bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of trans,trans‐muconic acid in workers' urine through ultra‐performance liquid chromatography coupled to tandem mass spectrometry
Authors: Gagné Sébastien
Published: December 2012

A novel method for the biological monitoring of benzene‐exposed workers has been developed through ultra‐performance liquid chromatography coupled to tandem mass spectrometry. The method uses trans,trans‐muconic acid in urine as the benzene‐exposure biomarker. The method was developed using a triple quadrupole mass spectrometer with enough sensitivity to facilitate diluting and injecting the urine samples directly, rather than performing a solid‐phase extraction procedure as is common in the available protocols. Moreover, compared with a conventional high‐pressure liquid chromatography system, the separation power provided by the ultra‐performance liquid chromatography system allows a 10‐fold reduction in run time. The method was adjusted to a dynamic range of between 198.9 and 4916.7 µg/L to cover the biological exposure index of trans,trans‐muconic acid in urine. Also, the method demonstrated intra‐day and inter‐day precision at 98%, and accuracy within an acceptable range of 101 ± 8%. The method has been used to quantify various types of urine samples, such as workers' urine and inter‐laboratory proficiency tests. Depending on the sample, the quantified levels ranged from less than the limit of quantitation to 3836.7 µg/L. No levels exceeding the calibration range were detected in the urine of workers, and the reported concentrations in urine for the proficiency tests were, as expected, based on known values. Moreover, the new method using sample dilution and faster chromatographic run was more effective, facilitating fast communication of results, as needed, to decision‐makers. Copyright © 2012 John Wiley & Sons, Ltd.
Copper‐Free Asymmetric Allylic Alkylation with a Grignard Reagent: Design of the Ligand and Mechanistic Studies
Authors: Grassi David , Dolka Chrysanthi , Jackowski Olivier , Alexakis Alexandre
Published: December 2012

The Cu‐free asymmetric allylic alkylation, catalysed by NHC, with Grignard reagents is reported on allyl bromide derivatives with good results. The enantioselectivity was quite homogeneous (around 85 % ee) on large and various substrates, regardless of the nature of the Grignard reagent. The formation of stereogenic quaternary centres was highly regioselective for both aliphatic and aromatic derivatives with good enantiomeric excess (up to 92 % ee). The methodology developed was found to be complementary with the Cu‐catalysed version. Several new NHCs were tested with improved efficiency. In addition, mechanistic studies, using NMR spectroscopy, led to the discovery of the catalytically active species.
Innovative Artificial Agro‐Ecosystems Enhance Soil Carbon Sequestration in Coastal Zones of Southeast China
Authors: Zhao Gengmao , Sun Xing , Ling Liu , Liu Zhaopu
Published: December 2012

Tidal flats, which are important reserved land resources, have a vital role in climate change. To evaluate the contribution of coastal saline soils to carbon sequestration, field tests were performed over a 3 year period at the Dafeng Wanggang Experimental Station in Jiangsu Province, China. Six artificial agro‐ecosystems, including wasteland (WL), freshwater fish culture (FC), Sesbania culture (SC), barley culture (BC), mixed culture of fish and Sesbania (MCFS) and mixed culture of fish and barley (MCFB), were established according to developmental processes of coastal saline soils. At the initial stage of tidal flat reclamation, the soil organic carbon (SOC) increased by 59.4 t ha−1 in the FC system during 3 years, which was much higher than that of the WL system (40.7 t ha−1). When the tidal flats evolved into high saline soils, the MCFS system sequestered SOC more effectively than the FC or SC systems with increases of 53.1, 16.9 and 8.3 t ha−1, respectively. Subsequently, in the low saline soils, the maximum soil carbon sequestration was obtained in the MCFB system (35.8 t ha−1) followed by the BC (17.5 t ha−1) and FC (13.5 t ha−1) systems. Therefore, proper development of tidal flats to farmland and the subsequent establishment of optimised artificial agro‐ecosystems make an important contribution to carbon sequestration and climate changes in coastal areas.
Exploring the Polyamine Regulatory Site of the NMDA Receptor: a Parallel Synthesis Approach
Authors: Berger Michael L. , Pöhler Thomas , Schadt Oliver , Stanger Maximilian , Rebernik Patrick , Scholze Petra , Noe Christian R.
Published: December 2012

The elongated structures of polyamine inverse agonists such as 1,12‐diaminododecane (N12N) and 5‐(4‐aminobutyl)‐2‐thiopheneoctanamine (N4T8N) lend themselves to a combinatorial chemistry approach to explore a potential polyamine pharmacophore at the NMDA receptor. Herein we describe more than 100 new analogues of N4T8N obtained by breaking up the long octanamine arm into a dipeptide chain of equivalent length. Solid‐phase parallel synthesis based on cross‐linked polystyrene and a Wang anchor allowed the low‐scale preparation of four small libraries based on the combination of two amino acid residues (out of Gly, Leu, Phe, Lys, phenylglycine, Tyr, Trp, His, and Arg). The obtained compounds were tested as modulators of [3H]MK‐801 binding to rat brain membranes and of NMDA‐induced currents in cultured rat hippocampal neurons. Compounds with two aromatic residues acted as binding inhibitors (inverse agonists). Compounds with two Lys residues acted as binding stimulators (agonists) and had stimulatory and inhibitory effects on NMDA‐induced currents, depending on the holding potential. High sensitivity of binding inhibition to spermine was conferred by a Tyr residue, whereas a His residue favored high potency at acidic pH.
Visible and near infrared fluorescence spectral flow cytometry
Authors: Nolan John P. , Condello Danilo , Duggan Erika , Naivar Mark , Novo David
Published: December 2012

