bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of DEM generation accuracy from UAS imagery
Authors: Santise M. , Fornari M. , Forlani G. , Roncella R.
Published: June 2014

Abstract. The growing use of UAS platform for aerial photogrammetry comes with a new family of Computer Vision highly automated processing software expressly built to manage the peculiar characteristics of these blocks of images. It is of interest to photogrammetrist and professionals, therefore, to find out whether the image orientation and DSM generation methods implemented in such software are reliable and the DSMs and orthophotos are accurate. On a more general basis, it is interesting to figure out whether it is still worth applying the standard rules of aerial photogrammetry to the case of drones, achieving the same inner strength and the same accuracies as well. With such goals in mind, a test area has been set up at the University Campus in Parma. A large number of ground points has been measured on natural as well as signalized points, to provide a comprehensive test field, to check the accuracy performance of different UAS systems. In the test area, points both at ground-level and features on the buildings roofs were measured, in order to obtain a distributed support also altimetrically. Control points were set on different types of surfaces (buildings, asphalt, target, fields of grass and bumps); break lines, were also employed. The paper presents the results of a comparison between two different surveys for DEM (Digital Elevation Model) generation, performed at 70 m and 140 m flying height, using a Falcon 8 UAS.
Image based 3D city modeling : Comparative study
Authors: Singh S.P. , Jain K. , Mandla V.R.
Published: June 2014

Abstract. 3D city model is a digital representation of the Earth’s surface and it’s related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India). This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can’t do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good result. For Large city reconstruction; CityEngine is a good product. Agisoft Photoscan software creates much better 3D model with good texture quality and automatic processing. So this image based comparative study is useful for 3D city user community. Thus this study will provide a good roadmap for geomatics user community to create photo-realistic virtual 3D city model by using image based techniques.
The sanctuary of Punta Stilo at Kaulonia-Monasterace (Rc, Italy): preliminary results of the close range photogrammetric surveys 2012-2013
Authors: Taccola E. , Parra M. C. , Ampolo C.
Published: June 2014

Abstract. During the 2012–2013 excavations at the Sanctuary of Punta Stilo at Kaulonia, carried out by the University of Pisa and the Scuola Normale Superiore of Pisa, close range aerial and terrestrial photogrammetric surveys were tested for the first time. The aim of the test was to verify the accuracy of the site planimetry currently used, dating back also to a century ago. The 3D data obtained have allowed new data to be acquired for correcting and updating the mapping of the site.
UAV-based photogrammetry: monitoring of a building zone
Authors: Unger J. , Reich M. , Heipke C.
Published: June 2014

Abstract. The use of small-size unmanned aerial vehicles (UAV) for civil applications in many different fields such as archaeology, disaster monitoring, aerial surveying or mapping has significantly increased in recent years. The high flexibility and the low cost per acquired information compared to classical systems – terrestrial or aerial – offer a high variety of different applications. This paper addresses the photogrammetric analysis of a monitoring project and gives an insight into the potential of UAV using low cost sensors and present-day processing software. The area of interest is the "zero:e-park", a building zone of zero emission housing in Hannover, Germany, that we monitored in three different epochs over a period of five months. We show that we can derive three dimensional information with an accuracy of a few centimetres. Changes during the epochs, also small ones like the dismantling of scaffolding can be detected. We also depict the limitations of the DEM generation approach which occur at sharp edges and height jumps as well as repetitive structure. Additionally, we compare two different commercial software packages which reveals that some systematic errors still remain in the results.
Generation of effective orthophotos for road surfaces using MMS
Authors: Yagishita D. , Chikatsu H.
Published: June 2014

Abstract. In recent years, high precision and high resolution road surface orthophotos have been generated using video cameras mounted on surveying vehicles. However, there is a serious issue in generating an orthophoto from this image. The shadows of the surrounding structures and vehicles on the road surface cause a lack of information and decrease in visibility. Therefore, the shadows should be removed from the images for exact road management. On the other hand, the Mobile Mapping System with a laser scanner mounted on vehicles has been receiving more attention because the laser scanner intensity is almost unaffected by shadows. This paper presents shadow extraction and shadow correction for generating road surface orthophotos using the laser scanner intensity.
A real-time photogrammetry system based on embedded architecture
Authors: Zheng S. Y. , Gui L. , Wang X. N. , Ma D.
Published: June 2014

Abstract. In order to meet the demand of real-time spatial data processing and improve the online processing capability of photogrammetric system, a kind of real-time photogrammetry method is proposed in this paper. According to the proposed method, system based on embedded architecture is then designed: using FPGA, ARM+DSP and other embedded computing technology to build specialized hardware operating environment, transplanting and optimizing the existing photogrammetric algorithm to the embedded system, and finally real-time photogrammetric data processing is realized. At last, aerial photogrammetric experiment shows that the method can achieve high-speed and stable on-line processing of photogrammetric data. And the experiment also verifies the feasibility of the proposed real-time photogrammetric system based on embedded architecture. It is the first time to realize real-time aerial photogrammetric system, which can improve the online processing efficiency of photogrammetry to a higher level and broaden the application field of photogrammetry.
Automatic Classification of coarse density LiDAR data in urban area
Authors: Badawy H.M. , Moussa A. , El-Sheimy N.
Published: June 2014

