bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence that solar wind fluctuations substantially affect global convection and substorm occurrence
Authors: Lyons L. R. , Kim H.‐J. , Xing X. , Zou S. , Lee D.‐Y. , Heinselman C. , Nicolls M. J. , Angelopoulos V. , Larson D. , McFadden J. , Runov A. , Fornacon K.‐H.
Published: November 2009

We have used examples of Poker Flat and Sondrestrom incoherent‐scatter radar observations of flows within the ionospheric mapping of the nightside plasma sheet and of Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft observations within the nightside plasma sheet to investigate whether the features found in the companion paper by Kim et al. (2009) within the dayside polar cap are also seen within the nightside plasma sheet. We find evidence that this is indeed the case: intensified interplanetary ULF fluctuations substantially enhance nightside convection flows and the fluctuations are reflected in the fluctuation power of the nightside flows. Additionally, our observations show evidence for an enhancement of earthward convection within the inner plasma sheet and an increase in plasma pressure within the plasma sheet in association with enhanced interplanetary ULF fluctuations. We have also found evidence that the enhancement in convection and plasma sheet pressure associated with strong interplanetary fluctuations may lead to a dramatic increase in substorm occurrence under northward interplanetary magnetic field conditions. More detailed testing of the above results is needed. However, if corroborated, it would indicate that interplanetary ULF fluctuations have a substantial effect on global convection and are an important contributor to the large‐scale transfer of solar wind energy to the magnetosphere‐ionosphere system, to plasma sheet structure and dynamics, and to the occurrence of disturbances such as substorms.
In situ observations of reconnection Hall magnetic fields at Mars: Evidence for ion diffusion region encounters
Authors: Halekas J. S. , Eastwood J. P. , Brain D. A. , Phan T. D. , Øieroset M. , Lin R. P.
Published: November 2009

We present Mars Global Surveyor measurements of bipolar out‐of‐plane magnetic fields at current sheets in Mars' magnetosphere. These signatures match predictions from simulations and terrestrial observations of collisionless magnetic reconnection, and could similarly indicate differential ion and electron motion and the resulting Hall current systems near magnetic X lines. Thus, these observations may represent passages through or very near reconnection diffusion regions at Mars. Out of 28 events found at 400 km altitude with well‐defined current sheet orientations, 26 have magnetic fields consistent with the expected polarities of Hall fields near diffusion regions. For these events, we find an average ratio of Hall field to main field of 0.51 ± 0.13, and an average ratio of normal to main field (reconnection rate) of 0.16 ± 0.09, consistent with terrestrial observations of reconnection. These events do not consistently correlate with the location of crustal fields or with IMF reversals, indicating that magnetic field draping alone (perhaps enhanced by high solar wind dynamic pressure) may generate current sheets capable of reconnection. For some events, we observe field‐aligned electrons that may carry parallel currents that close the Hall current loop. Electron distributions around current sheets often indicate magnetic connection to the collisional exosphere. For crossings sunward of the X line, we usually observe an electron flux minimum at the current sheet, consistent with the resulting closed magnetic structure. For crossings antisunward of the X line, we do not observe flux minima, consistent with field lines open downstream. Collisionless reconnection, if common at Mars, could represent a significant atmospheric loss process.
The Relationship between the UniProt Knowledgebase (UniProtKB) and the IntAct Molecular Interaction Databases
Authors: Alam-Faruque Yasmin
Published: November 2009

