bluuebunny/crossref_metadata_2025 huggingface dataset:
Metrology of ground-based satellite validation: co-location mismatch and smoothing issues of total ozone comparisons
Authors: Verhoelst T. , Granville J. , Hendrick F. , Köhler U. , Lerot C. , Pommereau J.-P. , Redondas A. , Van Roozendael M. , Lambert J.-C.
Published: August 2015

Abstract. Comparisons with ground-based correlative measurements constitute a key component in the validation of satellite data on atmospheric composition. The error budget of these comparisons contains not only the measurement uncertainties but also several terms related to differences in sampling and smoothing of the inhomogeneous and variable atmospheric field. A versatile system for Observing System Simulation Experiments (OSSEs), named OSSSMOSE, is used here to quantify these terms. Based on the application of pragmatic observation operators onto high-resolution atmospheric fields, it allows a simulation of each individual measurement, and consequently also of the differences to be expected from spatial and temporal field variations between both measurements making up a comparison pair. As a topical case study, the system is used to evaluate the error budget of total ozone column (TOC) comparisons between on the one hand GOME-type direct fitting (GODFITv3) satellite retrievals from GOME/ERS2, SCIAMACHY/Envisat, and GOME-2/MetOp-A, and on the other hand direct-sun and zenith-sky reference measurements such as from Dobsons, Brewers, and zenith scattered light (ZSL-)DOAS instruments respectively. In particular, the focus is placed on the GODFITv3 reprocessed GOME-2A data record vs. the ground-based instruments contributing to the Network for the Detection of Atmospheric Composition Change (NDACC). The simulations are found to reproduce the actual measurements almost to within the measurement uncertainties, confirming that the OSSE approach and its technical implementation are appropriate. This work reveals that many features of the comparison spread and median difference can be understood as due to metrological differences, even when using strict co-location criteria. In particular, sampling difference errors exceed measurement uncertainties regularly at most mid- and high-latitude stations, with values up to 10 % and more in extreme cases. Smoothing difference errors only play a role in the comparisons with ZSL-DOAS instruments at high latitudes, especially in the presence of a polar vortex. At tropical latitudes, where TOC variability is lower, both types of errors remain below about 1 % and consequently do not contribute significantly to the comparison error budget. The detailed analysis of the comparison results, including now the metrological errors, suggests that the published random measurement uncertainties for GODFITv3 reprocessed satellite data are potentially overestimated, and adjustments are proposed here. This successful application of the OSSSMOSE sytem to close for the first time the error budget of TOC comparisons, bodes well for potential future applications, which are briefly touched upon.
Metagenomic analyses of the late Pleistocene permafrost – additional tools for reconstruction of environmental conditions
Authors: Rivkina E. , Petrovskaya L. , Vishnivetskaya T. , Krivushin K. , Shmakova L. , Tutukina M. , Meyers A. , Kondrashov F.
Published: August 2015

Abstract. A comparative analysis of the metagenomes from two 30 000 year-old permafrost samples, one of lake-alluvial origin and the other from late Pleistocene Ice Complex sediments, revealed significant differences within microbial communities. The late Pleistocene Ice Complex sediments (which have been characterized by the absence of methane with lower values of redox-potential and Fe2+ content) showed both a low abundance of methanogenic archaea and enzymes from the carbon, nitrogen and sulfur cycles. The metagenomic and geochemical analyses described in the paper provide evidence that the formation of the late Pleistocene Ice Complex sediments likely took place under much more aerobic conditions than lake-alluvial sediments.
Phototrophic pigment diversity and picophytoplankton abundance in permafrost thaw lakes
Authors: Przytulska A. , Comte J. , Crevecoeur S. , Lovejoy C. , Laurion I. , Vincent W. F.
Published: August 2015

Abstract. Permafrost thaw lakes (thermokarst lakes) are widely distributed across the northern landscape, and are known to be biogeochemically active sites that emit large amounts of carbon to the atmosphere as CH4 and CO2. However, the abundance and composition of the photosynthetic communities that consume CO2 have been little explored in this ecosystem type. In order to identify the major groups of phototrophic organisms and their controlling variables, we sampled 12 permafrost thaw lakes along a permafrost degradation gradient in northern Québec, Canada. Additional samples were taken from 5 rock-basin reference lakes in the region to determine if the thaw waters differed in limnological properties and phototrophs. Phytoplankton community structure was determined by high performance liquid chromatography analysis of their photoprotective and photosynthetic pigments, and autotrophic picoplankton concentrations were assessed by flow cytometry. One of the black colored lakes located in a andscape of rapidly degrading palsas (permafrost mounds) was selected for high-throughput 18S rRNA sequencing to help interpret the pigment and cytometry data. The results showed that the limnological properties of the thaw lakes differed significantly from the reference lakes, and were more highly stratified. However, both waterbody types contained similarly diverse phytoplankton groups, with dominance of the pigment assemblages by fucoxanthin-containing taxa, as well as chlorophytes, cryptophytes and cyanobacteria. Chlorophyll a concentrations (Chl a) were correlated with total phosphorus (TP), and both were significantly higher in the thaw lakes (overall means of 3.3 μg Chl a L−1 and 34 μg TP L−1) relative to the reference lakes (2.0 μg Chl a L−1 and 8.2 μg TP L−1). Stepwise multiple regression of Chl a against the other algal pigments showed that it was largely a function of lutein, fucoxanthin and peridinin (R2 = 0.78). The bottom waters of two of the thaw lakes also contained high concentrations of bacteriochlorophyll d, showing the presence of green photosynthetic sulphur bacteria. The molecular analyses indicated a relatively minor contribution of diatoms, while chrysophytes, dinoflagellates and chlorophytes were well represented; the heterotrophic eukaryote fraction was dominated by numerous ciliate taxa, and also included Heliozoa, Rhizaria, chytrids and flagellates. Autotrophic picoplankton occurred in cell concentrations up to 8.8 × 105 mL−1 (picocyanobacteria) and 4.6 × 105 mL−1 (picoeukaryotes). Both groups of picophytoplankton were positively correlated with total phytoplankton abundance, as measured by Chl a; picocyanobacteria were inversely correlated with dissolved organic carbon, while picoeukaryotes were correlated with conductivity. Despite their net heterotrophic character, subarctic thaw lakes are rich habitats for diverse phototrophic communities.
Climate model emulation in an integrated assessment framework: a case study for mitigation policies in the electricity sector
Authors: Foley A. M. , Holden P. B. , Edwards N. R. , Mercure J.-F. , Salas P. , Pollitt H. , Chewpreecha U.
Published: August 2015

