bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic relationships and genotype tracing in date palms (Phoenix dactylifera L.) in Oman, based on microsatellite markers
Authors: Al-Ruqaishi Ishaq Ahmed , Davey Michael , Alderson Peter , Mayes Sean
Published: March 2008

Microsatellite markers (SSRs) were used to screen and analyse the genetic diversity among clonal genotypes of date palm (Phoenix dactylifera L.) derived by somatic embryogenesis in Oman. Twenty-one palms, representing 14 Omani, five Bahraini, one Iraqi and one Moroccan genotype, were screened with ten microsatellite markers. All primer pairs produced an amplification product in the expected size range and detected high levels of polymorphism among the analysed samples. Correspondence analysis revealed that the genotypes from Bahrain and Iraq showed a close relationship with accessions already grown in Oman. The genotype from Morocco (Medjool) appeared distinct from the rest of the material. Three independent clonal lines derived from a single Khalas Aldahra genotype were found to give identical genetic fingerprints. The value of this work for date palm production and conservation in Oman is discussed.
Satellite‐based measurements of gravity wave‐induced midlatitude plasma density perturbations
Authors: Earle G. D. , Musumba A. M. , Vadas Sharon L.
Published: March 2008

Large amplitude anticorrelated wave structures appear at midlatitudes in the nighttime ionospheric plasma and neutral density measurements made at altitudes between 250 and 300 km by the Dynamics Explorer‐2 satellite. The wavelengths along the satellite orbit track are generally longer than a hundred kilometers, and the vertical perturbation velocities are about 20 m/s. These characteristics are consistent with plasma motions driven by gravity waves in the neutral atmosphere as they propagate upward from lower atmospheric source regions. The altitude and the horizontal wavelengths observed provide in situ empirical validation of a recently developed gravity wave propagation model that includes the effects of both kinematic viscosity and thermal diffusivity at high altitudes.
Sodium/hydrogen exchange inhibition with cariporide reduces leukocyte adhesion via P‐selectin suppression during inflammation
Authors: Buerke U , Pruefer D , Carter J M , Russ M , Schlitt A , Prondzinsky R , Makowski J , Rohrbach S , Niemann B , Schulze C , Dahm M , Vahl C‐F , Werdan K , Buerke M
Published: March 2008

Background and purpose:

The Na+/H+ exchange (NHE) inhibitor cariporide is known to ameliorate ischaemia/reperfusion (I/R) injury by reduction of cytosolic Ca2+ overload. Leukocyte activation and infiltration also mediates I/R injury but whether cariporide reduces I/R injury by affecting leukocyte activation is unknown. We studied the effect of cariporide on thrombin and I/R induced leukocyte activation and infiltration models and examined P‐selectin expression as a potential mechanism for any identified effects.

Experimental approach:

An in vivo rat mesenteric microcirculation microscopy model was used with stimulation by thrombin (0.5 μ ml−1) superfusion or ischaemia (by haemorrhagic shock for 60 min) and reperfusion (90 min).

Key results:

Treatment with cariporide (10 mg kg−1 i.v.) significantly reduced leukocyte rolling, adhesion and extravasation after thrombin exposure. Similarly, cariporide reduced leukocyte rolling (54±6.2 to 2.4±1.0 cells min−1, P<0.01), adherence (6.3±1.9 to 1.2±0.4 cells 100 μm−1, P<0.01) and extravasation (9.1±2.1 to 2.4±1.1 cells per 20 × 100 μm perivascular space, P<0.05), following haemorrhagic shock induced systemic ischaemia and reperfusion. The cell adhesion molecule P‐selectin showed a profound decrease in endothelial expression following cariporide administration in both thrombin and I/R stimulated groups (35.4±3.2 vs 14.2±4.1% P‐selectin positive cells per tissue section, P<0.01).

Conclusions and implications:

The NHE inhibitor cariporide is known to limit reperfusion injury by controlling Ca2+ overload but these data are novel evidence for a vasculoprotective effect of NHE inhibition at all levels of leukocyte activation, an effect which is likely to be mediated at least in part by a reduction of P‐selectin expression.

British Journal of Pharmacology (2008) 153, 1678–1685; doi:10.1038/sj.bjp.0707647; published online 10 March 2008
Unravelling the Dynamics of IOIS Implementation: An Actor-Network Study of an IOIS in the Seaport of Barcelona
Authors: Rodon Juan , Pastor Joan Antoni , Sesé Feliciano , Christiaanse Ellen
Published: March 2008

Although inter-organizational information systems (IOIS) implementation has been widely studied, mainstream literature has not focused on understanding how implementation unfolds and how the existing components of the installed base shape the process. This paper addresses this gap by conducting a socio-technical, process-oriented, and multilevel study. Based on a longitudinal in-depth case study of the implementation of an industry IOIS, we develop an explication of IOIS implementation that considers the role of the installed base. Using the lens of actor-network theory (ANT), we counter the mainstream IOIS literature by showing that IOIS implementation cannot only be explained by a fixed set of independent factors; instead, the dynamic mutual shaping of socio-technical actors throughout implementation complements existing factor-based models in explaining the evolution and the outcome (success or failure). The study also shows the importance of complying with the technical and non-technical components of the installed base for an IOIS to be successfully initiated.
Pattern dependency in selective epitaxy of B-doped SiGe layers for advanced metal oxide semiconductor field effect transistors
Authors: Hållstedt J. , Kolahdouz M. , Ghandi R. , Radamson H. H. , Wise R.
Published: March 2008

