bluuebunny/crossref_metadata_2025 huggingface dataset:
Rigid Endoscopic Examination of Neonatal Larynx in OPD as a Screening Procedure
Authors: Pingili Harish Chandra Reddy , Kumar S Ramesh
Published: January 2013

Objectives/hypothesis

To describe a novel method of examination of neonatal larynx, using a 70° rigid 4 mm fiber optic endoscope in OPD as a screening procedure for evaluation of neonatal stridor/hoarse cry.

Study design

Examination technique and safety profile of a novel method of examination of neonatal larynx in OPD using widely available 70° rigid 4 mm endoscope.

Results

Ten neonates, underwent laryngoscopy as described below, whose age and weight in kilograms were recorded. The pulse rate, O2 saturation levels and mean arterial pressure were recorded during the procedure to know the effect of the procedure on hemodynamics and respiration of the neonates. Time taken for the procedure for satisfactory view of larynx is also recorded and tabulated.

Conclusion

The novel method of examination of neonatal larynx using 70° 4 mm rigid endoscope in OPD/ward is a safe procedure and gives excellent view/recording of neonatal larynx in its native anatomical and functional status.

How to cite this article

Pingili HCR, Kumar SR. Rigid Endoscopic Examination of Neonatal Larynx in OPD as a Screening Procedure. Int J Phonosurg Laryngol 2012;2(2): 74-76.
Stridor due to Bilateral Implant Migration 5 Years after Bilateral Medialization Laryngoplasty
Authors: Shukla Sunita Chhapola
Published: January 2013

Implants like silastic, titanium, Gore-Tex and autologous cartilage have been used for type I laryngoplasty. Though rare, implant extrusion or migration, wound infection and airway compromise are some of the complications of medialization laryngoplasty surgery irrespective of the implant used. We document a rare case of bilateral implant migration in a patient who had undergone bilateral medialization laryngoplasty 5 years ago. Gore-Tex extrusion resulted in stridor 5 years after the initial surgery. Endoscopic removal of the extruded implant is advised, if feasible, without the need for tracheostomy or transcervical approach. An update on current knowledge and management of implant extrusion or migration is discussed. How to cite this article: Nerurkar NK, Shukla SC. Stridor due to Bilateral Implant Migration 5 Years after Bilateral Medialization Laryngoplasty. Int J Phonosurg and Laryngol 2012;2(2):82-84.
Technical Note: New methodology for measuring viscosities in small volumes characteristic of environmental chamber particle samples
Authors: Renbaum-Wolff L. , Grayson J. W. , Bertram A. K.
Published: January 2013

Abstract. Herein, a method for the determination of viscosities of small sample volumes is introduced, with important implications for the viscosity determination of particle samples from environmental chambers (used to simulate atmospheric conditions). The amount of sample needed is < 1 μl, and the technique is capable of determining viscosities (η) ranging between 10−3 and 103 Pascal seconds (Pa s) in samples that cover a range of chemical properties and with real-time relative humidity and temperature control; hence, the technique should be well-suited for determining the viscosities, under atmospherically relevant conditions, of particles collected from environmental chambers. In this technique, supermicron particles are first deposited on an inert hydrophobic substrate. Then, insoluble beads (~1 μm in diameter) are embedded in the particles. Next, a flow of gas is introduced over the particles, which generates a shear stress on the particle surfaces. The sample responds to this shear stress by generating internal circulations, which are quantified with an optical microscope by monitoring the movement of the beads. The rate of internal circulation is shown to be a function of particle viscosity but independent of the particle material for a wide range of organic and organic-water samples. A calibration curve is constructed from the experimental data that relates the rate of internal circulation to particle viscosity, and this calibration curve is successfully used to predict viscosities in multicomponent organic mixtures.
Impact of Gobi desert dust on aerosol chemistry of Xi'an, inland China during spring 2009: differences in composition and size distribution between the urban ground surface and the mountain atmosphere
Authors: Wang G. H. , Zhou B. H. , Cheng C. L. , Cao J. J. , Li J. J. , Meng J. J. , Tao J. , Zhang R. J. , Fu P. Q.
Published: January 2013

Abstract. Composition and size distribution of atmospheric aerosols from Xi'an city (~400 m, altitude) in inland China during the spring of 2009 including a massive dust event on 24 April were measured and compared with a parallel measurement at the summit (2060 m, altitude) of Mt. Hua, an alpine site nearby Xi'an. EC (elemental carbon), OC (organic carbon) and major ions in the city were 2–22 times higher than those on the mountaintop during the whole sampling period. Compared to that in the non-dust period a sharp increase in OC was observed at both sites during the dust period, which was mainly caused by an input of biogenic organics from the Gobi desert. However, adsorption/heterogeneous reaction of gaseous organics with dust was another important source of OC in the urban, contributing 22% of OC in the dust event. In contrast to the mountain atmosphere where fine particles were less acidic when dust was present, the urban fine particles became more acidic in the dust event than in the non-dust event, mainly due to enhanced heterogeneous formation of nitrate and diluted NH3. Cl− and NO3− in the urban air during the dust event significantly shifted toward coarse particles. Such redistributions were further pronounced on the mountaintop when dust was present, resulting in both ions almost entirely staying in coarse particles. On the contrary, no significant spatial difference in size distribution of SO42− was found between the urban ground surface and the mountain atmosphere, which dominated in the fine mode (<2.1 μm) during the nonevent and comparably distributed in the fine (<2.1 μm) and coarse (>2.1 μm) modes during the dust event.
Decadal record of satellite carbon monoxide observations
Authors: Worden H. M. , Deeter M. N. , Frankenberg C. , George M. , Nichitiu F. , Worden J. , Aben I. , Bowman K. W. , Clerbaux C. , Coheur P. F. , de Laat A. T. J. , Detweiler R. , Drummond J. R. , Edwards D. P. , Gille J. C. , Hurtmans D. , Luo M. , Martínez-Alonso S. , Massie S. , Pfister G. , Warner J. X.
Published: January 2013

