bluuebunny/crossref_metadata_2025 huggingface dataset:
D'un drapeau l'autre. Jean Zay (1914-1940)
Authors: Loubes Olivier
Published: July 2010

D'un drapeau l'autre. Jean Zay (1914-1940), Olivier Loubes.

Élève à Orléans durant la Grande Guerre, puis ministre de l'Éducation nationale du Front populaire à la veille du second conflit mondial, Jean Zay, né en 1904, représente cette génération française grandie dans la culture de guerre, qui connut, à partir des années 1930, la culture de guerre civile autour des remises en question de la République parlementaire dont il était un des plus précoces et brillants exemples. Ici, son parcours, de sa copie du certificat d'études à son emprisonnement par Vichy, suite logique des attaques antisémites de l'avant-guerre, est lu à travers les cristallisations que le thème du drapeau a suscitées dans l'imaginaire politique français. Il montre que pour l'école, le drapeau devient l'image de la patrie en Paix, signe de l'abandon de l'enseignement de guerre. Dans la culture politique, il reste un symbole sacré, propice aux exploitations partisanes de la culture de guerre civile, dont Jean Zay fut la victime.
Comment l'enseigner ?
Authors: Borne Dominique
Published: July 2010

Comment l'enseigner ?, Dominique Borne.

L'histoire de l'Europe ne doit être pensée ni en fonction d'un destin inéluctable ni d'une géographie fixe. Il s'agit d'envisager autrement les histoires nationales en les mesurant et les critiquant à l'aune de l'Europe, en cessant de les dire incomparables. Les principes programmatiques à l'avenir devraient être le mixage des territoires-temps, l'examen des vrais lieux de mémoire, l'étude du choc des nations et des empires, celle des peuples sans nation, des réseaux des élites et de l'urbanité. Tout passe par une reconnaissance de l'altérité et de la pluralité.
Le musée, source ou moteur de recherche ?
Authors: Gervereau Laurent
Published: July 2010

Le musée, source ou moteur de recherche ?, Laurent Gervereau.

La rencontre entre musées et historiens est inévitable et nécessaire. Mais il reste à dessiner de vrais objets de recherches, à affiner les méthodes et à sortir des sentiers battus. En clair : il faut cesser d'instrumentaliser l'image, pour mieux en faire une source singulière, majeure et irremplaçable de l'histoire contemporaine.
Synthesis, electronic properties and self-assembly on Au{111} of thiolated (oligo)phenothiazines
Authors: Franz Adam W , Stoycheva Svetlana , Himmelhaus Michael , Müller Thomas J J
Published: July 2010

(Oligo)phenothiazinyl thioacetates, synthesized by a one-pot sequence, are electrochemically oxidizable and highly fluorescent. SAMs can be readily formed from thiols prepared by in situ deprotection of the thioacetates in the presence of a gold-coated silicon wafer. Monolayer formation is confirmed by ellipsometry and the results compared to those obtained by force field and DFT calculations.
Treatment Approaches to Juvenile Dermatomyositis (JDM) Across North America: The Childhood Arthritis and Rheumatology Research Alliance (CARRA) JDM Treatment Survey
Authors: STRINGER ELIZABETH , BOHNSACK JOHN , BOWYER SUZANNE L. , GRIFFIN THOMAS A. , HUBER ADAM M. , LANG BIANCA , LINDSLEY CAROL B. , OTA SYLVIA , PILKINGTON CLARISSA , REED ANN M. , SCUCCIMARRI ROSIE , FELDMAN BRIAN M.
Published: July 2010

Objective.

There are a number of different approaches to the initial treatment of juvenile dermatomyositis (JDM). We assessed the therapeutic approaches of North American pediatric rheumatologists to inform future studies of therapy in JDM.

Methods.

A survey describing clinical cases of JDM was sent to pediatric rheumatologists. The cases described children with varying severity of typical disease, disease with atypical features, or refractory disease. Three open-ended questions were asked following each case: (1) What additional investigations would you order; (2) What medicine(s) would you start (dose, route, frequency, adjustment over time); and (3) What nonmedication treatment(s) would you start.

Results.

The response rate was 84% (141/167). For typical cases of JDM, regardless of severity, almost all respondents used corticosteroids and another medication, methotrexate (MTX) being the most commonly used. The route and pattern of corticosteroid administration was variable. Intravenous immunoglobulin (IVIG) was used more frequently for more severe disease, for refractory disease, and for prominent cutaneous disease. Hydroxychloroquine was often used in milder cases and cases principally characterized by rash. Cyclophosphamide was reserved for ulcerative disease and JDM complicated by lung disease.

Conclusion.

For the majority of North American pediatric rheumatologists, corticosteroids and MTX appear to be the standard of care for typical cases of JDM. There is variability, however, in the route of administration of corticosteroids and use of IVIG and hydroxychloroquine.
An Internet-based Self-management Program with Telephone Support for Adolescents with Arthritis: A Pilot Randomized Controlled Trial
Authors: STINSON JENNIFER N. , McGRATH PATRICK J. , HODNETT ELLEN D. , FELDMAN BRIAN M. , DUFFY CIARAN M. , HUBER ADAM M. , TUCKER LORI B. , HETHERINGTON C. ROSS , TSE SHIRLEY M.L. , SPIEGEL LYNN R. , CAMPILLO SARAH , GILL NAVREET K. , WHITE MEGHAN E.
Published: July 2010

Objective.

