bluuebunny/crossref_metadata_2025 huggingface dataset:
« Flirtant » avec la liturgie. Rois et liturgie en Gaule franque
Authors: Hen Yitzhak
Published: June 2012

During the VIIth century a change in emphasis came over western kingship — kings moved into an eccle- siastical atmosphere, and frequent biblical examples and citations were used to denote the Christian complexion of the newly formed political thought. One significant effect of this shift of emphasis was the emergence of the royal patronage of liturgy. In seventh century Francia, chants and prayers became an instrument by which heavenly protection was sought for the benefit of the kingdom and its ruler, and consequently kings and queens invested vast amounts of landed property and other privileges in order to secure the prayers on their behalf. This paper discusses the case of the Merovingian King Dagobert I, who was the first Frankish king to make ample use of the patronage of liturgy. Although unsuccessful in the long term, Dagobert's endeavour to institute a perpetual chant in Saint-Denis, following the model of Saint-Maurice of Agaune, is an important turning point in the history of the royal patronage of liturgy in Frankish Gaul. In his acts Dagobert established a pattern that was diligently followed by future kings and queens, not only Merovingian, but also Carolingian.
Le quartier Hors-Château : burgus de Liège ? Note sur l'évolution territoriale de la cité de Liège
Authors: Joris André
Published: June 2012

The city of Liège was walled as early as the year 1000 under the rule of the imperial bishop Notger (972-1008). The layout of these early fortifications was reconstructed by the mediaevalist historian Godefroid Kurth (1909). Yet, a number of future evidences (from archaeology, toponymy and parish history) are presently available that call for an updated approach. On such basis, one can figure a castral appendage named « Hors-Château » (wallon : « Fou-tchèstè ») around the St. Barthelemew collegiate church (ca 1016). This would have made up the Liège burgus, inhabited by castrenses among others. Close this vetus vicus (i.e. old burgh) urban craftsmen (black-smiths, potters, weavers ...) setteld in a novus vicus (i.e. new burgh) or « Neuvice », core of the subsequent town development. Another castral appendage, of a more military nature, was locatd near the St Martin collegiate church. Thus, the building up of the fortifications was not a random process.
Le cloître de Moissac a-t-il un programme ?
Authors: Fraïsse Chantai
Published: June 2012

L'iconographie du cloître roman de Saint-Pierre de Moissac, terminé en 1100, est très riche mais paradoxalement peu étudiée. Une tentative bien réfléchie de replacer l'œuvre dans son contexte intellectuel et idéologique, rend une lecture renouvelée de celle-ci possible. Dans le cloître même bien des indications confirment l'existence d'un lien intime et constant entre l'univers de la sculpture et celui des manuscrits du scriptorium, particulièrement actif à Moissac à la fin du XIe s. grâce à l'affiliation à Cluny. Les piliers de marbre et leurs images se présentent notamment comme la version plastique des incipit, colophons et auctoritates ouvrant et articulant les si nombreux commentaires bibliques de la patristique. Ces piliers et leur programme encadrent et cautionnent l'exercice d'exégèse en images des chapiteaux. Les images, ici de pierre, ont été jugées comme des moyens efficaces de faire surgir correctement, c'est-à-dire conformément à la Tradition, le sens spirituel des passages de l'Écriture sainte. Cette exégèse dans la pierre pourrait être le moyen de fixer dans la matière de l'enclos sacré la collatio (lecture commentée de l'Écriture) de l'abbé Ansquitil.
Poétique de l'expression de soi dans l'Alexandreis et la paraphrase du Psaume 50 de Gautier de Châtillon
Authors: Ganeva Martha
Published: June 2012

La mémorabilité du poème, en tant que propriété du message formel, peut-elle être liée à son caractère autobiographique ? La réponse se trouve peut-être dans l'œuvre de Gautier de Châtillon, poète d'expression latine de la fin du XII s., précurseur de ce qui deviendra au siècle suivant le courant poétique des Goliards. Auteur de poèmes rythmiques marqués par un fort caractère personnel, parmi lesquels la paraphrase du psaume 50 de l'Ancien Testament, Gautier est surtout, pour ses contemporains, l'auteur de génie de l'Alexandreis, poème épique en hexamètres dactyliques racontant le vie et la geste d'Alexandre le Grand.

Son œuvre semble ainsi partagée en deux entre les ludicra, composés sur le modèle de la poésie en langue vernaculaire, et l'épopée, modelée sur le genre noble de la poésie antique. Ce qui les unit pourtant, c'est cette figure de l'auteur désireux de se livrer à son lecteur : de manière directe, à travers la mise en scène du dialogue entre le poète et son œuvre dans le prologue de l'Alexandreis ; en s'inscrivant au-delà de l'ordre du discours et de la signification, dans la sonorité et le rythme de la poésie lyrique, dont la paraphrase du Psaume 50 constitue l'aboutissement.
À l'ombre de Cluny : l'hagiographie et la politique du portail de Saint-Hilaire de Semur-en-Brionnais
Authors: Heyman Avital
Published: June 2012