Abstract. Atmospheric carbon monoxide (CO) distributions are controlled by anthropogenic emissions, biomass burning, transport and oxidation by reaction with the hydroxyl radical (OH). Quantifying trends in CO is therefore important for understanding changes related to all of these contributions. Here we present a comprehensive record of satellite observations from 2000 through 2011 of total column CO using the available measurements from nadir-viewing thermal infrared instruments: MOPITT, AIRS, TES and IASI. We examine trends for CO in the Northern and Southern Hemispheres along with regional trends for Eastern China, Eastern USA, Europe and India. We find that all the satellite observations are consistent with a modest decreasing trend ~ −1 % yr−1 in total column CO over the Northern Hemisphere for this time period and a less significant, but still decreasing trend in the Southern Hemisphere. Although decreasing trends in the United States and Europe have been observed from surface CO measurements, we also find a decrease in CO over E. China that, to our knowledge, has not been reported previously. Some of the interannual variability in the observations can be explained by global fire emissions, but the overall decrease needs further study to understand the implications for changes in anthropogenic emissions.
Aerosol decadal trends – Part 2: In-situ aerosol particle number concentrations at GAW and ACTRIS stations
Authors: Asmi A. , Collaud Coen M. , Ogren J. A. , Andrews E. , Sheridan P. , Jefferson A. , Weingartner E. , Baltensperger U. , Bukowiecki N. , Lihavainen H. , Kivekäs N. , Asmi E. , Aalto P. P. , Kulmala M. , Wiedensohler A. , Birmili W. , Hamed A. , O'Dowd C. , G Jennings S. , Weller R. , Flentje H. , Fjaeraa A. M. , Fiebig M. , Myhre C. L. , Hallar A. G. , Swietlicki E. , Kristensson A. , Laj P.
Published: January 2013

Abstract. We have analysed the trends of total aerosol particle number concentrations (N) measured at long-term measurement stations involved either in the Global Atmosphere Watch (GAW) and/or EU infrastructure project ACTRIS. The sites are located in Europe, North America, Antarctica, and on Pacific Ocean islands. The majority of the sites showed clear decreasing trends both in the full-length time series, and in the intra-site comparison period of 2001–2010, especially during the winter months. Several potential driving processes for the observed trends were studied, and even though there are some similarities between N trends and air temperature changes, the most likely cause of many northern hemisphere trends was found to be decreases in the anthropogenic emissions of primary particles, SO2 or some co-emitted species. We could not find a consistent agreement between the trends of N and particle optical properties in the few stations with long time series of all of these properties. The trends of N and the proxies for cloud condensation nuclei (CCN) were generally consistent in the few European stations where the measurements were available. This work provides a useful comparison analysis for modelling studies of trends in aerosol number concentrations.
Automated thunderstorm tracking: utilization of three-dimensional lightning- and radar data
Authors: Meyer V. K. , Höller H. , Betz H. D.
Published: January 2013

Abstract. This paper presents a new hybrid method for automated thunderstorm observation by tracking and monitoring of electrically charged cells (ec-TRAM). The developed algorithm combines information about intense ground precipitation derived from low-level radar-reflectivity scans with three-dimensionally resolved lightning data, which are provided by the European VLF/LF lightning detection network LINET. Based on the already existing automated radar tracker rad-TRAM (Kober and Tafferner, 2009), the new method li-TRAM identifies and tracks electrically active regions in thunderclouds using lightning data only. The algorithm ec-TRAM uses the output of the two autonomously operating routines rad-TRAM and li-TRAM in order to assess, track, and monitor a more comprehensive picture of thunderstorms. The main motivation of this work is to assess the benefit of three-dimensionally resolved total lightning information (TL) for thunderstorm tracking and nowcasting. The focus is laid on the temporal development whereby TL is characterized by an effective in-cloud (IC) and cloud-to-ground (CG) event-discrimination. It is found that the algorithms li-TRAM and ec-TRAM are both feasible methods for thunderstorm nowcasting. The tracking performance of li-TRAM turns out to be comparable to that of rad-TRAM, a result that strongly encourages utilization of lightning data as independent data source for thunderstorm tracking. It is found that lightning data allow an accurate and close monitoring of storm regions with intense internal dynamics as soon as convection induces electrical activity. A case study shows that the current short-term storm dynamics are clearly reflected in the amount of strokes, change of stroke rates and IC/CG ratio. The hybrid method ec-TRAM outperforms rad-TRAM and li-TRAM regarding reliability and continuous assessment of storm tracks especially in more complexly developing storms, where the use of discharge information contributes to more detailed information about storm stage and storm evolution.
The temporal evolution of three-dimensional lightning parameters and their suitability for thunderstorm tracking and nowcasting
Authors: Meyer V. K. , Höller H. , Betz H. D.
Published: January 2013