To determine the feasibility of a 12-week Internet-based self-management program of disease-specific information, self-management strategies, and social support with telephone support for youth with juvenile idiopathic arthritis (JIA) and their parents, aimed at reducing physical and emotional symptoms and improving health-related quality of life (HRQOL).

Methods.

A nonblind pilot randomized controlled trial (NCT01011179) was conducted to test the feasibility of the “Teens Taking Charge: Managing Arthritis Online” Internet intervention across 4 tertiary-level centers in Canada. Participants were 46 adolescents with JIA, ages 12 to 18 years, and 1 parent for each participant, who were randomized to the control arm (n = 24) or the Internet intervention (n = 22).

Results.

The 2 groups were comparable on demographic and disease-related variables and treatment expectation at baseline. Attrition rates were 18.1% and 20.8%, respectively, from experimental and control groups. Ninety-one percent of participants randomized to the experimental group completed all 12 online modules and weekly phone calls with a coach in an average of 14.7 weeks (SD 2.1). The control group completed 90% of weekly attention-control phone calls. The Internet treatment was rated as acceptable by all youth and their parents. In posttreatment the experimental group had significantly higher knowledge (p < 0.001, effect size 1.32) and lower average weekly pain intensity (p = 0.03, effect size 0.78). There were no significant group differences in HRQOL, self-efficacy, adherence, and stress posttreatment.

Conclusion.

Findings support the feasibility (acceptability, compliance, and user satisfaction) and initial efficacy of Internet delivery of a self-management program for improving disease-specific knowledge and reducing pain in youth with JIA.
Productivity Loss Due to Presenteeism Among Patients with Arthritis: Estimates from 4 Instruments
Authors: ZHANG WEI , GIGNAC MONIQUE A.M. , BEATON DORCAS , TANG KENNETH , ANIS ASLAM H.
Published: July 2010

Objective.

To estimate and compare lost work hours attributable to presenteeism, defined as reduced productivity while working, in individuals with osteoarthritis (OA) or rheumatoid arthritis (RA), according to 4 instruments.

Methods.

In our prospective study, 250 workers with OA (n = 130) or RA (n = 120) were recruited from community and clinical sites. Lost hours due to presenteeism at baseline were estimated using the Health and Labor Questionnaire (HLQ), the Work Limitations Questionnaire (WLQ), the World Health Organization’s Health and Work Performance Questionnaire (HPQ), and the Work Productivity and Activity Impairment Questionnaire (WPAI). Only those respondents working over the past 2 weeks were included. Repeated-measures ANOVA was used to compare the lost-time estimates, according to each instrument.

Results.

Of the 212 respondents included in the analyses, the frequency of missing and “0” values among the instruments was different (17% and 61% for HLQ, 8% and 5% for WLQ, 1% and 16% for HPQ, 0% and 27% for WPAI, respectively). The average numbers of lost hours (SD) per 2 weeks due to presenteeism using HLQ, WLQ, HPQ, and WPAI were 1.6 (3.9), 4.0 (3.9), 13.5 (12.5), and 14.2 (16.7). The corresponding costs for the 2-week period were CAN$30.03, $83.05, $284.07, and $285.10. The differences in the lost-hour estimates according to instruments were significant (p < 0.001).

Conclusion.

Among individuals with arthritis, estimates of productivity losses while working vary widely according to the instruments chosen. Further research on instrument design and implications for a standardized approach to estimate lost time due to presenteeism is needed.
Dendritic Cell Apoptosis: Regulation of Tolerance versus Immunity
Authors: Kushwah Rahul , Hu Jim
Published: July 2010

Dendritic cell (DC) apoptosis is an important event that regulates the balance between tolerance and immunity through multiple pathways, and defects in DC apoptosis can trigger autoimmunity. DC apoptosis is also associated with immunosuppression and has been observed under several pathologies and infections. Recent studies indicate that apoptotic DCs can also play an active role in induction of tolerance. This review discusses the regulatory pathways of DC apoptosis, stimuli inducing DC apoptosis, and the implications of DC apoptosis in the induction of immunosuppression and/or tolerance.
Anti-TNF Therapy, from Rationale to Standard of Care: What Lessons Has It Taught Us?
Authors: Feldmann Marc , Maini Ravinder N.
Published: July 2010

In the mid-1980s, new molecular tools enabled the biology of cytokine expression and regulation to be studied. Our group uncovered a TNF-dependent cascade in active rheumatoid synovium, suggesting that TNF might be a therapeutic target; this concept was supported in an animal model of the disease. The proof of concept was a series of clinical trials, which have led to marked changes in the therapy of human rheumatoid arthritis and subsequently of other diseases. The work with TNF clearly demonstrated the importance of cytokines in medicine as well as the capacity of mAbs (or receptor fusion proteins) to be used long-term in large populations, thus changing the therapeutic landscape.
Aerosol optical properties and radiative forcing in the high Himalaya based on measurements at the Nepal Climate Observatory-Pyramid site (5079 m a.s.l.)
Authors: Marcq S. , Laj P. , Roger J. C. , Villani P. , Sellegri K. , Bonasoni P. , Marinoni A. , Cristofanelli P. , Verza G. P. , Bergin M.
Published: July 2010