Abstract. The classification of different objects in the urban area using airborne LIDAR point clouds is a challenging problem especially with low density data. This problem is even more complicated if RGB information is not available with the point clouds. The aim of this paper is to present a framework for the classification of the low density LIDAR data in urban area with the objective to identify buildings, vehicles, trees and roads, without the use of RGB information. The approach is based on several steps, from the extraction of above the ground objects, classification using PCA, computing the NDSM and intensity analysis, for which a correction strategy was developed. The airborne LIDAR data used to test the research framework are of low density (1.41 pts/m2) and were taken over an urban area in San Diego, California, USA. The results showed that the proposed framework is efficient and robust for the classification of objects.
A feasibility study on the measurement of tree trunks in forests using multi-scale vertical images
Authors: Berveglieri A. , Oliveira R. O. , Tommaselli A. M.G.
Published: June 2014

Abstract. The determination of the Diameter at Breast Height (DBH) is an important variable that contributes to several studies on forest, e.g., environmental monitoring, tree growth, volume of wood, and biomass estimation. This paper presents a preliminary technique for the measurement of tree trunks using terrestrial images collected with a panoramic camera in nadir view. A multi-scale model is generated with these images. Homologue points on the trunk surface are measured over the images and their ground coordinates are determined by intersection of rays. The resulting XY coordinates of each trunk, defining an arc shape, can be used as observations in a circle fitting by least squares. Then, the DBH of each trunk is calculated using an estimated radius. Experiments were performed in two urban forest areas to assess the approach. In comparison with direct measurements on the trunks taken with a measuring tape, the discrepancies presented a Root Mean Square Error (RMSE) of 1.8 cm with a standard deviation of 0.7 cm. These results demonstrate compatibility with manual measurements and confirm the feasibility of the proposed technique.
Numerical investigation of stability of breather-type solutions of the nonlinear Schrödinger equation
Authors: Calini A. , Schober C. M.
Published: June 2014

Abstract. In this article we conduct a broad numerical investigation of stability of breather-type solutions of the nonlinear Schrödinger (NLS) equation, a widely used model of rogue wave generation and dynamics in deep water. NLS breathers rising over an unstable background state are frequently used to model rogue waves. However, the issue of whether these solutions are robust with respect to the kind of random perturbations occurring in physical settings and laboratory experiments has just recently begun to be addressed. Numerical experiments for spatially periodic breathers with one or two modes involving large ensembles of perturbed initial data for six typical random perturbations suggest interesting conclusions. Breathers over an unstable background with N unstable modes are generally unstable to small perturbations in the initial data unless they are "maximal breathers" (i.e., they have N spatial modes). Additionally, among the maximal breathers with two spatial modes, the one of highest amplitude due to coalescence of the modes appears to be the most robust. The numerical observations support and extend to more realistic settings the results of our previous stability analysis, which we hope will provide a useful tool for identifying physically realizable wave forms in experimental and observational studies of rogue waves.
The slope seismic response monitoring of Wenchuan aftershocks in Qingchuan
Authors: Luo Y. H. , Huang R. , Wang Y.
Published: June 2014

Abstract. This work reports some new progress of rock slope inside seismic response monitoring results in the area of Mountain Dong and Mountain Shizi (Qingchuan county), located more than 250 km NE of Yingxiu epicenter (2008 Wenchuan earthquake), Sichuan province. Five adits with the maximum depth of 15 m had been excavated in different elevation on both sides slope. Stations were emplaced at middle of the adits, from September 2009 to May 2010 more than 60 Wenchuan aftershocks had been monitored, 22 typical aftershocks had been analysis, whose magnitude varied between 2.3 ~ 5.2 and epicentral distance was from a few to 45 km. A comparison analysis of recordings provided evidence of the presence amplification effect at the Q4 station of Mt. Dong, which the peak horizontal acceleration amplification factor is between 1.0 ~ 2.5. But this amplification effect had no stronger at other stations. Comprehensive studies show that the relative height to riverbed is an important factor of Q4 seismic amplification effect. Otherwise the topography of Q4 site is conducive to horizontal amplification, not the vertical amplification. Moreover the calculation of Arias intensity (Ia) had the same amplification effect as the PGA, only the amplification factor is between 1.0 ~ 3.47 much bigger than the latter. On the other hand, the calculation of horizontal to vertical spectral ratio (HVSR) at Q4 shows the curves have multiple peaks corresponding with different dominant frequencies, which the amplification factor is always bigger than other stations at Mt. Dong. Sufficient evidence indicates that the Mt. Dong amplification effect is stronger than Mt. Shizi.
Usefulness of Non-Linear Input—Output Models for Economic Impact Analyses in Tourism and Recreation
Authors: Klijs Jeroen , Peerlings Jack , Heijman Wim
Published: June 2014

