bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of aging mechanism on model simulated carbonaceous aerosols
Authors: Huang Y. , Wu S. , Dubey M. K. , French N. H. F.
Published: July 2013

Abstract. Carbonaceous aerosols including organic carbon and black carbon have significant implications for both climate and air quality. In the current global climate or chemical transport models, a fixed hydrophobic-to-hydrophilic conversion lifetime for carbonaceous aerosol (τ) is generally assumed, which is usually around one day. We have implemented a new detailed aging scheme for carbonaceous aerosols in a chemical transport model (GEOS-Chem) to account for both the chemical oxidation and the physical condensation-coagulation effects, where τ is affected by local atmospheric environment including atmospheric concentrations of water vapor, ozone, hydroxyl radical and sulfuric acid. The updated τ exhibits large spatial and temporal variations with the global average (up to 11 km altitude) calculated to be 2.6 days. The chemical aging effects are found to be strongest over the tropical regions driven by the low ozone concentrations and high humidity there. The τ resulted from chemical aging generally decreases with altitude due to increases in ozone concentration and decreases in humidity. The condensation-coagulation effects are found to be most important for the high-latitude areas, in particular the polar regions, where the τ values are calculated to be up to 15 days. When both the chemical aging and condensation-coagulation effects are considered, the total atmospheric burdens and global average lifetimes of BC, black carbon, (OC, organic carbon) are calculated to increase by 9% (3%) compared to the control simulation, with considerable enhancements of BC and OC concentrations in the Southern Hemisphere. Model evaluations against data from multiple datasets show that the updated aging scheme improves model simulations of carbonaceous aerosols for some regions, especially for the remote areas in the Northern Hemisphere. The improvement helps explain the persistent low model bias for carbonaceous aerosols in the Northern Hemisphere reported in literature. Further model sensitivity simulations focusing on the continental outflow of carbonaceous aerosols demonstrate that previous studies using the old aging scheme could have significantly underestimated the intercontinental transport of carbonaceous aerosols.
Characterization of light-absorbing carbon particles at three altitudes in East Asian outflow by transmission electron microscopy
Authors: Zhu J. , Crozier P. A. , Anderson J. R.
Published: July 2013

Abstract. The morphology, microstructure, and composition of the submicron fraction of individual light-absorbing carbon (LAC) particles collected by research aircraft during the ACE-Asia (Asian Pacific Regional Aerosol Characterization Experiment) project above the Yellow Sea at altitudes of 120, 450 and 1500 m are investigated by transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). Two types of carbonaceous particles, small spherule soot with graphitic spherules and amorphous carbonaceous spheres (brown carbon), are found at all altitudes in high concentration. For soot particles, emphasis of the study is on the component subparticles (spherules). The nanoscopic structures of the small spherule soot show no significant difference at three altitudes although the size distribution of primary spherules showed that 70% of the total volume lies in the ranges 30–50, 50–85 and 30–50 nm, respectively. For the amorphous carbonaceous spheres, 70% of the total volume from three altitudes lies in the range 200–350, 160–470 and 150–320 nm, respectively. Within the size fraction studied (submicron, with most particles in the range 50 to 500 nm) the number concentration ratios of the amorphous carbonaceous spheres to primary spherules in soot at altitudes of 120, 450 and 1500 m are about 1, 1.5 and 10, respectively and their volume ratios are about 260, 50 and 1400. Lower relative concentrations of large spherule soot with intermediate graphitic structure were observed at 120 m. Also, low relative number concentrations of carbon cenospheres were observed at 120 and 1500 m. A key result of the study is that in vertically stratified outflow from East Asia, the character of LAC may have strong variance with altitude thus resulting in optical characteristics that vary with altitude. Also, apparent "aging" of LAC deduced from samples at multiple ground stations may instead reflect differences in the original carbon aerosols.
Modeling polarized solar radiation from ocean–atmosphere system for CLARREO inter-calibration applications
Authors: Sun W. , Lukashin C.
Published: July 2013

Abstract. Reflected solar radiance from the Earth–atmosphere system is polarized. Radiance measurements can be affected by the reflected light's state of polarization if the radiometric sensor is sensitive to the polarization of observed light. To enable the Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission for inter-calibration of the polarization-sensitive imagers, such as the MODIS, the polarization state of the reflected solar light must be known with sufficient accuracy. For this purpose, the polarized solar radiation from the ocean–atmosphere system is studied with an adding-doubling radiative transfer model (ADRTM). The Cox-and-Munk ocean wave slope distribution model is used in calculation of the reflection matrix of a wind-ruffled ocean surface. An empirical foam spectral reflectance model and an empirical spectral reflectance model for water volume below the surface are integrated in the ocean surface model. Solar reflectance from the ADRTM is compared with that from the discrete-ordinate radiative transfer (DISORT) model. Sensitivity studies for reflected solar radiation are conducted for various ocean-surface and atmospheric conditions for the stratification of polarization distribution models (PDMs), which are to be used in the inter-calibration of the polarization-sensitive imager measurements with the CLARREO data. This modeling provides a reliable approach for making the spectral CLARREO PDMs over the broad solar spectra, which cannot be achieved by empirical PDMs based on the analysis of the data from polarimetric sensors.
The metastable HCl · 6H2O phase – IR spectroscopy, phase transitions and kinetic/thermodynamic properties in the range 170–205 K
Authors: Chiesa S. , Rossi M. J.
Published: July 2013

