bluuebunny/crossref_metadata_2025 huggingface dataset:
Cutting Edge: Regulatory T Cells Selectively Attenuate, Not Terminate, T Cell Signaling by Disrupting NF-κB Nuclear Accumulation in CD4 T Cells
Authors: Huang Yu-Hui , Sojka Dorothy K. , Fowell Deborah J.
Published: January 2012

A key consequence of regulatory T cell (Treg) suppression of CD4 T cells is the inhibition of IL-2 production, yet how Tregs attenuate IL-2 has not been defined. Current models predict a termination of TCR signaling, by disrupting T–APC contacts, or TCR signal modification, through mechanisms such as cAMP. To directly define Treg effects on TCR signaling in CD4 T cell targets, we visualized changes in nuclear accumulation of transcription factors at time points when IL-2 was actively suppressed. Nuclear accumulation of NFAT was highly dependent on sustained TCR signaling in the targets. However, in the presence of Tregs, NFAT and AP-1 signals were sustained in the target cells. In contrast, NF-κB p65 was selectively attenuated. Thus, Tregs do not generally terminate TCR signals. Rather, Tregs selectively modulate TCR signals within hours of contact with CD4 targets, independent of APCs, resulting in the specific loss of NF-κB p65 signals.
A high-resolution emission inventory of primary pollutants for the Huabei region, China
Authors: Zhao B. , Wang P. , Ma J. Z. , Zhu S. , Pozzer A. , Li W.
Published: January 2012

Abstract. Huabei, located between 32° N and 42° N, is part of eastern China and includes administratively the Beijing and Tianjin Municipalities, Hebei and Shanxi Provinces, and Inner-Mongolia Autonomous Region. Over the past decades, the region has experienced dramatic changes in air quality and climate, and has become a major focus of environmental research in China. Here we present a new inventory of air pollutant emissions in Huabei for the year 2003 developed as part of the project Influence of Pollution on Aerosols and Cloud Microphysics in North China (IPAC-NC). Our estimates are based on data from the statistical yearbooks of the state, provinces and local districts, including major sectors and activities of power generation, industrial energy consumption, industrial processing, civil energy consumption, crop straw burning, oil and solvent evaporation, manure, and motor vehicles. The emission factors are selected from a variety of literature and those from local measurements in China are used whenever available. The estimated total emissions in the Huabei administrative region in 2003 are 4.73 Tg SO2, 2.72 Tg NOx (in equivalent NO2), 1.77 Tg VOC, 24.14 Tg CO, 2.03 Tg NH3, 4.57 Tg PM10, 2.42 Tg PM2.5, 0.21 Tg EC, and 0.46 Tg OC. For model convenience, we consider a larger Huabei region with Shandong, Henan and Liaoning Provinces included in our inventory. The estimated total emissions in the larger Huabei region in 2003 are: 9.55 Tg SO2, 5.27 Tg NOx (in equivalent NO2), 3.82 Tg VOC, 46.59 Tg CO, 5.36 Tg NH3, 10.74 Tg PM10, 5.62 Tg PM2.5, 0.41 Tg EC, and 0.99 Tg OC. The estimated emission rates are projected into grid cells at a horizontal resolution of 0.1° latitude by 0.1° longitude. Our gridded emission inventory consists of area sources, which are classified into industrial, civil, traffic, and straw burning sectors, and large industrial point sources, which include 345 sets of power plants, iron and steel plants, cement plants, and chemical plants. The estimated regional NO2 emissions are about 2–3% (administrative Huabei region) or 5% (larger Huabei region) of the global anthropogenic NO2 emissions. We compare our inventory (IPAC-NC) with the global emission inventory EDGAR-CIRCE and the Asian emission inventory INTEX-B. Except for a factor of 3 lower EC emission rate in comparison with INTEX-B, the biases of the total emissions of most primary air pollutants in Huabei estimated in our inventory, with respect to EDGAR-CIRCE and INTEX-B, generally range from −30% to +40%. Large differences up to a factor of 2–3 for local emissions in some areas (e.g. Beijing and Tianjin) are found. It is recommended that the inventories based on the activity rates and emission factors for each specific year should be applied in future modeling work related to the changes in air quality and atmospheric chemistry over this region.
Bulk microphysical properties of semi-transparent cirrus from AIRS: a six year global climatology and statistical analysis in synergy with geometrical profiling data from CloudSat-CALIPSO
Authors: Guignard A. , Stubenrauch C. J. , Baran A. J. , Armante R.
Published: January 2012

Abstract. This article presents a retrieval method and a statistical analysis of the bulk microphysical properties of semi-transparent ice clouds using the Atmospheric Infrared Sounder (AIRS). The method relies on spectral differences of cirrus emissivities in the 8–12 μm range and is sensitive to the effective ice crystal diameter (De) and ice water path (IWP) of up to 85 μm and 120 g m−2, respectively. An indication of the most frequent ice crystal habit in the cirrus has been obtained by using separately single scattering properties of column-like and aggregate-like ice crystals in the simulations. Uncertainties due to hypotheses on atmospheric parameters and ice crystal single scattering properties are discussed and the cirrus emissivity and temperature range for the applicability of the method are determined. To be sure that the cirrus only includes ice crystals, one has to restrict the cloud temperature range to Tcld<230 K. On a global scale, these semi-transparent ice clouds (cirrus) represent about 25% of all high clouds and are mainly encountered in the midlatitudes during winter and in the tropics, with an average De and IWP of 52 μm and 27 g m−2, respectively. A comparison with bulk microphysical properties from the TIROS-N Operational Vertical Sounder (TOVS) shows an agreement on global mean values. The addition of spectral information revealed improvements at the limits of the cirrus emissivity range. Collocated Radar-Lidar Geometrical Profiling (GEOPROF) data have been used to study the vertical structure of these clouds and to infer average ice water content (IWC) for cirrus with a small vertical extent. This allowed us to compare and contrast parameterizations of De as functions of IWC and IWP, respectively.
ANISORROPIA: the adjoint of the aerosol thermodynamic model ISORROPIA
Authors: Capps S. L. , Henze D. K. , Hakami A. , Russell A. G. , Nenes A.
Published: January 2012

