bluuebunny/crossref_metadata_2025 huggingface dataset:
Mini-Workshop: Dynamics of Trace Maps and Applications to Spectral Theory
Authors: Damanik David , Gorodetski Anton
Published: September 2011

Recently some exciting results for the spectrum of Schrödinger operators with self-similar potentials and the dynamics of the associated Schrödinger equation have been established using input from complex and smooth dynamics. The workshop allowed us to bring together experts in dynamical systems, spectral theory, and quasi-crystals to study these deep and promising relations.
Mini-Workshop: Mathematical Analysis for Peridynamics
Authors: Emmrich Etienne , Gunzburger Max , Lehoucq Richard B.
Published: September 2011

A mathematical analysis for peridynamics, a nonlocal elastic theory, is the subject of the mini-workshop. Peridynamics is a novel multiscale mechanical model where the canonical divergence of the stress tensor is replaced by an integral operator that sums forces at a finite distance. As such, the underlying regularity assumptions are more general, for instance, allowing discontinuous and non-differentiable displacement fields. Although the theoretical mechanical formulation of peridynamics is well understood, the mathematical and numerical analyses are in their early stages. The mini-workshop proved to be a catalyst for the emerging mathematical analyses among an international group of mathematicians.
Stochastic Analysis in Finance and Insurance
Authors: Kramkov Dmitry , Schweizer Martin , Touzi Nizar
Published: September 2011

This workshop brought together leading experts and a large number of younger researchers in stochastic analysis and mathematical finance from all over the world. During a highly intense week, participants exchanged during talks and discussions many ideas and laid foundations for new collaborations and further developments in the field.
Trends in Mathematical Imaging and Surface Processing
Authors: Caselles Vicent , Rumpf Martin , Sapiro Guillermo , Schröder Peter
Published: September 2011

Motivated both by industrial applications and the challenge of new problems, one observes an increasing interest in the field of image and surface processing over the last years. It has become clear that even though the applications areas differ significantly the methodological overlap is enormous. Even if contributions to the field come from almost any discipline in mathematics, a major role is played by partial differential equations and in particular by geometric and variational modeling and by their numerical counterparts. The aim of the workshop was to gather a group of leading experts coming from mathematics, engineering and computer graphics to cover the main developments.
TESOL and TESD in Remote Aboriginal Australia: The “True” Story?
Authors: CADMAN KATE , BROWN JILL
Published: September 2011

It is widely recognised that teaching English to speakers of other languages (TESOL) and teaching English as a second dialect (TESD) in remote Indigenous Australia have a history of repeated failure of both policy and practice. National language testing has been been forcefully attacked by TESOL specialists, producing strong debate amongst politicians and educators. Meanwhile, the teachers in these remote communities, usually female, non‐Indigenous outsiders, are not consulted and rarely remain in these teaching locations. This article tells the story of how we, as researchers, developed a narrative inquiry project to investigate the situated stories of three teachers. Most immediately we noted how the stories we heard were as shocking for their silences as for what they told us, and the “truth” they offered lay primarily in the magnetism of narrative itself through the vitality of the “self” that came to life within the teacher's story. Unpredictably, however, and of greater significance for our understanding, our project confronted us with our own complicity in the silencing technologies effected by both the methodological processes and textual products of narrative study. We came to conclude that there is an inherent paradox at the heart of narrative inquiry which must be addressed in all its complexity if its emancipatory and voice‐releasing goals are to be realised.
Harnessing Storytelling as a Sociopragmatic Skill: Applying Narrative Research to Workplace English Courses
Authors: HOLMES JANET , MARRA MEREDITH
Published: September 2011

Narratives are often overlooked in workplace talk, but they contribute in crucial ways to relationship building and identity construction in workplace interaction. In this article we analyse narratives told by skilled migrants from non‐English‐speaking backgrounds during a workplace internship conducted as part of a Workplace Communication course. The analysis adopts a social constructionist stance recognising that narratives are co‐constructed between interactants in ongoing interaction. Although earlier TESOL research has made use of narratives as a source of information for designing teaching programmes and for improving specific linguistic features of fluency, this article demonstrates that narratives also provide (ESOL) teachers with an opportunity to empower students in their efforts to negotiate high‐stakes environments such as workplace settings.
Narratives of Classroom Life: Changing Conceptions of Knowledge
Authors: NELSON CYNTHIA D.
Published: September 2011

Narratives of classroom life—the type that blend analysis with artistry, in the form of plays, poems, stories, and the like—remain relatively uncommon within language education research. Yet such narratives have the potential to make a significant and timely contribution to the field, given the ways in which knowledge is being reconceptualised in this postmodern, transglobal era. Here I make a case that incorporating crafted classroom‐life narratives into language education's research repertoire—within a body of work that I propose be calledcritical narrative studies—can help to address the field's changing needs by further democratising knowledge production and exchange, illuminating subtle yet vital dimensions of classroom interactions, and prompting imaginative interpretations and revisionings. My argument draws together relevant strands of applied linguistics research; narrative theories and research from education, sociology, and the arts; and several classroom narratives of mine. I conclude with recommendations for enhancing the rigour and reach of studies that incorporate narratives of classroom life, in light of some important dilemmas and cautions.
REVIEWS
Authors: HACKER PENNY
Published: September 2011

Narratives of Learning and Teaching EFL Paula Kalaja, Vera Menezes, and Ana Maria F. Barcelos