Abstract. We present a carbon cycle-climate modelling framework using model emulation, designed for integrated assessment modelling, which introduces a new emulator of the carbon cycle (GENIEem). We demonstrate that GENIEem successfully reproduces the CO2 concentrations of the Representative Concentration Pathways when forced with the corresponding CO2 emissions and non-CO2 forcing. To demonstrate its application as part of the integrated assessment framework, we use GENIEem along with an emulator of the climate (PLASIM-ENTSem) to evaluate global CO2 concentration levels and spatial temperature and precipitation response patterns resulting from CO2 emission scenarios. These scenarios are modelled using a macroeconometric model (E3MG) coupled to a model of technology substitution dynamics (FTT:Power), and represent different emissions reduction policies applied solely in the electricity sector, without mitigation in the rest of the economy. The effect of cascading uncertainty is apparent, but despite uncertainties, it is clear that in all scenarios, global mean temperatures in excess of 2 °C above preindustrial levels are projected by the end of the century. Our approach also reveals the diverse temperature and precipitation patterns that could occur regionally in response to the global mean temperatures associated with these scenarios, enabling more robust impacts modelling and emphasising the necessity of focussing on spatial patterns in addition to global mean temperature change.
Assimilation of Antarctic velocity observations provides evidence for uncharted pinning points
Authors: Fürst J. J. , Durand G. , Gillet-Chaulet F. , Merino N. , Tavard L. , Mouginot J. , Gourmelen N. , Gagliardini O.
Published: August 2015

Abstract. In ice flow modelling, the use of control methods to assimilate the dynamic and geometric state of an ice body has become common practice. These methods have primarily focussed on inverting for one of the two least known properties in glaciology, namely the basal friction coefficient or the ice viscosity parameter. Here, we present an approach to infer both properties simultaneously for the whole of the Antarctic ice sheet. After the assimilation, the root-mean-square deviation between modelled and observed surface velocities attains 8.7 m a−1 for the entire domain, with a slightly higher value of 14.0 m a−1 for the ice shelves. An exception in terms of the velocity mismatch is the Thwaites Glacier Ice Shelf, where the RMS value is almost 70 m a−1. The reason is that the underlying Bedmap2 geometry ignores the presence of an ice rise, which exerts major control on the dynamics of the eastern part of the ice shelf. On these grounds, we suggest an approach to account for pinning points not included in Bedmap2 by locally allowing an optimisation of basal friction during the inversion. In this way, the velocity mismatch on the ice shelf of Thwaites Glacier is more than halved. A characteristic velocity mismatch pattern emerges for unaccounted pinning points close to the marine shelf front. This pattern is exploited to manually identify seven uncharted features around Antarctica that exert significant resistance to the shelf flow. Potential pinning points are detected on Fimbul, West, Shackleton, Nickerson and Venable ice shelves. As pinning points can provide substantial resistance to shelf flow, with considerable consequences if they became ungrounded in the future, the model community is in need of detailed bathymetry there. Our data assimilation points to some of these dynamically important features not present in Bedmap2 and implicitly quantifies their relevance.
Inequality and limits
Authors: Nardi Bonnie
Published: August 2015

Many indicators demonstrate growing economic inequality. Figure 1 depicts increasing economic disparity between social classes. Despite increased productivity, waged workers are losing ground because owners of capital are accumulating the wealth generated by increased productivity (Figure 2). Since wealth accumulation is the goal of capitalism, this is not surprising. Many forms of digitally mediated labor are not even waged any more, though they generate economic value. Digitally mediated labor includes casual labor managed in short-term contracts in systems such as Mechanical Turk, the uncompensated labor of self-service, and uncompensated “affective” labor. Because technology supports a global labor force, traditional mechanisms of ensuring fairness, such as labor unions, are not always operative. This paper considers the problem of the distribution of wealth, and suggests sociotechnical mechanisms for a world with fewer traditional jobs.
Cacophony: Building a resilient Internet of things
Authors: Brock John , Patterson Donald J.
Published: August 2015

