bluuebunny/crossref_metadata_2025 huggingface dataset:
Computer simulation of bottle-brush polymers with flexible backbone: Good solvent versus theta solvent conditions
Authors: Theodorakis Panagiotis E. , Hsu Hsiao-Ping , Paul Wolfgang , Binder Kurt
Published: November 2011

By molecular dynamics simulation of a coarse-grained bead-spring-type model for a cylindrical molecular brush with a backbone chain of Nb effective monomers to which with grafting density σ side chains with N effective monomers are tethered, several characteristic length scales are studied for variable solvent quality. Side chain lengths are in the range 5 ⩽ N ⩽ 40, backbone chain lengths are in the range 50 ⩽ Nb ⩽ 200, and we perform a comparison to results for the bond fluctuation model on the simple cubic lattice (for which much longer chains are accessible, Nb ⩽ 1027, and which corresponds to an athermal, very good, solvent). We obtain linear dimensions of the side chains and the backbone chain and discuss their N-dependence in terms of power laws and the associated effective exponents. We show that even at the theta point the side chains are considerably stretched, their linear dimension depending on the solvent quality only weakly. Effective persistence lengths are extracted both from the orientational correlations and from the backbone end-to-end distance; it is shown that different measures of the persistence length (which would all agree for Gaussian chains) are not mutually consistent with each other and depend distinctly both on Nb and the solvent quality. A brief discussion of pertinent experiments is given.
New ab initio coupled potential energy surfaces for the Br(2P3/2, 2P1/2) + H2 reaction
Authors: Jiang Bin , Xie Changjian , Xie Daiqian
Published: November 2011

The three lowest (1A′, 2A′, and 1A′′) adiabatic potential energy surfaces (PESs) for the Br(2P) + H2 reactive system have been computed based on the multi-reference configuration interaction (MRCI) method including the Davidson's correction with a large basis set. These three adiabatic PESs have been transformed to a diabatic representation, leading to four coupling potentials. In addition, the spin-orbit matrix elements were also obtained using the Breit-Pauli Hamiltonian and the unperturbed MRCI wavefunctions in the Br + H2 channel and the transition state region. Consequently, six coupling potentials were obtained and their characteristics were extensively discussed. Nonadiabatic quantum dynamics calculations for this system have been realized with these realistic diabatic potentials instead of previous semi-empirical diabatic potentials. Based on two-state model nonadiabatic calculations for the Br(2P3/2, 2P1/2) + H2 reaction, the Br(2P1/2) + H2 reaction was found to show less reactivity than the Br(2P3/2) + H2 reaction at collision energies beyond the threshold of the Br(2P3/2) + H2 reaction. Our results are consistent with the previous studies on the XH2 (X = F, Cl) system, which indicate that the adiabatically forbidden channel is dominant at low energies in the open-shell halogen atom plus H2 reactions.
State-to-state quantum dynamics of the N(4S) + OH(X 2Π) → H(2S) + NO(X 2Π) reaction
Authors: Xie Changjian , Li Anyang , Xie Daiqian , Guo Hua
Published: November 2011

Quantum state-to-state dynamics for the N(4S) + OH(X 2Π) → H(2S) + NO(X 2Π) reaction is reported on an accurate ab initio potential energy surface of the lowest triplet electronic state (a3A″) of HNO/HON. It was found that the reaction is dominated by long-lived resonances supported by the HNO and HON wells. Significant non-reactive scattering was observed, indicating substantial deviations from the statistical limit. Due to the large exothermicity of the reaction, the NO product has hot internal state distributions: its rotational state distribution is inverted and peaks near the highest accessible rotational level; and its vibrational state distribution extends to υ = 10 and decays monotonically with the vibrational quantum number. In particular, the predicted product vibrational distribution is in reasonably good agreement with experiment. The calculated differential cross section is dominated by scattering in both the forward and backward directions, consistent with the formation of reaction intermediates.
Optimization of a genetic algorithm for searching molecular conformer space
Authors: Brain Zoe E. , Addicoat Matthew A.
Published: November 2011

We present two sets of tunings that are broadly applicable to conformer searches of isolated molecules using a genetic algorithm (GA). In order to find the most efficient tunings for the GA, a second GA – a meta-genetic algorithm – was used to tune the first genetic algorithm to reliably find the already known a priori correct answer with minimum computational resources. It is shown that these tunings are appropriate for a variety of molecules with different characteristics, and most importantly that the tunings are independent of the underlying model chemistry but that the tunings for rigid and relaxed surfaces differ slightly. It is shown that for the problem of molecular conformational search, the most efficient GA actually reduces to an evolutionary algorithm.
Large-scale symmetry-adapted perturbation theory computations via density fitting and Laplace transformation techniques: Investigating the fundamental forces of DNA-intercalator interactions
Authors: Hohenstein Edward G. , Parrish Robert M. , Sherrill C. David , Turney Justin M. , Schaefer Henry F.
Published: November 2011

