bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of remote-sensing reflectance to constrain a data assimilating marine biogeochemical model of the Great Barrier Reef
Authors: Jones Emlyn M. , Baird Mark E. , Mongin Mathieu , Parslow John , Skerratt Jenny , Lovell Jenny , Margvelashvili Nugzar , Matear Richard J. , Wild-Allen Karen , Robson Barbara , Rizwi Farhan , Oke Peter , King Edward , Schroeder Thomas , Steven Andy , Taylor John
Published: December 2016

Abstract. Skillful marine biogeochemical (BGC) models are required to understand a range of coastal and global phenomena such as changes in nitrogen and carbon cycles. The refinement of BGC models through the assimilation of variables calculated from observed in-water inherent optical properties (IOPs), such as phytoplankton absorption, is problematic. Empirically derived relationships between IOPs and variables such as chlorophyll-a concentration (Chl a), total suspended solids (TSS) and coloured dissolved organic matter (CDOM) have been shown to have errors that can exceed 100 % of the observed quantity. These errors are greatest in shallow coastal regions, such as the Great Barrier Reef (GBR), due to the additional signal from bottom reflectance. Rather than assimilate quantities calculated using IOP algorithms, this study demonstrates the advantages of assimilating quantities calculated directly from the less error-prone satellite remote-sensing reflectance (RSR). To assimilate the observed RSR, we use an in-water optical model to produce an equivalent simulated RSR and calculate the mismatch between the observed and simulated quantities to constrain the BGC model with a deterministic ensemble Kalman filter (DEnKF). The traditional assumption that simulated surface Chl a is equivalent to the remotely sensed OC3M estimate of Chl a resulted in a forecast error of approximately 75 %. We show this error can be halved by instead using simulated RSR to constrain the model via the assimilation system. When the analysis and forecast fields from the RSR-based assimilation system are compared with the non-assimilating model, a comparison against independent in situ observations of Chl a, TSS and dissolved inorganic nutrients (NO3, NH4 and DIP) showed that errors are reduced by up to 90 %. In all cases, the assimilation system improves the simulation compared to the non-assimilating model. Our approach allows for the incorporation of vast quantities of remote-sensing observations that have in the past been discarded due to shallow water and/or artefacts introduced by terrestrially derived TSS and CDOM or the lack of a calibrated regional IOP algorithm.
Arabian Sea upwelling over the last millennium and in the 21st century as simulated by Earth System Models
Authors: Yi Xing , Zorita Eduardo
Published: December 2016

Abstract. Arabian Sea upwelling in the past has been generally studied based on the sediment records. We apply two earth system models and analyse the simulated water vertical velocity to investigate the variations of the coastal upwelling in the western Arabian Sea over the last millennium. In addition, the same models, with slightly different configurations, are also employed to study the changes in upwelling in the 21st century under the strongest and the weakest greenhouse gas emission scenarios. With a negative long-term trend caused by the orbital forcing of the models, the upwelling over the last millennium is found to be closely correlated with the sea surface temperature, the Indian summer Monsoon and sediment records. The future upwelling under the Representative Concentration Pathway (RCP) 8.5 scenario reveals a negative trend, in contrast with the positive trend displayed by the upwelling favourable along-shore winds. Therefore, it is likely that other factors, like water stratification in the upper ocean layers caused by the stronger surface warming overrides the effect from the upwelling favourable wind. No significant trend is found for the upwelling under the RCP2.6 scenario, which is likely due to a compensation between the opposing effects of the increase in upwelling favourable winds and the stratification of the water column.
Multi-year Downscaling Application of Online Coupled WRFCMAQ
over East Asia for Regional Climate and Air Quality
Modeling: Model Evaluation and Aerosol Direct Effects
Authors: Hong Chaopeng , Zhang Qiang , Zhang Yang , Tang Youhua , Tong Daniel , He Kebin
Published: December 2016

Abstract. In this study, a regional coupled climate-chemistry modeling system using the dynamical downscaling technique was established by linking the global Community Earth System Model (CESM) and the regional online coupled Weather Research and Forecasting – Community Multiscale Air Quality (WRF-CMAQ) model for the purpose of comprehensive assessments of regional climate change and air quality and their interactions within one modeling framework. The modeling system was applied over East Asia for a multiyear climatological application during 2006–2010 driven with CESM downscaling data under Representative Concentration Pathway 4.5 (RCP 4.5) as well as a short-term air quality application in representative months in 2013 driven with a reanalysis dataset. A comprehensive model evaluation was conducted against observations from surface networks and satellite observations to assess the model's performance. This study presents the first application and evaluation of the online coupled WRF-CMAQ model for climatological simulations using the dynamical downscaling technique. The model was able to satisfactorily predict major meteorological variables. The improved statistical performance for the 2-m temperature (T2) in this study compared with the Coupled Model Inter-comparison Project Phase 5 (CMIP5) multi-models might be related to the use of the regional model WRF and the bias-correction technique applied for CESM downscaling. The model showed good ability to predict PM2.5 in winter and O3 in summer in terms of statistical performance and spatial distributions. Compared with global models that tend to underpredict PM2.5 concentrations in China, WRF-CMAQ was able to capture the high PM2.5 concentrations in urban areas. In general, the online coupled WRF-CMAQ model performed well for both climatological and air quality applications. The coupled modeling system with direct aerosol feedbacks predicted aerosol optical depth relatively well and significantly reduced the overprediction in downward shortwave radiation at the surface (SWDOWN) over polluted regions in China. The performance of cloud variables was not as good as other meteorological variables, and underpredictions of cloud fraction resulted in overpredictions of SWDOWN and underpredictions of shortwave and longwave cloud forcing. The importance of climate-chemistry interactions was demonstrated via the impacts of aerosol direct effects on climate and air quality. The aerosol effects on climate and air quality in East Asia were more significant than in other regions because of higher aerosol loadings that resulted from severe regional pollution, which indicates the need for applying online-coupled models over East Asia for regional climate and air quality modeling and to study the important climate-chemistry interactions.
Trajectory encounter number as a diagnostic of mixing potential in fluid flows
Authors: Rypina Irina I. , Pratt Larry J.
Published: December 2016