The proliferation of sensors in the world has created increased opportunities for context-aware applications. However, it is often cumbersome to capitalize on these opportunities due to the difficulties inherent in collecting, fusing, and reasoning with data from a heterogeneous set of distributed sensors. The fabric that connects sensors lacks resilience and fault tolerance in the face of infrastructure intermittency. To address these difficulties, we introduce Cacophony, a network of peer-to-peer nodes (CNodes), where each node provides real-time predictions of a specified set of sensor data. The predictions from each of the Cacophony prediction nodes can be used by any application with access to the Web. Creating a new CNode involves three steps: (1) Developers and domain-knowledge experts, via a simple Web UI, specify which sensor data they care about. Possible sources of sensor data include stationary sensors, mobile sensors, and the real-time Web; (2) The CNode automatically aggregates data from the relevant sensors in real time using a JXTA-based peer-to-peer network; and, (3) The CNode uses the aggregated data to train a prediction model via the Weka machine-learning library (Hall, et al., 2009). Real-time predictions made by the CNode are then made publicly available to applications that wish to use data from a CNode’s particular set of sensors. The real-time predictions themselves can also be used recursively as sensor data, enabling the creation of CNodes that make predictions based on other CNodes.
On the limits of limits
Authors: Pargman Daniel
Published: August 2015

This discussion paper outlines the connection between the perceived urgency of environmental and resource challenges that humanity is facing during the twenty-first century and the individual researcher’s response within the emerging “Computing within Limits” community. What is the relationship between our beliefs as individuals and as researchers and the specific issues we chose to study? Furthermore, is there a relationship between skills and topics we happen to be expert in and the subsequent future scenarios we plan for and deem to be more likely to happen?
Cartilage Repair Using Composites of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells and Hyaluronic Acid Hydrogel in a Minipig Model
Authors: Ha Chul-Won , Park Yong-Beom , Chung Jun-Young , Park Yong-Geun
Published: August 2015

The cartilage regeneration potential of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) with a hyaluronic acid (HA) hydrogel composite has shown remarkable results in rat and rabbit models. The purpose of the present study was to confirm the consistent regenerative potential in a pig model using three different cell lines. A full-thickness chondral injury was intentionally created in the trochlear groove of each knee in 6 minipigs. Three weeks later, an osteochondral defect, 5 mm wide by 10 mm deep, was created, followed by an 8-mm-wide and 5-mm-deep reaming. A mixture (1.5 ml) of hUCB-MSCs (0.5 × 107 cells per milliliter) and 4% HA hydrogel composite was then transplanted into the defect on the right knee. Each cell line was used in two minipigs. The osteochondral defect created in the same manner on the left knee was untreated to act as the control. At 12 weeks postoperatively, the pigs were sacrificed, and the degree of subsequent cartilage regeneration was evaluated by gross and histological analysis. The transplanted knee resulted in superior and more complete hyaline cartilage regeneration compared with the control knee. The cellular characteristics (e.g., cellular proliferation and chondrogenic differentiation capacity) of the hUCB-MSCs influenced the degree of cartilage regeneration potential. This evidence of consistent cartilage regeneration using composites of hUCB-MSCs and HA hydrogel in a large animal model could be a stepping stone to a human clinical trial in the future.

Significance

To date, several studies have investigated the chondrogenic potential of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs); however, the preclinical studies are still limited in numbers with various results. In parallel, in the past several years, the cartilage regeneration potential of hUCB-MSCs with a hyaluronic acid (HA) hydrogel composite have been investigated and remarkable results in rat and rabbit models have been attained. (These experimental results are currently in preparation for publication.) Before applying the cartilage regeneration technique in a human clinical trial, it seemed necessary to confirm the consistent result in a larger animal model. At 12 weeks postoperatively, the minipigs were sacrificed, and the degree of subsequent cartilage regeneration was evaluated by gross and histological analysis. The transplanted knee resulted in superior and more complete hyaline cartilage regeneration compared with the control knee. This evidence of consistent cartilage regeneration with composites of hUCB-MSCs and HA hydrogel in a large animal model could be a stepping stone to a human clinical trial in the future.
A sintomatologia do stress sob a ótica da Medicina Tradicional Chinesa
Authors: Bastos Rodrigo Almeida
Published: August 2015