Symmetry-adapted perturbation theory (SAPT) provides a means of probing the fundamental nature of intermolecular interactions. Low-orders of SAPT (here, SAPT0) are especially attractive since they provide qualitative (sometimes quantitative) results while remaining tractable for large systems. The application of density fitting and Laplace transformation techniques to SAPT0 can significantly reduce the expense associated with these computations and make even larger systems accessible. We present new factorizations of the SAPT0 equations with density-fitted two-electron integrals and the first application of Laplace transformations of energy denominators to SAPT. The improved scalability of the DF-SAPT0 implementation allows it to be applied to systems with more than 200 atoms and 2800 basis functions. The Laplace-transformed energy denominators are compared to analogous partial Cholesky decompositions of the energy denominator tensor. Application of our new DF-SAPT0 program to the intercalation of DNA by proflavine has allowed us to determine the nature of the proflavine-DNA interaction. Overall, the proflavine-DNA interaction contains important contributions from both electrostatics and dispersion. The energetics of the intercalator interaction are are dominated by the stacking interactions (two-thirds of the total), but contain important contributions from the intercalator-backbone interactions. It is hypothesized that the geometry of the complex will be determined by the interactions of the intercalator with the backbone, because by shifting toward one side of the backbone, the intercalator can form two long hydrogen-bonding type interactions. The long-range interactions between the intercalator and the next-nearest base pairs appear to be negligible, justifying the use of truncated DNA models in computational studies of intercalation interaction energies.
Spectroscopic characteristics of Dy3+ doped Y3Al5O12 transparent ceramics
Authors: Lupei A. , Lupei V. , Gheorghe C. , Ikesue A. , Enculescu M.
Published: November 2011

The spectroscopic characteristics of Dy3+ in YAG (Y3Al5O12) transparent ceramics prepared by solid state synthesis were investigated, with special attention to the visible (yellow, blue) emissions that could be pumped directly by the new developed blue–violet or near UV laser diodes. The absorption and emission spectra, recorded at different temperatures from 10 to 300 K, were analyzed and relevant new parameters, improved energy level scheme, temperature effects, intensity parameters based on Judd-Ofelt theory and radiative transition rates, branching ratios, etc., were estimated and the data are compared with previous reports on garnet single crystals. The potential of the Dy3+: YAG transparent ceramics for yellow or blue laser emission is discussed.
Construction of a disorder variable from Steinhardt order parameters in binary mixtures at high densities in three dimensions
Authors: Kawasaki Takeshi , Onuki Akira
Published: November 2011

Using molecular dynamics simulation, we investigate the structural disorder in crystal, polycrystal, and glass in a Lennard-Jones binary mixture composed of N1 + N2 = 4096 particles at a low temperature in three dimensions. The size ratio σ2/σ1 between the large and small particles is either 1.2 or 1.4. The crossovers among these states occur, as the composition of the large particles c = N2/(N1 + N2) is varied. We define a disorder variable Dj for each particle j in terms of local bond order parameters based on spherical harmonics (Steinhardt order parameters). Stacking faults and grain boundaries in fcc polycrystal and mesoscopic structural heterogeneity in glass are then visualized. At small c, disturbances of large particles is stronger for larger σ2/σ1. At large c, the transition between glass and polycrystal occurs nearly discontinuously at c = cc ∼ 0.8. At σ2/σ1 = 1.4, microphase separation occurs in polycrystal states with c > cc, where fcc crystal grains comprising the large particles are enclosed by amorphous layers composed of the two particle species.
Charge transfer dynamics of 3,4,9,10-perylene-tetracarboxylic-dianhydride molecules on Au(111) probed by resonant photoemission spectroscopy
Authors: Cao Liang , Wang Yu-Zhan , Chen Tie-Xin , Zhang Wen-Hua , Yu Xiao-Jiang , Ibrahim Kurash , Wang Jia-Ou , Qian Hai-Jie , Xu Fa-Qiang , Qi Dong-Chen , Wee Andrew T. S.
Published: November 2011

Charge transfer dynamics across the lying-down 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) organic semiconductor molecules on Au(111) interface has been investigated using the core-hole clock implementation of resonant photoemission spectroscopy. It is found that the charge transfer time scale at the PTCDA/Au(111) interface is much larger than the C 1s core-hole lifetime of 6 fs, indicating weak electronic coupling between PTCDA and the gold substrate due to the absence of chemical reaction and/or bonding.
A compact SQUID-detected magnetic resonance imaging system under microtesla field in a magnetically unshielded environment
Authors: Chen Hsin-Hsien , Yang Hong-Chang , Horng Herng-Er , Liao Shu-Hsien , Yueh Shieh , Wang Li-Min
Published: November 2011

In this study, we present a compact and sensitive SQUID-detected nuclear magnetic resonance spectrometer and imager (NMR/MRI) using flux coupling in microtesla fields. The pre-polarization coil, measuring coil, pulsed coil, and gradient coils were set up inside a three-layer aluminum box while the SQUID-detector was shielded with a high-Tc superconducting vessel. A compensation field was applied to improve the field homogeneity in magnetically unshielded environments. The spin precession of protons was inductively coupled to the SQUID magnetometer via a resonant flux transformer. We obtained a signal-to-noise ratio of 120 in one measurement, a spectral resolution better than 1 Hz, and a spatial resolution of 1.3 mm in the images.
Controlling magnetic properties of Fe3+ doped indium oxide nanocubes by atmospheric annealing method
Authors: Sun Qingbo , Zeng Yuping , Jiang Dongliang
Published: November 2011

Fe3+ doped In2O3 nanocubes with different doped concentrations (from 5 at. % to 15 at. %) were prepared by direct solvothermal method and 10 at. % doped samples were then annealed under atmospheric conditions to investigate effects of annealing temperatures on their magnetic properties. The magnetic transitions from paramagnetic to ferromagnetic and again to paramagnetic occurred with increments of annealing temperatures, since the oxygen vacancies affected exchanges of two neighboring Fe3+ ions. Moreover, their magnetic properties were further demonstrated to be intrinsic by X-ray diffraction, high-resolution transmission electron microscopy, and X-ray energy dispersive spectrometry.
Enhanced diffusion in conic channels by means of geometric stochastic resonance
Authors: Vazquez M. V. , Valdes-Parada F. J. , Dagdug L. , Alvarez-Ramirez J.
Published: November 2011