There is a long standing interest in measuring complete emission spectra from individual cells in flow cytometry. We have developed flow cytometry instruments and analysis approaches to enable this to be done routinely and robustly. Our spectral flow cytometers use a holographic grating to disperse light from single cells onto a CCD for high speed, wavelength‐resolved detection. Customized software allows the single cell spectral data to be displayed and analyzed to produce new spectra‐derived parameters. We show that familiar reference and calibration beads can be employed to quantitatively assess instrument performance. We use microspheres stained with six different quantum dots to compare a virtual bandpass filter approach with classic least squares (CLS) spectral unmixing, and then use antibody capture beads and CLS unmixing to demonstrate immunophenotyping of peripheral blood mononuclear cells using spectral flow cytometry. Finally, we characterize and evaluate several near infrared (NIR) emitting fluorophores for use in spectral flow cytometry. Spectral flow cytometry offers a number of attractive features for single cell analysis, including a simplified optical path, high spectral resolution, and streamlined approaches to quantitative multiparameter measurements. The availability of robust instrumentation, software, and analysis approaches will facilitate the development of spectral flow cytometry applications. © 2012 International Society for Advancement of Cytometry
Genetic diversity of North American captive‐born gorillas (Gorilla gorilla gorilla)
Authors: Simons Noah D. , Wagner Ronald S. , Lorenz Joseph G.
Published: December 2012

Western lowland gorillas (Gorilla gorilla gorilla) are designated as critically endangered and wild populations are dramatically declining as a result of habitat destruction, fragmentation, diseases (e.g., Ebola) and the illegal bushmeat trade. As wild populations continue to decline, the genetic management of the North American captive western lowland gorilla population will be an important component of the long‐term conservation of the species. We genotyped 26 individuals from the North American captive gorilla collection at 11 autosomal microsatellite loci in order to compare levels of genetic diversity to wild populations, investigate genetic signatures of a population bottleneck and identify the genetic structure of the captive‐born population. Captive gorillas had significantly higher levels of allelic diversity (t7 = 4.49, P = 0.002) and heterozygosity (t7 = 4.15, P = 0.004) than comparative wild populations, yet the population has lost significant allelic diversity while in captivity when compared to founders (t7 = 2.44, P = 0.04). Analyses suggested no genetic evidence for a population bottleneck of the captive population. Genetic structure results supported the management of North American captive gorillas as a single population. Our results highlight the utility of genetic management approaches for endangered nonhuman primate species.
Four Members of the Sandwich‐Type Polytungstophosphate Family Based on Pentalacunary [HPW7O28]8– Building Blocks
Authors: Zhang Dongdi , Zhang Yanhui , Zhao Juan , Ma Pengtao , Wang Jingping , Niu Jingyang
Published: December 2012

Four dimeric mononuclear sandwich‐type tungstophosphate clusters of Na12H[FeIII(HPW7O28)2]·44H2O (1) and Na14[M(HPW7O28)2]·44H2O {M = CoII (2), CdII (3), MnII (4)} were successfully synthesized by reaction of Na2WO4·2H2O, H3PO4, and CH3COOH with FeCl3·6H2O, Co(CH3COO)2·4H2O, CdSO4·8H2O, and Mn(CH3COO)2·4H2O, respectively. Single‐crystal X‐ray diffraction analysis revealed that 1–4 are essentially isomorphous and crystallize in the triclinic space group P$\bar {1}$. Complexes 1–4 consist of two [HPW7O28]8– units incorporating a single FeIII, CoII, CdII, and MnII ion, respectively. Furthermore, the electrocatalytic behaviors of 1–4 in the reduction of nitrite were investigated.
Production of nitrogen‐based platform chemical: cyanophycin biosynthesis using recombinant Escherichia coli and renewable media substitutes
Authors: Zhang Yixing , Kumar Amit , Vadlani Praveen V. , Narayanan Sanjeev
Published: December 2012

Background

Cyanophycin (CGP) is a sustainable polymer that can be converted to a derivative with reduced arginine content, or to completely biodegradable poly‐aspartic acid, which can substitute for non‐biodegradable polyacrylates. In nature, it is produced by most cyanobacteria; however, these microbes are not suitable for large‐scale production due to slow growth and low polymer content.

Results

Cyanophycin synthetase gene (cphA) from Anabaena variabilis ATCC 29413 was PCR amplified and cloned into Escherichia coli. Different renewable media components, such as soybean meal, potato wastes and corn‐derived zein hydrolysate, were evaluated for their feasibility for CGP production at shake flask level. The optimized conditions were then tested in a 7 L bioreactor; a maximum cell weight of 10.2 g L‐1 was obtained. CGP comprised 23 g g‐1 of cell dry matter (CDM) with molecular weight between 21.5 and 31 kDa and was composed of aspartic acid, arginine and lysine in the ratio of 1.05:1:0.2 (mass basis).

Conclusion

The efficient use of renewable biomass for cyanophycin production could achieve competitive price, and in return, promote the use of this platform chemical to produce innovative polymers and materials.© 2012 Society of Chemical Industry
Evaluation of Ba‐promoted Mo carbide catalyst for Fischer–Tropsch synthesis
Authors: Vo Dai‐Viet N. , Arcotumapathy Viswanathan , Abdullah Bawadi , Adesina Adesoji A.
Published: December 2012

Background

Traditional FT catalysts such as Co and Fe still suffer from carbon‐induced deactivation even with alkali promotion. The objective of this study was to examine the effect of Ba addition to carbon‐tolerant Mo carbide since it has Pt‐like characteristics and is cheaper than noble metals as an FT catalyst.