Abstract. In this laboratory study, 1 to 2 μm thick polycrystalline ice films have been grown under stirred flow reactor (SFR) conditions and subsequently doped with metered amounts of HCl under static conditions. A multidiagnostic approach including FTIR absorption spectroscopy in transmission, residual gas mass spectrometry (MS) and total pressure measurement was employed. Depending on the growth protocol controlling both temperature and partial pressure of HCl (PHCl), either amorphous HCl/H2O or crystalline HCl hexahydrate (HCl · 6H2O) have been obtained. After controlled doping with HCl and evaporation of excess H2O from the ice film, transmission FTIR of pure HCl · 6H2O films and use of calibrated residual gas MS enabled the measurement of differential (peak) IR cross sections at several mid-IR frequencies (σ = (6.5 ± 1.9) × 10-19 cm2 molec-1 at 1635 cm-1 as an example). Two types of kinetic experiments on pure HCl · 6H2O have been performed under SFR conditions: (a) evaporation of HCl · 6H2O under H2O-poor conditions over a narrow T range, and (b) observation of the phase transition from crystalline HCl · 6H2O to amorphous HCl/H2O under H2O-rich conditions at increasing T. The temperature dependence of the zero-order evaporation flux of HCl in pure HCl · 6H2O monitored at 3426 cm-1 led to log(Jev) molec cm-2s-1= (36.34 ± 3.20) - (80 810 ± 5800)/2.303RT with R=8.312 JK−1 mol-1. HCl · 6H2O has a significant intrinsic kinetic barrier to HCl evaporation of 15.1 kJ mol-1 in excess of the HCl sublimation enthalpy of 65.8 kJ mol-1 at 200 K but is kinetically unstable (metastable) at typical UT/LS conditions of HCl partial pressure (P(HCl)) and temperature. Water-rich HCl · 6H2O undergoes a facile phase transition from crystalline to the amorphous/ supercooled/disordered state easily observable at T≥ 195 K under both static and SFR conditions. This corresponds to low P(HCl) in the neighborhood of 10-7 Torr that also prevails at the Upper Troposphere/Lower Stratosphere (UT/LS). The atmospheric importance of HCl · 6H2O is questioned in view of its nucleation barrier and its dependence on temperature and P(HCl) compared to the amorphous HCl/H2O phase.
Modeling of temperature scenarios in a multicore processor system
Authors: Glocker E. , Schmitt-Landsiedel D.
Published: July 2013

Abstract. In modern CMOS integrated Systems-on-Chip global temperature variations arise as well as local fluctuations in regions of high activity, resulting in the arise of local hot spots. This in turn can greatly affect reliability and life-time of a chip. Economically affordable processor packaging cannot be provided for the worst case hot spot scenario. In a multicore system a reciprocal influence between the temperatures of neighbouring cores occur leading to increasing core temperature compared to a single core. This results in the need to monitor and regulate the operating temperature during runtime in order to keep it at tolerable values. This can be done in an easy way in an invasive architecture. In this paper the temperature distributions of cores in a multicore system are simulated for various scenarios. Different task allocation techniques and application characteristics as well as different physical conditions such as package types, material parameters and cooling all result in different system power scenarios. The impact of different scenarios which affect the system temperature scenario is investigated. The results are analysed and compared to determine the worst case scenario. With regard to simulation results and practicability the best temperature levelling measures are chosen.
Implementation of a digital trim scheme for SAR ADCs
Authors: Bialek J. , Wickmann A. , Ohnhaeuser F. , Fischer G. , Weigel R. , Ussmueller T.
Published: July 2013

Abstract. Successive approximation register (SAR) analog-to-digital Converters (ADC) are based on a capacitive digital-to-analog converter (CDAC) (McCreary and Gray, 1975). The capacitor mismatch in the capacitor array of the CDAC impacts the differential non-linearity (DNL) of the ADC directly. In order to achieve a transfer function without missing codes, trimming of the capacitor array becomes necessary for SAR ADCs with a resolution of more than 12 bit. This article introduces a novel digital approach for trimming. DNL measurements of an 18 bit SAR ADC show that digital trimming allows the same performance as analog trimming. Digital trimming however reduces the power consumption of the ADC, the die size and the required time for the production test.
Dead time optimization method for power converter
Authors: Deselaers C. , Bergmann U. , Gronwald F.
Published: July 2013

Abstract. This paper introduces a method for dead time optimization in variable speed motor drive systems. The aim of this method is to reduce the conduction time of the freewheeling diode to a minimum without generation of cross conduction. This results in lower losses, improved EMC, and less overshooting of the phase voltage. The principle of the method is to detect beginning cross currents without adding additional components in the half bridge like resistors or inductances. Only the wave shape of the phase voltage needs to be monitored during switching. This is illustrated by an application of the method to a real power converter.
Optimal design of active EMC filters
Authors: Chand B. , Kut T. , Dickmann S.
Published: July 2013

