bluuebunny/crossref_metadata_2025 huggingface dataset:
Metallic Contaminant Detection System Using Multi-Channel Superconducting Quantum Interference Device (SQUID)
Authors: Tanaka Saburo , Ohtani Takeyoshi , Uchida Yosuke , Chigasaki Takumi , Hatsukade Yoshimi
Published: April 2014

Metallic particles with outer dimensions smaller than 100 microns in Li-ion battery cannot be detected using a conventional X-ray imaging system. We propose two systems using high Tc SQUIDs: One is a direct detection type and the other is an indirect type. In the direct detection system, an object with a contaminant is magnetized by a permanent magnet and then the remanent field of the contaminant is detected by SQUID. In the indirect detection system, the principle is based on Faradays law of electromagnetic induction. The diameter of the detection coil is 2 to 3 times larger than the SQUID; as a result, less number of SQUIDs, two or three is enough to inspect a specimen with a width of 65 mm. This method is applicable for an inspection of metallic contaminants in non-magnetic film such as a separator for Li-ion battery. We discuss the results of the evaluation of the new system as compared with a direct detection system.
Sharp Angular Dependence of Free Layer Coercivity in Spin Valves with Ferromagnetic Interlayer Coupling
Authors: Naumova Larisa I. , Milyaev M.A. , Bebenin N.G. , Chernyshova Tatyana A. , Proglyado Vyacheslav V. , Krinitsina Tatiana P. , Bannikova Nataly S. , Kamensky Ivan Yu. , Ustinov V.V.
Published: April 2014

The dependence of free layer coercivity on the angle between easy axis and applied magnetic field was studied on [Ta, (Ni80Fe20)60Cr40]/ Ni80Fe20/Co90Fe10/Cu/Co90Fe10/Mn75Ir25/Ta spin valves with various interlayer coupling. Sharp decrease on the angle was observed for ferromagnetically coupled spin valves. The coercivity was reduced down to tenth of Oersted without any decrease of GMR-effect by forming nearly parallel anisotropy configuration. The angles at which the transition from hysteretic to anhysteretic magnetic reversal takes place are detected by analyses of the angle dependence of coercivity. Interpretation of experimental data is based on Stoner-Wohlfarth coherent rotation approach.
Synthesis and Study of the New Class of Magnetic Bioceramics for Biomedical Applications: Mossbauer Studies
Authors: Tkachenko M.V. , Kamzin A.S. , Ol’khovik L.P. , Тkachenko T.M. , Keshri S.
Published: April 2014

Magnetic bioceramics based on hydroxyapatite Ca5(PO4)3OH and particles of the M-type hexagonal (barium or calcium) ferrite (taken in proportions 5, 10, 20, 25, 40 and 50 wt % of M-ferrite) with a high bioactivity and magnetic characteristics providing hyperthermal treatment of oncology diseases has been developed and studied. The phase composition, microstructure, and magnetic properties of the synthesized bioceramics have been determined by using electron diffraction patterns, electron microscope micrograms and Mossbauer spectroscopy. It has been shown that the synthesized biomaterial consists of the biocompatible matrix with the apatite structure into which particles of hexagonal ferrite are incorporated. The Mossbauer spectra for all the samples clearly indicates that the particles of hexagonal ferrite are in the ferromagnetic state and small part of particles in paramagnetic state. The magnetic parameters of the synthesized ceramics are substantially higher than those of the bioglass ceramics modified by iron oxides that have been used in medicine, which suggests good potential and effectiveness of application of the created ceramics for medical purposes. Thus, a new class of magnetic bioceramics combining hydroxyapatite Ca5(PO4)3OH, which exhibits good properties in biocompatibility and bioactivity, with particles of the M-type hexagonal ferrite, which possess high magnetic characteristics, has been created.
Partially Disordered State in the Frustrated Heisenberg Ferrimagnet
Authors: Martynov Sergey N.
Published: April 2014

A model for the description of two-subsystem Heisenberg ferrimagnet with frustrated intersubsystem exchange and competition between exchange interactions in a subsystem is proposed. The conditions of the existence of noncollinear Yafet-Kittel state and partially ordered magnetic structure are investigated. The phase diagram of competition parameter vs temperature is obtained in the mean field approximation. The peculiarities of the succesive magnetic phase transitions are considered.
Peculiarities of the Magnetocaloric Effect in an Isotropic Antiferromagnet
Authors: Kassan-Ogly Felix A. , Kokorina Elena E. , Medvedev M.V.
Published: April 2014

It is shown that the magnetocaloric effects are absent in the spin-flop phase of an isotropic antiferromagnet at the T<TN (TN the Neel temperature) and appear only when an applied magnetic field exceeds the critical field of the spin-flip transition. It is displayed as well that the direct magnetocaloric effects in an antiferromagnet above TN are much less that the analogous effects in a ferromagnet above the Curie point TC.
Effect of Cobalt Deficiency on Physical Properties of the GdBaCo2-xO5+δ Single Crystal
Authors: Arbuzova Tamara I. , Telegin Sergey V. , Naumov Sergey V. , Patrakov Eugeniy I. , Reznitskih Olga G.
Published: April 2014