O desequilíbrio propiciado pelo stress desencadeia uma série de prejuízos aos diversos setores da vida dos indivíduos. A presença de stress pode desencadear o desenvolvimento de inúmeras doenças e propiciar um prejuízo para a qualidade de vida e produtividade do ser humano. A Medicina Tradicional Chinesa pode ser instrumento eficaz de avaliação e tratamento da presença do stress por visar à reorganização homeostática do organismo. Baseando-se na manutenção da qualidade de vida do ser humano, o presente estudo objetivou realizar uma revisão bibliográfica da sintomatologia do stress sob a ótica da Medicina Tradicional Chinesa. As relações encontradas entre a sintomatologia do stress e a Medicina Tradicional Chinesa foram: Vazio de Qi/Yang do Coração (Cansaço e Desgaste Físico), Estagnação do Qi do Fígado (Tensão Muscular), Fogo Fleuma do Coração, Estagnação do Qi do Coração e Fígado e Deficiência de Qi, Yin ou Sangue do Coração (Ansiedade/Angustia diária), Mucosidade-Fogo no Estômago e Coração (Pensamentos constantes em um só assunto), o Fogo no Coração que consome o Yin e Vazio de Sangue do Coração (Insônia). Estas inter-relações entre a Medicina Ocidental e a Medicina Tradicional Chinesa poderão ser importantes no direcionamento efetivo do tratamento da sintomatologia do stress.
Progressive Development of Creative Design Skills from Kindergarden Education
Authors: Yalcin Meryem
Published: August 2015

This article offers an alternative view of design education, emphasising on its introduction in kindergarten and proposing a curriculum that covers design issues for introduction in kinder­gar­ten. This approach is suited to developing creative thinking skills. In an environ­ment where children imagine, create, practice, modify, recognise, manipulate and share knowl­edge, experiences and objects are crucial in design education. Early childhood education should be advanced based on basic design issues—such as design principles, conceptuali­zation, 2D/3D spatial allocation and composition—more comprehensively, which will enable children to construct perceptual, critical and analytic view points at an early age and develop these perspectives in the future. Based on this argument, the study model for design education in kindergarten, which will instil in children strong design knowledge, as well as stimulate their cognitive development.
Imagining the unknown - Responsible creativity for a better tomorrow
Authors: Lutnæs Eva
Published: August 2015

This paper explores the scientific discourse on creativity in the field of design education, drawing upon 165 papers presented at the DRS//CUMULUS Oslo 2013 conference. The re­view shows creativity to be a key concept in the scientific discourse and identifies five story­lines that conceptualise creativity as a generic human capacity for which the field of design education eagerly claims responsibility. In the scientific discourse, the fostering of creativity is a leading motive when articulating reasons for design to gain terrain in general education. A multifaceted repertoire of strategies to solve design problems can drive new ideas or arte­facts that contribute to both environmental protection and degradation, human aid or human-made disasters. I discuss how to frame the relevant educational content of creativity as part of a general education that empowers citizens to promote sustainability and meet global chal­lenges ahead.
The Global Studio - Incorporating Peer-Learning into the Design Curriculum
Authors: Ghassan Aysar , Bohemia Erik
Published: August 2015

In ‘tutor-led’ design education, lecturers reside at the centre of teaching & learning activi­ties. We argue that tutor-led design education does not prepare graduates sufficiently for working in highly complex professional capacities. We outline an alternative learning envi­­ron­ment named the Global Studio in which lecturers are more ‘distant’ in pedagogical activities. This ‘distance’ opens up learning spaces which expose students to complex project situations in preparation for professional working life. Global Studio projects are ‘student-led’ and contain explicit opportunities for peer tutoring to ensue. Feedback indicates that learners benefitted from engaging in peer tutoring. However, many students struggled with making important decisions when operating outside of the tutor-led learning environment. To maximise their benefit, we argue that student-led projects featuring peer-tutoring should be scaffolded throughout design programmes to provide students with a sufficient level of expo­sure to this mode of learning. Image by artist Malcom Jones. http://www.malcomjones.com/index.htm
Testing keywords internationally to define and apply undergraduate assessment standards in art and design
Authors: Harland Robert
Published: August 2015

What language should be featured in assessment standards for international students? Have universities adjusted their assessment methods sufficiently to match the increased demand for studying abroad? How might art and design benefit from a more stable definition of standards? These are some questions this paper seeks to address by reporting the results of recent pedagogic research at the School of the Arts, Loughborough University, in the United Kingdom. Language use is at the heart of this issue, yet it is generally overlooked as an essential tool that links assessment, feedback and action planning for international students. The paper reveals existing and new data that builds on research since 2009, aimed at improving students’ assessment literacy. Recommendations are offered to stimulate local and global discussion about keyword use for defining undergraduate assessment standards in art and design.
Vernacular traditions in Norwegian jewelry design - Past, present, future
Authors: Skjerven Astrid
Published: August 2015

Living in an era of globalization, the capability of communicating identity has become of greater importance than ever. This has increased our estimation of the vernacular, which represents an expression of a national or local identity. In Norway the vernacular tradition in silver jewelry is particularly strong. It has played an important role not only locally, but also in the constantly changing relation with the outside world, in accordance with the societal situation. It should therefore constitute a reliable indicator of how our country relates to the present process of globalization. The aim of the paper is to throw light on the relation between Norway’s role on the global scene and the use of the vernacular tradition in the development of jewelry design in general. It consists of a historical exploration that leads up to a discussion the present and future situation. Today there is a cleft between consumer behavior and avant-garde practice. In accordance with the global situation and Norway’s geopolitical situation of existing in the outskirts of political and economic decisions, the situation is characterized by a variety of practices, and by a slow acceptance of the vernacular values in the world of avant-garde practitioners.
Working memory and background knowledge - Cognitive science in the design classroom
Authors: Trogu Pino
Published: August 2015