In tourism and recreation management it is still common practice to apply traditional input–output (IO) economic impact models, despite their well-known limitations. In this study the authors analyse the usefulness of applying a non-linear input–output (NLIO) model, in which price-induced input substitution is accounted for. For large changes in final demand, a NLIO model is more useful than a traditional IO model, leading to higher or lower impacts. For small changes in final demand input substitution is less likely. In that case the application of the NLIO may lead to the same results as a traditional IO model. To analyse changes of subsidies, a traditional IO model is not an option. A more flexible model, such as the NLIO, is required. The NLIO model forces researchers to make choices about capacity constraints, factor mobility and the substitution elasticity, which can be difficult but create flexibility and allow for more realism.
Exogenous Ascorbic Acid and Glutathione Alleviate Oxidative Stress Induced by Salt Stress in the Chloroplasts of Oryza sativa L.
Authors: Wang Renlei , Liu Shaohua , Zhou Feng , Ding Chunxia
Published: June 2014

The effects of exogenous ascorbic acid (AsA) and reduced glutathione (GSH) on antioxidant enzyme activities [superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR)] and the contents of malondialdehyde (MDA) and H2O2, as well as of endogenous AsA and GSH, in the chloroplasts of two rice cultivars, the salt-tolerant cultivar Pokkali and the salt-sensitive cultivar Peta, were investigated. Exogenous AsA and GSH enhanced SOD, APX, and GR activities, increased endogenous AsA and GSH contents, and reduced those of H2O2 and MDA in the chloroplasts of both cultivars under salt stress (200 mM NaCl), but the effects were significantly more pronounced in cv. Pokkali. GSH acted more strongly than AsA on the plastidial reactive oxygen scavenging systems. These results indicated that exogenous AsA and GSH differentially enhanced salinity tolerance and alleviated salinity-induced damage in the two rice cultivars
Preparation of PVDF UF Membranes under an External Electric Field with PVP as Additive
Authors: Shi Baoli , He Jing
Published: June 2014

In this study, PVDF UF membranes were prepared with PVP as additive via a favorable method of applying high voltage external electric field (2kV) through the immersion precipitation phase inversion process. The influence of external electric field on the structure, surface functional groups, membrane potential, and surface hydrophilicity of the membranes were researched. In addition, anti-fouling property and separation performance of the membranes were also investigated. The results indicated that the protein adsorption amount on the electric treated membranes was distinctly reduced. Especially for the electric treated PVDF membrane with PVP K70 as additive, the value of water contact angle reached 75.4° and the protein adsorption amount decreased 76 %, reaching 20.39 µg·cm-2. The separation performance of the electric treated membrane was also superior to that of the un-treated membrane. All the experimental results indicated that this electric treated approach open a promising way for the modification of PVDF membrane because it combined membrane preparation and modification in only one physical step without additional chemical reagents.
Preparation and Characterization of Superhydrophobic Modification of Polyvinylidene Fluoride Membrane by Dip-Coating
Authors: Zhang YuZhong , Li YingNa , Zhang HuaFeng , Ye Hui , Chen Ying , Li Yue
Published: June 2014

The superhydrophobicity polyvinylidene fluoride (PVDF) membranes were modified via reducing surface energy by dip-coating perfluoroalkyl methacrylic copolymer (Zonyl 8740) onto the membranes prepared on mat glass. The chemical component of the unmodified and modified PVDF membranes surface was investigated by ATR-FTIR. Morphology and hydrophobicity of the unmodified and modified PVDF membranes were examined by scanning electronic microscopy and water contact angle, respectively. The effects of concentration of Zonyl 8740, coating time, conditions of heat treatment on hydrophobic capability of PVDF membranes were investigated. The results showed that the water contact angle increased from 141˚ to 151˚ by the dip-coating modification, therefore getting superhydrophobic PVDF membrane. Moreover, the porosity and the morphology of modified PVDF membrane were unchanged by the dip-coating modification. This results suggested that the hydrophobicty stability of the modified PVDF membrane was also good.
Solar wind pressure pulse‐driven magnetospheric vortices and their global consequences
Authors: Shi Q. Q. , Hartinger M.D. , Angelopoulos V. , Tian A.M. , Fu S.Y. , Zong Q.‐G. , Weygand J. M. , Raeder J. , Pu Z.Y. , Zhou X.Z. , Dunlop M.W. , Liu W.L. , Zhang H. , Yao Z.H. , Shen X.C.
Published: June 2014

We report the in situ observation of a plasma vortex induced by a solar wind dynamic pressure enhancement in the nightside plasma sheet using multipoint measurements from Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellites. The vortex has a scale of 5–10 Re and propagates several Re downtail, expanding while propagating. The features of the vortex are consistent with the prediction of the Sibeck (1990) model, and the vortex can penetrate deep (~8 Re) in the dawn‐dusk direction and couple to field line oscillations. Global magnetohydrodynamics simulations are carried out, and it is found that the simulation and observations are consistent with each other. Data from THEMIS ground magnetometer stations indicate a poleward propagating vortex in the ionosphere, with a rotational sense consistent with the existence of the vortex observed in the magnetotail.
A tailward moving current sheet normal magnetic field front followed by an earthward moving dipolarization front
Authors: Hwang K.‐J. , Goldstein M. L. , Moore T. E. , Walsh B. M. , Baishev D. G. , Moiseyev A. V. , Shevtsov B. M. , Yumoto K.
Published: June 2014

