bluuebunny/crossref_metadata_2025 huggingface dataset:
A TV-Based Iterative Regularization Method for the Solutions of Thermal Convection Problems
Authors: Chung Eric T. , Wong Jeff C.-F.
Published: May 2013

Linear/nonlinear and Stokes based-stabilizations for the filter equations for damping out primitive variable (PV) solutions corrupted by uniformly distributed random noises are numerically studied through the natural convection (NC) as well as the mixed convection (MC) environment. The most recognizable filter-scheme is based on a combination of the negative Laplace equation multiplied with the selection of the spatial scale and a linear function in order to preserve the uniqueness of the filtered solution. A more complicated filter-scheme, based on a Stokes problem which couples a filtered velocity and a filtered (artificial) pressure (or Lagrange multiplier) in order to enforce the incompressibility constraint, is also studied. Linear and Stokes based-filters via nested iterative (NI) filters and the consistent splitting scheme (CSS) are proposed for the NC/MC problems. Inspired by the total-variation (TV) model of image diffusion, well preserved feature flow patterns from the corrupted NC/MC environment are obtained by TV-Stokes based-filters together with the CSS. Our experimental results show that our proposed algorithms are effective and efficient in eliminating the unwanted spurious oscillations and preserving the accuracy of thermal convective fluid flows.
On Direct and Semi-Direct Inverse of Stokes, Helmholtz and Laplacian Operators in View of Time-Stepper-Based Newton and Arnoldi Solvers in Incompressible CFD
Authors: Vitoshkin H. , Gelfgat A. Yu.
Published: May 2013

Factorization of the incompressible Stokes operator linking pressure and velocity is revisited. The main purpose is to use the inverse of the Stokes operator with a large time step as a preconditioner for Newton and Arnoldi iterations applied to computation of steady three-dimensional flows and study of their stability. It is shown that the Stokes operator can be inversed within an acceptable computational effort. This inverse includes fast direct inverses of several Helmholtz operators and iterative inverse of the pressure matrix. It is shown, additionally, that fast direct solvers can be attractive for the inverse of the Helmholtz and Laplace operators on fine grids and at large Reynolds numbers, as well as for other problems where convergence of iterative methods slows down. Implementation of the Stokes operator inverse to time-stepping-based formulation of the Newton and Arnoldi iterations is discussed.
Classifying organic materials by oxygen-to-carbon elemental ratio to predict the activation regime of Cloud Condensation Nuclei (CCN)
Authors: Kuwata M. , Shao W. , Lebouteiller R. , Martin S. T.
Published: May 2013

Abstract. The governing highly soluble, slightly soluble, or insoluble activation regime of organic compounds as cloud condensation nuclei (CCN) was examined as a function of oxygen-to-carbon elemental ratio (O : C). New data were collected for adipic, pimelic, suberic, azelaic, and pinonic acids. Secondary organic materials (SOMs) produced by α-pinene ozonolysis and isoprene photo-oxidation were also included in the analysis. The saturation concentrations C of the organic compounds in aqueous solutions served as the key parameter for delineating regimes of CCN activation, and the values of C were tightly correlated to the O : C ratios. The highly soluble, slightly soluble, and insoluble regimes of CCN activation were found to correspond to ranges of [O : C] > 0.6, 0.2 < [O : C] < 0.6, and [O : C] < 0.2, respectively. These classifications were evaluated against CCN activation data of isoprene-derived SOM (O : C = 0.69–0.72) and α-pinene-derived SOM (O : C = 0.38–0.48). Isoprene-derived SOM had highly soluble activation behavior, consistent with its high O : C ratio. For α-pinene-derived SOM, although CCN activation can be modeled as a highly soluble mechanism, this behavior was not predicted by the O : C ratio, for which a slightly soluble mechanism was anticipated. Complexity in chemical composition, resulting in continuous water uptake and the absence of a deliquescence transition that can thermodynamically limit CCN activation, might explain the difference in the behavior of α-pinene-derived SOM compared to that of pure organic compounds. The present results suggest that atmospheric particles dominated by hydrocarbon-like organic components do not activate (i.e., insoluble regime) whereas those dominated by oxygenated organic components activate (i.e., highly soluble regime) for typical atmospheric cloud life cycles.
Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia
Authors: Edwards G. C. , Howard D. A.
Published: May 2013

Abstract. This paper presents the first gaseous elemental mercury (GEM) air-surface exchange measurements obtained over naturally enriched and background (<0.1 μg g−1 Hg) terrestrial landscapes in Australia. Two pilot field studies were carried out during the Australian autumn and winter periods at a copper-gold-cobalt-arsenic-mercury mineral field near Pulganbar, NSW. GEM fluxes using a dynamic flux chamber approach were measured, along with controlling environmental parameters over three naturally enriched and three background substrates. The enriched sites results showed net emission to the atmosphere and a strong correlation between flux and substrate Hg concentration, with average fluxes ranging from 14 ± 1 ng m−2 h−1 to 113 ± 6 ng m−2 h−1. Measurements at background sites showed both emission and deposition. The average Hg flux from all background sites showed an overall net emission of 0.36 ± 0.06 ng m−2 h−1. Fluxes show strong relationships with temperature, radiation, and substrate parameters. A compensation point of 2.48, representative of bare soils was determined. For periods of deposition, dry deposition velocities ranged from 0.00025 cm s−1 to 0.0083 cm s−1 with an average of 0.0041 ± 0.00018 cm s−1, representing bare soil, nighttime conditions. Comparison of the Australian data to North American data suggests the need for Australian-specific mercury air-surface exchange data representative of Australia's unique climatic conditions, vegetation types, land use patterns and soils.
Particle and gaseous emissions from individual diesel and CNG buses
Authors: Hallquist Å. M. , Jerksjö M. , Fallgren H. , Westerlund J. , Sjödin Å.
Published: May 2013