Geometric stochastic resonance of Brownian particles diffusing across a converging conic channel subject to oscillating forces is studied in this paper. Conic channel geometries have been previously considered as a model for transport of particles in biological membranes, zeolites, and nanostructures. For this system, a broad excess peak of the effective diffusion above the free diffusion limit is exhibited over a wide range of frequencies, suggesting a synchronization effect in the confining geometry as particles respond to the periodic modulation of the external force. This indicates that the geometric stochastic resonance effect with unbiased ac forces can be exploited for improving the transport of particles in complex geometries.
Oscillatory antiferromagnetic interlayer exchange coupling in Co2Fe(Al0.5Si0.5)/Ag/Co2Fe(Al0.5Si0.5) films and its application to trilayer magnetoresistive sensor
Authors: Nakatani T. M. , Mitani S. , Furubayashi T. , Hono K.
Published: November 2011

We report oscillatory antiferromagnetic (AFM) interlayer exchange coupling (IEC) in a trilayer film with Co2Fe(Al0.5Si0.5) (CFAS) Heusler alloy ferromagnetic layers and a Ag spacer layer. The AFM-IEC was observed only in the films annealed at >400 °C, suggesting the enhancement of the interfacial spin-dependent scattering by improved B2 order in the CFAS film is its origin. Using the AFM coupled trilayer, we demonstrated a scissors-type trilayer CPP-GMR device with relatively large ΔRA of 4.5 mΩ μm2 and MR ratio of 24%.
Kerr-driven nonlinear refractive index of air at 800 and 400 nm measured through femtosecond laser pulse filamentation
Authors: Geints Yu. E. , Kabanov A. M. , Zemlyanov A. A. , Bykova E. E. , Bukin O. A. , Golik S. S.
Published: November 2011

The filamentation dynamics of 15 GW femtosecond laser pulses at 800 and 400 nm wavelengths upon their tight focusing in air is studied experimentally. The spatial position and extent of plasma channel formed within the filamentation zone as a function of laser pulse power are investigated. The processing of the experimental data according to the Marburger formula by J. H. Marburger [Prog. Quantum. Electron. 4, 35 (1975)] and the dispersion relations for air cubic nonlinearity has allowed to estimate the effective value of the Kerr-driven air refractive index on 400 nm as 5.36 × 10−19 cm2/W with a 5% error.
Effect of magnetic field and pressure on charge-orbital ordering in Pr(Sr1−xCax)2Mn2O7 (x = 0.4 and 0.9) single crystals
Authors: Thiyagarajan R. , Deng Guochu , Arumugam S. , Mohan Radheep D. , Devarajan U. , Murugeswari A. , Mandal P. , Pomjakushina Ekaterina , Conder Kazimierz
Published: November 2011

The magnetic properties of half-doped Pr(Sr1−xCax)2Mn2O7 (x = 0.4 and 0.9) single crystals have been investigated under magnetic field (H) and hydrostatic pressure (P). Analysis of magnetization data reveals that, for x = 0.4 sample, only one charge-orbital ordering (CO-OO) transition occurs which decreases very slowly with P, while the antiferromagnetic ordering transition shifts towards higher temperature with the increase of P. For x = 0.9 sample, with the increase of P, the low-temperature CO-OO transition temperature decreases and the high-temperature CO-OO transition remains unaffected while antiferromagnetic and structural transition temperatures increase.
Low-damage milling of an amino acid thin film with cluster ion beam
Authors: Hada Masaki , Ibuki Sachi , Hontani Yusaku , Yamamoto Yasuyuki , Ichiki Kazuya , Ninomiya Satoshi , Seki Toshio , Aoki Takaaki , Matsuo Jiro
Published: November 2011

In this work, we characterized the surface damage layer and sputtering yield of polycrystalline L-leucine films before and after irradiation with Ar cluster or monomer ion beams with x ray photoelectron spectroscopy and ellipsometry. Irradiation with Ar monomer ion beams induced heavy damage on the surface of L-leucine films, such as bond breaking and carbonization. In contrast, no significant surface damage was observed in the films irradiated with Ar cluster ion beams. The sputtering yield of L-leucine decreased dramatically with increasing fluence of monomer Ar ions and approached the value of the sputtering yield of graphite; but under irradiation with Ar cluster ion beams, the sputtering yield remained constant with fluence. The differences in sputtering yield behavior were explained in relation with the surface damage layer on organic materials. Thus, cluster ion beams could potentially be used to mill down biological materials without significant damage on the surface and could contribute to various applications in the analysis and processing of life matter.
Electrical properties of HfO2/La2O3 gate dielectrics on Ge with ultrathin nitride interfacial layer formed by in situ N2/H2/Ar radical pretreatment
Authors: Lin Ming-Ho , Lan Chun-Kai , Chen Chih-Chiao , Wu Jyun-Yi
Published: November 2011