Abstract. Intense anthropogenic emissions over the Indian sub-continent lead to the formation of layers of particulate pollution that can be transported to the high altitude regions of the Himalaya-Hindu-Kush (HKH). Aerosol particles contain a substantial fraction of strongly absorbing material, including black carbon (BC), organic compounds (OC), and dust all of which can contribute to atmospheric warming, in addition to greenhouse gases. Using a 3-year record of continuous measurements of aerosol optical properties, we present a time series of key climate relevant aerosol properties including the aerosol absorption (σap) and scattering (σsp) coefficients as well as the single-scattering albedo (w0). Results of this investigation show substantial seasonal variability of these properties, with long range transport during the pre- and post-monsoon seasons and efficient precipitation scavenging of aerosol particles during the monsoon season. The monthly averaged scattering coefficients range from 0.1 Mm−1 (monsoon) to 20 Mm−1 while the average absorption coefficients range from 0.5 Mm−1 to 3.5 Mm−1. Both have their maximum values during the pre-monsoon period (April) and reach a minimum during Monsoon (July–August). This leads to dry w0 values from 0.86 (pre-monsoon) to 0.79 (monsoon) seasons. Significant diurnal variability due to valley wind circulation is also reported. Using aerosol optical depth (AOD) measurements, we calculated the resulting direct local radiative forcing due to aerosols for selected air mass cases. We found that the presence of absorbing particulate material can locally induce an additional top of the atmosphere (TOA) forcing of 10 to 20 W m−2 for the first atmospheric layer (500 m above surface). The TOA positive forcing depends on the presence of snow at the surface, and takes place preferentially during episodes of regional pollution occurring on a very regular basis in the Himalayan valleys. Warming of the first atmospheric layer is paralleled by a substantial decrease of the amount of radiation reaching the surface. The surface forcing is estimated to range from −4 to −20 W m−2 for small-scale regional pollution events and large-scale pollution events, respectively. The calculated surface forcing is also very dependent on surface albedo, with maximum values occurring over a snow-covered surface. Overall, this work presents the first estimates of aerosol direct radiative forcing over the high Himalaya based on in-situ aerosol measurements, and results suggest a TOA forcing significantly greater than the IPCC reported values for green house gases.
Remote sensing of the tropical rain forest boundary layer using pulsed Doppler lidar
Authors: Pearson G. , Davies F. , Collier C.
Published: July 2010

Abstract. Within the framework of the Natural Environment Research Council (NERC) Oxidant and Particle Photochemical Processes (OP3) project, a pulsed Doppler lidar was deployed for a 3 month period in the tropical rain forest of Borneo to remotely monitor vertical and horizontal transport, aerosol distributions and clouds in the lower levels of the atmosphere. The Doppler velocity measurements reported here directly observe the mixing process and it is suggested that this is the most appropriate methodology to use in analysing the dispersion of canopy sourced species into the lower atmosphere. These data are presented with a view to elucidating the scales and structures of the transport processes, which effect the chemical and particulate concentrations in and above the forest canopy, for applications in the parameterisation of climate models.
Variation of ambient non-methane hydrocarbons in Beijing city in summer 2008
Authors: Wang B. , Shao M. , Lu S. H. , Yuan B. , Zhao Y. , Wang M. , Zhang S. Q. , Wu D.
Published: July 2010

Abstract. In conjunction with hosting the 2008 Beijing Olympics, the municipal government implemented a series of stringent air quality control measures. To assess the impacts on variation of ambient non-methane hydrocarbons (NMHCs), the whole air was sampled by canisters at one urban site and two suburban sites in Beijing, and 55 NMHC species were quantified by gas chromatography equipped with a quadrupole mass spectrometer and a flame ionization detector (GC/MSD/FID) as parts of the field Campaign for the Beijing Olympic Games Air Quality program (CareBeijing). According to the control measures, the data were presented according to four periods: 18–30 June, 8–19 July, 15–24 August (during the Olympic Games), and 6–15 September (during the Paralympic Games). Compared with the levels in June, the mixing ratios of NMHCs obtained in the Olympic and Paralympic Games periods were reduced by 35% and 25%, respectively. Source contributions were calculated using a chemical mass balance model (CMB 8.2). After implementing the control measures, emissions from target sources were obviously reduced, and reductions in vehicle exhaust could explain 48–82% of the reductions of ambient NMHCs. Reductions in emissions from gasoline evaporation, paint and solvent use, and the chemical industry contributed 9–40%, 3–24%, and 1–5%, respectively, to reductions of ambient NMHCs. Sources of liquefied petroleum gas (LPG) and biogenic emissions were not controlled, and contributions from these sources from July to September were stable or even higher than in June. Ozone formation potentials (OFPs) were calculated for the measured NMHCs. The total OFPs during the Olympic and Paralympic Games were reduced by 48% and 32%, respectively, compared with values in June. Reductions in the OFPs of alkenes and aromatics explained 77–92% of total OFP reductions. The alkenes and aromatics were mainly from vehicle exhausts, and reductions of vehicle exhaust gases explained 67–87% of reductions in alkenes and 38–80% of reductions in aromatics. These findings demonstrate the effectiveness of the air quality control measures enacted for the 2008 Olympics and indicate that controlling vehicular emissions could be the most important measure to improve air quality in Beijing.
Optical, physical and chemical characteristics of Australian continental aerosols: results from a field experiment
Authors: Radhi M. , Box M. A. , Box G. P. , Mitchell R. M. , Cohen D. D. , Stelcer E. , Keywood M. D.
Published: July 2010