The effect of cobalt deficiency in a single crystal of double layered cobaltite GdBaCo1.86O5.32 on the magnetic properties was investigated. We have found that in the region 210 - 400 K the sample has the ferrimagnetic state with the Neel temperature (TN ~ 400 K) which is above the Curie temperature (TC ~ 262 K). In the paramagnetic region T = 410 - 650 K the effective magnetic moment is μeff = 8.78 μB, that points out the intermediate spin state (IS) of Co3+ ions.
Quantum Theory of Magnetoelectric Properties of Rare-Earth Alumoborates: Holmium Alumoborate
Authors: Kostyuchenko Nadezhda V. , Popov Alexander I. , Zvezdin Anatoly K.
Published: April 2014

The magnetization processes of HoAl3(BO3)4rare-earth aluminum borates have been studied theoretically. Magnetic properties of the crystals were examined. The dependencies of the magnetic susceptibility on the magnitude and direction of magnetic field were calculated. Study of a magnetoelectric effect was performed and the dependencies of the polarization on the strength and orientation of a magnetic field and temperature were obtained. A comparison of the theoretical and experimental data was performed, their consistency has been ascertained.
The Nuclear Receptor Nr4a1 Mediates Anti-Inflammatory Effects of Apoptotic Cells
Authors: Ipseiz Natacha , Uderhardt Stefan , Scholtysek Carina , Steffen Martin , Schabbauer Gernot , Bozec Aline , Schett Georg , Krönke Gerhard
Published: April 2014

Uptake of apoptotic cells (ACs) by macrophages ensures the nonimmunogenic clearance of dying cells, as well as the maintenance of self-tolerance to AC-derived autoantigens. Upon ingestion, ACs exert an inhibitory influence on the inflammatory signaling within the phagocyte. However, the molecular signals that mediate these immune-modulatory properties of ACs are incompletely understood. In this article, we show that the phagocytosis of apoptotic thymocytes was enhanced in tissue-resident macrophages where this process resulted in the inhibition of NF-κB signaling and repression of inflammatory cytokines, such as IL-12. In parallel, ACs induced a robust expression of a panel of immediate early genes, which included the Nr4a subfamily of nuclear receptors. Notably, deletion of Nr4a1 interfered with the anti-inflammatory effects of ACs in macrophages and restored both NF-κB signaling and IL-12 expression. Accordingly, Nr4a1 mediated the anti-inflammatory properties of ACs in vivo and was required for maintenance of self-tolerance in the murine model of pristane-induced lupus. Thus, our data point toward a key role for Nr4a1 as regulator of the immune response to ACs and of the maintenance of tolerance to “dying self.”
Existence of Conventional Dendritic Cells in Gallus gallus Revealed by Comparative Gene Expression Profiling
Authors: Vu Manh Thien-Phong , Marty Hélène , Sibille Pierre , Le Vern Yves , Kaspers Bernd , Dalod Marc , Schwartz-Cornil Isabelle , Quéré Pascale
Published: April 2014

The existence of conventional dendritic cells (cDCs) has not yet been demonstrated outside mammals. In this article, we identified bona fide cDCs in chicken spleen. Comparative profiling of global and of immune response gene expression, morphology, and T cell activation properties show that cDCs and macrophages (MPs) exist as distinct mononuclear phagocytes in the chicken, resembling their human and mouse cell counterparts. With computational analysis, core gene expression signatures for cDCs, MPs, and T and B cells across the chicken, human, and mouse were established, which will facilitate the identification of these subsets in other vertebrates. Overall, this study, by extending the newly uncovered cDC and MP paradigm to the chicken, suggests that these two phagocyte lineages were already in place in the common ancestor of reptiles (including birds) and mammals in evolution. It opens avenues for the design of new vaccines and nutraceuticals that are mandatory for the sustained supply of poultry products in the expanding human population.
Facies relationships at the Mississippian carbonate platform margin, western Canada
Authors: Bamber E W , Richards B C , Macqueen R W
Published: April 2014

In the Eastern Cordillera and western Plains of Canada, the Mississippian succession consists of an eastern belt of thick, platform carbonates and detrital clastics that grade laterally into a western belt of this, basinal shale across a transitional platform
margin with a very low depositional slope. This facies change is accompanied by marked stratigraphic condensation. The eastern facies belt consists almost entirely of carbonates in the southern Canadian Rockies. There, neither the shale belt bor the westernmost part of the carbonate-clastic belt is
preserved. Within the preserved part of the carbonate-clastic belt, near-shore to open marine facies migrated toward the west through time, producing a shallowing-upward succession indicating major regression. Terrigenous clastics became widespread in latest Mississippian time. In northeastern
British Columbia, southwestern District of Mackkenzie, and southeastern Yukon Territory, facies distribution within the carbonate-clastic belt is similar to that in the south, but terrigenous clastics became dominant by early Late Viséan time. The westward transition to shale, exposed in this
area, begins with the oldest carbonate units in the east and progresses upward through the succession, such that the youngest carbonate and clastic units extend farthest west into the shale basin. In southwestern District of Mackenzie, turbidite features, such as graded bedding and channel fillings,
occur in carbonates adjacent to the eastern edge of the shale belt. In the nothern Yukon Territory, Upper Mississippian near-shore clastic deposits and shallow-marine carbonate facies show a preogressive northeastward migration toward the craton, in contrast to the baseward progression farther
south. The deepening-upward succession of the northern Yukon Territory indicates marine transgression during Late Mississippian time (Middle Viséan to Early Namurian) with deposition of thinner slope sediments and basinal shale to the southwest.
Prayer Book Catechism: Past its sell-by date?
Authors: Potgieter Raymond
Published: April 2014