This study presents investigations about the physical mechanisms, origin, and methods to control the pattern dependency in selective epitaxial growth of Si1−xGex (x=0.14–0.32) layers. It is shown with a comprehensive experimental study that the local Si coverage of individual chips on patterned wafers is the main parameter for the layer profile in the epitaxial growth. This was explained by the gas depletion of the growth species in the low velocity boundary layer over the wafer. The gas depletion radius around each oxide opening was in the centimeter range which is related to the boundary layer thickness. The results from these experiments were applied to grow Si0.75Ge0.25 layers with B concentration of 4×1020cm−3 selectively for elevated source and drains in fully depleted ultrathin body silicon on insulator p metal oxide semiconductor field effect transistor (p-MOSFET) devices. The epitaxy control was maintained over a wide range of device sizes by optimized process parameters in combination with a wafer pattern design consisting of dummy features causing a uniform gas depletion over the chips on the wafer.
Field detection in single and double barrier MgO magnetic tunnel junction sensors
Authors: Almeida J. M. , Wisniowski P. , Freitas P. P.
Published: March 2008

Single and double barrier MgO based magnetic tunnel junction sensors were processed with area of 200μm2 and small aspect ratios (<2). These sensors present resistance area products ranging from 10to70kΩμm2 and tunneling magnetoresistance (TMR) values of up to 160%. Sensor linearization was mostly obtained by thinning the CoFeB free layer to 15.5A, close to the free layer transition from ferromagnetic to superparamagnetic behavior. Three different thicknesses were studied for the free layer CoFeB: 1.55, 1.8, and 3nm. The CoFeB thickness decrease required for the linearization implies a loss in TMR. Field detection range of ∼80pT∕Hz0.5 was obtained for both double and single barrier sensors (at 500KHz). Out of the 1∕f regime, the detection range decreases to ∼2pT∕Hz0.5 for the single barrier sensor. The field detection dependence on bias voltage was also studied at 500KHz and outside the 1∕f dominated regime.
Detection of the weak magnetic properties change of stainless-steel welding parts by low frequency magnetic imaging
Authors: Hayashi Takayuki , Yamada Hironobu , Kiwa Toshihiko , Tsukada Keiji , Tamazumi Masaji
Published: March 2008

Differences in weld quality resulting from variations in welding conditions were detected via low frequency magnetic imaging. This magnetic imaging was obtained using a recently developed measurement system, consisting of an exposure coil, a magnetoresistive (MR) sensor, and a lock-in amplifier. A wide area of stainless-steel sample was exposed to the magnetic field via an induction coil, and the MR sensor measured the generated magnetic field from the sample. The frequency of the magnetic field ranged from 20Hzto1kHz. A cylindrical stainless-steel sample was fabricated by rolling a stainless-steel sheet and welding each edge by an arc welder with argon gas, while the welding condition was changed by controlling the argon gas flow. The magnitude and phase shift of the generated magnetic field from the sample was measured by scanning the MR sensor on the sample surface. The change in magnetic properties caused by the welding condition change was successfully imaged.
Hybrid magnetoresistive∕microelectromechanical devices for static field modulation and sensor 1∕f noise cancellation
Authors: Guedes A. , Patil S. B. , Cardoso S. , Chu V. , Conde J. P. , Freitas P. P.
Published: March 2008

Low frequency 1∕f noise in magnetoresistive (MR) spin valve sensors was suppressed by modulating an external dc magnetic field at high frequency microelectromechanical system using a (MEMS) microcantilever structure with an integrated magnetic flux guide. With this hybrid MR∕MEMS device, direct detection of dc magnetic fields in the sensor high frequency thermal noise regime was achieved. The microcantilever was actuated using a gate electrode by applying an ac voltage with frequency f, causing it to oscillate at 2f. Measurements show detection of a dc magnetic field at 2f frequency (400kHz), where sensor 1∕f noise is two orders of magnitude lower than dc.
Hydrogenated amorphous silicon a-Si:Hx∕a-Si:Hy compositional superlattices: Profiling the lattice-constant-scale spatial change of the designed Si–H bonding configurations
Authors: Jiang Yeu-Long , Shih Pei-Tzong , Kuo Tai-Chao
Published: March 2008

Hydrogenated amorphous silicon a-Si:Hx∕a-Si:Hy compositional superlattices are produced by periodic switching two pulse-wave modulation plasmas. Simply varying the on and off times of pulse waves selectively controls the Si–H bonding configurations and yields a-Si:Hx∕a-Si:Hy superlattices with spatial periodic change of the designed monohydride (SiH) bonds and polyhydride (SiH2)n bonds over ultrathin periods (4.5–2.5nm) with lattice-constant sublayer thicknesses (2.5–0.75nm). The superlattice structures are identified by the observation of x-ray Bragg’s diffraction peaks. The bandgap and refractive index are controlled by the spatial distribution of different Si–H bonds and changing sublayer thickness in superlattice structure.
Regular approximations to chaotic maps
Authors: Korneev N.
Published: March 2008