IntAct provides a freely available, open source database system and analysis tools for protein interaction data. All interactions are derived from literature curation or direct user submission and all experimental information relating to binary protein-proteininteractions is entered into the IntAct database by curators, via a web-based editor. Interaction information is added to the SUBUNIT comment and the RP line of the relevant publication within the UniProtKB entry. There may be a single INTERACTION comment present within a UniProtKB entry, which conveys information relevant to binary protein-protein interactions. This is automatically derived from the IntAct database and is updated on a triweekly basis. Interactions can be derived by any appropriate experimental method but must be confirmed by a second interaction if resulting from a single yeast2hybrid experiment. For large-scale experiments, interactions are considered if a high confidence score is assigned by the authors. The INTERACTION line contains a direct link to IntAct that provides detailed information for the experimental support. These lines are not changed manually and any discrepancy is reported to IntAct for updates. There is also a database crossreference line within the UniProtKB entry i.e.: DR IntAct _UniProtKB AC, which directs the user to additional interaction data for that molecule. UniProt is supported by grants from the National Institutes of Health, European Commission, Swiss Federal Government and PATRIC BRC.IntAct is funded by the European Commission under FELICS, contract number 021902 (RII3) within the Research Infrastructure Action of the FP6 "Structuring the European Research Area" Programme.
Fishing in the (deoxyribonucleotide) pool
Authors: Saada Ann
Published: November 2009

Deoxyribonucleoside triphosphates (dNTPs) are the building blocks of DNA, and a constant supply is essential for the synthesis and maintenance of both the nuclear and mitochondrial genomes. Antiviral nucleoside analogues and inborn errors of nucleotide metabolism frequently cause dNTP pool imbalances, leading to depletion of mtDNA (mitochondrial DNA) in non-replicating tissues. mtDNA depletion, in turn, causes failure of the mitochondrial respiratory chain, resulting in cellular energy depletion and cell death. Accordingly, it is important to understand the origin and regulation of dNTPs in order to develop safe and effective treatments. In this issue of the Biochemical Journal, Morris et al. have pursued the origin of pyrimidines in perfused adult rat heart. They found no evident role for the nucleotide de novo synthesis pathway and also demonstrated that AZT (3′-azido-3′-deoxythymidine; also known as zidovudine) substantially decreased the TTP pool. Their results underscore the general importance of the mitochondrial deoxyribonucleoside salvage pathway in adult tissues, and particularly in AZT-mediated toxicity. Although the role of nucleoside salvaging versus de novo synthesis in humans remains unclear, the study of tissue cultures and animal models contribute to the understanding of the intricate network of biochemical pathways, maintaining the cellular dNTP supply.
The study of plasma plume induced by pulsed laser ablation of silicon
Authors: Huang Qing-Ju , Chen Jian-Wen
Published: November 2009

Some photographs of laser-induced silicon plasma plume are obtained through synchronous photographs. The experimental results show that the plasma plume has different color properties at different areas. Each area of the plasma plume decreases gradually as gas pressure increases, and color becomes lighter as the atmospheric pressure increases. The main light-emission excitation mechanisms of plasma plume at different areas are analyzed. The excitation mechanism of the central area is bremsstrahlung, as for medial area, it is the combination excitation of electrons and ions, while in the outermost area, it is due to the collision excitation of electrons and atoms.
Light emitting field effect transistor with two self-aligned Si nanocrystal layers
Authors: Beyer V. , Schmidt B. , Heinig K.-H. , Stegemann K.-H.
Published: November 2009

Light emitting field effect transistors based on narrow layers of silicon nanocrystals (NCs) in the gate oxide were fabricated. Direct quantum mechanical electron and hole tunneling into NCs was achieved by self-alignment of NCs-interface-distances to ∼2 nm. The direct tunneling reduces oxide degradation, prolongs device lifetime and increases operation speed. Self-alignment occurs during thermal treatment of ion irradiated stacks of 50 nm polycrystalline silicon/15 nm SiO2/(001)Si substrate. An alternating voltage (ac) was applied to the gate to inject charges into the NCs. Due to injection by direct tunneling, electroluminescence extends to higher ac frequencies than reported so far.
Acoustoelectric effects in very high-mobility p-SiGe/Ge/SiGe heterostructure
Authors: Drichko I. L. , Diakonov A. M. , Lebedeva E. V. , Smirnov I. Yu. , Mironov O. A. , Kummer M. , von Känel H.
Published: November 2009