Cette étude est consacrée à la reconsidération du portail principal de l'église Saint-Hilaire à Semur-en-Brionnais, que l'on a qualifié jadis de « copie réduite » du Grand Portail disparu de Cluny III. Tandis que le tympan ne justifie que peu cette comparaison, le linteau semble volontairement prendre ses distances avec le supposé modèle de l'église abbatiale. Une analyse du style et du thème du portail de Saint-Hilaire place la sculpture dans le contexte de l'école romane régionale du Brionnais. Mais le principal objet de cette étude est le programme iconographique et la position tant des seigneurs que de la communauté religieuse de Semur vis-à-vis des choix politiques clunisiens. Le linteau de Semur contient une des rares représentations du concile schismatique convoqué à Séleucie en 359. Selon nous, ce choix thématique est lié au schisme papal des années 1160, en particulier à ces implications pour la Bourgogne et Cluny. Un concile schismatique convoqué en Bourgogne en 1162 ainsi que l'abbatiat d'un abbé schismatique à Cluny semblent être les cibles spécifiques de l'iconographie du linteau. Par conséquent, la datation post quem de 1164 est suggérée pour le portail en question. Ainsi, une analyse minutieuse de la dichotomie modèle/copie de Cluny/Semur mène à la conclusion que le portail de Semur ne fut pas conçu comme une copie fidèle de son modèle glorifié. Il semble que la situation politique tristement célèbre impliquant Cluny et la région, a conduit les seigneurs de Semur, dans l'enceinte fortifiée desquels se trouvait l'église, et la communauté religieuse à exprimer leur désapprobation politique de Cluny par le biais de leur choix du sujet. Et dès lors, au lieu d'être un modèle glorifié, Cluny constitua peut-être un anti-modèle, servant de point de départ et de base argumentative à une forme monumentale de discours. Les convictions anti-hérétiques de saint Hilaire peuvent être interprétées ici comme mode de transmission d'un paradigme idéologique, remplaçant l'ancien paradigme de l'histoire de l'art, choisi tant par la communauté de Saint-Hilaire que par les seigneurs de Semur dans leur opposition aux schismatiques contemporains.
Molecular monitoring of the development of intestinal microbiota in Japanese infants
Authors: Tsuji H. , Oozeer R. , Matsuda K. , Matsuki T. , Ohta T. , Nomoto K. , Tanaka R. , Kawashima M. , Kawashima K. , Nagata S. , Yamashiro Y.
Published: June 2012

The faecal microbiota of 166 healthy Japanese newborns was analysed periodically from day 1 after birth until the age of 3 years by using the reverse transcription-quantitative PCR. Faecal pH and the organic acid concentration were also examined. Colonisation by both facultative anaerobes and strict anaerobes was confirmed in 95% of the meconium tested. Bifidobacterium-predominant microbiota was established subsequently in most of the infants by 3 months after birth. Bifidobacterium breve, Bifidobacterium longum, Bifidobacterium infantis, Bifidobacterium catenulatum group and Bifidobacterium bifidum were the species mainly detected. Intergroup correlation analysis revealed that the bifidobacterial population levels, but not other strict anaerobe groups, were found to be negatively correlated with those of the Enterobacteriaceae from 7 days until 3 months after birth. Faecal pH was maintained at about 6 until 6 months after birth and reached 6.6 at 3 years after birth. The initial concentration of faecal organic acids (19 μM/g of faeces) just after birth increased until 3 years after birth to the level of 111 μM/g of faeces. Early start of feeding formula milk promoted colonisation by obligate anaerobes such as the Clostridium coccoides group, the Clostridium leptum subgroup, Prevotella, and Atopobium cluster during the 3 months after birth. Population levels of the bifidobacteria until 1 month after birth and those of the Bacteroides fragilis group until 6 months after birth were lower in infants delivered by Caesarean section than in those delivered normally. The results suggested that both earlier start of feeding of formula milk and the mode of infant delivery were found to be important in the development of intestinal microbiota in early infancy.
The Thal-Index with the BTT Prediction.exe to Discriminate β-Thalassaemia Traits from Other Microcytic Anaemias
Authors: Nishad Ahangama Arachchige Nilanga , Pathmeswaran Arunasalam , Wickramasinghe Ananda Rajitha , Premawardhena Anuja
Published: June 2012

Several attempts have been made previously to differentiate β-thalassaemia trait (BTT) from other microcytic anaemias using formulae with red cell (RC) parameters. Presently available formulae have low sensitivity and specificity. We wanted to develop a more precise algorithm, which could be used in situations where the gold-standard test for thalassaemia diagnosis: the high performance liquid chromatography (HPLC) is not available. The study was carried out prospectively from November 2008 to March 2010 from randomly collected blood samples with a mean cell volume (MCV) of less than 80 fL. HbA2 measured by HPLC was used to diagnose BTT. We used Fishers stepwise linear discriminant function analysis to develop an algorithm with RC parameters. Calculated new index Thal-index was then subjected to receiver operating characteristic curve analysis to identify best cutoff to discriminate BTT from other microcytic blood films. Software was developed to predict the BTT status (BTT prediction.exe). New index, referred to as the Thal-index, was calculated using discriminant function analysis and is given as Thal-index = [(0.615 x MCV) + (0.518 x mean corpuscular hemoglobin) + (0.446 x red cell distribution width)]. A value of 59 for Thal-index has 90% sensitivity and 85% specificity for differentiating BTT from other microcytic anaemias. This showed better sensitivity and specificity compared to other formulae presently used (i.e., Mentzer in Eshani, et al.). Our study gives a better answer to set-up where HPLC is not available. Although this cannot replace HPLC, BTT prediction.exe is useful to predict instantly and is the first ever computer program available for this function.
Variability of levels and composition of PM10 and PM2.5 in the Barcelona metro system
Authors: Querol X. , Moreno T. , Karanasiou A. , Reche C. , Alastuey A. , Viana M. , Font O. , Gil J. , de Miguel E. , Capdevila M.
Published: June 2012