We construct regular analytic approximations to partly chaotic maps on a two-dimensional torus—the Standard Map in particular. Possible extensions are discussed.
Bond connectivity measured via relaxation-assisted two-dimensional infrared spectroscopy
Authors: Naraharisetty Sri Ram G. , Kasyanenko Valeriy M. , Rubtsov Igor V.
Published: March 2008

The relaxation-assisted two-dimensional infrared (RA 2DIR) method is a novel technique for probing structures of molecules, which relies on vibrational energy transport in molecules. In this article we demonstrate the ability of RA 2DIR to detect the bond connectivity patterns in molecules using two parameters, a characteristic intermode energy transport time (arrival time) and a cross-peak amplification coefficient. A correlation of the arrival time with the distance between the modes is demonstrated. An 18-fold amplification of the cross-peak amplitude for the modes separated by ∼11Å is shown using RA 2DIR; larger cross-peak amplifications are expected for the modes separated by larger distances. The RA 2DIR method enhances the applicability of 2DIR spectroscopy by making practical the long-range measurements using a variety of structural reporters, including weak IR modes. The data presented demonstrate the analytical power of RA 2DIR which permits the speedy structural assessments of the bond connectivity patterns.
A study of time correlations in lattice Boltzmann-based large-eddy simulation of isotropic turbulence
Authors: Dong Yu-Hong , Sagaut Pierre
Published: March 2008

As one of statistical characteristics of turbulent flow, space-time correlation is important when studies contribute to understanding of the mechanism of sound radiation and wave scattering by turbulence. This paper combines large-eddy simulations (LES) with the lattice Boltzmann method (LBM) to study the effects of subgrid models on time correlations in decaying isotropic turbulence. The performance of the inertial-range (IR) consistent model and the classical Smagorinsky model is evaluated in terms of two-time Eulerian velocity correlations at the LBM framework. The present study compares the correlations evaluated by LES and the direct numerical simulations based on the lattice Boltzmann equation and Navier–Stokes (NS) equations, respectively. It shows that the lattice Boltzmann subgrid models yield an underestimation of the magnitude of the time correlation on different time intervals and on a variety of wavenumber modes, similar to NS subgrid models. It is also observed that the calculated decorrelation time scale is in good agreement with the theoretical analysis for the Eulerian time microscale and scales nearly as τ(k)∝(Vk)−1. It appears that τ(k) may be either underestimated or overestimated depending on the shape of initial energy spectrum to some extent. Furthermore, compared to the classical Smagorinsky model with different initial spectra, the IR consistent subgrid model shows promising performance on the prediction of the time-space correlations in turbulent flows.
Ferroelectric nanoparticles in low refractive index liquid crystals for strong electro-optic response
Authors: Kaczmarek M. , Buchnev O. , Nandhakumar I.
Published: March 2008

Functional materials based on ferroelectric, inorganic nanoparticles, and low refractive index nematic liquid crystals show strong induced birefringence and dielectric anisotropy. Birefringence can increase by a factor of 2 and dielectric anisotropy by a factor of 3 as compared with nominally pure liquid crystals. The enhancement of the electro-optic performance is higher in liquid crystals with Sn2P2S6 (SPS) nanoparticles than with BaTiO3 nanoparticles. The shape and size distribution of both types of ferroelectric particles were characterized using atomic force microscopy. The average size of SPS nanoparticles was 45nm and of BaTiO3 nanoparticles was 20nm.
Conformal mapping analysis of multipactor breakdown in waveguide irises
Authors: Semenov V. E. , Rakova E. , Udiljak R. , Anderson D. , Lisak M. , Puech J.
Published: March 2008

Multipactor breakdown in a single waveguide iris is analyzed using the quasistatic approximation for the spatial distribution of the rf field in the iris. Based on the conformal mapping approach, an analytical description is given of the rf field structure in the iris. It is shown that in the central part of any iris with a length to height ratio greater than approximately 0.5, the rf field structure is close to that between two parallel plates. The multipactor threshold for the iris is determined mainly by electron losses from the central part of the iris where the losses are due to the tangential component of the emission velocity of secondary electrons. The effective length of the iris central part is determined and an estimate of the multipactor threshold for the iris is found in terms of the conventional parameters: Applied rf voltage, product of rf frequency and iris height, and iris length to height ratio. Numerical simulations are also carried out using the exact analytical description of the quasistatic rf field and taking into account a spread of electron emission velocities.
Ni
∕
Al
0.2
Ga
0.8
N
interfacial reaction and Schottky contact formation using high quality epitaxial layers
Authors: Boudjelida B. , Gee I. , Evans-Freeman J. , Clark S. A. , Maffeis T. G. G. , Teng K. S. , Wilks S. , Azize M. , Bethoux J.-M. , De Mierry P.
Published: March 2008

The formation of the Ni∕Al0.2Ga0.8N Schottky contacts has been investigated by x-ray photoelectron spectroscopy. In situ scanning tunneling microscopy was used in parallel to investigate the morphology of the Ni covered surface after the last deposition. In the same way, results are presented through two perspectives: the intensity of core-level signals which give information on the growth mode, and the core-level binding energy positions which assess changes in electronic and chemical properties as a function of Ni coverage. Ni deposition on Al0.2Ga0.8N substrates follows the Stranski–Krastanov growth mode. It is suggested that Ni preferably reacts with the contaminants at the surface rather than with the epilayer itself. The Schottky barrier formation is discussed in terms of unified defect and metal-induced gap states models.
Inertial range turbulence in kinetic plasmas
Authors: Howes Gregory G.
Published: March 2008