Abstract. We present the development of ANISORROPIA, the discrete adjoint of the ISORROPIA thermodynamic equilibrium model that treats the Na+-SO42−- HSO4−-NH4+ -NO3−-Cl−-H2O aerosol system, and we demonstrate its sensitivity analysis capabilities. ANISORROPIA calculates sensitivities of an inorganic species in aerosol or gas phase with respect to the total concentrations of each species present with less than a two-fold increase in computational time over the concentration calculations. Due to the highly nonlinear and discontinuous solution surface of ISORROPIA, evaluation of the adjoint required a new, complex-variable version of the model, which determines first-order sensitivities with machine precision and avoids cancellation errors arising from finite difference calculations. The adjoint is verified over an atmospherically relevant range of concentrations, temperature, and relative humidity. We apply ANISORROPIA to recent field campaign results from Atlanta, GA, USA, and Mexico City, Mexico, to characterize the inorganic aerosol sensitivities of these distinct urban air masses. The variability in the relationship between fine mode inorganic aerosol mass and precursor concentrations shown has important implications for air quality and climate.
Wet and dry deposition of atmospheric nitrogen at ten sites in Northern China
Authors: Pan Y. P. , Wang Y. S. , Tang G. Q. , Wu D.
Published: January 2012

Abstract. Emissions of reactive nitrogen (N) species can affect surrounding ecosystems via atmospheric deposition. However, few long-term and multi-site measurements have focused on both the wet and the dry deposition of individual N species in large areas of Northern China. Thus, the magnitude of atmospheric deposition of various N species in Northern China remains uncertain. In this study, the wet and dry atmospheric deposition of different N species was investigated during a three-year observation campaign at ten selected sites in Northern China. The results indicate that N deposition levels in Northern China were high with a ten-site, three-year average of 60.6 kg N ha−1 yr−1. The deposition levels showed spatial and temporal variation in the range of 28.5–100.4 kg N ha−1 yr−1. Of the annual total deposition, 40% was deposited via precipitation, and the remaining 60% was comprised of dry-deposited forms. Compared with gaseous N species, particulate N species were not the major contributor of dry-deposited N; they contributed approximately 10% to the total flux. On an annual basis, oxidized species accounted for 21% of total N deposition, thereby implying that other forms of gaseous N, such as NH3, comprised a dominant portion of the total flux. The contribution of NO3− to N deposition was enhanced in certain urban and industrial areas. As expected, the total N deposition in Northern China was significantly larger than the values reported by national scale monitoring networks in Europe, North America and East Asia because of high rates of wet deposition and gaseous NH3 dry deposition. The results have three important implications. First, atmospheric N deposition in Northern China falls within the range of critical loads for temperate forests and grasslands, a threshold above which harmful ecological effects to specified parts of temperate ecosystems often occur. Second, the magnitude, patterns and forms of N deposition will help to inform simulated N addition experiments, which are used to evaluate ecological impacts on receiving ecosystems. Third, the field-based evidence in this unique deposition dataset validates emission inventories of reactive N species and will help policy-makers control atmospheric pollution. Taken together, these findings show that NH3 emissions should be abated to mitigate high N deposition and associated potential impacts on ecosystems in Northern China.
Observational constraints on entrainment and the entrainment interface layer in stratocumulus
Authors: Carman J. K. , Rossiter D. L. , Khelif D. , Jonsson H. H. , Faloona I. C. , Chuang P. Y.
Published: January 2012

Abstract. Aircraft sampling of the stratocumulus-topped boundary layer (STBL) during the Physics of Stratocumulus Top (POST) experiment was primarily achieved using sawtooth flight patterns, during which the atmospheric layer 100 m above and below cloud top was sampled at a frequency of once every 2 min. The large data set that resulted from each of the 16 flights document the complex structure and variability of this interfacial region in a variety of conditions. In this study, we first describe some properties of the entrainment interface layer (EIL), where strong gradients in turbulent kinetic energy (TKE), potential temperature and moisture can be found. We find that defining the EIL by the first two properties tend to yield similar results, but that moisture can be a misleading tracer of the EIL. These results are consistent with studies using large-eddy simulations. We next utilize the POST data to shed light on and constrain processes relevant to entrainment, a key process in the evolution of the STBL that to-date is not well-represented even by high resolution models. We define "entrainment efficiency" as the ratio of the TKE consumed by entrainment to that generated within the STBL (primarily by cloud-top cooling). We find values for the entrainment efficiency that vary by 1.5 orders of magnitude, which is even greater than the one order magnitude that previous modeling results have suggested. Our analysis also demonstrate that the entrainment efficiency depends on the strength of the stratification of the EIL, but not on the TKE in the cloud top region. The relationships between entrainment efficiency and other STBL parameters serve as novel observational contraints for simulations of entrainment in such systems.
Emissions halted of the potent greenhouse gas SF5CF3
Authors: Sturges W. T. , Oram D. E. , Laube J. C. , Reeves C. E. , Newland M. J. , Hogan C. , Martinerie P. , Witrant E. , Brenninkmeijer C. A. M. , Schuck T. J. , Fraser P. J.
Published: January 2012