Abstract. A recent trend in automotive industry is adding electrical drive systems to conventional drives. The electrification allows an expansion of energy sources and provides great opportunities for environmental friendly mobility. The electrical powertrain and its components can also cause disturbances which couple into nearby electronic control units and communication cables. Therefore the communication can be degraded or even permanently disrupted. To minimize these interferences, different approaches are possible. One possibility is to use EMC filters. However, the diversity of filters is very large and the determination of an appropriate filter for each application is time-consuming. Therefore, the filter design is determined by using a simulation tool including an effective optimization algorithm. This method leads to improvements in terms of weight, volume and cost.
Matching the termination of radiating non-uniform transmission-lines
Authors: Rambousky R. , Nitsch J. , Garbe H.
Published: July 2013

Abstract. In this contribution a concept of matching the termination of radiating non-uniform transmission-lines is proposed. Using Transmission-Line Super Theory, position and frequency dependent line parameters can be obtained. Therefore, a characteristic impedance can be determined which is also position and frequency dependent. For a single wire transmission-line it could be shown that the maximum value of that characteristic impedance is an optimal termination in the sense of minimizing the variation of the current on the line. This indicates that matching is not a local effect at the position of the concentrated load but a cooperative process including the whole non-uniform transmission-line. In addition this choice of termination minimizes the variation of the radiated power over frequency.
Occurrence frequencies of polar mesosphere summer echoes observed at 69° N during a full solar cycle
Authors: Latteck R. , Bremer J.
Published: July 2013

Abstract. Polar mesosphere summer echoes (PMSE) are strong enhancements of received signal power at very high radar frequencies occurring at altitudes between about 80 and 95 km at polar latitudes during summer. PMSE are caused by inhomogeneities in the electron density of the radar Bragg scale within the plasma of the cold summer mesopause region in the presence of negatively charged ice particles. Thus the occurrence of PMSE contains information about mesospheric temperature and water vapour content but also depends on the ionisation due to solar wave radiation and precipitating high energetic particles. Continuous and homogeneous observations of PMSE have been done on the North-Norwegian island Andøya (69.3° N, 16.0° E) from 1999 until 2008 using the ALWIN VHF radar at 53.5 MHz. In 2009 the Leibniz-Institute of Atmospheric Physics in Kühlungsborn, Germany (IAP) started the installation of the Middle Atmosphere Alomar Radar System (MAARSY) at the same location. The observation of mesospheric echoes could be continued in spring 2010 starting with an initial stage of expansion of MAARSY and is carried out with the completed installation of the radar since May 2011. Since both the ALWIN radar and MAARSY are calibrated, the received echo strength of PMSE from 14 yr of mesospheric observations could be converted to absolute signal power. Occurrence frequencies based on different common thresholds of PMSE echo strength were used for investigations of the solar and geomagnetic control of the PMSE as well as of possible long-term changes. The PMSE are positively correlated with the solar Lyman α radiation and the geomagnetic activity. The occurrence frequencies of the PMSE show slightly positive trends but with marginal significance levels.
A relation between algebraic and transform-based reconstruction technique in computed tomography
Authors: Kiefhaber S. , Rosenbaum M. , Sauer-Greff W. , Urbansky R.
Published: July 2013

Abstract. In this contribution a coherent relation between the algebraic and the transform-based reconstruction technique for computed tomography is introduced using the mathematical means of two-dimensional signal processing. There are two advantages arising from that approach. First, the algebraic reconstruction technique can now be used efficiently regarding memory usage without considerations concerning the handling of large sparse matrices. Second, the relation grants a more intuitive understanding as to the convergence characteristics of the iterative method. Besides the gain in theoretical insight these advantages offer new possibilities for application-specific fine tuning of reconstruction techniques.
Evaluation of biospheric components in Earth system models using modern and palaeo observations: the state-of-the-art
Authors: Foley A. M. , Dalmonech D. , Friend A. D. , Aires F. , Archibald A. , Bartlein P. , Bopp L. , Chappellaz J. , Cox P. , Edwards N. R. , Feulner G. , Friedlingstein P. , Harrison S. P. , Hopcroft P. O. , Jones C. D. , Kolassa J. , Levine J. G. , Prentice I. C. , Pyle J. , Vázquez Riveiros N. , Wolff E. W. , Zaehle S.
Published: July 2013

Abstract. Earth system models are increasing in complexity and incorporating more processes than their predecessors, making them important tools for studying the global carbon cycle. However, their coupled behaviour has only recently been examined in any detail, and has yielded a very wide range of outcomes, with coupled climate-carbon cycle models that represent land-use change simulating total land carbon stores by 2100 that vary by as much as 600 Pg C given the same emissions scenario. This large uncertainty is associated with differences in how key processes are simulated in different models, and illustrates the necessity of determining which models are most realistic using rigorous model evaluation methodologies. Here we assess the state-of-the-art with respect to evaluation of Earth system models, with a particular emphasis on the simulation of the carbon cycle and associated biospheric processes. We examine some of the new advances and remaining uncertainties relating to (i) modern and palaeo data and (ii) metrics for evaluation, and discuss a range of strategies, such as the inclusion of pre-calibration, combined process- and system-level evaluation, and the use of emergent constraints, that can contribute towards the development of more robust evaluation schemes. An increasingly data-rich environment offers more opportunities for model evaluation, but it is also a challenge, as more knowledge about data uncertainties is required in order to determine robust evaluation methodologies that move the field of ESM evaluation from "beauty contest" toward the development of useful constraints on model behaviour.
Soil greenhouse gas fluxes from different tree species on Taihang Mountain, North China
Authors: Liu X. P. , Zhang W. J. , Hu C. S. , Tang X. G.
Published: July 2013

