bluuebunny/crossref_metadata_2025 huggingface dataset:
Thymelaeaceae
Authors: Manning J. C. , Boatwright J. S.
Published: March 2014

Lasiosiphon rigidus, a new species from the Tankwa Karoo and two new combinations in the genus for South Africa.
Exsiccatae in the bryophyte collection of the National Herbarium, Pretoria
Authors: Van Rooy J.
Published: March 2014

Exsiccatae in the bryophyte collection of the National Herbarium in Pretoria (PRE) are catalogued for the first time. Most of the 66 series represented in PRE were issued in Europe, but the USA is the country where the largest number of exsiccatae originated. The exsiccatae span three centuries, with the earliest specimens issued in 1845 and the latest in 2009. This indicates the long-standing exchange of material and transfer of knowledge between herbaria in South Africa and countries of the northern Hemisphere. Many of the exsiccatae in PRE are incomplete and specimens were received as duplicates in exchange sets rather than exsiccatae. PRE houses a number of important African and southern hemisphere exsiccatae including two different sets of A. Rehmann’s Musci Austro-Africani (1875–1877) and Musci Austro-Africani cont., and R. Ochyra’s Bryophyta Antarctica exsiccata.
Geraniaceae
Authors: Roux J. P.
Published: March 2014

Validating Pelargonium sect. Reniformia.
The Cape genus Micranthus (Iridaceae: Crocoideae), nomenclature and taxonomy
Authors: Goldblatt P. , Manning J. C. , Gereau R. E.
Published: March 2014

The genus Micranthus (Pers.) Eckl., has traditionally been treated as comprising three species, all with virtually identical, bilaterally symmetric, deep or pale blue to white flowers arranged in crowded, 2-ranked spikes and with divided style branches, but differing in their foliage. Examination of plants in the field and herbarium shows that there are four additional species. M. filifolius Goldblatt J.C.Manning, from the Caledon District of the southwestern Western Cape, has up to six, filiform leaves, the blades of at least the lowermost terete and cross-shaped in section, and usually pale blue-mauve flowers. M. simplex Goldblatt J.C.Manning from high elevations on Zebrakop, Piketberg, has the smallest flowers in the genus, white but tinged lilac as they age, linear leaves up to 1.5 mm wide, and undivided style branches. M. cruciatus Goldblatt J.C.Manning, from the northern Cedarberg and Bokkeveld Mtns, has up to four leaves, the lower with linear or terete blades with heavily thickened margins and central vein and relatively large flowers, unusual in having the style dividing at the mouth of the perianth tube into particularly long branches, these deeply divided as is typical of the genus. M. thereianthoides Goldblatt J.C.Manning, from the Paardeberg south of Malmesbury, is unique in the genus in having flowers with an elongate perianth tube. We also document the occurrence of large populations of putative hybrids at some sites. We provide a complete revision of Micranthus with original observations on leaf anatomy, pollen morphology and reproductive biology and discuss its confused taxonomic and nomenclatural history and that of the three common species of the genus, known for over 150 years. In so doing, we neotypify Gladiolus alopecuroides L. (1756) [= Micranthus alopecuroides (L.) Eckl. (1827)], type of the genus, and choose lectotypes for M. plantagineus Eckl. var. junceus Baker (1892) and Gladiolus fistulosus Jacq. Now with seven species, Micranthus remains endemic to the Cape flora region, extending from its extreme northern limit in the Bokkeveld Mtns south-eastwards to Port Elizabeth. We also deal with the genera Paulomagnusia Kuntze and Beilia Kuntze with which Micranthus has sometimes been associated, although both are nomenclatural synonyms of Thereianthus G.J.Lewis, a genus close allied to Micranthus.
High temperature promotes early senescence in primary leaves of sunflower (Helianthus annuus L.) plants
Authors: De la Haba P. , De la Mata L. , Molina E. , Agüera E.
Published: March 2014

De la Haba, P., De la Mata, L., Molina, E. and Agüera, E. 2014. High temperature promotes early senescence in primary leaves of sunflower (Helianthus annuus L.) plants. Can. J. Plant Sci. 94: 659–669. High temperature affects numerous biochemical and physiological traits in plants. Primary leaves of sunflower (Helianthus annuus L.) were collected from plants grown under a control temperature (day/night regime of 23/19°C) or a high temperature (day/night regime of 33/29°C) for 16, 22, 28, 32 or 42 d. Leaves of sunflower plants exposed to high temperature exhibited decreased growth, as reflected by lower specific leaf mass and reduced leaf area as compared with controls. A superior decrease in soluble protein content during leaf life span in plants grown at high temperature relative to control plants (70% vs. 45%, respectively) suggests that high temperature promotes soluble protein degradation in leaves. High temperature also reduces net photosynthetic rate (P N) possibly by decreasing the content in photosynthetic pigments and the stomatal conductance (g s). The activity of nitrate reductase and glutamine synthetase decreased while deaminating activity in glutamate dehydrogenase increased in leaves exposed to high temperature. Our results suggest that high temperature induced early senescence in sunflower leaves, probably as a result of an accumulation of soluble sugars and the associated decrease in starch levels. Oxidative damage resulting from increased H2O2 accumulation and a decline in antioxidant activity may have also contributed to accelerated senescence of primary leaves at high temperature.
TNO-MACC_II emission inventory: a multi-year (2003–2009) consistent high-resolution European emission inventory for air quality modelling
Authors: Kuenen J. J. P. , Visschedijk A. J. H. , Jozwicka M. , Denier van der Gon H. A. C.
Published: March 2014