The Book of Common Prayer (BCP) is the first introduction to Anglican belief and liturgy for many. More specifically, the Book of Common Prayer of 1662 contains the traditional catechism of the Church of England, enjoining catechumens to receive training and instruction in basic doctrines and Christian living. This takes place in the contexts of the liturgy and the more comprehensive doctrinal statements of the 39 Articles of Religion. Anglican religion traditionally allowed its members to verbalise their faith in both ritual and confession, thus serving the church and not so much life in the world. A revisit of the intentions of the catechism within its historical and prayer book contexts will show that it essentially expresses lasting truths of the Christian faith. In a world increasingly divorced from particular Christian expressions, the Anglican Church needs to rethink its particular use of the catechism for its continued relevance in meeting the questions and challenges Anglicans face daily.
Characterization of uncertainties in atmospheric trace gas inversions using hierarchical Bayesian methods
Authors: Ganesan A. L. , Rigby M. , Zammit-Mangion A. , Manning A. J. , Prinn R. G. , Fraser P. J. , Harth C. M. , Kim K.-R. , Krummel P. B. , Li S. , Mühle J. , O'Doherty S. J. , Park S. , Salameh P. K. , Steele L. P. , Weiss R. F.
Published: April 2014

Abstract. We present a hierarchical Bayesian method for atmospheric trace gas inversions. This method is used to estimate emissions of trace gases as well as "hyper-parameters" that characterize the probability density functions (PDFs) of the a priori emissions and model-measurement covariances. By exploring the space of "uncertainties in uncertainties", we show that the hierarchical method results in a more complete estimation of emissions and their uncertainties than traditional Bayesian inversions, which rely heavily on expert judgment. We present an analysis that shows the effect of including hyper-parameters, which are themselves informed by the data, and show that this method can serve to reduce the effect of errors in assumptions made about the a priori emissions and model-measurement uncertainties. We then apply this method to the estimation of sulfur hexafluoride (SF6) emissions over 2012 for the regions surrounding four Advanced Global Atmospheric Gases Experiment (AGAGE) stations. We find that improper accounting of model representation uncertainties, in particular, can lead to the derivation of emissions and associated uncertainties that are unrealistic and show that those derived using the hierarchical method are likely to be more representative of the true uncertainties in the system. We demonstrate through this SF6 case study that this method is less sensitive to outliers in the data and to subjective assumptions about a priori emissions and model-measurement uncertainties than traditional methods.
Climatology of new particle formation at Izaña mountain GAW observatory in the subtropical North Atlantic
Authors: García M. I. , Rodríguez S. , González Y. , García R. D.
Published: April 2014

Abstract. A climatology of new particle formation (NPF) events at high altitude in the subtropical North Atlantic is presented. A 4-year data set (June 2008–June 2012), which includes number size distributions (10–600 nm), reactive gases (SO2, NOx, and O3), several components of solar radiation and meteorological parameters, measured at Izaña Global Atmosphere Watch (GAW) observatory (2373 m above sea level; Tenerife, Canary Islands) was analysed. NPF is associated with the transport of gaseous precursors from the boundary layer by orographic buoyant upward flows that perturb the low free troposphere during daytime. On average, 30% of the days contained an NPF event. Mean values of the formation and growth rates during the study period were 0.46 cm−3 s−1 and 0.42 nm h−1, correspondingly. There is a clearly marked NPF season (May–August), when these events account for 50–60% of the days per month. Monthly mean values of the formation and growth rates exhibit higher values in this season, 0.49–0.92 cm−3 s−1 and 0.48–0.58 nm h−1, respectively. During NPF events, SO2, UV radiation and upslope winds showed higher values than during non-events. The overall data set indicates that SO2 plays a key role as precursor, although other species seem to contribute during some periods. Condensation of sulfuric acid vapour accounts for most of the measured particle growth during most of the year (~70%), except for some periods. In May, the highest mean growth rates (~0.6 nm h−1) and the lowest contribution of sulfuric acid (~13%) were measured, suggesting a significant involvement of other condensing vapours. The SO2 availability seems also to be the most influencing parameter in the year-to-year variability in the frequency of NPF events. The condensation sink showed similar features to other mountain sites, showing high values during NPF events. Summertime observations, when Izaña is within the Saharan Air Layer, suggest that dust particles may play a significant role acting as coagulation sink of freshly formed nucleation particles. The contribution of dust particles to the condensation sink of sulfuric acid vapours seems to be modest (~8% as average). Finally, we identified a set of NPF events in which two nucleation modes, which may evolve at different rates, occur simultaneously and for which further investigations are necessary.
Surface response to rain events throughout the West African monsoon
Authors: Lohou F. , Kergoat L. , Guichard F. , Boone A. , Cappelaere B. , Cohard J.-M. , Demarty J. , Galle S. , Grippa M. , Peugeot C. , Ramier D. , Taylor C. M. , Timouk F.
Published: April 2014