Abstract. From an environmental perspective, the underground metro system is one of the cleanest forms of public transportation in urban agglomerations. Current studies report contradicting results regarding air quality in the metro systems: whereas some reveal poor air quality, others report PM levels which are lower or of the same order of magnitude than those measured in traffic sites above ground level. The present work assesses summer and winter indoor air quality and passenger exposure in the Barcelona metro, focusing on PM levels and their metal contents. In addition, the impact on indoor air quality of platform screen door systems (automated systems consisting of closed rail track and platforms) is evaluated, to determine whether these systems reduce passenger exposure to PM when compared with conventional systems (open tracks and platforms). In the Barcelona metro PM levels inside the trains in summer are amongst the lowest reported for worldwide metro systems (11–32 μg m−3 PM2.5). This is most likely due to the air conditioning system working in all carriages of the Barcelona metro during the whole year. Levels were considerably higher on the platforms, reaching mean levels of 46 and 125 μg m3 in the new (L9) and old (L3) lines, respectively. PM10 data are also reported in the present study, but comparison with other metro systems is difficult due to the scarcity of data compared with PM2.5. Results showed distinct PM daily cycles, with a drastic increase from 06:00 to 07:00 a.m., a diurnal maximum from 07:00 to 10:00 p.m., and marked decrease between 10:00 p.m. and 05:00 a.m. The elements with the highest enrichment were those associated with wheel or brake abrasion products (Ba, Fe, Cu, Mn, Cr, Sb, As, Mo, Co, Sr, among others). Laminar hematite (Fe2O3) was the dominant particle type, being mainly originated by mechanical abrasion of the rail track and wheels. Regarding passenger exposure to PM, the contribution of commuting by metro was estimated to account for around 10% of the daily exposure. However, this contribution may be one order of magnitude higher when specific matals are considered. Finally, we conclude that the implementation of platform screen door systems results in reductions of both PM levels and metal concentrations. In addition an advanced optimized ventilation system gave even a much higher efficiency in reducing exposure to PM of metro commuters. Combining these two features PM exposure levels in the platforms may be reduced down by a factor of 7 with respect the old subway lines in Barcelona.
Speciated mercury at marine, coastal, and inland sites in New England – Part 1: Temporal variability
Authors: Mao H. , Talbot R.
Published: June 2012

Abstract. A comprehensive analysis was conducted using long-term continuous measurements of gaseous elemental mercury (Hg0), reactive gaseous mercury (RGM), and particulate phase mercury (HgP) at coastal (Thompson Farm, denoted as TF), marine (Appledore Island, denoted as AI), and elevated inland (Pac Monadnock, denoted as PM) sites from the AIRMAP Observatories in southern New Hampshire, USA. Decreasing trends in background Hg0 were identified in the 7.5- and 5.5-yr records at TF and PM with decline rates of 3.3 parts per quadrillion by volume (ppqv) yr−1 and 6.3 ppqv yr−1, respectively. Common characteristics at these sites were the reproducible annual cycle of Hg0 with its maximum in winter-spring and minimum in fall, comprised of a positive trend in the warm season (spring – early fall) and a negative one in the cool season (late fall – winter). Year-to-year variability was observed in the warm season decline in Hg0 at TF varying from a minimum total (complete) seasonal loss of 43 ppqv in 2009 to a maximum of 92 ppqv in 2005, whereas variability remained small at AI and PM. The coastal site TF differed from the other two sites with its exceptionally low levels (as low as below 50 ppqv) in the nocturnal inversion layer possibly due to dissolution in dew water. Measurements of Hg0 at PM exhibited the smallest diurnal to annual variability among the three environments, where peak levels rarely exceeded 250 ppqv and the minimum was typically 100 ppqv. It should be noted that summertime diurnal patterns at TF and AI were opposite in phase indicating strong sink(s) for Hg0 during the day in the marine boundary layer, which was consistent with the hypothesis of Hg0 oxidation by halogen radicals there. Mixing ratios of RGM in the coastal and marine boundary layers reached annual maxima in spring and minima in fall, whereas at PM levels were generally below the limit of detection (LOD) except in spring. RGM levels at AI were higher than at TF and PM indicating a stronger source strength in the marine environment. Mixing ratios of HgP at AI and TF were close in magnitude to RGM levels and were mostly below 1 ppqv. Diurnal variation in HgP was barely discernible at TF and AI in spring and summer. Higher levels of HgP were observed during the day, while values that were smaller, but above the LOD, occurred at night.
Influence of air quality model resolution on uncertainty associated with health impacts
Authors: Thompson T. M. , Selin N. E.
Published: June 2012