Abstract. Long term measurements in background air (Cape Grim, Tasmania) and firn air (NEEM, Greenland) of the "super" greenhouse gas SF5CF3 show that emissions declined after the late 1990s, having grown since the 1950s, and became indistinguishable from zero after 2003. It is concluded that this is due to the cessation of global production of perfluorooctyl sulfonate-based fluorochemicals. An earlier observation of closely correlated atmospheric abundances of SF5CF3 and SF6 are shown here to have likely been purely coincidental, as their respective trends diverged after 2002. Due to its long lifetime (ca. 900 yr), atmospheric concentrations of SF5CF3 have not declined, and it is now well mixed between hemispheres, as is also shown here from interhemispheric aircraft measurements. Total cumulative emissions of SF5CF3 amount to around 5 kT.
Aerosol classification using airborne High Spectral Resolution Lidar measurements – methodology and examples
Authors: Burton S. P. , Ferrare R. A. , Hostetler C. A. , Hair J. W. , Rogers R. R. , Obland M. D. , Butler C. F. , Cook A. L. , Harper D. B. , Froyd K. D.
Published: January 2012

Abstract. The NASA Langley Research Center (LaRC) airborne High Spectral Resolution Lidar (HSRL) on the NASA B200 aircraft has acquired extensive datasets of aerosol extinction (532 nm), aerosol optical depth (AOD) (532 nm), backscatter (532 and 1064 nm), and depolarization (532 and 1064 nm) profiles during 18 field missions that have been conducted over North America since 2006. The lidar measurements of aerosol intensive parameters (lidar ratio, depolarization, backscatter color ratio, and spectral depolarization ratio) are shown to vary with location and aerosol type. A methodology based on observations of known aerosol types is used to qualitatively classify the extensive set of HSRL aerosol measurements into eight separate types. Several examples are presented showing how the aerosol intensive parameters vary with aerosol type and how these aerosols are classified according to this new methodology. The HSRL-based classification reveals vertical variability of aerosol types during the NASA ARCTAS field experiment conducted over Alaska and northwest Canada during 2008. In two examples derived from flights conducted during ARCTAS, the HSRL classification of biomass burning smoke is shown to be consistent with aerosol types derived from coincident airborne in situ measurements of particle size and composition. The HSRL retrievals of AOD and inferences of aerosol types are used to apportion AOD to aerosol type; results of this analysis are shown for several experiments.
PHOCUS radiometer
Authors: Nyström O. , Murtagh D. , Belitsky V.
Published: January 2012

Abstract. PHOCUS – Particles, Hydrogen and Oxygen Chemistry in the Upper Summer Mesosphere is a Swedish sounding rocket experiment, launched in July 2011, with the main goal of investigating the upper atmosphere in the altitude range 50–110 km. This paper describes the SondRad instrument in the PHOCUS payload, the radiometer comprising two frequency channels, 183 GHz and 557 GHz, aimed at exploring the water vapour concentration distribution in connection with the appearance of noctilucent (night shining) clouds. The design of the radiometer system has been done in a collaboration between Omnisys Instruments AB and the Group for Advanced Receiver Development (GARD) at Chalmers University of Technology where Omnisys was responsible for the overall design, implementation, and verification of the radiometers and backend whereas GARD was responsible for the radiometer optics and calibration systems. The SondRad instrument covers the water absorption lines at 183 GHz and 557 GHz. The 183 GHz channel is a side-looking radiometer while the 557 GHz radiometer is placed along the rocket axis looking in the forward direction. Both channels employ sub-harmonically pumped Schottky mixers and FFT spectrometer backends with 67 kHz resolution. The radiometers include novel calibration systems specifically adjusted for use with each frequency channel. The 183 GHz channel employs a CW-pilot signal calibrating the entire receiving chain while the IF-chain of the 557 GHz channel is calibrated by injecting a signal from a reference noise source through a directional coupler. The instrument collected complete spectra for both the 183 GHz and the 557 GHz with 300 Hz data rate for the 183 GHz channel and 10 Hz data rate for the 557 GHz channel for about 60 s reaching the apogee of the flight trajectory and 100 s after that. With lossless data compression using variable resolution over the spectrum, the data set was reduced to 2 × 12 MByte. The first results indicate that the instrument has successfully performed measurements of the mesospheric water profile as planned. However, the temperature environment for the instruments showed more extreme behaviour than expected and accounted for. Consequently the results of the calibration and the final data reduction will need careful treatment. Further, simulations through FEM modelling and direct measurements of the simulated thermal environment and its impact on the instrument performance are described, as well as suggestions for improvements in the design for future flights.
New Aura Microwave Limb Sounder observations of BrO and implications for Bry
Authors: Millán L. , Livesey N. , Read W. , Froidevaux L. , Kinnison D. , Harwood R. , MacKenzie I. A. , Chipperfield M. P.
Published: January 2012