Abstract. This study analyses the response of the continental surface to rain events, taking advantage of the long-term near-surface measurements over different vegetation types at different latitudes, acquired during the African Monsoon Multidisciplinary Analysis (AMMA) by the AMMA-CATCH observing system. The simulated surface response by nine land surface models involved in AMMA Land Model Intercomparison Project (ALMIP), is compared to the observations. The surface response, described via the evaporative fraction (EF), evolves in two steps: the immediate surface response (corresponding to an increase of EF occurring immediately after the rain) and the surface recovery (characterized by a decrease of EF over several days after the rain). It is shown that, for all the experimental sites, the immediate surface response is mainly dependent on the soil moisture content and the recovery period follows an exponential relationship whose rate is strongly dependent on the vegetation type (from 1 day over bare soil to 70 days over forest) and plant functional type (below and above 10 days for annual and perennial plants, respectively). The ALMIP model ensemble depicts a broad range of relationships between EF and soil moisture, with the worst results for the drier sites (high latitudes). The land surface models tend to simulate a realistic surface recovery for vegetated sites, but a slower and more variable EF decrease is simulated over bare soil than observed.
Representing ozone extremes in European megacities: the importance of resolution in a global chemistry climate model
Authors: Stock Z. S. , Russo M. R. , Pyle J. A.
Published: April 2014

Abstract. The continuing growth of the world's urban population has led to an increasing number of cities with more than 10 million inhabitants. The higher emissions of pollutants, coupled to higher population density, makes predictions of air quality in these megacities of particular importance from both a science and a policy perspective. Global climate models are typically run at coarse resolution to enable both the efficient running of long time integrations, and the ability to run multiple future climate scenarios. However, when considering surface ozone concentrations at the local scale, coarse resolution can lead to inaccuracies arising from the highly nonlinear ozone chemistry and the sensitivity of ozone to the distribution of its precursors on smaller scales. In this study, we use UM-UKCA, a global atmospheric chemistry model, coupled to the UK Met Office Unified Model, to investigate the impact of model resolution on tropospheric ozone, ranging from global to local scales. We focus on the model's ability to represent the probability of high ozone concentrations in the summer and low ozone concentrations, associated with polluted megacity environments, in the winter, and how this varies with horizontal resolution. We perform time-slice integrations with two model configurations at typical climate resolution (CR, ~150 km) and at a higher resolution (HR, ~40 km). The CR configuration leads to overestimation of ozone concentrations on both regional and local scales, while it gives broadly similar results to the HR configuration on the global scale. The HR configuration is found to produce a more realistic diurnal cycle of ozone concentrations and to give a better representation of the probability density function of ozone values in urban areas such as the megacities of London and Paris. We find the observed differences in model behaviour between CR and HR configurations to be largely caused by chemical differences during the winter and meteorological differences during the summer.
On the abundance and source contributions of dicarboxylic acids in size-resolved aerosol particles at continental sites in central Europe
Authors: van Pinxteren D. , Neusüß C. , Herrmann H.
Published: April 2014

Abstract. Dicarboxylic acids (DCAs) are among the most abundant organic compounds observed in atmospheric aerosol particles and have been extensively studied at many places around the world. The importance of the various primary sources and secondary formation pathways discussed in the literature is often difficult to assess from field studies, though. In the present study, a large data set of size-resolved DCA concentrations from several inland sites in Germany is combined with results from a recently developed approach of statistical back-trajectory analysis and additional data. Principal component analysis is then used to reveal the most important factors governing the abundance of DCAs in different particle size ranges. The two most important sources revealed are (i) photochemical formation during intense radiation days in polluted air masses, likely occurring in the gas phase on short timescales (gasSOA), and (ii) secondary reactions in anthropogenically influenced air masses, likely occurring in the aqueous phase on longer timescales (aqSOA). While the first source strongly impacts DCA concentrations mainly in small and large particles, the second one enhances accumulation mode DCAs and is responsible for the bulk of the observed concentrations. Primary sources were found to be minor (sea salt, soil resuspension) or non-existent (biomass burning, traffic). The results can be regarded as representative for typical central European continental conditions.
Satellite observations indicate substantial spatiotemporal variability in biomass burning NOx emission factors for South America
Authors: Castellanos P. , Boersma K. F. , van der Werf G. R.
Published: April 2014

Abstract. Biomass burning is an important contributor to global total emissions of NOx (NO+NO2). Generally bottom-up fire emissions models calculate NOx emissions by multiplying fuel consumption estimates with static biome-specific emission factors, defined in units of grams of NO per kilogram of dry matter consumed. Emission factors are a significant source of uncertainty in bottom-up fire emissions modeling because relatively few observations are available to characterize the large spatial and temporal variability of burning conditions. In this paper we use NO2 tropospheric column observations from the Ozone Monitoring Instrument (OMI) from the year 2005 over South America to calculate monthly NOx emission factors for four fire types: deforestation, savanna/grassland, woodland, and agricultural waste burning. In general, the spatial patterns in NOx emission factors calculated in this work are consistent with emission factors derived from in situ measurements from the region but are more variable than published biome-specific global average emission factors widely used in bottom-up fire emissions inventories such as the Global Fire Emissions Database (GFED). Satellite-based NOx emission factors also indicate substantial temporal variability in burning conditions. Overall, we found that deforestation fires have the lowest NOx emission factors, on average 30% lower than the emission factors used in GFED v3. Agricultural fire NOx emission factors were the highest, on average a factor of 1.8 higher than GFED v3 values. For savanna, woodland, and deforestation fires, early dry season NOx emission factors were a factor of ~1.5–2 higher than late dry season emission factors. A minimum in the NOx emission factor seasonal cycle for deforestation fires occurred in August, the time period of severe drought in South America in 2005, supporting the hypothesis that prolonged dry spells may lead to an increase in the contribution of smoldering combustion from large-diameter fuels, offsetting the higher combustion efficiency of dryer fine fuels. We evaluated the OMI-derived NOx emission factors with SCIAMACHY NO2 tropospheric column observations and found improved model performance in regions dominated by fire emissions.
Long-term changes in the upper stratospheric ozone at Syowa, Antarctica
Authors: Miyagawa K. , Petropavlovskikh I. , Evans R. D. , Long C. , Wild J. , Manney G. L. , Daffer W. H.
Published: April 2014