Abstract. Total lightning (TL) data has been found to provide valuable information about the internal dynamics of a thunderstorm allowing conclusions about its further development as well as indicating potential of thunderstorm-related severe weather at the ground. This paper investigates electrical discharge correlations of strokes and flashes with respect to the temporal evolution of thunderstorms in case studies as well as by statistical means. The recently developed algorithm li-TRAM (tracking and monitoring of lightning-cells, Meyer et al., 2012) has been employed to track and monitor thunderstorms based on three-dimensionally resolved TL lightning data provided as stroke events by the European lightning location network LINET. From statistical investigation of 863 suited thunderstorm life-cycles the cell area turned out to correlate well with (a) the total discharge rate, (b) the in-cloud (IC) discharge rate, and (c) the mean IC discharge height per lightning-cell as identified by li-TRAM. All three parameter correlations consistently show an abrupt change in discharge characteristics around a cell area of 170 km2. Statistical investigations supported by the comparison of three case studies – selected to represent a single storm, a multi-cell and a supercell – strongly suggest that the correlation functions include the temporal evolution as well as the storm type. With the help of volumetric radar data, it can also be suggested that the well defined break observed at 170 km2 marks the region, where the transition occurs from short-lived and rather simple structured single storm cells to better organized, more persistent, and more complex structured thunderstorm forms, e.g. multi-cells and super-cells. All three storm-types experience similar discharge characteristics during their growing and dissipating phases. However, while the poorly organized and short-lived cells preferentially remain small during a short mature phase, mainly the more persistent thunderstorm types develop to sizes above 170 km2 during a pronounced mature stage. At that stage they exhibit on average higher discharge rates at higher altitudes as compared with matured single-cells. With the maximum stroke distance set to 10 km and a flash duration set to 1 s the parameterisation functions found for the stroke rate as function of the cell area has been transformed to a flash rate. The presented study suggests that, with respect to the storm type, stroke and flash correlations can be parameterized. There is also strong evidence, that parameterization functions include the time parameter, so that altogether TL stroke information has good potential to pre-estimate the further evolution (nowcast) of a currently observed storm in an object-oriented thunderstorm nowcasting approach.
Total sulphate vs. sulphuric acid monomer in nucleation studies: which represents the "true" concentration?
Authors: Neitola K. , Brus D. , Makkonen U. , Sipilä M. , Mauldin III R. L. , Kyllönen K. , Lihavainen H. , Kulmala M.
Published: January 2013

Abstract. Sulphuric acid is known to be a key component for atmospheric nucleation. Precise determination of sulphuric acid concentration is crucial factor for prediction of nucleation rates and subsequent growth. In our study, we have noticed a substantial discrepancy between sulphuric acid monomer and total sulphate concentrations measured from the same source of sulphuric acid vapour. The discrepancy of about one to two orders of magnitude was found with similar formation rates. The reason for this difference is not yet clear and it can have great impact on predicting atmospheric nucleation rates as well as growth rates. To investigate this discrepancy and its effect on nucleation, a method of thermally controlled saturator filled with pure sulphuric acid (~97%) for production of sulphuric acid vapour is introduced and tested. Sulphuric acid-water nucleation experiment was done using a laminar flow tube. Two independent methods of mass spectrometry and online ion chromatography were used for detecting sulphuric acid concentrations. The results are compared to our previous results, where a method of evaporating weak sulphuric acid-water solution droplets in a furnace was used to produce sulphuric acid vapour (Brus et al., 2010, 2011). Measured sulphuric acid concentrations are compared to theoretical prediction calculated using vapour pressure and simple mixing law. The calculated prediction of sulphuric acid concentrations agrees very well with the measured values when total sulphate is considered. Sulphuric acid monomer concentration was found to be about two orders of magnitude lower than the prediction, but with similar temperature dependency as the prediction and the results obtained with ion chromatograph method. Formation rates agree well when compared to our previous results with both sulphuric acid detection and sulphuric acid production methods separately.
Aerosol extinction to backscatter ratio derived from passive satellite measurements
Authors: Bréon F.-M.
Published: January 2013