Language and Culture: Reflective Narratives and the Emergence of Identity David Nunan and Julie Choi
Researcher Identity, Narrative Inquiry, and Language Teaching Research
Authors: NORTON BONNY , EARLY MARGARET
Published: September 2011

Whereas there has been much research on language and identity with respect to learners, teachers, and teacher educators, there has been little focus on the identity of the researcher, an important stakeholder in language education. Our research therefore addresses the following question: To what extent can narrative inquiry illuminate the ways in which researcher identity is negotiated in language teaching research? To address this question, we draw on a digital literacy study in multilingual Uganda to narrate how we engaged in our own storytelling, and the process by which we invited teachers to share their experiences of teaching through the medium of English as an additional language in a poorly resourced rural school. Central themes were our attempts to reduce power differentials between researchers and teachers, and our desire to increase teacher investment (Norton, 2000) in our collaborative research project. Drawing on numerous small stories (Bamberg, 2004; Georgakopoulou, 2006), we argue that several researcher identities were realized, including international guest, collaborative team member, teacher, and teacher educator. Our article supports the case that small stories enrich traditional narrative inquiry, both theoretically and methodologically, and make visible the complex ways in which researcher identity impacts research, not only in language teaching, but in education more broadly.
Quantification of the volatility of secondary organic compounds in ultrafine particles during nucleation events
Authors: Pierce J. R. , Riipinen I. , Kulmala M. , Ehn M. , Petäjä T. , Junninen H. , Worsnop D. R. , Donahue N. M.
Published: September 2011

Abstract. Condensation of secondary organic compounds onto ultrafine aerosols is important for growing these particles to sizes where they can act as cloud condensation nuclei. The organic flux to ultrafine particles depends strongly on the volatility of the condensing compounds. This paper presents quantitative estimates of the volatility of secondary organic aerosol (SOA) in freshly nucleated particles. We examine 13 nucleation/growth events in two remote continental locations, Hyytiälä, Finland and Egbert, ON, Canada. Two independent methods are used to quantify the volatility of the growing nucleation mode: (1) modelling of the growing nucleation mode to determine which volatilities allow the model to reproduce observed growth, and (2) modelling of the evaporation of heated aerosols in a Volatility Differential Mobility Particle Sizer to determine which volatilities allow the model to reproduce the observed evaporation. We find that the average saturation vapor concentration (C*) in the freshly nucleated particles (once Dp > 3 nm) is likely less than 10−3–10−2 μg m−3 (this corresponds to 3 × 106−3 × 107 molecules cm−3 and a saturation vapor pressure of 10−8–10−7 Pa). This maximum volatility depends somewhat on other uncertain factors that affect the size-dependent condensation of secondary organic compounds such as the surface tension, mass accommodation coefficient and the volatility of the pre-existing aerosols. However, our tests suggest that under no reasonable assumptions can the SOA in the ultrafine particles contain a majority of compounds with C* > 10−2 μg m−3. We demonstrate that the growth could be driven by either gas-phase or particle-phase chemistry but cannot conclude which is responsible for the low-volatility SOA.
On the relationship between low cloud variability and lower tropospheric stability in the Southeast Pacific
Authors: Sun F. , Hall A. , Qu X.
Published: September 2011

Abstract. In this study, we examine marine low cloud cover variability in the Southeast Pacific and its association with lower-tropospheric stability (LTS) across a spectrum of timescales. On both daily and interannual timescales, LTS and low cloud amount are very well correlated in austral summer (DJF). Meanwhile in winter (JJA), when ambient LTS increases, the LTS–low cloud relationship substantially weakens. The DJF LTS–low cloud relationship also weakens in years with unusually large ambient LTS values. These are generally strong El Niño years, in which DJF LTS values are comparable to those typically found in JJA. Thus the LTS–low cloud relationship is strongly modulated by the seasonal cycle and the ENSO phenomenon. We also investigate the origin of LTS anomalies closely associated with low cloud variability during austral summer. We find that the ocean and atmosphere are independently involved in generating anomalies in LTS and hence variability in the Southeast Pacific low cloud deck. This highlights the importance of the physical (as opposed to chemical) component of the climate system in generating internal variability in low cloud cover. It also illustrates the coupled nature of the climate system in this region, and raises the possibility of cloud feedbacks related to LTS. We conclude by addressing the implications of the LTS–low cloud relationship in the Southeast Pacific for low cloud feedbacks in anthropogenic climate change.
Global cloud condensation nuclei influenced by carbonaceous combustion aerosol
Authors: Spracklen D. V. , Carslaw K. S. , Pöschl U. , Rap A. , Forster P. M.
Published: September 2011