Abstract. In this study size-resolved particle and gaseous emissions from 28 individual diesel-fuelled and 7 compressed natural gas (CNG)-fuelled buses, selected from an in-use bus fleet, were characterised for real-world dilution scenarios. The method used was based on using CO2 as a tracer of exhaust gas dilution. The particles were sampled by using an extractive sampling method and analysed with high time resolution instrumentation EEPS (10 Hz) and CO2 with a non-dispersive infrared gas analyser (LI-840, LI-COR Inc. 1 Hz). The gaseous constituents (CO, HC and NO) were measured by using a remote sensing device (AccuScan RSD 3000, Environmental System Products Inc.). Nitrogen oxides, NOx, were estimated from NO by using default NO2/NOx ratios from the road vehicle emission model HBEFA3.1. The buses studied were diesel-fuelled Euro III–V and CNG-fuelled Enhanced Environmentally Friendly Vehicles (EEVs) with different after-treatment, including selective catalytic reduction (SCR), exhaust gas recirculation (EGR) and with and without diesel particulate filter (DPF). The primary driving mode applied in this study was accelerating mode. However, regarding the particle emissions also a constant speed mode was analysed. The investigated CNG buses emitted on average a higher number of particles but less mass compared to the diesel-fuelled buses. Emission factors for number of particles (EFPN) were EFPN, DPF = 4.4 ± 3.5 × 1014, EFPN, no DPF = 2.1 ± 1.0 × 1015 and EFPN, CNG = 7.8 ± 5.7 ×1015 kg fuel−1. In the accelerating mode, size-resolved emission factors (EFs) showed unimodal number size distributions with peak diameters of 70–90 nm and 10 nm for diesel and CNG buses, respectively. For the constant speed mode, bimodal average number size distributions were obtained for the diesel buses with peak modes of ~10 nm and ~60 nm. Emission factors for NOx expressed as NO2 equivalents for the diesel buses were on average 27 ± 7 g (kg fuel)−1 and for the CNG buses 41 ± 26 g (kg fuel)−1. An anti-relationship between EFNOx and EFPM was observed especially for buses with no DPF, and there was a positive relationship between EFPM and EFCO.
Impact of the North Atlantic Oscillation on the variations of aerosol ground levels through local processes over Europe
Authors: Jerez S. , Jimenez-Guerrero P. , Montávez J. P. , Trigo R. M.
Published: May 2013

Abstract. This contribution assesses non-antropogenic variations in ground-level aerosol concentrations over Europe associated to changes in the phase of the North Atlantic Oscillation (NAO). The NAO controls a large amount of the European climate variability with asymmetric impacts in both time and space. Based on simulated data and focusing on how the local atmospheric processes (without considering large-scale mechanisms) governed by the NAO affect the levels of various aerosol species, this study highlights that positive NAO phases favor increased aerosols levels in southern (northern) regions in winter (summer), while negative NAO phases enhance them in northern (southern) regions in winter (summer). Variations are up to and over 100% for most aerosols, being clearly related to the NAO-impact on precipitation and wind, as they act to clean the atmosphere through removal and dispersion processes, and to the NAO-impact on the radiation balance (i.e. cloudiness) as it rebounds on the biogenic emitting activity and on the oxidative capacity of the atmosphere. Beyond deepening on the understanding of fundamental interactions between climate and air quality, these results provide a basis for improving the potential predictability of this later since much work is being done in order to gain accuracy in the NAO predictions.
Aircraft type influence on contrail properties
Authors: Jeßberger P. , Voigt C. , Schumann U. , Sölch I. , Schlager H. , Kaufmann S. , Petzold A. , Schäuble D. , Gayet J.-F.
Published: May 2013

Abstract. The investigation of the impact of aircraft parameters on contrail properties helps to better understand the climate impact from aviation. Yet, in observations, it is a challenge to separate aircraft and meteorological influences on contrail formation. During the CONCERT campaign in November 2008, contrails from 3 Airbus passenger aircraft of type A319-111, A340-311 and A380-841 were probed at cruise under similar meteorological conditions with in-situ instruments on board the DLR research aircraft Falcon. Within the 2 min old contrails detected near ice saturation, we find similar effective diameters Deff (5.2–5.9 μm), but differences in particle number densities nice (162–235 cm−3) and in vertical contrail extensions (120–290 m), resulting in large differences in contrail optical depths τ (0.25–0.94). Hence larger aircraft produce optically thicker contrails. Based on the observations, we apply the EULAG-LCM model with explicit ice microphysics and in addition the Contrail and Cirrus Prediction model CoCiP to calculate the aircraft type impact on young contrails under identical meteorological conditions. The observed increase in τ for heavier aircraft is confirmed by the models, yet for generally smaller τ. An aircraft dependence of climate relevant contrail properties persists during contrail lifetime, adding importance to aircraft dependent model initialization. We finally derive an analytical relationship between contrail, aircraft and meteorological parameters. Near ice saturation, contrail width × τ scales linearly with fuel flow rate as confirmed by observations. For higher saturation ratios approximations from theory suggest a non-linear increase in the form (RHI–1)2/3. Summarized our combined results could help to more accurately assess the climate impact from aviation using an aircraft dependent contrail parameterization.
Coral Patch seamount (NE Atlantic) – a sedimentological and megafaunal reconnaissance based on video and hydroacoustic surveys
Authors: Wienberg C. , Wintersteller P. , Beuck L. , Hebbeln D.
Published: May 2013