A case study is presented using measurements from the Cluster spacecraft and ground‐based magnetometers that show a substorm onset propagating from the inner to outer plasma sheet. On 3 October 2005, Cluster, traversing an ion‐scale current sheet at the near‐Earth plasma sheet, detected a sudden enhancement of Bz, which was immediately followed by a series of flux rope structures. Both the local Bz enhancement and flux ropes propagated tailward. Approximately 5 min later, another Bz enhancement, followed by a large density decrease, was observed to rapidly propagate earthward. Between the two Bz enhancements, a significant removal of magnetic flux occurred, possibly resulting from the tailward moving Bz enhancement and flux ropes. In our scenario, this flux removal caused the magnetotail to be globally stretched so that the thinnest sheet formed tailward of Cluster. The thinned current sheet facilitated magnetic reconnection that quickly evolved from plasma sheet to lobe and generated the later earthward moving dipolarization front (DF) followed by a reduction in density and entropy. Ground magnetograms located near the meridian of Cluster's magnetic foot points show two‐step bay enhancements. The positive bay associated with the first Bz enhancement indicates that the substorm onset signatures propagated from the inner to the outer plasma sheet, consistent with the Cluster observation. The more intense bay features associated with the later DF are consistent with the earthward motion of the front. The event suggests that current disruption signatures that originated in the near‐Earth current sheet propagated tailward, triggering or facilitating midtail reconnection, thereby preconditioning the magnetosphere for a later strong substorm enhancement.
Geotail observation of upper band and lower band chorus elements in the outer magnetosphere
Authors: Yagitani Satoshi , Habagishi Toshihiro , Omura Yoshiharu
Published: June 2014

Using the Geotail observation of upper band and lower band (dual‐band) rising tone chorus emissions in the dayside outer magnetosphere, we evaluate the mechanism of creating their frequency gap bandwidths, on the basis of a nonlinear damping mechanism at half the local gyrofrequency proposed by Omura et al. (2009). For ELF dual‐band chorus elements observed in the dayside of the equatorial outer magnetosphere (L ∼ 10.5), the lower cutoff frequency of the upper band elements follows half the local gyrofrequency. On the other hand, the upper cutoff of the lower band elements is almost consistent with half the gyrofrequency at a minimum‐B pocket (a possible chorus generation region) along the field lines connecting Geotail according to the Tsyganenko geomagnetic TS05 model. This is consistent with the scenario that the rising tone wave packet initially excited in a wide frequency range suffers from damping at half the local gyrofrequencies during quasi‐parallel propagation. Since the local gyrofrequency gradually increases away from the generation region, the upper cutoff of a lower band element should represent half the gyrofrequency at the generation region, whereas the lower cutoff of an upper band element should follow half the local gyrofrequency. We confirm that the frequency sweep rates and amplitudes of the observed chorus wave packets are consistent with those predicted by the nonlinear growth theory of chorus emissions, except for the frequency gap. This indicates an observational evidence of nonlinear chorus generation in the minimum‐B pocket in the outer magnetosphere and creation of dual‐band elements due to nonlinear damping through quasi‐parallel wave propagation.
The role of tributary relative timing and sequencing in controlling large floods
Authors: Pattison Ian , Lane Stuart N. , Hardy Richard J. , Reaney Sim M.
Published: June 2014

Hydrograph convolution is a product of tributary inputs from across the watershed. The time‐space distribution of precipitation, the biophysical processes that control the conversion of precipitation to runoff and channel flow conveyance processes, are heterogeneous and different areas respond to rainfall in different ways. We take a subwatershed approach to this and account for tributary flow magnitude, relative timing, and sequencing. We hypothesize that as the scale of the watershed increases so we may start to see systematic differences in subwatershed hydrological response. We test this hypothesis for a large flood (T > 100 years) in a large watershed in northern England. We undertake a sensitivity analysis of the effects of changing subwatershed hydrological response using a hydraulic model. Delaying upstream tributary peak flow timing to make them asynchronous from downstream subwatersheds reduced flood magnitude. However, significant hydrograph adjustment in any one subwatershed was needed for meaningful reductions in stage downstream, although smaller adjustments in multiple tributaries resulted in comparable impacts. For larger hydrograph adjustments, the effect of changing the timing of two tributaries together was lower than the effect of changing each one separately. For smaller adjustments synergy between two subwatersheds meant the effect of changing them together could be greater than the sum of the parts. Thus, this work shows that while the effects of modifying biophysical catchment properties diminishes with scale due to dilution effects, their impact on relative timing of tributaries may, if applied in the right locations, be an important element of flood management.
An empirical model for the plasma environment along Titan's orbit based on Cassini plasma observations
Authors: Smith H. Todd , Rymer Abigail M.
Published: June 2014