Abstract. Black carbon in carbonaceous combustion aerosol warms the climate by absorbing solar radiation, meaning reductions in black carbon emissions are often perceived as an attractive global warming mitigation option. However, carbonaceous combustion aerosol can also act as cloud condensation nuclei (CCN) so they also cool the climate by increasing cloud albedo. The net radiative effect of carbonaceous combustion aerosol is uncertain because their contribution to CCN has not been evaluated on the global scale. By combining extensive observations of CCN concentrations with the GLOMAP global aerosol model, we find that the model is biased low (normalised mean bias = −77 %) unless carbonaceous combustion aerosol act as CCN. We show that carbonaceous combustion aerosol accounts for more than half (52–64 %) of global CCN with the range due to uncertainty in the emitted size distribution of carbonaceous combustion particles. The model predicts that wildfire and pollution (fossil fuel and biofuel) carbonaceous combustion aerosol causes a global mean cloud albedo aerosol indirect effect of −0.34 W m−2, with stronger cooling if we assume smaller particle emission size. We calculate that carbonaceous combustion aerosol from pollution sources cause a global mean aerosol indirect effect of −0.23 W m−2. The small size of carbonaceous combustion particles from fossil fuel sources means that whilst pollution sources account for only one-third of the emitted mass they cause two-thirds of the cloud albedo aerosol indirect effect that is due to carbonaceous combustion aerosol. This cooling effect must be accounted for, along with other cloud effects not studied here, to ensure that black carbon emissions controls that reduce the high number concentrations of fossil fuel particles have the desired net effect on climate.
Composition changes after the "Halloween" solar proton event: the High Energy Particle Precipitation in the Atmosphere (HEPPA) model versus MIPAS data intercomparison study
Authors: Funke B. , Baumgaertner A. , Calisto M. , Egorova T. , Jackman C. H. , Kieser J. , Krivolutsky A. , López-Puertas M. , Marsh D. R. , Reddmann T. , Rozanov E. , Salmi S.-M. , Sinnhuber M. , Stiller G. P. , Verronen P. T. , Versick S. , von Clarmann T. , Vyushkova T. Y. , Wieters N. , Wissing J. M.
Published: September 2011

Abstract. We have compared composition changes of NO, NO2, H2O2, O3, N2O, HNO3, N2O5, HNO4, ClO, HOCl, and ClONO2 as observed by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on Envisat in the aftermath of the "Halloween" solar proton event (SPE) in late October 2003 at 25–0.01 hPa in the Northern Hemisphere (40–90° N) and simulations performed by the following atmospheric models: the Bremen 2-D model (B2dM) and Bremen 3-D Chemical Transport Model (B3dCTM), the Central Aerological Observatory (CAO) model, FinROSE, the Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA), the Karlsruhe Simulation Model of the Middle Atmosphere (KASIMA), the ECHAM5/MESSy Atmospheric Chemistry (EMAC) model, the modeling tool for SOlar Climate Ozone Links studies (SOCOL and SOCOLi), and the Whole Atmosphere Community Climate Model (WACCM4). The large number of participating models allowed for an evaluation of the overall ability of atmospheric models to reproduce observed atmospheric perturbations generated by SPEs, particularly with respect to NOy and ozone changes. We have further assessed the meteorological conditions and their implications for the chemical response to the SPE in both the models and observations by comparing temperature and tracer (CH4 and CO) fields. Simulated SPE-induced ozone losses agree on average within 5 % with the observations. Simulated NOy enhancements around 1 hPa, however, are typically 30 % higher than indicated by the observations which are likely to be related to deficiencies in the used ionization rates, though other error sources related to the models' atmospheric background state and/or transport schemes cannot be excluded. The analysis of the observed and modeled NOy partitioning in the aftermath of the SPE has demonstrated the need to implement additional ion chemistry (HNO3 formation via ion-ion recombination and water cluster ions) into the chemical schemes. An overestimation of observed H2O2 enhancements by all models hints at an underestimation of the OH/HO2 ratio in the upper polar stratosphere during the SPE. The analysis of chlorine species perturbations has shown that the encountered differences between models and observations, particularly the underestimation of observed ClONO2 enhancements, are related to a smaller availability of ClO in the polar night region already before the SPE. In general, the intercomparison has demonstrated that differences in the meteorology and/or initial state of the atmosphere in the simulations cause a relevant variability of the model results, even on a short timescale of only a few days.
Nucleation and growth of sulfate aerosol in coal-fired power plant plumes: sensitivity to background aerosol and meteorology
Authors: Stevens R. G. , Pierce J. R. , Brock C. A. , Reed M. K. , Crawford J. H. , Holloway J. S. , Ryerson T. B. , Huey L. G. , Nowak J. B.
Published: September 2011

Abstract. New-particle formation in the plumes of coal-fired power plants and other anthropogenic sulfur sources may be an important source of particles in the atmosphere. It remains unclear, however, how best to reproduce this formation in global and regional aerosol models with grid-box lengths that are 10 s of kilometers and larger. The predictive power of these models is thus limited by the resultant uncertainties in aerosol size distributions. In this paper, we focus on sub-grid sulfate aerosol processes within coal-fired power plant plumes: the sub-grid oxidation of SO2 with condensation of H2SO4 onto newly-formed and pre-existing particles. We have developed a modeling framework with aerosol microphysics in the System for Atmospheric Modelling (SAM), a Large-Eddy Simulation/Cloud-Resolving Model (LES/CRM). The model is evaluated against aircraft observations of new-particle formation in two different power-plant plumes and reproduces the major features of the observations. We show how the downwind plume aerosols can be greatly modified by both meteorological and background aerosol conditions. In general, new-particle formation and growth is greatly reduced during polluted conditions due to the large pre-existing aerosol surface area for H2SO4 condensation and particle coagulation. The new-particle formation and growth rates are also a strong function of the amount of sunlight and NOx since both control OH concentrations. The results of this study highlight the importance for improved sub-grid particle formation schemes in regional and global aerosol models.
Aerosol hygroscopic growth parameterization based on a solute specific coefficient
Authors: Metzger S. , Steil B. , Xu L. , Penner J. E. , Lelieveld J.
Published: September 2011