Abstract. The present study provides new knowledge about the so far largely unexplored Coral Patch seamount which is located in the NE Atlantic Ocean half-way between the Iberian Peninsula and Madeira. For the first time a detailed hydroacoustic mapping (MBES) in conjunction with video surveys (ROV, camera sled) were performed to describe the sedimentological and biological characteristics of this sub-elliptical ENE-WSW elongated seamount. Video observations were restricted to the southwestern summit area of Coral Patch seamount (water depth: 560–760 m) and revealed that this part of the summit is dominated by exposed hard substrate, whereas soft sediment is just a minor substrate component. Although exposed hardgrounds are dominant for this summit area and, thus, offer suitable habitat for settlement by benthic organisms, the benthic megafauna shows rather scarce occurrence. In particular, scleractinian framework-building cold-water corals are apparently rare with very few isolated and small-sized live occurrences of the species Lophelia pertusa and Madrepora oculata. In contrast, dead coral framework and coral rubble are more frequent pointing to a higher abundance of cold-water corals on Coral Patch during the recent past. This is even supported by the observation of fishing lines that got entangled with rather fresh-looking coral frameworks. Overall, long lines and various species of commercially important fish were frequently observed emphasising the potential of Coral Patch as an important target for fisheries that may have impacted the entire benthic community. Hydroacoustic seabed classification covered the entire summit of Coral Patch and its northern and southern flanks (water depth: 560–2660 m) and revealed extended areas dominated by mixed and soft sediments at the northern flank and to a minor degree at its easternmost summit and southern flank. Nevertheless, these data also predict most of the summit area to be dominated by exposed bedrock which would offer suitable habitat for benthic organisms. By comparing the locally restricted video observations and the broad-scale monitoring of a much larger and deeper seafloor area as derived by hydroacoustic seabed classification, it becomes obvious that habitat information obtained by in situ sampling may provide a rather scattered pattern about the entire seamount ecosystem. Solely with a combination of both methods, a satisfactory approach to describe the diverse characteristics of a seamount ecosystem can be derived which is in turn indispensable for future scientific monitoring campaigns as well as management and conservation purposes.
Where to find 1.5 million yr old ice for the IPICS "Oldest Ice" ice core
Authors: Fischer H. , Severinghaus J. , Brook E. , Wolff E. , Albert M. , Alemany O. , Arthern R. , Bentley C. , Blankenship D. , Chappellaz J. , Creyts T. , Dahl-Jensen D. , Dinn M. , Frezzotti M. , Fujita S. , Gallee H. , Hindmarsh R. , Hudspeth D. , Jugie G. , Kawamura K. , Lipenkov V. , Miller H. , Mulvaney R. , Pattyn F. , Ritz C. , Schwander J. , Steinhage D. , van Ommen T. , Wilhelms F.
Published: May 2013

Abstract. The recovery of a 1.5 Myr long ice core from Antarctica represents a keystone to our understanding of Quaternary climate, the progression of glaciation over this time period and the role of greenhouse gas cycles in this progression. Here we show that such old ice is most likely to exist in the plateau area of the East Antarctic Ice Sheet (EAIS) without stratigraphic disturbance and should be able to be recovered after careful pre-site selection studies. Based on a simple ice and heat flow model and glaciological observations, we conclude that positions in the vicinity of major domes and saddle positions on the East Antarctic Plateau will most likely have such old ice in store and represent the best study areas for dedicated reconnaissance studies in the near future. In contrast to previous ice core drill site selections, we strongly argue for significantly reduced ice thickness to avoid bottom melting, while at the same time maximizing the resolution and the distance of such old ice to the bedrock. For example for the geothermal heat flux and accumulation conditions at Dome C, an ice thickness lower than 2500 m would be required to find 1.5 Myr old ice. However, the final choice is strongly dependent on the local geothermal heat flux, which is largely unknown for the EAIS and has to be determined beforehand. In addition, the detailed bedrock topography and ice flow history for candidates of an Oldest Ice ice coring site has to be reconstructed. Finally, we argue strongly for rapid access drilling before any full deep ice coring activity commences to bring datable samples to the surface and to allow an age check of the oldest ice.
High resolution measurements of carbon monoxide along a late Holocene Greenland ice core: evidence for in-situ production
Authors: Faïn X. , Chappellaz J. , Rhodes R. H. , Stowasser C. , Blunier T. , McConnell J. R. , Brook E. J. , Preunkert S. , Legrand M. , Desbois T. , Romanini D.
Published: May 2013