This article discusses two universal principles from cognitive psychology, and proposes some ways in which those principles relate to graphic design. The two most important principles are first, the strict constraints of working memory, a function which persists for only a few seconds, and second, the finding that perceptions and meanings are mediated by the cultural knowledge of viewers, including their knowledge of design conventions and genre. Better de-signs are likely to emerge from the designer’s familiarity with these psychological and cultur-al principles. Visual examples, including maps and student projects, illustrate how the two principles are useful for classroom instruction.
The multiple fates of sinking particles in the North Atlantic Ocean
Authors: Collins James R. , Edwards Bethanie R. , Thamatrakoln Kimberlee , Ossolinski Justin E. , DiTullio Giacomo R. , Bidle Kay D. , Doney Scott C. , Van Mooy Benjamin A. S.
Published: August 2015

The direct respiration of sinking organic matter by attached bacteria is often invoked as the dominant sink for settling particles in the mesopelagic ocean. However, other processes, such as enzymatic solubilization and mechanical disaggregation, also contribute to particle flux attenuation by transferring organic matter to the water column. Here we use observations from the North Atlantic Ocean, coupled to sensitivity analyses of a simple model, to assess the relative importance of particle‐attached microbial respiration compared to the other processes that can degrade sinking particles. The observed carbon fluxes, bacterial production rates, and respiration by water column and particle‐attached microbial communities each spanned more than an order of magnitude. Rates of substrate‐specific respiration on sinking particle material ranged from 0.007 ± 0.003 to 0.173 ± 0.105 day−1. A comparison of these substrate‐specific respiration rates with model results suggested sinking particle material was transferred to the water column by various biological and mechanical processes nearly 3.5 times as fast as it was directly respired. This finding, coupled with strong metabolic demand imposed by measurements of water column respiration (729.3 ± 266.0 mg C m−2 d−1, on average, over the 50 to 150 m depth interval), suggested a large fraction of the organic matter evolved from sinking particles ultimately met its fate through subsequent remineralization in the water column. At three sites, we also measured very low bacterial growth efficiencies and large discrepancies between depth‐integrated mesopelagic respiration and carbon inputs.
An intensified seasonal transition in the Central U.S. that enhances summer drought
Authors: Wang S.‐Y. Simon , Santanello Joseph , Wang Hailan , Barandiaran Daniel , Pinker Rachel T. , Schubert Siegfried , Gillies Robert R. , Oglesby Robert , Hilburn Kyle , Kilic Ayse , Houser Paul
Published: August 2015

In the long term, precipitation in the Central U.S. decreases by 25% during the seasonal transition from June to July. This precipitation decrease has intensified since 1979 and such intensification could have enhanced spring drought occurrences in the Central U.S., in which conditions quickly evolve from being abnormally dry to exceptionally dry. Various atmospheric and land reanalysis data sets were analyzed to examine the trend in the June–July seasonal transition. The intensified deficit in precipitation is accompanied by increased downward shortwave radiation flux, tropospheric subsidence, enhanced evaporative fraction, and elevated planetary boundary layer height, all of which can lead to surface drying. The change in tropospheric circulation was characterized by an anomalous ridge over the western U.S. and a trough on either side—a pattern known to suppress rainfall in the Central U.S. This trending pattern shows similarity with the progression of the 2012 record drought.
Chemical and Pb isotope composition of phenocrysts from bentonites constrains the chronostratigraphy around the Cretaceous‐Paleogene boundary in the Hell Creek region, Montana
Authors: Ickert Ryan B. , Mulcahy Sean R. , Sprain Courtney J. , Banaszak Jessica F. , Renne Paul R.
Published: August 2015

An excellent record of environmental and paleobiological change around the Cretaceous‐Paleogene boundary is preserved in the Hell Creek and Fort Union Formations in the western Williston Basin of northeastern Montana. These records are present in fluvial deposits whose lateral discontinuity hampers long‐distance correlation. Geochronology has been focused on bentonite beds that are often present in lignites. To better identify unique bentonites for correlation across the region, the chemical and Pb isotopic composition of feldspar and titanite has been measured on 46 samples. Many of these samples have been dated by 40Ar/39Ar. The combination of chemical and isotopic compositions of phenocrysts has enabled the identification of several unique bentonite beds. In particular, three horizons located at and above the Cretaceous‐Paleogene boundary can now be traced—based on their unique compositions—across the region, clarifying previously ambiguous stratigraphic relationships. Other bentonites show unusual features, such as Pb isotope variations consistent with magma mixing or assimilation, that will make them easy to recognize in future studies. This technique is limited in some cases by more than one bentonite having compositions that cannot be distinguished, or bentonites with abundant xenocrysts. The Pb isotopes are consistent with a derivation from the Bitterroot Batholith, whose age range overlaps that of the tephra. These data provide an improved stratigraphic framework for the Hell Creek region and provide a basis for more focused tephrostratigraphic work, and more generally demonstrate that the combination of mineral chemistry and Pb isotope compositions is an effective technique for tephra correlation.
Partial melting of a Pb‐Sn mushy layer due to heating from above, and implications for regional melting of Earth's directionally solidified inner core
Authors: Yu James , Bergman Michael I. , Huguet Ludovic , Alboussiere Thierry
Published: August 2015