Abstract. Water is a main component of atmospheric aerosols and its amount depends on the particle chemical composition. We introduce a new parameterization for the aerosol hygroscopic growth factor (HGF), based on an empirical relation between water activity (aw) and solute molality (μs) through a single solute specific coefficient νi. Three main advantages are: (1) wide applicability, (2) simplicity and (3) analytical nature. (1) Our approach considers the Kelvin effect and covers ideal solutions at large relative humidity (RH), including CCN activation, as well as concentrated solutions with high ionic strength at low RH such as the relative humidity of deliquescence (RHD). (2) A single νi coefficient suffices to parameterize the HGF for a wide range of particle sizes, from nanometer nucleation mode to micrometer coarse mode particles. (3) In contrast to previous methods, our analytical aw parameterization depends not only on a linear correction factor for the solute molality, instead νi also appears in the exponent in form x · ax. According to our findings, νi can be assumed constant for the entire aw range (0–1). Thus, the νi based method is computationally efficient. In this work we focus on single solute solutions, where νi is pre-determined with the bisection method from our analytical equations using RHD measurements and the saturation molality μssat. The computed aerosol HGF and supersaturation (Köhler-theory) compare well with the results of the thermodynamic reference model E-AIM for the key compounds NaCl and (NH4)2SO4 relevant for CCN modeling and calibration studies. The equations introduced here provide the basis of our revised gas-liquid-solid partitioning model, i.e. version 4 of the EQuilibrium Simplified Aerosol Model (EQSAM4), described in a companion paper.
Impacts of near-future cultivation of biofuel feedstocks on atmospheric composition and local air quality
Authors: Ashworth K. , Folberth G. , Hewitt C. N. , Wild O.
Published: September 2011

Abstract. Large-scale production of feedstock crops for biofuels will lead to land-use changes. We quantify the effects of realistic land use change scenarios for biofuel feedstock production on isoprene emissions and hence atmospheric composition and chemistry using the HadGEM2 model. Two feedstocks are considered: oil palm for biodiesel in the tropics and short rotation coppice (SRC) in the mid-latitudes. In total, 69 Mha of oil palm and 92 Mha of SRC are planted, each sufficient to replace just over 1 % of projected global fossil fuel demand in 2020. Both planting scenarios result in increases in total global annual isoprene emissions of about 1 %. In each case, changes in surface concentrations of ozone and biogenic secondary organic aerosol (bSOA) are significant at the regional scale and are detectable even at a global scale with implications for air quality standards. However, the changes in tropospheric burden of ozone and the OH radical, and hence effects on global climate, are negligible. The oil palm plantations and processing plants result in global average annual mean increases in ozone and bSOA of 38 pptv and 2 ng m−3 respectively. Over SE Asia, one region of planting, increases reach over 2 ppbv and 300 ng m−3 for large parts of Borneo. Planting of SRC causes global annual mean changes of 46 pptv and 3 ng m−3. Europe experiences peak monthly mean changes of almost 0.6 ppbv and 90 ng m−3 in June and July. Large areas of Central and Eastern Europe see changes of over 1.5 ppbv and 200 ng m−3 in the summer. That such significant atmospheric impacts from low level planting scenarios are discernible globally clearly demonstrates the need to include changes in emissions of reactive trace gases such as isoprene in life cycle assessments performed on potential biofuel feedstocks.
A two-dimensional volatility basis set – Part 2: Diagnostics of organic-aerosol evolution
Authors: Donahue N. M. , Kroll J. H. , Pandis S. N. , Robinson A. L.
Published: September 2011

Abstract. We discuss the use of a two-dimensional volatility-oxidation space (2-D-VBS) to describe organic-aerosol chemical evolution. The space is built around two coordinates, volatility and the degree of oxidation, both of which can be constrained observationally or specified for known molecules. Earlier work presented the thermodynamics of organics forming the foundation of this 2-D-VBS, allowing us to define the average composition (C, H, and O) of organics, including organic aerosol (OA) based on volatility and oxidation state. Here we discuss how we can analyze experimental data, using the 2-D-VBS to gain fundamental insight into organic-aerosol chemistry. We first present a well-understood "traditional" secondary organic aerosol (SOA) system – SOA from α-pinene + ozone, and then turn to two examples of "non-traditional" SOA formation – SOA from wood smoke and dilute diesel-engine emissions. Finally, we discuss the broader implications of this analysis.
Characterization of a volcanic ash episode in southern Finland caused by the Grimsvötn eruption in Iceland in May 2011
Authors: Kerminen V.-M. , Niemi J. V. , Timonen H. , Aurela M. , Frey A. , Carbone S. , Saarikoski S. , Teinilä K. , Hakkarainen J. , Tamminen J. , Vira J. , Prank M. , Sofiev M. , Hillamo R.
Published: September 2011

