bluuebunny/crossref_metadata_2025 huggingface dataset:
Transition metal phthalocyanines: Insight into the electronic structure from soft x-ray spectroscopy
Authors: Kroll T. , Kraus R. , Schönfelder R. , Aristov V. Yu. , Molodtsova O. V. , Hoffmann P. , Knupfer M.
Published: August 2012

Transition metal phthalocyanines (MPc's) are an interesting class of material, and their magnetic and electronic properties are determined by the orbital occupation of the transition metal 3d orbitals incorporated in the molecules center. Thus, the ground state configuration of the transition metal center is very important for a complete understanding of these materials. We present experimental data taken using x-ray absorption and x-ray photoemission spectroscopy together with a theoretical interpretation of MPc series with M=Zn, Cu, Ni, Co, Fe, and Mn. The combination of these methods allows us to narrow down possible dominating ground state configurations and shed a brighter light on the electronic structure of these complexes.
Analysis of edge density fluctuation measured by trial KSTAR beam emission spectroscopy system
Authors: Nam Y. U. , Zoletnik S. , Lampert M. , Kovácsik Á.
Published: August 2012

A beam emission spectroscopy (BES) system based on direct imaging avalanche photodiode (APD) camera has been designed for Korea Superconducting Tokamak Advanced Research (KSTAR) and a trial system has been constructed and installed for evaluating feasibility of the design. The system contains two cameras, one is an APD camera for BES measurement and another is a fast visible camera for position calibration. Two pneumatically actuated mirrors were positioned at front and rear of lens optics. The front mirror can switch the measurement between edge and core region of plasma and the rear mirror can switch between the APD and the visible camera. All systems worked properly and the measured photon flux was reasonable as expected from the simulation. While the measurement data from the trial system were limited, it revealed some interesting characteristics of KSTAR plasma suggesting future research works with fully installed BES system. The analysis result and the development plan will be presented in this paper.
Transition levels of defects in ZnO: Total energy and Janak's theorem methods
Authors: Chakrabarty Aurab , Patterson Charles H.
Published: August 2012

Transition levels of defects are commonly calculated using either methods based on total energies of defects in relevant charge states or energy band single particle eigenvalues. The former method requires calculation of total energies of charged, perfect bulk supercells, as well as charged defect supercells, to obtain defect formation energies for various charge states. The latter method depends on Janak's theorem to obtain differences in defect formation energies for various charge states. Transition levels of VZn, \documentclass[12pt]{minimal}\begin{document}$\text{V}_\text{O}$\end{document}VO, and VZnO vacancy defects in ZnO are calculated using both methods. The mean absolute deviation in transition level calculated using either method is 0.3 eV. Relative computational costs and accuracies of the methods are discussed.
Optimization of thermochromic VO2 based structures with tunable thermal emissivity
Authors: Voti R. Li , Larciprete M. C. , Leahu G. , Sibilia C. , Bertolotti M.
Published: August 2012

In this paper, we design and simulate VO2/metal multilayers to obtain a large tunability of the thermal emissivity of infrared (IR) filters in the typical mid wave IR window of many infrared cameras. The multilayer structure is optimized to realise a low emissivity filter at high temperatures useful for military purposes. The values of tunability found for VO2/metal multilayers are larger than the value for a single thick layer of VO2.
Comment on “On the consistency of the solutions of the space fractional Schrödinger equation” [J. Math. Phys. 53, 042105 (2012)]
Authors: Bayın Selçuk Ş.
Published: August 2012

Recently we have reanalyzed the consistency of the solutions of the space fractional Schrödinger equation found in a piecewise manner, and showed that an exact and a proper treatment of the relevant integrals prove that they are consistent. In this comment, for clarity, we present additional information about the critical integrals and describe how their analytic continuation is accomplished.
Modulated heterodyne light scattering set-up for measuring long relaxation time at small and wide angle
Authors: Leone Nancy , Villari Valentina , Micali Norberto
Published: August 2012

We present a simple, compact, and versatile experimental setup working in the heterodyne detection mode with modulation of the reference beam. The system is implemented with a collection optics based on a unimodal optical fiber coupler. This choice allows the heterodyne to be used in a wide range of scattering angles, even for very small ones, without losing the optical beating. The apparatus can be successfully used to study translational diffusive dynamics of dispersed particles at scattering angles smaller than 5° and it is suitable for exploring slow relaxation processes in sub-Hertz frequency domain, for example, in glass-forming systems. It is also possible to measure the electrophoretic mobility by applying an electric field into a charged particles solution.
A modularized pulse forming line using glass-ceramic slabs
Authors: Wang Songsong , Shu Ting , Yang Hanwu
Published: August 2012

In our lab, a kind of glass-ceramic slab has been chosen to study the issues of applying solid-state dielectrics to pulse forming lines (PFLs). Limited by the manufacture of the glass-ceramic bulk with large sizes, a single ceramic slab is hard to store sufficient power for the PFL. Therefore, a modularized PFL design concept is proposed in this paper. We regard a single ceramic slab as a module to form each single Blumlein PFL. We connect ceramic slabs in series to enlarge pulse width, and stack the ceramic Blumlein PFLs in parallel to increase the output voltage amplitude. Testing results of a single Blumlein PFL indicate that one ceramic slab contributes about 11 ns to the total pulse width which has a linear relation to the number of the ceramic slabs. We have developed a prototype facility of the 2-stage stacked Blumlein PFL with a length of 2 ceramic slabs. The PFL is dc charged up to 5 kV, and the output voltage pulse of 10 kV, 22 ns is measured across an 8 Ω load. Simulation and experiment results in good agreement demonstrate that the modularized design is reasonable.
Multiple magnetic transitions in Ag-substituted DyPt2
Authors: Arora Parul , Chattopadhyay M. K. , Sharath Chandra L. S. , Sharma V. K. , Roy S. B.
Published: August 2012