Measurement results of the acoustoelectric effects [surface acoustic waves (SAW) attenuation and velocity] in a high-mobility p-SiGe/Ge/SiGe structure are presented. The structure was low-energy plasma-enhanced chemical vapor deposition grown with a two-dimensional (2D) channel buried in the strained Ge layer. The measurements were performed as a function of temperature (1.5–4.2 K) and magnetic field (up to 8.4 T) at different SAW intensities at frequencies 28 and 87 MHz. Shubnikov–de Haas-like oscillations of both SAW attenuation and the velocity change have been observed. Hole density and mobility, effective mass, quantum and transport relaxation times, as well as the Dingle temperature were measured with a method free of electric contacts. The effect of heating of the 2D hole gas by the electric field of the SAW was investigated. Energy relaxation time τε and the deformation potential constant determined.
Adjusting the resonant frequency and loss of dendritic left-handed metamaterials with fractal dimension
Authors: Zhu Weiren , Zhao Xiaopeng
Published: November 2009

Left-handed metamaterials (LHMs) with fractal dendritic cells have recently been demonstrated at both microwave and infrared frequencies. Here, we try to utilize only a single parameter, the fractal dimension, to manipulate the geometries of dendritic structures, and then adjust the resonant behaviors and lossy characteristics of the dendritic LHMs. Both the dendritic LHMs for electromagnetic wave parallel and normal incidences are discussed in this paper. As the fractal dimension increases, the left-handed resonant frequency of the dendritic LHMs decreases, and the lossy characteristics could be well adjusted. The method proposed in this paper could be an important guidance for LHMs’ design, especially for the dendritic LHMs operating at optical frequencies.
Development of a straightness measurement and compensation system with multiple right-angle reflectors and a lead zirconate titanate-based compensation stage
Authors: Liu Chien-Hung , Chen Jui-Hung , Teng Yun-Feng
Published: November 2009

This paper presents a real-time straightness measurement and compensation system with an optical straightness measurement system and a single-axis flexure-hinge type lead zirconate titanate (PZT)-based compensation stage. The optical straightness measurement system consists of a He–Ne laser, a quadrant photodiode detector, and five right-angle reflectors. Multiple laser beam reflections between the right-angle reflectors increase the sensitivity of the straightness measurement by a factor of 6. The right-angle reflectors can be moved by the flexure-hinge type PZT-based compensation stage that is actuated by a PZT actuator to ensure that the laser beam is always projected onto the center of the quadrant detector. These two systems are integrated and fixed on a scanning stage. The resolution of the straightness measurement system is 0.1 μm. Using the real-time straightness compensation system, the straightness error of the scanning stage is fed back to the control system. The compensated straightness error of the scanning stage system was reduced from 6.5 μm to less than 1 μm.
A note on superlinear Hamiltonian elliptic systems
Authors: Zhao Fukun , Zhao Leiga , Ding Yanheng
Published: November 2009

This paper is concerned with the superlinear periodic elliptic systems of Hamiltonian type in the whole space. The existence of a ground state solution as well as an infinite number of geometrically distinct solutions is obtained.
N codoping induced ferromagnetism in ZnO:Co (101¯) thin films
Authors: Assadi M. H. N. , Zhang Y. B. , Li S.
Published: November 2009

By first-principles density functional calculations with generalized gradient approximation ZnO:Co (101¯0) thin films have been demonstrated not to exhibit a ferromagnetic behavior in the absence of any additional carrier doping. Virtual crystal approximation is employed to introduce controlled hole concentrations by N codoping in dilute concentrations of 1–5 at. %. The results show that N codoping can change the ground state from antiferromagnetic to ferromagnetic while maximum ferromagnetic state stability occurs for a N concentration of 2 at. % which is practically achievable. Density of states analyses confirm that the substitutional N in the ZnO:Co thin film provides shallow acceptor states. N codoping is suggested to be a promising technique to realize p-type dilute magnetic semiconducting thin films in the dominantly paramagnetic ZnO:Co (101¯0) system.
Temperature dependence of ministop band in double-slots photonic crystal waveguides
Authors: Cui Kaiyu , Huang Yidong , Zhang Gengyan , Li Yongzhuo , Tang Xuan , Mao Xiaoyu , Zhao Qiang , Zhang Wei , Peng Jiangde
Published: November 2009