Abstract. This paper introduces a new inversion algorithm for retrievals of stratospheric BrO from the Aura Microwave Limb Sounder. This version is based on the algorithm described by Livesey et al. (2006a) but designed to reduce a large bias presented in the previous MLS BrO datasets in the lower stratosphere and, therefore, to increase its useable pressure range. In this new version, vertical profiles of BrO were obtained in the 100 to 4.6 hPa pressure range extending the lower altitude limit of the MLS retrievals. A description of the retrieval methodology and an error analysis are presented. Single daily profile precision, when taking the ascending-descending (day-night) difference, was found to be up to 40 pptv while systematic error biases were estimated to be less than about 3 pptv. Monthly mean comparisons show broad agreement with other measurements as well as with state-of-the-art numerical models. We infer total inorganic Bry using the measured MLS BrO to be 20.3 ± 4.5 pptv, which implies a contribution from Very Short Lived Substances to the stratospheric bromine budget of ∼5 ± 4.5 pptv.
Climate variability in Andalusia (southern Spain) during the period 1701–1850 based on documentary sources: evaluation and comparison with climate model simulations
Authors: Rodrigo F. S. , Gómez-Navarro J. J. , Montávez Gómez J. P.
Published: January 2012

Abstract. In this work, a reconstruction of climatic conditions in Andalusia (southern Iberian Peninsula) during the period 1701–1850, as well as an evaluation of its associated uncertainties, is presented. This period is interesting because it is characterized by a minimum in solar irradiance (Dalton Minimum, around 1800), as well as intense volcanic activity (for instance, the eruption of Tambora in 1815), at a time when any increase in atmospheric CO2 concentrations was of minor importance. The reconstruction is based on the analysis of a wide variety of documentary data. The reconstruction methodology is based on counting the number of extreme events in the past, and inferring mean value and standard deviation using the assumption of normal distribution for the seasonal means of climate variables. This reconstruction methodology is tested within the pseudoreality of a high-resolution paleoclimate simulation performed with the regional climate model MM5 coupled to the global model ECHO-G. The results show that the reconstructions are influenced by the reference period chosen and the threshold values used to define extreme values. This creates uncertainties which are assessed within the context of climate simulation. An ensemble of reconstructions was obtained using two different reference periods (1885–1915 and 1960–1990) and two pairs of percentiles as threshold values (10–90 and 25–75). The results correspond to winter temperature, and winter, spring and autumn rainfall, and they are compared with simulations of the climate model for the considered period. The mean value of winter temperature for the period 1781–1850 was 10.6 ± 0.1 °C (11.0 °C for the reference period 1960–1990). The mean value of winter rainfall for the period 1701–1850 was 267 ± 18 mm (224 mm for 1960–1990). The mean values of spring and autumn rainfall were 164 ± 11 and 194 ± 16 mm (129 and 162 mm for 1960–1990, respectively). Comparison of the distribution functions corresponding to 1790–1820 and 1960–1990 indicates that during the Dalton Minimum the frequency of dry and warm (wet and cold) winters was lower (higher) than during the reference period: temperatures were up to 0.5 °C lower than the 1960–1990 value, and rainfall was 4% higher.
Benchmarking homogenization algorithms for monthly data
Authors: Venema V. K. C. , Mestre O. , Aguilar E. , Auer I. , Guijarro J. A. , Domonkos P. , Vertacnik G. , Szentimrey T. , Stepanek P. , Zahradnicek P. , Viarre J. , Müller-Westermeier G. , Lakatos M. , Williams C. N. , Menne M. J. , Lindau R. , Rasol D. , Rustemeier E. , Kolokythas K. , Marinova T. , Andresen L. , Acquaotta F. , Fratianni S. , Cheval S. , Klancar M. , Brunetti M. , Gruber C. , Prohom Duran M. , Likso T. , Esteban P. , Brandsma T.
Published: January 2012

Abstract. The COST (European Cooperation in Science and Technology) Action ES0601: advances in homogenization methods of climate series: an integrated approach (HOME) has executed a blind intercomparison and validation study for monthly homogenization algorithms. Time series of monthly temperature and precipitation were evaluated because of their importance for climate studies and because they represent two important types of statistics (additive and multiplicative). The algorithms were validated against a realistic benchmark dataset. The benchmark contains real inhomogeneous data as well as simulated data with inserted inhomogeneities. Random independent break-type inhomogeneities with normally distributed breakpoint sizes were added to the simulated datasets. To approximate real world conditions, breaks were introduced that occur simultaneously in multiple station series within a simulated network of station data. The simulated time series also contained outliers, missing data periods and local station trends. Further, a stochastic nonlinear global (network-wide) trend was added. Participants provided 25 separate homogenized contributions as part of the blind study. After the deadline at which details of the imposed inhomogeneities were revealed, 22 additional solutions were submitted. These homogenized datasets were assessed by a number of performance metrics including (i) the centered root mean square error relative to the true homogeneous value at various averaging scales, (ii) the error in linear trend estimates and (iii) traditional contingency skill scores. The metrics were computed both using the individual station series as well as the network average regional series. The performance of the contributions depends significantly on the error metric considered. Contingency scores by themselves are not very informative. Although relative homogenization algorithms typically improve the homogeneity of temperature data, only the best ones improve precipitation data. Training the users on homogenization software was found to be very important. Moreover, state-of-the-art relative homogenization algorithms developed to work with an inhomogeneous reference are shown to perform best. The study showed that automatic algorithms can perform as well as manual ones.
Little Ice Age climate and oceanic conditions of the Ross Sea, Antarctica from a coastal ice core record
Authors: Rhodes R. H. , Bertler N. A. N. , Baker J. A. , Steen-Larsen H. C. , Sneed S. B. , Morgenstern U. , Johnsen S. J.
Published: January 2012