Abstract. Analyses of stratospheric ozone data determined from Dobson–Umkehr measurements since 1977 at the Syowa (69.0° S, 39.6° E), Antarctica, station show a significant decrease in ozone at altitudes higher than that of the 4 hPa pressure level during the 1980s and 1990s. Ozone values over Syowa have remained low since 2001. The time series of upper stratospheric ozone from the homogenized NOAA SBUV (Solar Backscatter Ultraviolet Instrument)(/2) 8.6 overpass data (±4°, 24 h) are in qualitative agreement with those from the Syowa station data. Ozone recovery during the austral spring over the Syowa station appears to be slower than predicted by the equivalent effective stratospheric chlorine (EESC) curve. The long-term changes in the station's equivalent latitude (indicative of vortex size/position in winter and spring) are derived from MERRA (Modern Era Retrospective-analysis for Research and Applications) reanalyses at ~ 2 and ~ 50 hPa. These data are used to attribute some of the upper and middle stratospheric ozone changes to the changes in vortex position relative to the station's location. In addition, high correlation of the Southern Hemisphere annular mode (SAM) with polar upper stratospheric ozone during years of maximum solar activity points toward a strong relationship between the strength of the Brewer–Dobson circulation and the polar stratospheric ozone recovery. In the lower stratosphere, ozone recovery attributable to CFCs (chlorofluorocarbons) is still not definitive, whereas the recovery of the upper stratosphere is slower than predicted. Further research indicates that dynamical and other chemical changes in the atmosphere are delaying detection of recovery over this station.
Trace gas emissions from combustion of peat, crop residue, biofuels, grasses, and other fuels: configuration and FTIR component of the fourth Fire Lab at Missoula Experiment (FLAME-4)
Authors: Stockwell C. E. , Yokelson R. J. , Kreidenweis S. M. , Robinson A. L. , DeMott P. J. , Sullivan R. C. , Reardon J. , Ryan K. C. , Griffith D. W. T. , Stevens L.
Published: April 2014

Abstract. During the fourth Fire Lab at Missoula Experiment (FLAME-4, October–November~2012) a~large variety of regionally and globally significant biomass fuels was burned at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particle emissions were characterized by an extensive suite of instrumentation that measured aerosol chemistry, size distribution, optical properties, and cloud-nucleating properties. The trace gas measurements included high resolution mass spectrometry, one- and two-dimensional gas chromatography, and open-path Fourier transform infrared (OP-FTIR) spectroscopy. This paper summarizes the overall experimental design for FLAME-4 including the fuel properties, the nature of the burn simulations, the instrumentation employed, and then focuses on the OP-FTIR results. The OP-FTIR was used to measure the initial emissions of 20 trace gases: CO2, CO, CH4, C2H2, C2H4, C3H6, HCHO, HCOOH, CH3OH, CH3COOH, glycolaldehyde, furan, H2O, NO, NO2, HONO, NH3, HCN, HCl, and SO2. These species include most of the major trace gases emitted by biomass burning and for several of these compounds it is the first time their emissions are reported for important fuel types. The main fuel types included: African grasses, Asian rice straw, cooking fires (open (3-stone), rocket, and gasifier stoves), Indonesian and extratropical peat, temperate and boreal coniferous canopy fuels, US crop residue, shredded tires, and trash. Comparisons of the OP-FTIR emission factors (EF) and emission ratios (ER) to field measurements of biomass burning verify that the large body of FLAME-4 results can be used to enhance the understanding of global biomass burning and its representation in atmospheric chemistry models.
Variability of tropospheric methane above the Mediterranean Basin inferred from satellite and model data
Authors: Ricaud P. , Sič B. , El Amraoui L. , Attié J.-L. , Huszar P. , Szopa S. , Parmentier J. , Jaidan N. , Michou M. , Abida R. , Zbinden R. , Carminati F. , Hauglustaine D. , August T. , Warner J. , Imasu R. , Saitoh N. , Peuch V.-H.
Published: April 2014