Prior to Cassini's arrival at Saturn, the nitrogen‐rich dense atmosphere of Titan was considered as a significant, if not dominant, source of heavy ions in Saturn's magnetosphere. While nitrogen was detected in Saturn's magnetosphere based on Cassini observations, Enceladus instead of Titan appears to be the primary source. However, it is difficult to imagine that Titan's dense atmosphere is not a source of nitrogen. In this paper, we apply the Rymer et al.'s (2009) Titan plasma environment categorization model to the plasma environment along Titan's orbit when Titan is not present. We next categorize the Titan encounters that occurred since Rymer et al. (2009). We also produce an empirical model for applying the probabilistic occurrence of each plasma environment as a function of Saturn local time (SLT). Finally, we summarized the electron energy spectra in order to allow one to calculate more accurate electron‐impact interaction rates for each plasma environment category. The combination of this full categorization versus SLT and empirical model for the electron spectrum is critical for understanding the magnetospheric plasma and will allow for more accurate modeling of the Titan plasma torus.
In situ signatures of residual plasmaspheric plumes: Observations and simulation
Authors: Goldstein J. , Thomsen M. F. , DeJong A.
Published: June 2014

We compare in situ observations of the Los Alamos National Laboratory (LANL) Magnetospheric Plasma Analyzers with output of a dynamic, plasmapause test particle (PTP) simulation for the moderately disturbed interval 18–20 January 2000. In the model, weakly enhanced convection on 18 January creates a narrow drainage plume (plume A) that wraps completely around the main torus. Moderate convection on 19 January triggers significant plasmaspheric erosion, forming a second plume (B) that coexists with the narrow, wrapped, residual plume A. We fly three virtual LANL satellites through the simulation domain. The observations are globally consistent with the PTP simulation; LANL data contain several intervals of plume plasma in the model's predicted magnetic local time (MLT) sector. The modeled durations of plume sector transits are in good agreement with the LANL data. On a subglobal scale, the MLT widths and timings of the simulated plumes do not precisely agree with observations. However, several observation intervals exhibit good morphological agreement with virtual spacecraft signatures of two distinct, coexisting plumes (A and B). The fine‐scale structure in the PTP model arises from the merging of residual plume A with the newer plume B. Plume merging is one theoretical means of generating fine structure in the plasmasphere: during multiple cycles of erosion and recovery, successive layers of wrapped, residual plumes can merge with newer plumes, creating layers of filamentary density structure. The model‐data comparisons suggest that the plasmaspheric density distribution may preserve some memory of prior epochs of erosion and recovery.
The Experimental Thermochemistry of Metal Phenolates
Authors: Slayden Suzanne W. , Liebman Joel F.
Published: June 2014

The current study concerns the thermochemistry of metal phenolates wherein the metal is bound to the oxygen by a σ bond, or is part of an ionic solid salt or ion pairs in solution. The main quantities that are discussed are enthalpies of formation and of binding, equilibrium and stability constants. The discussion is organized by increasing atomic number of the metals, starting with lithium and ending with the actinides. Complete coverage is not intended, but at least one rationalized thermochemical example for each metal is given, where such data exists.
Coordination Chemistry of Metal Phenolates—General Aspects
Authors: H. Doerrer Linda
Published: June 2014

An overview of metal phenolate chemistry is given that highlights the structural and functional diversity of contemporary chemistry between metals from all parts of the periodic table and aryloxide ligands. After a brief overview of synthetic methods, the review is organized using structural characterization, but is not exclusive of non‐structurally characterized species. Monodentate and polydentate ligands are described and organized by the type and number of donor atoms. Within each section, the chemistry is further subdivided by the periodic table s‐, p‐, d‐, and f‐blocks. Extensive references to the literature are provided for the interested reader.
Coordination Chemistry and Applications of Nitrilotris(N‐Methylenephenoxy)–Metal Complexes
Authors: Miriam Mba , Cristiano Zonta , Giulia Licini
Published: June 2014

Nitrilotris(N‐methylenephenols), commonly called triphenolamines (TPA), are highly modular, tetradentate molecules that effectively coordinate to transition metals and main group elements with podand topology. They form chiral complexes with intrinsically well‐defined geometries (pentacoordinate trigonal bipyramidal, hexacoordinate octahedral, and, more rarely, trigonal monopyramidal geometries) controlled by the ligand. Nitrilotris(N‐methylenephenoxy)–metal complexes have been found to be effective and robust catalysts in a series of important processes like polymerizations (titanium(IV), zirconium(VI), hafnium(VI), germanium(VI), and vanadium(V) complexes), oxygen transfer reactions (titanium(VI), vanadium(V), molybdenum(VI), and nickel(II) complexes), carbon–carbon bond formation (aluminium(III), and titanium(VI) complexes), carbon dioxide fixation (iron(III) complexes), and metathesis (Mo(VI) complexes).
Student Veteran Discussion Panels: Deconstructing the Traumatized Veteran Stigma on Campus
Authors: Osborne Nicholas J.
Published: June 2014

Nicholas J. Osborne describes a series of discussion panels held at the University of Illinois at Urbana–Champaign that helped the campus community learn more about the varied experiences of the student veterans in their midst and supported the student veterans in having a positive voice on campus.
Functional Impairments Characterizing Mild, Moderate, and Severe Hallux Valgus
Authors: Hurn Sheree E. , Vicenzino Bill , Smith Michelle D.
Published: June 2014

Objective

Hallux valgus (HV) has been linked to functional disability and increased risk of falls, but mechanisms underpinning functional disability are unclear. This study investigated functional performance, muscle strength, and plantar pressures in adults with mild, moderate, and severe HV compared to controls, while considering the influence of foot pain.