Abstract. The volcanic eruption of Grimsvötn in Iceland in May 2011, affected surface-layer air quality at several locations in Northern Europe. In Helsinki, Finland, the main pollution episode lasted for more than 8 h around the noon of 25 May. We characterized this episode by relying on detailed physical, chemical and optical aerosol measurements. The analysis was aided by air mass trajectory calculations, satellite measurements, and dispersion model simulations. During the episode, volcanic ash particles were present at sizes from less than 0.5 μm up to sizes >10 μm. The mass mean diameter of ash particles was a few μm in the Helsinki area, and the ash enhanced PM10 mass concentrations up to several tens of μg m−3. Individual particle analysis showed that some ash particles appeared almost non-reacted during the atmospheric transportation, while most of them were mixed with sea salt or other type of particulate matter. Also sulfate of volcanic origin appeared to have been transported to our measurement site, but its contribution to the aerosol mass was minor due the separation of ash-particle and sulfur dioxide plumes shortly after the eruption. The volcanic material had very little effect on PM1 mass concentrations or sub-micron particle number size distributions in the Helsinki area. The aerosol scattering coefficient was increased and visibility was slightly decreased during the episode, but in general changes in aerosol optical properties due to volcanic aerosols seem to be difficult to be distinguished from those induced by other pollutants present in a continental boundary layer. The case investigated here demonstrates clearly the power of combining surface aerosol measurements, dispersion model simulations and satellite measurements in analyzing surface air pollution episodes caused by volcanic eruptions. None of these three approaches alone would be sufficient to forecast, or even to unambiguously identify, such episodes.
Effects of water discharge and sediment load on evolution of modern Yellow River Delta, China, over the period from 1976 to 2009
Authors: Yu J. , Fu Y. , Li Y. , Han G. , Wang Y. , Zhou D. , Sun W. , Gao Y. , Meixner F. X.
Published: September 2011

Abstract. The Yellow River, which is the second largest river in China, is regarded as the world's largest contributor of fluvial sediment load to the ocean. In recent decades, the dramatic reduction in water discharge and sediment load due to climate change and human activities in the drainage basin has greatly constrained the evolution process of Yellow River delta. We highlight how runoff and sediment load discharged into sea affected extension of shoreline length and area of modern Yellow River delta during 1976–2009 based on remote sensing interpretation and long-term monitoring data in hydrological station. Average runoff of 207.47 × 108 m3 yr−1 and average sediment load of 4.63 × 108 m3 yr−1 were discharged into the sea from 1976 to 2008. The annual runoff reduced by ~59.7 % in 1990–2002 and annual sediment load reduction up to ~72.1 % in 2003–2008. Both shoreline length and area of Yellow River Delta extended overall in the studied period, but with decreasing rates in accordance with changes of runoff and sediment load. High increasing rate of shoreline length of ~3.63 km yr−1 and quick area extension of ~16.26 km2 yr−1 were observed in 1976–1985. Since 1996 however, the average increase rate of shoreline length and area decreased to ~0.80 km yr−1 and ~3.94 km2 yr−1, respectively. In addition, the fluctuated changes of shoreline and area were great and the net negative increase of land area was occurred during this period. There exist significant exponential relationships between the accumulated sediment load and extensions of shoreline length and the area during the evolution of the modern Yellow River Delta. Our results indicate that the evolution of shoreline and change of area of the Yellow River Delta are directly affected by the dramatic reduction of runoff and sediment load, which are much close related human being activities in Yellow River drainage basin in recent decades.
Characterization of turbulence and validation of fine-scale parametrization in the Mediterranean Sea during BOUM experiment
Authors: Cuypers Y. , Bouruet-Aubertot P. , Marec C. , Fuda J.-L.
Published: September 2011

Abstract. One main purpose of BOUM experiment was to give evidence of the possible impact of submesoscale dynamics on biogeochemical cycles. To this aim physical as well as biogeochemical data were collected along a zonal transect through the western and eastern basins. Along this transect 3 day fixed point stations were performed within anticyclonic eddies during which microstructure measurements were collected over the first 100 m. We focus here on the characterization of turbulent mixing induced by internal wave breaking. The analysis of microstructure measurements revealed a high level of turbulence in the seasonal pycnocline and a moderate level below with energy dissipation mean values of the order of 10−6 W kg−1 and 10−8 W kg−1, respectively. Fine-scale parameterizations developed to mimic energy dissipation produced by internal wavebreaking were then tested against these direct measurements. Once validated a parameterization has been applied to infer energy dissipation and mixing over the whole data set, thus providing an overview over a latitudinal section of the Mediterranean sea. The results evidence a significant increase of dissipation at the top and base of eddies associated with strong near inertial waves. Vertical turbulent diffusivity is increased both in these regions and in the weakly stratified eddy core.
Observations of the altitude of the volcanic plume during the eruption of Eyjafjallajökull, April–May 2010
Authors: Arason P. , Petersen G. N. , Bjornsson H.
Published: September 2011

Abstract. The eruption of Eyjafjallajökull volcano in 2010 lasted for 39 days, 14 April–23 May. The eruption had two explosive phases separated by a phase with lava formation and reduced explosive activity. The height of the plume was monitored every 5 min with a C-band weather radar located in Keflavík International Airport, 155 km distance from the volcano. Furthermore, several web cameras were mounted with a view of the volcano, and their images saved every five seconds. Time series of the plume-top altitude were constructed from the radar observations and images from a web camera located in the village Hvolsvöllur at 34 km distance from the volcano. This paper presents the independent radar and web camera time series and performs cross validation. The results show good agreement between the time series for the range when both series are available. However, while the radar altitudes are semi-discrete the data availability was much higher than for the web camera, indicating how essential weather radars are as eruption plume monitoring devices. The echo top radar series of the altitude of the volcanic plume are publicly available from the Pangaea Data Publisher (http://dx.doi.org/10.1594/PANGAEA.760690).
Identification of dynamical transitions in marine palaeoclimate records by recurrence network analysis
Authors: Donges J. F. , Donner R. V. , Rehfeld K. , Marwan N. , Trauth M. H. , Kurths J.
Published: September 2011