The transfer of turbulent energy through an inertial range from the driving scale to dissipative scales in a kinetic plasma followed by the conversion of this energy into heat is a fundamental plasma physics process. A theoretical foundation for the study of this process is constructed, but the details of the kinetic cascade are not well understood. Several important properties are identified: (a) The conservation of a generalized energy by the cascade; (b) the need for collisions to increase entropy and realize irreversible plasma heating; and (c) the key role played by the entropy cascade—a dual cascade of energy to small scales in both physical and velocity space—to convert ultimately the turbulent energy into heat. A strategy for nonlinear numerical simulations of kinetic turbulence is outlined. Initial numerical results are consistent with the operation of the entropy cascade. Inertial range turbulence arises in a broad range of space and astrophysical plasmas and may play an important role in the thermalization of fusion energy in burning plasmas.
High performance of GaN thin films grown on sapphire substrates coated with a silica-submicron-sphere monolayer film
Authors: Ueda Kazumasa , Tsuchida Yoshihiko , Hagura Nobuhiro , Iskandar Ferry , Okuyama Kikuo , Endo Yoshiyuki
Published: March 2008

A high-performance, GaN-based light emitting diode (LED) was prepared using a metal organic chemical vapor deposition method on a silica-sphere, monolayer-coated sapphire substrate. Various surface coverage ratios of the silica submicron spheres with diameters ranging from 300to550nm were deposited on the sapphire substrate using a spin-coating method. The LED output power was increased 2.5-fold compared with the LED constructed without silica spheres and uniform light distribution was achieved. In addition, LED output power was dependent on silica-sphere size and surface coverage of the substrates.
Remarkable influence of the number of nanowires on plasmonic behaviors of the coupled metallic nanowire chain
Authors: Chu H. S. , Ewe W. B. , Koh W. S. , Li E. P.
Published: March 2008

We investigate the plasmonic properties in terms of plasmonic resonances, near field intensity, and charge distribution of interacting nanowires chain which consists of small and large numbers of coupled silver nanowires. We show that the dominant resonance wavelength increases monotonically as the number of nanowires increases. On the other hand, the near field intensity is not only dependent on the chain length but also on the plasmonic resonances in the same chain length. The charge distribution is also demonstrated to fully understand the dependence of plasmonic properties on the chain length.
Broadside coupling to long-range surface plasmons using an angle-cleaved optical fiber
Authors: Charbonneau Robert , Lisicka-Shrzek Ewa , Berini Pierre
Published: March 2008

A technique for evanescent broadside coupling to surface plasmons is described and demonstrated. The technique makes use of a polarization maintaining optical fiber cleaved at a steep angle and positioned near the structure to be excited such that the slow mode of the fiber couples evanescently to the surface plasmon propagating thereon. The technique is applied to excite long-range surface plasmons on a metal stripe supported by a freestanding dielectric membrane. The technique should be useful for coupling to other plasmonic or dielectric waveguides, and for optical wafer probing.
Synthesis of gold-silicon core-shell nanoparticles with tunable localized surface plasmon resonance
Authors: Mohapatra S. , Mishra Y. K. , Avasthi D. K. , Kabiraj D. , Ghatak J. , Varma S.
Published: March 2008

Gold-silicon core-shell nanoparticles embedded in silica matrix, evident by transmission electron microscopy and x-ray photoelectron spectroscopy were synthesized by atom beam cosputtering followed by thermal annealing. Optical absorption studies revealed localized surface plasmon resonance (LSPR), which showed regular redshift from 500to583nm with increase in annealing temperature. The observed redshifts in the LSPR peaks are in close agreement with the theoretical calculations assuming Si nanoshells surrounding Au nanoparticles. The Au–Si core-shell formation is explained by Au–Si liquid nanodroplet formation at temperatures higher than the eutectic temperature, followed by phase separation during subsequent cooling.
Stereo-photography of streamers in air
Authors: Nijdam S. , Moerman J. S. , Briels T. M. P. , van Veldhuizen E. M. , Ebert U.
Published: March 2008

Standard photographs of streamer discharges show a two-dimensional projection. Here, we present stereophotographic images that resolve their three-dimensional structure. We describe the stereoscopic setup and evaluation, and we present results for positive streamer discharges in air at 0.2–1bar in a point-plane geometry with a gap distance of 14cm and a voltage pulse of 47kV. In this case, an approximately Gaussian distribution of branching angles of 43°±12° is found; these angles do not significantly depend on the distance from the needle or on the gas pressure.
State-independent optimal control of dissipative qubits
Authors: Wenin M. , Pötz W.
Published: March 2008

A general state-independent optimal control strategy for weakly dissipative quantum systems is presented. It allows the identification of Hamilton operators which approximately perform a preselected unitary operation and minimize the adverse effects from a dissipative environment. This direct method is demonstrated at the example of a single qubit, as realized, for example, by the spin of an excess electron in a quantum dot or a Josephson flux qubit, with Lindblad dissipator. We show that optimal solutions for arbitrary unitary single-qubit operations may be found both analytically and numerically.
Spatial dynamics of the light emission from a microplasma array
Authors: Waskoenig J. , O’Connell D. , Schulz- von der Gathen V. , Winter J. , Park S.-J. , Eden J. G.
Published: March 2008

