomic thickness, easily tailored single‐crystal van der Waals heterostructures, ultrafast optoelectronic characteristics, and broadband photon absorption. However, the photosensitivity obtained from such devices, even under a large bias voltage, is still unsatisfactory until now. In this paper, high‐sensitivity phototransistors based on WS2 and MoS2 are proposed, designed, and fabricated with gold nanoparticles (AuNPs) embedded in the gate dielectric. These AuNPs, located between the tunneling and blocking dielectric, are found to enable efficient electron trapping in order to strongly suppress dark current. Ultralow dark current (10−11 A), high photoresponsivity (1090 A W−1), and high detectivity (3.5 × 1011 Jones) are obtained for the WS2 devices under a low source/drain and a zero gate voltage at a wavelength of 520 nm. These results demonstrate that the floating‐gate memory structure is an effective configuration to achieve high‐performance 2D electronic/optoelectronic devices.
Biomechanical Cell Regulation by High Aspect Ratio Nanoimprinted Pillars
Authors: Viela Felipe , Granados Daniel , Ayuso‐Sacido Angel , Rodríguez Isabel
Published: June 2016

High aspect ratio pillared topographies provide a large number of mechanical cues that cells can sense and react to. High aspect ratio pillars have been employed effectively to promote stem cell differentiation and to probe cellular tractions. Yet, the full potential of these topographies for mechanobiology remains insufficiently characterized. Here, the response of progenitor neural stem cells to dense high aspect ratio polymer pillars in the nano‐ and microscale is investigated. Thermal nanoimprinting is utilized to fabricate with high precision well‐defined pillars with high density and aspect ratio. Studies on cell viability, morphology, cell spreading, and migration are performed comparatively to a control flat substrate. The traction forces exerted by the cells on the pillar structures are probed quantitatively by a combined focused ion beam scanning electron microscopy (FIB‐SEM) technique. The cell responses observed are distinctive for each dimension, following the trend that an increase in aspect ratio and feature size from nano‐ to micronscale results in more confined cell morphology with large cytoplasmic penetrations and nuclear deformation. Accordingly, cells seeded on the micrometer scale topography show reduced mobility, a persistent quasi‐directional migration, high traction forces, and a lower rate of proliferation. Cells on the nanotopography show higher rate of proliferation, a large cell spread, high mobility with random migration altogether with lower traction forces.
State‐of‐the‐Art Neutral Tint Multichromophoric Polymers for High‐Contrast See‐Through Electrochromic Devices
Authors: Sassi Mauro , Salamone Matteo M. , Ruffo Riccardo , Patriarca Giorgio E. , Mari Claudio M. , Pagani Giorgio A. , Posset Uwe , Beverina Luca
Published: June 2016

Two new multichromophoric electrochromic polymers featuring a conjugated EDOT/ProDOT copolymer backbone (PXDOT) and a reversible Weitz‐type redox active small molecule electrochrome (WTE) tethered to the conjugated chain are reported here. The careful design of the WTEs provides a highly reversible redox behavior with a colorless red switching that complements the colorless blue switching of the conjugated backbone. Subtractive color mixing successfully provides high performing solution processable polymeric layers with colorless neutral tint switchable limiting states for application in see‐through electrochromic devices. Design, synthesis, comprehensive chemical and spectroelectrochemical characterization as well as the preparation of a proof‐of‐concept device are discussed.
Congenital immunodeficiency in an individual with Wiedemann–Steiner syndrome due to a novel missense mutation in KMT2A
Authors: Stellacci Emilia , Onesimo Roberta , Bruselles Alessandro , Pizzi Simone , Battaglia Domenica , Leoni Chiara , Zampino Giuseppe , Tartaglia Marco
Published: June 2016