Abstract. Fluid parcels can exchange water properties when coming in contact with each other, leading to mixing. The trajectory encounter number, which quantifies the number of fluid parcel trajectories that pass close to a reference trajectory over a finite time interval, is introduced as a measure of the mixing potential of a flow. Regions characterized by low encounter numbers, such as cores of coherent eddies, have low mixing potential, whereas turbulent or chaotic regions characterized by large encounter numbers have high mixing potential. The encounter number diagnostic was used to characterize mixing potential in 3 flows of increasing complexity: the Duffing Oscillator, the Bickley Jet, and the altimetry-based velocity in the Gulf Stream Extension region. An additional example was presented where the encounter number was combined with the u-star-approach of Pratt et al., 2016 to characterize the mixing potential for a specific tracer distribution in the Bickley Jet flow. Analytical relationships were derived connecting encounter number to diffusivity for purely-diffusive flows, and to shear and strain rates for linear shear and linear strain flows, respectively. It is shown that in a diffusive regime the encounter number grows as a square-root of time, whereas in a linear shear and strain flows the encounter number is proportional to time.
Bifenilos policlorados y disrupción endocrina en la fauna salvaje
Authors: Hernández-Moreno David , Míguez-Santiyán María P. , Oropesa-Jiménez Ana L. , Soler-Rodríguez Francisco , Van Wyk J.H. , Pérez-López Marcos
Published: December 2016

Los Bifenilos Policlorados son una amplia familia de contaminantes ambientales persistentes de enorme relevancia ambiental, pues a pesar de estar prohibidos, siguen encontrándose en concentraciones preocupantes en el medio ambiente, suficientes como para desencadenar programas de biomonitorizacion ambiental. Y en esta necesidad de seguir identificándolos y cuantificándolos se encuentra, en un punto destacado, su potencial efecto como disruptores endocrinos, tema de suma importancia desde el punto de vista de la reproducción de las especies de vida salvaje. De hecho, en las dos últimas décadas, se ha incrementado entre la comunidad científica el interés por investigar las posibles alteraciones en el funcionamiento del sistema endocrino de vertebrados e invertebrados como consecuencia de la exposición a productos químicos. En definitiva, la presente revisión resume los conocimientos más actualizados existentes sobre los Bifenilos policlorados cuantificados en la fauna salvaje, y sus principales efectos sobre la reproducción.
Cambios y transformaciones urbanas en Zaragoza, tras la “Expo” del 2008
Authors: Sotelo Pérez María , Sotelo Navalpotro José Antonio
Published: December 2016

La Exposición Internacional de Zaragoza celebrada en el año 2008, bajo el lema Agua y Desarrollo Sostenible, fue un acontecimiento que favoreció la puesta en valor de una ciudad con gran potencial, permitiendo generar un crecimiento sustancial, tanto económico como social, en la capital autónoma y en el conjunto de la Comunidad de Aragón. En el presente artículo nos aproximamos a esa realidad de cambio en los modelos de crecimiento y desarrollo urbano que experimentó la ciudad de Zaragoza tras la celebración de la Exposición Internacional, analizando las transformaciones experimentadas tanto en su medio físico como humano, natural y económico, surgidos a partir de la ingente movilización de recursos, mediante los cuales se mejoraron las infraestructuras de la ciudad - tanto en el propio recinto como en sus áreas de influencia y entorno más próximo-, impulsando así nuevos proyectos urbanísticos e implementando buenas prácticas en materia ambiental-, fundamentalmente, en gestión y conservación del agua y el desarrollo sostenible.
Employing Phenology to Delineate Wheat Agro-Climatic Zones in Afghanistan
Authors: Obaidi M. Q. , Mohmand Elias , Azmatyar M. H. , Sharma Rajiv
Published: December 2016

Afghanistan grows wheat on about 2.5 million hectares with an average annual production of about five million tonnes. The local research and development efforts make use of country wide research results to recommend varieties and other technologies. Afghanistan has wide ranging climatic variability and its wheat acreage therefore needs to be delineated into wheat climatic zones. A set of 10 different types of wheat varieties were scored for average number of days to 50% flowering (ADF) at 10 locations to delineate Afghan wheat acreage into homogeneous wheat climatic zones based on ADF values. The results obtained hinted at creating eastern, northern, south western and a highland zone for conducting research and recommending wheat technologies.
Urea Fertilizer Placement Impacts on Corn Growth and Nitrogen Utilization in a Poorly-Drained Claypan Soil
Authors: Johnson II Frank E. , Nelson Kelly A. , Motavalli Peter P.
Published: December 2016