Abstract. Spaceborne reflectance measurements from the POLDER instrument are used to study the specific directional signature close to the backscatter direction. The data analysis makes it possible to derive the extinction to backscatter ratio (EBR) which is the invert of the scattering phase function for an angle of 180° and is needed for a quantitative interpretation of lidar observations (active measurements). In addition, the multi-directional measurements are used to quantify the scattering phase function variations close to backscatter, which also provide some indication of the aerosol particle size and shape. The spatial distributions of both parameters show consistent patterns that are consistent with the aerosol type distributions. Pollution aerosols have an EBR close to 70, desert dust values are on the order of 50, while marine aerosol's is close to 25. The scattering phase function shows an increase with the scattering angle close to backscatter. The relative increase ∂lnP/∂ γ is close to 0.01 for dust and pollution type aerosols and 0.06 for marine type aerosols. These values are consistent with those retrieved from Mie simulations.
Isotope- and tracer-based measurements of fossil fuel and biospheric carbon dioxide in Paris during winter 2010
Authors: Lopez M. , Schmidt M. , Delmotte M. , Colomb A. , Gros V. , Janssen C. , Lehman S. J. , Mondelain D. , Perrussel O. , Ramonet M. , Xueref-Remy I. , Bousquet P.
Published: January 2013

Abstract. Measurements of the mole fraction of the CO2 and its isotopes were performed in Paris during the MEGAPOLI winter campaign (January–February 2010). Radiocarbon (14CO2) measurements were used to identify the relative contributions of 77% CO2 from fossil fuel consumption (CO2ff from liquid and gas combustion) and 23% from biospheric CO2 (CO2 from the use of biofuels and from human and plant respiration: CO2bio). These percentages correspond to average mole fractions of 26.4 ppm and 8.2 ppm for CO2ff and CO2bio, respectively. The 13CO2 analysis indicated that gas and liquid fuel contributed 70% and 30%, respectively, of the CO2 emission from fossil fuel use. Continuous measurements of CO and NOx and the ratios CO/CO2ff and NOx/CO2ff derived from radiocarbon measurements during four days make it possible to estimate the fossil fuel CO2 contribution over the entire campaign. The ratios CO/CO2ff and NOx/CO2ff are functions of air mass origin and exhibited daily ranges of 7.9 to 14.5 ppb ppm−1 and 1.1 to 4.3 ppb ppm−1, respectively. These ratios are sufficiently consistent with different emission inventories given the uncertainties of the different approaches.
A simplified approach for generating GNSS radio occultation refractivity climatologies
Authors: Gleisner H. , Healy S. B.
Published: January 2013

Abstract. The possibility of simplifying the retrieval scheme required to produce GNSS radio occultation refractivity climatologies is investigated. In a new, simplified retrieval approach, the main statistical analysis is performed in bending angle space and an estimate of the average bending angle profile is then propagated through an Abel transform. The average is composed of means and medians of ionospheric corrected bending angles up to 80 km. Above that, the observed profile is exponentially extrapolated to infinity using a fixed a priori scale height. The new approach circumvents the need to introduce a "statistical optimisation" processing step in which individual bending angle profiles are merged with a priori data, often taken from a climatology. This processing step can be complex, difficult to interpret, and is generally recognised as a potential source of structural uncertainty. The new scheme is compared with the more conventional approach of averaging individual refractivity profiles, produced with the implementation of statistical optimisation used in the EUMETSAT Radio Occultation Meteorology Satellite Application Facility (ROM SAF) operational processing. It is shown that the two GNSS radio occultation climatologies agree to within 0.1% from 5 km up to 35–40 km, for the three months January, February, and March 2011. During this time period, the new approach also produces slightly better agreement with ECMWF analyses between 40–50 km, which is encouraging. The possible limitations of the new approach caused by mean residual ionospheric errors and low observation numbers are discussed briefly, and areas for future work are suggested.
A non-iterative linear retrieval for infrared high resolution limb sounders
Authors: Millán L. , Dudhia A.
Published: January 2013

Abstract. Currently most of the high spectral resolution infrared limb sounders use subsets of the recorded spectra (microwindows) in their retrieval schemes to reduce the computing time of rerunning the radiative transfer model. A fast linear retrieval scheme is described which allows the whole spectral signature of the target molecule to be used. We determine how close the linearisation point needs to be to the solution in order to fall in the linear regime and also suggest an adjustment to the forward model and Jacobians to propagate the change in pressure and temperature on the gas concentration retrievals. As an example, this technique is implemented for the Michelson Interferometer for Passive Atmospheric Sounding instrument, but it is applicable to any high resolution limb sounder.
Column water vapor determination in night period with a lunar photometer prototype
Authors: Barreto A. , Cuevas E. , Damiri B. , Romero P. M. , Almansa F.
Published: January 2013

Abstract. In this paper we present the preliminary results of atmospheric column integrated water vapor (PWV) obtained with a new Lunar Cimel photometer (LC) at the high mountain Izaña Observatory in the period July–August, 2011. We have compared nocturnal PWV from LC with PWV from a Global Positioning System (GPS) receiver and nighttime radiosondes (RS92). LC data have been calibrated using the Lunar Langley Method (LLM). We complemented this comparative study using quasi-simultaneous daytime PWV from Cimel AERONET (CA), GPS and RS92. Comparison of daytime PWV from CA shows differences against GPS and RS92 up to 0.18 cm. Two different filters, with and approximate bandwidth of 10 nm and central wavelengths at 938 nm (Filter#1) and 937 nm (Filter#2), were mounted into the LC. Filter#1 is currently used in operational AERONET sunphotometers. PWV obtained with LC-Filter#1 showed an overestimation above 0.18 and 0.25 cm compared to GPS and RS92, respectively, meanwhile Filter#2, with a reduced out-of-band radiation, showed very low differences compared with the same references (≤0.03 cm). These results demonstrate the ability of the new lunar photometer to obtain accurate and continuous PWV measurements at night in addition to the notably influence of the filter's transmissivity response on PWV determination at nighttime. The use of enhanced bandpass filters in lunar photometry, which is affected by more important inaccuracies than sun-photometry, is necessary to infer PWV with similar precision than AERONET.
The Gela Basin pockmark field in the strait of Sicily (Mediterranean Sea): chemosymbiotic faunal and carbonate signatures of postglacial to modern cold seepage
Authors: Taviani M. , Angeletti L. , Ceregato A. , Foglini F. , Froglia C. , Trincardi F.
Published: January 2013