In situ N2/H2/Ar radical pretreatment on p-type Ge (100) with HfO2/La2O3 high-κ gate oxide was investigated by remote rf plasma on radical-assisted atomic layer deposition. The interfacial LaGeOxNy formation and Ge outdiffusion were also investigated by x-ray photoelectron spectroscopy and transmission electron microscopy. The high-κ MOS device with an ultrathin LaGeOxNy interfacial layer shows good electrical characteristics, including larger κ value, smaller equivalent oxide thickness, lower leakage current density, smaller C-V hysteresis, and lower interface-state density. The involved mechanism lies in that the LaGeOxNy interfacial layer can effectively block Ge outdiffusion, thus improving the high-κ films/Ge interface quality.
Large rectifying leakage current in Pt/BaTiO3/Nb:SrTiO3/Pt structure
Authors: Zhang T. J. , Pan R. K. , Ma Z. J. , Duan M. G. , Wang D. F. , He M.
Published: November 2011

20-nm-thickness epitaxial BaTiO3 (BTO) thin films were prepared on the Nb-doped SrTiO3 single-crystal substrates by RF magnetron sputtering technology. The rectifying characteristic current-voltage curves were observed and was discussed using the Schottky barrier model taking into account the movement of oxygen vacancies. The leakage current mechanisms were interpreted by the Schottky emission and Poole-Frenkel emission near the Pt/BTO interface at lower bias and higher bias, respectively.
Wet nanogranular materials: Colloidal glass and gel
Authors: Yuan Chia-Nan , Li Yueh-Feng , Sheng Yu-Jane , Tsao Heng-Kwong
Published: November 2011

Partially wet granular medium is a mouldable material due to capillary cohesion and its behavior plays key roles in geophysics. However, completely wet nanogranules may also demonstrate mouldable properties via van der Waals attraction and they exhibit colloidal glass or gel characteristics, depending on the solvent. As solvent-enhanced attractions prevail, phase separation is observed and nanogranular gel can be obtained. In contrast, as cage effects dominate, the stable slurry is seen and the nanogranular glass can be prepared. Upon surfactant addition, however, the arrested glass state changes into colloidal gel due to the formation of hydrogen bonds between nanogranules.
Diamond processing by focused ion beam—surface damage and recovery
Authors: Bayn I. , Bolker A. , Cytermann C. , Meyler B. , Richter V. , Salzman J. , Kalish R.
Published: November 2011

The nitrogen vacancy color center (NV−) in diamond is of great interest for photonic applications. Diamond nano-photonic structures are often implemented using focused-ion-beam (FIB) processing, leaving a damaged surface which has a detrimental effect on the color center luminescence. The FIB processing effect on single crystal diamond surfaces and their photonic properties is studied by time of flight secondary ion mass spectrometry and photoluminescence. Exposing the processed surface to hydrogen plasma, followed by chemical etching, drastically decreases implanted Ga concentration, resulting in a recovery of the NV− photo-emission and in a significant increase of the NV−/NV0 ratio.
Water adsorption on graphene/Pt(111) at room temperature: A vibrational investigation
Authors: Politano A. , Marino A. R. , Formoso V. , Chiarello G.
Published: November 2011

Water interaction with quasi-freestanding graphene deposited on Pt(111) has been investigated by using vibrational spectroscopy. Loss measurements show that water molecules dosed at room temperature can dissociate giving rise to C-H bonds. The formation of the C-H bonds strongly attenuates the optical phonons of the graphene sheet. On the other hand, at 100 K water has been found to adsorb only in molecular state. Present findings should be taken into account in engineering graphene-based devices which should work at atmospheric pressure and at room temperature.
Demographic and risk analyses of spiny dogfish (Squalus suckleyi) in the Gulf of Alaska using age- and stage-based population models
Authors: Tribuzio Cindy A. , Kruse Gordon H.
Published: November 2011

Demographic models are useful tools for assessing data-limited species and may be an appropriate alternative to cohort analyses for sharks due to their long-lived, slow-growing nature. In this study, age- and stage-based demographic analyses were conducted to examine the intrinsic rebound potential (r) and potential risk of fishing for spiny dogfish (Squalus suckleyi) in the Gulf of Alaska. Monte Carlo simulations were conducted to incorporate input parameter uncertainty. For an unfished population, r was estimated to be 0.02–0.03 year–1. Fishing mortalities (F) of F = 0.04 and 0.03 (age- and stage-based models respectively), resulted in r = 0, indicating that populations fished at higher F are not sustainable. Harvest strategies targeting juveniles (age-based model) and subadults (stage-based model) caused the highest risk of the population falling below defined thresholds (BMSY, B40% and B50%) after 20 years. The age- and stage-based models provided similar estimates of r and sustainable fishing mortality, suggesting that the stage-based model is an appropriate substitute for the age-based model in this case. S. suckleyi and the closely related S. acanthias are often harvested around the world and this modelling approach could be useful to the management of these species and other sharks where data is limited.
Influence of hamstring extensibility on sagittal spinal curvatures and pelvic tilt in highly trained young kayakers
Authors: López‐Miñarro Pedro A. , Muyor José M. , Alacid Fernando
Published: November 2011

Objective: To evaluate the influence of hamstring extensibility on spinal and pelvic postures adopted by young paddlers in their kayaks.

Methods: Sixty‐eight young elite kayakers were recruited for the study (mean value 15.23, s=0.68 years). Thoracic and lumbar curvatures and pelvic position were evaluated with a Spinal Mouse system in standing position and in the boat (seated in the kayak with the paddle resting on their thighs, right entry position and left entry position). Hamstring muscle extensibility was determined in both legs by passive straight leg raise test (PSLR). The sample was divided into two groups with regard to straight leg raise angle (Group A, PSLR < 80°, n=32, and group B, PSLR ≥ 80°, n=32).