Results

The presence of Ba increased the Mo carbide production rate and reduced the activation energy for its formation. The promoted catalyst exhibited higher specific basic site strength and CO2 uptake for strong basic site than that of the undoped catalyst. Both catalysts exhibited optimal reaction rate at a H2 mole fraction of 0.75 while CO consumption rate, total olefin‐to‐paraffin ratio, methane suppression as well as C5+ selectivity were improved with Ba addition. The non‐standard Anderson–Schulz–Flory (ASF) product distribution observed for the Ba‐doped catalyst may be due to the appearance of an additional polymerization site on the catalyst surface located in the BaMoO4 phase. Chain growth factor was enhanced by up to 93% from 0.43 to 0.83 with the Ba‐doped catalyst.

Conclusions

Ba promoter increased chain growth probability by about 93%. The deviation of product distribution from standard ASF plots with 2 chain growth factors for the 3wt%Ba‐10%MoC1‐x/Al2O3 catalyst was probably due to the presence of different active sites for chain initiation. The result is unprecedented and represents excellent opportunity for industrial exploitation of a new and relatively cheap carbon‐resistant catalyst.© 2012 Society of Chemical Industry
Tetracycline degradation and mineralization by the coupling of an electro‐Fenton pretreatment and a biological process
Authors: Ferrag‐Siagh Fatiha , Fourcade Florence , Soutrel Isabelle , Aït‐Amar Hamid , Djelal Hayet , Amrane Abdeltif
Published: December 2012

BACKGROUND

Studies on the degradation and mineralization of tetracycline by means of the electro‐Fenton process are lacking in the available literature. Its relevance as a pre‐treatment prior to a biological process for the removal of tetracycline was therefore examined.

RESULTS

Degradation followed pseudo‐first‐order kinetics and the optimal operating conditions were: 0.1 mmol L‐1 catalyst (Fe2+) concentration, 300 mA applied current intensity and 25 mg L‐1 tetracycline, leading to total degradation within only 5 min and a mineralization yield of 89 % after 6 h electrolysis. Biodegradability tests were realized with 100 mg L‐1 tetracycline; BOD5/COD ratio increased from 0.02 to 0.56 after 6 h electrolysis, showing the relevance of the electro‐Fenton pre‐treatment. However, to keep a significant residual organic content, 2 to 4 h electrolysis time may be more relevant, leading to BOD5/COD ratio and mineralization yields of 0.33–0.44 and 46–72%, respectively.

CONCLUSION

Activated sludge cultures of pretreated and non‐pretreated tetracycline solutions were carried out for 3 weeks. The overall TOC removal increased from 28% for the non‐pretreated tetracycline to 68 and 86% after 2 and 4 h electrolysis, confirming the efficiency of the proposed combined process. © 2012 Society of Chemical Industry
Years‐identification mathematical model of paeonia lactiflora pall. based on the allometric‐scaling
Authors: Cheng Chunsong , Peng Daiyin , Huang Luqi , Ma Xiaohui
Published: December 2012

The fixed number years‐identification of Chinese material medicinal was a difficulty in the process of the traditional Chinese pharmacology, the phenomenon was found in our study of telomerase that the speed of the vascular cambium outside expanding growth fluctuated in a definite value. Based on it, we put forward a hypothesis that the radial length of the vascular cambium to expand (Δb)and the radius of cross section (Δr) are constant in every activity cycle if the external environment factors unchanged every year. Therefore, We defined that the proportion (k) of Δr and Δb is constant (Δr/Δb = k). Then, each of Δb and Δr fluctuating in a fixed value in every year, because of the different rainfall, temperature, and sunniness every year. The hypothesis was proved correct within the domain of definition range, through the extrapolation of mathematical method. Hence, the telomerase experimental results just become effective evidence on mechanism. The conclusion we obtained include the following three: the telomerase experimental show that the activity gradually decreased in the Paeonia overall taproot, while, the it does not seem significantly change in the parts of the cambium cells with increasing age; Microscopy studies and mathematical models exploration gave us an identification method which can determine the growth years of Chinese medicinal materials (Refers to a kind of herbs exclusive which contains taproot), and, for example, we can use the mathematical model y = 0.02x−0.5
$ \left(P = {0.08 \over {k^2}{n}\Delta {b}}-{0.0016 \over \Delta {b }^2{ n}^2{ k}^2}\right) $
to identify the years of the Paeonia lactiflora Pall; the power function of allometric‐scaling explored at microscopic cellular‐level firstly. Ginseng, for example, more definitive proved a mathematical relationship of the allometric scaling in the taproot of plants. Microsc. Res. Tech., 2013. © 2012 Wiley Periodicals, Inc.
Probing AGXT2 enzyme activity in mouse tissue by applying stable isotope‐labeled asymmetric dimethyl arginine as substrate
Authors: Martens‐Lobenhoffer Jens , Rodionov Roman N. , Bode‐Böger Stefanie M.
Published: December 2012