Superimposed on the radial solidification of Earth's inner core may be hemispherical and/or regional patches of melting at the inner‐outer core boundary. Little work has been carried out on partial melting of a dendritic mushy layer due to heating from above. Here we study directional solidification, annealing, and partial melting from above of Pb‐rich Sn alloy ingots. We find that partial melting from above results in convection in the mushy layer, with dense, melted Pb sinking and resolidifying at a lower height, yielding a different density profile than for those ingots that are just directionally solidified, irrespective of annealing. Partial melting from above causes a greater density deeper down and a corresponding steeper density decrease nearer the top. There is also a change in microstructure. These observations may be in accordance with inferences of east‐west and perhaps smaller‐scale variations in seismic properties near the top of the inner core.
Detection of recent regional sea surface temperature warming in the Caribbean and surrounding region
Authors: Glenn Equisha , Comarazamy Daniel , González Jorge E. , Smith Thomas
Published: August 2015

We show a sea surface temperature (SST) warming trend for the Caribbean and surrounding region over 1982–2012. Using an optimum interpolated SST product, a 30 year climatological analysis was generated to observe annual, monthly, and seasonal trends. Results show that SSTs are increasing annually for the region. For the two Caribbean rainy seasons, the Early Rainfall Season (ERS) and the Late Rainfall Season (LRS), estimated trends at 0.0161°C yr−1 and 0.0209°C yr−1 were observed, with high statistical significance. Subregional analysis revealed that warming is greatest in the Gulf of Mexico and north of South America during the ERS and LRS. Additionally, LRS averages for 1998–2012 reflect an increase in magnitude and intensity of the Atlantic Warm Pool (AWP) since the 1983–1997 period reflected in the AWP Area Index. Extreme increases/decreases in the time series show potential correlation with El Niño and the Southern Oscillation.
Electrostatic solitary waves observed at Saturn by Cassini inside 10 Rs and near Enceladus
Authors: Pickett J. S. , Kurth W. S. , Gurnett D. A. , Huff R. L. , Faden J. B. , Averkamp T. F. , Píša D. , Jones G. H.
Published: August 2015

We have analyzed the Cassini Radio and Plasma Wave Science Wideband Receiver (WBR) data specifically looking for the presence of bipolar electrostatic solitary waves (ESWs). Typical examples of these ESWs are provided to show that when they are present, several of them may be detected over a few to several millisecond time span. We carried out an event study of an Enceladus encounter which took place on 9 October 2008. Approximately 30 min prior to and during the crossing of the Enceladus dust plume, several ESWs are observed with amplitudes of about 100 μV/m up to about 140 mV/m, and time durations of several tens of microseconds up to 250 µs. The highest amplitudes (over 10 mV/m) were observed only during the closest approach to Enceladus. We also carried out an ESW survey using the WBR for all years from 2004 to 2008 for distances less than 10 Rs. The survey clearly shows that most of the ESWs are found on the nightside, with a high percentage of them in the range of 4–6 Rs. This location is consistent with the densest part of Saturn's E ring and Enceladus' orbit. These are the first extended survey results of ESWs near Saturn and the first reported ESWs in connection with Enceladus. We discuss possibilities for the generation of these nonlinear ESWs, which involve current, beam, and acoustic, including dust, instabilities.
Thermodynamics of the MgO‐FeO‐SiO2system up to 140 GPa: Application to the crystallization of Earth's magma ocean
Authors: Boukaré C.‐E. , Ricard Y. , Fiquet G.
Published: August 2015

At the end of Earth's accretion and after the core‐mantle segregation, the existence of a basal magma ocean at the top of the core‐mantle boundary (CMB) depends on the physical properties of mantle materials at relevant pressure and temperature. Present‐day deep mantle structures such as ultralow‐velocity zones and low‐shear velocity provinces might be directly linked to the still ongoing crystallization of a primordial magma ocean. We provide the first steps toward a self‐consistent thermodynamic model of magma ocean crystallization at high pressure. We build a solid‐liquid thermodynamic database for silicates in the MgO‐FeO‐SiO2system from 20 GPa to 140 GPa. We use already published chemical potentials for solids, liquid MgO, and SiO2. We derive standard state chemical potential for liquid FeO and mixing relations from various indirect observations. Using this database, we compute the ternary phase diagram in the MgO‐FeO‐SiO2system as a function of temperature and pressure. We confirm that the melt is lighter than the solid of same composition for all mantle conditions but at thermodynamic equilibrium, the iron‐rich liquid is denser than the solid in the deep mantle. We compute a whole fractional crystallization sequence of the mantle and show that an iron‐rich and fusible layer should be left above the CMB at the end of the crystallization.
Wave gradiometry and its link with Helmholtz equation solutions applied to USArray in the eastern U.S.
Authors: Liu Yuanyuan , Holt William E.
Published: August 2015