We show that the partial substitution of Ag in place of Pt in the cubic Laves phase ferromagnetic (below 9.2 K) compound DyPt2 leads to multiple temperature and field induced magnetic phase transitions. We study these phase transitions in details in a Dy(Pt0.94Ag0.06)2 alloy with the help of magnetization and specific heat measurements. One of the magnetic transitions produces an unusually sharp peak in the temperature dependence of heat capacity of Dy(Pt0.94Ag0.06)2, which is not observed in either of the parent compounds DyPt2 or DyAg2. The shape of this peak resembles those observed in the temperature dependence of heat capacity of the rare earth elements and some rare-earth based alloys and compounds across first order magnetic transitions accompanied by magneto-elastic effects and structural changes. The magnetic properties of Dy(Pt0.94Ag0.06)2 are analyzed in terms of the enhancement of crystal field effect and quadrupolar interactions. Large magneto-elastic coupling resulting from these interactions and changes in the electronic density of states near Fermi level because of the chemical substitution seem to introduce into the system the temperature and field induced multiple magnetic phase transitions mentioned above.
Photoluminescence study of β-Ga2O3 nanostructures annealed in different environments
Authors: Jangir R. , Porwal S. , Tiwari Pragya , Mondal Puspen , Rai S. K. , Ganguli Tapas , Oak S. M. , Deb S. K.
Published: August 2012

β-Ga2O3 nanostructures (nanowires, nanoribbons, and nanosheets) were synthesized via vapor transport method on gold coated silicon substrate in N2 ambient and these β-Ga2O3 nanostructures grown on silicon substrates were taken as the starting material to study the effect of annealing in the different environments (oxygen, water vapour, and ammonia solution) on the structural front and photoluminescence (PL) properties. The PL spectra of β-Ga2O3 nanostructures exhibit a UV-blue emission band whose intensity is strongly affected by the annealing in different environments. Annealing modifies the surface of the nanostructures by creating surface states which quench the PL by creating competitive nonradiative paths. This study also indicates the dominance of the formation of water induced surface states over ammonia induced surface states. The irreversible nature of these defects significantly affects the applicability of this system in moist high temperature environments.
Improved modeling of relativistic collisions and collisional ionization in particle-in-cell codes
Authors: Pérez F. , Gremillet L. , Decoster A. , Drouin M. , Lefebvre E.
Published: August 2012

An improved Monte Carlo collisional scheme modeling both elastic and inelastic interactions has been implemented into the particle-in-cell code CALDER [E. Lefebvre et al., Nucl. Fusion 43, 629 (2003)]. Based on the technique proposed by Nanbu and Yonemura [J. Comput. Phys. 145, 639 (1998)] allowing to handle arbitrarily weighted macro-particles, this binary collision scheme uses a more compact and accurate relativistic formulation than the algorithm recently worked out by Sentoku and Kemp [J. Comput. Phys. 227, 6846 (2008)]. Our scheme is validated through several test cases, demonstrating, in particular, its capability of modeling the electrical resistivity and stopping power of a solid-density plasma over a broad parameter range. A relativistic collisional ionization scheme is developed within the same framework, and tested in several physical scenarios. Finally, our scheme is applied in a set of integrated particle-in-cell simulations of laser-driven fast electron transport.
Generation of dust projectiles passing over an obstacle in the plasma sheath
Authors: Ticoş Cătălin M. , Stoica Daniel S. , Delzanno Gian Luca
Published: August 2012

Dust projectiles were produced in a radio-frequency plasma by increasing 6-fold the radio-frequency power put into the discharge. The initial static dust particles were observed to gain speed while moving away from the confining region and escaped from the inter-electrode space on a ballistic-like trajectory. Single-grain dynamics simulations indicated that the dust particles were accelerated by changes induced in the sheath electric field profile.
Pendent Nucleophiles on Coordination Complexes: Hydrogen-Bond Donor and Acceptor Ability
Authors: Clegg Jack K. , Harrowfield Jack M. , Kim Yang , Lee Young Hoon , Madalan Augustin , Thuéry Pierre , Woo Arim
Published: August 2012

Analysis of the crystal structures of a variety of transition metal complexes in which the ligands are hypodentate, thus providing pendent ammonio, amino, and/or hydroxy groups, has been conducted with the objective of defining the labile interactions of these pendent groups. In the case of pendent ammonio groups, not only do they appear to be good H-bond donors but they are frequently involved in contacts suggestive of hyperdenticity at N. For pendent amino and hydroxy groups, of particular interest in regard to their potential activity as nucleophiles, their H-bond acceptor ability frequently seems to be rather limited and it is unclear whether it can be related to either the nature or the charge on the bound metal cation.
Weathered Ilmenite: Diverse Mechanisms of Sintering and Association with Contaminants
Authors: Parks Terry C. , van Emden Bob , Webster Nathan A. S. , Merritt Richard R. , Graham Jim , Lincoln Frank J.
Published: August 2012