Abstract. We use regional air quality modeling to evaluate the impact of model resolution on uncertainty associated with the human health benefits resulting from proposed air quality regulations. Using a regional photochemical model (CAMx), we ran a modeling episode with meteorological inputs representing conditions as they occurred during August through September 2006, and two emissions inventories (a 2006 base case and a 2018 proposed control scenario, both for Houston, Texas) at 36, 12, 4 and 2 km resolution. The base case model performance was evaluated for each resolution against daily maximum 8-h averaged ozone measured at monitoring stations. Results from each resolution were more similar to each other than they were to measured values. Population-weighted ozone concentrations were calculated for each resolution and applied to concentration response functions (with 95% confidence intervals) to estimate the health impacts of modeled ozone reduction from the base case to the control scenario. We found that estimated avoided mortalities were not significantly different between 2, 4 and 12 km resolution runs, but 36 km resolution may over-predict some potential health impacts. Given the cost/benefit analysis requirements of the Clean Air Act, the uncertainty associated with human health impacts and therefore the results reported in this study, we conclude that health impacts calculated from population weighted ozone concentrations obtained using regional photochemical models at 36 km resolution fall within the range of values obtained using fine (12 km or finer) resolution modeling. However, in some cases, 36 km resolution may not be fine enough to statistically replicate the results achieved using 2 and 4 km resolution. On average, when modeling at 36 km resolution, 7 deaths per ozone month were avoided because of ozone reductions resulting from the proposed emissions reductions (95% confidence interval was 2–9). When modeling at 2, 4 or 12 km finer scale resolution, on average 5 deaths were avoided due to the same reductions (95% confidence interval was 2–7). Initial results for this specific region show that modeling at a resolution finer than 12 km is unlikely to improve uncertainty in benefits analysis. We suggest that 12 km resolution may be appropriate for uncertainty analyses in areas with similar chemistry, but that resolution requirements should be assessed on a case-by-case basis and revised as confidence intervals for concentration-response functions are updated.
Wavelength and NOx dependent complex refractive index of SOAs generated from the photooxidation of toluene
Authors: Nakayama T. , Sato K. , Matsumi Y. , Imamura T. , Yamazaki A. , Uchiyama A.
Published: June 2012

Abstract. Recently, secondary organic aerosols (SOAs) generated from anthropogenic volatile organic compounds have been proposed as a possible source of lightabsorbing organic compounds "brown carbon" in the urban atmosphere. However, the atmospheric importance of these SOAs remains unclear due to limited information about their optical properties. In this study, the complex refractive index (RI, m=n − ki) values at 405, 532, and 781 nm of the SOAs generated during the photooxidation of toluene (toluene-SOAs) under a variety of initial nitrogen oxide (NOx= NO + NO2) conditions were examined by photoacoustic spectroscopy (PAS) and cavity ring down spectroscopy (CRDS). The complex RI values obtained in the present study and reported in the literature indicate that the k value, which represents the light absorption of the toluene-SOAs steeply increased to shorter wavelengths at <405 nm, while the n value gradually increased to shorter wavelengths from 781 to 355 nm. The k values at 405 nm were found to increase from 1.8 × 10−3 to 7.2 × 10−3 with increasing initial NOx concentration from 109 to 571 ppbv. The nitrate to organics ratio of the SOAs determined using a highresolution time-of-flight aerosol mass spectrometer (H-ToF-AMS) also increased with increasing initial NOx concentration. The RI values of the SOAs generated during the photooxidation of 1,3,5-trimethylbenzene in the presence of NOx (1,3,5-TMB-SOAs) were also determined to investigate the influence of the chemical structure of the precursor on the optical properties of the SOAs, and it was found that the light absorption of the 1,3,5-TMB-SOAs is negligible at all of the wavelengths investigated (405, 532, and 781 nm). These results can be reasonably explained by the hypothesis that nitro-aromatic compounds such as nitro-cresols are the major contributors to the light absorption of the toluene-SOAs. Using the obtained RI values, mass absorption cross sections of the toluene-SOAs at 405 and 532 nm were estimated to be 0.08–0.48 and 0.002–0.081 m2 g−1, respectively, under typical conditions in an urban atmosphere during the daytime. These results indicate that light absorption by the SOAs potentially contributes to the radiation balance at ultraviolet wavelengths below ~400 nm, specifically when the mass concentrations of the anthropogenic SOAs are significant compared with those of black carbon particles.
Size distribution of atmospheric particulate mercury in marine and coastal atmospheres
Authors: Feddersen D. M. , Talbot R. , Mao H. , Sive B. C.
Published: June 2012

Abstract. A study was conducted to determine the size distribution of particulate mercury (HgP) at a marine and coastal site, and compare the seasonality at both sites. Data was collected during summer 2009 and 2010, winter 2010, and spring 2010. Two cascade impactors were used to collect HgP in ten size fractions ranging from >10 μm to <0.4 μm. During summer 2009, HgP was found mainly (50–60%) in coarse fractions, 1.1 to 5.8 μm, composed of sea salt particles at both our coastal site (Thompson Farm) and marine site (Appledore Island). In winter, HgP at Thompson Farm was dominated (65%) by fine particles, while in spring and summer 2010, at both sites, HgP was distributed across the coarse and fine fractions (40% each). Using bulk filters to collect total HgP during each campaign, we show a diurnal cycle that matches that of gaseous elemental mercury. Finally, dry deposition rates of HgP were calculated to be 1.7–2.8 ng m−2 day−1 in the summer, 4.6 ng m−2 day−1 in the winter, and 2.5 ng m−2 day−1 in the spring.
Impact of natural and anthropogenic aerosols on stratocumulus and precipitation in the Southeast Pacific: a regional modelling study using WRF-Chem
Authors: Yang Q. , Gustafson W. I. , Fast J. D. , Wang H. , Easter R. C. , Wang M. , Ghan S. J. , Berg L. K. , Leung L. R. , Morrison H.
Published: June 2012