Practices to increase nitrogen (N) use efficiency (NUE) include selecting appropriate N fertilizer sources and application methods, but minimal research has focused on these practices in poorly-drained claypan soils which are prone to N loss. This research assessed the impact of different urea fertilizer placement practices on corn (Zea mays L.) production and N utilization in a poorly-drained claypan soil. Field trials were conducted in 2014 and 2015 in Missouri. Treatments consisted of pre-plant deep banding (20 cm) urea at 202 kg N ha-1 or urea plus a nitrification inhibitor (NI) (nitrapyrin) compared to pre-plant urea broadcast surface-applied or incorporated to a depth of 8 cm. In 2014, incorporating urea, deep banding urea, and deep banding urea plus NI had higher yields (> 10%) of corn compared to the control with grain yields ranging from 13.73 to 14.05 Mg ha-1. In 2015, grain yields were lower than in 2014, ranging from 4.1 to 7.9 Mg ha-1. Deep placing banded urea with a NI yielded an increase in grain yield up to 48% compared to the other treatments. Rainfall amounts were higher in 2015, which could have resulted in poorer root growth and greater N loss in deep banded treatments. In 2014, deep banding urea with a NI produced the highest NUE. Similar to NUE, silage tissue N concentrations in 2014 were greater with deep banded urea plus NI, while in 2015 silage tissue N concentrations were higher with surface applied urea. The results suggest that urea fertilizer incorporation including deep banding may improve corn grain production, N uptake, and NUE, but response was affected by climatic conditions. The addition of an NI may be an important safeguard when deep banding urea in years with excessive precipitation.
Determination of Biotin in Infant, Pediatric, and Adult Nutritionals by High-Performance Liquid Chromatography and Fluorescence Detection: Single-Laboratory Validation, First Action 2016.11
Authors: Lin Qi , Ding Yi , Poh Fiona , Zhang Chunyan , Pan Shang-Jing , Schimpf Karen J
Published: December 2016

A reversed-phase HPLC method with postcolumn protein conjugation and fluorescence detection for the quantitative determination of biotin in infant, pediatric, and adult nutritionals was developed and evaluated in a single-laboratory validation (SLV). Sample of appropriate size is mixed with 2% metaphosphoric acid to precipitate out the protein. The filtrate is injected onto a C18 HPLC column in which biotin and riboflavin are separated with an appropriate mobile phase. The biotin, after eluting from the column, binds with the streptavidin fluorescein to become a fluorescent conjugate. The conjugate is then detected by fluorescence at λex = 495 nm and λem = 518 nm. A column switch is used in the method as an option to shorten the run time from 30 to 15 min, by eluting out riboflavin at a higher flow rate. In this SLV, a total of 19 AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals matrixes representing a range of infant,pediatric, and adult formulas were evaluated for their biotin content. The analytical range was 1.66–142 μg/100 g reconstituted final product. The repeatability and intermediate precision ranged from 0.5 to 3.0% RSDr and from 1.3 to 4.5% RSDiR, respectively. Recovery from spiked matrixes varied from 95 to 111%, and accuracy of quantification using Standard Reference Material 1849a ranged from 99 to 105%. The LOQ in reconstituted product was estimated to be 0.8 μg/100 g. The method was approved by the Expert Review Panel as First Action at the 2016 AOAC INTERNATIONAL Mid-Year Meeting.
Itinerários de Minas: representação espacial e visão corográfica na obra de Raimundo José da Cunha Matos
Authors: Castro Pérola Maria Goldfeder e
Published: December 2016

Este artigo trata das representações espaciais do Império brasileiro feitas sob a perspectiva do olhar corográfico. Por meio da análise de algumas obras de Raimundo José da Cunha Matos, militar expedicionário que descreveu as paisagens de Minas Gerais entre os anos 1830 e 1850, buscamos analisar como diferentes transformações no mosaico imperial influíram na maneira de se enxergar o território e distinguir suas partes. Ao final dessa exposição, a ideia principal que se esboça é a de que conhecimento sobre o território é, indissociavelmente, produção dele mesmo.
A região como artefato: o Cariri na segunda metade dos Oitocentos
Authors: Reis Junior Darlan De Oliveira
Published: December 2016

Na segunda metade do século XIX, a região conhecida por Cariri cearense, localizada no extremo sul da província do Ceará, destacava-se no sertão por ser conhecida como um “oásis” no semiárido, devido a sua vegetação, a presença de fontes d’água e solos férteis. Elaborou-se um discurso sobre a região ser o “celeiro” dos sertões. O presente artigo busca entender como, no espaço regional, o discurso sobre a natureza serviu de recurso político para o desenvolvimento da ideia de progresso por intermédio do trabalho que, no contexto histórico delimitado na temporalidade, refletia-se na submissão de trabalhadores livres em diversas condições econômicas e trabalhadores escravizados. Pretende-se analisar como as diferentes classes sociais estabeleceram suas identidades e vivências na região, as contradições resultantes da desigualdade social, bem como as práticas de controle estabelecidas pelos senhores e as diferentes formas de resistência dos trabalhadores.
Utilização do MPS-BR para análise do processo de desenvolvimento de software em startups
Authors: Silva Jansser Dias , Miranda Junior Pateur Ottoni de
Published: December 2016