Abstract. The space and time variabilities of methane (CH4) total column and upper tropospheric mixing ratios are analyzed above the Mediterranean Basin (MB) as part of the Chemical and Aerosol Mediterranean Experiment (ChArMEx) programme. Spaceborne measurements from the Thermal And Near infrared Sensor for carbon Observations-Fourier Transform Spectrometer (TANSO-FTS) instrument on the Greenhouse gases Observing SATellite (GOSAT) satellite, the Atmospheric InfraRed Spectrometer (AIRS) on the AURA platform and the Infrared Atmospheric Sounder Interferometer (IASI) instrument aboard the MetOp-A platform are used in conjunction with model results from the Chemical Transport Model (CTM) MOCAGE, and the Chemical Climate Models (CCMs) CNRM-AOCCM and LMDz-OR-INCA (according to different emission scenarios). In order to minimize systematic errors in the spaceborne measurements, we have only considered maritime pixels over the MB. The period under interest spans from 2008 to 2011 considering satellite and MOCAGE data and, regarding the CCMs, from 2001 to 2010. An East-West gradient in CH4 is observed and modelled whatever the season considered. In winter, air masses mainly originating from Atlantic Ocean and Europe tend to favour an elevated amount of mid-to-upper tropospheric CH4 in the West vs. the East of the MB, with a general upward transport above the MB. In summer, the meteorological state of the MB is changed, favouring air from Northern Africa and Middle East together with Atlantic Ocean and Europe, with a general downward motion above the MB. The Asian Monsoon traps and uplifts high amounts of CH4 that are transported towards North Africa and Middle East by the Asian Monsoon Anticyclone to finally reach and descent in the East of the MB. Consequently, the mid-to-upper tropospheric CH4 is much greater in the East than in the West of the MB. The seasonal variation of the difference in CH4 between the East and the West MB does show a maximum in summer for pressures from 500 to 100 hPa considering both spaceborne measurements and model results whatever the emission scenarios used. From this study, we can conclude that CH4 in the mid-to-upper troposphere over the MB is mainly affected by long-range transport, particularly intense in summer from Asia. In the low-to-mid troposphere, the local sources of emission in the vicinity of the MB mainly affect the CH4 variability.
Bayesian calibration of a soil organic carbon model using Δ14C measurements of soil organic carbon and heterotrophic respiration as joint constraints
Authors: Ahrens B. , Reichstein M. , Borken W. , Muhr J. , Trumbore S. E. , Wutzler T.
Published: April 2014

Abstract. Soils of temperate forests store significant amounts of organic matter and are considered to be net sinks of atmospheric CO2. Soil organic carbon (SOC) turnover has been studied using the Δ14C values of bulk SOC or different SOC fractions as observational constraints in SOC models. Further, the Δ14C values of CO2 that evolved during the incubation of soil and roots have been widely used together with Δ14C of total soil respiration to partition soil respiration into heterotrophic respiration (HR) and rhizosphere respiration. However, these data have not been used as joint observational constraints to determine SOC turnover times. Thus, we focus on (1) how different combinations of observational constraints help to narrow estimates of turnover times and other parameters of a simple two-pool model, the Introductory Carbon Balance Model (ICBM); (2) whether relaxing the steady-state assumption in a multiple constraints approach allows the source/sink strength of the soil to be determined while estimating turnover times at the same time. To this end ICBM was adapted to model SOC and SO14C in parallel with litterfall and the Δ14C of litterfall as driving variables. The Δ14C of the atmosphere with its prominent bomb peak was used as a proxy for the Δ14C of litterfall. Data from three spruce-dominated temperate forests in Germany and the USA (Coulissenhieb II, Solling D0 and Howland Tower site) were used to estimate the parameters of ICBM via Bayesian calibration. Key findings are as follows: (1) the joint use of all four observational constraints (SOC stock and its Δ14C, HR flux and its Δ14C) helped to considerably narrow turnover times of the young pool (primarily by Δ14C of HR) and the old pool (primarily by Δ14C of SOC). Furthermore, the joint use of all observational constraints made it possible to constrain the humification factor in ICBM, which describes the fraction of the annual outflux from the young pool that enters the old pool. The Bayesian parameter estimation yielded the following turnover times (mean ± standard deviation) for SOC in the young pool: Coulissenhieb II 1.1 ± 0.5 years, Solling D0 5.7 ± 0.8 years and Howland Tower 0.8 ± 0.4 years. Turnover times for the old pool were 377 ± 61 years (Coulissenhieb II), 313 ± 66 years (Solling D0) and 184 ± 42 years (Howland Tower), respectively. (2) At all three sites the multiple constraints approach was not able to determine if the soil has been losing or storing carbon. Nevertheless, the relaxed steady-state assumption hardly introduced any additional uncertainty for the other parameter estimates. Overall the results suggest that using Δ14C data from more than one carbon pool or flux helps to better constrain SOC models.
Remote sensing of annual terrestrial gross primary productivity from MODIS: an assessment using the FLUXNET La Thuile data set
Authors: Verma M. , Friedl M. A. , Richardson A. D. , Kiely G. , Cescatti A. , Law B. E. , Wohlfahrt G. , Gielen B. , Roupsard O. , Moors E. J. , Toscano P. , Vaccari F. P. , Gianelle D. , Bohrer G. , Varlagin A. , Buchmann N. , van Gorsel E. , Montagnani L. , Propastin P.
Published: April 2014