Wave gradiometry is an array processing technique utilizing the shape of seismic wavefields captured by USArray TA stations to determine fundamental wave propagation characteristics. We first explore a compatibility relation that links the displacement spatial gradients to seismogram displacements and velocities through two unknown coefficients,
and
. These coefficients are solved for through iterative, damped least squares inversion to provide estimates of phase velocity, back azimuth, radiation pattern, and geometrical spreading. We show that the
coefficient corresponds to the gradient of logarithmic amplitude, and the
coefficient corresponds approximately to the local wave slowness.
and
vector fields are interpolated to explore a second compatibility relation through solutions to the Helmholtz equation. For most wavefields passing through the eastern U.S., we show that the
coefficients are generally orthogonal to the
coefficients. Where they are not completely orthogonal, there is a strong positive correlation between
and changes in geometrical spreading, which can be further linked with areas of strong energy focusing and defocusing. We finally obtain isotropic Rayleigh wave phase velocity maps for 15 periods between 20 and 150 s, by stacking results from 37 earthquakes, which show a velocity change along the approximate boundary of the early Paleozoic continental margin. We also observe two low‐velocity anomalies, one centered over the central Appalachians where Eocene basaltic volcanism has occurred and the other within the northeastern U.S., possibly associated with the Great Meteor Hotspot track.
Optical and hygroscopic properties of long‐range transported haze plumes observed at Deokjeok Island off the west coast of the Korean Peninsula under the Asian continental outflows
Authors: Jung Jinsang , Lee KwangYul , Cayetano Mylene G. , Batmunkh Tsatsral , Kim Young J.
Published: August 2015

An intensive field campaign was conducted on Deokjeok Island off the west coast of the Korean Peninsula during spring 2009 to characterize the optical and hygroscopic properties of Asian continental outflows. A slightly high wavelength dependence of light absorption coefficient, α of 1.6 ± 0.05 (average ± 1· standard deviation), and a low humidity‐dependent light scattering enhancement factor at 80% relative humidity, f(80%) (2.0 ± 0.2), were obtained when air masses originated from the northern part of China (N China), compared to those obtained when air masses originated from the eastern part of China (E China) (α = 1.4 ± 0.1; f(80%) = 2.4 ± 0.2). The relatively high α and low f(80%) during the N China compared to those during the E China were consistent with a relatively high mass ratio of organic aerosol to sum of SO42−, NO3−, and NH4+ during the N China (1.01 ± 0.17) compared to the E China episode (0.25 ± 0.13). This result indicates the importance of organic aerosol on aerosol optical and hygroscopic properties of haze plumes. Single scattering albedo (SSA) of dry particulate matter with a diameter less than or equal to 2.5 µm (PM2.5) (0.92 ± 0.01) and mass scattering efficiency (MSE) of dry PM2.5 at 550 nm wavelength during the E China episode (3.6 ± 0.3 m2 g−1) were higher than those previously obtained at the air mass source regions in China (SSA = ~0.8; MSE = ~3.0 m2 g−1), implying that optical properties of PM2.5 were significantly altered during long‐range atmospheric transport.
Frozen soil degradation and its effects on surface hydrology in the northern Tibetan Plateau
Authors: Cuo Lan , Zhang Yongxin , Bohn Theodore J. , Zhao Lin , Li Jialuo , Liu Qiming , Zhou Bingrong
Published: August 2015

Frozen soil was simulated at six seasonally frozen and seven permafrost stations over the northern Tibetan Plateau using the Variable Infiltration Capacity (VIC) model for the period of 1962–2009. The VIC model resolved the seasonal cycle and temporal evolution of the observed soil temperatures and liquid soil moisture well. The simulated long‐term changes during 1962–2009 indicated mostly positive trends for both soil temperature and soil moisture, and negative trends for soil ice content at annual and monthly time scales, although differences existed among the stations, soil layers, and seasons. Increases in soil temperature were due mainly to increases in daily air temperature maxima and internal soil heat conduction, while decreases in soil ice content were related to the warming of frozen soil. For liquid soil moisture, increases in the cold months can be attributed to increases in soil temperature and enhanced soil ice melt while changes in the warm months were the results of competition between positive precipitation and negative soil temperature effects. Precipitation and liquid soil moisture were strongly correlated with evapotranspiration and runoff but had various degrees of correlations with base flow during May–September. Seasonally frozen stations displayed longer and more active hydrological processes than permafrost stations. Slight enhancement of the surface hydrological processes at the study stations was indicated, due to the combined effects of precipitation changes, which were dominant, and frozen soil degradation.
Aurorasaurus: A citizen science platform for viewing and reporting the aurora
Authors: MacDonald E. A. , Case N. A. , Clayton J. H. , Hall M. K. , Heavner M. , Lalone N. , Patel K. G. , Tapia A.
Published: August 2015

A new, citizen science‐based, aurora observing and reporting platform has been developed with the primary aim of collecting auroral observations made by the general public to further improve the modeling of the aurora. In addition, the real‐time ability of this platform facilitates the combination of citizen science observations with auroral oval models to improve auroral visibility nowcasting. Aurorasaurus provides easily understandable aurora information, basic gamification, and real‐time location‐based notification of verified aurora activity to engage citizen scientists. The Aurorasaurus project is one of only a handful of space weather citizen science projects and can provide useful results for the space weather and citizen science communities. Early results are promising with over 2000 registered users submitting over 1000 aurora observations and verifying over 1700 aurora sightings posted on Twitter.
The Shillong Plateau and the great 1897 Assam earthquake
Authors: England Philip , Bilham Roger
Published: August 2015