Abstract. Emissions to air are reported by countries to EMEP. The emissions data are used for country compliance checking with EU emission ceilings and associated emission reductions. The emissions data are also necessary as input for air quality modelling. The quality of these "official" emissions varies across Europe. As alternative to these official emissions, a spatially explicit high resolution emission inventory (7 km × 7 km) for UNECE-Europe for all years between 2003 and 2009 for the main air pollutants was made. The primary goal was to supply air quality modellers with the input they need. The inventory was constructed by using the reported emission national totals by sector where the quality is sufficient. The reported data were analysed by sector in detail, and completed with alternative emission estimates as needed. This resulted in a complete emission inventory for all countries. For particulate matter, for each source emissions have been split in coarse and fine particulate matter, and further disaggregated to EC, OC, SO4, Na and others using fractions based on literature. Doing this at the most detailed sectoral level in the database implies that a consistent set was obtained across Europe. This allows better comparisons with observational data which can, through feedback, help to further identify uncertain sources and/or support emission inventory improvements for this highly uncertain pollutant. The resulting emission dataset was spatially distributed consistently across all countries by using proxy parameters. Point sources were spatially distributed using the specific location of the point source. The spatial distribution for the point sources was made year-specific. The TNO-MACC_II is an update of the TNO-MACC emission dataset. Major updates included the time extension towards 2009, use of the latest available reported data (including updates and corrections made until early 2012) and updates in distribution maps.
Technical Note: 30 years of HIRS data of upper tropospheric humidity
Authors: Gierens K. , Eleftheratos K. , Shi L.
Published: March 2014

Abstract. We use 30 years of intercalibrated HIRS data to produce a 30 year data set of upper tropospheric humidity with respect to ice (UTHi). Since the required brightness temperatures (channels 12 and 6, T12 and T6) are intercalibrated to different versions of the HIRS sensors (HIRS/2 and HIRS/4) it is necessary to convert the channel 6 brightness temperatures which are intercalibrated to HIRS/4 into equivalent brightness temperatures intercalibrated to HIRS/2, which is achieved using a linear regression. Using the new regression coefficients we produce daily files of UTHi, T12 and T6, for each NOAA satellite and METOP-A, which carry the HIRS instrument. From this we calculate daily and monthly means in 2.5° × 2.5° resolution for the northern mid-latitude zone 30 to 60° N. As a first application we calculate decadal means of UTHi and the brightness temperatures for the two decades 1980–1989 and 2000–2009. We find that the humidity mainly increased from the 1980s to the 2000s and that this increase is highly statistically significant in large regions of the considered mid-latitude belt. The main reason for this result and its statistical significance is the corresponding increase of the T12 variance. Changes of the mean brightness temperatures are less significant.
Identifying vital effects in Halimeda algae with Ca isotopes
Authors: Blättler C. L. , Stanley S. M. , Henderson G. M. , Jenkyns H. C.
Published: March 2014

Abstract. Geochemical records of biogenic carbonates provide some of the most valuable records of the geological past, but are often difficult to interpret without a mechanistic understanding of growth processes. In this experimental study, Halimeda algae are used as a test organism to untangle some of the specific factors that influence their skeletal composition, in particular their Ca-isotope composition. Algae were stimulated to precipitate both calcite and aragonite by growth in artificial Cretaceous seawater. The Ca-isotope fractionation of the algal calcite is much smaller than that for the algal aragonite, similar to the behaviour observed in inorganic precipitates. However, the carbonate from Halimeda is isotopically heavier than inorganic forms, likely due to Rayleigh distillation within the algal intercellular space. In identifying specific vital effects and the magnitude of their influence on Ca-isotope ratios, this study suggests that mineralogy has a first-order control on the Ca-isotope budget of the carbonate sink and the Ca-isotope composition of seawater.
Mapping with MAV: Experimental Study on the Contribution of Absolute and Relative Aerial Position Control
Authors: Skaloud J. , Rehak M. , Lichti D.
Published: March 2014

Abstract. This study highlights the benefit of precise aerial position control in the context of mapping using frame-based imagery taken by small UAVs. We execute several flights with a custom Micro Aerial Vehicle (MAV) octocopter over a small calibration field equipped with 90 signalized targets and 25 ground control points. The octocopter carries a consumer grade RGB camera, modified to insure precise GPS time stamping of each exposure, as well as a multi-frequency/constellation GNSS receiver. The GNSS antenna and camera are rigidly mounted together on a one-axis gimbal that allows control of the obliquity of the captured imagery. The presented experiments focus on including absolute and relative aerial control. We confirm practically that both approaches are very effective: the absolute control allows omission of ground control points while the relative requires only a minimum number of control points. Indeed, the latter method represents an attractive alternative in the context of MAVs for two reasons. First, the procedure is somewhat simplified (e.g. the lever-arm between the camera perspective and antenna phase centers does not need to be determined) and, second, its principle allows employing a single-frequency antenna and carrier-phase GNSS receiver. This reduces the cost of the system as well as the payload, which in turn increases the flying time.
SINGULAR VALUE DECOMPOSITION-BASED ROBUST CUBATURE KALMAN FILTER FOR AN INTEGRATED GPS/SINS NAVIGATION SYSTEM
Authors: Zhang Q. , Meng X. , Zhang S. , Wang Y.
Published: March 2014