Abstract. The objectives of this study were to investigate seasonal variation of greenhouse gas fluxes from soils on sites dominated by plantation (Robinia pseudoacacia, Punica granatum, and Ziziphus jujube) and natural regenerated forests (Vitex negundo var. heterophylla, Leptodermis oblonga, and Bothriochloa ischcemum), and to identify how tree species, litter exclusion, and soil properties (soil temperature, soil moisture, soil organic carbon, total N, soil bulk density, and soil pH) explained the temporal and spatial variance in soil greenhouse gas fluxes. Fluxes of greenhouse gases were measured using static chamber and gas chromatography techniques. Six static chambers were randomly installed in each tree species. Three chambers were randomly designated to measure the impacts of surface litter exclusion, and the remaining three were used as a control. Field measurements were conducted biweekly from May 2010 through April 2012. Soil CO2 emissions from all tree species were significantly affected by soil temperature, soil moisture, and their interaction. Driven by the seasonality of temperature and precipitation, soil CO2 emissions demonstrated a clear seasonal pattern, with fluxes significantly higher during the rainy season than during the dry season. Soil CH4 and N2O fluxes were not significantly correlated with soil temperature, soil moisture, or their interaction, and no significant seasonal differences were detected. Soil CO2 and N2O fluxes were significantly correlated with soil organic carbon, total N, and soil bulk density, while soil pH was not correlated with CO2 and N2O emissions. Soil CH4 fluxes did not display pronounced dependency on soil organic carbon, total N, soil bulk density, and soil pH. Removal of surface litter resulted in significant decreases in CO2 emissions and CH4 uptakes, but had no significant influence on N2O fluxes. Soils in six tree species acted as sinks for atmospheric CH4. With the exception of Ziziphus jujube, Soils in all sites acted as sinks for atmospheric N2O. Tree species had a significant effect on CO2 and N2O fluxes but not on CH4 uptake. The lower net global warming potential in natural regenerated vegetation suggested that natural regenerated vegetation were more desirable plant species in reducing global warming.
Groundwater–surface water interactions, vegetation dependencies and implications for water resources management in the semi-arid Hailiutu River catchment, China – a synthesis
Authors: Zhou Y. , Wenninger J. , Yang Z. , Yin L. , Huang J. , Hou L. , Wang X. , Zhang D. , Uhlenbrook S.
Published: July 2013

Abstract. During the last decades, large-scale land use changes took place in the Hailiutu River catchment, a semi-arid area in northwest China. These changes had significant impacts on the water resources in the area. Insights into groundwater and surface water interactions and vegetation-water dependencies help to understand these impacts and formulate sustainable water resources management policies. In this study, groundwater and surface water interactions were identified using the baseflow index at the catchment scale, and hydraulic and water temperature methods as well as event hydrograph separation techniques at the sub-catchment scale. The results show that almost 90% of the river discharge consists of groundwater. Vegetation dependencies on groundwater were analysed from the relationship between the Normalized Difference Vegetation Index (NDVI) and groundwater depth at the catchment scale and along an ecohydrogeological cross-section, and by measuring the sap flow of different plants, soil water contents and groundwater levels at different research sites. The results show that all vegetation types, i.e. trees (willow (Salix matsudana) and poplar (Populus simonii), bushes (salix – Salix psammophila), and agricultural crops (maize – Zea mays)), depend largely on groundwater as the source for transpiration. The comparative analysis indicates that maize crops use the largest amount of water, followed by poplar trees, salix bushes, and willow trees. For sustainable water use with the objective of satisfying the water demand for socio-economical development and to prevent desertification and ecological impacts on streams, more water-use-efficient crops such as sorghum, barley or millet should be promoted to reduce the consumptive water use. Willow trees should be used as wind-breaks in croplands and along roads, and drought-resistant and less water-use intensive plants (for instance native bushes) should be used to vegetate sand dunes.
Water Accounting Plus (WA+) – a water accounting procedure for complex river basins based on satellite measurements
Authors: Karimi P. , Bastiaanssen W. G. M. , Molden D.
Published: July 2013