Asymmetric dimethylarginine (ADMA) is a metabolite of the amino acid l‐arginine. It competitively inhibits the enzymatic production of the cell‐signaling substance nitric oxide. Therefore, increased levels of ADMA are associated with a range of cardiovascular and other diseases. ADMA is biologically eliminated by direct renal excretion and hydrolysis by the enzyme DDAH. Recently, a further elimination pathway via the transamination by the enzyme AGXT2 to α‐keto‐δ‐(NG,NG‐dimethylguanidino)valeric acid (DMGV) has come into the focus of biological research. In this work, we describe an assay for the AGXT2 activity in mouse liver and kidney tissue. It is based on the transformation of isotope‐labeled ADMA‐d6 to DMGV‐d6. The quantification of the DMGV‐d6 produced by this reaction in tissue homogenate samples was accomplished by chromatographic separation on a porous graphitic carbon column and tandem mass spectrometric detection. DMGV‐d6 with the deuterium labels in different molecular positions was used as internal standard. The overall production rates of DMGV‐d6 in mice were 195.37 pmol/min/mg total protein in liver and 85.21 pmol/min/mg total protein in kidney tissue, with coefficients of variation of 6.31% and 11.25%, respectively. This method can be applied as a tool for the characterization of the ADMA elimination by the AGXT2 pathway. Copyright © 2012 John Wiley & Sons, Ltd.
10Be ages of late Pleistocene deglaciation and Neoglaciation in the north‐central Brooks Range, Arctic Alaska
Authors: Badding Michael E. , Briner Jason P. , Kaufman Darrell S.
Published: December 2012

We present a chronology of late Pleistocene deglaciation and Neoglaciation for two valleys in the north‐central Brooks Range, Alaska, using cosmogenic 10Be exposure dating. The two valleys show evidence of ice retreat from the northern range front before ∼16–15 ka, and into individual cirques by ∼14 ka. There is no evidence for a standstill or re‐advance during the Lateglacial period, indicating that a glacier advance during the Younger Dryas, if any, was less extensive than during the Neoglaciation. The maximum glacier expansion during the Neoglacial is delimited by moraines in two cirques separated by about 200 km and dated to 4.6 ± 0.5 and 2.7 ± 0.2 cal ka BP. Both moraine ages agree with previously published lichen‐inferred ages, and confirm that glaciers in the Brooks Range experienced multiple advances of similar magnitude throughout the late Holocene. The similar extent of glaciers during the middle Holocene and the Little Ice Age may imply that the effect of decreasing summer insolation was surpassed by increasing aridity to limit glacier growth as Neoglaciation progressed. Copyright © 2012 John Wiley & Sons, Ltd.
Ultrasonic Breaking of Fibers and Microparticles into Mesoporous Particles with High Loading of Magnetic Nanoparticles
Authors: Hyun Dong Choon , Jo Eunmin , Park Choo Jin , Lim Min‐Cheol , Paik Hyun‐Jong , Cho Eun Chul , Kim Young‐Rok , Jeong Unyong
Published: December 2012

Herein, a facile method for the large‐scale production of mesoporous polymer/nanoparticle (NP) composites, with high‐loading‐efficiency of nanoparticles, is presented. The composite fibers and microparticles composed of polystyrene (PS), poly(ethylene oxide) (PEO), and Fe2O3 NPs were obtained by electrojetting. After selectively dissolving the PEO phase, simple ultrasonication broke the porous fibers and the microparticles into numerous small mesoporous composite particles. For the breaking of the fibers and microparticles, the use of low‐molecular‐weight polymer was critical. As an example demonstration, we produced mesoporous PS particles with a large amount of magnetic NPs.

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Photo‐Degradable, Protein–Polyelectrolyte Complex‐Coated, Mesoporous Silica Nanoparticles for Controlled Co‐Release of Protein and Model Drugs
Authors: Wan Xuejuan , Liu Tao , Hu Jinming , Liu Shiyong
Published: December 2012

The fabrication of photo‐degradable, protein–polyelectrolyte complex (PPC)‐coated, mesoporous silica nanoparticles (MSNs) and their controlled co‐release of protein and model drugs is reported. Random copolymers composed of oligo(ethylene glycol) monomethyl ether methacrylate (OEGMA), and a photolabile o‐nitrobenzyl‐containing monomer, 5‐(2′‐(dimethylamino)ethoxy)‐2‐nitrobenzyl methacrylate (DENBMA), are first anchored onto the MSNs and then quaternary aminated, to obtain positively charged P(OEGMA‐co‐TENBMA) which exhibits photo‐induced charge conversion characteristics. PPCs consisting of P(OEGMA‐co‐TENBMA) and the protein bovine serum albumin (BSA) are utilized as capping agents for the nanopores of the MSNs. Upon UV irradiation, charge conversion of P(OEGMA‐co‐TENBMA) can lead to the disruption of PPCs on MSNs and co‐release of BSA and rhodamine B by electrostatic repulsion.
Effect of surface modification of aluminum nitride on electrical and thermal characterizations of thermosetting polymeric nanocomposites
Authors: Choudhury Mousam , Mohanty Smita , Nayak Sanjay K.
Published: December 2012

Thermally conductive composites and nanocomposites composed of epoxy resin as base matrix and aluminum nitride (AlN) as micro and nanofiller have been studied at variable temperatures and loading of AlN. To improve the dispersion of the filler within the polymer matrix, AlN was surface modified with silane‐coupling agent. Thermogravimetric analysis confirmed the interfacial bonding of epoxy‐ and silane‐modified AlN. The dielectric properties of epoxy/AlN composites and nanocomposites have been studied at variable percentage of filler. Test result indicated an increase of thermal conductivity of the composites at 20 wt% of AlN. Also, silane‐treated composites exhibited improved electrical conductivity properties, whereas the electrical insulation property decreased in terms of dielectric strength and resistivity. POLYM. COMPOS., 2013. © 2012 Society of Plastics Engineers
First principles electronic structure of coincidence site epitaxial Ag/Si(111) interface
Authors: Abdul Wasey A. H. M. , Batabyal R. , Mahato J. C. , Dev B. N. , Kawazoe Y. , Das G. P.
Published: December 2012