We briefly review the nature and provenance of extremely weathered ilmenite, then investigate its fate when it is 10 % of a blended feed in the reduction kilns of the Becher process. There it is bound, unintentionally and intermittently, in sinter, which is discarded. It takes with it discrete aluminosilicate grains as well as contaminants, adsorbed and occluded within the ilmenite. Two distinct sintering mechanisms are identified. A layered wall accretion forms purely by solid state reaction, and is thickest early in the kiln. It occasionally detaches under its own weight or is eroded, and is tolerated between scheduled shutdowns for maintenance. However, if the weathered ilmenite and accompanying silica escape earlier wall accretion, a transitory aluminosilicate melt may later promote sintering of this material within the bed, adhering catastrophically to constrictions and obstructions on the kiln wall. The mechanisms and controlling factors are discussed.
Bismuth(III) Thiobenzoates and their Activity against Helicobacter pylori
Authors: Andrews Philip C. , Ferrero Richard L. , Junk Peter C. , Maclellan Jonathan G. , Peiris Roshani M.
Published: August 2012

Two new substituted thiobenzoic acids, m-nitrothiobenzoic and m-sulfothiobenzoic acid, and six (four new) homo- and heteroleptic bismuth(iii) compounds derived from thiobenzoic acid and substituted thiobenzoic acid have been synthesised and fully characterised using both solvent free and solvent mediated methods; Bi(SC(=O)C6H5)3 (3), PhBi(SC(=O)C6H5)2 (4), Ph2Bi(SC(=O)C6H5) (5), Bi(SC(=O)C6H4-m-NO2)3 (6), PhBi(SC(=O)C6H4-m-NO2)2 (7), and PhBi(SC(=O)C6H4-m-SO3) (8). The solid-state structures of the previously reported Bi(SC(=O)C6H5)3 (3) and PhBi(SC(=O)]C6H5)2 (4) complexes have now been confirmed by X-ray crystallography. In the solid-state complex 3 forms a column-like polymeric structure resembling stacked bowls through pyramidal intermolecular Bi–S3 bonds of distance 3.359 Å, providing a Bi(iii) centre with a nine coordinate environment. Complex 4 forms discrete tetrameric units cemented by long intermolecular Bi–S (3.774 Å), Bi–O(= C) (3.030, 3.071 Å) and Bi–C bonds (3.627 Å). The complexes were assessed for their activity against three strains of Helicobacter pylori and all show a minimum inhibitory concentration of 6.25 µg mL–1, indicating that the high level of bactericidal activity is insensitive to the degree of substitution at the Bi(iii) centre.
Synthesis, Solid-state Structures, Solution Behaviour and Catalysis Studies of Nickel Complexes of Bis(benzimidazolin-2-ylidene)pyridine Pincer Ligands
Authors: MaGee Karen D. M. , Travers Guy , Skelton Brian W. , Massi Massimilliano , Payne Alan D. , Brown David H.
Published: August 2012

N-Heterocyclic carbene–nickel complexes with five- and four-coordinate geometries [(CNC)NiBr2] and [(CNC)NiBr]X (X = PF6 or BPh4) have been prepared with the pincer ligands 2,6-bis(N-octylbenzimidazolin-2-ylidene)pyridine and 2,6-bis(N-butyl-5,6-dimethoxybenzimidazolin-2-ylidene)pyridine. The addition of the n-octyl substituent significantly extends the solubility of the complexes and has allowed UV-vis solution studies of the complexes in dichloromethane and methanol. The four- and five-coordinate species exist in equilibrium in solution and this equilibrium has been explored by UV-vis studies. The complexes have also been characterized by NMR studies, and single crystal X-ray diffraction studies have been performed on [(CNC)NiBr2] (where CNC = 2,6-bis(N-octylbenzimidazolin-2-ylidene)pyridine) and [(CNC)NiBr]BPh4 (where CNC = 2,6-bis(N-butyl-5,6-dimethoxybenzimidazolin-2-ylidene)pyridine).
Synthesis and Coordination Chemistry of 2-(Di-2-pyridylamino)pyrimidine; Structural Aspects of Spin Crossover in an FeII Complex
Authors: Crees Rachel S. , Moubaraki Boujemma , Murray Keith S. , Sumby Christopher J.
Published: August 2012

2-(Di-2-pyridylamino)pyrimidine (L), a potentially ditopic tetradentate ligand, was synthesized from commercially available di-2-pyridylamine and 2-chloropyrimidine. Despite being capable of bridging two metal atoms with bidentate chelation of both metal centres, L prefers to chelate or bridge through the more basic pyridyl donors of the di-2-pyridylamine moiety. Mononuclear trans-[Fe(NCS)2(L)2] and [Cu(L)2(H2O)](BF4)2·H2O complexes, and a discrete [Ag2(L)4](PF6)2 metallo-macrocycle, were isolated and structurally characterized by X-ray crystallography. A mononuclear palladium complex [PdCl2(L)]·(solvate), where solvate = 1/2H2O or CH2Cl2, was also readily obtained in 71 % yield. One example of the ligand acting as a bis(bidentate) bridging ligand was observed in a dinuclear [(PdCl2)2(L)]·3/4H2O complex that was obtained only in very low yield (~3 %) from the reaction that produced [PdCl2(L)]·1/2H2O. trans-[Fe(NCS)2(L)2] undergoes a temperature-dependent high-spin–low-spin crossover at ~205 K that was observed by X-ray crystallography and magnetic measurements, and attempts were made to understand the structural basis of this process. Despite efforts to isolate examples of L bridging two iron(ii) centres, only the mononuclear trans-[Fe(NCS)2(L)2] species could be obtained.
Copper(II) and Palladium(II) Complexes with Cytotoxic and Antibacterial Activity
Authors: Krause-Heuer Anwen M. , Leverett Peter , Bolhuis Albert , Aldrich-Wright Janice R.
Published: August 2012