O cenário tecnológico e econômico propiciado pelas startups de base tecnológica mostra-se promissor e ao mesmo tempo preocupante. Este artigo baseia-se nos principais motivos atribuídos ao fracasso de 101 startups de acordo com os seus fundadores e compara essas razões ao idealizado pelas boas práticas de Engenharia de Software. É mostrado que falhas presentes, principalmente, na realização dos processos de Gerência de Requisitos e Gerência de Projetos levam cerca de 90% dessas organizações à falência. Com isso, o guia MPS-BR foi utilizado como referência para analisar e atribuir um índice de adequação ao processo de desenvolvimento de software em quatro projetos de três startups. Por fim, foi atribuído a cada projeto um índice de aderência quantitativo de acordo com as práticas e resultados evidenciados nos processos analisados. Esses resultados foram disponibilizados às organizações para auxiliá-las a estabelecerem condições de sucesso para seus projetos.
Proposta de um Algoritmo Híbrido baseado em Colônia de Formigas para o Problema de Roteamento de Veículos com Restrições de Cobertura
Authors: Souza Vitor A A , Lopes Ramon , Januario Tiago
Published: December 2016

O Problema de Roteamento de Veículos (PRV) é um problema clássico de Otimização Combinatória, e a principal motivação para o seu estudo e de suas variações é o alto gasto com o transporte de cargas, impactando nos preços da matéria prima e do produto final. Neste trabalho, estuda-se uma variação do PRV denominada Problema de Cobertura Multi- Veículo (PCMV) que, diferentemente das demais variações existentes na literatura, possui restrições de cobertura e natureza seletiva, além das restrições de carga nos veículos. Este trabalho propõe um algoritmo híbrido baseado em Colônia de Formigas (CF) para o PCMV que utiliza um algoritmo Variable Neighborhood Search (VNS) e fundamenta-se na trans- formação do PCMV em um Problema de Roteamento de Veículos Capacitado (PRVC), para o qual o método apresentado foi projetado. O algoritmo proposto obteve 16 novos limites primais para as 30 Instâncias consideradas em um tempo computacional inferior a 21 segundos, enquanto os resultados apresentados na literatura foram encontrados em até quatro horas de execução. 
Gauging Music Vitality and Viability: Three Cases from Cambodia
Authors: Grant Catherine , Sarin Chhuon
Published: December 2016

Over a decade ago, UNESCO's Convention for the Safeguarding of Intangible Cultural Heritage professed that “the processes of globalization and social transformation” along with “the phenomenon of intolerance” were giving rise to “grave threats of deterioration, disappearance and destruction of the intangible cultural heritage” of the world (2003a). The Convention represented an international acknowledgement of the precarious predicament of many cultural expressions across the world, from languages, music, and dance traditions to worldviews and traditional environmental knowledge. While ethnomusicologists have been engaging for many decades with preservation and protection mechanisms for musical traditions, particularly those of ethnic and minority peoples, the 2003 Convention (and the suite of subsequent UNESCO and UN treaties around culture and heritage) provided further impetus for ethnomusicological engagement in safeguarding and sustainability work. Theoretical and applied research in this area has grown significantly in the last ten to fifteen years on topics ranging from music and tourism (e.g., Connell and Gibson 2005), music as heritage (e.g., Howard 2006), music and cultural rights (e.g., Weintraub and Yung 2009), and music revivals (e.g., Bithell and Hill 2014), to activist or community-oriented approaches to music sustainability (e.g., Pettan and Titon 2015; Schippers and Grant 2016).
Le Congrès juif canadien et l’hostilité à l’immigration juive dans l’immédiat après-guerre (1945-1948)1
Authors: Burgard Antoine
Published: December 2016

La politique migratoire canadienne des années 1930 et 1940 est la plus restrictive et sélective de l’histoire du pays, notamment en raison de son hostilité envers les populations migrantes juives. La question de l’antisémitisme au Canada et au Québec ne peut donc se poser sans revenir sur la position d’Ottawa en matière migratoire. Dans cet article, nous souhaitons examiner non pas les manifestations de cette hostilité, mais la manière dont celle-ci fut perçue et combattue par le Congrès juif canadien (CJC), alors principale organisation de la communauté, entre 1945 et 1948. En effet, quelle image le CJC a-t-il vraiment de l’hostilité de l’opinion publique et des mécanismes discriminatoires de la politique migratoire canadienne ? Et comment cette perception façonne-t-elle durablement sa stratégie de lutte contre l’antisémitisme et l’hostilité à l’immigration juive ainsi que ses rapports avec le gouvernement King ? L’analyse fine du travail des principaux cadres du CJC sur cette question permet de jeter un éclairage nouveau sur la place de l’organisation au sein du judaïsme canadien, de mieux cerner ses relations avec la presse et, surtout, ses rapports avec un gouvernement et une administration pour le moins hostiles à l’entrée de migrants juifs au Canada.
The Opaque Nature of John Constable’s Naturalism
Authors: Wien Iris
Published: December 2016

Situant les dessins de Constable dans un contexte épistémologique post-Berkleyien, cet article suggère que le basculement vers une structure représentationnelle, qui met l’accent sur l’écart entre les fonctions figuratives et picturales, avait été nécessaire pour assurer la prétention à la vérité du naturalisme de l’artiste. Nous soutenons que les modulations réalistes dans la conceptualisation sémiotique de Berkeley de la perception visuelle furent instrumentales à une esthétique qui s’efforçait d’enligner le langage de la nature avec le sentiment, réconciliant ainsi l’expression subjective et les demandes de l’objectivité. Pourtant, ainsi que nous le démontrons, la rupture d’un ordre de représentation « transparent » qu’opéra Constable eut des implications non seulement scientifiques, mais également idéologiques.
The Struggle Against Naturalism: Soviet Art from the 1920s to the 1950s
Authors: Silina Maria
Published: December 2016