Methods

Sixty adults with HV (classified as mild, moderate, and severe on dorsalplantar radiographs) and 30 controls participated. Measures included hallux plantar flexion and abduction strength, walking performance, postural sway, and forefoot plantar pressures. Multivariate analysis of covariance and pairwise comparisons (P < 0.05 after Bonferroni adjustment) were used to investigate differences between groups, adjusting for age, sex, body mass index, and foot pain.

Results

Hallux plantar flexion and abduction strength were significantly reduced in those with moderate (mean differences: plantar flexion −45.8 N, abduction −12.3 N; P < 0.001) and severe HV (plantar flexion −50.1 N; P < 0.001, abduction −11.2 N; P = 0.01) compared to controls. A significant reduction in hallux peak pressure and pressure‐time integral was evident in moderate (peak pressure −90.8 kPa; P < 0.001) and severe HV (peak pressure −106.2 kPa; P < 0.001) compared to controls. Those with severe HV also demonstrated increased mediolateral postural sway in single leg stance compared to controls (3.5 cm; P = 0.01).

Conclusion

Moderate to severe HV is associated with reduced hallux plantar pressures and strength measures, while relatively normal function compared to controls was found in those with mild deformity. Greater understanding of specific functional deficits associated with different stages of HV will help inform clinical management and future research.
Two‐Dimensional Mott Insulators in SrVO3 Ultrathin Films
Authors: Gu Man , Wolf Stuart A. , Lu Jiwei
Published: June 2014

Strongly correlated oxides that undergo a metal‐insulator transition (MIT) are a subject of great current interest for their potential application to future electronics as switches and sensors. Recent advances in thin film technology have opened up new avenues to tailor MIT for novel devices beyond conventional CMOS scaling. Here, dimensional‐crossover‐driven MITs are demonstrated in high‐quality epitaxial SrVO3 (SVO) thin films grown by a pulsed electron‐beam deposition technique. Thick SVO films (∼25 nm) exhibit metallic behavior with the electrical resistivity following the T2 law corresponding to a Fermi liquid system. A temperature driven MIT is induced in SVO ultrathin films with thicknesses below 6.5 nm. The transition temperature TMIT is at 50 K for the 6.5 nm film, 120 K for the 5.7 nm film and 205 K for the 3 nm film. The emergence of the observed MIT can be attributed to the dimensional crossover from a three‐dimensional metal to a two‐dimensional Mott insulator, as the resulting reduction in the effective bandwidth W opens a band gap at the Fermi level. The magneto‐transport study of the SVO ultrathin films also confirm the observed MIT is due to the electron‐electron interactions other than disorder‐induced localization.
Arterial stiffness, oxidative stress, and smoke exposure in wildland firefighters
Authors: Gaughan Denise M. , Siegel Paul D. , Hughes Michael D. , Chang Chiung‐Yu , Law Brandon F. , Campbell Corey R. , Richards Jennifer C. , Kales Stefanos F. , Chertok Marcia , Kobzik Lester , Nguyen Phuong‐son , O'Donnell Carl R. , Kiefer Max , Wagner Gregory R. , Christiani David C.
Published: June 2014

Objectives

To assess the association between exposure, oxidative stress, symptoms, and cardiorespiratory function in wildland firefighters.

Methods

We studied two Interagency Hotshot Crews with questionnaires, pulse wave analysis for arterial stiffness, spirometry, urinary 8‐iso‐prostaglandin F2α (8‐isoprostane) and 8‐hydroxy‐2'‐deoxyguanosine (8‐OHdG), and the smoke exposure marker (urinary levoglucosan). Arterial stiffness was assessed by examining levels of the aortic augmentation index, expressed as a percentage. An oxidative stress score comprising the average of z‐scores created for 8‐OHdG and 8‐isoprostane was calculated.

Results

Mean augmentation index % was higher for participants with higher oxidative stress scores after adjusting for smoking status. Specifically for every one unit increase in oxidative stress score the augmentation index % increased 10.5% (95% CI: 2.5, 18.5%). Higher mean lower respiratory symptom score was associated with lower percent predicted forced expiratory volume in one second/forced vital capacity.

Conclusions

Biomarkers of oxidative stress may serve as indicators of arterial stiffness in wildland firefighters. Am. J. Ind. Med. 57:748–756, 2014. © 2014 Wiley Periodicals, Inc.
A Strategy Utilizing a Recyclable Macrocycle Transporter for the Efficient Synthesis of a Triazolium‐Based [2]Rotaxane
Authors: Chao Sovy , Romuald Camille , Fournel‐Marotte Karine , Clavel Caroline , Coutrot Frédéric
Published: June 2014