Abstract. The geo-biological exploration of a pockmark field located at ca. −800 m in the Gela basin (Strait of Sicily, Central Mediterranean) provided a relatively diverse chemosymbiotic community and methane-imprinted carbonates. To date, this is the first occurrence of such type of specialized deep-water cold-seep communities recorded from this key region, before documented in the Mediterranean as rather disjunct findings in its eastern and westernmost basins. The thiotrophic chemosymbiotic organisms recovered from this area include empty tubes of the vestimentiferan Lamellibrachia sp., loose and articulated shells of lucinids (Lucinoma kazani, Myrtea amorpha), vesicomyids (Isorropodon perplexum), and gastropods (Taranis moerchi). A callianassid decapod (Calliax sp.) was consistently found alive in large numbers in the pockmark mud. Their post-mortem calcified parts mixed with molluscs and subordinately miliolid foraminifers form a distinct type of skeletal assemblage (named DECAMOL). Carbonate concretions display δ13C values as low as −40 ‰ PDB suggesting the occurrence of light hydrocarbons in the seeping fluids. Since none of the truly chemosymbiotic organisms was found alive, although their skeletal parts appear at times very fresh, some specimens have been AMS-14C dated to shed light on the historical evolution of this site. Lamellibrachia and Lucinoma are two of the most significant chemosymbiotic taxa reported from various Mediterranean cold seep sites (Alboran Sea and Eastern basin). Specimens from station MEDCOR78 (pockmark#1, Lat 36°46´10.18´´ N, Long 14°01´31.59´´ E, −815 m) provided ages of 11 736 ± 636 yr cal BP (Lamellibrachia sp.), and 9609.5 ± 153.5 yr cal BP (L. kazani). One shell of M. amorpha in core MEDCOR81 (pockmark#6, Lat 36°45´38.89´´ N, Long 14°00´07.58´´ E, −822 m) provided a sub-modern age of 484 ± 54 yr cal BP. These ages document that fluid seepage at this pockmark site has been episodically sustaining thiotrophic macrobenthic communities since the end of the Younger Dryas stadial up to sub-recent times.
Stable isotopes in caves over altitudinal gradients: fractionation behaviour and inferences for speleothem sensitivity to climate change
Authors: Johnston V. E. , Borsato A. , Spötl C. , Frisia S. , Miorandi R.
Published: January 2013

Abstract. The interpretation of stable isotope ratios in speleothem calcite is complex, and only in a few cases, unequivocal relationships with palaeoclimate parameters have been attained. A major issue is temperature, which has an effect on both the isotope incorporation into calcite and on environmental processes. Here, a field approach is taken, by studying the isotopic composition of calcites from monitored caves located in steep altitudinal topography in the northern Italian Alps. These create a thermal gradient (3–12 °C) apt to study the effects of temperature on the speleothem isotope record. Our data indicate that the magnitude of oxygen isotope disequilibrium effects, calculated as an offset from the experimentally determined equilibrium, decreases with increased elevation (cooler temperatures) and faster drip rate. Carbon isotope values exhibit 13C enrichment at high altitudes (colder temperatures) and slow drip rates. The results obtained support modelling and laboratory cave analogue experiments that indicate temperature, drip rate, pCO2 and supersaturation are important factors controlling stable isotope fractionation, but also stress the significance of ventilation and evaporation in the cave environment. It is proposed that the effects on stable isotope ratios observed along the altitudinal gradient can be analogues for glacial to interglacial temperature changes in regions which were extensively glaciated in the past.
Calibration of the Crop model in the Community Land Model
Authors: Zeng X. , Drewniak B. A. , Constantinescu E. M.
Published: January 2013

Abstract. Farming is using more terrestrial ground with increases in population and the expanding use of agriculture for non-nutritional purposes such as biofuel production. This agricultural expansion exerts an increasing impact on the terrestrial carbon cycle. In order to understand the impact of such processes, the Community Land Model (CLM) has been augmented with a CLM-Crop extension that simulates the development of three crop types: maize, soybean, and spring wheat. The CLM-Crop model is a complex system that relies on a suite of parametric inputs that govern plant growth under a given atmospheric forcing and available resources. CLM-Crop development used measurements of gross primary productivity and net ecosystem exchange from AmeriFlux sites to choose parameter values that optimize crop productivity in the model. In this paper we calibrate these values in order to provide a faithful projection in terms of both plant development and net carbon exchange, using a Markov chain Monte Carlo technique.
A semi-implicit, second order accurate numerical model for multiphase underexpanded volcanic jets
Authors: Carcano S. , Bonaventura L. , Esposti Ongaro T. , Neri A.
Published: January 2013

