bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ideas and perspectives: climate-relevant marine biologically driven mechanisms in Earth system models
Authors: Hense Inga , Stemmler Irene , Sonntag Sebastian 
Published: January 2017

Abstract. The current generation of marine biogeochemical modules in Earth system models (ESMs) considers mainly the effect of marine biota on the carbon cycle. We propose to also implement other biologically driven mechanisms in ESMs so that more climate-relevant feedbacks are captured. We classify these mechanisms in three categories according to their functional role in the Earth system: (1) biogeochemical pumps, which affect the carbon cycling; (2) biological gas and particle shuttles, which affect the atmospheric composition; and (3) biogeophysical mechanisms, which affect the thermal, optical, and mechanical properties of the ocean. To resolve mechanisms from all three classes, we find it sufficient to include five functional groups: bulk phyto- and zooplankton, calcifiers, and coastal gas and surface mat producers. We strongly suggest to account for a larger mechanism diversity in ESMs in the future to improve the quality of climate projections.
Onafhankelijke commissarissen en beloning in aandelen: een terugblik
Authors: Muhammad A. 
Published: January 2017

Onafhankelijke commissarissen en beloning in aandelen: een terugblik
Commissarissen dienen hun taken op onafhankelijke wijze uit te oefenen. In dit artikel staat de vraag centraal hoe beloning in aandelen – zoals voorgesteld in het consultatievoorstel voor de Corporate Governance Code – zich verenigt met die voorgeschreven onafhankelijke taakvervulling.
Mise en relief des difficultés pour les acteurs des comités des élèves au primaire : élèves, enseignants, directions d’établissements
Authors: Pache-Hébert Catherine , Jutras France , Guay Jean-Herman 
Published: January 2017

Le comité des élèves est une structure de participation des élèves à la gouvernance scolaire dans laquelle les élèves délégués représentent l’ensemble des élèves auprès de la direction et des membres du personnel. Bien qu’un apport éducatif soit indéniable, plusieurs difficultés entravent ses travaux. L’objectif de la recherche est de relever les difficultés du comité des élèves pour des acteurs : élèves délégués, enseignants qui l’encadrent et directions d’établissements. Au cours d’une année scolaire, les acteurs de comités des élèves de quatre écoles primaires de la région de Montréal ont pris part à la recherche. Les données ont été recueillies au moyen d’entretiens individuels et de groupes, ainsi que de l’observation participante. Les résultats montrent la complexité de cette instance et des difficultés relatives aux rôles des divers acteurs et à son fonctionnement. Plusieurs aspects qui relèvent de la gouvernance ainsi que de dynamiques sociologiques et psychologiques doivent être mieux compris pour que le comité des élèves atteigne ses visées éducatives.
Quantifying biomass consumption and carbon release from the California Rim fire by integrating airborne LiDAR and Landsat OLI data
Authors: Garcia Mariano , Saatchi Sassan , Casas Angeles , Koltunov Alexander , Ustin Susan , Ramirez Carlos , Garcia‐Gutierrez Jorge , Balzter Heiko 
Published: January 2017

AbstractQuantifying biomass consumption and carbon release is critical to understanding the role of fires in the carbon cycle and air quality. We present a methodology to estimate the biomass consumed and the carbon released by the California Rim fire by integrating postfire airborne LiDAR and multitemporal Landsat Operational Land Imager (OLI) imagery. First, a support vector regression (SVR) model was trained to estimate the aboveground biomass (AGB) from LiDAR‐derived metrics over the unburned area. The selected model estimated AGB with anR2of 0.82 and RMSE of 59.98 Mg/ha. Second, LiDAR‐based biomass estimates were extrapolated to the entire area before and after the fire, using Landsat OLI reflectance bands, Normalized Difference Infrared Index, and the elevation derived from LiDAR data. The extrapolation was performed using SVR models that resulted inR2of 0.73 and 0.79 and RMSE of 87.18 (Mg/ha) and 75.43 (Mg/ha) for the postfire and prefire images, respectively. After removing bias from the AGB extrapolations using a linear relationship between estimated and observed values, we estimated the biomass consumption from postfire LiDAR and prefire Landsat maps to be 6.58 ± 0.03 Tg (1012 g), which translate into 12.06 ± 0.06 Tg CO2ereleased to the atmosphere, equivalent to the annual emissions of 2.57 million cars.
Multiple metabolisms constrain the anaerobic nitrite budget in the Eastern Tropical South Pacific
Authors: Babbin Andrew R. , Peters Brian D. , Mordy Calvin W. , Widner Brittany , Casciotti Karen L. , Ward Bess B. 
Published: January 2017