The spatial dynamics of the optical emission from an array of 50×50 individual microplasma devices is reported. The array is operated in noble gas at atmospheric pressure with an ac voltage. The optical emission is analyzed with phase and space resolution. It has been found that the emission is not continuous over the entire ac period, it occurs only twice in each cycle. Each of the observed emission phases shows a self-pulsing of the discharge, with several bursts of emission of a fixed width and repetition rate. Cross-talk between the individual devices can be observed through spatially resolved measurements.
Diffusion of nickel and tin in p-type (Bi,Sb)2Te3 and n-type Bi2(Te,Se)3 thermoelectric materials
Authors: Lan Y. C. , Wang D. Z. , Chen G. , Ren Z. F.
Published: March 2008

The diffusion and spatial distribution of tin from solder, and nickel from diffusion barrier in p-type (Bi,Sb)2Te3 and n-type Bi2(Te,Se)3 thermoelectric materials were investigated using electron microscopy. The results indicate that nickel is a suitable diffusion-barrier material for tin in both (Bi,Sb)2Te3 and Bi2(Te,Se)3. However, even though it is not an issue in the (Bi,Sb)2Te3, the nickel diffuses several microns into the Bi2(Te,Se)3 during the soldering processing and degrades its performance. Diffusion coefficients of nickel in p-type (Bi,Sb)2Te3 and in n-type Bi2(Te,Se)3 were also quantitatively studied.
Studies of competition between Nassella trichotoma (Nees) Hack. ex Arechav. (serrated tussock) and native pastures. 1. Adult plants
Authors: Badgery W. B. , Kemp D. R. , Michalk D. L. , King W. McG.
Published: March 2008

Nassella trichotoma (serrated tussock) is a hardy perennial grass weed that rapidly invades disturbed areas. Pasture competition is an important component of an integrated weed-management system for native pastures. This paper reports on a field experiment to ascertain the level of competition from native grasses for adult N. trichotoma plants. Native grasses prevented N. trichotoma plants from increasing in biomass and basal area when rotationally grazed or when grazing was removed and fertiliser was withheld. Smaller N. trichotoma plants (<500 mm2) were more likely to vary in size with very little change in larger plants. Flupropanate efficiently killed all N. trichotoma plants but caused considerable damage to perennial native species, resulting in an uncompetitive pasture dominated by broadleaf weeds.
Genotyping elite genotypes within the Australian lentil breeding program with lentil-specific sequenced tagged microsatellite site (STMS) markers
Authors: Inder P. , Materne M. , Taylor P. W. J. , Ford R.
Published: March 2008

Lentil (Lens culinaris ssp. culinaris) is consumed in many countries as a rich source of protein in largely vegetarian diets. Australia grows lentil as a cash crop in rotation with cereal and produces predominantly red lentils that are exported throughout the world, particularly to countries in South Asia and the Middle East. Differentiation of varieties is important when exporting products to such markets, maintaining variety purity during seed production and in the collection of end-point royalties. Lentil-specific and fluorescent sequenced tagged microsatellite markers (STMS) markers were used to construct a DNA fingerprint database for 10 Lens culinaris ssp. culinaris genotypes (Northfield, Digger, ILL7537, Nugget, Indianhead, ILL2024, ILL6788, Palouse, Nipper and Boomer) that represent major new cultivars and key breeding lines within the Australian breeding program. All 10 lentil genotypes were distinguished using the assessed STMS loci. Unique alleles were observed for several lines, including Boomer and Nipper, varieties recently released in Australia. This database will play an important role in seed typing for commercial export certification and the commercial management of cultivars.
Detection and characterisation of novel fungal endophyte genotypic variation in cultivars of perennial ryegrass (Lolium perenne L.)
Authors: van Zijll de Jong E. , Dobrowolski M. P. , Sandford A. , Smith K. F. , Willocks M. J. , Spangenberg G. C. , Forster J. W.
Published: March 2008

Alkaloids produced by the perennial ryegrass pasture and turf grass endophyte Neotyphodium lolii confer both beneficial (insect feeding deterrence) and deleterious (mammalian herbivore toxicoses) effects. Novel endophyte strains with altered and desirable in planta metabolic profiles have been introduced into cultivars by inoculation. The potentially severe effects of contamination with standard toxic endophytes provide an important incentive for quality control during varietal development. Genotyping with expressed sequence tag (EST)-derived simple sequence repeat (SSR) markers in order to monitor endophyte content was evaluated in this study. The NEA2 endophyte, described as producing low levels of lolitrem B and moderate quantities of ergovaline and peramine, has been deployed in the cultivar (cv.) Tolosa and transferred to other proprietary varieties by crossing or controlled inoculation. In planta genotypic analysis of cv. Tolosa-derived plants revealed the presence of 2 distinct NEA2 genotypes (A and B). Variable proportions of NEA2 A and B were observed at different stages of cultivar multiplication, and NEA2 B was present in inoculated varieties. Several accessions also revealed the presence of a third genotype (C), identical to standard toxic types. Alkaloid measurement in plants containing individual A and B endophytes identified distinct profiles which collectively account for the average NEA2 profile. The C variant is apparently a contaminant arising from seed or adventitious seedlings during varietal multiplication or incomplete removal of endophyte from seed before inoculation. SSR-based genotyping provides an efficient means to continuously assess endophyte prevalence and identity in pasture grass breeding programs.
Corn-based ethanol production compromises goal of reducing nitrogen export by the Mississippi River
Authors: Donner Simon D. , Kucharik Christopher J.
Published: March 2008