Abstract. Coping with water scarcity and growing competition for water among different sectors requires proper water management strategies and decision processes. A pre-requisite is a clear understanding of the basin hydrological processes, manageable and unmanageable water flows, the interaction with land use and opportunities to mitigate the negative effects and increase the benefits of water depletion on society. Currently, water professionals do not have a common framework that links depletion to user groups of water and their benefits. The absence of a standard hydrological and water management summary is causing confusion and wrong decisions. The non-availability of water flow data is one of the underpinning reasons for not having operational water accounting systems for river basins in place. In this paper, we introduce Water Accounting Plus (WA+), which is a new framework designed to provide explicit spatial information on water depletion and net withdrawal processes in complex river basins. The influence of land use and landscape evapotranspiration on the water cycle is described explicitly by defining land use groups with common characteristics. WA+ presents four sheets including (i) a resource base sheet, (ii) an evapotranspiration sheet, (iii) a productivity sheet, and (iv) a withdrawal sheet. Every sheet encompasses a set of indicators that summarise the overall water resources situation. The impact of external (e.g., climate change) and internal influences (e.g., infrastructure building) can be estimated by studying the changes in these WA+ indicators. Satellite measurements can be used to acquire a vast amount of required data but is not a precondition for implementing WA+ framework. Data from hydrological models and water allocation models can also be used as inputs to WA+.
Basin-wide water accounting based on remote sensing data: an application for the Indus Basin
Authors: Karimi P. , Bastiaanssen W. G. M. , Molden D. , Cheema M. J. M.
Published: July 2013

Abstract. The paper demonstrates the application of a new water accounting plus (WA+) framework to produce information on depletion of water resources, storage change, and land and water productivity in the Indus basin. It shows how satellite-derived estimates of land use, rainfall, evaporation (E), transpiration (T), interception (I) and biomass production can be used in addition to measured basin outflow, for water accounting with WA+. It is demonstrated how the accounting results can be interpreted to identify existing issues and examine solutions for the future. The results for one selected year (2007) showed that total annual water depletion in the basin (501 km3) plus outflows (21 km3) exceeded total precipitation (482 km3). The water storage systems that were effected are groundwater storage (30 km3), surface water storage (9 km3), and glaciers and snow storage (2 km3). Evapotranspiration of rainfall or "landscape ET" was 344 km3 (69 % of total depletion). "Incremental ET" due to utilized flow was 157 km3 (31% of total depletion). Agriculture depleted 297 km3, or 59% of the total depletion, of which 85% (254 km3) was through irrigated agriculture and the remaining 15% (44 km3) through rainfed systems. Due to excessive soil evaporation in agricultural areas, half of all water depletion in the basin was non-beneficial. Based on the results of this accounting exercise loss of storage, low beneficial depletion, and low land and water productivity were identified as the main water resources management issues. Future scenarios to address these issues were chosen and their impacts on the Indus Basin water accounts were tested using the new WA+ framework.
A relative vulnerability estimation of flood disaster using data envelopment analysis in the Dongting Lake region of Hunan
Authors: Li C.-H. , Li N. , Wu L.-C. , Hu A.-J.
Published: July 2013

Abstract. The vulnerability to flood disaster is addressed by a number of studies. It is of great importance to analyze the vulnerability of different regions and various periods to enable the government to make policies for distributing relief funds and help the regions to improve their capabilities against disasters, yet a recognized paradigm for such studies seems missing. Vulnerability is defined and evaluated through either physical or economic–ecological perspectives depending on the field of the researcher concerned. The vulnerability, however, is the core of both systems as it entails systematic descriptions of flood severities or disaster management units. The research mentioned often has a development perspective, and in this article we decompose the overall flood system into several factors: disaster driver, disaster environment, disaster bearer, and disaster intensity, and take the interaction mechanism among all factors as an indispensable function. The conditions of flood disaster components are demonstrated with disaster driver risk level, disaster environment stability level and disaster bearer sensitivity, respectively. The flood system vulnerability is expressed as vulnerability = f(risk, stability, sensitivity). Based on the theory, data envelopment analysis method (DEA) is used to detail the relative vulnerability's spatiotemporal variation of a flood disaster system and its components in the Dongting Lake region. The study finds that although a flood disaster system's relative vulnerability is closely associated with its components' conditions, the flood system and its components have a different vulnerability level. The overall vulnerability is not the aggregation of its components' vulnerability. On a spatial scale, zones central and adjacent to Dongting Lake and/or river zones are characterized with very high vulnerability. Zones with low and very low vulnerability are mainly distributed in the periphery of the Dongting Lake region. On a temporal scale, the occurrence of a vibrating flood vulnerability trend is observed. A different picture is displayed with the disaster driver risk level, disaster environment stability level and disaster bearer sensitivity level. The flood relative vulnerability estimation method based on DEA is characteristic of good comparability, which takes the relative efficiency of disaster system input–output into account, and portrays a very diverse but consistent picture with varying time steps. Therefore, among different spatial and time domains, we could compare the disaster situations with what was reflected by the same disaster. Additionally, the method overcomes the subjectivity of a comprehensive flood index caused by using an a priori weighting system, which exists in disaster vulnerability estimation of current disasters.
Complementary methods to plan pedestrian evacuation of the French Riviera's beaches in case of tsunami threat: graph- and multi-agent-based modelling
Authors: Sahal A. , Leone F. , Péroche M.
Published: July 2013