The synthesis of eight square pyramidal copper complexes with general structure [Cu(IL)(AL)H2O]2+, where IL represents various methylated 1,10-phenanthrolines, and AL represents either 1S,2S- or 1R,2R-diaminocyclohexane, is reported, with the complexes synthesised as both the perchlorate and chloride salts. The crystal structures of [Cu(1,10-phenanthroline)(1S,2S-diaminocyclohexane](ClO4)2·H2O and [Cu(5,6-dimethyl-1,10-phenanthroline)(1S,2S-diaminocyclohexane](ClO4)2·1.5H2O are reported. Four square planar palladium complexes with general structure [Pd(IL)(AL)]Cl2 have also been synthesised. These complexes were synthesised in order to investigate the structure–activity relationship against both cancer cell lines and bacterial cultures. The copper complexes display anticancer activity similar to cisplatin and 1,10-phenanthroline (phen) in the L1210 murine leukaemia cell line. Methylation of the phen increased the copper complex cytotoxicity by approximately four-fold, compared with the non-methylated complex. No significant difference in activity was observed by altering the chirality of the diaminocyclohexane ligand. The copper complexes demonstrated antibacterial activity against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli; however, high levels of toxicity (30–60 % of death) were observed in the nematode Caenorhabditis elegans. The copper complexes have also been shown to act as DNA nucleases, with the ability to cleave plasmid DNA in the presence of hydrogen peroxide. The palladium complexes all have half maximal inhibitory concentration (IC50) values of ~10 μM in the L1210 cell line, with no significant difference in the cytotoxicity of any of the compounds tested. Minimal antibacterial activity of the palladium complexes was observed.
Lanthanoid and Alkaline Earth Complexes Involving New Substituted Pyrazolates
Authors: Deacon Glen B. , Junk Peter C. , Urbatsch Aron
Published: August 2012

From the pyrazoles 3,5-di-(2′-furanyl)pyrazole (fu2pzH), 3-phenyl-5-(2′-thienyl)pyrazole (PhtpzH) and 3-(2′-furanyl)-5-(2′′-naphthyl)pyrazole (funappzH), a range of alkaline earth and lanthanoid pyrazolate complexes has been prepared by redox transmetallation/protolysis reactions between free metals, Hg(C6F5)2 and the pyrazoles, by reaction of I2‐activated metals with the pyrazoles, and in one case by a similar reaction of unactivated metal, in the donor solvents tetrahydrofuran (thf) and 1,2-dimethoxyethane (dme). Thus the divalent [Ca(Phtpz)2(thf)4], [Ba(Phtpz)2(thf)4] and [Ca(funappz)2(thf)4]·(thf) complexes, the heteroleptic [Yb(Phtpz)I(thf)4] and the trivalent [La(fu2pz)3(thf)3]·2thf complex have been prepared and structurally characterized, as well as the dme complexes [Yb(Phtpz)2(dme)2] and [Eu(Phtpz)3(dme)2]. Highlights include the first trans-[LnII(pz)I(thf)4] complex, a rare transoid [Ln(pz)2(dme)2] complex and a complex with both chelating and unidentate dme. In all cases, the Phtpz complexes exhibit pronounced positional disorder of the 2-thienyl and phenyl groups in the solid state, as do the two polymorphs of the parent pyrazole.
Copper(II) Complexes of Two New Pyridyl–Aliphatic Amine Ligands: Synthetic, Structural, EPR, and Magnetic Studies
Authors: Lee Young Hoon , Kristopo Hari , Woo Arim , Won Mi Seon , Hayami Shinya , Thuéry Pierre , Jung Ok-Sang , Lee Hong In , Kim Bok Jo , Lindoy Leonard F. , Kim Yang
Published: August 2012

Two new polyamine ligands, L1 and L2, incorporating pyridyl and aliphatic amine donor sites have been prepared and their reaction with copper(ii) yields the mono- and binuclear complexes [Cu(L1)](ClO4)2 (1) and [Cl2Cu(L2)CuCl(H2O)]ClO4 (2), respectively. The X-ray structure of 1 confirms that the five nitrogen donors of L1 are bound to the central copper ion to give a distorted square pyramidal coordination sphere. In 2, L2 acts as a bridging ligand with its N3-donor coordination domains separated by a m-xylylene spacer group. An unusual feature of this latter complex is that symmetrical L2 gives rise to non-equivalent coordination behaviour at the individual copper sites; while both sites display five-coordination with distorted square pyramidal arrangements, they differ in having N3Cl2- and N3ClO-donor atom sets, respectively. The electron paramagnetic resonance (EPR) spectra of both complexes are discussed. Variable temperature magnetic susceptibility data confirmed the absence of magnetic interactions in 1 while a weak antiferromagnetic interaction between copper(ii) centres occurs in 2.
The Chemistry of Transition Metal Ethyne-1,2-diyl Complexes
Authors: Griffith Christopher S. , Koutsantonis George A.
Published: August 2012

The chemistry and reactivity of ethyne-1,2-diyl compounds, LnM–CC–MLn, is reviewed. These complexes are simple analogues of organic alkynes, or dimetalloalkynes, and there appears to be no general route to the preparation of these complexes, except perhaps using acid/base methodology. Reactivity patterns, in general, mimic those of simple organic alkynes but have the added dimension of reactive M–C(sp) bonds that sometimes participate in the formation of multimetallic compounds with metal electrophiles.
Exploring phosphate effects on leaf flammability using a physical chemistry model
Authors: Scarff Fiona R. , Gray Brian F. , Westoby Mark
Published: August 2012