Corn cultivation in the United States is expected to increase to meet demand for ethanol. Nitrogen leaching from fertilized corn fields to the Mississippi–Atchafalaya River system is a primary cause of the bottom-water hypoxia that develops on the continental shelf of the northern Gulf of Mexico each summer. In this study, we combine agricultural land use scenarios with physically based models of terrestrial and aquatic nitrogen to examine the effect of present and future expansion of corn-based ethanol production on nitrogen export by the Mississippi and Atchafalaya Rivers to the Gulf of Mexico. The results show that the increase in corn cultivation required to meet the goal of 15–36 billion gallons of renewable fuels by the year 2022 suggested by a recent U.S. Senate energy policy would increase the annual average flux of dissolved inorganic nitrogen (DIN) export by the Mississippi and Atchafalaya Rivers by 10–34%. Generating 15 billion gallons of corn-based ethanol by the year 2022 will increase the odds that annual DIN export exceeds the target set for reducing hypoxia in the Gulf of Mexico to >95%. Examination of extreme mitigation options shows that expanding corn-based ethanol production would make the already difficult challenges of reducing nitrogen export to the Gulf of Mexico and the extent of hypoxia practically impossible without large shifts in food production and agricultural management.
Acute Treatment Response and Its Predictors in Patients With First-Episode Psychosis in Iran
Authors: Tabatabaee Maryam , Sharifi Vandad , Alaghband-rad Javad , Amini Homayoun , Boroumand Mehran , Omid Abbas , Seddigh Arshia
Published: March 2008

Objective: The aim of this paper was to investigate the acute treatment response and its predictors in a sample of patients with first-episode psychosis admitted to a psychiatric hospital in Iran.

Method: A total of 163 patients with first-episode psychosis were treated with antipsychotics and other medications as prescribed by their treating psychiatrists. Sociodemographic and premorbid data at baseline and clinical data at both baseline and discharge (6±1 weeks after admission) were collected.

Results: Patients showed a response rate of 71.4% for negative symptoms, 91.5% for positive symptoms and 67.5% for functioning. Those having a positive family history and less severe negative symptoms at baseline were less likely to respond in terms of negative symptoms. Higher premorbid and lower baseline functioning as well as acute onset were associated with the treatment response.

Conclusions: Acute treatment response of first-episode psychosis in a clinical sample of a developing country seems to be higher than that of developed countries. However, predictors of response are comparable.
First-Episode Psychosis in Rural, Coastal and Remote Australian Communities
Authors: Stain Helen , Sartore Gina-Maree , Andrews Doug , Kelly Brian
Published: March 2008

Objective: The aim of this study was to investigate access to care and service delivery for first-episode psychosis (FEP) in rural, coastal and remote regions.

Method: Routine clinical outcome data were analysed for patients aged 10–25 years who presented to mental health services in either a rural, coastal or remote region of New South Wales over a 3-year period.

Results: The results showed rural region FEP patients travelled significantly further to access services than non-FEP patients. Remote region FEP patients were older and more likely to be male and Aboriginal than non-FEP patients. Alcohol and drug problems were significantly more likely for FEP than non-FEP patients across all regions. Utilization of mental health services was more frequent for FEP than non-FEP children and adolescents.

Conclusion: The study highlights the importance of identification of FEP, particularly in the 10–18-year age group, where cognitive problems are likely to adversely affect schooling as well as be detrimental to social relationships. Service provision for FEP youth in rural areas requires innovation and coordination of limited resources, including better provision of training and ongoing clinical supervision.
Stability and Fitness of Anilinopyrimidine-Resistant Strains of Botrytis cinerea
Authors: Bardas G. A. , Myresiotis C. K. , Karaoglanidis G. S.
Published: March 2008

The fitness of anilinopyrimidine-resistant isolates of Botrytis cinerea compared with that of sensitive isolates, collected from vegetable crops in Greece during 2005, was investigated. Stability of resistance to anilinopyrimidine fungicides was determined after consecutive transfers of the fungal isolates on fungicide-free potato dextrose agar for 16 culture cycles or on fungicide-untreated cucumber seedlings for eight disease cycles. Results showed that after the consecutive transfers of the isolates either in vitro or in vivo sensitivity to cyprodinil was not changed significantly compared to the initial sensitivity in all the isolates tested, suggesting a stable genetically controlled trait. Fitness parameters measured were mycelial growth, spore production in vitro, osmotic sensitivity, virulence, spore production in vivo, percentage of spore germination, and competitive ability of the resistant isolates in four pairs with sensitive isolates both on artificial nutrient medium or on cucumber seedling plants. The measurements of the fitness components in individual isolates showed high variability within both sensitivity groups in all, except virulence, fitness components tested. As a group, resistant isolates showed significantly lower (P < 0.05) mycelial growth and virulence, while they were more osmotically sensitive than the sensitive isolates. In addition the resistant isolates showed higher (P < 0.05) spore production in vivo but there was no difference (P > 0.05) between the two sensitivity groups in spore production in vitro and in the percentage of spore germination. However, the correlation to test if there is any relationship between the values of each fitness component tested and the level of cyprodinil sensitivity of each isolate was for all, except the spore production in vivo, fitness components not significant (P > 0.05). This absence of significant correlation coefficient values suggests that the development of resistance to anilinopyrimidine fungicides did not affect the fitness of the resistant isolates. Competition of the resistant versus sensitive isolates was isolates-dependent, since in two of the isolate pairs the resistance frequency decreased significantly after five culture or disease cycles, while in the remaining two pairs resistance frequency increased significantly after five disease cycles or remained stable for one pair after five culture cycles on artificial nutrient media.
Systemic Disease Protection Elicited by Plant Growth Promoting Rhizobacteria Strains: Relationship Between Metabolic Responses, Systemic Disease Protection, and Biotic Elicitors
Authors: Ramos Solano B. , Barriuso Maicas J. , Pereyra de la Iglesia M. T. , Domenech J. , Gutiérrez Mañero F. J.
Published: March 2008