Abstract. The Little Ice Age (LIA) is the most recent abrupt climate change event. Understanding its forcings and associated climate system feedbacks is made difficult by a scarcity of Southern Hemisphere paleoclimate records. In this paper we utilise ice core glaciochemical records to reconstruct atmospheric and oceanic conditions in the Ross Sea sector of Antarctic, a region influenced by two contrasting meteorological regimes: katabatic winds and cyclones. Stable isotope (δD) and lithophile element concentration (e.g., Al) records indicate that the region experienced ~1.75 °C cooler temperatures and strong (>57 m s−1) prevailing katabatic winds during the LIA. We observe that the 1590–1875 record is characterised by high d-excess values and marine element (e.g., Na) concentrations, which are linked to the intrusion of cyclonic systems. The strongest katabatic wind events of the LIA, marked by Al, Ti and Pb concentration increases of an order of magnitude (>120 ppb Al), also occur during this interval. Furthermore, concentrations of the biogenic sulphur species MS− suggest that biological productivity in the Ross Sea Polynya was ~80% higher prior to 1875 than in the subsequent time. We propose that colder temperatures and intensified cyclonic activity in the Ross Sea promoted stronger katabatic winds across the Ross Ice Shelf, resulting in an enlarged polynya with increased sea ice and bottom water production. It is therefore hypothesised that increased bottom water formation during the LIA occurred in response to atmospheric circulation change.
Modelling water provision as an ecosystem service in a large East African river basin
Authors: Notter B. , Hurni H. , Wiesmann U. , Abbaspour K. C.
Published: January 2012

Abstract. Reconciling limited water availability with an increasing demand in a sustainable manner requires detailed knowledge on the benefits people obtain from water resources. A frequently advocated approach to deliver such information is the ecosystem services concept. This study quantifies water provision as an ecosystem service for the 43 000 km2 Pangani Basin in Tanzania and Kenya. The starting assumption that an ecosystem service must be valued and accessible by people necessitates the explicit consideration of stakeholders, as well as fine spatial detail in order to determine their access to water. Further requirements include the use of a simulation model to obtain estimates for unmeasured locations and time periods, and uncertainty assessment due to limited data availability and quality. By slightly adapting the hydrological model Soil and Water Assessment Tool (SWAT), developing and applying tools for input pre-processing, and using Sequential Uncertainty Fitting ver. 2 (SUFI-2) in calibration and uncertainty assessment, a watershed model is set up according to these requirements for the Pangani Basin. Indicators for water provision for different uses are derived from model results by combining them with stakeholder requirements and socio-economic datasets such as census or water rights data. Overall water provision is rather low in the basin, however with large spatial variability. On average, for domestic use, livestock, and industry, 86–105 l per capita and day (95% prediction uncertainty, 95 PPU) are available at a reliability level of 95%. 1.19–1.50 ha (95 PPU) of farmland on which a growing period with sufficient water of 3–6 months is reached at the 75% reliability level – suitable for the production of staple crops – are available per farming household, as well as 0.19–0.51 ha (95 PPU) of farmland with a growing period of ≥6 months, suitable for the cultivation of cash crops. The indicators presented reflect stakeholder information needs and can be extracted from the model for any physical or political spatial unit in the basin.
Mapping turbidity layers using seismic oceanography methods
Authors: Vsemirnova E. A. , Hobbs R. W. , Hosegood P.
Published: January 2012

Abstract. Using a combination of seismic oceanographic and physical oceanographic data acquired across the Faroe-Shetland Channel we present evidence of a turbidity layer that transports suspended sediment along the western boundary of the Channel. We focus on reflections observed on seismic data close to the sea-bed on the Faroese side of the Channel below 900 m. Forward modelling based on independent physical oceanographic data show that thermohaline structure does not explain these near sea-bed reflections but they are consistent with optical backscatter data, dry matter concentrations from water samples and from seabed sediment traps. Hence we conclude that an impedance contrast in water column caused by turbidity layers is strong enough to be seen in seismic sections and this provides a new way to visualise this type of current and its lateral structure. By inverting the seismic data we estimate a sediment concentration in the turbidity layers, present at the time of the survey, of 45 ± 25 mg l−1. We believe this is the first direct observation of a turbidity current using Seismic Oceanography.
High frequency fluctuations in the heat content of an ocean general circulation model
Authors: Huerta-Casas A. M. , Webb D. J.
Published: January 2012

Abstract. The transport and storage of heat by the ocean is of crucial importance because of its effect on ocean dynamics and its impact on the atmosphere, climate and climate change. Unfortunately, limits to the amount of data that can be collected and stored means that many experimental and modelling studies of the heat budget have to make use of mean datasets where the effects of short term fluctuations are lost. In this paper we investigate the magnitude of the resulting errors making use of data from OCCAM, a high resolution global ocean model. The model carries out a proper heat balance every timestep so any imbalances that are found in the analysis must result from the use of mean fields. The study concentrates on two areas of the ocean affecting the El Nino. The first is the region of tropical instability waves north of the equator. The second is in the upwelling region along the equator. It is shown that in both cases, processes with a period of less than five days can have a significant impact on the heat budget. Thus analyses using data averaged over five days or more are likely to have significant errors. It is also shown that if a series of instantaneous values is available, reasonable estimates can be made of the size of the errors. In model studies such values are available in the form of the datasets used to restart the model. In experimental studies they may be in the form of individual unaveraged observations.
The impact of a seasonally ice free Arctic Ocean on the temperature, precipitation and surface mass balance of Svalbard
Authors: Day J. J. , Bamber J. L. , Valdes P. J. , Kohler J.
Published: January 2012