AbstractThe Eastern Tropical South Pacific is one of the three major oxygen deficient zones (ODZs) in the global ocean and is responsible for approximately one third of marine water column nitrogen loss. It is the best studied of the ODZs and, like the others, features a broad nitrite maximum across the low oxygen layer. How the microbial processes that produce and consume nitrite in anoxic waters interact to sustain this feature is unknown. Here we used 15N‐tracer experiments to disentangle five of the biologically mediated processes that control the nitrite pool, including a high‐resolution profile of nitrogen loss rates. Nitrate reduction to nitrite likely depended on organic matter fluxes, but the organic matter did not drive detectable rates of denitrification to N2. However, multiple lines of evidence show that denitrification is important in shaping the biogeochemistry of this ODZ. Significant rates of anaerobic nitrite oxidation at the ODZ boundaries were also measured. Iodate was a potential oxidant that could support part of this nitrite consumption pathway. We additionally observed N2 production from labeled cyanate and postulate that anammox bacteria have the ability to harness cyanate as another form of reduced nitrogen rather than relying solely on ammonification of complex organic matter. The balance of the five anaerobic rates measured—anammox, denitrification, nitrate reduction, nitrite oxidation, and dissimilatory nitrite reduction to ammonium—is sufficient to reproduce broadly the observed nitrite and nitrate profiles in a simple one‐dimensional model but requires an additional source of reduced nitrogen to the deeper ODZ to avoid ammonium overconsumption.
Bubble formation and decrepitation control theCO2content of olivine‐hosted melt inclusions
Authors: Maclennan J. 
Published: January 2017

AbstractThe CO2contents of olivine‐hosted melt inclusions have previously been used to constrain the depth of magma chambers in basaltic systems. However, the vast majority of inclusions have CO2contents which imply entrapment pressures that are significantly lower than those obtained from independent petrological barometers. Furthermore, a global database of melt inclusion compositions from lowsettings, indicates that the distribution of saturation pressures varies surprisingly little between mid‐ocean ridges, ocean islands, and continental rift zones. 95% of the inclusions in the database have saturation pressures of 200 MPa or less, indicating that melt inclusion CO2does not generally provide an accurate estimate of magma chamber depths. A model of theP‐V‐T‐Xevolution of olivine‐hosted melt inclusions was developed so that the properties of the inclusion system could be tracked as the hosts follow a modelP‐Tpath. The models indicate that the principal control on the saturation of CO2in the inclusion and the formation of vapor bubbles is the effect of postentrapment crystallization on the major element composition of the inclusions and how this translates into variation in CO2solubility. The pressure difference between external melt and the inclusion is likely to be sufficiently high to cause decrepitation of inclusions in most settings. Decrepitation can account for the apparent mismatch between CO2‐based barometry and other petrological barometers, and can also account for the observed global distribution of saturation pressures. Only when substantial postentrapment crystallization occurs can reconstructed inclusion compositions provide an accurate estimate of magma chamber depth.
Predicting the severity of spurious “double ITCZ” problem in CMIP5 coupled models from AMIP simulations
Authors: Xiang Baoqiang , Zhao Ming , Held Isaac M. , Golaz Jean‐Christophe 
Published: January 2017