Abstract. Mineral dust is one of the major components of the world's aerosol mix, having a number of impacts within the Earth system. However, the climate forcing impact of mineral dust is currently poorly constrained, with even its sign uncertain. As Australian deserts are more reddish than those in the Northern Hemisphere, it is important to better understand the physical, chemical and optical properties of this important aerosol. We have investigated the properties of Australian desert dust at a site in SW Queensland, which is strongly influenced by both dust and biomass burning aerosol. Three years of ground-based monitoring of spectral optical thickness has provided a statistical picture of gross aerosol properties. The aerosol optical depth data showed a clear though moderate seasonal cycle with an annual mean of 0.06 ± 0.03. The Angstrom coefficient showed a stronger cycle, indicating the influence of the winter-spring burning season in Australia's north. AERONET size distributions showed a generally bimodal character, with the coarse mode assumed to be mineral dust, and the fine mode a mixture of fine dust, biomass burning and marine biogenic material. In November 2006 we undertook a field campaign which collected 4 sets of size-resolved aerosol samples for laboratory analysis – ion beam analysis and ion chromatography. Ion beam analysis was used to determine the elemental composition of all filter samples, although elemental ratios were considered the most reliable output. Scatter plots showed that Fe, Al and Ti were well correlated with Si, and Co reasonably well correlated with Si, with the Fe/Al ratio somewhat higher than values reported from Northern Hemisphere sites (as expected). Scatter plots for Ca, Mn and K against Si showed clear evidence of a second population, which in some cases could be identified with a particular sample day or size fraction. These data may be used to attempt to build a signature of soil in this region of the Australian interior. Ion chromatography was used to quantify water soluble ions for 2 of our sample sets, complementing the picture provided by ion beam analysis. The strong similarities between the MSA and SO42− size distributions argue strongly for a marine origin of much of the SO42−. The similarity of the Na+, Cl− and Mg2+ size distributions also argue for a marine contribution. Further, we believe that both NO3− and NH4+ are the result of surface reactions with appropriate gases.
Water-Soluble Organic Aerosol material and the light-absorption characteristics of aqueous extracts measured over the Southeastern United States
Authors: Hecobian A. , Zhang X. , Zheng M. , Frank N. , Edgerton E. S. , Weber R. J.
Published: July 2010

Abstract. Light absorption of fine particle (PM2.5) aqueous extracts between wavelengths of 200 and 800 nm were investigated from two data sets: 24-h Federal Reference Method (FRM) filter extracts from 15 Southeastern US monitoring sites over the year of 2007 (900 filters), and online measurements from a Particle-Into-Liquid Sampler deployed from July to mid-August 2009 in Atlanta, Georgia. Three main sources of soluble chromophores were identified: biomass burning, mobile source emissions, and compounds linked to secondary organic aerosol (SOA) formation. Absorption spectra of aerosol solutions from filter extracts were similar for different sources. Angstrom exponents were ~7±1 for biomass burning and non-biomass burning-impacted 24-h filter samples (delineated by a levoglucosan concentration of 50 ng m−3) at both rural and urban sites. The absorption coefficient from measurements averaged between wavelength 360 and 370 nm (Abs365, in units m−1) was used as a measure of overall brown carbon light absorption. Biomass-burning-impacted samples were highest during winter months and Abs365 was correlated with levoglucosan at all sites. During periods of little biomass burning in summer, light absorbing compounds were still ubiquitous and correlated with fine particle Water-Soluble Organic Carbon (WSOC), but comprised a much smaller fraction of the WSOC, where Abs365/WSOC (i.e., mass absorption efficiency) was typically ~3 times higher in biomass burning-impacted samples. Factor analysis attributed 50% of the yearly average Abs365 to biomass burning sources. Brown carbon from primary urban emissions (mobile sources) was also observed and accounted for ~10% of the regional yearly average Abs365. Summertime diurnal profiles of Abs365 and WSOC showed that morning to midday increases in WSOC from photochemical production were associated with a decrease in Abs365/WSOC. After noon, this ratio substantially increased, indicating that either some fraction of the non-light absorbing fresh SOA was rapidly (within hours) converted to chromophores heterogeneously, or that SOA from gas-particle partitioning later in the day was more light-absorbing. Factor analysis on the 24-h integrated filter data associated ~20 to 30% of Abs365 over 2007 with a secondary source that was highest in summer and also the main source for oxalate, suggesting that aqueous phase reactions may account for the light-absorbing fraction of WSOC observed throughout the Southeastern US in summer.
Atmospheric nucleation: highlights of the EUCAARI project and future directions
Authors: Kerminen V.-M. , Petäjä T. , Manninen H. E. , Paasonen P. , Nieminen T. , Sipilä M. , Junninen H. , Ehn M. , Gagné S. , Laakso L. , Riipinen I. , Vehkamäki H. , Kurten T. , Ortega I. K. , Dal Maso M. , Brus D. , Hyvärinen A. , Lihavainen H. , Leppä J. , Lehtinen K. E. J. , Mirme A. , Mirme S. , Hõrrak U. , Berndt T. , Stratmann F. , Birmili W. , Wiedensohler A. , Metzger A. , Dommen J. , Baltensperger U. , Kiendler-Scharr A. , Mentel T. F. , Wildt J. , Winkler P. M. , Wagner P. E. , Petzold A. , Minikin A. , Plass-Dülmer C. , Pöschl U. , Laaksonen A. , Kulmala M.
Published: July 2010