Ag/Si(111) heterojunction having ∼25% lattice mismatch can be formed by placing four surface unit cells of Ag(111) on three surface unit cells of Si(111), thereby reducing the effective strain in the Ag film to ∼0.3% in this coincidence site epitaxial growth. We have carried out first‐principles investigation of such Ag/Si(111) interface to establish the interplay between the structural and electronic properties. While the Ag overlayer affects the reconstruction of the Si(111) surface, we find that the geometrical relaxation of the Ag atoms is influenced by the sub‐surface Si‐layer and the concomitant lattice mismatch. The electronic density of states show some oscillations near the Fermi energy, which have been compared with the scanning tunnelling spectroscopic (STS) experimental data. The signature of metal‐induced gap states (MIGS) for this metal–semiconductor heterojunction has been established from the evolution of localized gap states in the layer projected density of states. Our DFT estimated work function values for Ag(100), (110) and (111) have an excellent agreement with the available experimental results. Also, the p‐type Schottky barrier height (SBH) of this rectifying Ag/Si contact has been calculated from the Kohn–Sham estimates of EF − Ev modified by the interface induced dipole.
Magnetotransport and induced superconductivity in Bi based three‐dimensional topological insulators
Authors: Veldhorst M. , Snelder M. , Hoek M. , Molenaar C. G. , Leusink D. P. , Golubov A. A. , Hilgenkamp H. , Brinkman A.
Published: December 2012

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The surface of a three‐dimensional (3D) topological insulator is conducting and the topologically nontrivial nature of the surface states is observed in experiments. It is the aim of this paper to review and analyze experimental observations with respect to the magnetotransport in Bi‐based 3D topological insulators, as well as the superconducting transport properties of hybrid structures consisting of superconductors and these topological insulators. The helical spin‐momentum coupling of the surface state electrons becomes visible in quantum corrections to the conductivity and magnetoresistance oscil‐lations. An analysis will be provided of the reported magnetoresistance, also in the presence of bulk conductivity shunts. Special attention is given to the large and linear magnetoresistance. Superconductivity can be induced in topological superconductors by means of the proximity effect. The induced supercurrents, Josephson effects and current–phase relations will be reviewed. These materials hold great potential in the field of spintronics and the route towards Majorana devices. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A quad‐band W‐CDMA transceiver IC–direct conversion architecture with fractional frequency divider
Authors: Kamizuma Hiroshi , Akamine Yukinori , Yamawaki Taizo , Hikasa Kazuhiko
Published: December 2012

A quad‐band (0.8, 1.7, 2, and 1.4 GHz) wideband code division multiple access (W‐CDMA) transceiver, which uses a divide‐by‐2.5 frequency divider in local parts of a direct‐conversion architecture, has been developed. Using the fractional‐2.5 frequency divider reduces the fractional bandwidth of the voltage‐controlled oscillator and avoids injection locking of the local RF synthesizer perfectly. This transceiver achieved 3% error‐vector magnitude and—46 dB ACLR, which satisfy the margin given in standard specifications. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Optimal frequency tracking method for phase‐shift PWM inverter
Authors: Kifune Hiroyasu , Hatanaka Yoshihiro
Published: December 2012

This paper proposes a new resonant frequency tracking control method for full‐bridge‐type high‐frequency inverters. Whereas the ordinary phase‐locked loop (PLL) based frequency control method uses a current sensor and a voltage sensor, the proposed technique can achieve the same purpose with a single current sensor. In high‐frequency power supply systems using a PLL, it is impossible to perform power control with an inverter. Therefore, an active converter must be used for power control, and the system grows larger. On the other hand, high‐frequency inverters using the proposed control system simultaneously enable power control and achieve the same resonant frequency tracking as a PLL, and thus high‐frequency power supply systems become extremely simple. This paper explains in detail the principle underlying the control method, and presents an example of a circuit to realize it. The theory is backed up by using a prototype high‐frequency power supply system which actually employs the proposed control system, thereby demonstrating its practical utility in industry. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Effect of commercial grade endosulfan on growth and reproduction of the fighting fish Betta splendens
Authors: Balasubramani A. , Pandian T. J.
Published: December 2012

To study the effects of endosulfan on survival, growth and reproduction of the obligate air‐breathing male heterogametic fighting fish Betta splendens, posthatchlings of the fighting fish were discretely immersed for 3 h/day during the labile period on the 2nd, 5th, and 8th day posthatching (dph) at selected concentrations of commercial grade endosulfan ranging from 175 to 1400 ng/L. The immersions at 1,400 ng/L led to 21% mortality, among the 79% of surviving fry, 80% developed into females. The endosulfan reduced the air‐breathing frequency of 5‐ and 8‐day old hatchlings, and the reduction in the frequency persisted even after a depuration period of 172 days. In the ovary of the treated females, reduced number of vitellogenic oocytes with increased vacuolar cavities was observed. In the testis of the treated males, the reduced number of spermatogonia with increased vacuolar cavities was observed. The treated male induced the female to spawn a fewer eggs, which were subsequently incubated in his smaller bubble nest. The control females attained puberty on the 138th dph and spawned 120 eggs once in every 15 days, the females, which were previously treated at 1400 ng/L, postponed puberty to the 179th dph and spawned 70 eggs once in every 32 days. During the 240‐day experiment, endosulfan is found to reduce significantly the cumulative progeny production from 760 to 144, reducing significantly to 19% of the control. © 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 1054–1062, 2014.
Improving routing in networks of Unmanned Aerial Vehicles: Reactive‐Greedy‐Reactive
Authors: Li Yi , Shirani Rostam , St‐Hilaire Marc , Kunz Thomas
Published: December 2012