Abstract. We present high-resolution measurements of carbon monoxide (CO) concentrations from continuous analysis of a shallow ice core from the North Greenland Eemian Ice Drilling project (NEEM-2011-S1). An Optical Feedback – Cavity Enhanced Absorption Spectrometer (OF-CEAS) was coupled to a continuous melter system during a 4-week laboratory-based measurement campaign. This analytical setup generates highly stable measurements of CO concentrations with an external precision of 7.8 ppbv (1 sigma) based on a comparison of replicate cores. The NEEM-2011-S1 CO record spans 1800 yr and exhibits highly variable concentrations at the scale of annual layers, ranging from 75 to 1327 ppbv. The most recent section of this record (i.e. since 1700 AD) agrees with existing discrete CO measurements from the Eurocore ice core and the deep NEEM firn. However, it is difficult to interpret in terms of atmospheric CO variation due to high frequency, high amplitude spikes in the data. 68% of the elevated CO spikes are observed in ice layers enriched with pyrogenic aerosols. Such aerosols, originating from boreal biomass burning emissions, contain organic compounds, which can be oxidized or photodissociated to produce CO in-situ. We suggest that elevated CO concentration features could present a new integrative proxy for past biomass burning history. Furthermore, the NEEM-2011-S1 record reveals an increase in baseline CO level prior to 1700 AD (129 m depth), with the concentration remaining high even for ice layers depleted in dissolved organic carbon (DOC). Overall, the processes driving in-situ production of CO within the NEEM ice are complex and may involve multiple chemical pathways.
Effects of network pressure on water meter under-registration: an experimental analysis
Authors: Fontanazza C. M. , Notaro V. , Puleo V. , Freni G.
Published: May 2013

Abstract. In water supply systems, a considerable amount of apparent loss is caused by meter under-registration. Water meters are subject to intrinsic systemic error depending on the actual flow rates passing through them. Furthermore, the moving parts of the meter are subject to wear and tear that progressively reduce meter accuracy. The increase in systemic error is especially evident at low flow rates because of growing friction in the rotating mechanism, which requires a higher flow to start the meter (starting flow). The aim of this paper is to experimentally investigate metering error in an attempt to find a direct link between meter age, network pressure and apparent losses caused by the inability of the meter to accurately register the volume passing though it at low flow rates. The study was performed through laboratory experiments in which worn-out water meters were tested using a test bench. The results of the laboratory experiments show that ageing and pressure are both relevant parameters for determining meter starting flow. These results were then applied to assess the effects on apparent losses of the age of the meter, varying pressure values upstream of the meter (the pressure in the network where the meter is installed) and different patterns of flow rates passing through the device (the consumption pattern of the user). The presented results are useful for understanding the effects of operating conditions on water meter under-registration, which can aid water managers in implementing effective replacement campaigns.
Permafrost temperature and active-layer thickness of Yakutia with 0.5 degree spatial resolution for model evaluation
Authors: Beer C. , Fedorov A. N. , Torgovkin Y.
Published: May 2013

Abstract. Based on the map of landscapes and permafrost conditions in Yakutia (Merzlotno-landshaftnaya karta Yakutskoi0 ASSR, Gosgeodeziya SSSR, 1991), rasterized maps of permafrost temperature and active-layer thickness of Yakutia, East Siberia were derived. The mean and standard deviation at 0.5 degree grid cell size are estimated by assigning a probability density function at 0.001 degree spatial resolution. The gridded datasets can be accessed at the PANGAEA repository (doi:10.1594/PANGAEA.808240). Spatial pattern of both variables are dominated by a climatic gradient from north to south, and by mountains and the soil type distribution. Uncertainties are highest in mountains and in the isolated permafrost zone in the south. The maps are best suited as a benchmark for land surface models which include a permafrost module.
Global database of surface ocean particulate organic carbon export fluxes diagnosed from the 234Th technique
Authors: Le Moigne F. A. C. , Henson S. A. , Sanders R. J. , Madsen E.
Published: May 2013

Abstract. The oceanic biological carbon pump is an important factor in the global carbon cycle. Organic carbon is exported from the surface ocean mainly in the form of settling particles derived from plankton production in the upper layers of the ocean. The large variability in current estimates of the global strength of the biological carbon pump emphasises that our knowledge of a major planetary carbon flux remains poorly constrained. We present a database of 723 estimates of organic carbon export from the surface ocean derived from the 234Th technique. The dataset is archived on the data repository PANGEA® (www.pangea.de) under doi:10.1594/PANGAEA.809717. Data were collected from tables in papers published between 1985 and early 2013 only. We also present sampling dates, publication dates and sampling areas. Most of the open ocean provinces are represented by several measurements. However, the Western Pacific, the Atlantic Arctic, South Pacific and the South Indian Ocean are not well represented. There is a variety of integration depths ranging from surface to 220 m. Globally the fluxes ranged from 0 to 1500 mg of C m−2 d−1.
Analysis of long-term terrestrial water storage variations in the Yangtze River basin
Authors: Huang Y. , Salama M. S. , Krol M. S. , van der Velde R. , Hoekstra A. Y. , Zhou Y. , Su Z.
Published: May 2013