Abstract. A new nonlinear robust filter is proposed in this paper to deal with the outliers of an integrated GPS/SINS navigation system. The influence of different design parameters for H∞ cubature Kalman filter is analysed. It is found that when the design parameter is smaller, the robustness of the filter is stronger. However, the design parameter is easily out of step with the Riccati equation and the filter is easy to diverge. In this respect, the singular value decomposition algorithm is employed to replace Cholesky decomposition in the robust cubature Kalman filter. On the wider conditions for design parameter, the new filter is more robust. The testing results demonstrate that the proposed filter algorithm is more reliable and effective in dealing the data sets produced by the integrated GPS/SINS system.
VERIFICATION AND IMPROVING PLANIMETRIC ACCURACY OF AIRBORNE LASER SCANNING DATA WITH USING PHOTOGRAMMETRIC DATA
Authors: Bakuła K. , Dominik W. , Ostrowski W.
Published: March 2014

Abstract. In this study results of planimetric accuracy of LIDAR data were verified with application of intensity of laser beam reflection and point cloud modelling results. Presented research was the basis for improving the accuracy of the products from the processing of LIDAR data, what is particularly important in issues related to surveying measurements. In the experiment, the true-ortho from the large-format aerial images with known exterior orientation were used to check the planimetric accuracy of LIDAR data in two proposed approaches. First analysis was carried out by comparison the position of the selected points identifiable on true-ortho from aerial images with corresponding points in the raster of reflection intensity reflection. Second method to verify planimetric accuracy used roof ridges from 3D building models automatically created from LIDAR data being intersections of surfaces from point cloud. Both analyses were carried out for 3 fragments of LIDAR strips. Detected systematic planimetric error in size of few centimetres enabled an implementation of appropriate correction for analyzed data locally. The presented problem and proposed solutions provide an opportunity to improve the accuracy of the LiDAR data. Such methods allowed for efficient use by specialists in other fields not directly related to the issues of orientation and accuracy of photogrammetric data during their acquisition and pre-processing
DETECTION OF CRITICAL CAMERA CONFIGURATIONS FOR STRUCTURE FROM MOTION
Authors: Michelini M. , Mayer H.
Published: March 2014

Abstract. This paper deals with the detection of critical, i.e., poor or degenerate camera configurations, with a poor or undefined intersection geometry between views. This is the basis for a calibrated Structure from Motion (SfM) approach employing image triplets for complex, unordered image sets, e.g., obtained by combining terrestrial images and images from small Unmanned Aerial Systems (UAS). Poor intersection geometry results from a small ratio between the baseline length and the depth of the scene. If there is no baseline between views, the intersection geometry becomes undefined. Our approach can detect image pairs without or with a very weak baseline (motion degeneracy). For the detection we have developed various metrics and evaluated them by means of extensive experiments with about 1500 image pairs. The metrics are based on properties of the reconstructed 3D points, such as the roundness of the error ellipsoid. The detection of weak baselines is formulated as a classification problem using the metrics as features. Machine learning techniques are applied to improve the classification. By taking into account the critical camera configurations during the iterative composition of the image set, a complete, metric 3D reconstruction of the whole scene could be achieved also in this case. We sketch our approach for the orientation of unordered image sets and finally demonstrate that the approach is able to produce very accurate and reliable orientations.
THE PERIGEO PROJECT: INERTIAL AND IMAGING SENSORS PROCESSING, INTEGRATION AND VALIDATION ON UAV PLATFORMS FOR SPACE NAVIGATION
Authors: Molina P. , Angelats E. , Colomina I. , Latorre A. , Montaño J. , Wis M.
Published: March 2014

Abstract. The PERIGEO R&D project aims at developing, testing and validating algorithms and/or methods for space missions in various field of research. This paper focuses in one of the scenarios considered in PERIGEO: navigation for atmospheric flights. Space missions heavily rely on navigation to reach success, and autonomy of on-board navigation systems and sensors is desired to reach new frontiers of space exploration. From the technology side, optical frame cameras, LiDAR and inertial technologies are selected to cover the requirements of such missions. From the processing side, image processing techniques are developed for vision-based relative and absolute navigation, based on point extraction and matching from camera images, and crater detection and matching in camera and LiDAR images. The current paper addresses the challenges of space navigation, presents the current developments and preliminary results, and describes payload elements to be integrated in an Unmanned Aerial Vehicle (UAV) for in-flight testing of systems and algorithms. Again, UAVs are key enablers of scientific capabilities, in this case, to bridge the gap between laboratory simulation and expensive, real space missions.
OFF-THE-SHELF VIDEOGRAMMETRY – A SUCCESS STORY
Authors: Rupnik E. , Jansa J.
Published: March 2014

Abstract. Since the time Brown introduced the concept of self-calibration, it was known that there was no impediment in using consumer grade devices for metric purposes. Today, dSLR cameras are knowingly the standard photogrammetric tool in applications when time is not an issue, thus images can be taken sequentially. Nonetheless, albeit available with standard video signal, there has been little interest in applying them to observe dynamic scenes. In this paper we present a methodology to use dSLR cameras for shape and motion reconstruction at frequency of 30Hz. Particular focus is put on calibration and orientation issues, in static and dynamic cases i.e. cameras also undergoing a change in position during the measurement. Performance of the system was validated with results obtained by a system of superior quality.
Dynamics of turbulent western boundary currents at low latitude in a shallow water model
Authors: Akuetevi C. Q. C. , Wirth A.
Published: March 2014