Abstract. Within the project EUCAARI (European Integrated project on Aerosol Cloud Climate and Air Quality interactions), atmospheric nucleation was studied by (i) developing and testing new air ion and cluster spectrometers, (ii) conducting homogeneous nucleation experiments for sulphate and organic systems in the laboratory, (iii) investigating atmospheric nucleation mechanism under field conditions, and (iv) applying new theoretical and modelling tools for data interpretation and development of parameterisations. The current paper provides a synthesis of the obtained results and identifies the remaining major knowledge gaps related to atmospheric nucleation. The most important technical achievement of the project was the development of new instruments for measuring sub-3 nm particle populations, along with the extensive application of these instruments in both the laboratory and the field. All the results obtained during EUCAARI indicate that sulphuric acid plays a central role in atmospheric nucleation, in addition to which other vapours, especially organic ones, are needed to explain the nucleation and the subsequent growth processes. Both our field and laboratory data demonstrate that the nucleation rate scales to the first or second power of the nucleating vapour concentration(s). This agrees with the few earlier field observations, but is in stark contrast with classical thermodynamic nucleation theories. The average formation rates of 2-nm particles were found to vary by almost two orders of magnitude between the different EUCAARI sites, whereas the formation rates of charged 2-nm particles varied very little between the sites. Overall, our observations are indicative of frequent, yet moderate, ion-induced nucleation usually outweighed by much stronger neutral nucleation events in the lower troposphere. The most concrete outcome of the EUCAARI nucleation studies are the new semi-empirical nucleation rate parameterizations based on field observations, along with updated aerosol formation parameterizations.
Improved global modelling of HOx recycling in isoprene oxidation: evaluation against the GABRIEL and INTEX-A aircraft campaign measurements
Authors: Stavrakou T. , Peeters J. , Müller J.-F.
Published: July 2010

Abstract. Stimulated by recent important developments regarding the oxidation chemistry of isoprene, this study evaluates and quantifies the impacts of different mechanism updates on the boundary layer concentrations of OH and HO2 radicals using the IMAGESv2 global chemistry transport model. The model results for HOx, isoprene, NO, and ozone are validated against air-based observations from the GABRIEL campaign, conducted over the Guyanas in October 2005, and from the INTEX-A campaign over the Eastern US in summer 2004. The version 2 of the Mainz Isoprene Mechanism (MIM2, Taraborrelli et al., 2009) used as reference mechanism in our simulations, has been modified to test (i) the artificial OH recycling proposed by Lelieveld et al. (2008), (ii) the epoxide formation mechanism proposed by Paulot et al. (2009b), and finally (iii) the HOx regeneration of the Leuven Isoprene Mechanism (LIM0) proposed by Peeters et al. (2009); Peeters and Müller (2010). The simulations show that the LIM0 scheme holds by far the largest potential impact on HOx concentrations over densely vegetated areas in the Tropics as well as at mid-latitudes. Strong increases, by up to a factor of 4 in the modelled OH concentrations, and by a factor of 2.5–3 in the HO2 abundances are estimated through the LIM0 mechanism compared to the traditional isoprene degradation schemes. Comparatively much smaller OH increases (<25%) are associated with the implementation of the mechanism of Paulot et al. (2009b); moreover, the global production of epoxides is strongly suppressed (by a factor of 4) when the LIM0 scheme is combined with this mechanism. Hydroxyperoxy-aldehydes (HPALDs) are found to be major first-generation products in the oxidation of isoprene by OH, with a combined globally averaged yield of 50–60%. The use of the LIM0 chemistry in the global model allows for reconciling the model with the observed concentrations at a satisfactory level, compared to the other tested mechanisms, as the observed averaged mixing ratios of both OH and HO2 in the boundary layer can be reproduced to within 30%. In spite of the remaining uncertainties in the theoretically-predicted rates of critical radical reactions leading to the formation of HPALDs, and even more in the subsequent degradation of these new compounds, the current findings make a strong case for the newly proposed chemical scheme.
The vorticity budget of developing Typhoon Nuri (2008)
Authors: Raymond D. J. , López Carrillo C.
Published: July 2010

Abstract. The formation of west Pacific tropical cyclone Nuri (2008) was observed over four days from easterly wave to typhoon stage by aircraft using scanning Doppler radar and dropsonde data. This typhoon intensified rapidly in a significantly sheared environment. In spite of the shear, overlapping closed circulations existed in the storm frame of reference in the boundary layer and at 5 km elevation, providing a deep region protected from environmental influences. The vorticity budget was analyzed and it was found that vorticity convergence dominated vortex tilting on the storm scale in the lower troposphere. At times vorticity convergence also greatly exceeded frictional spindown in the boundary layer. Thus, the Ekman pumping hypothesis was found to be a poor approximation in the early stages of the development of this typhoon. As Nuri developed, convective sources of boundary layer vorticity became fewer but more intense, culminating in a single nascent eyewall at the tropical storm stage. A non-developing tropical wave case was also analyzed. This system started with much weaker circulations in the boundary layer and aloft, leaving it unprotected against environmental intrusion. This may explain its failure to develop.
Seasonal and local time variability of ripples from airglow imager observations in US and Japan
Authors: Yue J. , Nakamura T. , She C.-Y. , Weber M. , Lyons W. , Li T.
Published: July 2010