Abstract. The analysis of palaeoclimate time series is usually affected by severe methodological problems, resulting primarily from non-equidistant sampling and uncertain age models. As an alternative to existing methods of time series analysis, in this paper we argue that the statistical properties of recurrence networks – a recently developed approach – are promising candidates for characterising the system's nonlinear dynamics and quantifying structural changes in its reconstructed phase space as time evolves. In a first order approximation, the results of recurrence network analysis are invariant to changes in the age model and are not directly affected by non-equidistant sampling of the data. Specifically, we investigate the behaviour of recurrence network measures for both paradigmatic model systems with non-stationary parameters and four marine records of long-term palaeoclimate variations. We show that the obtained results are qualitatively robust under changes of the relevant parameters of our method, including detrending, size of the running window used for analysis, and embedding delay. We demonstrate that recurrence network analysis is able to detect relevant regime shifts in synthetic data as well as in problematic geoscientific time series. This suggests its application as a general exploratory tool of time series analysis complementing existing methods.
The Advancement of Biomarker-Based Diagnostic Tools for Ovarian, Breast, and Pancreatic Cancer through the Use of Urine as an Analytical Biofluid
Authors: Nolen Brian M. , Lokshin Anna E.
Published: September 2011

Despite considerable advancements, the development of effective cancer screening tools based on serum biomarker measurements has thus far failed to achieve a meaningful clinical impact. The incremental progress observed over the course of serum biomarker development suggests that further refinements based on novel approaches may yet result in a breakthrough. The use of urine as an analytical biofluid for biomarker development may represent such an approach. The unique characteristics of urine including a high level of stability, ease of sampling, and an inactive and low-complexity testing matrix offer several potential advantages over the use of serum. A number of recent reports have demonstrated the utility of urine in the identification of novel cancer biomarkers and also the improved performance of biomarkers previously evaluated in serum. In this review, advancements related to the use of urine biomarkers within the settings of ovarian, breast, and pancreatic cancer are presented and discussed. Findings regarding the identification of specific urine biomarkers for each disease are highlighted along with comparative analyses of urine and serum biomarkers as diagnostic tools.
Biomarkers in Malignant Mesothelioma: Diagnostic and Prognostic Role of Soluble Mesothelin-Related Peptide
Authors: Dipalma Nicola , Luisi Vito , Di Serio Francesca , Fontana Antonietta , Maggiolini Piera , Licchelli Brunella , Mera Ernesto , Bisceglia Lucia , Galise Ida , Loizzi Michele , Pizzigallo Maria Annunziata , Molinini Raffaele , Vimercati Luigi
Published: September 2011

Soluble mesothelin-related peptide (SMRP) is a biomarker that has been proposed for differential diagnosis from pleural metastatic cancer, as well as prognosis and treatment monitoring of malignant pleural mesothelioma (MM). The aim of this study was to evaluate the role of SMRP in clinic management of MM. We assayed the SMRP concentrations in 354 subjects: 109 healthy volunteers with no history of exposure to asbestos, 26 patients with previous occupational asbestos exposure but who were free from pleural or parenchymal disease, 48 patients with asbestosis, 110 patients with pleural plaques, 25 patients with lung cancer, and 36 patients with MM. We also tested SMRP titers in 2 patients with MM at 5 different times of the disease, to evaluate the trend of the biomarker in the course of therapy. Our data confirm previous experiences with the use of SMRP as a diagnostic marker of MM. Low SMRP levels at diagnosis seem to have a positive prognostic significance.
Bone Engineering with Porous Ceramics and Metals
Authors: Luyten Jan , Thijs Ivo , Ravelingien Matthieu , Mullens Steven
Published: September 2011

The self‐healing capacity of bone for the reconstruction of small fractures is widely recognized. However, large bone defects still pose a big challenge for orthopedic surgeons. Tissue engineering using porous scaffolds is a new trend to solve this problem and to speed the healing process. When seeded with human cells and bone growth stimulating molecules, they enhance bone healing. Such porous supports try to mimic the properties of trabecular bone. The needed structural properties are: a high and interconnected porosity, pore sizes in the range of 100–500 µm, mechanical properties comparable to trabecular bone and a microporous surface to allow further coating, cell attachment and seeding. Starting from these requirements, it is clear that a cellular material has the ideal architecture for such biomedical scaffold. Polymeric, ceramic or metallic foam structures can be obtained by different manufacturing routes. In our group we optimized three methods, all starting from a powder suspension. They are the PU template technique, gelcasting and the 3D fiber deposition (3DFD) method. Ti and Ti–6Al–4V scaffolds produced by gelcasting and 3DFD can mimic the structural and mechanical properties of the trabecular bone. Hydroxyapatite (HA) and mixtures of hydroxyapatite and beta tricalcium phosphate (β‐TCP) were tested for their rate of dissolution in simulated body fluid (SBF) and for their strength as function of their composition. Recently, it was proven that magnesium is a biocompatible and bio‐absorbable material. Therefore, as a metallic scaffold it can be expected that it can fulfill both functions of the biomedical scaffold: to be load‐bearing and to be bio‐absorbable. Nevertheless, the realization of this ideal scaffold needs much more fundamental research. Some preliminary synthesis tests for producing porous Mg‐scaffolds are given in this contribution.
Molecular Basis of Chiral Acid Recognition by Candida rugosa Lipase: X‐Ray Structure of Transition State Analog and Modeling of the Hydrolysis of Methyl 2‐Methoxy‐2‐phenylacetate
Authors: Colton Ian J. , Yin DeLu (Tyler) , Grochulski Pawel , Kazlauskas Romas J.
Published: September 2011