Results: Paddlers with lower extensibility presented higher thoracic and lumbar flexion and a more posterior pelvic tilt in the kayak in all three positions. However, no significant differences were found between the groups when standing.

Conclusion: The results suggest that lower hamstring extensibility is related to increased spinal flexion and posterior pelvic tilt, which can overload the spine during paddling training. A systematic and intensive stretching programme to improve hamstring muscle extensibility should be incorporated into the training activities of paddlers.
Internal plasma pressure peaking in low-shear open and closed magnetic confinement systems
Authors: Tsventoukh M.M.
Published: November 2011

The plasma convective (flute-interchange) stability for low magnetic shear systems, with a low collisionality and a low beta, is considered in terms of the necessary and sufficient collisionless kinetic criterion. The magnetic confinement systems under consideration are axially symmetric mirrors equipped with outer divertors and inner field reversing rings (cusps, internal rings, high-beta cells) and closed multimirror traps. A simple approach is proposed for plasma stabilization resulting in a substantial steepening of the critical pressure profile. The essence is the combination of the plasma stabilization by a strong and an alternating-sign field-line curvature. Axially symmetric tandem mirror systems composed of a mirror device having an outer divertor and an inner field reversing ring are shown to have an internal radially peaked stable pressure profile. Bumpy tori are also shown to have an internally peaked stable pressure profile.
A cone theorem for nef curves
Authors: Lehmann Brian
Published: November 2011

Following ideas of V. Batyrev, we prove an analogue of the Cone Theorem for the closed cone of nef curves: an enlargement of the cone of nef curves is the closure of the sum of a

K

X

K_{X}

-non-negative portion and countably many

K

X

K_{X}

-negative coextremal rays. An example shows that this enlargement is necessary. We also describe the relationship between

K

X

K_{X}

-negative faces of this cone and the possible outcomes of the minimal model program.
First Report of Leaf Spot Disease on Schisandra chinensis Caused by Phoma glomerata in China
Authors: Wang X. , Wang J. , Gao J. , Yang L.
Published: November 2011

Schisandra chinensis (Turcz.) Baill is a perennial liana belonging to the Schisandra genus of the family Magnoliaceae, which is cultivated in China as an important medicinal plant. In the summer of 2008, we observed a previously unknown foliar disease on the schisandras in Jingyu and Antu counties and the cities of Ji'an and Hunchun in Jilin Province. Symptoms appeared on the apex, margin, and center of leaves. The infection initially manifested as pale brown, small, necrotic spots on the leaves. Subsequently, these lesions became grayish brown in the center and dark brown with slight protuberances at the margins. Finally, these lesions developed concentric rings with a clear boundary separating them from the healthy tissue, were round to elliptical or irregular in shape, and had a diameter of 3 to 5 mm. In severely infected leaves, these spots eventually covered the entire leaf. Black spots (pycnidia) were produced on the infected leaf tissues in a humid environment. Fungus from infected leaf tissues was isolated on potato dextrose agar. The cultures were initially pale brown and turned dark green with age. Embedded pycnidia were generally formed after 5 days. The pycnidia were agglutinating, globose to subglobose, and measured 60.0 to 212.0 × 33.6 to 268.0 μm. Abundant conidia (4.06 to 7.2 × 1.65 to 3.53 μm) exhibiting zero to three oil droplets were produced by an 8-day-old colony; these conidia were ovoid or ellipsoidal, colorless, and aseptate; they were similar to conidia of Phoma glomerata. The internal transcribed spacer (ITS) sequence of rDNA of the isolated pathogenic strain (PG11; GenBank Accession No. GU724511) had 100% identity to P. glomerata (GenBank Accession No. HM769279). Therefore, the pathogen was identified as P. glomerata (Corda) Wollenw. & Hochapfel on the basis of morphology and ITS sequence data. To validate Koch's postulates, schisandra leaves were spray inoculated with a 2.5 × 105 conidia/ml suspension of the isolated pathogen. An equal number of healthy plants were inoculated with sterile water (control). After inoculation, 10 plants were covered with plastic bags for 3 days and maintained in a growth chamber at 25°C. After 8 days, all inoculated plants showed symptoms identical to those observed on the schisandra leaves infected in the field, whereas the controls did not show any symptoms. Reisolation of the fungi from lesions of inoculated leaves confirmed that the causal agent was P. glomerata. Diseases caused by P. glomerata have been reported on some plants (1,2). However, to our knowledge, this is the first report of leaf spot disease caused by P. glomerata on S. chinensis in China as well as in the world.

References: (1) J. S. Chohan et al. Trans. Br. Mycol. Soc. 75:509, 1980. (2) T. Thomidis et al. Eur. J. Plant Pathol. 131:171,2011.
Cationic Surfactants: Potential Surface Disinfectants to Manage Agrobacterium tumefaciens Biovar 1 Contamination of Grafting Tools
Authors: Yakabe L. E. , Parker S. R. , Kluepfel D. A.
Published: November 2011