En 1936, en Union soviétique, des critiques anonymes lancèrent une campagne répressive « contre le naturalisme et le formalisme ». Il devint alors impossible, pour plusieurs artistes, d’exposer leur travail et de participer à des concours artistiques. Les artistes « formalistes », tels le suprématiste Kasimir Malevitch et le réaliste analytique Pavel Filonov, étaient facilement identifiables, car ils étaient représentatifs du modernisme européen. La définition du naturalisme, par contre, était beaucoup moins précise. Perçu comme une reproduction presque photographique de la réalité, le naturalisme était pratiqué par les membres de l’Association des artistes de la Russie révolutionnaire. Dans cet article, nous étudions l’histoire de la notion de naturalisme en Union soviétique durant les années 1920–1950 et démontrons son importance pour la définition du réalisme socialiste.
Effect of UV-light illumination on oxide-based electric-double-layer thin-film transistors
Authors: Zhou Jumei , Hu Yunping
Published: December 2016

Indium–tin-oxide (ITO)-based thin-film transistors (TFTs) were fabricated using porous SiO2 deposited by plasma-enhanced chemical vapor deposition and Al2O3 deposited by atomic layer deposition as dielectrics. The results showed that the porous SiO2 film exhibited a high electric-double-layer (EDL) capacitance. Devices gated by the EDL dielectric exhibited a high drain current on/off ratio of >106 and a low operation voltage of <2.0 V in the dark. When illuminated by 254 nm UV light, ITO-based EDL TFTs gated by a single SiO2 dielectric displayed weak photo-responses. However, devices gated by a stacked Al2O3/EDL dielectric displayed a high photo responsivity of more than 104 with a gate bias of −0.5 V (depletion state).
Fabrication of four-path remote outdoor wind velocity measurement system and its performance evaluation
Authors: Yamada Akira , Oba Kensyo , Shimizu Masato
Published: December 2016

A method is proposed for the remote measurement of the outdoor ground-surface two-dimensional (2D) vector wind velocity field averaged over a region of 10–50 m size. To this end, four-channel (4ch) sound wave transmitters and receivers were placed at the corners of a rectangular monitoring site. From the four-path travel time data, the wind velocity and direction averaged over the region were estimated under the uniform-wind-field assumption. By this method, misestimation due to the local turbulence wind field, which is encountered in conventional in situ-type anemometers, can be avoided. To achieve a satisfying speed data collection that keeps up with the rapid changes in real wind field, coded modulation signals were transmitted and received simultaneously between all the 4ch speaker/microphone pairs. Test experiments demonstrated that time variations of vector wind velocities spatially averaged over the area were successively measured with satisfying speed and accuracy.
Evaluating the potential of the GFAP‐KLH immune‐tolerizing vaccine for type 1 diabetes in mice
Authors: Pang Zhengda , Higuchi Masayoshi , Koriyama Hiroshi , Yoshida Shota , Kurinami Hitomi , Shimamura Munehisa , Takami Yoichi , Rakugi Hiromi , Morishita Ryuichi , Nakagami Hironori
Published: December 2016

Glial fibrillary acidic protein (GFAP), expressed in peri‐islet Schwann cells, is a novel target for the treatment of type 1 diabetes mellitus (T1DM). We designed a GFAP immune‐tolerizing vaccine that successfully suppresses hyperglycemia and enhances C peptide secretion. The GFAP vaccine significantly prevented T cell infiltration into pancreatic islets. Moreover, after GFAP vaccination, naïve T‐cell differentiation shifted from a cytotoxic Th1‐ to a Th2‐biased humoral response. These results indicate that as a novel target, GFAP reliably predicts the development of T1DM, and that the GFAP vaccine successfully delays the progression of T1DM by regulating T‐cell differentiation.
Identification of proximal sites for unwound DNA substrate in Escherichia coli topoisomerase I with oxidative crosslinking
Authors: Cheng Bokun , Zhou Qingxuan , Weng Liwei , Leszyk John D. , Greenberg Marc M. , Tse‐Dinh Yuk‐Ching
Published: December 2016

Topoisomerases catalyze changes in DNA topology by directing the movement of DNA strands through consecutive cleavage‐rejoining reactions of the DNA backbone. We describe the use of a phenylselenyl‐modified thymidine incorporated into a specific position of a partially unwound DNA substrate in crosslinking studies of Escherichia coli topoisomerase I to gain new insights into its catalytic mechanism. Crosslinking of the phenylselenyl‐modified thymidine to the topoisomerase protein was achieved by the addition of a mild oxidant. Following nuclease and trypsin digestion, lysine residues on topoisomerase I crosslinked to the modified thymidine were identified by mass spectrometry. The crosslinked sites may correspond to proximal sites for the unwound DNA strand as it interacts with enzyme in the different stages of the catalytic cycle.
Investigating the roles of T224 and T232 in the oxidation of cinnamaldehyde catalyzed by myxobacterial CYP260B1
Authors: Litzenburger Martin , Lo Izzo Roberta , Bernhardt Rita , Khatri Yogan
Published: December 2016