Abstract. In this study, we analyze 32 yr of terrestrial water storage (TWS) data obtained from the Interim Reanalysis Data (ERA-Interim) and Noah model from the Global Land Data Assimilation System (GLDAS-Noah) for the period 1979 to 2010. The accuracy of these datasets is validated using 26 yr (1979–2004) of runoff data from the Yichang gauging station and comparing them with 32 yr of independent precipitation data obtained from the Global Precipitation Climatology Centre Full Data Reanalysis Version 6 (GPCC) and NOAA's PRECipitation REConstruction over Land (PREC/L). Spatial and temporal analysis of the TWS data shows that TWS in the Yangtze River basin has decreased significantly since the year 1998. The driest period in the basin occurred between 2005 and 2010, and particularly in the middle and lower Yangtze reaches. The TWS figures changed abruptly to persistently high negative anomalies in the middle and lower Yangtze reaches in 2004. The year 2006 is identified as major inflection point, at which the system starts exhibiting a persistent decrease in TWS. Comparing these TWS trends with independent precipitation datasets shows that the recent decrease in TWS can be attributed mainly to a decrease in the amount of precipitation. Our findings are based on observations and modeling datasets and confirm previous results based on gauging station datasets.
Comparative analysis of hydrologic signatures in two agricultural watersheds in east-central Illinois: legacies of the past to inform the future
Authors: Yaeger M. A. , Sivapalan M. , McIsaac G. F. , Cai X.
Published: May 2013

Abstract. Historically, the central Midwestern US has undergone drastic anthropogenic land use change, having been transformed, in part through federal government policy, from a natural grassland system to an artificially-drained agricultural system devoted to row cropping corn and soybeans. Current federal policies are again influencing land use change in this region with increased corn acreage and new biomass crops proposed as part of an energy initiative emphasizing biofuels. To better address these present and future challenges it is helpful to understand how the legacies of past changes have shaped the current response of the system. To this end, a comparative analysis of the hydrologic signatures in both spatial and time series data from two central Illinois watersheds was undertaken. The past history of these catchments is reflected in their current hydrologic responses, which are highly heterogeneous, more so in the extensively tile-drained Sangamon watershed. The differences in geologic history, artificial drainage patterns, and to some extent, reservoir construction, manifest at all time scales, from annual to daily, and spatially within the watersheds. These differences can also be seen in the summer low flow patterns, where the more tile-drained watershed shows more variability than does the more naturally drained one. Of interest is the scaling behavior of the low flows; generally as drainage area increases, small-scale heterogeneity decreases. This is not seen in the more tile-drained watershed, thus adding complexity to the problem of predicting the catchment response to future changes.
Spatiotemporal characterization of dissolved carbon for inland waters in semi-humid/semiarid region, China
Authors: Song K. S. , Zang S. Y. , Zhao Y. , Du J. , Li L. , Zhang N. N. , Wang X. D. , Shao T. T. , Guan Y. , Liu L.
Published: May 2013

Abstract. Spatiotemporal variations of dissolved organic carbon (DOC), inorganic carbon (DIC) in 26 waters across the semi-humid/semi-arid Songnen Plain, China were examined with data collected during 2008–2011. Fresh (n = 14) and brackish (n = 12) waters were grouped according to electrical conductivity (threshold = 1000 μS cm−1). Significant differences in the mean DOC/DIC concentrations were observed between fresh (5.63 mg L−1, 37.39 mg L−1) and brackish waters (15.33 mg L−1, 142.93 mg L−1). Colored dissolved organic matter (CDOM) and DOC concentrations were mainly controlled by climatic-hydrologic conditions. The observation indicated that the outflow conditions in the semi-endorheic region had condensed effects on the dissolved carbon, resulting in close relationships between salinity vs. DOC (R2 = 0.66), and vs. DIC (R2 = 0.94). Independent data set collected in May 2012 also confirmed this finding (DOC: R2 = 0.79), (DIC: R2 = 0.91), highlighting the potential of quantifying DOC/DIC via salinity measurements for waters dispersed in the plain. Indices based on CDOM absorption spectra, e.g. DOC specific CDOM absorption (SUVA254), absorption ratio a250 : a365 (E250:365) and spectral slope ratio (Sr, S275−295/S350−400), were applied to characterize DOM composition and quality. Our results indicate high molecular weight CDOM fractions are more abundant in fresh waters than brackish waters.
Revision Hip Arthroplasty with an Extensively Porous-coated Stem - Excellent Long-term Results Also in Severe Femoral Bone Stock Loss
Authors: Thomsen Per B. , Jensen Niels J.F. , Kampmann Jens , Hansen Torben Bæk
Published: May 2013

During the last 25 years uncemented hip stem revision relying on diaphyseal fixation has shown improving clinical results and stem survival. The purpose of this study was to present the long-term results of hip revision with the SOLUTION stem (DePuy Warsaw Indiana).

Ninety-three consecutive SOLUTION hip stem revisions in 84 patients with a mean age of 69 years (range 33-86 years) were reviewed. Of these, clinical and radiographic follow-up examination by an independent observer was possible in 36 hips/29 patients after mean 14 years (range 10-18 years). Stem re-revision was documented by our own files and by the Danish Hip Arthroplasty Registry.

Stem re-revision had been performed in two hips for aseptic loosening, one due to deep infection and in one patient due to stem fracture. The 18 years cumulative survival, free of re-revision for any reason was calculated as 94.4% (88.9-99.8)% and for aseptic loosening to 97.6% (94.3-100%). Intraoperative complications were frequent with incidence of shaft fractures (14/93) and perforations (9/93) showing a significant learning curve. Mean Harris Hip Score was 85 (range 53-99). Osseointegration was seen in 34/36 stems with two stems fibrous fixated. Stress shielding was significant associated with stem diameters ≥15 mm. Severe preoperative bone deficiency had no negative bearing on stem survival and no significant influence on osseointegration of the stem or on Harris Hip Score.