Some plants have traits that cause them to be more flammable than others, influencing wildfire spread and fire regimes. Some of these plant traits have been identified through laboratory-scale experiments. We built a numerical model that could quantify the extent of these effects on flammability. Here we present that model and use it to investigate the effect of phosphate content on the flammability of leaves. The model used finite-element methods and was based on heat transfer and thermal decomposition kinetics. Predictions were compared with three laboratory experiments involving ignition of leaf or cellulose samples. We then ran simulations of two situations through which leaf phosphate could influence wildfire spread: horizontal fire spread and crowning. The ignition time and maximum fuel gap that could be bridged by a flame front was predicted. Two key results emerged. (1) The importance of leaf phosphate in laboratory studies of ignition depends on the rate of sample heating, with the strongest effect under slow heating. (2) In the context of wildfires, phosphate was predicted to have modest effects compared with other plant traits influencing moisture content, leaf construction and angle of display.
An alternative fire regime zonation for Canada
Authors: Boulanger Yan , Gauthier Sylvie , Burton Philip. J. , Vaillancourt Marie-Andrée
Published: August 2012

The ability of national and multipurpose ecological classification systems to provide an optimal zonation for a fire regime is questionable. Using wildfire (>1 ha) point data for the 1980–99 period, we defined zones with a homogeneous fire regime (HFR) across Canada and we assessed how these differ from the National Ecological Framework for Canada (NEFC) units of corresponding scale, i.e. ecoprovinces. Two HFR zonations were produced through spatially constrained clustering of (i) 1600-km2 cells and (ii) the smallest units of the NEFC system, i.e. ecodistricts, using attributes for natural and anthropogenic fires. Thirty-three HFR zones were identified. HFR zonations showed smaller differences among each other than with NEFC ecoprovinces. Comparisons with ecoprovinces suggested general agreement of generalised fire regime values with HFR zones but with poor zone boundary correspondence. Ecoprovince zonation led to an overgeneralisation of fire regime estimates with less variation captured than by the HFR zonations, especially that using gridded fixed-area cells. Estimates of fire-return interval strongly differed between a priori and HFR zonations. The use of large-scale NEFC units or a zonation using its smallest units may constrain our ability to accurately quantify and portray fire regime variability across the country. The alternative empirical HFR zonation using gridded cells refines the location and nature of fire risk.
Topological symmetry groups of graphs in 3-manifolds
Authors: Flapan Erica , Tamvakis Harry
Published: August 2012

We prove that for every closed, connected, orientable, irreducible 3-manifold there exists an alternating group

A
n

A_n

which is not the topological symmetry group of any graph embedded in the manifold. We also show that for every finite group

G
G

there is an embedding

Γ
\Gamma

of some graph in a hyperbolic rational homology 3-sphere such that the topological symmetry group of

Γ
\Gamma

is isomorphic to

G
G

.
PROSPECTIVE THREE-DIMENSIONAL ANALYSIS OF STRUCTURE AND FUNCTION IN VITREOMACULAR ADHESION CURED BY PHARMACOLOGIC VITREOLYSIS
Authors: Tozer Kevin R. , Fink Wolfgang , Sadun Alfredo A. , Sebag Jerry
Published: August 2012

Purpose:

To prospectively characterize macular structure and function as assessed by combined three-dimensional spectral-domain optical coherence tomography and scanning laser ophthalmoscopy and 3D computer-automated threshold Amsler grid, respectively, in a patient undergoing pharmacologic vitreolysis for vitreomacular adhesion with tractional cysts.

Methods:

Combined 3D optical coherence tomography and scanning laser ophthalmoscopy measured macular volume and 3D computer-automated threshold Amsler grid quantified central visual field function by determining the absolute percent magnitude lost (cumulative value of total visual field loss over all tested levels) before and for a period of 6 months after pharmacologic vitreolysis for vitreomacular adhesion with a single intravitreal injection of microplasmin (125 μg; ThromboGenics).

Results:

Ocriplasmin pharmacologic vitreolysis released vitreomacular adhesion by 2 weeks and decreased macular volume from 0.32 μL to 0.15 μL by 1 year after injection. There was a concomitant 4-fold improvement in visual function as measured by 3D computer-automated threshold Amsler grid (percent of central visual field lost) and Snellen visual acuity improved from 20/200 to 20/40.

Conclusion:

For assessing macular function improvement in conjunction with structural reintegration after pharmacologic vitreolysis for vitreomacular adhesion, 3D computer-automated threshold Amsler grid is a useful tool. Both 3D measurements quantitatively characterized the resolution of this patient's vitreomacular adhesion, suggesting that this is a useful approach to quantifying macular structure and function as indices of the severity of disease and the response to therapy.
Functional Assessment of the Medicago truncatula NIP/LATD Protein Demonstrates That It Is a High-Affinity Nitrate Transporter
Authors: Bagchi Rammyani , Salehin Mohammad , Adeyemo O. Sarah , Salazar Carolina , Shulaev Vladimir , Sherrier D. Janine , Dickstein Rebecca
Published: August 2012