Nursery production of walnut seedlings is a 2-year process, during which crown gall, caused by Agrobacterium tumefaciens, often develops at grafting wounds. In this study, the spread of crown gall via contaminated tools and the efficacy of several disinfectants against A. tumefaciens were demonstrated. The cationic surfactants benzalkonium chloride (BC), cetyltrimethylammonium bromide (CTAB), and Physan 20 eliminated 100% of the A. tumefaciens population in water suspensions treated at 7, 5, and 2 ppm, respectively. Sodium hypochlorite eliminated 100% of the A. tumefaciens population at 0.5 ppm. Sodium hypochlorite efficacy, however, was reduced by 64% in the presence of total solids (0.7 g/ml) which are commonly found in field situations. At similar concentrations of total solids, the efficacy of cationic surfactants decreased, on average, by only 13%. The minimum effective treatment needed to eliminate A. tumefaciens on infested scalpels was a 5-s exposure to BC or CTAB at 5,000 ppm (0.5%). Infested scalpels treated with BC or CTAB at less than 5,000 ppm caused gall formation in 14 ± 7% of cuts made on Datura stramonium stems. This was significantly less than the tumor incidence (100%) in cuts made with inoculated blades not treated BC or CTAB.
Eurasian jays (
Garrulus glandarius
) overcome their current desires to anticipate two distinct future needs and plan for them appropriately
Authors: Cheke Lucy G. , Clayton Nicola S.
Published: November 2011

Western scrub-jays (
Aphelocoma californica
) have been shown to overcome present satiety to cache food they will desire in the future. Here, we show that another corvid, the Eurasian jay (
Garrulus glandarius
), can distinguish between two distinct future desires and plan for each appropriately, despite experiencing a conflicting current motivation. We argue that these data address the criticisms of previous work, and suggest a way in which associative learning processes and future-oriented cognition may combine to allow prospective behaviour.
Ranavirus: past, present and future
Authors: Lesbarrères D. , Balseiro A. , Brunner J. , Chinchar V. G. , Duffus A. , Kerby J. , Miller D. L. , Robert J. , Schock D. M. , Waltzek T. , Gray M. J.
Published: November 2011

Emerging infectious diseases are a significant threat to global biodiversity. While historically overlooked, a group of iridoviruses in the genus
Ranavirus
has been responsible for die-offs in captive and wild amphibian, reptile and fish populations around the globe over the past two decades. In order to share contemporary information on ranaviruses and identify critical research directions, the First International Symposium on Ranaviruses was held in July 2011 in Minneapolis, MN, USA. Twenty-three scientists and veterinarians from nine countries examined the ecology and evolution of ranavirus–host interactions, potential reservoirs, transmission dynamics, as well as immunological and histopathological responses to infection. In addition, speakers discussed possible mechanisms for die-offs, and conservation strategies to control outbreaks.
A depolarizer as a possible precise sunstone for Viking navigation by polarized skylight
Authors: Ropars Guy , Gorre Gabriel , Le Floch Albert , Enoch Jay , Lakshminarayanan Vasudevan
Published: November 2011

Viking navigation from Norway to America in the northern latitudes remains a mystery for physicists, historians and archaeologists. Polarimetric methods using absorbing dichroic crystals as polarizers to detect a hidden Sun direction using the polarized skylight have led to controversies. Indeed, these techniques may lack in sensitivity, especially when the degree of polarization is low. Here, we demonstrate theoretically and experimentally that using the transparent common Iceland spar as a depolarizer, the Vikings could have performed a precise navigation under different conditions. Indeed, when simply rotated, such a birefringent crystal can completely depolarize, at the so-called isotropy point, any partially polarized state of light, allowing us to guess the direction of the Sun. By equalizing the intensities of the ordinary and extraordinary beams at the isotropy point, we show that the Sun direction can be determined easily, thanks to a simple sensitive differential two-image observation. A precision of a few degrees could be reached even under dark crepuscular conditions. The exciting recent discovery of such an Iceland spar in the Alderney Elizabethan ship that sank two centuries before the introduction of the polarization of light in optics may support the use of the calcite crystal for navigation purposes.
Tissue- and Cell-Type Specific Transcriptome Profiling of Expanding Tomato Fruit Provides Insights into Metabolic and Regulatory Specialization and Cuticle Formation
Authors: Matas Antonio J. , Yeats Trevor H. , Buda Gregory J. , Zheng Yi , Chatterjee Subhasish , Tohge Takayuki , Ponnala Lalit , Adato Avital , Aharoni Asaph , Stark Ruth , Fernie Alisdair R. , Fei Zhangjun , Giovannoni James J. , Rose Jocelyn K.C.
Published: November 2011

Tomato (Solanum lycopersicum) is the primary model for the study of fleshy fruits, and research in this species has elucidated many aspects of fruit physiology, development, and metabolism. However, most of these studies have involved homogenization of the fruit pericarp, with its many constituent cell types. Here, we describe the coupling of pyrosequencing technology with laser capture microdissection to characterize the transcriptomes of the five principal tissues of the pericarp from tomato fruits (outer and inner epidermal layers, collenchyma, parenchyma, and vascular tissues) at their maximal growth phase. A total of 20,976 high-quality expressed unigenes were identified, of which more than half were ubiquitous in their expression, while others were cell type specific or showed distinct expression patterns in specific tissues. The data provide new insights into the spatial distribution of many classes of regulatory and structural genes, including those involved in energy metabolism, source-sink relationships, secondary metabolite production, cell wall biology, and cuticle biogenesis. Finally, patterns of similar gene expression between tissues led to the characterization of a cuticle on the inner surface of the pericarp, demonstrating the utility of this approach as a platform for biological discovery.
Tumor suppressor p16INK4a controls oncogenic K‐Ras function in human pancreatic cancer cells
Authors: Rabien Anja , Sanchez‐Ruderisch Hugo , Schulz Petra , Otto Noreen , Wimmel Anja , Wiedenmann Bertram , Detjen Katharina M.
Published: November 2011