Abstract. Ripples as seen in airglow imagers are small wavy structures with short horizontal wavelengths (<15 km). Ripples are thought to form as the result of local instabilities, which are believed to occur when the amplitude of gravity waves becomes large enough. We have investigated ripple formation based on years of airglow imager observations located at Fort Collins, Colorado (41° N, 105° W) and Misato Observatory, Japan (34° N, 135° E)/Shigaraki MU Observatory (35° N, 136° E). Na temperature-wind lidar observations are employed to detect convective and dynamic instabilities in the mesosphere and lower thermosphere (MLT) region over Fort Collins, Colorado. Seasonal variation of the ripple occurrence in Colorado is compared to that of the lidar-measured instability. The occurrence frequency of ripples varies semiannually, with maxima occurring during solstices and minima during equinoxes in both Colorado and Japan. However, the probability of convective and dynamic instabilities varies annually with a peak in Colorado winter. The seasonal variation of the occurrence frequency of ripples correlates with that of the gravity wave variances in the MLT. Ripple occurrence over Colorado also shows strong local time dependence, but it bears little resemblance to the local time dependence of instability probability.
Areal rainfall estimation using moving cars as rain gauges – a modelling study
Authors: Haberlandt U. , Sester M.
Published: July 2010

Abstract. Optimal spatial assessment of short-time step precipitation for hydrological modelling is still an important research question considering the poor observation networks for high time resolution data. The main objective of this paper is to present a new approach for rainfall observation. The idea is to consider motorcars as moving rain gauges with windscreen wipers as sensors to detect precipitation. This idea is easily technically feasible if the cars are provided with GPS and a small memory chip for recording the coordinates, car speed and wiper frequency. This study explores theoretically the benefits of such an approach. For that a valid relationship between wiper speed and rainfall rate considering uncertainty was assumed here. A simple traffic model is applied to generate motorcars on roads in a river basin. Radar data are used as reference rainfall fields. Rainfall from these fields is sampled with a conventional rain gauge network and with several dynamic networks consisting of moving motorcars, using different assumptions such as accuracy levels for measurements and sensor equipment rates for the car networks. Those observed point rainfall data from the different networks are then used to calculate areal rainfall for different scales. Ordinary kriging and indicator kriging are applied for interpolation of the point data with the latter considering uncertain rainfall observation by cars e.g. according to a discrete number of windscreen wiper operation classes. The results are compared with the values from the radar observations. The study is carried out for the 3300 km2 Bode river basin located in the Harz Mountains in Northern Germany. The results show, that the idea is theoretically feasible and motivate practical experiments. Only a small portion of the cars needed to be equipped with sensors for sufficient areal rainfall estimation. Regarding the required sensitivity of the potential rain sensors in cars it could be shown, that often a few classes for rainfall observation are enough for satisfactory areal rainfall estimation. The findings of the study suggest also a revisiting of the rain gauge network optimisation problem.
On the uncertainty of stream networks derived from elevation data: the error propagation approach
Authors: Hengl T. , Heuvelink G. B. M. , van Loon E. E.
Published: July 2010

Abstract. DEM error propagation methodology is extended to the derivation of vector-based objects (stream networks) using geostatistical simulations. First, point sampled elevations are used to fit a variogram model. Next 100 DEM realizations are generated using conditional sequential Gaussian simulation; the stream network map is extracted for each of these realizations, and the collection of stream networks is analyzed to quantify the error propagation. At each grid cell, the probability of the occurrence of a stream and the propagated error are estimated. The method is illustrated using two small data sets: Baranja hill (30 m grid cell size; 16 512 pixels; 6367 sampled elevations), and Zlatibor (30 m grid cell size; 15 000 pixels; 2051 sampled elevations). All computations are run in the open source software for statistical computing R: package geoR is used to fit variogram; package gstat is used to run sequential Gaussian simulation; streams are extracted using the open source GIS SAGA via the RSAGA library. The resulting stream error map (Information entropy of a Bernoulli trial) clearly depicts areas where the extracted stream network is least precise – usually areas of low local relief and slightly convex (0–10 difference from the mean value). In both cases, significant parts of the study area (17.3% for Baranja Hill; 6.2% for Zlatibor) show high error (H>0.5) of locating streams. By correlating the propagated uncertainty of the derived stream network with various land surface parameters sampling of height measurements can be optimized so that delineated streams satisfy the required accuracy level. Such error propagation tool should become a standard functionality in any modern GIS. Remaining issue to be tackled is the computational burden of geostatistical simulations: this framework is at the moment limited to small data sets with several hundreds of points. Scripts and data sets used in this article are available on-line via the www.geomorphometry.org website and can be easily adopted/adjusted to any similar case study.
Effect of the spatial distribution of physical aquifer properties on modelled water table depth and stream discharge in a headwater catchment
Authors: Gascuel-Odoux C. , Weiler M. , Molenat J.
Published: July 2010

Abstract. Water table depth and its dynamics on hillslopes are often poorly predicted despite they control both water transit time within the catchment and solute fluxes at the catchment outlet. This paper analyses how relaxing the assumption of lateral homogeneity of physical properties can improve simulations of water table depth and dynamics. Four different spatial models relating hydraulic conductivity to topography have been tested: a simple linear relationship, a linear relationship with two different topographic indexes, two Ks domains with a transitional area. The Hill-Vi model has been modified to test these hypotheses. The studied catchment (Kervidy-Naizin, Western France) is underlain by schist crystalline bedrock. A shallow and perennial groundwater highly reactive to rainfall events mainly develops in the weathered saprolite layer. The results indicate that (1) discharge and the water table in the riparian zone are similarly predicted by the four models, (2) distinguishing two Ks domains constitutes the best model and slightly improves prediction of the water table upslope, and (3) including spatial variations in the other parameters such as porosity or rate of hydraulic conductivity decrease with depth does not improve the results. These results underline the necessity of better investigations of upslope areas in hillslope hydrology.
Hydrological characterization of watersheds in the Blue Nile Basin
Authors: Gebrehiwot S. G. , Ilstedt U. , Gärdenas A. I. , Bishop K.
Published: July 2010

