bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wetland habitats of the Sabana de Bogotá Andean Highland Plateau and their birds
Authors: Rosselli Loreta , Stiles F. Gary 
Published: March 2012

ABSTRACT

The Sabana de Bogotá highland plateau is located in the eastern Andes wetland complex of Colombia, a biogeographically important and highly degraded area where little is known about the general habitat availability and requirements for wildlife based on comparative studies.
This study sought to identify the environmental factors that best explained the richness and composition of bird communities in the area's wetlands.
GIS and remote images were used to measure landscape and local habitat variables along with the presence of birds in 19 varied wetlands of the Sabana.
A high variation in wetland characteristics, related to their urban or rural status, was found. Aquatic bird richness was associated with wetland area; guilds such as waders that probe in mud, walkers on aquatic vegetation, and shoreline walkers tended to be richer in large wetlands with extensive emergent vegetation cover. Other guilds (waders that wait to stalk, flight feeders and surface swimmers) were more related to open water areas.
It is concluded that the remaining large wetlands should have a high priority for conservation but the set of small natural and artificial wetlands are also important in the maintenance of high habitat heterogeneity, bird populations and regional diversity. Copyright © 2012 John Wiley & Sons, Ltd.
Ethanol‐glycerin fixation with thymol conservation: A potential alternative to formaldehyde and phenol embalming
Authors: Hammer Niels , Löffler Sabine , Feja Christine , Sandrock Mara , Schmidt Wolfgang , Bechmann Ingo , Steinke Hanno 
Published: March 2012

AbstractAnatomical fixation and conservation are required to prevent specimens from undergoing autolysis and decomposition. While fixation is the primary arrest of the structures responsible for autolysis and decomposition, conservation preserves the state of fixation. Although commonly used, formaldehyde has been classified as carcinogenic to humans. For this reason, an adequate substitute was developed. Ethanol‐glycerin fixation and thymol conservation are described and compared with formaldehyde and phenol in this technical report. The setup, tissue qualities, financial aspects, and health concerns of this method are discussed. Ethanol‐glycerin fixation and thymol conservation provide outstanding haptic and optic tissue qualities. Typical formaldehyde and phenol effects, such as skin, airway, and eye irritation, as well as carcinogenic effects, can be circumvented by using ethanol‐glycerin and thymol instead. Ethanol‐glycerin fixation is more expensive than formaldehyde and requires an explosion‐proof facility. However, the absence of health effects and its convincing tissue qualities balance these higher costs. Therefore, ethanol‐glycerin fixation and thymol conservation provide a potential alternative and complement established fixation techniques. The use of carcinogenic formaldehyde and toxic phenol can be effectively restricted through the use of the described method. Anat Sci Educ. © 2012 American Association of Anatomists.
A reliability‐based traffic assignment model for multi‐modal transport network under demand uncertainty
Authors: Fu Xiao , Lam William H. K. , Chen Bi Yu 
Published: March 2012

SUMMARYIn densely populated and congested urban areas, the travel times in congested multi‐modal transport networks are generally varied and stochastic in practice. These stochastic travel times may be raised from day‐to‐day demand fluctuations and would affect travelers' route and mode choice behaviors according to their different expectations of on‐time arrival. In view of these, this paper presents a reliability‐based user equilibrium traffic assignment model for congested multi‐modal transport networks under demand uncertainty. The stochastic bus frequency due to the unstable travel time of bus route is explicitly considered. By the proposed model, travelers' route and mode choice behaviors are intensively explored. In addition, a stochastic state‐augmented multi‐modal transport network is adopted in this paper to effectively model probable transfers and non‐linear fare structures. A numerical example is given to illustrate the merits of the proposed model. Copyright © 2012 John Wiley & Sons, Ltd.
Scheduling highway work zones with genetic algorithm considering the impact of traffic diversion
Authors: Chien Steven I‐Jy , Tang Yimin 
Published: March 2012

SUMMARYHighway work zones caused excessive delay to road users. To reduce user and maintenance costs, work zones shall be designed and scheduled accordingly. An analytical model is developed to jointly optimize work zone lengths and schedule as well as diverted traffic volume for highway maintenance projects, considering time‐varying demand, variable maintenance cost, and various production rates of maintenance crew. With a genetic algorithm, an iterative procedure is developed to search for the optimal solution. A numerical example is illustrated, in which various traffic mitigation plans for a highway maintenance project are evaluated. A sensitivity analysis is conducted, and results indicate the threshold volumes for various conditions (e.g., maintenance crews and capacity of the work zone) at which diverting traffic is desirable. This study demonstrates an effective approach to search for the optimal work zone schedule, which is also applicable to evaluate the effectiveness of traffic diversion plans for a pre‐planned work zone schedule. Copyright © 2012 John Wiley & Sons, Ltd.
Teratogen update: Methotrexate
Authors: Hyoun Sara C. , Običan Sarah G. , Scialli Anthony R. 
Published: March 2012