Abstract. Gross primary productivity (GPP) is the largest and most variable component of the global terrestrial carbon cycle. Repeatable and accurate monitoring of terrestrial GPP is therefore critical for quantifying dynamics in regional-to-global carbon budgets. Remote sensing provides high frequency observations of terrestrial ecosystems and is widely used to monitor and model spatiotemporal variability in ecosystem properties and processes that affect terrestrial GPP. We used data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and FLUXNET to assess how well four metrics derived from remotely sensed vegetation indices (hereafter referred to as proxies) and six remote sensing-based models capture spatial and temporal variations in annual GPP. Specifically, we used the FLUXNET La Thuile data set, which includes several times more sites (144) and site years (422) than previous studies have used. Our results show that remotely sensed proxies and modeled GPP are able to capture significant spatial variation in mean annual GPP in every biome except croplands, but that the percentage of explained variance differed substantially across biomes (10–80%). The ability of remotely sensed proxies and models to explain interannual variability in GPP was even more limited. Remotely sensed proxies explained 40–60% of interannual variance in annual GPP in moisture-limited biomes, including grasslands and shrublands. However, none of the models or remotely sensed proxies explained statistically significant amounts of interannual variation in GPP in croplands, evergreen needleleaf forests, or deciduous broadleaf forests. Robust and repeatable characterization of spatiotemporal variability in carbon budgets is critically important and the carbon cycle science community is increasingly relying on remotely sensing data. Our analyses highlight the power of remote sensing-based models, but also provide bounds on the uncertainties associated with these models. Uncertainty in flux tower GPP, and difference between the footprints of MODIS pixels and flux tower measurements are acknowledged as unresolved challenges.
Data compilation of fluxes of sedimenting material from sediment traps in the Atlantic Ocean
Authors: Torres Valdés S. , Painter S. C. , Martin A. P. , Sanders R. , Felden J.
Published: April 2014

Abstract. We provide a data set assemblage of directly observed and derived fluxes of sedimenting material (total mass, POC, PON, bSiO2, CaCO3, PIC and lithogenic/terrigenous fluxes) obtained using sediment traps. This data assemblage contains over 5900 data points distributed across the Atlantic, from the Arctic Ocean to the Southern Ocean. Data from the Mediterranean Sea are also included. Data were compiled from a variety of sources: data repositories (e.g. BCO-DMO, PANGAEA®), time-series sites (e.g. BATS, CARIACO), published scientific papers and data provided by the originating principal investigators (PIs). All sources are specified within the combined data set. Data from the World Ocean Atlas 2009 were extracted to coincide with flux data to provide additional environmental information where available. Specifically, contemporaneous data were extracted for temperature, salinity, oxygen (concentration, AOU and percentage saturation), nitrate, phosphate and silicate. Data show a broad range of flux estimates, with marked differences between ocean domains. Data also reveal important differences in the contribution that a given variable provides to the total mass flux, which is relevant towards understanding the factors that control the strength of the biological carbon pump. This data set has been submitted to the data repository PANGAEA® (http://www.pangaea.de), who have made it available under doi:10.1594/PANGAEA.807946.
Halley Research Station, Antarctica: calving risks and monitoring strategies
Authors: Anderson R. , Jones D. H. , Gudmundsson G. H.
Published: April 2014

Abstract. The British Antarctic Survey's Halley Research Station is located on the Brunt Ice Shelf, Antarctica, where it is potentially vulnerable to calving events. Existing historical records show that the Brunt Ice Shelf is currently extended further into the Weddell Sea than it was before its last large calving event, so a new calving event may be overdue. We describe three different possible future scenarios for a large-scale calving event on Brunt Ice Shelf. We conclude that currently the most threatening scenario for the Halley Research Station is a calving event on the neighbouring Stancomb-Wills Glacier Tongue, with subsequent detrimental consequences for the stability of the Brunt Ice Shelf. Based on available data, we suggest an increasing likelihood of this scenario occurring after 2020. We furthermore describe ongoing monitoring efforts aimed at giving advanced warning of an imminent calving event.
Metal Ion Levels Post Primary Unilateral Exeter Total Hip Arthroplasty
Authors: Vijaysegaran Praveen , Whitehouse Sarah L. , Bijoor Manu , English Hugh , Crawford Ross W.
Published: April 2014

Background

Metal ion release is common following total hip arthroplasty, yet postoperative levels have not been defined for most stems currently used in clinical practice.

Aim

To assess metal ion release in the serum of patients with well functioning unilateral Exeter V40 primary total hip arthroplasties one year after surgery.

Methods

Whole blood chromium and serum cobalt levels were measured in 20 patients following primary total hip arthroplasty with the Exeter V40 stem and a variety of acetabular components one year after surgery.

Results

Whole blood chromium levels were within the normal range (10-100 nmol/L), with a single mild elevation of serum cobalt (normal ≤20 nmol/L).

Conclusions

In well functioning primary unilateral total hip arthroplasty using the Exeter V40 stem with a variety of acetabular components one year post surgery, whole blood chromium levels are normal and serum cobalt elevations are rare and mild.
Traumax Screw Plate Vs. Gamma Nail. Blood Loss in Pertrochanteric Fractures Treated by Minimally Invasive Osteosynthesis
Authors: Reina Nicolas , Geiss Laurent , Pailhe Réegis , Maubisson Laurent , Laffosse Jean-Michel , Chiron Philippe
Published: April 2014

Purpose

This study is aimed to determine whether the Traumax dynamic hip screw reduces perioperative blood loss and transfusion rate compared to the Gamma nail in the treatment of pertrochanteric fractures.

Materials and Methods

A series of 331 patients were followed prospectively in a cohort study between February 2008 and October 2011 after a pertrochanteric fracture. Two types of fixation were used, 163 patients were treated with a Gamma nail and 168 patients with a minimally invasive screw plate Traumax. Perioperative blood loss, evaluated by the Mercuriali formula based on pre- and postoperative haemoglobin and transfusion rates were compared in order to assess risk factors.