Abstract. We made a hydrological characterization of 32 watersheds (31–4350 km2) in the Blue Nile Basin, using data from a study of water and land resources in the Blue Nile Basin, Ethiopia published in 1964 by the US Bureau of Reclamation (USBR). The USBR document contains data on flow, climate, topography, geology, soil type, and land use for the period from 1959 to 1963. The aim of the study was to identify which combination of watershed variables best explain the variation in the hydrological regime, with special focus to low flow and, what kind of land use low flow might benefit from. Principal Component Analysis (PCA) and Partial Least Square (PLS) were used to analyze the relationship between hydrologic variables (total flow, maximum flow, minimum flow, runoff coefficient, and low flow index) and 30 potential watershed variables. We found that three groups of watershed variables – climate and topography, geology and soil, and land use had almost equal influence on the variation in the hydrologic variables (R2 values ranging from 0.3 to 0.5). The individual variables which were selected based on statistical significance from all groups of explanatory variables were better in explaining the variation. Low flow was positively correlated most strongly to wetland, wood land, rainfall, luvisols, and alluvial soils. Low flow was negatively correlated to grazing land, bush land, tuffs/basalts, eutric-vertisols and riverine forest. We concluded that low flow benefits from the land use types that preserve soil quality and water storage, such as wetland, savannah and woodland, while it was lower in land use resulting in soil degradation. Therefore it provides support to the theory that some land use such as grassland, can promote higher low flow
Mesopause temperature perturbations caused by infrasonic waves as a potential indicator for the detection of tsunamis and other geo-hazards
Authors: Bittner M. , Höppner K. , Pilger C. , Schmidt C.
Published: July 2010

Abstract. Many geo-hazards such as earthquakes, tsunamis, volcanic eruptions, severe weather, etc., produce acoustic waves with sub-audible frequency, so called infrasound. This sound propagates from the surface to the middle and upper atmosphere causing pressure and temperature perturbations. Temperature fluctuations connected with the above mentioned events usually are very weak at the surface, but the amplitude increases with height because of the exponential decrease of atmospheric pressure with increasing altitude. At the mesopause region (80–100 km height) signal amplitudes are about two to three orders of magnitude larger than on the ground. The GRIPS (GRound-based Infrared P-branch Spectrometer) measurement system operated by the German Remote Sensing Data Center of the German Aerospace Center (DLR-DFD) derives temperatures of the mesopause region by observing hydroxyl (OH) airglow emissions in the near infrared atmospheric emission spectrum originating from a thin layer at approximately 87 km height. The GRIPS instrument is in principle suited for the detection of infrasonic signals generated by e.g. tsunamis and other geo-hazards. This is due to the fact that the infrasound caused by such events should induce observable short-period fluctuations in the OH airglow temperatures. First results obtained during a field campaign performed at the Environmental Research Station "Schneefernerhaus", Zugspitze (47.4° N, 11.0° E) from October to December 2008 are presented regarding potential sources of meteorological and orographical origin. An adequate distinction of the overlapping infrasonic signatures caused by different infrasound sources in the OH temperature record is needed for the ascription to the proper source. The approach presented here could form a contribution to a hazard monitoring and early warning system.
Superior Strength and Electrical Conductivity Synergy of Cold‐Drawn Al–Mg–Si–Ce–Cu Wires Produced by Continuous Casting and Rolling
Authors: Niu Guodong , Wang Yu , Mao Jian
Published: May 2024

Al–Mg–Si aluminum wires for overhead power transmission have extensive applications in industry and daily life. Herein, superior strength and electrical conductivity combinations in the aged cold‐drawn Al–Mg–Si–Ce–Cu wires fabricated by continuous casting and rolling are achieved. The cold‐drawn wires exhibit high strength and electrical conductivity combinations of 383 ± 2 MPa, 51.16 ± 0.23% International Annealed Copper Standard (IACS); 373 ± 3 MPa, 51.98 ± 0.25%; and 357 ± 3 MPa, 53.16 ± 0.11% IACS, respectively, when aged at 160, 170, or 180 °C for 24 h. Subgrain boundaries are introduced into alloys by continuous casting and rolling and cold drawing, causing significant lattice distortion within the grains and providing sites for the nucleation of precipitates. Moreover, high‐angle‐annular dark‐field scanning transmission electron microscopy and density functional theory results show that Ce atoms could enter the lattice of β” and replace the Si3 sites, which is energetically preferred. The underlying mechanisms for achieving superior strength–electrical conductivity combination are to introduce subgrain boundaries via continuous casting and rolling and cold drawing for promoting the transformation of solid solution atoms to finely dispersed precipitates, which significantly reduces the scattering of electrons and hence improves the electrical conductivity. This work provides a new strategy for designing high‐strength and high‐conductivity aluminum alloy wire conductors.
Indigo as a Low‐Cost Redox‐Active Sorbent for Electrochemically Mediated Carbon Capture
Authors: Jayarapu Krish N. , Mathur Anmol , Li Xing , Liu Andong , Zhang Lingyu , Kim Jaeeun , Kim Hyunah , Kuk Su Keun , Liu Yayuan
Published: May 2024