Abstract. Small amplitude tsunamis have impacted the French Mediterranean shore (French Riviera) in the past centuries. Some caused casualties; others only generated economic losses. While the North Atlantic and Mediterranean tsunami warning system is being tested and is almost operational, no awareness and preparedness measure is being implemented at a local scale. Evacuation is to be considered along the French Riviera, but no plan exists within communities. We show that various approaches can provide local stakeholders with evacuation capacities assessments to develop adapted evacuation plans through the case study of the Cannes–Antibes region. The complementarity between large- and small-scale approaches is demonstrated with the use of macro-simulators (graph-based) and micro-simulators (multi-agent-based) to select shelter points and choose evacuation routes for pedestrians located on the beach. The first one allows automatically selecting shelter points and measuring and mapping their accessibility. The second one shows potential congestion issues during pedestrian evacuations, and provides leads for the improvement of urban environment. Temporal accessibility to shelters is compared to potential local and distal tsunami travel times, showing a 40 min deficit for an adequate crisis management in the first scenario, and a 30 min surplus for the second one.
Radiation Effects on Dissipative Magnetohydrodynamic Couette Flow in a Composite Channel
Authors: Vyas Paresh , Srivastava Nupur
Published: July 2013

This paper examines radiative thermal regime in dissipative magnetohydrodynamic (MHD) Couette flow in a composite parallel plate channel partially filled with a radiating fluid saturated porous medium and partially filled with a radiating clear fluid. The fluid is considered to be viscous, incompressible, optically dense, electrically conducting, and Newtonian. The radiative heat flux in the energy equation is assumed to follow the Rosseland approximation. Suitable matching conditions are used to match the momentum and thermal regimes in clear fluid and porous regions at the clear fluid-porous interface. The momentum and energy equations have closed form solutions. The effects of various parameters on the system are analyzed through graphs and tables.
Spontaneous vascular flora of selected cemeteries in Lublin and the surrounding area
Authors: Trzaskowska Ewa , Karczmarz Katarzyna
Published: July 2013

The experiment was conducted in 2011–2012. It included an analysis of the spontaneous flora of 7 cemeteries: 3 cemeteries located in the centre of Lublin (Lipowa Street, Unicka Street, and Kalina Street), 1 on the outskirts of the city (Majdanek), 1 located in a small town (Łęczna), 2 sites are rural cemeteries (Łuszczów, Ostrówek). An inventory was made of spontaneous vascular flora present at the investigated sites. The plants were described in respect of their affiliation to geographical-historical groups, life forms as well as the presence of honey species (polleniferous and nectariferous) and protected species. Within the area of these 7 necropolises, the presence of 382 taxa was found. The number of taxa observed at the individual sites varied between 124 and 274 in the metropolitan zone, 146 in the urban zone, and between 110 and 146 in the rural areas.

The area richest in terms of flora was Majdanek where 274 species of plants were found, while the cemetery in Łuszczów was the least rich – 110 species. The highest precentage of hemicryptophytes was observed in Ostrówek (50.7%), the lowest in Lublin – Kalina (40.3%). In the case of therophytes, the greatest variation was observed in the urban cemetery in Unicka Street (32.6%), while the least varied site was the cemetery in Ostrówek (23.3%). The average precentage of geophytes was 12.1%, with the greatest number in Łuszczów (16.4%), and the smallest one in Majdanek (8.4%). Chamaephytes were characterised by a small percentage (between 5.1% and 4.4 %), similarly to nanophanerophytes (6.2% to 2.7%), and megaphanerophytes (9.6%–1.8%). The investigated sites were dominated by apophytes, the percentage of which varied between 52.3% in the Lublin cemeteries on Lipowa and Unicka Streets, and 44.5% in Ostrówek.

Among anthropophytes, there were mostly archeophytes (between 26.3% in Łuszczów and 13.1% on Lipowa St. in Lublin). The percentage of diaphytes varied between 16.5% in Ostrówek and 7.2% in Lublin – Kalina, whereas that of kenophytes was between 15.1% in Ostrówek and 8.2% in Łęczna. In the case of spontaneophytes, the percentage varied between 8.8% in Lublin – Majdanek and 2.7% in Łuszczów. The majority, 299 of the taxa found, proved invaluable to insects (polleniferous and nectariferous). Among the plants growing spontaneously in the analysed cemeteries, there were also 11 legally protected species.
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Impact on ART initiation of point‐of‐care CD4 testing at HIV diagnosis among HIV‐positive youth in Khayelitsha, South Africa
Authors: Patten Gabriela EM , Wilkinson Lynne , Conradie Karien , Isaakidis Petros , Harries Anthony D , Edginton Mary E , De Azevedo Virginia , van Cutsem Gilles
Published: July 2013

Introduction

Despite the rapid expansion of antiretroviral therapy (ART) programmes in developing countries, pre‐treatment losses from care remain a challenge to improving access to treatment. Youth and adolescents have been identified as a particularly vulnerable group, at greater risk of loss from both pre‐ART and ART care. Point‐of‐care (POC) CD4 testing has shown promising results in improving linkage to ART care. In Khayelitsha township, South Africa, POC CD4 testing was implemented at a clinic designated for youth aged 12–25 years. We assessed whether there was an associated reduction in attrition between HIV testing, assessment for eligibility and ART initiation.

Methods

A before‐and‐after observational study was conducted using routinely collected data. These were collected on patients from May 2010 to April 2011 (Group A) when baseline CD4 count testing was performed in a laboratory and results were returned to the clinic within two weeks. Same‐day POC CD4 testing was implemented in June 2011, and data were collected on patients from August 2011 to July 2012 (Group B).