Abstract. The dynamics of low latitude turbulent western boundary currents, subject to two different types of idealized wind forcing, Monsoon Wind and Trade Wind, is considered using numerical results from integrations of a reduced gravity shallow-water model. For viscosity values of 1000 m2 s−1 and above, the boundary layer dynamics compares well to the analytical solutions of the Munk-layer and the inertial-layer, derived from quasigeostrophic theory. Modifications due to variations in the layer thickness (vortex stretching) are only important close to the boundary. When the viscosity is reduced the boundary layer becomes turbulent and coherent structures in form of anticyclonic eddies, bursts (violent detachments of the viscous sub-layer) and dipoles appear. Three distinct boundary layers emerge, the viscous sub-layer, the advective boundary layer and the extended boundary layer. The first is characterized by a dominant vorticity balance between the viscous transport and the advective transport of vorticity. The second by a balance between the advection of planetary vorticity and the advective transport of relative vorticity. The extended boundary layer is the area to which turbulent motion from the boundary extends. The scaling of the three boundary layer thicknesses with viscosity is evaluated. A pragmatic approach to determine the eddy viscosity diagnostically for coarse resolution numerical models is proposed.
Bioguided Identification of Antifungal and Antiproliferative Compounds from the Brazilian Orchid Miltonia flavescens Lindl.
Authors: Porte Leticia F. , Santin Silvana M. O. , Chiavelli Lucas U. R. , Silva Cleuza C. , Faria Terezinha J. , Faria Ricardo T. , Carvalho João E. , Pomini Armando M.
Published: March 2014

The Orchidaceae family is appreciated worldwide for the beauty of its flowers, and hundreds of species of this family occur in Brazil. Yet little is known about the potential of orchids for therapeutic application. We have investigated bioactive compounds produced by the South Brazilian orchid Miltonia flavescens Lindl. Bioguided studies with the fungus Cladosporium herbarum allowed the identification of hydrocinnamic acid as the active antifungal compound. In addition, the chloroform fraction exhibited an interesting activity against human cancer cells, and 5,7-dihydroxy-6,4'- dimethoxyflavone isolated from this fraction was found to be active against seven human cancer cell lines, including NCI/ADR-RES ovary sarcoma, with an IC50 value of 2.6 mg/mL. This is the first report on the cytostatic activity of this flavone against human ovary sarcoma.
Delirium, a Symptom of UTI in the Elderly: Fact or Fable? A Systematic Review*
Authors: Balogun Seki A. , Philbrick John T.
Published: March 2014

BackgroundIn geriatrics, delirium is widely viewed as a consequence of and, therefore, a reason to initiate workup for urinary tract infection (UTI). There is a possibility that this association is overestimated. To determine the evidence behind this clinical practice, we undertook a systematic review of the literature linking delirium with UTI.MethodsA MEDLINE search was conducted from 1966 through 2012 using the MESH terms “urinary tract infection” and “delirium”, limited to humans, age 65 and older. The search identified 111 studies. Of these, five met our inclusion criteria of being primary studies that addressed the association of UTI and delirium. The studies were four cross-sectional observational studies and one case series. No randomized control trials were identified. All studies were published between 1988 and 2011. Four collected data retrospectively and one prospectively, with study sizes ranging from 14 to 1,285. The methodological strength of the studies was evaluated using six standards adapted from a previous systematic review.ResultsOnly two of the five studies adequately matched or statistically adjusted for differences in comparison groups. None of the studies evaluated subjects with equal intensity for the presence of delirium and UTI, nor did they have objective criteria for either diagnosis. In subjects with delirium, UTI rates ranged from 25.9% to 32% compared to 13% in those without delirium. In subjects with UTI, delirium rates ranged from 30% to 35%, compared to 7.7% to 8% in those without UTI.ConclusionsFew studies have examined the association between UTI and delirium. Though the studies examined conclude that there is an association between UTI and delirium, all of them had significant methodological flaws that likely led to biased results. Therefore, it is difficult to ascertain the degree to which urinary tract infections cause delirium. More research is needed to better define the role of UTI in delirium etiology.
Effect of Biofertilizer Addition on Nitrous Oxide Emission
Authors: Endah Retnaningrum  , Irfan D. Prijambada  , Sukarti Moeljopawiro  , Budi S. Daryono
Published: March 2014

Application of nitrogen fixing biofertilizer, such as Azotobacter, has a potential for reducing nitrous oxide(N2O) emission. The aim of this study was to examine the effect of nitrogen fixing biofertilizer addition to common practices of urea and fresh cattle manure usages for maize (Zea mays L.) growing on N2O emission. The field experiment was conducted at GunungKidul, Yogyakarta, Indonesia. The treatments were addition of fresh cattle manure (M), fresh cattle manure added with nitrogen fixing biofertilizer (MB), urea (U), urea added with nitrogen fixing biofertilizer (UB), and control (no N fertilizer added). Nitrogen contents of the added urea and fresh cattle manure were adjusted to be equal. Urea and fresh cattle manure were given three times throughout the experiment period, i.e. 12, 30, and 48 days after planting (DAP). Urea was given at a rate of 44, 29, and 15 kg.ha-1, respectively while fresh cattle manure was given at a rate of 6000, 4000, and 2000 kg.ha-1, respectively. The emitted N2O was collected using a closed-chamber method at 24, 42, 60, and 72 DAP and were determined using Gas Chromatograph. Soil properties including available N (NH4+-N and NO3–-N) and organic C contents were also analyzed. On the harvesting time, the harvest index and the grain yield were determined. Biofertilizer addition influence decomposition process of cattle manure and urea that led to mineralization and nitrification of residual organic matterand hence to cause soil NH4+N in the order concentration of M treatment > MB > U > UB>C, and soil NO3–-N of MB treatment > M > U > UB>C. Reduction of NO3–N was resulted in the highest N2O emission of M >U>MB>UB>C(P < 0.01). The grain yield, and harvest index of maize wereresulted in the order value of MB> UB > U > M>C treatments.Available mineral N and soil organic C contents strongly affected N2O emission (P < 0.01).The results suggested that biofertilizer addition to common agricultural practices reduce N2O emission and simultaneusly increased grain yield, and harvest index of maize.
On Modelling Migrant Behavior Driven by Imitation
Authors: Accinelli Elvio , Carrera Edgar J. Sánchez , Salas Osvaldo
Published: March 2014