Results

Increased perioperative blood loss was significantly linked with patient-related parameters (age, anticoagulant and platelet aggregation inhibitor treatment). Type of osteosynthesis and type of fracture were also risk factors for blood loss and transfusion. The Traumax group had significantly lower blood loss (347 ml vs. 577 ml) and transfusion rate (33.9% vs. 63.8%) than the Gamma group. Involvement of the greater trochanter increased the risk of blood loss only in the Gamma group. Functional results and bone healing were comparable at six months follow-up.

Conclusion

Screw plate Traumax significantly reduces perioperative bleeding after pertrochanteric fractures. It avoids fracture gaps that tend to maintain bleeding. Given the morbidity and complications related to acute anaemia and blood transfusion, the surgical management of these elderly patients is aided by this choice of fixation.
The Development and Nature of Femoral Head Cam Lesions following Acetabular Fractures
Authors: Berber Onur , Foote Julian , Sabharwal Sanjeeve , Datta Gorav , Bircher Martin D.
Published: April 2014

The aim of acetabular fracture fixation is to restore joint congruity with restoration of the articular surface. Poor outcomes are seen where this has not been achieved. Letournel reported a collarette osteophyte seen postoperatively in a proportion of patients, which he suggested was an early precursor to the development of osteoarthritis. This is a retrospective study of patients treated at a tertiary referral unit who developed this lesion. The triangular index was measured in 48 of these patients and then correlated with their clinical findings, Oxford Hip Score and the presence of os-teoarthritis. Length of follow-up, fracture classification, and joint congruency were also recorded. Results showed a statistically significant relationship between cam lesion size and the development of osteoarthritis (P = 0.008), cam lesion size and length of follow-up (P = 0.01), and between groin pain and postoperative joint congruency (LR = 0.035). These findings suggest that the appearance of a cam lesion is a poor long-term prognostic marker for the development of osteoarthritis in patients with an acetabular fracture.
Vastus Lateralis Transfer for Severe Hip Abductor Deficiency: A Salvage Procedure
Authors: Wang Kemble , Cole Stacey , White Dean C. , Armstrong Michael S.
Published: April 2014

Introduction

Abductor muscle deficiency can be a debilitating problem following hip arthroplasty surgery. We report outcomes of a novel method of abductor muscle function reconstruction surgery in patients with chronic, irreparable gluteus medius and minimus defects

Patients and Methods

Four consecutive patients who underwent our method of abductor reconstruction surgery were retrospectively reviewed. All patients had severe pain and positive Trendelenberg gait before surgery. Technique: the vastus lateralis (VL) muscle was raised on its neurovascular pedicle and transferred 12-14 centimetres by proximal translation. The proximal portion of VL was reattached via bony anchors to the external surface of the iliac wing just below the iliac crest. The distal portion of VL reattached to the lateral femoral shaft, lateral intermuscular septum, and the fascia of vastus intermedius.

Results

Average follow-up was 10 months (range 7-15 months). Three of the four patients report dramatic improvement in pain as measured by the visual analogue pain scale. The same three patients report being “extremely satisfied” with the pain relief achieved and “extremely satisfied” with the operation overall. Two patients reported being “extremely satisfied” with improvements in walking. Hip abduction power improved in all patients but to varying degrees.

conclusion

The results show that our method of VL transfer may be a viable option for patients with severe abductor deficiency. Modest but clinically relevant early results are seen.
A Multidisciplinary Enhanced Recovery Programme Allows Discharge within Two days of Total Hip Replacement; Three- to Five-Year Results of 100 Patients
Authors: Dawson-Bowling Sebastian J. , Jha Shilpa , Chettiar Krissen K. , East Debra J. , Gould Gerard C. , Apthorp Hugh D.
Published: April 2014

We present three- to five- year results of 100 sequential patients undergoing total hip replacement (THR) through a multidisciplinary rapid recovery programme, with mean length of stay (LOS) 1.99 nights.

Patients attend pre-admission ‘bone school’, with talks and assessments by the senior sister, physiotherapist and occupational therapist. All receive an uncemented Corail-Pinnacle THR via piriformis-sparing mini-posterior approach. ‘Low dose’ spinal plus light general anaesthesia provides sensory block whilst retaining motor function; painfree mobilisation is predictably achieved within four hours. Following radiograph and haemoglobin check next morning, patients are discharged on meeting specific nursing/physiotherapy criteria. Those within 20 miles receive outreach follow-up. Follow-up assessment is undertaken using SF36, Visual Analogue, Merle d'Aubigné-Postel and Oxford Hip Scores. Mean age was 65 years (25-91), mean BMI 28.7 (19-43). ASA ranged 1-3 (mode 2), Charlson comorbidity index from 0-9 (mode 3). Major complications were: one dislocation with deep infection; one myocardial infarction; one trochanteric bursitis requiring exploration; one ceramic fracture; and three metal debris reactions. Several more minor complications occurred. LOS was longer in older patients (p = 0.03) and those with higher Charlson index (p = 0.02).

Eighty-two patients remain under follow-up, (mean 37.8 months, range 36-61). Six have died; five underwent revision; seven have moved away or been lost. Ninety-seven percent remain quite or very satisfied.

Our LOS is amongst the shortest in the United Kingdom, with encouraging outcomes. The SSP succeeds by involving all team-members, and managing patient expectation. At a time of limited healthcare resources we propose that our SSP could readily be reproduced elsewhere with similar benefits.