Results

A total of 272 and 304 youth tested HIV‐positive in Group A and Group B, respectively. Group B patients were twice as likely to have their ART eligibility assessed compared to Group A patients: 275 (90%) vs. 183 (67%) [relative risk (RR)=2.4, 95% CI: 1.8–3.4, p<0.0001]. More patients in World Health Organization (WHO) Stage 1 disease (85% vs. 69%), with CD4 counts≥350 cells/µL (58% vs. 35%) and more males (13% vs. 7%) were detected in Group B. The proportion of eligible patients who initiated ART was 50% and 44% (p=0.6) in Groups B and A, respectively; and 50% and 43% (p=0.5) when restricted to patients with baseline CD4 count≤250 cells/µL. Time between HIV‐testing and ART initiation was reduced from 36 to 28 days (p=0.6).

Discussion

POC CD4 testing significantly improved assessment for ART eligibility. The improvement in the proportion initiating ART and the reduction in time to initiation was not significant due to sample size limitations.

Conclusions

POC CD4 testing reduced attrition between HIV‐testing and assessment of ART eligibility. Strategies to improve uptake of ART are needed, possibly by improving patient support for HIV‐positive youth immediately after diagnosis.
On the syntax and semantics of Spanish spatial prepositions
Authors: Ursini Francesco-Alessio
Published: July 2013

The goal of this paper is to offer a novel account on the Syntax and Semantics of Spanish Spatial Prepositions. This account is novel in at least three aspects. First, the account offers a unified syntactic analysis that covers understudied types of Spanish Spatial Prepositions (e.g. en el centro de, junto y a la izquierda de). Second, the account shows that such treatment can be extended to morphological phenomena, and can capture both their internal structure (e.g. de-bajo), and licensing patterns pertaining to argument demotion. The account also captures an alternation between "a-" (e.g. alante) and "de-" Prepositions (e.g. debajo), with respect to demotion, and is consistent with standard treatments of where-questions (dónde, in Spanish). Third, the account offers a "direct compositionality" semantic treatment, in which the interpretation of Spanish Spatial Prepositions is directly "read off" from their structure. This account is shown to capture all the semantic data discussed in the paper (argument demotion, interaction of Prepositions with Verbs, coordinated Prepositions), and to successfully extend previous accounts of this category.

 
Stage and Individual-level predicates whithin "if" and "when" clauses: what works and what doesn't
Authors: Martínez-Arbelaiz Asuncion
Published: July 2013

Clauses headed by if and when are very often considered syntactically and semantically equivalent.  Nevertheless, in this paper we show that the type of predicate has an impact both on the grammaticality and the interpretation of the subordinate clause in Spanish. Theses clauses provide evidence for the proposal that stage-level predicates involve an extra-argument that individual-level predicates lack. Following Kratzer (1995), we assume that this is extra-argument is a spatio-temporal argument. While stage-level predicates in the subordinate clause are perfectly grammatical, individual-level predicates yield to ungrammatical sentences, unless an indefinite or a kind-referring NP is involved.  Kratzer´s Prohibition against vacuous quantification provides a sound account for the asymmetry between the two types of predicates.  In addition, a stative verb in the when clause is grammatical, but it forces an epistemic reading. When both predicates are individual-level predicates in the subordinate and the main clause, the if clause may can take a factual reading while the when clause is ungrammatical unless there is some kind of operator involved through a generic, a kind-referring NP or an indefinite pronoun.
Ribosomal RNA Depletion for Efficient Use of RNA‐Seq Capacity
Authors: O'Neil Dominic , Glowatz Heike , Schlumpberger Martin
Published: July 2013

Ribosomal RNA (rRNA) is the most highly abundant component of RNA, comprising the majority (>80% to 90%) of the molecules present in a total RNA sample. Depletion of this rRNA fraction is desirable prior to performing an RNA‐seq reaction, so that sequencing capacity can be focused on more informative parts of the transcriptome. This unit describes an rRNA depletion method based on selective hybridization of oligonucleotides to rRNA, recognition with a hybrid‐specific antibody, and removal of the antibody‐hybrid complex on magnetic beads. Curr. Protoc. Mol. Biol. 103:4.19.1–4.19.8. © 2013 by John Wiley & Sons, Inc.
Watson Urges Measures to Minimize Climate Change
Authors: Showstack Randy
Published: July 2013

Professor Sir Robert Watson is not optimistic that atmospheric concentrations of greenhouse gas (GHG) emissions will be reduced before there is a 2‐degree Celsius increase, and possibly a much larger increase, in global temperatures above pre‐industrial temperature levels, he said recently. “There is no evidence politically that we are moving there, so clearly one has to be quite concerned,” said Watson, the chief scientific adviser to the U.K. Department for Environment, Food and Rural Affairs. He made the comments at the Union Frontiers of Geophysics Lecture and during a later presentation at the AGU Fall Meeting in San Francisco in December.
Assessing carbon storage in western U.S. ecosystems
Authors: Balcerak Ernie
Published: July 2013