Abstract. The observed decline in summer sea ice extent since the 1970s is predicted to continue until the Arctic Ocean is seasonally ice free during the 21st Century. This will lead to a much perturbed Arctic climate with large changes in ocean surface energy flux. Svalbard, located on the present day sea ice edge, contains many low lying ice caps and glaciers and is expected to experience rapid warming over the 21st Century. The total sea level rise if all the land ice on Svalbard were to melt completely is 0.02 m. The purpose of this study is to quantify the impact of climate change on Svalbard's surface mass balance (SMB) and to determine, in particular, what proportion of the projected changes in precipitation and SMB are a result of changes to the Arctic sea ice cover. To investigate this a regional climate model was forced with monthly mean climatologies of sea surface temperature (SST) and sea ice concentration for the periods 1961–1990 and 2061–2090 under two emission scenarios. In a novel forcing experiment, 20th Century SSTs and 21st Century sea ice were used to force one simulation to investigate the role of sea ice forcing. This experiment results in a 3.5 m water equivalent increase in Svalbard's SMB compared to the present day. This is because over 50 % of the projected increase in winter precipitation over Svalbard under the A1B emissions scenario is due to an increase in lower atmosphere moisture content associated with evaporation from the ice free ocean. These results indicate that increases in precipitation due to sea ice decline may act to moderate mass loss from Svalbard's glaciers due to future Arctic warming.
Latin American Cyberculture and Cyberliterature
Authors: Taylor Claire , Pitman Thea
Published: January 2012

This collection of critical essays investigates an emergent and increasingly important field of cultural production in Latin America: cyberliterature and cyberculture in their varying manifestations, including blogs and hypertext narratives, collective novels and e-mags, digital art and short Net-films. Highly innovative in its conception, this book provides the first sustained academic focus on this area of cultural production, and investigates the ways in which cyberliterature and cyberculture in the broadest sense are providing new configurations of subjects, narrative voices, and even political agency, for Latin Americans. The volume is divided into two main sections. The first comprises eight chapters on the broad area of cyberculture and identity formation/preservation including the development of different types of cybercommunities in Latin America. While many of the chapters applaud the creative potential of these new virtual communities, identities and cultural products to create networks across boundaries and offer new contestatory strategies, they also consider whether such phenomena may risk reinforcing existing social inequalities or perpetuate conservatism. The second section comprises six chapters and an afterword that deal with the nature of cyberliterature in all its many forms, from the (cyber)cultural legacies of writers such as Julio Cortázar and Jorge Luis Borges, to traditional print literature from the region that reflects on the subject of new technology, to weblogs and hypertext and hypermedia fiction proper.
Randomized clinical trial of external stent drainage of the pancreatic duct to reduce postoperative pancreatic fistula after pancreaticojejunostomy
Authors: Motoi F , Egawa S , Rikiyama T , Katayose Y , Unno M
Published: January 2012

Background

Postoperative pancreatic fistula (POPF) remains one of the most common causes of morbidity following pancreaticoduodenectomy (PD). This randomized trial examined whether external stent drainage of the pancreatic duct decreases the rate of POPF after PD and subsequent pancreaticojejunostomy (PJ).

Methods

Consecutive patients who underwent PD with subsequent construction of a duct-to-mucosa PJ were randomized into a stented and a non-stented group. The primary outcome was the incidence of clinically relevant POPF. Secondary outcomes were morbidity and mortality rates, and hospital stay.

Results

Of 114 PD procedures, 93 were suitable for inclusion in the study after informed consent. The rate of clinically relevant POPF was significantly lower in the stented group than in the non-stented group: three of 47 (6 per cent) versus ten of 46 (22 per cent) (P = 0·040). Among patients with a dilated duct, rates of POPF were similar in both groups. Among patients with a non-dilated duct, clinically relevant POPF was significantly less common in the stented group than in the non-stented group: two of 21 (10 per cent) versus eight of 20 (40 per cent) (P = 0·033). No significant differences in morbidity or mortality were observed. Univariable analysis identified body mass index (BMI), pancreatic cancer, pancreatic texture, pancreatic duct size and duct stenting as risk factors related to clinically relevant POPF. Multivariable analysis taking these five factors into account identified high BMI (risk ratio (RR) 11·45; P = 0·008), non-dilated duct (RR 5·33; P = 0·046) and no stent (RR 10·38; P = 0·004) as significant risk factors.