This paper studies the evolutionary dynamics of migration. We argue that, under bounded rationality, the strategic foundations of the migrant behavior are based in the imitation of peers. We show that any migratory flow can be modeled from a dynamical system, whose parameters reflect the social and economic policies implemented by the decision maker and the rules of the imitative process followed by the population. Education or technological innovation subsidies can lead to an increasing flow of skilled workers to the country in which this policy is more intensively developed. Impact of such subsidies on migration processes can be easily analyzed based on our model. We show that an economy may avoid skilled workers losses as a result of migration flows, only if the number of local firms investing in research and development exceeds a certain threshold value. Moreover, if this value is exceeded, such an economy is attending a positive process of imitation of skilled workers.
A simulation-based dynamic traffic assignment model with combined modes
Authors: Meng Meng , Shao Chunfu , Zeng Jingjing , Dong Chunjiao
Published: March 2014

This paper presents a dynamic traffic assignment (DTA) model for urban multi-modal transportation network by con­structing a mesoscopic simulation model. Several traffic means such as private car, subway, bus and bicycle are con­sidered in the network. The mesoscopic simulator consists of a mesoscopic supply simulator based on MesoTS model and a time-dependent demand simulator. The mode choice is si­multaneously considered with the route choice based on the improved C-Logit model. The traffic assignment procedure is implemented by a time-dependent shortest path (TDSP) al­gorithm in which travellers choose their modes and routes based on a range of choice criteria. The model is particularly suited for appraising a variety of transportation management measures, especially for the application of Intelligent Trans­port Systems (ITS). Five example cases including OD demand level, bus frequency, parking fee, information supply and car ownership rate are designed to test the proposed simulation model through a medium-scale case study in Beijing Chaoy­ang District in China. Computational results illustrate excel­lent performance and the application of the model to analy­sis of urban multi-modal transportation networks.
Three‐dimensional GPS ionospheric tomography over Japan using constrained least squares
Authors: Seemala Gopi K. , Yamamoto Mamoru , Saito Akinori , Chen Chia‐Hung
Published: March 2014

A new three‐dimensional GPS ionospheric tomography technique is developed that uses total electron content (TEC) data from the dense Global Position System (GPS) receiver network, GPS Earth Observation Network (GEONET) in Japan, and it will not require an ionospheric model as the initial guess that will bias the reconstruction of electron density. The GEONET is operated by Geospatial Information Authority of Japan and consists of more than 1200 receivers; this high density and wide coverage helps to reconstruct the electron density distribution in the ionosphere with high spatial resolution. This tomography technique uses a constrained least squares fit to reconstruct the three‐dimensional electron density distributions. This method is different to most other techniques as they require a background ionospheric model as an initial guess that could bias the reconstructed electron density. It rather uses a prior condition that the electron density should not exceed a certain value that is determined by the restrain parameter, which is derived from the NeQuick model. Its independency of the initial guess from a model will make it useful even in disturbed conditions. This paper presents results that are obtained by using this new tomographic technique. The reconstruction of three‐dimensional ionospheric tomograms is demonstrated using the GPS data, and the reliability and robustness are checked with simulated tomograms obtained using the synthetic GPS‐TEC data produced using NeQuick model.
25th Anniversary Article: High‐Mobility Hole and Electron Transport Conjugated Polymers: How Structure Defines Function
Authors: Olivier Yoann , Niedzialek Dorota , Lemaur Vincent , Pisula Wojciech , Müllen Klaus , Koldemir Unsal , Reynolds John R. , Lazzaroni Roberto , Cornil Jérôme , Beljonne David
Published: March 2014

The structural organization of three different families of semicrystalline π‐conjugated polymers is reported (poly(3‐hexylthiophene) (P3HT), poly[2,6‐(4,4‐bis‐alkyl‐4H‐cyclopenta‐[2,1‐b;3,4‐b0]‐dithiophene)‐alt‐4,7‐(2,1,3‐benzothiadiazole)](cyclopentadithiophene‐benzothiadiazole) (CDT‐BTZ) and poly(N,N"‐bis‐2‐octyldodecylnaphtalene‐1,4,5,8‐bis‐dicarboximide‐2,6‐diyl‐alt‐5,5–2,2‐bithiophene (P(NDI2OD‐T2))). These have triggered significant interest for their remarkable charge‐transport properties. By performing molecular mechanics/dynamics simulations with carefully re‐parameterized force fields, it is illustrated in particular how the supramolecular organization of these conjugated polymers is driven by an interplay between the length and nature of the conjugated monomer unit and the packing of their alkyl side chains, and to what extent it impacts the charge‐carrier mobility, as monitored by quantum‐chemical calculations of the intermolecular hopping transfer integrals. This Progress Report is concluded by providing generic guidelines for the design of materials with enhanced degrees of supramolecular organization.
Transferring Lithium Ions in Nanochannels: A PEO/Li+ Solid Polymer Electrolyte Design
Authors: Yang Ling‐Yun , Wei Da‐Xiu , Xu Min , Yao Ye‐Feng , Chen Qun
Published: March 2014