Abstract. An improved version of the PDAC (Pyroclastic Dispersal Analysis Code, Esposti Ongaro et al., 2007) numerical model for the simulation of multiphase volcanic flows is presented and validated for the simulation of multiphase volcanic jets in supersonic regimes. The present version of PDAC includes second-order time and space discretizations and fully multidimensional advection discretizations, in order to reduce numerical diffusion and enhance the accuracy of the original model. The model is tested on the problem of jet decompression, in both two and three dimensions. For homogeneous jets, numerical results are consistent with experimental results at the laboratory scale (Lewis and Carlson, 1964). For non-equilibrium gas-particle jets, we consider monodisperse and bidisperse mixtures and we quantify non-equilibrium effects in terms of the ratio between the particle relaxation time and a characteristic jet time scale. For coarse particles and low particle load, numerical simulations well reproduce laboratory experiments and numerical simulations carried out with an Eulerian-Lagrangian model (Sommerfeld, 1993). At the volcanic scale, we consider steady-state conditions associated to the development of Vulcanian and sub-Plinian eruptions. For the finest particles produced in these regimes, we demonstrate that the solid phase is in mechanical and thermal equilibrium with the gas phase and that the jet decompression structure is well described by a pseudogas model (Ogden et al., 2008). Coarse particles, on the contrary, display significant non-equilibrium effects, associated to their larger relaxation time. Deviations from the equilibrium regime occur especially during the rapid acceleration phases and are able to appreciably modify the average jet dynamics, with maximum velocity and temperature differences of the order of 150 m s−1 and 80 K across shock waves.
A model based on dimensional analysis for prediction of nitrogen and phosphorus concentrations at the river station Ižkovce, Slovakia
Authors: Zeleňáková M. , Čarnogurská M. , Šlezingr M. , Słyś D. , Purcz P.
Published: January 2013

Abstract. The aim of this paper is to develop a model for pollutant concentration prediction in a stream. The developed model that determines nitrogen and phosphorus concentrations in a river is based on a dimensional analysis. Application of dimensional analysis to water quality modelling is presented, pointing out possibilities of applying this methodology in water quality research. We investigate how dimensional analysis can be applied to water quality modelling and which benefits it can bring to researchers in this area. For modelling water quality in a water stream it is essential to know the parameters that influence water quality. The relevant parameters are flow of water in the river (discharge), its catchment area, velocity of water in the stream, temperature of water, temperature of air and measured concentrations of the pollutant – nitrogen and phosphorus. A sensitivity analysis shows that the concentration of pollutant in water stream is sensitive to changes in both water and air temperatures. The model performs well when average values are used; the prediction error increases when the single concentration values are considered. The model was developed, calibrated and evaluated using measured data from the river station Ižkovce, River Laborec in eastern Slovakia.
Streamflow response of a small forested catchment on different timescales
Authors: Zabaleta A. , Antigüedad I.
Published: January 2013

Abstract. The hydrological response of a catchment to rainfall on different timescales is result of a complex system involving a range of physical processes which may operate simultaneously and have different spatial and temporal influences. This paper presents the analysis of streamflow response of a small humid-temperate catchment (Aixola, 4.8 km2) in the Basque Country on different timescales and discusses the role of the controlling factors. Firstly, daily time series analysis was used to establish a hypothesis on the general functioning of the catchment through the relationship between precipitation and discharge on an annual and multiannual scale (2003–2008). Second, rainfall-runoff relationships and relationships among several hydrological variables, including catchment antecedent conditions, were explored at the event scale (222 events) to check and improve the hypothesis. Finally, the evolution of electrical conductivity (EC) during some of the monitored storm events (28 events) was examined to identify the time origin of waters. Quick response of the catchment to almost all the rainfall events as well as a considerable regulation capacity was deduced from the correlation and spectral analyses. These results agree with runoff event scale data analysis; however, the event analysis revealed the non-linearity of the system, as antecedent conditions play a significant role in this catchment. Further, analysis at the event scale made possible to clarify factors controlling (precipitation, precipitation intensity and initial discharge) the different aspects of the runoff response (runoff coefficient and discharge increase) for this catchment. Finally, the evolution of EC of the waters enabled the time origin (event or pre-event waters) of the quickflow to be established; specifically, the conductivity showed that pre-event waters usually represent a high percentage of the total discharge during runoff peaks. The importance of soil waters in the catchment is being studied more deeply.
Thermodynamics, maximum power, and the dynamics of preferential river flow structures at the continental scale
Authors: Kleidon A. , Zehe E. , Ehret U. , Scherer U.
Published: January 2013