Lipase from Candida rugosa shows high enantioselectivity toward α‐substituted chiral acids such as 2‐arylpropionic acids. To understand how Candida rugosa lipase (CRL) distinguishes between enantiomers of chiral acids, we determined the X‐ray crystal structure of a transition‐state analog covalently linked to CRL. CRL shows moderate enantioselectivity (E=23) toward methyl 2‐methoxy‐2‐phenylacetate, 1‐methyl ester, favoring the (S)‐enantiomer. We synthesized phosphonate (RC,RPSP)‐3, which, upon reaction with CRL, mimics the transition state for hydrolysis of (S)‐1‐methyl ester, the fast‐reacting enantiomer. An X‐ray crystal structure of this complex shows a catalytically productive orientation with the phenyl ring in the hydrophobic tunnel of the lipase. Phe345 crowds the region near the substrate stereocenter. Computer modeling of the slow‐reacting enantiomer examined four possible conformations for the corresponding slow‐reacting enantiomer: three conformations where two substituents at the stereocenter have been exchanged relative to the fast‐reacting enantiomer and one conformation with an umbrella‐like inversion orientation. Each of these orientations disrupts the orientation of the catalytic histidine, but the molecular basis for disruption differs in each case showing that multiple mechanisms are required for high enantioselectivity.
G‐PKDrep‐live, a genetically encoded FRET reporter to measure PKD activity at the trans‐Golgi‐network
Authors: Eisler Stephan A. , Fuchs Yannick F. , Pfizenmaier Klaus , Hausser Angelika
Published: September 2011

The serine/threonine protein kinase D (PKD) is recruited to the trans‐Golgi‐network (TGN) by interaction with diacylglycerol (DAG) and Arf1 and promotes the fission of vesicles containing cargo destined for the plasma membrane. PKD activation is mediated by PKC(‐induced phosphorylation. However, signaling pathways that activate PKD specifically at the TGN are only poorly characterized. Recently we created G‐PKDrep, a genetically encoded fluorescent reporter for PKD activity at the TGN in fixed cells. To establish a reporter useful for monitoring Golgi‐specific PKD activity in living cells we now refined G‐PKDrep to generate G‐PKDrep‐live. Specifically, phosphorylation of G‐PKDrep‐live expressed in mammalian cells results in changes of fluorescence resonance energy transfer (FRET), and allows for indirect imaging of PKD activity. In a proof‐of‐principle experiment using phorbolester treatment, we demonstrate the reporter's capability to track rapid activation of PKD at the TGN. Furthermore, activation‐induced FRET changes are reversed by treatment with PKD‐specific pharmacological inhibitors. Thus, the newly developed reporter G‐PKDrep‐live is a suitable tool to visualize dynamic changes in PKD activity at the TGN in living cells.

See accompanying commentary by Gautam DOI: 10.1002/biot.201100424
Bond Stretching and Redox Behavior in Coinage Metal Complexes of the Dichalcogenide Dianions [(SPh2P)2CEEC(PPh2S)2]2− (E=S, Se): Diradical Character of the Dinuclear Copper(I) Complex (E=S)
Authors: Konu Jari , Chivers Tristram , Tuononen Heikki M.
Published: September 2011

The metathetical reactions of a) [Li(tmeda)]2[(S)C(PPh2S)2] (Li2⋅3 c) with CuCl2 and b) [Li(tmeda)]2[(SPh2P)2CSSC(PPh2S)2] (Li2⋅4 c) with two equivalents of CuCl both afford the binuclear CuI complex {Cu2[(SPh2P)2CSSC(PPh2S)2]} (5 c). The elongated (C)SS(C) bond (ca. 2.54 and 2.72 Å) of the dianionic ligand observed in the solid‐state structure of 5 c indicate the presence of diradical character as supported by theoretical analyses. The treatment of [Li(tmeda)]2[(SPh2P)2CSeSeC(PPh2S)2] (Li2⋅4 b) and Li2⋅4 c with AgOSO2CF3 produce the analogous AgI derivatives, {Ag2[(SPh2P)2CEEC(PPh2S)2]} (6 b, E=Se; 6 c, E=S), respectively. The diselenide complex 6 b exhibits notably weaker AgSe(C) bonds than the corresponding contacts in the CuI congeners, and the 31P NMR data suggest a possible isomerization in solution. In contrast to the metathesis observed for CuI and AgI reagents, the reactions of Li2⋅4 b and Li2⋅4 c with Au(CO)Cl involve a redox process in which the dimeric dichalcogenide ligands are reduced to the corresponding monomeric dianions, [(E)C(PPh2S)2]2− (3 b, E=Se; 3 c, E=S), and one of the gold centers is oxidized to generate the mixed‐valent AuI/AuIII complexes, {Au[(E)C(PPh2S)2]}2 (7 b, E=Se; 7 c, E=S), with relatively strong aurophilic AuI⋅⋅⋅AuIII interactions. The new compounds 5 c, 6 b,c and 7 b,c are characterized in solution by NMR spectroscopy and in the solid state by X‐ray crystallography (5 c, 6 b, 7 b and 7 c) and by Raman spectroscopy (5 c and 6 c). The UV‐visible spectra of coinage metal complexes of the type 5, 6 and 7 are discussed in the light of results from theoretical analyses using time‐dependent density functional theory.
On the Determination of the Stereochemistry of Semisynthetic Natural Product Analogues using Chiroptical Spectroscopy: Desulfurization of Epidithiodioxopiperazine Fungal Metabolites
Authors: Cherblanc Fanny , Lo Ya‐Pei , De Gussem Ewoud , Alcazar‐Fuoli Laura , Bignell Elaine , He Yanan , Chapman‐Rothe Nadine , Bultinck Patrick , Herrebout Wouter A. , Brown Robert , Rzepa Henry S. , Fuchter Matthew J.
Published: September 2011