Abstract. Cloud-system resolving simulations with the chemistry version of the Weather Research and Forecasting (WRF-Chem) model are used to quantify the relative impacts of regional anthropogenic and oceanic emissions on changes in aerosol properties, cloud macro- and microphysics, and cloud radiative forcing over the Southeast Pacific (SEP) during the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) (15 October–16 November 2008). Two distinct regions are identified. The near-coast polluted region is characterized by the strong suppression of non-sea-salt particle activation due to sea-salt particles, a dominant role of first over second indirect effects, low surface precipitation rates, and limited impact of aerosols associated with anthropogenic emissions on clouds. The effects of natural marine aerosols on cloud properties (e.g., cloud optical depth and cloud-top and cloud-base heights), precipitation, and the top of atmosphere and surface shortwave fluxes counteract those of anthropogenic aerosols over this region. The relatively clean remote region is characterized by large contributions of aerosols from non-local sources (lateral boundaries), much stronger drizzle at the surface, and high aerosol-cloud-precipitation interactions under a scenario of five-fold increase in anthropogenic emissions. Clouds in this clean region are quite sensitive (e.g., a 13% increase in cloud-top height and a 9% increase in surface albedo) to a moderate increase (25% of the reference case) in cloud condensation nuclei (CCN) concentration produced by a five-fold increase in regional anthropogenic emissions. The reduction of precipitation due to this increase in anthropogenic aerosols more than doubles the aerosol lifetime in the clean marine boundary layer. Therefore, the aerosol impacts on precipitation are amplified by the positive feedback of precipitation on aerosol, which ultimately alters the cloud micro- and macro-physical properties, leading to strong aerosol-cloud-precipitation interactions. The high sensitivity is also related to an increase in cloud-top entrainment rate (by 16% at night) due to the increased anthropogenic aerosols. The simulated aerosol-cloud-precipitation interactions due to the increased anthropogenic aerosols have a stronger diurnal cycle over the clean region compared to the near-coast region with stronger interactions at night. During the day, solar heating results in more frequent decoupling of the cloud and sub-cloud layers, thinner clouds, reduced precipitation, and reduced sensitivity to the increase in anthropogenic emissions. The results of this study imply that the energy balance perturbations from increased anthropogenic emissions are larger in the more susceptible clean environment than in already polluted environment and is larger than possible from first indirect effect alone.
Effect of photochemical aging on the ice nucleation properties of diesel and wood burning particles
Authors: Chou C. , Stetzer O. , Tritscher T. , Chirico R. , Heringa M. F. , Kanji Z. A. , Weingartner E. , Prévôt A. S. H. , Baltensperger U. , Lohmann U.
Published: June 2012

Abstract. A measurement campaign (IMBALANCE) was conducted in 2009 and aimed at characterizing the physical and chemical properties of freshly emitted and photochemically aged combustion particles emitted from a log wood burner and diesel vehicles: a EURO3 Opel Astra with a diesel oxidation catalyst (DOC) but no particle filter and a EURO2 Volkswagen Transporter TDI Syncro with no emission after-treatment. Ice nucleation experiments in the deposition and condensation freezing modes were conducted with the Portable Ice Nucleation Chamber (PINC) at three nominal temperatures, −30 °C, −35 °C and −40 °C. Freshly emitted diesel particles showed ice formation only at −40 °C in the deposition mode at 137% relative humidity with respect to ice (RHi) and 92% relative humidity with respect to water (RHw), and photochemical aging did not play a role in modifying their ice nucleation behavior. Only one diesel experiment where α-pinene was added, showed an ice nucleation enhancement after the aging at −35 °C. Wood burning particles also act as ice nuclei (IN) at −40 °C in the deposition mode at the same conditions as for diesel particles and photochemical aging did also not alter the ice formation properties of the wood burning particles. Unlike diesel particles, wood burning particles form ice via condensation freezing at −35 °C with no ice nucleation observed at −30 °C for wood burning particles. Photochemical aging did not affect the ice nucleation ability of the diesel and wood burning particles at the three different temperatures investigated but a broader range of temperatures below −30 °C need to be investigated in order to draw an overall conclusion on the effect of photochemical aging on deposition/condensation ice nucleation across the entire temperature range relevant to cold clouds.
On the scaling effect in global surface air temperature anomalies
Authors: Varotsos C. A. , Efstathiou M. N.
Published: June 2012