Conclusion:

Femoral stem revision with an extensively porous-coated monoblock chrome-cobalt stem seems to be a reliable and reproducible technique resulting in excellent long-term survivorship and clinical outcome. It can be used in femurs with deficient bone stock.
HSV-1 as a Model for Emerging Gene Delivery Vehicles
Authors: Lim Filip
Published: May 2013

The majority of viral vectors currently used possess modest cargo capability (up to 40 kb) being based on retroviruses, lentiviruses, adenoviruses, and adenoassociated viruses. These vectors have made the most rapid transition from laboratory to clinic because their small genomes have simplified their characterization and modification. However, there is now an increasing need both in research and therapy to complement this repertoire with larger capacity vectors able to deliver multiple transgenes or to encode complex regulatory regions, constructs which can easily span more than 100 kb. Herpes Simplex Virus Type I (HSV-1) is a well-characterized human virus which is able to package about 150 kb of DNA, and several vector systems are currently in development for gene transfer applications, particularly in neurons where other systems have low efficiency. However, to reach the same level of versatility and ease of use as that of smaller genome viral vectors, simple systems for high-titer production must be developed. This paper reviews the major HSV-1 vector systems and analyses the common elements which may be most important to manipulate to achieve this goal.
The Diagnostic Yield of Navigational Bronchoscopy Performed with Propofol Deep Sedation
Authors: Mohanasundaram Uma , Ho Lawrence A. , Kuschner Ware G. , Chitkara Rajinder K. , Canfield James , Canfield Lourdes M. , Krishna Ganesh
Published: May 2013

Objective. To describe the diagnostic yield of electromagnetic navigation bronchoscopy (ENB) utilizing propofol for procedural deep sedation. Methods. We conducted a structured retrospective analysis of the medical records of patients who underwent ENB with propofol for the evaluation of pulmonary nodules and masses. We analyzed the relationships between lesion size and location, variance (CT-to-body divergence), and positron emission tomography findings on diagnostic yield. Diagnoses were established by histopathological evaluation and clinical-radiographic followup. Results. 41 patients underwent ENB during the study period. The overall diagnostic yield was 89% (42 of 47 target lesions). Among the 42 positive specimens, the diagnoses were squamous cell carcinoma (n=10), adenocarcinoma (n=14), small cell carcinoma (n=2), adenocarcinoma in situ (n=2), coccidioidomycosis (n=1), and inflammatory processes (n=13). Average lesion size was 3.01±0.21 cm and variance 3.6±0.15 mm. The diagnostic yield was greater when the lesion size was >4 cm (100%) and when variance was ≤4 mm (91% versus 87%, P=0.003). Conclusion. The diagnostic yield of ENB utilizing propofol for procedural deep sedation at our center was excellent. ENB with deep sedation may result in superior diagnostic yield compared with ENB performed with moderate sedation.
Predicting the risk of recurrent venous thromboembolism
Authors: Eischer L. , Kyrle P. A.
Published: May 2013

Venous thromboembolism (VTE) is a disease, which often recurs. The recurrence risk is highest in patients with unprovoked proximal deep-vein thrombosis (VT) or pulmonary embolism. Men have a higher risk than women. The risk is low in patients with VTE related to a temporary risk factor such as surgery or estrogen use. Other risk factors include overweight, post-thrombotic syndrome, history of VTE, residual VT or a vena cava filter.

Both factor V Leiden and the prothrombin mutation confer a negligible increase in recurrence risk. High clotting factor levels, deficiency of a natural coagulation inhibitor, or hyperhomocysteinaemia are also associated with an increased risk. Reasons why routine laboratory thrombophilia screening however is no longer warranted are addressed in this article. Prediction rules combining clinical characteristics and coagulation assays have recently been developed. One such model, the Vienna Prediction Model, allows predicting recurrent VTE on the basis of VTE location, sex and D-dimer. This article describes strategies to distinguish between patients with high risk of recurrent VTE from those with a lower risk, who might not benefit from long-term antithrombotic therapy.
Quality Assessment of Lightly Salted Atlantic Salmon Fillets Injected With Brine Solutions Containing Sodium Bicarbonate
Authors: Åsli Magnus , Rødbotten Marit , Vogt Gjermund , Afanasyev Sergey , Mørkøre Turid
Published: May 2013

The objective of this study was to produce lightly salted Atlantic salmon (Salmo salar L.) fillets with improved technical and sensory attributes. Brine containing 0, 50, 150 or 250 g/L NaCl with or without additional 25 g/L sodium bicarbonate (NaHCO3) was injected into the fillets. 24 hours after injection, the muscle NaCl concentration ranged from 0.2 to 2.4%, and pH ranged from 6.18 to 6.48. Untreated fillets lost 1% weight, whereas the weight increase was 4% of the fillets injected with NaCl or a combination of NaCl and NaHCO3. Liquid loss (LL) during storage at 4°C for three days were similar for the untreated fillets and the fillets injected with 50 g/L NaCl (LL 12%), while LL was reduced to 7.5% with the addition of NaHCO3 to the 50 g/L brine. LL was the lowest for the groups injected with 250 g/L NaCl. Injection of NaCl resulted in higher lipid oxidation compared with untreated fillets, determined as doubled levels of alkanals (4.3 vs. 10.4 ng/g) and pentenols (8.0 vs. 15.1 ng/g), but addition of NaHCO3 counteracted the action of NaCl as a pro-oxidant. Furthermore, NaHCO3 addition of the 50 g/L brine significantly improved the color of raw and cooked fillets (higher a*-value, Salmo Fan score, red/orange color tone). Sensory assessment of cooked fillet revealed that brine added NaHCO3 gave superior odor (less rancid), flavor (less metallic) and higher scores for tenderness. In conclusion, addition of NaHCO3 to the brine solutions improved liquid retention, storage stability, color, odor and flavor of lightly salted salmon fillets.
Plackett-Burman Experimental Design for Investigating the Effect of Porcine Plasma Protein, Trehalose and Bovine Meat Protein Isolate on Cook Yield and Texture of Minced Bovine Meat
Authors: Patroklos Vareltzis , Dimitris Petridis , Petropoulou Argiro , Fani Tsamitropoulou
Published: May 2013