Western U.S. ecosystems have the capacity to sequester about 91 million metric tons of carbon per year, according to a report released 5 December by the Department of the Interior. Entitled “Baseline and Projected Future Carbon Storage and Greenhouse‐Gas Fluxes in Ecosystems of the Western United States” and written by U.S. Geological Survey (USGS) scientists, the report came out of a congressionally mandated study. It examines how much carbon can be stored naturally through biological activity in various ecosystems, including forests, grasslands, and wetlands, in the western United States, from the Rocky Mountains to the Pacific.
Bowen, Dufek, and Shelly Receive 2012 James B. Macelwane Medals: Response
Authors: Dufek Josef
Published: July 2013

Thank you, Mark, for your kind words, and thanks also to AGU and the Macelwane committee for this unexpected honor, and to my nominators for their support.
James R. Rice Receives 2012 Walter H. Bucher Medal: Citation
Authors: Tullis Terry E.
Published: July 2013

James R. Rice was awarded the 2012 Walter H. Bucher Medal at the AGU Fall Meeting Honors Ceremony, held on 5 December 2012 in San Francisco, Calif. The medal is for “original contributions to the basic knowledge of the crust and lithosphere”.
Maria T. Zuber Receives 2012 Harry H. Hess Medal: Response
Authors: Zuber Maria T.
Published: July 2013

Thank you, Sean, and other colleagues who took the time to nominate me for this extraordinary honor. It is deeply meaningful to be recognized by the AGU, the primary scientific society in which I've participated throughout my career. The ever‐expanding reach of AGU provides an outlet for our research much beyond our immediate field, important because, as I tell my students: “It doesn't matter how good your work is if no one knows about it.” Viewing the list of distinguished past Hess recipients, many of whom have influenced me greatly, it is impossible to overstate how humbled I am.
Cresting the Ocean‐Outreach Wave, AGU Signs Memorandum of Understanding
Authors: McEntee Chris
Published: July 2013

Time and tide wait for no one, not even science educators. With this in mind, AGU and the Centers for Ocean Sciences Education Excellence (COSEE), recognizing our mutual interests and objectives, signed a memorandum of understanding in October 2012. The memorandum will serve to further AGU's strategic goals of informing society about the excitement of Earth and space science and building the global scientific talent pool.
Decompression wave caused eruption chain reaction
Authors: Schultz Colin
Published: July 2013

The 2010 eruption of Icelandic volcano Eyjafjallajökull proceeded through fits and starts. A new analysis by Tarasewicz et al. suggests that a downward propagating decompression wave triggered a cascade of explosive eruptions from sequentially deeper magma reservoirs. Drawing on detailed seismic measurements, the authors found that earthquake activity under the volcano propagated deeper into the subsurface as the eruption progressed. They found that at the onset of the explosive phase of the eruption on 14 April, magma was ejected from a chamber located 5 kilometers below the summit. Over subsequent weeks, the eruption calmed and the surface deflated as the subsurface magma chamber emptied. The authors suggest that the decreasing mass of the summit caused the pressure to drop in a subsurface pipeline that fed the main magma chamber.
Landsat 5 to be decommissioned
Authors: Showstack Randy
Published: July 2013

After orbiting the planet more than 150,000 times since its launch in 1984, the Landsat 5 Earth observing satellite is being decommissioned due to the recent failure of a gyroscope, the U.S. Geological Survey (USGS) announced on 21 December. The 29‐year‐old satellite originally had an expected design life of 3 years.
Studying Hydrological Properties and Processes at Scales From Centimeters to Watersheds
Authors: Knight Rosemary , Irving James , van der Kruk Jan
Published: July 2013

The Hydrogeophysics Workshop, jointly sponsored by the Society of Exploration Geophysicists and the American Geophysical Union (AGU), was held in Boise, Idaho. The workshop was organized to bring together the international hydrogeophysics community to discuss current approaches for determining, predicting, and studying hydrological properties and processes in both the saturated and unsaturated zones, at scales ranging from centimeters to watersheds.
Planning the Drilling of the Samail Ophiolite in Oman
Authors: Kelemen Peter
Published: July 2013

For more than a decade, plans have been afoot for scientific drilling in the Samail ophiolite in Oman. The ophiolite is a thrust sheet of oceanic crust and shallow mantle, emplaced on the Arabian continental margin 95 to 70 million years ago, which has tilted and eroded so that one can now observe sections extending from 0 to more than 15 kilometers below the paleo‐seafloor. Plans to study formation and evolution of the ophiolite have been spurred by recent interest in ongoing alteration and weathering, the associated sub‐surface biosphere, and the possibility of carbon storage via accelerated mineral carbonation.
Zuyin Pu Receives 2012 International Award: Citation
Authors: Kivelson Margaret
Published: July 2013

Zuyin Pu received the 2012 International Award at the AGU Fall Meeting Honors Ceremony, held on 5 December 2012 in San Francisco, Calif. The award honors “an individual scientist or a small team for making an outstanding contribution to furthering the Earth and space sciences and using science for the benefit of society in less favored nations.
Michelle Kathleen Hall Receives the 2012 Excellence in Geophysical Education Award: Citation
Authors: Mayhew Michael
Published: July 2013

Michelle Kathleen Hall received the 2012 Excellence in Geophysical Education Award at the AGU Fall Meeting Honors Ceremony, held on 5 December 2012 in San Francisco, Calif. The award honors “a sustained commitment to excellence in geophysical education by a team, individual, or group.”