Although the oxidation of aldehydes to carboxylic acids is mainly catalyzed by aldehyde dehydrogenases in nature, cytochromes P450 are also able to perform such reactions. In this study, we demonstrate the oxidation of cinnamaldehyde to cinnamic acid by the myxobacterial CYP260B1. Following our docking studies of the aldehyde, we generated T224A and T234A mutants of CYP260B1 by site‐directed mutagenesis to disrupt the substrate positioning and proton delivery, respectively. Furthermore, we used the kinetic solvent isotope effect on the steady‐state turnover of the substrate to investigate the reactive intermediate capable of performing the catalysis. Our results suggest that the aldehyde oxidation occurs via a nucleophilic attack of the ferric peroxoanion.
The F‐box protein FBXL18 promotes glioma progression by promoting K63‐linked ubiquitination of Akt
Authors: Zhang Jindong , Yang Zhifen , Ou Jiayu , Xia Xiaojun , Zhi Feng , Cui Jun
Published: December 2016

F‐box proteins play pivotal roles in multiple cellular processes; however, little is known about their functions in glioma progression. In this study, we found that expression of the F‐box and leucine‐rich repeat protein 18 (FBXL18) is significantly upregulated in glioma tissues. Depletion of FBXL18 in glioma cells suppresses proliferation and anchorage‐independent cell growth, and promotes apoptosis. We also demonstrate that depletion of FBXL18 significantly inhibits Akt activity and the phosphorylation of FOXO3a, which leads to upregulation of BCL2L11. Further mechanistic analyses indicate that FBXL18 promotes the K63‐linked ubiquitination of Akt, which is required for its activation. Taken together, our results suggest that FBXL18 plays an oncogenic role through promoting K63‐linked ubiquitination of Akt in glioma.
Enhancement of oxygen in the magnetic island associated with dipolarization fronts
Authors: Wang J. , Cao J. B. , Fu H. S. , Liu W. L. , Lu S.
Published: December 2016

A significant enhancement of O+ is observed by Cluster inside an earthward propagating magnetic island behind a dipolarization front (DF). Such enhancement, from 0.005 to 0.03 cm−3, makes the O+ flux inside the magnetic island ~20 times larger than that outside the magnetic island. In the meantime, the H+ density is nearly a constant, 0.1 cm−3, during the magnetic‐island encounter. This results in a dramatic increase of the density ratio,
, from 0.05 to 0.3 (about 10 times as large as the average value in the plasma sheet) and a dramatic decrease of the local Alfvén speed from VA ≈ 770 km/s to VA ≈ 430 km/s inside the magnetic island. The decrease of Alfvén speed indicates an asymmetric reconnection and a slow magnetic reconnection rate near the secondary X line. Since the reconnection rates at the primary X line and secondary X line are imbalanced, the DFs and magnetic islands are pushed to propagate earthward by the outflow of the primary reconnection, as demonstrated in recent simulations.
Electron holes in the outer radiation belt: Characteristics and their role in electron energization
Authors: Vasko I. Y. , Agapitov O. V. , Mozer F. S. , Artemyev A. V. , Drake J. F. , Kuzichev I. V.
Published: December 2016

Van Allen Probes have detected electron holes (EHs) around injection fronts in the outer radiation belt. Presumably generated near equator, EHs propagate to higher latitudes potentially resulting in energization of electrons trapped within EHs. This process has been recently shown to provide electrons with energies up to several tens of keV and requires EH propagation up to rather high latitudes. We have analyzed more than 100 EHs observed around a particular injection to determine their kinetic structure and potential energy sources supporting the energization of trapped electrons. EHs propagate with velocities from 1000 to 20,000 km/s (a few times larger than the thermal velocity of the coldest background electron population). The parallel scale of observed EHs is from 0.3 to 3 km that is of the order of hundred Debye lengths. The perpendicular to parallel scale ratio is larger than one in a qualitative agreement with the theoretical scaling relation. The amplitudes of EH electrostatic potentials are generally below 100 V. We determine the properties of the electron population trapped within EHs by making use of the Bernstein‐Green‐Kruskal analysis and via analysis of EH magnetic field signatures. The density of the trapped electron population is on average 20% of the background electron density. The perpendicular temperature of the trapped population is on average 300 eV and is larger for faster EHs. We show that energy losses of untrapped electrons scattered by EHs in the inhomogeneous background magnetic field may balance the energization of trapped electrons.
In situ statistical observations of Pc1 pearl pulsations and unstructured EMIC waves by the Van Allen Probes
Authors: Paulson K. W. , Smith C. W. , Lessard M. R. , Torbert R. B. , Kletzing C. A. , Wygant J. R.
Published: December 2016

We present here the first in situ statistical survey of structured Pc1 pearl pulsations compared with unstructured electromagnetic ion cyclotron (EMIC) waves observed by the Van Allen Probes spacecraft. This data set was compiled from observations spanning 8 September 2012 through 31 August 2015 and comprises over 1630 h of total EMIC wave activity, of which 291 h exhibited pearl structure. Additionally, we have identified 29 wave events demonstrating periodically oscillating wave packets, mostly about the magnetic equator, indicated by the reversal of Poynting flux along the background magnetic field. We have found several stark differences between Pc1 pearl pulsations and unstructured EMIC waves. While unstructured EMIC waves demonstrate the predicted behavior of a higher occurrence across the dayside with enhanced wave power at dusk, pearl pulsations occur uniformly across magnetic local time, with a small enhancement in the late morning sector. Pearl pulsations were more often observed during magnetospherically quiet periods, particularly in the late recovery period of geomagnetic storms. The mean excitation frequency of pearl pulsations was observed to be independent of the local ion cyclotron frequency, and individual wave investigations indicate that the modulation period also remained constant for the duration of the event over a finite range in L. We examine three possible generation mechanisms—the bouncing wave packet model, modulation by ultralow‐frequency Pc4 and Pc5 waves, and the formation of an ion cyclotron resonator—but are unable to definitively confirm the validity of any one model.
Reply to comment by Remya et al. on “Effects of electron temperature anisotropy on proton mirror instability evolution”
Authors: Ahmadi Narges , Germaschewski Kai , Raeder Joachim
Published: December 2016