We proposed and fabricated a double-slots photonic crystal waveguides (PCWGs) structure formed by introducing two slots into PCWGs with air-bridge structure on silicon-on-insulator substrate. The mode characteristics of double-slots PCWGs were investigated theoretically and experimentally. The transmission spectra present a sharp and deep dip (22 dB with bandwidth of 6 nm) caused by ministop band in the proposed structure, which is 15 dB deeper than that in the W3 PCWG. Additionally, dependence of the dip on temperature in the double-slots PCWG was measured and a temperature coefficient 0.159 nm/°C can be concluded.
Locating La atoms in epitaxial Bi3.25La0.75Ti3O12 films through atomic resolution electron energy loss spectroscopy mapping
Authors: Gunawan L. , Lazar S. , Gautreau O. , Harnagea C. , Pignolet A. , Botton G. A.
Published: November 2009

Atomic resolution high-angle annular dark-field imaging of La-doped bismuth titanate (BLT), Bi3.25La0.75Ti3O12, has been carried out with an aberration-corrected transmission electron microscope. The HAADF image revealed the presence of defects in the [Bi2O2]2+ layers and extra atomic rows between the [Bi2O2]2+ layers and the [Bi2Ti3O10]2− perovskite slabs. Electron energy loss spectroscopy elemental mapping at atomic resolution revealed the exact location of La dopants in the bismuth titanate parent unit cell. These results are discussed in terms of large remanent polarization and enhanced fatigue resistance in BLT.
The velocity spectra and turbulence length scale distributions in the near to intermediate regions of a round free turbulent jet
Authors: Fellouah Hachimi , Pollard Andrew
Published: November 2009

Stationary and flying single hot-wire measurements were made to investigate the near to intermediate field in a round free turbulent jet. Measurements were carried out at Reynolds numbers ReD based on the jet exit mean velocity and the nozzle diameter, between 6000 and 100 000. The objective of this study was to investigate the concept of a mixing transition proposed by Dimotakis [“The mixing transition in turbulent flows,” J. Fluid Mech. 409, 69 (2000)]. This was done through the measurement of the velocity spectra and the calculation of Kolmogorov λK, Taylor microscale λT, the Liepmann–Taylor microscale λL, and the viscous length scale λν at different positions in the near to intermediate regions of a round free jet. The present results demonstrate the local nature of mixing transition. It is found that the Kolmogorov, Taylor, and viscous length scales all decrease in magnitude with the local Reynolds number Reδ based on the local center line mean velocity and the local time-averaged diameter of the jet and appear to be only weakly dependent on the radial position, although the ratio ReT∕Reδ1∕2 varies nonlinearly across the jet radius. The ratio of the laminar to viscous length scale exceeds unity beyond the potential core of the jet. Moreover, the skewness of the axial velocity is approximately −0.4 over 30<ReT<400.
Improved conformal coatings by oblique-angle deposition for bioreplication
Authors: Pulsifer Drew P. , Lakhtakia Akhlesh , Martín-Palma Raúl J.
Published: November 2009

The conformal-evaporated-film-by-rotation (CEFR) technique, a bioreplication method to produce high-fidelity conformal coatings on biotemplates by oblique-angle deposition, was modified to improve the uniformity of coating thickness. The substrate holding the biotemplate was rocked, in addition to rotating it about an axis passing normally through it. With the compound eyes of the common blow fly as the biotemplate, quantitative comparison of coating thickness obtained by the original CEFR and the modified CEFR techniques showed the superiority of the latter.
Nanoparticle plasma ejected directly from solid copper by localized microwaves
Authors: Jerby E. , Golts A. , Shamir Y. , Wonde S. , Mitchell J. B. A. , LeGarrec J. L. , Narayanan T. , Sztucki M. , Ashkenazi D. , Barkay Z. , Eliaz N.
Published: November 2009