The Medicago truncatula NIP/LATD (for Numerous Infections and Polyphenolics/Lateral root-organ Defective) gene encodes a protein found in a clade of nitrate transporters within the large NRT1(PTR) family that also encodes transporters of dipeptides and tripeptides, dicarboxylates, auxin, and abscisic acid. Of the NRT1(PTR) members known to transport nitrate, most are low-affinity transporters. Here, we show that M. truncatula nip/latd mutants are more defective in their lateral root responses to nitrate provided at low (250 μm) concentrations than at higher (5 mm) concentrations; however, nitrate uptake experiments showed no discernible differences in uptake in the mutants. Heterologous expression experiments showed that MtNIP/LATD encodes a nitrate transporter: expression in Xenopus laevis oocytes conferred upon the oocytes the ability to take up nitrate from the medium with high affinity, and expression of MtNIP/LATD in an Arabidopsis chl1(nrt1.1) mutant rescued the chlorate susceptibility phenotype. X. laevis oocytes expressing mutant Mtnip-1 and Mtlatd were unable to take up nitrate from the medium, but oocytes expressing the less severe Mtnip-3 allele were proficient in nitrate transport. M. truncatula nip/latd mutants have pleiotropic defects in nodulation and root architecture. Expression of the Arabidopsis NRT1.1 gene in mutant Mtnip-1 roots partially rescued Mtnip-1 for root architecture defects but not for nodulation defects. This suggests that the spectrum of activities inherent in AtNRT1.1 is different from that possessed by MtNIP/LATD, but it could also reflect stability differences of each protein in M. truncatula. Collectively, the data show that MtNIP/LATD is a high-affinity nitrate transporter and suggest that it could have another function.
Global major histocompatibility Class II β (mh‐IIβ)‐polymorphism in Arctic charr Salvelinus alpinus
Authors: Conejeros P. , Power M. , Alekseyev S. , Dixon B.
Published: August 2012

This study explored the use of the gene encoding the β subunit of the major histocompatibility (MH) receptor as a population marker in Arctic charr Salvelinus alpinus. The use of this polymorphic marker allowed differentiation of the S. alpinus lineages previously defined using mitochondrial DNA (mtDNA) but also allowed differentiation between the populations studied within those lineages. The majority of the variation observed here occurred prior to the last glaciation event. Nevertheless, all S. alpinus populations were differentiated using both MH Class II β (mh‐IIβ) sequences and allelic frequencies. The fact that all the populations studied presented high rates of non‐synonymous: synonymous substitutions and high levels of interpopulation variation, suggested mh‐IIβ as an ideal marker to assess differentiation among S. alpinus populations in ways that may represent divergence both by genetic drift and natural adaptation to the local environment.
Remarkable karyotypic homogeneity in a widespread tropical fish species: Hoplosternum littorale (Siluriformes, Callichthyidae)
Authors: Almeida J. S. , Affonso P. R. A. M. , Dias A. L.
Published: August 2012

The first chromosomal data in Hoplosternum littorale from an isolated South American drainage in north‐eastern Brazil are presented. All specimens were characterized by a diploid number (2n) of 60 chromosomes divided into three metacentric, one submetacentric and 26 acrocentric pairs; single nucleolar organizer regions (NOR) on the sixth pair; centromeric and interstitial heterochromatin; GC‐rich sites on four large acrocentric chromosomes, including the NOR‐bearing pair, and 5S ribosomal genes at terminal region on short arms of two acrocentric pairs. These data are invariably similar to previous reports in H. littorale from distant localities throughout South America, which contrasts with the chromosomal diversity of Callichthyidae and reinforces the role of human activities on the dispersal and colonization of this fish.
Cryptic diversity in the mtDNA of the ornamental fish Carnegiella strigata
Authors: Schneider C. H. , Gross M. C. , Terencio M. L. , Porto J. I. R.
Published: August 2012

Mitochondrial DNA ( mtDNA) sequences of the marbled hatchetfish Carnegiella strigata, an ornamental fish exported from the Negro River, was examined to determine its genetic diversity and population structure in blackwater rivers (Negro and Uatumã Rivers) in the central Amazon. Analyses of a 646 bp fragment of the ATPase 6/8 mtDNA gene revealed two monophyletic lineages of C. strigata with considerable genetic distance between them (10–12%), suggesting that these lineages should not be considered a single stock. Furthermore, there were strong differences in the geographical distribution of the lineages. These results indicate a past association between drainages of the Negro and Uatumã Rivers. They also suggest that, in the Negro River, its main tributary, the Branco River, may act as a geographical barrier and potentially an ecological barrier between populations of the middle and lower portions of the river.
Pholcid spider molecular systematics revisited, with new insights into the biogeography and the evolution of the group
Authors: Dimitrov Dimitar , Astrin Jonas J. , Huber Bernhard A.
Published: August 2012

We analysed seven genetic markers sampled from 165 pholcids and 34 outgroups in order to test and improve the recently revised classification of the family. Our results are based on the largest and most comprehensive set of molecular data so far to study pholcid relationships. The data were analysed using parsimony, maximum‐likelihood and Bayesian methods for phylogenetic reconstruction. We show that in several previously problematic cases molecular and morphological data are converging towards a single hypothesis. This is also the first study that explicitly addresses the age of pholcid diversification and intends to shed light on the factors that have shaped species diversity and distributions. Results from relaxed uncorrelated lognormal clock analyses suggest that the family is much older than revealed by the fossil record alone. The first pholcids appeared and diversified in the early Mesozoic about 207 Ma ago (185–228 Ma) before the breakup of the supercontinent Pangea. Vicariance events coupled with niche conservatism seem to have played an important role in setting distributional patterns of pholcids. Finally, our data provide further support for multiple convergent shifts in microhabitat preferences in several pholcid lineages. Our findings suggest that both adaptive and non‐adaptive speciation may have played an important role in the diversification of pholcid lineages.
Initiation with menthol cigarettes and youth smoking uptake
Authors: Nonnemaker James , Hersey James , Homsi Ghada , Busey Andrew , Allen Jane , Vallone Donna
Published: August 2012

Aims

We aimed to assess whether young people who first tried menthol cigarettes were at greater risk of becoming established smokers and dependent on nicotine than young people who started smoking non‐menthol cigarettes.

Design

Cohort study using data from the American Legacy Longitudinal Tobacco Use Reduction Study (ALLTURS), a three‐wave longitudinal school‐based survey of middle school and high school students. Regression methods were used to assess the association between initiation with menthol cigarettes on risk of transitioning to established smoking or quitting from a non‐smoking state at baseline and on nicotine dependence score at wave 3.