AbstractMethotrexate and aminopterin are folic acid antagonists that inhibit dihydrofolate reductase, resulting in a block in the synthesis of thymidine and inhibition of DNA synthesis. Methotrexate has been used for the treatment of malignancy, rheumatic disorders, and psoriasis and termination of intrauterine pregnancy. Recently, methotrexate has become a standard treatment for ectopic pregnancy. The misdiagnosis of an intrauterine pregnancy as an ectopic pregnancy can result in exposure of a continuing pregnancy to dose levels of methotrexate of 50 mg/m2 (maternal body surface area). Experimental animal studies have associated methotrexate therapy with embryo death in mice, rats, rabbits, and monkeys. Structural malformations have been most consistently produced in rabbits at a maternal dose level of 19.2 mg/kg. Abnormalities in rabbits include hydrocephalus, microphthalmia, cleft lip and palate, micrognathia, dysplastic sacral and caudal vertebrate, phocomelia, hemimelia, syndactyly, and ectrodactyly. Based on human case reports of methotrexate exposure during pregnancy, a methotrexate embryopathy has been described that includes growth deficiency, microcephaly, hypoplasia of skull bones, wide fontanels, coronal or lambdoidal craniosynostosis, upswept frontal scalp hair, broad nasal bridge, shallow supraorbital ridges, prominent eyes, low‐set ears, maxillary hypoplasia, epicanthal folds, short limbs, talipes, hypodactyly, and syndactyly. This syndrome may be associated with exposures between 6 and 8 weeks after conception and dose levels of 10 mg/week or greater. More recent case reports of methotrexate exposure for the misdiagnosis of ectopic pregnancy involve treatment before 6 weeks after conception and have raised the suggestion of a distinct syndrome due to such early exposures. Tetralogy of Fallot and perhaps other neural crest cell‐related abnormalities may be features of this early syndrome. A disproportionality analysis of methotrexate and aminopterin case reports and series provides support for pulmonary atresia, craniosynostosis, and limb deficiencies as reported more often than expected in methotrexate‐exposed children. Denominator‐based data will be welcome to better define elements of a methotrexate embryopathy and possibly to distinguish an early exposure syndrome from anomalies traditionally associated with methotrexate exposure. Birth Defects Research (Part A), 2012. © 2012 Wiley Periodicals, Inc.
Parametric animation of performance‐captured mesh sequences
Authors: Casas Dan , Tejera Margara , Guillemaut Jean‐Yves , Hilton Adrian 
Published: March 2012

ABSTRACTIn this paper, we introduce an approach to high‐level parameterisation of captured mesh sequences of actor performance for real‐time interactive animation control. High‐level parametric control is achieved by non‐linear blending between multiple mesh sequences exhibiting variation in a particular movement. For example, walking speed is parameterised by blending fast and slow walk sequences. A hybrid non‐linear mesh sequence blending approach is introduced to approximate the natural deformation of non‐linear interpolation techniques whilst maintaining the real‐time performance of linear mesh blending. Quantitative results show that the hybrid approach gives an accurate real‐time approximation of offline non‐linear deformation. An evaluation of the approach shows good performance not only for entire meshes but also with specific mesh areas. Results are presented for single and multi‐dimensional parametric control of walking (speed/direction), jumping (height/distance) and reaching (height) from captured mesh sequences. This approach allows continuous real‐time control of high‐level parameters such as speed and direction whilst maintaining the natural surface dynamics of captured movement. Copyright © 2012 John Wiley & Sons, Ltd.
Antisolvent Precipitation for the Synthesis of Monodisperse Mesoporous Niobium Oxide Spheres as Highly Effective Solid Acid Catalysts
Authors: Li Cheng Chao , Dou Jian , Chen Luwei , Lin Jianyi , Zeng Hua Chun 
Published: March 2012