Pancreatic cancer is characterized by oncogenic activation of K‐Ras and inactivation of the cell cycle inhibitor p16INK4a. We previously demonstrated that reintroduction of p16INK4a reversed anoikis resistance and clonogenicity of human pancreatic cancer cells, properties commonly attributed to the transforming potential of oncogenic K‐Ras. Therefore, we aimed to determine the role of Ras after p16INK4a re‐expression. Here, we show that restitution of p16INK4a in pancreatic cancer cell lines elicits a profound suppression of K‐Ras activity. A more detailed analysis in p16INK4a reconstituted Capan‐1 cells indicated selective reduction of both K‐Ras activity and protein stability. Re‐expression of K‐Ras in p16INK4a restituted Capan‐1 cells reversed the anoikis‐sensitive phenotype and increased colony formation, indicating that K‐Ras suppression was required for p16INK4a‐mediated reversion of the transformed phenotype. Inducible expression of p16INK4a in DanG cells confirmed inhibition of K‐Ras activity as well as an increase in anoikis susceptibility. Thus, our results delineate a novel functional interaction with defined biological consequences for the two most frequent alterations observed in pancreatic cancer. (Cancer Sci 2012; 103: 169–175)
Comparison of intranasal methamphetamine and d‐amphetamine self‐administration by humans
Authors: Kirkpatrick Matthew G. , Gunderson Erik W. , Johanson Chris‐Ellyn , Levin Frances R. , Foltin Richard W. , Hart Carl L.
Published: November 2011

Aims  There are no studies directly comparing self‐administration of methamphetamine and d‐amphetamine by humans. This study compared intranasal methamphetamine‐ and d‐amphetamine self‐administration and characterized the mood, performance and physiological effects produced by the drugs.

Design  A randomized, double‐blind, placebo‐controlled, cross‐over study.

Setting  An out‐patient research unit at the New York State Psychiatric Institute.

Participants  Male recreational methamphetamine users (n = 13).

Measurements  Five 2‐day blocks of sessions were conducted. On the first day of each block, participants ‘sampled’ a single methamphetamine or d‐amphetamine dose (0, 12, 50 mg/70 kg) and a monetary reinforcer ($5 or $20). Amphetamine plasma levels, cardiovascular, mood, and psychomotor performance effects were assessed before drug administration and repeatedly thereafter. On the second day of each block, participants chose between the sampled reinforcers (drug or money).

Findings  There were no significant differences between the drugs on the majority of measures. Under the $5 condition, both amphetamines increased self‐administration dose‐dependently, with 41% drug choices overall. Under the $20 condition, only 17% drug options were selected. Both drugs increased cardiovascular activity and ‘positive’ mood, although methamphetamine produced more prominent effects on some measures (e.g. heart rate and ratings of ‘high’).

Conclusions  Methamphetamine and d‐amphetamines appear to produce a similar dose‐related profile of effects in humans, which supports their equivalence for abuse potential.
Incidence and implications of negative serum thyroglobulin but positive I‐131 whole‐body scans in patients with well‐differentiated thyroid cancer prepared with rhTSH or thyroid hormone withdrawal
Authors: Cherk Martin H. , Francis Peter , Topliss Duncan J. , Bailey Michael , Kalff Victor
Published: November 2011

Aims  To evaluate the incidence and clinical implications of a positive whole‐body I‐131 scan but negative stimulated serum Tg/TgAb level following an ablative or diagnostic I‐131 dose in patients with well‐differentiated thyroid cancer and whether there is a difference in incidence if prepared with thyroid hormone withdrawal compared with rhTSH stimulation.

Methods  I‐131 scan findings, serum Tg/TgAb levels, TNM stage and method of thyroid tissue stimulation in 193 consecutive patients (138F, 55M) with well‐differentiated thyroid cancer undergoing postoperative ablative I‐131 therapy and 121 consecutive (94F, 27M) patients undergoing diagnostic I‐131 surveillance scans were retrospectively reviewed. Comparisons of proportions were performed using Chi‐square tests. Clinical, biochemical and I‐131 scan follow‐up data were obtained for each patient cohort.

Results  39/193 (20·2%) postablative I‐131 and 10/121 (8·3%) diagnostic I‐131 patients had negative stimulated serum Tg/TgAb levels but positive I‐131 scans for residual thyroid tissue. Nine (4·7%) of the postablative patients had I‐131 uptake in the lateral neck suspicious for loco‐regional metastatic disease. In the postablative I‐131 group, 38/169 (22·5%) prepared with rhTSH compared to 1/24 (4·2%) prepared with thyroid hormone withdrawal were Tg/TgAb negative but I‐131 scan positive (P = 0·04). Follow‐up of 21/39 postablative I‐131 patients with negative Tg/TgAb but positive I‐131 scans confirmed a significant proportion of patients (4/21) (19·1%), remained Tg/TgAb negative/I‐131 scan positive, some of whom had higher‐risk disease at original diagnosis (2/4) (50%).