A common additive to counter the cooking losses considerations in the muscle food industry is sodium tripolyphosphate (STP), which however may pose health risk for certain segments of the population. This paper employs a Plackett-Burman design to investigate the effect of porcine plasma protein (PPP), protein isolate from bovine meat (PI), trehalose and pH of the additive mixture on cook yield and textural characteristics of minced beef during frozen storage. Results show that PI and PPP significantly (p < 0.05) increase the cooking yield throughout the storage period compared to the control sample. Fresh samples with PPP, PI and STP had ~90% cooking yield, while control sample had only 75%. PI and PPP can improve the cooking yield of minced beef for the first two months of storage by at least 20%, in a similar and comparable pattern with STP. Upon optimization the optimal values were achieved at PI concentration 2.3-5.0% and PPP levels 1.7-4.7%.
Phytochemicals in Edible Wild Mushrooms From Selected Areas in Kenya
Authors: Wandati T. W. , Kenji G. M. , Onguso J. M.
Published: May 2013

Mushrooms have been used as food for centuries all over the world because of their characteristic soft texture and mild flavor. They are documented as being good source of nutrients and bioactive compounds that are beneficial to the human body (Chang, 2011). While the exotic varieties have been extensively analyzed, local edible wild mushrooms have not and yet they are consumed by communities living near the forests. This research aimed at screening and determination of phytochemicals compounds in wild edible mushroom found in selected areas in Kenya Two commercially grown mushrooms, oyster (Pleurotus florida) and button (Agaricus bisporus), and ten edible wild mushrooms species were collected from different locations of the country. They were analyzed for total polyphenols, flavonoids and radical scavenging activity using standard methods. All the analysis was done in triplicate. Phytochemical screening showed presence of saponins, polyphenols and terpenoids. Total polyphenols values obtained ranged between 210-1614 mg Gallic Acid equivalent (GAE)/100g, dry weight basis (dwb) and flavonoids 214-1695 mg Quercetin Equivalent (QE)/100 g dwb. Total polyphenols (R2 = 0.82, P ? 0.05) and flavonoids values showed a positive correlation with the radical scavenging activity.
 The results show that cultivated and wild edible mushrooms are rich in health-promoting phytochemical compounds.
The Importance of a Conchal Bowl Element in the Fabrication of a Three-Dimensional Framework in Total Auricular Reconstruction
Authors: Kim Young Soo
Published: May 2013

Background To construct a sophisticated three-dimensional framework, numerous modifications have been reported in the literature. However, most surgeons have paid little attention to the anatomical configuration of the concha and more to its deepness and hollowness, leading to unsatisfactory outcomes.

Methods For a configuration of the concha that is definitely anatomical, the author further developed and employed the conchal bowl element, which has been used by several surgeons although the results have not been published elsewhere. The author constructed the conchal bowl element in one of three patterns according to the amount of available cartilages: one block, two-pieces, or a cymba bowl element only. A total of 20 patients underwent auricular reconstruction using a costal cartilage framework between 2009 and 2012. The 8 earliest reconstructions were performed without a conchal bowl element and the latter 12 with a conchal bowl element. The patients were followed up for more than 1 year. The aesthetic results were scored by evaluating characteristics involving the stability of the crus helicis, the conchal definition, and the smoothness of the helical curve.

Results The ears reconstructed early without a conchal bowl element showed a shallow and one or two incompletely separated concha with an obliterated cymba conchal space. They also did not have a realistic or smooth curve of the helix because of an unstable crus helicis. However, ears reconstructed later with the concha bowl element showed a definite crus helicis, deep cymba conchal space, and smooth helical curve.

Conclusions The construction of the conchal bowl element is simple, not time-consuming procedure. It is suggested that the conchal bowl element must be constructed and attached to the main framework for natural configuration of the reconstructed ear.
Impact of Disturbed Wound Healing after Surgery on the Prognosis of Marjolin's Ulcer
Authors: Choi Jae Yeon , Bae Yong Chan , Nam Su Bong , Bae Seong Hwan
Published: May 2013

Background Marjolin's ulcer is known to present a high proportion of recurrence and poor prognosis compared to other kinds of skin cancer. Based on our experience, Marjolin's ulcer patients who have received reconstructive surgery present a higher proportion of recurrence when there was disturbed wound healing after surgery. The impact of disturbed wound healing after surgery on the prognosis was examined in this study.

Methods A retrospective study was carried out on 26 patients who were diagnosed with Marjolin's ulcer and received surgery in this hospital from 1996 to 2011. Histologic grading, lymph node metastasis at diagnosis, and the wound healing process were evaluated and chi-squared analysis applied in order to determine the correlation with recurrence.