AbstractWe have developed a low‐cost reaction protocol to synthesize mesoporous Nb2O5‐based solid acid catalysts with external shape control. In the synthesis, monodisperse glycolated niobium oxide spheres (GNOS) were prepared by means of a simple antisolvent precipitation approach and subsequently converted to mesoporous niobium oxide spheres (MNOS) with a large surface area of 312 m2 g−1 by means of the hydrothermal treatment. The antisolvent acetone used to obtain GNOS was recovered through distillation at high purity. The obtained mesoporous MNOS were functionalized further with sulfate anions at different temperatures or incorporated with tungstophosphoric acid to obtain recyclable solid acid catalysts. These MNOS‐based catalysts showed excellent performance in a wide range of acid‐catalyzed reactions, such as Friedel–Crafts alkylation, esterification, and hydrolysis of acetates. As they are monodisperse spheres with diameters in the submicrometer range, the catalysts can be easily separated and reused.
Mechanism of the Transition‐Metal‐Catalyzed Hydroarylation of Bromo‐Alkynes Revisited: Hydrogen versus Bromine Migration
Authors: Huang Genping , Cheng Bing , Xu Liang , Li Yahong , Xia Yuanzhi 
Published: March 2012

AbstractA comprehensive mechanistic study of the InCl3‐, AuCl‐, and PtCl2‐catalyzed cycloisomerization of the 2‐(haloethynyl)biphenyl derivatives of Fürstner et al. was carried out by DFT/M06 calculations to uncover the catalyst‐dependent selectivity of the reactions. The results revealed that the 6‐endo‐dig cyclization is the most favorable pathway in both InCl3‐ and AuCl‐catalyzed reactions. When AuCl is used, the 9‐bromophenanthrene product could be formed by consecutive 1,2‐H/1,2‐Br migrations from the Wheland‐type intermediate of the 6‐endo‐dig cyclization. However, in the InCl3‐catalyzed reactions, the chloride‐assisted intermolecular H‐migrations between two Wheland‐type intermediates are more favorable. These Cl‐assisted H‐migrations would eventually lead to 10‐bromophenanthrene through proto‐demetalation of the aryl indium intermediate with HCl. The cause of the poor selectivity of the PtCl2 catalyst in the experiments by the Fürstner group was predicted. It was found that both the PtCl2‐catalyzed alkyne–vinylidene rearrangement and the 5‐exo‐dig cyclization pathways have very close activation energies. Further calculations found the former pathway would lead eventually to both 9‐ and 10‐bromophenanthrene products, as a result of the Cl‐assisted H‐migrations after the cyclization of the Pt–vinylidene intermediate. Alternatively, the intermediate from the 5‐exo‐dig cyclization would be transformed into a relatively stable Pt–carbene intermediate irreversibly, which could give rise to the 9‐alkylidene fluorene product through a 1,2‐H shift with a 28.1 kcal mol−1 activation barrier. These findings shed new light on the complex product mixtures of the PtCl2‐catalyzed reaction.
Ellipsoidal TiO2 Hierarchitectures with Enhanced Photovoltaic Performance
Authors: Peng Wenqin , Yanagida Masatoshi , Chen Han , Han Liyuan 
Published: March 2012

AbstractHierarchical TiO2 ellipsoids 250–500 nm in size have been synthesized on a large scale by a template‐free hydrothermal route. The submicrometer‐sized hierarchitectures are assembled from highly crystallized anatase nanorods about 17 nm in diameter with macroporous cavities on the outer shells. Based on the time‐dependent morphological evolution under hydrothermal conditions, an oriented attachment process is proposed to explain formation of the hierarchical structures. Such hierarchical TiO2 not only adsorbs large amounts of dye molecules due to high surface area, but also shows good light scattering caused by the submicrometer size. The TiO2 hierarchitectures were deposited on top of a transparent TiO2 nanocrystalline main layer to construct a double‐layered photoanode for dye‐sensitized solar cell (DSC) application, exhibiting enhanced light harvesting and power‐conversion efficiency compared to a commercial TiO2‐based electrode.
Metamagnetism and Single‐Chain Magnetic Behavior in a Homospin One‐Dimensional Iron(II) Coordination Polymer
Authors: Boeckmann Jan , Wriedt Mario , Näther Christian 
Published: March 2012