A new category of crystalline polymer electrolyte prepared by the supramolecular self‐assembly of polyethylene oxide (PEO), α‐cyclodextrin (α‐CD), and LiAsF6 is reported. The polymer electrolyte consists of the nanochannels formed by α‐CDs in which the PEO/Li+ complexes are confined. The nanochannels formed by α‐CD provide the pathway for the directional motion of Li+ ions and at the same time prevent the access of the anions by size exclusion, resulting in good separation of the Li+ ions and the anions. The conductivity of the reported material is 30 times higher than that of the comparable PEO/Li+ complex crystal at room temperature. By using state‐of‐art solid‐state NMR spectroscopy, the structure and dynamics of the material were investigated in detail. The dynamics of the Li+ ions was studied and correlated to the ionic conductivity of the material.
Templated Synthesis of Nitrogen‐Enriched Nanoporous Carbon Materials from Porogenic Organic Precursors Prepared by ATRP
Authors: Wu Dingcai , Li Zhenghui , Zhong Mingjiang , Kowalewski Tomasz , Matyjaszewski Krzysztof
Published: March 2014

A facile templated synthesis of functional nanocarbon materials with well‐defined spherical mesopores is developed using all‐organic porogenic precursors comprised of hairy nanoparticles with nitrogen‐rich polyacrylonitrile shells grafted from sacrificial cross‐linked poly(methyl methacrylate) cores (xPMMA‐g‐PAN). Such shape‐persistent all‐organic nanostructured precursors, prepared using atom transfer radical polymerization (ATRP), assure robust formation of template nanostructures with continuous PAN precursor matrix over wide range of compositions, and allow for removal of the sacrificial template through simple thermal decomposition. Carbon materials prepared using this method combine nitrogen enrichment with hierarchical nanostructure comprised of microporous carbon matrix interspersed with mesopores originating from sacrificial xPMMA cores, and thus perform well as CO2 adsorbents and as supercapacitor electrodes.
Filaggrin‐Peptide mit β‐Haarnadel‐Struktur binden Rheuma‐Antikörper
Authors: Fischer Sabrina , Geyer Armin
Published: March 2014

In ELISA‐Tests zur Früherkennung von rheumatoider Arthritis (RA) dienen synthetische Filaggrin‐Peptide als Antigene für rheumaspezifische Autoantikörper (“anti‐citrullinated peptide antibody”, ACPA). Hier wird ein Peptid vorgestellt, welches das Bindungsepitop von ACPA in Form einer stabil faltenden β‐Haarnadel‐Struktur präsentiert. NMR‐Spektroskopie belegt die Homogenität der Faltung des Peptids, und so kann erstmals ein Strukturvorschlag für die antikörpergebundene Konformation des Epitops erstellt werden.
Ubiquinone‐Rhodol (UQ‐Rh) for Fluorescence Imaging of NAD(P)H through Intracellular Activation
Authors: Komatsu Hirokazu , Shindo Yutaka , Oka Kotaro , Hill Jonathan P. , Ariga Katsuhiko
Published: March 2014

The nicotinamide adenine dinucleotide (NAD) derivatives NADH and NADPH are critical components of cellular energy metabolism and operate as electron carriers. A novel fluorescent ubiquinone‐rhodol derivative (UQ‐Rh) was developed as a probe for NAD(P)H. By using the artificial promoter [(η5‐C5Me5)Ir(phen)(H2O)]2+, intracellular activation and imaging of NAD(P)H were successfully demonstrated. In contrast to bioorthogonal chemistry, this “bioparallel chemistry” approach involves interactions with native biological processes and could potentially be used to control or investigate cellular systems.
Divergent Total Syntheses of Lyconadins A and C
Authors: Yang Yang , Haskins Christopher W. , Zhang Wandi , Low Pui Leng , Dai Mingji
Published: March 2014

Divergent and concise total syntheses of two lycopodium alkaloids, lyconadins A and C have been developed. The synthesis of lyconadin A, having potent neurotrophic activity, features an efficient one‐pot ketal removal and formal aza‐[4+2] cyclization to form the cagelike core structure. A tandem ketal removal/Mannich reaction was developed to build the tricyclic structure of lyconadin C. Both lyconadins A and C were synthesized from a pivotal intermediate.
Electronic Metal–Support Interactions in Single‐Atom Catalysts
Authors: Hu Pingping , Huang Zhiwei , Amghouz Zakariae , Makkee Michiel , Xu Fei , Kapteijn Freek , Dikhtiarenko Alla , Chen Yaxin , Gu Xiao , Tang Xingfu
Published: March 2014

The synthesis of single‐atom catalysts and the control of the electronic properties of catalytic sites to arrive at superior catalysts is a major challenge in heterogeneous catalysis. A stable supported single‐atom silver catalyst with a controllable electronic state was obtained by anti‐Ostwald ripening. An electronic perturbation of the catalytic sites that is induced by a subtle change in the structure of the support has a strong influence on the intrinsic reactivity. The higher depletion of the 4d electronic state of the silver atoms causes stronger electronic metal–support interactions, which leads to easier reducibility and higher catalytic activity. These results may improve our understanding of the nature of electronic metal–support interactions and lead to structure–activity correlations.
Supramolecular Complexes of Multivalent Cholesterol‐Containing Polymers to Solubilize Carbon Nanotubes in Apolar Organic Solvents
Authors: Nguendia Jules Zeuna , Zhong Weiheng , Fleury Alexandre , De Grandpré Guillaume , Soldera Armand , Sabat Ribal Georges , Claverie Jerome P.
Published: March 2014