Previous analysis of triangulation data of the Survey of India concluded that the great 1897 Assam earthquake occurred on a south dipping fault near the northern edge of the Shillong Plateau, which was named the Oldham fault. This attribution has been questioned on geological and geodetic grounds. We refine the triangulation data, adding recently discovered observations, and demonstrate that they require average slip of 25 ± 5 m on a fault that dips south at ∼40° beneath the plateau. The best fitting solution to the geodetic observations gives a rupture length of 79 km. However, the Chedrang fault, immediately to the west of the Oldham fault, appears to have slipped as a subvertical tear fault during or shortly after the 1897 earthquake, with over 10 m of down‐to‐the‐west normal‐sense slip. This observation suggests that the western end of the main rupture approached within a few kilometers of the Chedrang fault, giving a length of 95 km for the rupture. This range of parameters gives a magnitude 8.15<Mw<8.35 for the earthquake. The triangulation data cannot be satisfied by slip on the north dipping faults that border the southern edge of the Shillong Plateau nor by slip on a south dipping fault that has been postulated in the Brahmaputra Valley. GPS velocities show that up to 5 mm/yr of shortening is taken up across the plateau and its borders; this suggests, via moment‐frequency relations, that the interval between great earthquakes in the region is several thousand years but that earthquakes of magnitude 7 or greater should occur roughly once per century.
Text–Picture Integration: How Delayed Testing Moderates Recognition of Pictorial Information in Multimedia Learning
Authors: Arndt Jana , Schüler Anne , Scheiter Katharina
Published: August 2015

When learning with multimedia, text and pictures are assumed to be integrated with each other. Arndt, Schüler, and Scheiter (Learning & Instruction, 35, 62–72, 2015) confirmed the process of text picture integration for sentence recognition, not, however, for picture recognition. The current paper investigates the underlying reasons for the latter finding. Two experiments are reported, where subjects memorized text–picture stimuli that differed in the specificity of information contained in either sentences or pictures. In a subsequent picture recognition test, subjects showed no integration effect after a 30‐minute delay (Experiments 1 and 2), but only after a 1‐week delay (Experiment 2). Furthermore, eye‐tracking data showed that participants sufficiently processed the pictures during learning (Experiment 1). This data pattern speaks in favor of the assumption that after a short delay participants had available a short‐lived pictorial surface representation, which masked the integration effect for pictorial recognition.Copyright © 2015 John Wiley & Sons, Ltd.
Stretchable Chemical Patterns for the Assembly and Manipulation of Arrays of Microdroplets with Lensing and Micromixing Functionality
Authors: Bowen John J. , Taylor Jay M. , Jurich Christopher P. , Morin Stephen A.
Published: August 2015

The chemical properties of a surface are readily controlled using a layer (or layers) of surface‐functional groups that can be generated with, for example, self‐assembled monolayers (SAMs) or polymer brushes. These methods have enabled rational control over surface chemistry, which directly impacts surface properties, such as wettability, but generally follow a serial approach to building up surface‐functional groups (i.e., separate chemical steps are needed for the initial and each subsequent surface modification). This paper describes systems based on soft materials—stretchable chemical patterns—that have surface properties that are easily and reversibly modified using mechanical deformations. These systems couple surface‐chemical features such as the density and arrangement of functional groups on elastomeric polymers (e.g., polydimethylsiloxane) to mechanically induced surface deformations. This approach enables rapid and reversible control of surface chemistry and thus surface properties and processes. The behavior of these systems is characterized using fluorescent molecules and their utility illustrated through the organization and manipulation of arrays of micrometer‐scale droplets, which have optical and small‐volume mixing functionalities applicable to microlens and microreactor technologies, respectively. The capabilities of these systems may be extended to, for example, the control of heterogeneous nucleation, surface reactivity, and micro/nanoscale assembly.
Fully Printed Foldable Integrated Logic Gates with Tunable Performance Using Semiconducting Carbon Nanotubes
Authors: Cai Le , Zhang Suoming , Miao Jinshui , Yu Zhibin , Wang Chuan
Published: August 2015

The realization of large‐area and low‐cost flexible macroelectronics relies on both the advancements in materials science and the innovations in manufacturing techniques. In this study, extremely bendable and foldable carbon nanotube thin film transistors and integrated logic gates are fabricated on a piece of ultrathin polyimide substrate through an ink‐jet‐like printing process. The adoption of a hybrid gate dielectric layer consisting of barium titanate nanoparticles and poly(methyl methacrylate) has led to not only excellent gating effect but also superior mechanical compliance. The device characteristics show negligible amount of change after up to 1000 cycles of bending tests with curvature radii down to 1 mm, as well as very aggressive folding tests. Additionally, the electrical characteristics of each integrated logic gate can be tuned and optimized individually by using different numbers of carbon nanotube printing passes for different devices, manifesting the unique adaptability of ink‐jet printing as a digital, additive, and maskless method. This report on fully printed and foldable integrated logic gates represents an inspiring advancement toward the practical applications of carbon nanotubes for high‐performance and low‐cost ubiquitous flexible electronics.