AbstractReaction of FeCl2⋅4 H2O with KNCSe and pyridine in ethanol leads to the formation of the discrete complex [Fe(NCSe)2(pyridine)4] (1) in which the FeII cations are coordinated by two N‐terminal‐bonded selenocyanato anions and four pyridine co‐ligands. Thermal treatment of compound 1 enforces the removal of half of the co‐ligands leading to the formation of a ligand‐deficient (lacking on neutral co‐ligands) intermediate of composition [Fe(NCSe)2(pyridine)2]n (2) to which we have found no access in the liquid phase. Compound 2 is obtained only as a microcrystalline powder, but it is isotypic to [Cd(NCSe)2(pyridine)2]n and therefore, its structure was determined by Rietveld refinement. In its crystal structure the metal cations are coordinated by two pyridine ligands and four selenocyanato anions and are linked into chains by μ‐1,3 bridging anionic ligands. Magnetic measurements on compound 1 show only paramagnetic behavior, whereas for compound 2 an unexpected magnetic behavior is found, which to the best of our knowledge was never observed before for a iron(II) homospin compound. In this compound metamagnetism and single‐chain magnetic behavior coexist. The metamagnetic transition between the antiferromagnetically ordered phase and a field‐induced ferromagnetic phase of the high‐spin iron(II) spin carriers is observed at a transition field HC of 1300 Oe and the single‐chain magnetic behavior is characterized by a blocking temperature TB, estimated to be about 5 K.
A Combined Solid‐State NMR and X‐ray Crystallography Study of the Bromide Ion Environments in Triphenylphosphonium Bromides
Authors: Burgess Kevin M. N. , Korobkov Ilia , Bryce David L. 
Published: March 2012

AbstractMultinuclear (31P and 79/81Br), multifield (9.4, 11.75, and 21.1 T) solid‐state nuclear magnetic resonance experiments are performed for seven phosphonium bromides bearing the triphenylphosphonium cation, a molecular scaffold found in many applications in chemistry. This is undertaken to fully characterise their bromine electric field gradient (EFG) tensors, as well as the chemical shift (CS) tensors of both the halogen and the phosphorus nuclei, providing a rare and novel insight into the local electronic environments surrounding them. New crystal structures, obtained from single‐crystal X‐ray diffraction, are reported for six compounds to aid in the interpretation of the NMR data. Among them is a new structure of BrPPh4, because the previously reported one was inconsistent with our magnetic resonance data, thereby demonstrating how NMR data of non‐standard nuclei can correct or improve X‐ray diffraction data. Our results indicate that, despite sizable quadrupolar interactions, 79/81Br magnetic resonance spectroscopy is a powerful characterisation tool that allows for the differentiation between chemically similar bromine sites, as shown through the range in the characteristic NMR parameters. 35/37Cl solid‐state NMR data, obtained for an analogous phosphonium chloride sample, provide insight into the relationship between unit cell volume, nuclear quadrupolar coupling constants, and Sternheimer antishielding factors. The experimental findings are complemented by gauge‐including projector‐augmented wave (GIPAW) DFT calculations, which substantiate our experimentally determined strong dependence of the largest component of the bromine CS tensor, δ11, on the shortest BrP distance in the crystal structure, a finding that has possible application in the field of NMR crystallography. This trend is explained in terms of Ramsey’s theory on paramagnetic shielding. Overall, this work demonstrates how careful NMR studies of underexploited exotic nuclides, such as 79/81Br, can afford insights into structure and bonding environments in the solid state.
Correspondence of RuIIIRuII and RuIVRuIII Mixed Valent States in a Small Dinuclear Complex
Authors: Agarwala Hemlata , Scherer Thomas Michael , Maji Somnath , Mondal Tapan Kumar , Mobin Shaikh M. , Fiedler Jan , Urbanos Francisco A. , Jiménez‐Aparicio Reyes , Kaim Wolfgang , Lahiri Goutam Kumar 
Published: March 2012

AbstractThe diruthenium(III) compound [(μ‐oxa){Ru(acac)2}2] [1, oxa2−=oxamidato(2−), acac−=2,4‐pentanedionato] exhibits an S=1 ground state with antiferromagnetic spin‐spin coupling (J=−40 cm−1). The molecular structure in the crystal of 1⋅2 C7H8 revealed an intramolecular metal–metal distance of 5.433 Å and a notable asymmetry within the bridging ligand. Cyclic voltammetry and spectroelectrochemistry (EPR, UV/Vis/NIR) of the two‐step reduction and of the two‐step oxidation (irreversible second step) produced monocation and monoanion intermediates (Kc=105.9) with broad NIR absorption bands (ε ca. 2000 M−1 cm−1) and maxima at 1800 (1−) and 1500 nm (1+). TD‐DFT calculations support a RuIIIRuII formulation for 1− with a doublet ground state. The 1+ ion (RuIVRuIII) was calculated with an S=3/2 ground state and the doublet state higher in energy (ΔE=694.6 cm−1). The Mulliken spin density calculations showed little participation of the ligand bridge in the spin accommodation for all paramagnetic species [(μ‐oxa){Ru(acac)2}2]n, n=+1, 0, −1, and, accordingly, the NIR absorptions were identified as metal‐to‐metal (intervalence) charge transfers. Whereas only one such NIR band was observed for the RuIIIRuII (4d5/4d6) system 1−, the RuIVRuIII (4d4/4d5) form 1+ exhibited extended absorbance over the UV/Vis/NIR range.
Electrochemically Active Cross‐Linking Reaction for Fluorescent Labeling of Aliphatic Alkenes
Authors: Kim Shokaku , Hirose Kumi , Uematsu Jumpei , Mikami Yuzuru , Chiba Kazuhiro 
Published: March 2012