In the comment to our paper, Remya et al. (2017) state that we conclude that their theory is incorrect; however, no such conclusion is in our paper. In fact, as stated in their paper, we agree with their theory that shows the impact of heavy ions and electron temperature anisotropy on the competition of the ion anisotropy instabilities. While their linear theory is correct, our paper focused on the nonlinear evolution, where one needs to be careful in assuming a given electron anisotropy, because electrons themselves can be unstable to the electron whistler instability, which quickly lowers the anisotropy to levels where, in the absence of heavy ions, it is not sufficient to significantly change the balance between proton cyclotron and mirror mode. We agree that the electron whistler instability will not lead to complete isotropization of the electrons but only lower it to the instability threshold. In the parameter regime addressed, this limited isotropization will still eliminate the dominance of mirror mode and restore the usual dominance of the proton cyclotron mode, so our point still stands. Our simulations showed an isotropization of the electrons beyond the electron whistler threshold. In this reply, we will show that there are two contributing reasons: The nonlinear evolution of the mirror instability affects the electron anisotropy, as does unphysical numerical heating due to the limited resolution of a particle‐in‐cell simulation. We further discuss the coexistence of electron whistler instability and mirror instability, and we agree that both instabilities can be present in the magnetosheath.
Impact of Asian aerosol forcing on tropical Pacific circulation and the relationship to global temperature trends
Authors: Kuntz L. B. , Schrag D. P.
Published: December 2016

The recent slowdown in the warming of global surface temperatures has been linked to the enhancement of trade winds in the central equatorial Pacific. The possible role of Asian aerosol emissions in forcing these wind anomalies is investigated through a series of idealized model simulations. Circulation patterns in response to localized negative radiative perturbations, indicative of aerosol effects, are investigated for both a slab and an active ocean models. The results suggest that Asian aerosols cannot explain the recent intensification of trade wind anomalies in the equatorial Pacific.
Comprehensive assessment of PM2.5 physicochemical properties during the Southeast Asia dry season (southwest monsoon)
Authors: Khan Md Firoz , Sulong Nor Azura , Latif Mohd Talib , Nadzir Mohd Shahrul Mohd , Amil Norhaniza , Hussain Dini Fajrina Mohd , Lee Vernon , Hosaini Puteri Nurafidah , Shaharom Suhana , Yusoff Nur Amira Yasmin Mohd , Hoque Hossain Mohammed Syedul , Chung Jing Xiang , Sahani Mazrura , Mohd Tahir Norhayati , Juneng Liew , Maulud Khairul Nizam Abdul , Abdullah Sharifah Mastura Syed , Fujii Yusuke , Tohno Susumu , Mizohata Akira
Published: December 2016

A comprehensive assessment of fine particulate matter (PM2.5) compositions during the Southeast Asia dry season is presented. Samples of PM2.5 were collected between 24 June and 14 September 2014 using a high‐volume sampler. Water‐soluble ions, trace species, rare earth elements, and a range of elemental carbon (EC) and organic carbon were analyzed. The characterization and source apportionment of PM2.5 were investigated. The results showed that the 24 h PM2.5 concentration ranged from 6.64 to 68.2 µg m−3. Meteorological driving factors strongly governed the diurnal concentration of aerosol, while the traffic in the morning and evening rush hours coincided with higher levels of CO and NO2. The correlation analysis for non sea‐salt K+‐EC showed that EC is potentially associated with biomass burning events, while the formation of secondary organic carbon had a moderate association with motor vehicle emissions. Positive matrix factorization (PMF) version 5.0 identified the sources of PM2.5: (i) biomass burning coupled with sea salt [I] (7%), (ii) aged sea salt and mixed industrial emissions (5%), (iii) road dust and fuel oil combustion (7%), (iv) coal‐fired combustion (25%), (v) mineral dust (8%), (vi) secondary inorganic aerosol (SIA) coupled with F− (15%), and (vii) motor vehicle emissions coupled with sea salt [II] (24%). Motor vehicle emissions, SIA, and coal‐fired power plant are the predominant sources contributing to PM2.5. The response of the potential source contribution function and Hybrid Single‐Particle Lagrangian Integrated Trajectory backward trajectory model suggest that the outline of source regions were consistent to the sources by PMF 5.0.
Further evidence for early lunar magnetism from troctolite 76535
Authors: Garrick‐Bethell Ian , Weiss Benjamin P. , Shuster David L. , Tikoo Sonia M. , Tremblay Marissa M.
Published: December 2016