AbstractThe severity of the double Intertropical Convergence Zone (DI) problem in climate models can be measured by a tropical precipitation asymmetry index (PAI), indicating whether tropical precipitation favors the Northern Hemisphere or the Southern Hemisphere. Examination of 19 Coupled Model Intercomparison Project phase 5 models reveals that the PAI is tightly linked to the tropical sea surface temperature (SST) bias. As one of the factors determining the SST bias, the asymmetry of tropical net surface heat flux in Atmospheric Model Intercomparison Project (AMIP) simulations is identified as a skillful predictor of the PAI change from an AMIP to a coupled simulation, with an intermodel correlation of 0.90. Using tropical top‐of‐atmosphere (TOA) fluxes, the correlations are lower but still strong. However, the extratropical asymmetries of surface and TOA fluxes in AMIP simulations cannot serve as useful predictors of the PAI change. This study suggests that the largest source of the DI bias is from the tropics and from atmospheric models.
High permeability explains the vulnerability of the carbon store in drained tropical peatlands
Authors: Baird Andy J. , Low Robert , Young Dylan , Swindles Graeme T. , Lopez Omar R. , Page Susan 
Published: January 2017

AbstractTropical peatlands are an important global carbon (C) store but are threatened by drainage for palm oil and wood pulp production. The store's stability depends on the dynamics of the peatland water table, which in turn depend on peat permeability. We found that an example of the most abundant type of tropical peatland—ombrotrophic domes—has an unexpectedly high permeability similar to that of gravel. Using computer simulations of a natural peat dome (NPD) and a ditch‐drained peat dome (DPD) we explored how such high permeability affects water tables and peat decay. High permeability has little effect on NPD water tables because of low hydraulic gradients from the center to the margin of the peatland. In contrast, DPD water tables are consistently deep, leaving the upper meter of peat exposed to rapid decay. Our results reveal why ditch drainage precipitates a rapid destabilization of the tropical peatland C store.
Concerning the helium‐to‐hydrogen number density ratio in very slow ejecta and winds near solar minimum
Authors: Vasquez Bernard J. , Farrugia C. J. , Simunac K. D. C. , Galvin A. B. , Berdichevsky D. B. 
Published: January 2017

AbstractNear the solar minimum the average value of the helium‐to‐proton number density ratio is a strong function of speed. The average ratios for both solar ejecta and ambient winds obey approximately the same relation with speed. At the lowest speeds, the ratio takes on small values near and below 0.01. Here winds and ejecta with very slow speeds (310 km/s) are examined. STEREO and Wind spacecraft data are employed that were obtained from 2007 to 2010. This was during the prolonged solar activity minimum between cycles 23 and 24. Case event and statistical studies are made with 12 very slow ejecta. The helium‐to‐proton ratio in very slow ejecta relative to the ratio for very slow winds of comparable speed averaged in an inclusive 1 year period is 1.06. The ejecta and ambient slow winds have, then, nearly the same concentrations on average. The values did not approach 0 with decreasing speed and are shown to deviate from a predicted form. A survey of potential solar sources of very slow ejecta and other inferences based on interplanetary data found a strong correspondence with active regions and a dependence of the properties of very slow ejecta with the solar cycle.
Brown and Korringa constants for heterogeneous thinly layered poroelastic media
Authors: Wollner Uri , Mavko Gary 
Published: January 2017

AbstractMacromechanical characterization of a layered poroelastic package treated as a homogeneous (upscaled) medium is presented. The characterization is based on the knowledge of the poroelastic properties of the package's constituents. Specifically, we provide closed‐form expressions for the sum of the fourth‐order average elastic compliances tensor
of the solid frame and pore space compressibility 1/Kϕ, previously defined in Brown and Korringa's extended formulation of the Gassmann's fluid substitution equations. These constants allow, thus, to perform fluid substitution on an upscaled composite consisting of poroelastic layers. Each layer within the layered package is assumed to have isotropic symmetry, uniform porosity, and single pore‐filling fluid and composed of several homogeneously distributed mineral phases such that each layer is approximately Gassmann consistent; however, the fluid and mineral phases as well as the porosity may vary from one layer to the next along the package. In addition, we obtain insights into the sensitivity of
and 1/Kϕ when an approximate fluid substitution operation is used. Moreover, it is shown that the
of the upscaled medium can have transverse isotropy symmetry. The degree of anisotropy is controlled by the volume fractions of individual layers and the contrast of elastic properties between the layers. The results for
and 1/Kϕ are compared to those obtained by Berryman and Milton (BM) for a two‐phase isotropic composite. At a limiting case of an effectively isotropic medium, this paper's results coincide with those of BM.
Seasonality of the mass concentration and chemical composition of aerosols around an urbanized basin in East Asia
Authors: Chou C. C.‐K. , Hsu W.‐C. , Chang S.‐Y. , Chen W.‐N. , Chen M.‐J. , Huang W.‐R. , Huang S.‐H. , Tsai C.‐Y. , Chang S.‐C. , Lee C.‐T. , Liu S.‐C. 
Published: January 2017