AbstractAlthough cross‐linking reactions serve as a valuable tool for the integration of two or more functionalities or properties, the application of electrochemical synthesis to cross‐linking reactions is restricted due to the difficulty of mass transfer. Thus, the primary purpose of this research is to explore electrochemical cross‐linking systems to construct a fluorescent probe, triggered by the formation of a covalent linkage. The second purpose is to apply the probe to insoluble targets. Towards these goals, a combination of electrochemically active phenol derivatives and aliphatic alkenes were employed to form polycyclic compounds. Several of the dihydrobenzofuran derivatives formed through [3+2] cyclization reactions exhibited fluorescence. Furthermore, this approach allowed the effective modification of alkene‐modified silica gel with electrochemically active species, which enables the construction of fluorescent probes that are triggered by CC bond formation.
CCS Separation Techniques – Review on Existing Technologies and Developments
Authors: Scherer Viktor , Stolten Detlef , Franz Johannes , Riensche Ernst 
Published: March 2012

AbstractDer folgende Beitrag fasst den Stand der Technik im Bereich der CO2‐Abscheidetechniken für kohlegefeuerte Kraftwerke zusammen und gibt einen Ausblick auf neuere Entwicklungen. Neben den bekannten Verfahren werden auch die Vor‐ und Nachteile membranbasierter Abscheidetechniken diskutiert sowie Chemical und Carbonate Looping, in denen ein Sauerstoff‐ oder CO2‐Trägermaterial im Kreislauf geführt wird, vorgestellt. Bei Verfahren, die auf heutigem Stand der Technik beruhen, ist mit Wirkungsgradverlusten in der Größenordnung von 10 %‐Punkten zu rechnen, wobei die Verdichtung auf Pipelinedruck schon eingerechnet ist. Neuere Entwicklungen lassen künftig Wirkungsgradverluste in der Größenordnung von 5 bis 10 %‐Punkten als realistisch erscheinen.
Agnes Pockels (1862 – 1935)
Authors: Mischnick Petra 
Published: March 2012

AbstractAgnes Pockels (1862 – 1935) gehörte zu der Generation von Frauen in Deutschland, denen höhere Schulbildung und ein Universitätsstudium noch verwehrt blieb. Zu ihrem 150. Geburtstag schauen wir mit großem Respekt auf ihr autodidaktisch und neben häuslichen Pflichten geschaffenes wissenschaftliches Werk, das grundlegende Beiträge zur Erforschung der Oberflächeneigenschaften von Wasser lieferte. Nach ihr ist das SchülerInnen‐Labor der TU Braunschweig benannt, das seit 2002 Mädchen wie Jungen die Möglichkeit bietet, die Naturwissenschaften experimentierend für sich zu entdecken.
Interference with kinesin‐based anterograde neurofilament axonal transport increases neurofilament‐neurofilament bundling
Authors: Sunil Neethu , Lee Sangmook , Shea Thomas B. 
Published: March 2012

AbstractNeurofilaments (NFs) associate with each other and with other cytoskeletal elements to form a lattice that supports the mature axon. Phosphorylation contributes to formation of this stationary population of NFs by fostering cation‐dependent interactions among NF sidearms. Association of NFs with the stationary phase indirectly competes with NF axonal transport by withdrawing NFs from kinesin‐dependent motility along microtubules. We therefore hypothesized that inhibition of anterograde NF transport may increase incorporation into the stationary phase. To test this hypothesis, we treated differentiated NB2a/d1 cells expressing GFP‐tagged NF subunits with monastrol, a specific inhibitor of kinesin‐5. Monastrol significantly inhibited anterograde axonal transport of NF‐H but not NF‐M, and increased the incorporation of newly‐transported NF subunits into axonal NF bundles. These findings support the notion that NF transport and bundling exert opposing forces on axonal NF dynamics, and that inhibition of anterograde transport of NFs can increase their incorporation into the stationary phase. © 2012 Wiley Periodicals, Inc