Abstract. The annual and the monthly mean values of the land-surface air temperature anomalies during 1880–2011, over both hemispheres, are used to investigate the existence of long-range correlations in their temporal march. The analytical tool employed is the detrended fluctuation analysis which eliminates the noise of the non-stationarities that characterize the land-surface air temperature anomalies in both hemispheres. The main result obtained is that deviations of one sign of the land-surface air temperature anomalies in both hemispheres are generally followed by deviations with the same sign at different time intervals. In other words the land-surface air temperature anomalies exhibit persistent behaviour i.e., deviations tend to keep the same sign. Specifically, the scaling exponents of the annual (monthly) mean land-surface air temperature anomalies, α = 0.65 (0.73–0.75), are roughly equal in both hemispheres approaching to that of the global annual (monthly) mean land-surface air temperature anomalies, α =0.68 (0.80). Taking into account our earlier study according to which the land and sea surface temperature anomalies obey scaling exponents α =0.78 and α = 0.89 in the Northern and Southern Hemisphere, respectively, we conclude that the difference between the scaling exponents in both sea and land contributions to the surface air temperature stems mainly from the sea surface temperature, which exhibits stronger memory in the Southern than in the Northern Hemisphere. This conclusion may be attributed to the fact that oceans have the greatest capacity to store heat, being thus able to regulate the temperature on land with less pronounced persistence. Moreover, the variability of the scaling-exponents of the annual mean values of the land-surface air temperature anomalies versus latitude shows an increasing trend from the low to polar regions starting from the classical random walk (white noise) over tropics. The gradual increase of the scaling exponent from the low to high latitudes (which is stronger over the Southern Hemisphere) could be associated with the poleward increase in climate sensitivity predicted by the global climate models. In this context, the persistence in the land-surface air temperature enhances the feasibility of its reliable long-term forecast, which is very important for various climate applications.
An integrated flask sample collection system for greenhouse gas measurements
Authors: Turnbull J. , Guenther D. , Karion A. , Sweeney C. , Anderson E. , Andrews A. , Kofler J. , Miles N. , Newberger T. , Richardson S. , Tans P.
Published: June 2012

Abstract. A one hour integrated flask sampling system to collect air in automated NOAA/ESRL 12-flask packages is described. The integrating compressor system uses a mass flow controller to regulate the flow of air through a 15 l volume, thus providing a mixture of air collected over an hour-long period. By beginning with a high flow rate of 3800 standard liters per minute and gradually decreasing the flow rate over time to 290 standard liters per minute it is possible to obtain a nearly uniformly time averaged sample of air and collect it into a pressurized 0.7 l flask. The weighting function determining the air mixture obtained is described in detail. Laboratory and field tests demonstrate that the integrated sample approximates a simple mean of air collected during the one-hour sampling time.
Volcanic synchronisation between the EPICA Dome C and Vostok ice cores (Antarctica) 0–145 kyr BP
Authors: Parrenin F. , Petit J.-R. , Masson-Delmotte V. , Wolff E. , Basile-Doelsch I. , Jouzel J. , Lipenkov V. , Rasmussen S. O. , Schwander J. , Severi M. , Udisti R. , Veres D. , Vinther B. M.
Published: June 2012

Abstract. This study aims at refining the synchronisation between the EPICA Dome C (EDC) and Vostok ice cores in the time interval 0–145 kyr BP by using the volcanic signatures. 102 common volcanic events were identified by using continuous electrical conductivity (ECM), di-electrical profiling (DEP) and sulfate measurements while trying to minimize the distortion of the glaciological chronologies. This is an update and a continuation of previous works performed over the 0–45 kyr interval that provided 56 tie points to the ice core chronologies (Udisti et al., 2004). This synchronisation will serve to establish Antarctic Ice Core Chronology 2012, the next synchronised Antarctic dating. A change of slope in the EDC-depth/Vostok-depth diagram is probably related to a change of accumulation regime as well as to a change of ice thickness upstream of the Lake Vostok, but we did not invoke any significant temporal change of surface accumulation at EDC relative to Vostok. No significant phase difference is detected between the EDC and Vostok isotopic records, but depth shifts between the Vostok 3G and 5G ice cores prevent from looking at this problem accurately. Three possible candidates for the Toba volcanic super-eruption ~73 kyr ago are suggested in the Vostok and EDC volcanic records. Neither the ECM, DEP nor the sulfate fingerprints for these 3 events are significantly larger than many others in the records.
Modeling the consequences on late Triassic environment of intense pulse-like degassing during the Central Atlantic Magmatic Province using the GEOCLIM model
Authors: Paris G. , Donnadieu Y. , Beaumont V. , Fluteau F. , Goddéris Y.
Published: June 2012

Abstract. The Triassic-Jurassic boundary (TJB) is associated with one of the five largest mass extinctions of the Phanerozoic. A deep carbon cycle perturbation and a carbonate production crisis are observed during the late Triassic. The Central Atlantic Magmatic Province (CAMP), one of the most important large igneous provinces of the Phanerozoic, emplaced at the TJB. To understand the carbon cycle perturbations observed at the TJB, we investigate the consequences of CO2 degassing associated to the CAMP emplacement on atmospheric and oceanic carbon cycle. The CO2 input within the atmosphere due to volcanism has been modeled using a global biogeochemical cycle box model (COMBINE) coupled with a climate model (FOAM). Weathering fluxes and CO2 equilibrium are constrained by the Rhaetian paleogeography and different scenarios of the CAMP emplacement are modeled. The study focuses (1) on the geological record and the carbonate productions crisis and (2) on the sedimentary carbon isotope record. For point (1), comparison of different modeling scenarios shows that a Gaussian CO2 emission distribution over the duration of the main activity phase of the CAMP fails in reproducing any of the geological observations, mainly the carbonate production crisis observed in the late Rhaetian sediments. Contrastingly, intense degassing peaks lead to successive decrease in carbonate production as observed in the geological record. For point (2), the perturbations of carbon cycle due to the degassing of CO2 with a mantellic carbon isotopic composition of −5‰ do not reproduce the intensity of the observed carbon isotope excursions. This was achieved in our model by assuming a mantellic carbon isotopic composition of −20‰. Even if this hypothesis requires further investigations, such low values may be associated to degassing of carbon from pools of light isotopic carbon located at the transition zone (Cartigny, 2010), possibly linked to setting of large igneous provinces (LIP's). Breakdown of biological primary productivity can also partially account for the sedimentary carbon isotope excursions and for the observed increase of atmospheric pCO2.
The problem of the second wind turbine – a note on a common but flawed wind power estimation method
Authors: Gans F. , Miller L. M. , Kleidon A.
Published: June 2012