Conclusion

External duct stenting reduced the risk of clinically relevant POPF after PD and subsequent duct-to-mucosa PJ. Registration number: UMIN000000952 (http://www.umin.ac.jp/ctr/index-j.htm).
Transcatheter closure of atrial septal defect in a geriatric population
Authors: Nakagawa Koji , Akagi Teiji , Taniguchi Manabu , Kijima Yasufumi , Goto Keiji , Kusano Kengo F. , Itoh Hiroshi , Sano Shunji
Published: January 2012

Objectives: To evaluate the efficacy and safety of transcatheter closure of atrial septal defects (ASD) in patients over 70 years of age. Background: Transcatheter closure of ASD is an established procedure in children and young adults, but the benefits of this procedure in geriatric patients are still unclear. Methods: Between 2005 and 2010, 430 patients with ASD underwent transcatheter closure in our hospital. Among those patients, 30 consecutive patients older than 70 years of age were prospectively evaluated. Results: Mean age at procedure was 75.8 ± 3.8 years (range: 70–85 years). Mean Qp/Qs was 2.4 ± 0.7 and mean ASD diameter was 20.3 ± 6.4 mm. Nine patients (30%) had a history of hospitalization due to heart failure. ASD closure was successfully performed in 28 patients (93%) without significant complications. During the follow‐up period (mean period of 19.1 ± 11.3 months), New York Heart Association (NYHA) functional class was significantly improved in 20 patients (74%). Significant improvements of plasma BNP level, resting heart rate, and systolic pulmonary artery pressure were also observed. Improvement of tricuspid regurgitation was observed in 11 of 17 patients with moderate or severe regurgitation during the follow‐up period. Conversely, worsening of mitral regurgitation was observed in 10 of the 27 patients. Conclusion: Transcatheter closure of ASD in geriatric patients can be performed safely. This procedure contributes to significant improvement of symptoms and positive cardiac remodeling. Long‐term follow‐up is mandatory, especially for patients with mitral regurgitation. © 2012 Wiley Periodicals, Inc.
Purification process of phosphoric acid by vertical zone‐melting technique
Authors: Ren Yong‐sheng , Duan Xiao‐xiao
Published: January 2012

The efficiency of vertical zone‐melting technique as a function of molten‐zone length, number of zone passes, molten‐zone velocity and phosphoric acid concentration on the purification process of phosphoric acid is studied. The results showed that adopting a relatively long molten‐zone length in the initial passes to effect a rapid movement of impurities and a short molten‐zone length in the later passes to obtain greater purification; additional zone‐passes cannot be made as impurities redistribution approaches limiting distribution; for stirring mechanism is not adopted in the present study and as diffusion is the only mixing process, slow molten‐zone velocity 3–6 mm h−1 is better; the purification efficiency increases with phosphoric acid concentration, and 94–99.8% concentration of phosphoric acid is better. © 2012 Canadian Society for Chemical Engineering
CFD simulation for biomagnetic separation involving dilute suspensions
Authors: Khashan Saud A. , Haik Yousef , Elnajjar Emad
Published: January 2012

Full‐Eulerian simulation of the separation of magnetic particles carried by a Newtonian fluid through a planar channel under the influence of a magnetic field is presented. The simulation is based on the application of the Navier–Stokes and concentration equations. The scheme for the magnetic separation of particles is achieved by applying an external magnetic dipole field. The hydrodynamic and magnetophoretic interactions between the particles and the carrier fluid are analysed. Analysis of the competing tendencies of mass transfer indicates that the magnetophoresis migration of magnetic particles is dominant over the molecular diffusion. This dominance becomes more evident at lower diffusivities leading to a drastic magnetic separation confined within a small region in the proximity of the magnetic field source. © 2012 Canadian Society for Chemical Engineering
Commentary on ‘Mass media interventions for preventing smoking in young people’
Authors: Prokhorov Alexander V. , Calabro Karen S.
Published: January 2012

This is a commentary of Cochrane review, published in this issue of EBCH, first published as: Brinn MP, Carson KV, Esterman AJ, Chang AB, Smith BJ. Mass media interventions for preventing smoking in young people. Cochrane Database of Systematic Reviews 2010, Issue 11. Art. No.: CD001006. DOI: 10.1002/14651858.CD001006.pub2.

Further information for this Cochrane review is available in this issue of EBCH in the accompanying Summary article. Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. The Cochrane Collaboration
New Anthracene Derivatives – Structure Elucidation and Antimicrobial Activity
Authors: Debbab Abdessamad , Aly Amal H. , Edrada‐Ebel Ruangelie , Wray Victor , Pretsch Alexander , Pescitelli Gennaro , Kurtan Tibor , Proksch Peter
Published: January 2012

Three new anthracene derivatives, which include tetrahydroanthraquinone 1 and two tetrahydroanthraquinone heterodimers 2 and 3, were isolated from Stemphylium globuliferum, together with four known metabolites 4–7. Detailed analysis of the spectroscopic data allowed the unambiguous determination of the structures of 1 and 2 and a revision of the structure of alterporriol C and its atropisomer. Furthermore, alterporriol G, previously obtained as part of a mixture, was isolated in its pure form for the first time and its structure was also revised. The absolute configurations of 1, 2 and 3 were assigned by calculation of their CD spectra, which also allowed the configurational assignment of altersolanol A and the determination of the axial chirality of alterporriols D and E. All isolated compounds were analysed for their antimicrobial and cytotoxic activities. Compounds 1 and 5 inhibited the growth of most pathogenic microorganisms tested, whereas 2, 6 and 7 showed selective inhibition of bacteria but were inactive against fungi.
Serotonin 6 receptor gene and schizophrenia: case‐control study and meta‐analysis
Authors: Kishi Taro , Fukuo Yasuhisa , Okochi Tomo , Kawashima Kunihiro , Kitajima Tsuyoshi , Inada Toshiya , Ozaki Norio , Musso Giovanna M. , Kane John M. , Correll Christoph U. , Iwata Nakao
Published: January 2012

Objectives

Several lines of evidence suggest that genetic alterations in serotonin 6 (5‐HT6) receptors might be associated with the pathophysiology of schizophrenia. We sought to assess the relationship between genotype alterations in 5‐HT6 receptors and schizophrenia both in a case‐control study and a meta‐analysis.