Setting

The study was conducted in 83 schools in seven communities and five states in the United States.

Participants

Analyses were restricted to youth who participated in all three waves of ALLTURS, were younger than age 17 at baseline, and had initiated smoking during waves 1 or 2 of the study.

Measurements

Outcomes were indicators of a transition to established smoking or non‐smoking from non‐established smoking and a nicotine dependence score. The key explanatory variables were an indicator of initiation with menthol cigarettes and indicators for pattern of menthol use over time.

Findings

Initiating smoking with menthol cigarettes was associated with progression to established smoking [odds ratio (OR) = 1.80, confidence interval (CI): 1.02–3.16] and higher levels of nicotine dependence (β = 1.25, CI: 0.1–2.4).

Conclusion

Young people in the United States who start smoking menthol cigarettes are at greater risk of progression to regular smoking and nicotine dependence than are young people who start smoking non‐menthol cigarettes.
Usability testing of a prototype Phone Oximeter with healthcare providers in high‐ and low‐medical resource environments*
Authors: Hudson J. , Nguku S. M. , Sleiman J. , Karlen W. , Dumont G. A. , Petersen C. L. , Warriner C. B. , Ansermino J. M.
Published: August 2012

To increase the use of pulse oximetry by capitalise on the wide availability of mobile phones, we have designed, developed and evaluated a prototype pulse oximeter interfaced to a mobile phone. Usability of this Phone Oximeter was tested as part of a rapid prototyping process. Phase 1 of the study (20 subjects) was performed in Canada. Users performed 23 tasks, while thinking aloud. Time for completion of tasks and analysis of user response to a mobile phone usability questionnaire were used to evaluate usability. Five interface improvements were made to the prototype before evaluation in Phase 2 (15 subjects) in Uganda. The lack of previous pulse oximetry experience and mobile phone use increased median (IQR [range]) time taken to perform tasks from 219 (160–247 [118–274]) s in Phase 1 to 228 (151–501 [111–2661]) s in Phase 2. User feedback was positive and overall usability high (Phase 1 – 82%, Phase 2 – 78%).
Effects of the TRPV1 antagonist ABT‐102 on body temperature in healthy volunteers: pharmacokinetic/ pharmacodynamic analysis of three phase 1 trials
Authors: Othman Ahmed A. , Nothaft Wolfram , Awni Walid M. , Dutta Sandeep
Published: August 2012

Aim

To characterize quantitatively the relationship between ABT‐102, a potent and selective TRPV1 antagonist, exposure and its effects on body temperature in humans using a population pharmacokinetic/pharmacodynamic modelling approach.

Methods

Serial pharmacokinetic and body temperature (oral or core) measurements from three double‐blind, randomized, placebo‐controlled studies [single dose (2, 6, 18, 30 and 40 mg, solution formulation), multiple dose (2, 4 and 8 mg twice daily for 7 days, solution formulation) and multiple‐dose (1, 2 and 4 mg twice daily for 7 days, solid dispersion formulation)] were analyzed. nonmem was used for model development and the model building steps were guided by pre‐specified diagnostic and statistical criteria. The final model was qualified using non‐parametric bootstrap and visual predictive check.

Results

The developed body temperature model included additive components of baseline, circadian rhythm (cosine function of time) and ABT‐102 effect (Emax function of plasma concentration) with tolerance development (decrease in ABT‐102 Emax over time). Type of body temperature measurement (oral vs. core) was included as a fixed effect on baseline, amplitude of circadian rhythm and residual error. The model estimates (95% bootstrap confidence interval) were: baseline oral body temperature, 36.3 (36.3, 36.4)°C; baseline core body temperature, 37.0 (37.0, 37.1)°C; oral circadian amplitude, 0.25 (0.22, 0.28)°C; core circadian amplitude, 0.31 (0.28, 0.34)°C; circadian phase shift, 7.6 (7.3, 7.9) h; ABT‐102 Emax, 2.2 (1.9, 2.7)°C; ABT‐102 EC50, 20 (15, 28) ng ml−1; tolerance T50, 28 (20, 43) h.

Conclusions

At exposures predicted to exert analgesic activity in humans, the effect of ABT‐102 on body temperature is estimated to be 0.6 to 0.8°C. This effect attenuates within 2 to 3 days of dosing.
Applications and implications of manufactured nanoparticles in soils: a review
Authors: Pan B. , Xing B.
Published: August 2012

The environmental application and risk assessment of manufactured nanoparticles (MNPs) in soil greatly depend on our understanding of the interactions between MNPs and soil components. Because of the complexity of the soil system and the very early stage of MNP research in soil, our understanding of MNP behaviour in this system is very limited. This review summarizes the progress of research on MNPs and their implications for soils. Manufactured nanoparticles are applied deliberately for soil remediation and are also released unintentionally through various other pathways to soil. Their colloidal behaviour in the soil system is discussed by analysing the effect of dissolved organic matter, light irradiation, water chemistry conditions and biological processes. The methods currently used for modelling MNP leaching and transport are summarized and several requirements for model improvement are proposed. The current topics regarding the environmental risks of MNPs (such as identifying the toxicity of MNPs and their dissolved ions, evidence that MNPs may be taken up by soil organisms or the risks of other pollutants as affected by the presence of MNPs) are described. Future research directions are discussed and proposed.
Depletion of mboa‐7, an enzyme that incorporates polyunsaturated fatty acids into phosphatidylinositol (PI), impairs PI 3‐phosphate signaling in Caenorhabditis elegans
Authors: Lee Hyeon‐Cheol , Kubo Takuya , Kono Nozomu , Kage‐Nakadai Eriko , Gengyo‐Ando Keiko , Mitani Shohei , Inoue Takao , Arai Hiroyuki
Published: August 2012