Conclusions  Our study confirms that in the setting of I‐131 ablation therapy or diagnostic I‐131 scanning, a significant proportion of patients (20·2% and 8·3%, respectively) have residual benign or malignant thyroid tissue on whole‐body scanning despite a negative stimulated serum Tg level. Whether such patients who would otherwise be missed as having residual thyroid tissue on serum Tg testing alone have a worse clinical outcome remains uncertain. Our findings do however suggest performing both stimulated serum Tg/TgAb levels and I‐131 scans for the follow‐up of patients with higher‐risk thyroid cancer may be important. There may also be a slightly higher incidence of this phenomenon in patients prepared with rhTSH rather than by thyroxine withdrawal.
Diagnosis and therapy for Cushing’s disease with negative dynamic MRI finding: a single‐centre experience
Authors: Sun Yuhao , Sun Qingfang , Fan Changyan , Shen Jiankang , Zhao Weiguo , Guo Yan , Su Tingwei , Wang Weiqing , Ning Guang , Bian Liuguan
Published: November 2011

Objective  Most patients with Cushing’s disease (CD) will have evidence of an adenoma on high‐resolution magnetic resonance imaging (MRI). However, a significant minority of patients with CD and biochemical hypercortisolaemia have no visible adenoma on MRI. The purpose of this study was to evaluate the diagnostic value of preoperative biochemical assessment and accuracy of MRI findings on surgical outcome.

Design  Retrospective data set analyses.

Patients and measurement  The clinical, endocrinological, histopathological and surgical outcomes of 24 consecutive CD patients with negative MRI findings were compared with those of 95 consecutive age‐ and sex‐matched CD patients with pituitary adenomas on MRI.

Results  The total remission rate was 86·6%. Among all patients, 87 had concordant positive endocrine tests and underwent neurosurgery, while bilateral inferior petrosal sinus sampling (BIPSS) was performed in 12 and 50 other patients with negative and positive MRI, respectively. A pituitary adenoma, confirmed by pathological examination, was found in 83·3% and 93·6% of patients with negative and positive MRI, respectively. The remission rate was not different between patients with negative and positive MRI (87·5 % and 86·3%, respectively; P > 0·05) or between patients who did not undergo BIPSS with negative MRI and patients with positive MRI (P > 0·05). The remission rate of patients who underwent BIPSS with negative MRI was not different from those not undergoing BIPSS (P > 0·05). The recurrence rate was higher, although not statistically different, in patients with negative MRI compared to positive ones.

Conclusions  Based on the findings outlined, MRI‐negative CD may be a surgically remediable syndrome, with a pathophysiological basis that primarily involves a pituitary cause of the hypercortisolaemia.
Healthcare resource utilization among haemophilia A patients in the United States
Authors: VALENTINO L. A. , PIPE S. W. , TARANTINO M. D. , YE X. , XIONG Y. , LUO M. P.
Published: November 2011

Summary.  Advances in therapy have improved life expectancy and quality of life of patients with haemophilia A. Due to the chronic and complex management of this disease, particularly, the development of inhibitors, little is known about their health resource utilization in the real‐life setting over time. The aim was to assess the distribution and trend of healthcare resource utilization among US haemophilia A patients with and without inhibitors. The MarketScan® Database, was queried to identify individuals with ≥1 year continuous enrolment, two medical diagnoses of haemophilia A and claims for factor VIII or bypassing agent (to infer inhibitor status) during 2001–2007. Haemophilia‐related cost was estimated from inpatient, outpatient and pharmacy claims. Annual cost differences were assessed by age and over a 4‐year period for those with continuous enrolment. Among 51 million covered lives, 1044 haemophilia patients were identified, of whom 981 (94%; mean age = 21.2 years) did not have an inhibitor. The median haemophilia‐related cost for these patients was $63,935 per patient per year. When normalized by weight, annual cost was stable (no statistically significant differences) among 312 non‐inhibitor patients (mean age = 21.8 years) with 4‐year continuous data. While there was a wide distribution of haemophilia‐related cost among the 63 individuals with an inhibitor (mean age = 15.4 years), only 0.6% of the total haemophilia patients had costs exceeding $1 million per patient per year. This study indicated that most haemophilia A patients were inhibitor‐free with relatively stable annual costs over time. There was a wide distribution of haemophilia‐related cost for inhibitor patients, while the proportion of patients who incurred extreme high cost was low.
Immunoprotective effect of von Willebrand factor towards therapeutic factor VIII in experimental haemophilia A
Authors: DELIGNAT S. , REPESSÉ Y. , NAVARRETE A. ‐M. , MESLIER Y. , GUPTA N. , CHRISTOPHE O. D. , KAVERI S. V. , LACROIX‐DESMAZES S.
Published: November 2011

Summary.  The development of inhibitory anti‐factor VIII (FVIII) antibodies in patients with haemophilia A following replacement therapy is associated with several types of risk factors. Among these, the purity of FVIII concentrates, and in particular the presence of von Willebrand factor (VWF), was controversially proposed to influence the immunogenicity of exogenous FVIII. We re‐assessed in vivo and in vitro the immuno‐protective effect of VWF towards FVIII. The immuno‐protective effect of VWF towards FVIII was investigated in vivo, in a model of haemophilia A. We studied the endocytosis of FVIII by murine bone marrow‐derived dendritic cells and evaluated the capacity of VWF to block the internalization of FVIII. We characterized the relevance of VWF for the accumulation of FVIII in the marginal zone of the spleen, a secondary lymphoid organ where the immune response to therapeutically administered FVIII initiates. Our results confirm that VWF reduces the immunogenicity of FVIII in FVIII‐deficient mice. Paradoxically, VWF is important for the accumulation of FVIII in the marginal zone of the spleen. We propose that VWF exerts at least two non‐mutually exclusive immunoprotective roles towards FVIII in haemophilic mice: VWF prevents the endocytosis of FVIII by professional antigen‐presenting cells by blocking the interaction of FVIII with as yet unidentified endocytic receptor(s). Hypothetically, VWF, by virtue of increasing the half‐life of FVIII in the circulation, may allow an increased contact time with tolerogenic marginal zone B cells in the spleen.