Methods

We conducted an association study of the 5‐HT6 receptor gene (HTR6) in Japanese patients with schizophrenia (n = 836) and controls (n = 857). Five tagging single‐nucleotide polymorphisms (SNPs), including rs1805054 (C267T) in HTR6, were selected. In addition, we carried out a meta‐analysis between rs1805054, which has been examined in other studies, and schizophrenia, searching PubMed through August 2011.

Results

There were no significant associations between the tagging SNPs in HTR6 and schizophrenia in any of the genotype models in both the simple and the multiple logistic regression analyses correcting for potential confounds. Similarly, no significant association was found in the all‐marker haplotype multiple logistic regression analysis (p = 0.491).

Moreover, in the meta‐analysis of rs1805054, drawing data from five studies, including our own (schizophrenia patients = 1366, controls = 1376), rs1805054 was also not associated with schizophrenia.

Conclusions

Our results indicate that tagging SNPs in HTR6 may not play a role in the pathophysiology of schizophrenia. Copyright © 2012 John Wiley & Sons, Ltd.
Dual wavelength tumor targeting for detection of hypopharyngeal cancer using near‐infrared optical imaging in an animal model
Authors: Keereweer Stijn , Mol Isabel M. , Vahrmeijer Alexander L. , Van Driel Pieter B.A.A. , Baatenburg de Jong Robert J. , Kerrebijn Jeroen D.F. , Löwik Clemens W.G.M.
Published: January 2012

Optical imaging is a promising technique to visualize cancer tissue during surgery. In this study, we explored the use of combinations of near‐infrared (NIR) fluorescence agents that emit fluorescence signal at different wavelengths and each target specific tumor characteristics. Two combinations of agents (ProSense680 combined with 2DG CW800 and MMPSense680 combined with EGF CW800) were used to detect hypopharyngeal cancer in an animal model. ProSense680 and MMPSense680 detect increased activity of cathepsins and matrix metalloproteinases, respectively. These enzymes are mainly found in the invasive tumor border due to degradation of the extracellular matrix. 2DG CW800 detects tumor cells with high glucose metabolism and EGF CW800 is internalized by the epidermal growth factor receptor of tumor cells. Whole‐body imaging revealed clear demarcation of tumor tissue using all four agents. The tumor‐to‐background ratio (standard deviation, p‐value) was 3.69 (0.72, p < 0.001) for ProSense680; 4.26 (1.33, p < 0.001) for MMPSense680; 5.81 (3.59, p = 0.02) for 2DG CW800 and 4.84 (1.56, p < 0.001) for EGF CW800. Fluorescence signal corresponded with histopathology and immunohistochemistry, demonstrating signal of ProSense680 and MMPSense680 in the invasive tumor border, and signal of 2DG CW800 and EGF CW800 in the tumor tissue. In conclusion, we demonstrated the feasibility of dual wavelength tumor detection using different targeting strategies simultaneously in an animal model. Combined targeting at different wavelengths allowed simultaneous imaging of different tumor characteristics. NIR fluorescence optical imaging has the potential to be translated into the clinic in order to improve the complete removal of tumors by real‐time image‐guided surgery.
Age‐dependent accumulation of genomic aberrations and deregulation of cell cycle and telomerase genes in metastatic neuroblastoma
Authors: Coco Simona , Theissen Jessica , Scaruffi Paola , Stigliani Sara , Moretti Stefano , Oberthuer André , Valdora Francesca , Fischer Matthias , Gallo Fabio , Hero Barbara , Bonassi Stefano , Berthold Frank , Tonini Gian Paolo
Published: January 2012

About 50% of children with neuroblastoma (NB) show a metastatic disease and have a poor prognosis. However, disease progression is greatly variable and depends on patients' age and MYCN oncogene amplification. To investigate the role of patients' age in tumor aggressiveness, we performed array‐CGH and gene expression profiles of three groups (G) of metastatic NBs: G1, stage 4S patients and MYCN single copy (MYCN−) tumors; G2, stage 4 patients, ≤18 months of age, MYCN− tumors and favorable outcome and G3, Stage 4 patients, ≥19 months with unfavorable outcome. G1 was characterized by numerical aberrations prevalently; on the contrary, all G3 tumors had structural rearrangements, whereas G2 showed an intermediate pattern. The average of numerical alterations decreased significantly from G1 to G2 to G3 (p < 0.01). Contrarily, the number of structural aberrations increased from G1 to G2 to G3 (p < 2.35 E−05). Noteworthy, G3/MYCN− NBs were characterized by several complex intrachromosome rearrangements. Expression analysis of the three groups showed significant differences in genes of Rho and Ras signaling pathways, development and adhesion, cell cycle regulation and telomerase activity. Accumulation of structural alterations increased with patients' age and was associated with a more aggressive disease. Abnormal expression of genes involved in cell cycle and telomerase in G3 may be responsible for the genomic instability in this cohort of patients. The higher DNA instability observed in G3/MYCN− NBs than in MYCN‐amplified G3 may also explain why patients ≥19 months have a poor outcome independently by MYCN status.