A general synthesis of triazolium‐containing [2]rotaxanes, which could not be accessed by other methods, is reported. It is based on a sequential strategy starting from a well‐designed macrocycle transporter which contains a template for dibenzo‐24‐crown‐8 and a N‐hydroxysuccinimide (NHS) moiety. The sequence is: 1) synthesis by slippage of a [2]rotaxane building‐block; 2) its elongation at its NHS end; 3) the delivery of the macrocycle to the elongated part of the axle by an induced translational motion; 4) the contraction process to yield the targeted [2]rotaxane and recycle the initial transporter.
Supramolecular Luminescent Lanthanide Dimers for Fluoride Sequestering and Sensing
Authors: Liu Tao , Nonat Aline , Beyler Maryline , Regueiro‐Figueroa Martín , Nchimi Nono Katia , Jeannin Olivier , Camerel Franck , Debaene François , Cianférani‐Sanglier Sarah , Tripier Raphaël , Platas‐Iglesias Carlos , Charbonnière Loïc J.
Published: June 2014

Lanthanide complexes (Ln=Eu, Tb, and Yb) that are based on a C2‐symmetric cyclen scaffold were prepared and characterized. The addition of fluoride anions to aqueous solutions of the complexes resulted in the formation of dinuclear supramolecular compounds in which the anion is confined into the cavity that is formed by the two complexes. The supramolecular assembly process was monitored by UV/Vis absorption, luminescence, and NMR spectroscopy and high‐resolution mass spectrometry. The X‐ray crystal structure of the europium dimer revealed that the architecture of the scaffold is stabilized by synergistic effects of the EuFEu bridging motive, π stacking interactions, and a four‐component hydrogen‐bonding network, which control the assembly of the two [EuL] entities around the fluoride ion. The strong association in water allowed for the luminescence sensing of fluoride down to a detection limit of 24 nM.
Brief Report: Granulocyte–Macrophage Colony‐Stimulating Factor Drives Monosodium Urate Monohydrate Crystal–Induced Inflammatory Macrophage Differentiation and NLRP3 Inflammasome Up‐Regulation in an In Vivo Mouse Model
Authors: Shaw Odette M. , Steiger Stefanie , Liu Xiao , Hamilton John A. , Harper Jacquie L.
Published: June 2014

Objective

To determine the role of granulocyte–macrophage colony‐stimulating factor (GM‐CSF) in the differentiation of inflammatory macrophages in an in vivo model of monosodium urate monohydrate (MSU) crystal–induced inflammation.

Methods

C57BL/6J mice were treated with either clodronate liposomes to deplete peritoneal macrophages or GM‐CSF antibody and were then challenged by intraperitoneal injection of MSU crystals. Peritoneal lavage fluid was collected, and cellular infiltration was determined by flow cytometry. Purified resident and MSU crystal–recruited monocyte/macrophages were stimulated ex vivo with MSU crystals. The interleukin‐1β (IL‐1β) levels in lavage fluids and ex vivo assay supernatants were measured. GM‐CSF–derived and macrophage colony‐stimulating factor (M‐CSF)–derived macrophages were generated in vitro from bone marrow cells. Protein expression of IL‐1β, caspase 1, NLRP3, and ASC by in vitro– and in vivo–generated monocyte/macrophages was analyzed by Western blotting.

Results

Depletion of resident macrophages lowered MSU crystal–induced IL‐1β and GM‐CSF levels in vivo as well as IL‐1β production by MSU crystal–recruited monocytes stimulated ex vivo. GM‐CSF neutralization in vivo decreased MSU crystal–induced IL‐1β levels and neutrophil infiltration. MSU crystal–recruited monocyte/macrophages from GM‐CSF–neutralized mice expressed lower levels of the macrophage marker CD115 and produced less IL‐1β following ex vivo stimulation. These monocytes exhibited decreased expression of NLRP3, pro/active IL‐1β, and pro/active caspase 1. In vitro–derived GM‐CSF–differentiated macrophages expressed higher levels of NLRP3, pro/active IL‐1β, and pro/active caspase 1 compared to M‐CSF–differentiated macrophages.

Conclusion

GM‐CSF plays a key role in the differentiation of MSU crystal–recruited monocytes into proinflammatory macrophages. GM‐CSF production may therefore contribute to the exacerbation of inflammation in gout.
Distinct Effects of Methotrexate and Etanercept on the B Cell Compartment in Patients With Juvenile Idiopathic Arthritis
Authors: Glaesener Stephanie , Quách Tâm D. , Onken Nils , Weller‐Heinemann Frank , Dressler Frank , Huppertz Hans‐Iko , Thon Angelika , Meyer‐Bahlburg Almut
Published: June 2014

Objective

B cells have been shown to play an important role in the pathogenesis of rheumatoid arthritis and juvenile idiopathic arthritis (JIA). Current treatments include the disease‐modifying antirheumatic drugs methotrexate (MTX) and tumor necrosis factor α inhibition with etanercept. This study was undertaken to determine how these drugs influence the B cell compartment in patients with JIA.

Methods

B cell subpopulations and follicular helper T (Tfh) cells in the peripheral blood of JIA patients were investigated by multicolor flow cytometry. Serum immunoglobulin and BAFF levels were determined by enzyme‐linked immunosorbent assay.