Abstract. The organization of drainage basins shows some reproducible phenomena, as exemplified by self-similar fractal river network structures and typical scaling laws, and these have been related to energetic optimization principles, such as minimization of stream power, minimum energy expenditure or maximum "access". Here we describe the organization and dynamics of drainage systems using thermodynamics, focusing on the generation, dissipation and transfer of free energy associated with river flow and sediment transport. We argue that the organization of drainage basins reflects the fundamental tendency of natural systems to deplete driving gradients as fast as possible through the maximization of free energy generation, thereby accelerating the dynamics of the system. This effectively results in the maximization of sediment export to deplete topographic gradients as fast as possible and potentially involves large-scale feedbacks to continental uplift. We illustrate this thermodynamic description with a set of three highly simplified models related to water and sediment flow and describe the mechanisms and feedbacks involved in the evolution and dynamics of the associated structures. We close by discussing how this thermodynamic perspective is consistent with previous approaches and the implications that such a thermodynamic description has for the understanding and prediction of sub-grid scale organization of drainage systems and preferential flow structures in general.
Training hydrologists to be ecohydrologists: a "how-you-can-do-it" example leveraging an active learning environment for studying plant–water interaction
Authors: Lyon S. W. , Walter M. T. , Jantze E. J. , Archibald J. A.
Published: January 2013

Abstract. Structuring an education strategy capable of addressing the various spheres of ecohydrology is difficult due to the inter-disciplinary and cross-disciplinary nature and general breadth of this emergent field. Clearly, there is a need for such strategies to accommodate more progressive educational concepts while highlighting a skills-based education. To demonstrate a possible way to develop courses that include such concepts, we offer a case-study or a potential "how-you-can-do-it" example from a recent course set in an ecohydrological context co-taught by teachers from Stockholm University and Cornell University at Stockholm University's Navarino Environmental Observatory (NEO) in Costa Navarino, Greece. This course focused on introducing hydrology Master's students to some of the central concepts of ecohydrology, while at the same time supplying process-based understanding relevant for characterizing evapotranspiration. As such, the main goal of the course was to explore some of the central theories in ecohydrology and their connection to plant–water interactions and the water cycle in a semiarid environment. While this course is still in its infancy with regards to addressing some of the more in-depth aspects of ecohydrology, it does provide a relevant basis with an initial emphasis on the more physical concepts of ecohydrology from which to build towards the more physiological concepts (e.g., unique plant adaptations to water availability or differences in water use between native plants and irrigated vegetation). In addition to presenting this roadmap for ecohydrology course development, we explore the utility and effectiveness of adopting active teaching and learning strategies drawing from the suite of learn-by-doing, hands-on, and inquiry-based techniques in such a course. We test a potential gradient of "activeness" across a sequence of three teaching and learning activities. Our results indicate that there was a clear advantage for utilizing active learning with a preference among the students towards the more "active" techniques. This demonstrates the added value of incorporating even the simplest active learning approaches in our ecohydrology (or general) teaching.
The effect of watershed scale on HEC-HMS calibrated parameters: a case study in the Clear Creek watershed in Iowa, USA
Authors: Zhang H. L. , Wang Y. J. , Wang Y. Q. , Li D. X. , Wang X. K.
Published: January 2013

Abstract. In this paper, we use the Hydrologic Modeling System (HEC-HMS) to simulate two flood events to investigate the effect of watershed subdivision in terms of performance, the calibrated parameter values, the description of hydrologic processes, and the subsequent interpretation of water balance components. We use Stage-IV hourly NEXRAD precipitation as the meteorological input for ten model configurations with variable sub-basin sizes. Model parameters are automatically optimized to fit the observed data. The strategy is implemented in Clear Creek Watershed (CCW), which is located in the upper Mississippi River basin. Results show that most of the calibrated parameter values are sensitive to the basin partition scheme and that the relative relevance of physical processes, described by the model, change depending on watershed subdivision. In particular, our results show that parameters derived from different model implementations attribute losses in the system to completely different physical phenomena without a notable effect on the model's performance. Our work adds to the body of evidence demonstrating that automatically calibrated parameters in hydrological models can lead to an incorrect prescription of the internal dynamics of runoff production and transport. Furthermore, it demonstrates that model implementation adds a new dimension to the problem of non-uniqueness in hydrological models.
Implantation of Resorbable Gentamicin Sponges in Addition to Irrigation and Debridement in 34 Patients with Infection Complicating Total Hip Arthroplasty
Authors: Kuiper Jesse W.P. , Brohet Richard M. , Wassink Sander , van den Bekerom Michel P.J. , Nolte Petrus A. , Vergroesen Diederik A.
Published: January 2013

We evaluated a prosthesis-retaining treatment protocol for prosthetic joint infection in patients presenting at a mean of 116 days (range 10-1216 days) after primary arthroplasty. Our regime involved irrigation and debridement followed by implantation of biodegradable gentamicin loaded sponges which do not require removal after implantation.