A study of plant defensive systemic responses induced by three plant growth promoting rhizobacteria (PGPR) on Arabidopsis thaliana Col 0 against Pseudomonas syringae pv. tomato DC3000 at the biochemical and transcriptional levels is reported in this paper. All three strains decreased disease severity when applied to A. thaliana prior to pathogen inoculation. At the biochemical level, each of the three strains induced ethylene (ET) when incubated with 1-amino-cyclopropane-1-carboxylic acid, and salicylic acid (SA) production in the plant. Plants treated with each of the three strains were also reduced in salicylic acid production after pathogen challenge compared to untreated controls. This effect was more marked in plants treated with Chryseobacterium balustinum AUR9, the strain most effective in decreasing disease severity. The expression level of PR1, a transcriptional marker of the SA-dependent pathway in C. balustinum AUR9-treated plants, is fourfold that of controls while the expression of PDF1.2, a transcriptional marker for the SA-independent pathway, is not induced. C. balustinum cell wall lipopolysaccharides, being putative bacterial elicitor molecules, are able to reproduce this systemic induction effect at low doses. From these observations, we hypothesize that certain PGPR strains are capable of stimulating different systemic responses in host plants. With C. balustinum AUR9, the SA-dependent pathway is stimulated first, as indicated by increases in SA levels and PR1 expression, followed by induction of the SA-independent pathway, as indicated by the increases in ET concentrations. The effects of both pathways combined with respect to disease suppression appear to be additive.
Biological and Phylogenetic Characterization of Fusarium oxysporum Complex, Which Causes Yellows on Brassica spp., and Proposal of F. oxysporum f. sp. rapae, a Novel Forma Specialis Pathogenic on B. rapa in Japan
Authors: Enya J. , Togawa M. , Takeuchi T. , Yoshida S. , Tsushima S. , Arie T. , Sakai T.
Published: March 2008

Although the causal agent of yellows of Brassica rapa (turnip, pak choi, and narinosa) in Japan was reported in 1996 to be Fusarium oxysporum f. sp. conglutinans, this classification has remained inconclusive because of a lack of detailed genetic and pathogenic studies. Therefore, we analyzed the taxonomic position of this organism using Japanese isolates of F. oxysporum complex obtained from diseased individuals of various B. rapa subspecies. Phylogenetic analyses using partial sequences of the rDNA intergenic spacer region and the mating-type gene (MAT1-1-1α-box) showed that B. rapa and cabbage isolates belong to different monophyletic clades that separated at early evolutionary stages. Additionally, correlations were observed between the molecular phylogeny and the vegetative compatibility groups. Isolates from turnip, komatsuna, and narinosa (B. rapa group) did not show pathogenicity against cabbage or broccoli (B. oleracea group), although they caused severe symptoms on their original host species. In contrast, cabbage isolates had significantly higher (P = 0.05) virulence on B. oleracea than on B. rapa crops. Our results indicate that F. oxysporum complex isolates from B. rapa and B. oleracea are not only phylogenetically distinct but also differ in host specificity. Therefore, we propose a novel forma specialis, F. oxysporum f. sp. rapae, which causes yellows on B. rapa, including turnip, komatsuna, pak choi, and narinosa.
Female sperm limitation in natural populations of a sexual/asexual mating complex (
Poecilia latipinna
,
Poecilia formosa
)
Authors: Riesch Rüdiger , Schlupp Ingo , Plath Martin
Published: March 2008

In sperm-dependent sexual/asexual mating systems, male mate choice is critical for understanding the mechanisms behind apparent stability observed in natural populations. The gynogenetic Amazon molly (
Poecilia formosa
) requires sperm from sexual males (e.g.
Poecilia latipinna
) to trigger embryogenesis, but inheritance is strictly maternal. Consequently, males should try to avoid or reduce the cost of mating with asexuals. We investigated male mate choice by documenting the presence of sperm in natural populations and found that a higher proportion of sexual females had sperm than asexuals. In addition, among those females that had sperm, sexuals had more sperm than asexuals. Our results hint at a role for male mate choice as a stabilizing factor in such systems.
A new, nearly complete stem turtle from the Jurassic of South America with implications for turtle evolution
Authors: Sterli Juliana
Published: March 2008