The earliest history of the lunar dynamo is largely unknown and has important implications for the thermal state of the Moon and the physics of dynamo generation. The lunar sample with the oldest known paleomagnetic record is the 4.25 billion year old (Ga) troctolite 76535. Previous studies of unoriented subsamples of 76535 found evidence for a dynamo field with a paleointensity of several tens of microteslas. However, the lack of mutual subsample orientation prevented a demonstration that the magnetization was unidirectional, a key property of thermoremanent magnetization. Here we report further alternating field demagnetization on three mutually oriented subsamples of 76535, as well as new pressure remanent magnetization experiments to help rule out shock magnetization. We also describe new 40Ar/39Ar thermochronometry and cosmogenic neon measurements that better constrain the rock's thermal history. Although the rock is unbrecciated, unshocked, and slowly cooled, its demagnetization behavior is not ideal due to spurious remanence acquisition. Despite this limitation, all three subsamples record a high coercivity magnetization oriented in nearly the same direction, implying that they were magnetized by a unidirectional field on the Moon. We find no evidence for shock remanence, and our thermochronometry calculations show no significant reheating events since 4249 ± 12 million years ago (Ma). We infer a field paleointensity of approximately 20–40 μT, supporting the previous conclusion that a lunar dynamo existed at 4.25 Ga. The timing of this field supports an early dynamo powered by thermal or thermochemical core convection and/or a mechanical dynamo but marginally excludes a dynamo delayed by thermal blanketing from radiogenic element‐rich magma ocean cumulates.
Applicability of the ecosystem type approach to model permafrost dynamics across the Alaska North Slope
Authors: Nicolsky D. J. , Romanovsky V. E. , Panda S. K. , Marchenko S. S. , Muskett R. R
Published: December 2016

Thawing and freezing of Arctic soils is affected by many factors, with air temperature, vegetation, snow accumulation, and soil physical properties and soil moisture among the most important. We enhance the Geophysical Institute Permafrost Laboratory model and develop several high spatial resolution scenarios of changes in permafrost characteristics in the Alaskan Arctic in response to observed and projected climate change. The ground thermal properties of surface vegetation and soil column are upscaled using the Ecosystems of Northern Alaska map and temperature data assimilation from the shallow boreholes across the Alaska North Slope. Soil temperature dynamics are simulated by solving the 1‐D nonlinear heat equation with phase change, while the snow temperature and thickness are simulated by considering the snow accumulation, compaction, and melting processes. The model is verified by comparing with available active layer thickness at the Circumpolar Active Layer Monitoring sites, permafrost temperature, and snow depth records from existing permafrost observatories in the North Slope region.
Highly efficient removal of bulky tannic acid by millimeter‐sized nitrogen‐doped mesoporous carbon beads
Authors: Chong Yanping , Liu Ke , Liu Yu , Wang Jitong , Qiao Wenming , Ling Licheng , Long Donghui , Bai Zhishan
Published: December 2016

Millimeter‐sized nitrogen‐doped mesoporous carbon beads (NMCBs) with a controllable nitrogen content are synthesized for the first time via a suspension‐polymerization assisted hard templating method. In contrast to conventional activated carbons, NMCBs exhibit outstanding structural advantages, including macroscopic morphology, a developed mesoporous structure and enriched surface chemistry. When used as adsorbents for the removal of the bulky organic pollutant tannic acid, these NMCBs demonstrated fast adsorption kinetics and very high adsorption capacity. The adsorption capacity strongly depends on the nitrogen content doped into the carbon framework. At a nitrogen content of 4.1 wt %, the adsorption capacity reaches 318 mg g−1. The molecular mechanics simulation and zeta potential measurements suggest that the enhanced adsorption by nitrogen doping may be due to the electrostatic attraction between the nitrogen functional groups and the phenol groups of tannic acid. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3016–3025, 2017
Game theory approach to optimal design of shale gas supply chains with consideration of economics and life cycle greenhouse gas emissions
Authors: Gao Jiyao , You Fengqi
Published: December 2016

This article addresses the optimal design of a non‐cooperative shale gas supply chain based on a game theory approach. Instead of assuming a single stakeholder as in centralized models, we consider different stakeholders, including the upstream shale gas producer and the midstream shale gas processor. Following the Stackelberg game, the shale gas producer is identified as the leader, whose objectives include maximizing its net present value (NPV) and minimizing the life cycle greenhouse gas (GHG) emissions. The shale gas processor is identified as the follower that takes actions after the leader to maximize its own NPV. The resulting problem is a multiobjective mixed‐integer bilevel linear programming problem, which cannot be solved directly using any off‐the‐shelf optimization solvers. Therefore, an efficient projection‐based reformulation and decomposition algorithm is further presented. Based on a case study of the Marcellus shale play, the non‐cooperative model not only captures the interactions between stakeholders but also provides more realistic solutions. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2671–2693, 2017
Recent Advances in the Intramolecular Reactions of Epoxides with Arenes and Heteroarenes
Authors: Das Sajal Kumar
Published: December 2016

Over the years, the reactions and applications of epoxides have attracted the attention of many research groups. Intramolecular reactions of epoxides with arenes, termed epoxide–arene cyclizations (EACs) in this Focus Review, are the intramolecular C−C bond‐forming reactions of arenes with tethered epoxides and represent a particular type of epoxide‐derivatization reactions. EACs have been successfully applied to the synthesis of various benzo‐fused carbo‐ and heterocycles as reliable C−C bond‐forming reactions with complete atom economy. In this Focus Review, results in the literature since 2011 on the development of EACs are presented. Different aspects of substrate reactivities, the regio‐ and stereochemical outcomes of these reactions, and their proposed mechanisms are discussed.