Wiedemann–Steiner Syndrome (WSS) is an autosomal dominant disorder characterized by hypertrichosis, short stature, intellectual disability, developmental delay, and facial dysmorphism. Since the original reports by Wiedemann and co‐workers, and Steiner and Marques, only a few cases have been described. Recently, the clinical variability of the disorder has more precisely been characterized by Jones and co‐workers, who also identified heterozygous KMT2A mutations as the molecular defect underlying this condition. Here, we report on a boy with a complex phenotype overlapping WSS but exhibiting epilepsy, feeding difficulties, microcephaly, and congenital immunodeficiency with low levels of immunoglobulins as additional features. Whole exome sequencing allowed identifying a previously unreported de novo KMT2A missense mutation affecting the DNA binding domain of the methyltransferase. This finding expands the clinical phenotype associated with KMT2A mutations to include immunodeficiency and epilepsy as clinically relevant features for this disorder. © 2016 Wiley Periodicals, Inc.
Corneal clouding, cataract, and colobomas with a novel missense mutation inB4GALT7—a review of eye anomalies in the linkeropathy syndromes
Authors: Arunrut Teda , Sabbadini Marta , Jain Mahim , Machol Keren , Scaglia Fernando , Slavotinek Anne
Published: June 2016

We present a 5‐year‐old female with a distinctive phenotype comprising global developmental delays, pre‐ and post‐natal growth restriction, striking joint laxity with soft skin, and scoliosis. She had a triangular facies, a prominent forehead, proptosis, a small nose, and a small jaw. Her ocular findings included corneal clouding, colobomas of the iris and optic nerve, and posterior subcapsular cataracts. Exome sequencing identified homozygosity for c.970T>A, predicting p.(Cys324Ser), in the xylosylprotein 4‐beta‐galactosyltransferase, polypeptide 7 (B4GALT7) gene. Variant segregation was consistent with autosomal recessive inheritance and the missense substitution was predicted to be pathogenic. As the phenotype of this child is consistent with that described in other “linkeropathy” syndromes, we conclude that p.(Cys324Ser) is likely to be disease‐causing. The eye features were a notable part of this child's presentation and mutations in the linkeropathy genes (XYLT1,XYLT2,B4GALT7,B3GALT6, andB3GAT3) can be associated with ocular findings, including blue sclerae, refractive errors, corneal clouding, strabismus, nystagmus, cataracts, glaucoma, and retinal abnormalities, including retinal detachment. The corneal clouding and cataracts in this patient may thus have been caused by herB4GALT7mutation, but the colobomas are a novel phenotypic finding. However, a different genetic etiology or a role for modifying genetic factors has not been excluded in the etiology of her colobomas. © 2016 Wiley Periodicals, Inc.
Copper‐Catalyzed C(sp2)–C(sp3) Cross‐Dehydrogenative Coupling of Quinones with Cyclic Alkanes: One‐Step Access to Parvaquone and its Analogs
Authors: Baral Ek Raj , Kim Sung Hong , Lee Yong Rok
Published: June 2016

A copper‐catalyzed direct cross‐coupling reaction of quinones with cycloalkanes in the presence of tert‐butyl hydro peroxide was developed. This methodology allows the direct installation of cycloalkyl groups with medium‐ and large‐sized rings on 1,4‐naphthoquinones, anthracene‐1,4‐dione, or 1,4‐benzoquinones. Based on this new protocol, the one‐pot synthesis of the antimalarial drug, parvaquone, was achieved.
Hypervalent Iodine‐Catalyzed Synthesis of 1,2,4‐Oxadiazoles from Aldoximes and Nitriles
Authors: Yoshimura Akira , Nguyen Khiem C. , Klasen Scott C. , Postnikov Pavel S. , Yusubov Mekhman S. , Saito Akio , Nemykin Victor N. , Zhdankin Viktor V.
Published: June 2016

A convenient procedure for oxidative cycloaddition of aldoximes with nitriles using stoichiometric or catalytic amounts of hypervalent iodine(III) reagent IBA‐OTf (2‐iodosylbenzoic acid triflate) has been developed. This efficient procedure works well for the preparation of various 1,2,4‐oxadiazoles in generally high yields under mild reaction conditions. The actual oxidant in this reaction, IBA‐OTf, is prepared from 2‐iodosylbenzoic acid (IBA) and trifluoromethanesulfonic acid (TfOH) or it can be generated in situ from 2‐iodobenzoic acid and m‐chloroperoxybenzoic acid (m‐CPBA) in the presence of TfOH. The nature of hydroxy(aryl)iodonium species, generated in situ from 2‐iodobenzoic acid, m‐CPBA, and TfOH under catalytic reaction conditions, has been confirmed by 1H NMR spectroscopy, ESI‐mass spectrometry, and by X‐ray diffraction.