Climate change has driven the need for carbon capture to mitigate anthropogenic greenhouse gas emissions, yet current thermochemical methods are hampered by high energy intensities. Electrochemically mediated carbon capture (EMCC) utilizing redox‐active carbon dioxide (CO2) carriers is an attractive alternative for carbon capture. Here, an economical vat dye compound, indigo, is presented, which can reversibly capture and release CO2 upon electrochemical reduction and oxidation, respectively. Electrode and electrolyte engineering strategies are utilized to improve the reversibility and stability of indigo for EMCC. A bench‐scale prototypical fixed‐bed carbon capture device is constructed to demonstrate indigo's EMCC performance under various practically relevant conditions, such as simulated flue gas and extremely dilute sources pertinent to direct air capture. A hybrid sorbent electrode‐gas diffusion layer approach is revealed to alleviate CO2 mass transport limitations, achieving ≈80% CO2 capacity utilization under a 15% CO2 feed stream. Furthermore, a reactive‐diffusive mass transport model is developed to illustrate engineering approaches that can be universally applied to optimize fixed‐bed EMCC systems. This work advances the potential for a class of low‐cost sorbents for EMCC while underscoring the importance of molecular, electrolyte, materials, and device engineering strategies to enable high‐performance carbon capture.
Smart DNA Network Capturing and Destructing Tumor‐Derived Small Extracellular Vesicles at Tumor Sites for Localized Cancer Therapy
Authors: Yang Sen , Tang Jianpu , Cheng Yu , Liu Mingxing , Lv Zhaoyue , Zhang Rui , Zhang Chunzhi , Yao Chi , Yang Dayong
Published: May 2024

Tumor‐derived small extracellular vesicles (sEVs) are proven to play important roles in accelerating the progression of tumors. Destructing the sEVs at tumor sites is therefore a promising route to inhibit tumor progression. Herein, a smart DNA network‐based sEV trap (DNET) is reported, which achieved the specific capture of tumor‐derived sEVs through recognizing sEVs by polyaptamers, and the efficient destruction of sEVs via a photodynamic process at tumor sites. The DNET is constructed through the assembly of two DNA chains generated via rolling circle amplification. The DNA chains contain polyaptamers for capturing sEVs, polyvalent G‐quadruplexes for loading photodynamic reagents, and complementary segments for forming a cross‐linked network. Upon the irradiation of the laser, the captured sEVs in DNET are destructed, causing significant inhibition effects on the migration, invasion, and proliferation of glioblastoma cells. In particular, DNET achieved tumor inhibition rates of 39.70% in the zebrafish tumor model, and 73.10% in the nude mouse tumor model, respectively, demonstrating the significant efficacy of DNET in inhibiting tumor progression.
Constructing an Asymmetric Covalent Triazine Framework to Boost the Efficiency and Selectivity of Visible‐Light‐Driven CO2 Photoreduction
Authors: Qi Guang‐Dong , Ba Dan , Zhang Yu‐Jie , Jiang Xue‐Qing , Chen Zihao , Yang Miao‐Miao , Cao Jia‐Min , Dong Wen‐Wen , Zhao Jun , Li Dong‐Sheng , Zhang Qichun
Published: May 2024

The photocatalytic reduction of CO2 represents an environmentally friendly and sustainable approach for generating valuable chemicals. In this study, a thiophene‐modified highly conjugated asymmetric covalent triazine framework (As‐CTF‐S) is developed for this purpose. Significantly, single‐component intramolecular energy transfer can enhance the photogenerated charge separation, leading to the efficient conversion of CO2 to CO during photocatalysis. As a result, without the need for additional photosensitizers or organic sacrificial agents, As‐CTF‐S demonstrates the highest photocatalytic ability of 353.2 µmol g−1 and achieves a selectivity of ≈99.95% within a 4 h period under visible light irradiation. This study provides molecular insights into the rational control of charge transfer pathways for high‐efficiency CO2 photoreduction using single‐component organic semiconductor catalysts.
Enabling Uniform and Accurate Control of Cycling Pressure for All‐Solid‐State Batteries
Authors: Chen Yu‐Ting , Jang Jihyun , Oh Jin An Sam , Ham So‐Yeon , Yang Hedi , Lee Dong‐Ju , Vicencio Marta , Lee Jeong Beom , Tan Darren H. S. , Chouchane Mehdi , Cronk Ashley , Song Min‐Sang , Yin Yijie , Qian Jianting , Chen Zheng , Meng Ying Shirley
Published: May 2024

All‐solid‐state batteries are emerging as potential successors in energy storage technologies due to their increased safety, stemming from replacing organic liquid electrolytes in conventional Li‐ion batteries with less flammable solid‐state electrolytes. However, all‐solid‐state batteries require precise control over cycling pressure to maintain effective interfacial contacts between materials. Traditional uniaxial cell holders, often used in battery research, face challenges in accommodating electrode volume changes, providing uniform pressure distribution, and maintaining consistent pressure over time. This study introduces isostatic pouch cell holders utilizing air as pressurizing media to achieve uniform and accurately regulated cycling pressure. LiNi0.8Co0.1Mn0.1O2 | Li6PS5Cl | Si pouch cells are fabricated and tested under 1 to 5 MPa pressures, revealing improved electrochemical performance with higher cycling pressures, with 2 MPa as the minimum for optimal operation. A bilayer pouch cell with a theoretical capacity of 100 mAh, cycled with an isostatic pouch cell holder, demonstrated a first‐cycle Coulombic efficiency of 76.9% and a discharge capacity of 173.6 mAh g−1 (88.1 mAh), maintaining 83.6% capacity after 100 cycles. These findings underscore the effectiveness of isostatic pouch cell holders in enhancing the performance and practical application of all‐solid‐state batteries.