Abstract. Several recent wind power estimates suggest that this renewable energy resource can meet all of the current and future global energy demand with little impact on the atmosphere. These estimates are calculated using observed wind speeds in combination with specifications of wind turbine size and density to quantify the extractable wind power. However, this approach neglects the effects of momentum extraction by the turbines on the atmospheric flow that would have effects outside the turbine wake. Here we show with a simple momentum balance model of the atmospheric boundary layer that this common methodology to derive wind power potentials requires unrealistically high increases in the generation of kinetic energy by the atmosphere. This increase by an order of magnitude is needed to ensure momentum conservation in the atmospheric boundary layer. In the context of this simple model, we then compare the effect of three different assumptions regarding the boundary conditions at the top of the boundary layer, with prescribed hub height velocity, momentum transport, or kinetic energy transfer into the boundary layer. We then use simulations with an atmospheric general circulation model that explicitly simulate generation of kinetic energy with momentum conservation. These simulations show that the assumption of prescribed momentum import into the atmospheric boundary layer yields the most realistic behavior of the simple model, while the assumption of prescribed hub height velocity can clearly be disregarded. We also show that the assumptions yield similar estimates for extracted wind power when less than 10% of the kinetic energy flux in the boundary layer is extracted by the turbines. We conclude that the common method significantly overestimates wind power potentials by an order of magnitude in the limit of high wind power extraction. Ultimately, environmental constraints set the upper limit on wind power potential at larger scales rather than detailed engineering specifications of wind turbine design and placement.
Performance of McRAS-AC in the GEOS-5 AGCM: aerosol-cloud-microphysics, precipitation, cloud radiative effects, and circulation
Authors: Sud Y. C. , Lee D. , Oreopoulos L. , Barahona D. , Nenes A. , Suarez M. J.
Published: June 2012

Abstract. A revised version of the Microphysics of clouds with Relaxed Arakawa-Schubert and Aerosol-Cloud interaction scheme (McRAS-AC) including, among others, the Barahona and Nenes ice nucleation parameterization, is implemented in the GEOS-5 AGCM. Various fields from a 10-yr long integration of the AGCM with McRAS-AC were compared with their counterparts from an integration of the baseline GEOS-5 AGCM using satellite data as observations. Generally McRAS-AC simulations have smaller biases in cloud fields and cloud radiative effects over most of the regions of the Earth than the baseline GEOS-5 AGCM. Two systematic biases are identified in the McRAS-AC runs: one under-prediction of cloud particles around 40° S–60° S, and one over-prediction of cloud water path during Northern Hemisphere summer over the Gulf Stream and North Pacific. Sensitivity analyses show that these biases potentially originate from biases in the aerosol input. The first bias is largely eliminated in a sensitivity test using 50% smaller sea-salt aerosol particles, while the second bias is much reduced when interactive aerosol chemistry was turned on. The main drawback of McRAS-AC is dearth of low-level marine stratus clouds, probably due to lack of boundary-layer clouds that is an outcome of explicit dry-convection not yet implemented into the cloud model. Nevertheless, McRAS-AC simulates realistic clouds and their optical properties that can further improve with better aerosol-input. Thereby, McRAS-AC has the potential to be a valuable tool for climate modeling research because of its superior simulation capabilities that physically couple aerosols, cloud microphysics, cloud macrophysics, and cloud-radiation interaction for all clouds.
Space-based passive microwave soil moisture retrievals and the correction for a dynamic open water fraction
Authors: Gouweleeuw B. T. , van Dijk A. I. J. M. , Guerschman J. P. , Dyce P. , Owe M.
Published: June 2012

Abstract. The large observation footprint of low-frequency satellite microwave emissions complicates the interpretation of near-surface soil moisture retrievals. While the effect of sub-footprint lateral heterogeneity is relatively limited under unsaturated conditions, open water bodies (if not accounted for) cause a strong positive bias in the satellite-derived soil moisture retrieval. This bias is generally assumed static and associated with large, continental lakes and coastal areas. Temporal changes in the extent of smaller water bodies as small as a few percent of the sensor footprint size, however, can cause significant and dynamic biases. We analysed the influence of such small open water bodies on near-surface soil moisture products derived from actual (non-synthetic) data from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) for three areas in Oklahoma, USA. Differences between on-ground observations, model estimates and AMSR-E retrievals were related to dynamic estimates of open water fraction, one retrieved from a global daily record based on higher frequency AMSR-E data, a second derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and a third through inversion of the radiative transfer model, used to retrieve soil moisture. The comparison demonstrates the presence of relatively small areas (<0.05) of open water in or near the sensor footprint, possibly in combination with increased, below-critical vegetation density conditions (optical density <0.8), which contribute to seasonally varying biases in excess of 0.2 (m3 m−3) soil water content. These errors need to be addressed, either through elimination or accurate characterisation, if the soil moisture retrievals are to be used effectively in a data assimilation scheme.
A study of the climate change impacts on fluvial flood propagation in the Vietnamese Mekong Delta
Authors: Dang Tri V. P. , Popescu I. , van Griensven A. , Solomatine D. , Trung N. H. , Green A.
Published: June 2012