Because of their specific characteristics, Unmanned Aeronautical Ad‐hoc Networks (UAANETs) can be classified as a special kind of mobile ad hoc networks. Because of the high mobility of Unmanned Aerial Vehicles, designing a good routing protocol for UAANETs is challenging. Here, we present a new protocol called Reactive‐Greedy‐Reactive (RGR) as a promising routing protocol in high mobility and density‐variable scenarios. RGR combines features of reactive MANET routing protocols such as Ad‐hoc On‐demand Distance Vector with geographic routing protocols, exploiting the unique characteristics of UAANETs. In addition to combining reactive and geographic routing, the protocol has a number of features to further improve the overall performance. We present the rationale and design of the protocol, discuss the specific performance improvements in detail and provide extensive simulation results that demonstrate that RGR outperforms purely reactive or geographic routing protocols. The results also demonstrate the impact of the various protocol modifications. Copyright © 2012 John Wiley & Sons, Ltd.
P2Y receptors in dendritic cells: from inflammation to tolerance
Authors: Communi Didier , Robaye Bernard
Published: December 2012

Extracellular nucleotides released in the context of immune and inflammatory responses regulate all components of dendritic cell (DC) function: chemotaxis, antigen uptake, expression of costimulatory molecules, and cytokine secretion. Furthermore, mainly using gene expression profiling, we identified a large number of ATP target genes in human DCs that could play a role in tolerance and tumor development. We have now integrated these findings and related publications in a nonexhaustive review of the wide action of ATP on DCs. ATP, which was previously considered as a danger signal, is also a potent regulator of immunosuppressive and tolerogenic proteins such as thrombospondin‐1 and indoleamine 2′,3′‐dioxygenase. ATP induces a semimaturation state of DCs that can be associated with immune tolerance by regulating costimulatory molecules and cytokine/chemokine expression profiles. Immune tolerance could thus be initiated at the level of DCs. These actions are mediated by the P2Y11 receptor and P2Y11 agonists could thus be used to generate tolerogenic DCs and as useful tools for DC‐based immunotherapies. ATP released from tumor cells can have a tumorigenic action through the generation of semimature tolerogenic DCs and the secretion of angiogenic factors such as vascular endothelial growth factor (VEGF) and amphiregulin from DCs. Antagonists of ATP receptors expressed on DCs and antibodies blocking ATP target genes could have a therapeutic potential by acting as antitumor agents. WIREs Membr Transp Signal 2013, 2:37–42. doi: 10.1002/wmts.75

For further resources related to this article, please visit the WIREs website.
Ten‐year Comparison of All‐Cause Mortality after Endovascular or Open Repair of Abdominal Aortic Aneurysms: A Propensity Score Analysis
Authors: Lee Hong‐Gi , Clair Daniel G. , Ouriel Kenneth
Published: December 2012

Background

This study aimed to compare the long‐term survival after open (OS) or endovascular (EVAR) repair of abdominal aortic aneurysms (AAAs), exploring baseline factors that could affect long‐term outcome.

Methods

We identified 774 patients (501 EVAR, 273 OS, during 1996–2004) with data on perioperative risk factors including 37 variables assessed with a standardized patient response instrument. Propensity score was used to adjust for baseline differences between the two cohorts. Matched cohorts survival analysis and Cox multivariate regression were performed.

Results

Median follow‐up was 6.95 (interquartile range 4.46–9.27) years. EVAR patients were older [75.0 ± 7.7 (SD) vs. 71.3 ± 8.5 years, p < 0.001] and had a higher rate of previous myocardial infarction (39.3 vs. 25.3 %, p < 0.001), pulmonary disease (25.9 vs. 18.3 %, p = 0.020), and history of malignancy (5.0 vs. 1.8 %, p = 0.039). The 30‐day mortality was comparable (1.4 % EVAR, 1.5 % OS). Although the unadjusted survival rate was lower (median survival: 7.4 years EVAR, 8.8 OS, p = 0.011) and early (within 4 years) hazard was higher after EVAR (p = 0.003), no difference in survival was observed after propensity score‐matching (p = 0.688) or propensity score‐adjusted Cox regression (hazard ratio 1.01, 95 % confidence interval 0.82–1.25, p = 0.911, EVAR vs. OS). There was a trend toward higher hazard later in both groups. A multivariate Cox regression identified age, pulmonary disease, stroke, dialysis, oral anticoagulation, cardiac enlargement, and smoking history as variables associated with poor survival. Lipid‐lowering medication was found to be protective.

Conclusions

Over long‐term follow‐up, survivals after endovascular and open repair of AAA are similar. Baseline patient characteristics are correlated with survival, but whether attention to the modifiable risk factor can alter outcome remains to be defined.
Dentin hypersensitivity: pain mechanisms and aetiology of exposed cervical dentin
Authors: West N. X. , Lussi A. , Seong J. , Hellwig E.
Published: December 2012

Objectives

The paper’s aim is to review dentin hypersensitivity (DHS), discussing pain mechanisms and aetiology.