AbstractThis study investigated seasonal variations in the mass concentration and chemical composition of ambient aerosols observed at three stations (coastal, mountainous, and downtown sites) in northern Taiwan from March 2009 to February 2012. The results show that the major aerosol components include ammonium, sulfate, nitrate, sea salt, dust, organic carbon, and elemental carbon, whereas the mass fraction of each species depends on the sampling location and season. A significant correlation (r = 0.7–0.8) was observed in aerosol concentrations measured at the respective stations, indicating that aerosol concentrations were dominated by regional‐scale factors. Ammonium, sulfate, and nitrate consistently reached respective peak values in the spring in conjunction with dust particle levels. This shows that the transport of dust and particulate air pollutants from the Asian continent has affected the atmospheric environment in this area. Distinct seasonality was observed for sea salt and secondary organic carbon (SOC): sea salt levels peaked in the autumn, whereas SOC levels peaked in the summer, implying that their sources were regulated by independent seasonal factors. Correlation between sea salt concentration and surface wind speed was derived from coastal measurements and showed a high value for the wind speed sensitivity parameter of around 0.37 for our location. In addition, it was revealed that the SOC concentration in aerosols was positively correlated with oxidant photolysis index (Ox × UVB), suggesting that the SOC seasonality was dominated by hydroxyl radical production.
Generation of real‐time mode high‐resolution water vapor fields from GPS observations
Authors: Yu Chen , Penna Nigel T. , Li Zhenhong 
Published: January 2017

AbstractPointwise GPS measurements of tropospheric zenith total delay can be interpolated to provide high‐resolution water vapor maps which may be used for correcting synthetic aperture radar images, for numeral weather prediction, and for correcting Network Real‐time Kinematic GPS observations. Several previous studies have addressed the importance of the elevation dependency of water vapor, but it is often a challenge to separate elevation‐dependent tropospheric delays from turbulent components. In this paper, we present an iterative tropospheric decomposition interpolation model that decouples the elevation and turbulent tropospheric delay components. For a 150 km × 150 km California study region, we estimate real‐time mode zenith total delays at 41 GPS stations over 1 year by using the precise point positioning technique and demonstrate that the decoupled interpolation model generates improved high‐resolution tropospheric delay maps compared with previous tropospheric turbulence‐ and elevation‐dependent models. Cross validation of the GPS zenith total delays yields an RMS error of 4.6 mm with the decoupled interpolation model, compared with 8.4 mm with the previous model. On converting the GPS zenith wet delays to precipitable water vapor and interpolating to 1 km grid cells across the region, validations with the Moderate Resolution Imaging Spectroradiometer near‐IR water vapor product show 1.7 mm RMS differences by using the decoupled model, compared with 2.0 mm for the previous interpolation model. Such results are obtained without differencing the tropospheric delays or water vapor estimates in time or space, while the errors are similar over flat and mountainous terrains, as well as for both inland and coastal areas.
Quantifying the causes of differences in tropospheric OH within global models
Authors: Nicely Julie M. , Salawitch Ross J. , Canty Timothy , Anderson Daniel C. , Arnold Steve R. , Chipperfield Martyn P. , Emmons Louisa K. , Flemming Johannes , Huijnen Vincent , Kinnison Douglas E. , Lamarque Jean‐François , Mao Jingqiu , Monks Sarah A. , Steenrod Stephen D. , Tilmes Simone , Turquety Solene 
Published: January 2017