Abstract. The present paper investigated what would be the flood propagation in the Vietnamese Mekong Delta (VMD), due to different projected climate change scenarios, if the 2000 flood event (the most recent highest flood in the history) was taken as a base for computation. The analysis herein was done to demonstrate the particular complexity of the flood dynamics. The future floods, on short term horizon, year 2050, were studied by considering the projected sea level rise (SLR) (+30 cm). At the same time, future flood hydrograph changes at Kratie, Cambodia were applied for the upstream boundary condition. In this study, the future flood hydrograph was separated into two scenarios in which: (i) Scenario 1 was projected in 2050 according to the adjusted regional climate model without any development in the Upper Mekong Basin; and, (ii) Scenario 2 was projected as in Scenario 1 but with the development of the Upper Mekong Basin after 2030. Analyses were done to identify the high sensitive areas in terms of flood conditions (i.e. with and without flood) according to the uncertainty of the projection of both the upstream and downstream boundary conditions. In addition, due to the rice-dominated culture in the VMD, possible impacts of flood on the rice-based farming systems were analysed.
New developments in the analysis of column-collapse pyroclastic density currents through numerical simulations of multiphase flows
Authors: Lepore S. , Scarpati C.
Published: June 2012

Abstract. A granular multiphase model has been used to evaluate the action of differently sized particles on the dynamics of fountains and associated pyroclastic density currents. The model takes into account the overall disequilibrium conditions between a gas phase and several solid phases, each characterized by its own physical properties. The dynamics of the granular flows (fountains and pyroclastic density currents) has been simulated by adopting a Reynolds-averaged Navier-Stokes model for describing the turbulence effects. Numerical simulations have been carried out by using different values for the eruptive column temperature at the vent, solid particle frictional concentration, turbulent kinetic energy, and dissipation. The results obtained provide evidence of the multiphase nature of the model and describe several disequilibrium effects. The low concentration (≤5 × 10−4) zones lie in the upper part of the granular flow, above the fountain, and above the tail and body of pyroclastic density current as thermal plumes. The high concentration zones, on the contrary, lie in the fountain and at the base of the current. Hence, pyroclastic density currents are assimilated to granular flows constituted by a low concentration suspension flowing above a high concentration basal layer (boundary layer), from the proximal regions to the distal ones. Interactions among the solid particles in the boundary layer of the granular flow are controlled by collisions between particles, whereas the dispersal of particles in the suspension is determined by the dragging of the gas phase. The simulations describe well the dynamics of a tractive boundary layer leading to the formation of stratified facies during Strombolian to Plinian eruptions.
Models of Affective Illness: Chronic Mild Stress in the Rat
Authors: Papp Mariusz
Published: June 2012

Described in this unit is a chronic mild stress (CMS) procedure used for predicting an antidepressant response. Following exposure to a variety of mild stressors for a period of several weeks, rat behavior is modified in a number of ways. Among these is a substantial reduction in consumption of a 1% sucrose solution. Chronic administration of antidepressant drugs reverses diminished enthusiasm for sucrose in these subjects. While most antidepressants must be administered for at least 3 to 5 weeks to normalize behavior, there are treatments that display a more rapid onset of action. More recently, it has been shown that the CMS‐induced deficit in sucrose consumption can also be reversed by second‐generation antipsychotics. Based on these findings, the CMS model can be employed in discovery programs aimed at identifying antianhedonic drugs (e.g., antidepressants and antipsychotics) that act more quickly than existing agents. Curr. Protoc. Pharmacol. 57:5.9.1‐5.9.11. © 2012 by John Wiley & Sons, Inc.
Whole‐Cell Configuration of the Patch‐Clamp Technique in the hERG Channel Assay to Predict the Ability of a Compound to Prolong QT Interval
Authors: Goineau Sonia , Legrand Christophe , Froget Guillaume
Published: June 2012

In vitro electrophysiological safety studies have become an integral part of the drug development process since, in many instances, compound‐induced QT prolongation has been associated with a direct block of human ether‐a‐go‐go‐related gene (hERG) potassium channels or its native current, the rapidly activating delayed rectifier potassium current (IKr). Therefore, the in vitro hERG channel patch‐clamp assay is commonly used as an early screen to predict the ability of a compound to prolong QT interval. The protocol described in this unit is designed to assess the effects of new chemical entities after acute or long‐term exposure on the amplitude of IKr in human embryonic kidney 293 (HEK293) cells stably transfected with the hERG channel (whole‐cell configuration of the patch‐clamp technique). Examples of results obtained with terfenadine, arsenic, pentamidine, erythromycin, and sotalol are provided for illustrative purposes. Curr. Protoc. Pharmacol. 57:10.15.1‐10.15.14. © 2012 by John Wiley & Sons, Inc.