Isolation and semisynthetic modification of the fungal metabolite chaetocin gave access to a desulfurized analogue of this natural product. Detailed chiroptical studies, comparing experimentally obtained optical rotation values, electronic circular dichroism spectra, and vibrational circular dichroism spectra to computationally simulated ones, reveal the desulfurization of chaetocin to unambiguously proceed with retention of configuration. Consideration of the plausible mechanisms for this process highlighted inconsistencies in the stereochemical assignment of related molecules in the literature. This in turn allowed the stereochemical reassignment of the natural product analogue dethiodehydrogliotoxin.
Updating a chiral separation strategy for non‐acidic drugs with capillary electrochromatography applicable for both chlorinated and non‐chlorinated polysaccharide selectors
Authors: Hendrickx Ans , Mangelings Debby , Chankvetadze Bezhan , Vander Heyden Yvan
Published: September 2011

A generic strategy for the chiral separation of non‐acidic pharmaceuticals was updated to complete an approach defined earlier. The selected chiral stationary phases are all polysaccharide selectors, chlorinated, and non‐chlorinated, namely Lux® Amylose 2, Chiralcel® OD‐RH, Lux® Cellulose 4, and Chiralpak® AD‐RH. In this study, the screening step of a strategy defined earlier was updated and the optimization steps were re‐evaluated for the applied chiral stationary phases. These screening and optimization conditions were studied by analyzing 20 pharmaceuticals at different organic modifier contents, temperatures, or applied voltages. The proposed chiral separation strategy was then evaluated with a test set of 19 non‐acidic drugs. Seventeen compounds (89.5%) of the latter set could be resolved of which eight (42%) were baseline separated. The strategy thus proved to be applicable on compounds different from those used for its development.
Symptoms of Eating Disorders, Drive for Muscularity and Physical Activity Among Norwegian Adolescents
Authors: Bratland‐Sanda Solfrid , Sundgot‐Borgen Jorunn
Published: September 2011

Purpose

The aim of this study was to examine symptoms of eating disorders (ED), drive for muscularity and physical activity in a Norwegian adolescent population.

Methods

A total of 722 adolescents aged 12–18 years (response rate: 83%) filled out a questionnaire containing the Drive for Muscularity Scale, Eating Disorders Inventory subscales Drive for Thinness (EDI‐DT), Body Dissatisfaction (EDI‐BD) and Bulimia (EDI‐B), and questions about amount of and motives for physical activity.

Results

Eating Disorders Inventory subscale scores were higher, and Drive for Muscularity Scale Score (DMS) scores were lower among girls compared with boys. EDI and DMS were correlated with motives for, but not amount of, physical activity. EDI and DMS were associated in boys, not girls.

Discussion

The associations between EDI and DMS among boys call for a wider approach when examining ED among boys. Copyright © 2011 John Wiley & Sons, Ltd and Eating Disorders Association.
Improved understanding of tributyltin sorption on natural and biochar-amended sediments
Authors: Xiao Xiaoyu , Sheng G. Daniel , Qiu Yuping
Published: September 2011

A poor understanding of tributyltin (TBT) sorption on sediments has hindered an accurate evaluation of its environmental fate. The present study determined TBT sorption by a freshwater sediment (BH) and a coastal marine sediment (TZ) as influenced by pH, salinity, and biochar (BC) amendment into TZ. The isotherms were essentially linear, with KOC values in the range of 104 to 105 L/kg. Tributyltin sorption at pH 3.56 and 8.00 occurred mainly via partitioning. It reached maxima at pH equal to its pKa (=6.25) because of added ion exchange. A salinity increase from 5 to 35 practical salinity units enhanced TBT sorption at pH 3.56 and 8.00 on TZ by approximately 30% and on BH by approximately 80%, ascribed to the salting-out effect that reduced the solubilities of tributyltin hydroxide (TBTOH) and tributyltin chloride (TBTCl). At pH 6.25, the same salinity increase reduced TBT sorption on TZ by approximately 20% but enhanced TBT sorption on BH by approximately 35%. This was attributed to the enhancing role of salting out and the reducing role of metal competition for ion exchange. Tributyltin was two orders of magnitude more effectively sorbed by BC than by total organic carbon of TZ, mainly because of the high level of surface area of the BC. Although BC affinity for TBT may be significantly diminished when present in TZ, it was considered to be the primary contributor to TBT sorption from water. Biochar may thus be used to immobilize TBT in sediment for potential remediation. Environ. Toxicol. Chem. 2011;30:2682–2687. © 2011 SETAC