Copolymers of 2‐ethylhexyl acrylate (EHA) and cholesteryloxycarbonyl‐2‐hydroxymethacrylate (CEM) were prepared by reversible addition–fragmentation chain‐transfer (RAFT) polymerization. Supramolecular complexes of these copolymers with carbon nanotubes (CNTs) were soluble in THF, toluene, and isooctane. The colloidal solutions remained stable for months without aggregation. The rationale for the choice of CEM was based on the high adsorption energy of cholesterol on the CNT surface, as computed by DFT calculations. Adsorption isotherms were experimentally measured for copolymers of various architectures (statistical, diblock, and star copolymers), thereby demonstrating that 2–5 cholesterol groups were adsorbed per polymer chain. Once the supramolecular complex had dried, the CNTs could be easily resolubilized in isooctane without the need for high‐power sonication and in the absence of added polymer. Analysis by atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) indicated that the CNTs were devoid of bundles. The supramolecular complexes could also be employed in an inverse emulsion polymerization of 2‐hydroxyethylmethacrylate (HEMA) in isooctane and dodecane, thereby leading to the formation of a continuous polymeric sheath around the CNTs. Thus, this technique leads to the formation of very stable dispersions in non‐polar organic solvents, without altering the fundamental properties of the CNTs.
Base‐Catalyzed NN Bond Cleavage of Hydrazones: Synthesis of α‐Amino Ketones
Authors: Tang Hai‐Tao , Zhou Yun‐Bing , Zhu Yu , Sun Hong‐Chao , Lin Min , Zhan Zhuang‐Ping
Published: March 2014

An efficient Cs2CO3‐promoted synthesis of α‐amino ketones using hydrazines, aldehydes, and α‐haloketones as starting materials through a cascade condensation/nucleophilic substitution/NN bond cleavage route is developed. The carbonyl group plays a key role in this novel NN bond cleavage process.
Preparation of Nitrogen‐Doped Porous Carbon Nanofibers and the Effect of Porosity, Electrical Conductivity, and Nitrogen Content on Their Oxygen Reduction Performance
Authors: Yang Dae‐Soo , Chaudhari Sudeshna , Rajesh Kizhakke Palleeri , Yu Jong‐Sung
Published: March 2014

Nitrogen‐doped carbon nanostructures are considered as a possible alternative to platinum‐based catalysts for fuel cells. The surface density of catalytic sites, electrical conductivity, and nitrogen content play important roles in designing electrode materials for fuel cells. Herein, N‐doped carbon fibers are prepared by electrospinning the poly(acrylonitrile) (PAN) solution followed by carbonization. Some of the key issues of the oxygen reduction reaction (ORR) are addressed in terms of nitrogen content, porosity, and electrical conductivity in the N‐containing carbon nanofibrous system. Nitrogen content and the amount of the graphitic phase are varied by changing the carbonization temperature. In addition, N‐doped carbon fibers with high porosity are prepared by electrospinning the solution mixture of poly(ethylene oxide) (PEO)/PAN followed by carbonization, and the porosity is tuned by varying the ratio of PEO to PAN. The effect of porosity or the surface density of catalytic sites on the ORR is studied. A medium porous sample prepared from the PEO/PAN mixture in a 1:1 ratio by carbonization at 1000 °C is found to be favorable for improved ORR performance for such a system. The observations made herein are explained in terms of trade‐offs between electrical conductivity, nitrogen content, and surface density of active sites.
Numerical Simulation of Oil‐Water Core Annular Flow in a U‐Bend Based on the Eulerian Model
Authors: Jiang Fan , Wang Yijun , Ou Jiajie , Chen Conggui
Published: March 2014

The oil‐water core annular flow through a U‐bend is simulated by computational fluid dynamics based on the Eulerian model. More flow parameters and the effect of annulus thickness on core annular flow are discussed. Conformity between the simulated and experimental data is observed. The development of oil‐water core annular flow in the U‐bend is analyzed, and the distributions of pressure and velocity are discussed. Results of the Eulerian model and volume‐of‐fluid (VOF) model are compared and the influence of oil properties on total pressure gradient is investigated. The suitable range of annulus thickness is identified. The results provide suitable operation conditions for designing the U‐bend pipefitting.
Modelling of Reactive Drying Processes Using the Example of Spray Polymerisation
Authors: Säckel Winfried , Nieken Ulrich
Published: March 2014

Reaktive Sprühtrocknungsprozesse wie Sprühpolymerisationen sind im Hinblick auf die Prozessintensivierung sehr interessant. Bisherige Forschungsarbeiten dazu basieren allerdings fast ausschließlich auf Experimenten. In diesem Beitrag wird ein Einzeltropfenmodell der Sprühpolymerisation vorgestellt, welches das Reaktions‐Diffusions‐System innerhalb eines Tropfens im Spray eindimensional ortsaufgelöst abbildet. Somit lassen sich Auswirkungen der Prozessparameter und Materialeigenschaften auf das Polymerisationsergebnis und wichtige Kenngrößen wie Zahlen‐ und Massenmittel der Kettenlängenverteilung abschätzen.
Investigation of Platinum Dispersed on Reduced Graphene Oxide‐supported Tungsten Carbide via Sacrificial Cu Adlayers for Methanol Oxidation
Authors: Shi Meiqin , Zhao Di , Liu Weiming , Chu Youqun , Ma Chun'an
Published: March 2014