Materials and methods

Literature was reviewed using search engines with MESH terms, DH pain mechanisms and aetiology (including abrasion, erosion and periodontal disease).

Results

The many hypotheses proposed for DHS attest to our lack of knowledge in understanding neurophysiologic mechanisms, the most widely accepted being the hydrodynamic theory. Dentin tubules must be patent from the oral environment to the pulp. Dentin exposure, usually at the cervical margin, is due to a variety of processes involving gingival recession or loss of enamel, predisposing factors being periodontal disease and treatment, limited alveolar bone, thin biotype, erosion and abrasion.

Conclusions

The current pain mechanism of DHS is thought to be the hydrodynamic theory. The initiation and progression of DHS are influenced by characteristics of the teeth and periodontium as well as the oral environment and external influences. Risk factors are numerous often acting synergistically and always influenced by individual susceptibility.

Clinical relevance

Whilst the pain mechanism of DHS is not well understood, clinicians need to be mindful of the aetiology and risk factors in order to manage patients’ pain and expectations and prevent further dentin exposure with subsequent sensitivity.
Methods for Mediation Analysis with Missing Data
Authors: Zhang Zhiyong , Wang Lijuan
Published: December 2012

Despite wide applications of both mediation models and missing data techniques, formal discussion of mediation analysis with missing data is still rare. We introduce and compare four approaches to dealing with missing data in mediation analysis including listwise deletion, pairwise deletion, multiple imputation (MI), and a two-stage maximum likelihood (TS-ML) method. An R package bmem is developed to implement the four methods for mediation analysis with missing data in the structural equation modeling framework, and two real examples are used to illustrate the application of the four methods. The four methods are evaluated and compared under MCAR, MAR, and MNAR missing data mechanisms through simulation studies. Both MI and TS-ML perform well for MCAR and MAR data regardless of the inclusion of auxiliary variables and for AV-MNAR data with auxiliary variables. Although listwise deletion and pairwise deletion have low power and large parameter estimation bias in many studied conditions, they may provide useful information for exploring missing mechanisms.
Mother knows best? Inhibitory maternal gatekeeping, psychological control, and the mother–adolescent relationship
Authors: Holmes Erin Kramer , Dunn KayLee C. , Harper James , Dyer W. Justin , Day Randal D.
Published: December 2012

We used structural equation modeling to explore associations between inhibitory maternal gatekeeping attitudes, reports of inhibitory maternal gatekeeping behaviors, maternal psychological control, observed mother–adolescent warmth, and adolescent reports of maternal involvement. Our random stratified sample consisted of 315 mothers and their adolescents. Results revealed that inhibitory maternal gatekeeping attitudes were positively associated with reports of inhibitory gatekeeping behaviors. Psychological control fully mediated the relationship between inhibitory gatekeeping attitudes, reports of inhibitory gatekeeping behaviors, and adolescent reports of maternal involvement. Though gatekeeping attitudes and behaviors were not associated with observed mother–adolescent warmth, psychological control was negatively associated with observed mother–adolescent warmth. Thus, although prior research emphasized the negative effects of inhibitory gatekeeping on father–child relationships, the present research elucidates that in conjunction with psychological control, inhibitory gatekeeping negatively influences the mother–adolescent relationship. All findings are discussed in the context of family systems theory.
ORIENTATION IN THREE SPHERES: MEDIEVAL MEDITERRANEAN BOUNDARY CLAUSES IN LATIN, GREEK AND ARABIC
Authors: Metcalfe Alex
Published: December 2012

This paper investigates the development of land registry traditions in the medieval Mediterranean by examining a distinctive aspect of Latin, Greek and Arabic formularies used in boundary clauses. The paper makes particular reference to Islamic and Norman Sicily. The argument begins by recalling that the archetypal way of defining limits according to Classical Roman land surveyors was to beginab oriente. Many practices from Antiquity were discontinued in the Latin West, but the idea of starting with or from the East endured in many cases where boundaries were assigned cardinal directions. In the Byzantine Empire, the ‘Roman’ model was prescribed and emulated by Greek surveyors and scribes too. But in the Arab-Muslim Mediterranean, lands were defined with the southern limit first. This contrast forms the basis of a typology that can be tested against charter evidence in frontier zones – for example, in twelfth-century Sicily, which had been under Byzantine, Muslim and Norman rulers. It concludes that, under the Normans, private documents drawn up in Arabic began mainly with the southern limit following the ‘Islamic’ model. However, Arabic descriptions of crown lands started mainly in the ‘Romano-Byzantine’ way. These findings offer a higher resolution view of early Norman governance and suggest that such boundary definitions of the royal chancery could not have been based on older ones written in the Islamic period.
MONASTIC REFORM AND THE GEOGRAPHY OF CHRISTENDOM: EXPERIENCE, OBSERVATION AND INFLUENCE
Authors: Jotischky Andrew
Published: December 2012

Monastic reform is generally understood as a textually driven process governed by a renewed interest in early monastic ideals and practices in the eleventh and twelfth centuries, and focusing on the discourses of reformers about the Egyptian ‘desert fathers’ as the originators of monasticism. Historians have suggested that tropes about the desert, solitude, etc., drawn from early texts found their way into mainstream accounts of monastic change in the periodc. 1080–1150. This paper challenges this model by proposing that considerations of ‘reform’ must take into account parallel movements in Greek Orthodox monasticism and interactions of practice between the two monastic environments. Three case-studies of non-textually derived parallel practices are discussed, and the importance of the Holy Land as a source of inspiration for such practices is advanced in place of Egypt.
PEOPLE OF THE COVENANT AND THE ENGLISH BIBLE
Authors: Tadmor Naomi
Published: December 2012