Turtles have been known since the Upper Triassic (210 Myr old); however, fossils recording the first steps of turtle evolution are scarce and often fragmentary. As a consequence, one of the main questions is whether living turtles (Testudines) originated during the Late Triassic (210 Myr old) or during the Middle to Late Jurassic (
ca
160 Myr old). The discovery of the new fossil turtle,
Condorchelys antiqua
gen. et sp. nov., from the Middle to Upper Jurassic (
ca
160–146 Myr old) of South America (Patagonia, Argentina), presented here sheds new light on early turtle evolution. An updated cladistic analysis of turtles shows that
C. antiqua
and other fossil turtles are not crown turtles, but stem turtles. This cladistic analysis also shows that stem turtles were more diverse than previously thought, and that until the Middle to Upper Jurassic there were turtles without the modern jaw closure mechanism.
Modelling heterogeneity and the impact of chemotherapy and vaccination against human hookworm
Authors: Sabatelli L , Ghani A.C , Rodrigues L.C , Hotez P.J , Brooker S
Published: March 2008

There is a growing emphasis on the development of vaccines against helminths (worms), and mathematical models provide a useful tool to assess the impact of new vaccines under a range of scenarios. The present study describes a stochastic individual-based model to assess the relative impact of chemotherapy and vaccination against human hookworm infection and investigates the implications of potential correlations between risk of infection and vaccine efficacy. Vaccination is simulated as a reduction in susceptibility to infection and the model includes population heterogeneities and dynamical waning of protection. To help identify appropriate measures of vaccine impact, we present a novel framework to quantify the vaccine impact on the infection-associated morbidity and introduce a measure of symmetry to study the correspondence between reduction in intensity and reduction in morbidity. Our modelling shows that, in high-transmission settings, the greatest impact of vaccination will be attained when vaccine efficacy is the greatest among individuals harbouring the heaviest worm burdens, and that the decline of morbidity primarily depends on the level of protection attained in the most at risk 8–12% of the population. We also demonstrate that if risk of infection and vaccine protection are correlated, there is not always a direct correspondence between the reduction in worm burden and in morbidity, with the precise relationship varying according to transmission setting.
Robust bi-level optimization models in transportation science
Authors: Patriksson Michael
Published: March 2008

Mathematical programmes with equilibrium constraints (MPECs) constitute important modelling tools for network flow problems, as they place ‘what-if’ analyses in a proper mathematical framework. We consider a class of stochastic MPEC traffic models that explicitly incorporate possible uncertainties in travel costs and demands. In stochastic programming terminology, we consider ‘here-and-now’ models where decisions must be made before observing the uncertain parameter values and the responses of the network users; the objective is to minimize the expectation of the upper-level objective function. Such a model could, for example, be used to derive a fixed toll pricing scheme that provides the best revenue for a given network over a time period, where variations in traffic conditions and demand elasticities are described by distributions of parameters in the travel time and demand functions.

We present new results on the stability of globally optimal solutions to perturbations in the probability distribution, establishing the robustness of the model. We also discuss penalization and discretization algorithms, the latter enabling the use of standard MPEC algorithms, and provide many future research avenues.
Transport networks and their use: how real can modelling get?
Authors: Allsop Richard E
Published: March 2008

The context for modelling transport systems and their use is set out. Such modelling is based on representing the transport system by a network of nodes and links, and the characteristics of this representation needed to reflect the principal realities of the system are outlined. The characteristics of use of the system that need to be reflected are described. Purposes of the modelling are set out and its evolution is described, starting from the basic traffic assignment model and discussing its generalizations and extensions in the search for greater realism—first in steady-state modelling for fixed demand, and then considering variable demand and time dependence. Further progress towards appropriate realism is seen as requiring communication and cooperation between the modellers and the users of models, helped perhaps by combining the advantages of analytical modelling and microsimulation.
Mechanisms for spatio-temporal pattern formation in highway traffic models
Authors: Wilson R. Eddie
Published: March 2008

A key qualitative requirement for highway traffic models is the ability to replicate a type of traffic jam popularly referred to as a
phantom jam
,
shock wave
or
stop-and-go wave
. Despite over 50 years of modelling, the precise mechanisms for the generation and propagation of stop-and-go waves and the associated spatio-temporal patterns are in dispute. However, the increasing availability of empirical datasets, such as those collected from motorway incident detection and automatic signalling system (MIDAS) inductance loops in the UK or the next-generation simulation trajectory data (NGSIM) project in the USA, means that we can expect to resolve these questions definitively in the next few years. This paper will survey the essence of the competing explanations of highway traffic pattern formation and introduce and analyse a new mechanism, based on dynamical systems theory and bistability, which can help resolve the conflict.
Metabolic acidosis in the critically ill: Part 2. Causes and treatment
Authors: Morris C. G. , Low J.
Published: March 2008

The correct identification of the cause, and ideally the individual acid, responsible for metabolic acidosis in the critically ill ensures rational management. In Part 2 of this review, we examine the elevated (corrected) anion gap acidoses (lactic, ketones, uraemic and toxin ingestion) and contrast them with nonelevated conditions (bicarbonate wasting, renal tubular acidoses and iatrogenic hyperchloraemia) using readily available base excess and anion gap techniques. The potentially erroneous interpretation of elevated lactate signifying cell ischaemia is highlighted. We provide diagnostic and therapeutic guidance when faced with a high anion gap acidosis, for example pyroglutamate, in the common clinical scenario ‘I can’t identify the acid – but I know it's there'. The evidence that metabolic acidosis affects outcomes and thus warrants correction is considered and we provide management guidance including extracorporeal removal and fomepizole therapy.