Reduced graphene oxide‐supported tungsten carbide composite (WC/RGO) was prepared by program‐controlled reduction‐carburization technique. Scanning electron microscope (SEM) and transmission electron microscope (TEM) show that WC nanoparticles with a narrow distribution (10–20 nm) are highly dispersed both on the edge and between the layers of RGO. And then it was used as a support to load different low contents (no more than 0.4 wt%) of Pt via sacrificial Cu adlayers. The morphology and the electrocatalytic activity of the prepared catalysts were characterized by TEM and cyclic voltammograms (CV), respectively. The results indicate that a small amount of isolated Pt atoms show low or even no activity for methanol oxidation. With the increasing deposition cycles, the content of Pt and the ensembles of neighboring Pt atoms are increased, which makes the onset potential shift negatively and mass current density increase. The results demonstrate that controllable amount of Pt can be deposited on WC/RGO by galvanic displacement with Cu, and the extent and domain of Pt loading affect the electrochemical performance. Meanwhile, this research also provides another route to prepare a catalyst with ultra low noble metal on WC/RGO for solving the problem of high cost of the catalyst.
Status of Dye Solar Cell Technology as a Guideline for Further Research
Authors: Hinsch Andreas , Veurman Welmoed , Brandt Henning , Flarup Jensen Katrine , Mastroianni Simone
Published: March 2014

Recently, the first commercial dye solar cell (DSC) products based on the mesoscopic principle were successfully launched. Introduction to the market has been accompanied by a strong increase in patent applications in the field during the last four years, which is a good indication of further commercialization activity. Materials and cell concepts have been developed to such extent that easy uptake by industrial manufacturers is possible. The critical phase for broad market acceptance has therefore been reached, which implies focusing on standardization‐related research topics. In parallel the number of scientific publications on DSC is growing further (>3500 since 2012), and the range of new or renewed fundamental topics is broadening. A recent example is the introduction of the perovskite mesoscopic cell, for which an efficiency of 14.1 % has been certified. Thus, a growing divergence between market introduction and research could be the consequence. Herein, an attempt is made to show that such an unwanted divergence can be prevented, for example, by developing suitable reference‐type cell and module concepts as well as manufacturing routes. An in situ cell manufacturing concept that can be applied to mesoscopic‐based solar cells in a broader sense is proposed. As a guideline for future module concepts, recent results for large‐area, glass‐frit‐sealed DSC modules from efficiency studies (6.6 % active‐area efficiency) and outdoor analysis are discussed. Electroluminescence measurements are introduced as a quality tool. Another important point that is addressed is sustainability, which affects both market introduction and the direction of fundamental research.
pH‐Controlled topologies of two Co(II) complexes based on 5‐Nitro‐1,2,3‐benzenetricarboxylic acid and 1,6‐Bis(1,2,4‐triazole‐1‐yl)hexane
Authors: Han Min‐Le , Wang Sheng‐Chun , Feng Dan‐Feng
Published: March 2014

Two new Co(II) coordination polymers, [Co(Hnbta)(bth)]n (1) and {[Co3(nbta)2(bth)3(H2O)]·H2O}n (2), (H3nbta = 5‐nitro‐1,2,3‐benzenetricarboxylic acid and bth = 1,6‐bis(1,2,4‐triazole‐1‐yl)hexane), have been synthesized under different pH values through hydrothermal reactions. Both complexes were characterized by elemental analysis, IR spectra, thermogravimetric analysis (TGA), and single‐crystal X‐ray crystallography. Complex 1 exhibits a 3D polythreaded network based on 4‐connected sql 2D layer. Complex 2 has a (4,4,5)‐connected trinodal 3D pillar‐layered network with a (42·64)2(42·67·8)2(64·82) topology. Magnetic susceptibility measurements indicate that complexes 1 and 2 show weak antiferromagnetic interactions between the adjacent Co(II) ions.
Mineralocorticoid receptor signaling reduces numbers of circulating human naïve T cells and increases their CD62L, CCR7, and CXCR4 expression
Authors: Besedovsky Luciana , Linz Barbara , Born Jan , Lange Tanja
Published: March 2014

The role of mineralocorticoid receptors (MRs) in human T‐cell migration is not yet understood. We have recently shown that the MR antagonist spironolactone selectively increases the numbers of circulating naïve and central memory T cells during early sleep, which is the time period in the 24 h cycle hallmarked by predominant MR activation. To investigate whether this effect is specific to spironolactone's blockade of MRs and to study the underlying molecular mechanisms, healthy humans were given the selective MR‐agonist fludrocortisone or placebo and numbers of eight T‐cell subsets and their CD62L and CXCR4 expression were analyzed. Fludrocortisone selectively reduced counts of naïve CD4+, central memory CD4+, and naïve CD8+ T cells and increased CXCR4 expression on the naïve subsets. In complementing in vitro studies, fludrocortisone enhanced CXCR4 and CD62L expression, which was counteracted by spironolactone. Incubation of naïve T cells with spironolactone alone reduced CD62L and CCR7 expression. Our results indicate a regulatory influence of MR signaling on human T‐cell migration and suggest a role for endogenous aldosterone in the redistribution of T‐cell subsets to lymph nodes, involving CD62L, CCR7, and CXCR4. Facilitation of T‐cell homing following sleep‐dependent aldosterone release might thus essentially contribute to sleep's well‐known role in supporting adaptive immunity.