Phosphatidylinositol (PI) is a constituent of biomembranes and a precursor of all phosphoinositides (PIPs). A prominent characteristic of PI is that its sn‐2 position is highly enriched in polyunsaturated fatty acids (PUFAs), such as arachidonic acid or eicosapentaenoic acid. However, the biological significance of PUFA‐containing PI remains unknown. We previously identified Caenorhabditis elegans (C. elegans) mboa‐7 as an acyltransferase that incorporates PUFAs into the sn‐2 position of PI. In this study, we performed an RNAi enhancer screen against PI kinases and phosphatases using mboa‐7 mutants that have a reduced PUFA content in PI. Among the genes tested, knockdown of vps‐34, a catalytic subunit of class III PI 3‐kinase that produces PI 3‐phosphate (PI3P) from PI, caused severe growth defects in mboa‐7 mutants. In both vps‐34 RNAi‐treated wild‐type worms and mboa‐7 mutants, the size of PI3P‐positive early endosomes was significantly decreased. We also performed an RNAi enhancer screen against PI3P‐related genes and found that, like knockdown of vps‐34, knockdown of autophagy‐related genes caused severe growth defects in mboa‐7 mutants. Finally, we showed that autophagic clearance of protein aggregates is impaired in mboa‐7 mutants. Taken together, these results suggest that the PUFA chain in PI has a role in some PI3P signaling.
A method to correct the wide discrepancy between Brunauer, Emmett and Teller water and N2 surface areas of adsorbents
Authors: Caurie Matthew
Published: August 2012

The Brunauer, Emmett and Teller (BET) method for estimating specific surface areas of adsorbents that is widely applied in food science and engineering operations has been shown to be expressed in wrong dimensional units and this explains the wide discrepancy, of several orders of magnitude, often observed between specific water and N2 surface areas of adsorbents when using the BET method. A method based on Caurie's unimolecular adsorption theory predicts the specific water and N2 surface areas in the same units and in their correct order of magnitude which for cornstarch equals, respectively, 258.88 and 169.86 m2 g−1 compared to BET estimates of 283.60 m2 g−1 for water and only 0.73 m2 g−1 for N2.
Effect of processing and storage on the fatty acid composition of n‐3 or n‐6 fatty acid‐enriched eggs
Authors: Botsoglou Evropi , Govaris Alexander , Pexara Andreana , Fletouris Dimitrios
Published: August 2012

Fresh eggs from hens fed diets supplemented with 4% linseed oil (LO) or sunflower oil (SO) were either directly submitted to pasteurisation, hard‐boiling or scrambling processing, or first submitted to refrigerated storage at 4 °C for 60 day and then to processing. Fresh LO eggs showed higher (P ≤ 0.05) proportions of monounsaturated fatty acids (MUFAs) and n‐3 polyunsaturated fatty acids (PUFAs), but lower (P ≤ 0.05) proportions of saturated fatty acids (SFAs), PUFAs and n‐6 PUFAs than the SO eggs. Storage decreased (P ≤ 0.05) the proportion of PUFAs and increased (P ≤ 0.05) that of MUFAs in egg yolks from both treatments. The pasteurisation process had no effect on the fatty acid composition of fresh eggs from both treatments, but increased (P ≤ 0.05) n‐6 PUFAs and decreased (P ≤ 0.05) n‐3 PUFAs in stored LO eggs. Hard‐boiling and scrambling modified the fatty acid composition of fresh and stored eggs from both treatments by decreasing (P ≤ 0.05) the proportion of PUFAs, particularly of the very long‐chain n‐3 eicosapentaenoic, docosapentaenoic and docosahexaenoic PUFAs. LO eggs showed a higher susceptibility to fatty acid modification upon processing as compared to the SO eggs.
Phenological mismatch strongly affects individual fitness but not population demography in a woodland passerine
Authors: Reed Thomas E. , Jenouvrier Stephanie , Visser Marcel E.
Published: August 2012

Populations are shifting their phenology in response to climate change, but these shifts are often asynchronous among interacting species. Resulting phenological mismatches can drive simultaneous changes in natural selection and population demography, but the links between these interacting processes are poorly understood.

Here we analyse 37 years of data from an individual‐based study of great tits (Parus major) in the Netherlands and use mixed‐effects models to separate the within‐ and across‐year effects of phenological mismatch between great tits and caterpillars (a key food source for developing nestlings) on components of fitness at the individual and population levels.

Several components of individual fitness were affected by individual mismatch (i.e. late breeding relative to the caterpillar food peak date), including the probability of double‐brooding, fledgling success, offspring recruitment probability and the number of recruits. Together these effects contributed to an overall negative relationship between relative fitness and laying dates, that is, selection for earlier laying on average.

Directional selection for earlier laying was stronger in years where birds bred on average later than the food peak, but was weak or absent in years where the phenology of birds and caterpillars matched (i.e. no population mismatch).

The mean number of fledglings per female was lower in years when population mismatch was high, in part because fewer second broods were produced. Population mismatch had a weak effect on the mean number of recruits per female, and no effect on mean adult survival, after controlling for the effects of breeding density and the quality of the autumnal beech (Fagus sylvatica) crop.

These findings illustrate how climate change‐induced mismatch can have strong effects on the relative fitness of phenotypes within years, but weak effects on mean demographic rates across years. We discuss various general mechanisms that influence the extent of coupling between breeding phenology, selection and population dynamics in open populations subject to strong density regulation and stochasticity.