Results The proportion of recurrence increases in patients with a low histologic grade or lymph node metastasis at diagnosis. The proportion of recurrence is even higher when the problem occurs during the wound healing process after surgery.

Conclusions Disturbed wound healing after surgery could be used as a sign to quickly identify the recurrence of carcinoma. Therefore, in the event a problem occurs in the wound healing process after surgery, one should keep in mind that this could be a sign of the possibility of recurrence and proceed with careful observation and active diagnosis through additional physical examinations, general X-ray tests, computed tomographys, magnetic resonance imagings, and so on, to obtain an early diagnosis of recurrence.
Magnetic Resonance Imaging-Based Volumetric Analysis and Its Relationship to Actual Breast Weight
Authors: Yoo Anna , Minn Kyung Won , Jin Ung Sik
Published: May 2013

Background Preoperative volume assessment is useful in breast reconstruction. Magnetic resonance imaging (MRI) and mammography are commonly available to reconstructive surgeons in the care of a patient with breast cancer. This study aimed to verify the accuracy of breast volume measured by MRI, and to identify any factor affecting the relationship between measured breast volume and actual breast weight to derive a new model for accurate breast volume estimation.

Methods From January 2012 to January 2013, a retrospective review was performed on a total of 101 breasts from 99 patients who had undergone total mastectomy. The mastectomy specimen weight was obtained for each breast. Mammographic and MRI data were used to estimate the volume and density. A standard statistical analysis was performed.

Results The mean mastectomy specimen weight was 340.8 g (range, 95 to 795 g). The mean MRI-estimated volume was 322.2 mL3. When divided into three groups by the "difference percentage value", the underestimated group showed a significantly higher fibroglandular volume, higher percent density, and included significantly more Breast Imaging, Reporting and Data System mammographic density grade 4 breasts than the other groups. We derived a new model considering both fibroglandular tissue volume and fat tissue volume for accurate breast volume estimation.

Conclusions MRI-based breast volume assessment showed a significant correlation with actual breast weight; however, in the case of dense breasts, the reconstructive surgeon should note that the mastectomy specimen weight tends to overestimate the volume. We suggested a new model for accurate breast volume assessment considering fibroglandular and fat tissue volume.
Evaluation of the Microvascular Research Center Training Program for Assessing Microsurgical Skills in Trainee Surgeons
Authors: Komatsu Seiji , Yamada Kiyoshi , Yamashita Shuji , Sugiyama Narushi , Tokuyama Eijiro , Matsumoto Kumiko , Takara Ayumi , Kimata Yoshihiro
Published: May 2013

Background We established the Microvascular Research Center Training Program (MRCP) to help trainee surgeons acquire and develop microsurgical skills. Medical students were recruited to undergo the MRCP to assess the effectiveness of the MRCP for trainee surgeons.

Methods Twenty-two medical students with no prior microsurgical experience, who completed the course from 2005 to 2012, were included. The MRCP comprises 5 stages of training, each with specific passing requirements. Stages 1 and 2 involve anastomosing silicone tubes and blood vessels of chicken carcasses, respectively, within 20 minutes. Stage 3 involves anastomosing the femoral artery and vein of live rats with a 1-day patency rate of >80%. Stage 4 requires replantation of free superficial inferior epigastric artery flaps in rats with a 7-day success rate of >80%. Stage 5 involves successful completion of one case of rat replantation/transplantation. We calculated the passing rate for each stage and recorded the number of anastomoses required to pass stages 3 and 4.

Results The passing rates were 100% (22/22) for stages 1 and 2, 86.4% (19/22) for stage 3, 59.1% (13/22) for stage 4, and 55.0% (11/20) for stage 5. The number of anastomoses performed was 17.2±12.2 in stage 3 and 11.3±8.1 in stage 4.

Conclusions Majority of the medical students who undertook the MRCP acquired basic microsurgical skills. Thus, we conclude that the MRCP is an effective microsurgery training program for trainee surgeons.
Versatility of the Distally-Based Sural Artery Fasciocutaneous Flap on the Lower Leg and Foot in Patients with Chronic Disease
Authors: Park Jin-Su , Roh Si-Gyun , Lee Nae-Ho , Yang Kyoung-Moo
Published: May 2013

Background A recent advancement in microsurgery, the free flap is widely used in the reconstruction of the lower leg and foot. The simple and effective methods of local flaps, including transposition and advancement flaps, have been considered for patients with chronic debilitation who are unable to endure long surgical procedures or general anesthesia. However, the location and size of the wound may restrict the clinical application of a local flap. Under these circumstances, a sural flap can be an excellent alternative, rendering satisfying clinical outcomes in chronically debilitated patients.

Methods Between 2008 and 2012, 39 patients underwent soft tissue defect treatment by sural artery flap as a final method. All of the patients had at least one chronic disease or more (diabetes, hypertension, vascular disease, etc.). Also, all of the patients had a history of chronic lower extremity ulceration, which revealed no response to several months of conservative treatment.

Results The results of the 39 cases had a success rate of 100% with 39 complete recoveries. Nine cases suffered complications: partial necrosis (n=4), wound dehiscence without necrosis (n=3), hematoma (n=1), and infection (n=1).

Conclusions The sural artery flap is not only useful for the lower leg but also for the heel, and other various parts. Furthermore, it is a relatively simple surgical technique for reconstructing the defect area for patients with various chronic conditions with a high surgical risk or contraindications to surgery.