AbstractThe hydroxyl radical (OH) is the primary daytime oxidant in the troposphere and provides the main loss mechanism for many pollutants and greenhouse gases, including methane (CH4). Global mean tropospheric OH differs by as much as 80% among various global models, for reasons that are not well understood. We use neural networks (NNs), trained using archived output from eight chemical transport models (CTMs) that participated in the Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, of Climate, Chemistry, Aerosols and Transport Model Intercomparison Project (POLMIP), to quantify the factors responsible for differences in tropospheric OH and resulting CH4 lifetime (τCH4) between these models. Annual average τCH4, for loss by OH only, ranges from 8.0 to 11.6 years for the eight POLMIP CTMs. The factors driving these differences were quantified by inputting 3‐D chemical fields from one CTM into the trained NN of another CTM. Across all CTMs, the largest mean differences in τCH4 (ΔτCH4) result from variations in chemical mechanisms (ΔτCH4 = 0.46 years), the photolysis frequency (J) of O3 → O(1D) (0.31 years), local O3 (0.30 years), and CO (0.23 years). The ΔτCH4 due to CTM differences in NOx (NO + NO2) is relatively low (0.17 years), although large regional variation in OH between the CTMs is attributed to NOx. Differences in isoprene and J(NO2) have negligible overall effect on globally averaged tropospheric OH, although the extent of OH variations due to each factor depends on the model being examined. This study demonstrates that NNs can serve as a useful tool for quantifying why tropospheric OH varies between global models, provided that essential chemical fields are archived.
2,3‐Pentandion [MAK Value Documentation in German language, 2017]
Authors: Hartwig Andrea ,   MAK‐Kommission
Published: January 2017

2,3‐Pentanedione [pentane‐2,3‐dione]The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated 2,3‐pentanedione to derive a maximum concentration at the workplace (MAK value), considering all toxicity endpoints. The critical effects of 2,3‐pentanedione were inflammation, necrosis, ulceration and fibrosis in the lung and inflammation, exudates and metaplasia in the nasal cavity in rats and mice after inhalation for 14 days. In this study the NOAEC in rats was 49 ml/m3and the LOAEC in mice was 49 ml/m3for effects in the lung. The occurrence of fibrosis after only two weeks of inhalation is assessed as a severe effect. Due to the structural similarity of 2,3‐pentanedione to diacetyl (2,3‐butanedione), which is responsible for bronchiolitis obliterans in popcorn workers, and the likeliness of lung effects in rodents, a MAK value of 0.02 ml/m3is set in analogy to diacetyl. As the critical effect is systemic, 2,3‐pentanedione is assigned to Peak Limitation Category II. The excursion factor of 1 is set in analogy to diacetyl. Skin contact may contribute significantly to systemic toxicity and 2,3‐pentanedione is designated with an “H”. In analogy to diacetyl, skin sensitization (Sh) is expected but not airway sensitization. Because there are no studies on developmental toxicity, the substance is assigned to Pregnancy Risk Group D. 2,3‐Pentanedione is neither genotoxic nor carcinogenic.
Electrochemistry of Organoaluminum Compounds
Authors: Shterenberg Ivgeni , Salama Michael , Gofer Yosef , Aurbach Doron 
Published: January 2017

Abstract
In this chapter, selected and the most important aspects of the electrochemistry of organoaluminum compounds are described. It is focused on two main implementations: electrochemical aluminum plating and rechargeable Mg batteries. Electrochemical aspects of organoaluminum‐based electroplating baths are discussed in detail and the effects of the solutions formulation on the electrochemical properties are explained. The role of organoaluminum compounds, acting as Lewis acids, in the formulation of the electrolyte solutions for rechargeable Mg batteries, and their effect on the performance of electrolyte solutions is described.
The Elephant in the Road: Auditory Perceptual Load Affects Driver Perception and Awareness
Authors: Murphy Gillian , Greene Ciara M. 
Published: January 2017

SummaryPerceptual load theory research has shown that the level of perceptual load in a task affects processing of additional information. Less certain are the cross‐modal effects of perceptual load—does load in one modality affect processing in another? The current study assessed the effect of auditory perceptual load on visual attention in a driving simulator task. While driving, participants listened to traffic updates on the radio, which imposed either low or high perceptual load. Awareness for an unexpected animal as well as less novel objects (such as billboards and other vehicles) was markedly reduced under high load. Driver behaviour was also significantly affected, with impaired lateral control, longer reaction times to hazards and more collisions under high load. This study has important implications for load theory and also more general implications for road safety, as it suggests that auditory load may be an important, often overlooked factor in driver attention.Copyright © 2017 John Wiley & Sons, Ltd.