Of 34 patients with a deep infection after total hip arthroplasty, Twenty-five were treated successfully, with a mean follow-up of 35 months. There were no permanent complications. This success rate is comparable to earlier studies. Early initiation of treatment demonstrated a tendency for better results, and late chronic infections had a worse outcome. Because the sponges are degradable, a number of further surgical procedures were avoided.
The Analgesic Impact of Preoperative Lumbar Plexus Blocks for Hip Arthroscopy. A Retrospective Review
Authors: Schroeder Kristopher M. , Donnelly Melanie J. , Anderson Brooke M. , Ford Michael P. , Keene James S.
Published: January 2013

This study aimed to examine the impact of preoperative lumbar plexus blockade on perioperative analgesia and opioid consumption following hip arthroscopy. The records of patients (n = 236) who underwent hip arthroscopy between July 27, 2004 and November 15, 2009 were reviewed (118 patients with preoperative lumbar plexus block and 118 procedure matched patients without a preoperative block). Baseline patient characteristics were similar between groups. Immediate post-anaesthesia care unit (PACU) pain scores, peak PACU pain scores, perioperative opioid administration, and PACU antiemetic administration favoured preoperative block placement. Postoperative modified Harris Hip scores and postoperative day one pain scores were similar between groups. Total hospital time following the surgical procedure was longer in the block group. While preoperative lumbar plexus blockade may be helpful for analgesia following hip arthroscopy, more research needs to be done to determine the ideal analgesic regimen for these patients.
Riparazione Laparoscopica di Fistola Enterovescicale in Paziente Portatore di Megauretere sx
Authors: Parma Paolo , Samuelli Alessandro , Dall'Oglio Bruno
Published: January 2013

Introduction

Enterovesical fistula (EVF) is an abnormal communication between the intestine and the bladder. We present the case of EVF secondary to diverticular disease in a male with congenital megaureter. A laparoscopic repair of the colon vesical fistula was performed with colon resection.

Materials and Methods

With the patient in the Trendelenburg position −30° degrees on the right side, 5 trocars are positioned trans-peritoneally. The exploration of the abdominal cavity shows the sigmoid diverticular disease adhering tenaciously to the posterior wall of the bladder. The intestinal loops are medialized. The inferior mesenteric vein is isolated, clipped and divided. The mesosigma is isolated and the inferior mesenteric artery is closed 2 cm from its emergence from the aorta with EndoGIA™ 45 stapler. The left colon is isolated from its splenic flexure to the mesorectum. The peritoneum between the bladder and sigmoid colon at the site of the tenacious adhesions is incised. The left megaureter is isolated from the diverticular disease and the bladder is opened on the site of the fistula, to permit a wide resection of the fistula. The posterior wall of the bladder is then closed with double running sutures. Section of the rectum with EndoGIA™ 45 stapler. Extraction of 20 cm of sigma comprising diverticular disease by a 5 cm suprapubic laparotomy. The sigma is cut and the proximal head of the circular stapler is inserted and closed with a running suture. The left colon is put back in place into the peritoneal cavity. The laparotomy is closed and the surgery is reconverted into laparoscopy. A colorectal end-to-end anastomosis according to Knight Griffen is performed with ILS 29 circular stapler. The anastomosis is tested for leakage with hydropneumatic test: no evidence of spillage. A laminar drainage is placed close to the anastomosis and the incisions are closed.

Results

The operative time was 240 minutes. There were no intra- or post-operative complications. The bladder catheter was removed on day 7 after cystography. The patient was discharged asymptomatic on the 8th post-operative day.

Conclusions

Laparoscopic treatment of enterovesical fistulas for benign disease is a safe and standardized procedure. It remains a difficult procedure with a conversion rate higher than laparoscopy for uncomplicated diverticulitis or malignancy. The procedure in a single session with intracorporeal bowel anastomosis is the standard.
The Use of Postoperative Restraints in Children after Cleft Lip or Cleft Palate Repair: A Preliminary Report
Authors: Huth Jennifer , Petersen J. Dayne , Lehman James A.
Published: January 2013

Purpose. This study examines whether the use of elbow restraints after cleft lip/palate repair has a relationship to postoperative complications. Methods. A comparative descriptive design was used to study a convenience sample of children undergoing repair of cleft lip/palate at Akron Children’s Hospital with Institutional Review Board approval. The children were randomized into intervention or control groups with use of elbow restraints considered the intervention. The study consists of two arms; one examined children after cleft lip repair, the second examined children after cleft palate repair. Repairs were performed by a single surgeon. Data collected included age, comorbidities, patient discomfort measured by pain score, frequency and duration of pain medications, use of pacifier or finger/thumb sucking, and postoperative complications including disruption of the suture line. Results. With 47 post palate repair patients and 47 post cleft repair patients, there is no significant difference () in the occurrence of postoperative complications. Conclusions. Study results provide prospective evidence to support postoperative observation of children by surgery staff and family following cleft lip or cleft palate repair without the use of elbow restraints. Clinicians should reevaluate the use of elbow restraints after cleft lip/palate repair based on the belief restraints prevent postoperative complications.
The role of culture in quality improvement in the intensive care unit: A literature review
Authors: Soh Kim Lam , Soh Kim Geok , Davidson Patricia M
Published: January 2013

Improving the quality of patient care and patient outcomes is a major concern internationally.  In a developing health care system, implementing quality improvement is challenging due not only to resource and workforce issues but also cultural factors.  Using the method of a focussed literature review, this paper discusses the importance of assessing a societal view of culture, social mores and customs, and power relationships in quality improvement activities using the intensive care unit as an exemplar.   We conclude that implementing quality improvement strategies in a developing health care system needs to address the broader perspectives of social and cultural systems particularly hierarchical relationships and issues of non-disclosure.