The paper shows how the important theological and Anglo-biblical term ‘Covenant’ was formulated in the course of successive biblical translations, from the original Hebrew and Greek to the King Kames Bible. It suggests that the use of the term in English biblical versions reflected – and in turn propelled – the increasingly prominent Covenant theology. Once coined in the vernacular Scriptures, moreover, the term was applied to religious political alliances: from the Scottish Covenants of the 1590s to the English Solemn League and Covenant, 1644, studied in the paper.
Crab meat: a novel vehicle for E. coli O157 identified in an outbreak in South West England, August 2011
Authors: MATULKOVA P. , GOBIN M. , TAYLOR J. , OSHIN F. , O'CONNOR K. , OLIVER I.
Published: December 2012

In August 2011, we investigated an outbreak of Escherichia coli O157 in Plymouth, England, utilizing a case-control study and food traceback. Nine cases, eight laboratory-confirmed with E. coli O157 phage type 21/28 verocytotoxin 2 and one epidemiologically linked, had onsets from 30 July 2011 to 15 August 2011. We compared cases (n = 8) with controls (n = 28) of similar age and sex (median age 61 vs. 55 years, females 75% vs. 61%). Cases were 58 times more likely to have eaten crab (88% vs. 11%; odds ratio 58, 95% confidence interval 4-2700). Eight cases consumed crab sourced from the same supplier who was not registered with the local authority. This outbreak pointed to crab as a possible vehicle of E. coli O157 infection. We ensured the withdrawal of crab meat sourced from unregistered suppliers from food venues by 25 August 2011. We also emphasized the importance of only using registered suppliers to the food venues. Since then no further associated cases have been reported.
Public support for policies to improve the nutritional impact of the Supplemental Nutrition Assistance Program (SNAP)
Authors: Long Michael W , Leung Cindy W , Cheung Lilian WY , Blumenthal Susan J , Willett Walter C
Published: December 2012

Objective

To determine public attitudes towards federal spending on nutrition assistance programmes and support for policies to improve the nutritional impact of the Supplemental Nutrition Assistance Program (SNAP).

Design

Participants answered survey questions by telephone assessing support for SNAP spending and proposed programme policy changes.

Setting

USA.

Subjects

Survey of 3024 adults selected by random digit dialling conducted in April 2012, including 418 SNAP participants.

Results

A majority (77 %; 95 % CI 75, 79 %) of all respondents supported maintaining or increasing SNAP benefits, with higher support among Democrats (88 %; 95 % CI 86, 90 %) than Republicans (61 %; 95 % CI 58, 65 %). The public supported policies to improve the nutritional impact of SNAP. Eighty-two per cent (95 % CI 80, 84 %) of respondents supported providing additional benefits to programme participants that can only be used on healthful foods. Sixty-nine per cent (95 % CI 67, 71 %) of respondents supported removing SNAP benefits for sugary drinks. A majority of SNAP participants (54 %; 95 % CI 48, 60 %) supported removing SNAP benefits for sugary drinks. Of the 46 % (95 % CI 40, 52 %) of SNAP participants who initially opposed removing sugary drinks, 45 % (95 % CI 36, 54 %) supported removing SNAP benefits for sugary drinks if the policy also included additional benefits to purchase healthful foods.

Conclusions

The US public broadly supports increasing or maintaining spending on SNAP. The majority of respondents, including SNAP participants, supported policies to improve the nutritional impact of SNAP by restricting the purchase of sugary drinks and incentivizing purchase of healthful foods with SNAP benefits.
Petrology of the Apollo 12 highland component
Authors: Simon S. B. , Papike J. J.
Published: December 2012

Petrologic study of highland rock fragments handpicked from the Apollo 12 coarse fines confirms the KREEPy nature of the A‐12 highland components and the importance of norites and alkali anorthosites. This is in contrast to the calcic, non‐KREEPy A‐16 and A‐11 highland lithologies. The results add to the complexity of the igneous lunar highland rocks, which models for the formation of the lunar crust must take into account. A model involving moonwide differentiation followed by serial magmatism and heavy brecciation seems to be required. Results also show that non‐KREEPy highland materials are present at the A‐12 site and may represent Copernican and Imbrium ejecta, whereas the KREEPy materials may represent pre‐Imbrian terra, as at the A‐14 site.
Petrology and chemistry of Apollo 12 regolith breccias
Authors: Simon S. B. , Papike J. J. , Gosselin D. C. , Laul J. C.
Published: December 2012

Petrographic, mineral chemical, and bulk chemical data are reported for the three large Apollo 12 regolith breccias of the regolith breccia suite and for eight breccias handpicked from Apollo 12 coarse fines. Two samples formed from non‐KREEPy anorthositic regolith not presently found at the sampling site. Eight of the samples can be considered mixtures of local basalt and KREEP components, with minor anorthositic components. Mare:KREEP ratios indicated by chemical mixing models range from 86:7 to essentially endmember KREEP. One sample is unlike the others (FeO 23.7; MgO 21.7) and may be a new lithology or alternatively a nonrepresentative sample. Of the 11 samples studied, 5 appear to be of local origin, 3 are most likely exotic to the site, and results for 3 others are inconclusive. The anorthositic breccias formed from Apollo 16‐like regolith and may have been transported over several hundred kilometers from the non‐KREEPy highlands to the east. Alternatively, they may be of local origin, formed from the material beneath the Apollo 12 basalt flows.