Results

There was a significant decrease in transitional B cells and significantly lower serum immunoglobulin levels in patients receiving MTX than in untreated patients and those receiving etanercept. In contrast, etanercept treatment had no effect on most of the B cell subpopulations, but resulted in significantly lower BAFF levels and increased numbers of Tfh cells. Thus, our findings indicate an unexpected and previously unknown direct effect of low‐dose MTX on B cells, whereas etanercept had a more indirect influence.

Conclusion

Our results contribute to a better understanding of the potency of MTX in autoantibody‐mediated autoimmune disease and present a possible mechanism of prevention of the development of drug‐induced antibodies to biologic agents. The finding that MTX and etanercept affect the B cell compartment differently supports the notion that combination therapy with etanercept and MTX is more effective than monotherapy.
Oxidative Demethylation of DNA and RNA Mediated by Non‐Heme Iron‐Dependent Dioxygenases
Authors: Lu Lining , Zhu Chenxu , Xia Bo , Yi Chengqi
Published: June 2014

DNA/RNA methylation can be generated by methyltransferases and thus plays a critical role in regulating cellular processes; alternatively, nucleic acid methylation can be produced by methylation agents and is cytotoxic/mutagenic if left unrepaired. Oxidative demethylation mediated by non‐heme iron‐dependent dioxygenases is an efficient way to reverse either the cellular roles of regulatory methylation or the cytotoxic/mutagenic effects of methylation damage. In this Focus Review we summarize recent advances in the study of nucleic acid dioxygenases exemplified by the TET and AlkB family proteins, with an emphasis on chemical insights from the recent literature. Comparison of the chemical mechanisms of these dioxygenases revealed that differences in the mechanism also contribute significantly to their distinct biological functions.
Effects of licochalcone A on the bioavailability and pharmacokinetics of nifedipine in rats: possible role of intestinal CYP3A4 and P‐gp inhibition by licochalcone A
Authors: Choi Jin‐Seok , Choi Jun‐Shik , Choi Dong‐Hyun
Published: June 2014

The purpose of this study was to investigate the possible effects of licochalcone A (a herbal medicine) on the pharmacokinetics of nifedipine and its main metabolite, dehydronifedipine, in rats. The pharmacokinetic parameters of nifedipine and/or dehydronifedipine were determined after oral and intravenous administration of nifedipine to rats in the absence (control) and presence of licochalcone A (0.4, 2.0 and 10 mg/kg). The effect of licochalcone A on P‐glycoprotein (P‐gp) and cytochrome P450 (CYP) 3A4 activity was also evaluated. Nifedipine was mainly metabolized by CYP3A4. Licochalcone A inhibited CYP3A4 enzyme activity in a concentration‐dependent manner with a 50% inhibition concentration (IC50) of 5.9 μm. In addition, licochalcone A significantly enhanced the cellular accumulation of rhodamine‐123 in MCF‐7/ADR cells overexpressing P‐gp. The area under the plasma concentration–time curve from time 0 to infinity (AUC) and the peak plasma concentration (Cmax) of oral nifedipine were significantly greater and higher, respectively, with licochalcone A. The metabolite (dehydronifedipine)–parent AUC ratio (MR) in the presence of licochalcone A was significantly smaller compared with the control group. The above data could be due to an inhibition of intestinal CYP3A4 and P‐gp by licochalcone A. The AUCs of intravenous nifedipine were comparable without and with licochalcone A, suggesting that inhibition of hepatic CYP3A4 and P‐gp was almost negligible. Copyright © 2014 John Wiley & Sons, Ltd.
Simultaneous determination of three dipeptides (JBP485, Gly–Sar and JBP923) in the cell lysates by liquid chromatography‐tandem mass spectrometry: application to identify the function of the PEPT1 transfected cell
Authors: Guo Xinjin , Meng Qiang , Liu Qi , Wang Changyuan , Huo Xiaokui , Zhang Zhe , Kaku Taiichi , Liu Kexin
Published: June 2014

A simple and rapid liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method for the simultaneous determination of JBP485, Gly–Sar and JBP923 in the cell lysates using methanol as a deproteinization solvent was developed and validated. Detection was performed by turbo ionspray ionization in multiple reaction monitoring mode using the transitions of m/z 147.1 → m/z 90.1 for Gly–Sar, m/z 201.1 → m/z 86.1 for JBP485, m/z 219.1 → m/z 86.1 for JBP923 and m/z 152.0 → m/z 110.0 for paracetamol (internal standard). The analytes were separated on a Hypersil ODS C18 HPLC column using isocratic elution mode with a mobile phase containing 0.1% formic acid in water–methanol (97:3, v/v) at a flow rate of 0.2 mL/min. The calibration curves were demonstrated to be linear over the concentration range of 5.00−5000 nm with coefficient of 0.9968 for Gly–Sar, 0.9975 for JBP485 and 0.9952 for JBP923. The intra‐ and inter‐day precisions were <10.2% for each quality contro; level, and the accuracy was within ±5.6% for each analyte. The matrix effect, the extraction recovery and stabilities of LC‐MS/MS analysis were also investigated. This validated method was successfully applied to the simultaneous determination of JBP485, Gly–Sar and JBP923 in the cell lysates for identification of stably transfected HeLa cells with human PEPT1. Copyright © 2014 John Wiley & Sons, Ltd.