A plasma column ejected directly from solid copper by localized microwaves is studied. The effect stems from an induced hotspot that melts and emits ionized copper vapors as a confined fire column. Nanoparticles of ∼20–120 nm size were revealed in the ejected column by in situ small-angle x-ray scattering. Optical spectroscopy confirmed the dominance of copper particles in the plasma column originating directly from the copper substrate. Nano- and macroparticles of copper were verified also by ex situ scanning electron microscopy. The direct conversion of solid metals to nanoparticles is demonstrated and various applications are proposed.
Experimental and numerical investigations of flow structure and momentum transport in a turbulent buoyancy-driven flow inside a tilted tube
Authors: Znaien J. , Hallez Y. , Moisy F. , Magnaudet J. , Hulin J. P. , Salin D. , Hinch E. J.
Published: November 2009

Buoyancy-driven turbulent mixing of fluids of slightly different densities [At=Δρ/(2⟨ρ⟩)=1.15×10−2] in a long circular tube tilted at an angle θ=15° from the vertical is studied at the local scale, both experimentally from particle image velocimetry and laser induced fluorescence measurements in the vertical diametrical plane and numerically throughout the tube using direct numerical simulation. In a given cross section of the tube, the axial mean velocity and the mean concentration both vary linearly with the crosswise distance z from the tube axis in the central 70% of the diameter. A small crosswise velocity component is detected in the measurement plane and is found to result from a four-cell mean secondary flow associated with a nonzero streamwise component of the vorticity. In the central region of the tube cross section, the intensities of the three turbulent velocity fluctuations are found to be strongly different, that of the streamwise fluctuation being more than twice larger than that of the spanwise fluctuation which itself is about 50% larger than that of the crosswise fluctuation. This marked anisotropy indicates that the turbulent structure is close to that observed in homogeneous turbulent shear flows. Still in the central region, the turbulent shear stress dominates over the viscous stress and reaches a maximum on the tube axis. Its crosswise variation is approximately accounted for by a mixing length whose value is about one-tenth of the tube diameter. The momentum exchange in the core of the cross section takes place between its lower and higher density parts and there is no net momentum exchange between the core and the near-wall regions. A sizable part of this transfer is due both to the mean secondary flow and to the spanwise turbulent shear stress. Near-wall regions located beyond the location of the extrema of the axial velocity (|z|≳0.36 d) are dominated by viscous stresses which transfer momentum toward (from) the wall near the top (bottom) of the tube.
Plasmon-enhanced heat dissipation in GaN-based two-dimensional channels
Authors: Matulionis A. , Liberis J. , Matulionienė I. , Ramonas M. , Šermukšnis E. , Leach J. H. , Wu M. , Ni X. , Li X. , Morkoç H.
Published: November 2009

Decay of nonequilibrium longitudinal optical (LO) phonons is investigated at room temperature in two-dimensional electron gas channels confined in nearly lattice-matched InAlN/AlN/GaN structures. A nonmonotonous dependence of the LO-phonon lifetime on the supplied electric power is reported for the first time and explained in terms of plasmon–LO-phonon resonance tuned by applied bias at a fixed sheet density (8×1012 cm−2). The shortest lifetime of 30±15 fs is found at the power of 20±10 nW/electron.
Onset of flow separation for the oblique water impact of a wedge
Authors: Semenov Yuriy A. , Yoon Bum-Sang
Published: November 2009

For the oblique impact of a wedge on a liquid half space, the limiting angles of the entry velocity and the wedge orientation corresponding to flow separation from the wedge vertex during the initial stage of the impact are investigated on the basis of an analytical solution of the problem. The liquid is assumed to be ideal and incompressible; gravity, surface tension, and air cushioning effects are ignored. The flow generated by the impact is two dimensional and potential. The solution is presented in terms of two governing expressions, which are the complex velocity and the derivative of the complex potential defined in a parameter region. These expressions are obtained using generalized integral formulas for solving mixed and uniform boundary-value problems for the first quadrant. They include two unknown functions, which are the velocity magnitude and angle to the free surface determined from the dynamic and kinematic boundary conditions. The obtained system of integral equations is solved by using the method of successive approximations. The effect of the horizontal component of the entry velocity is studied for various wedge orientations. The analysis of the computations revealed configurations of the impact such that the pressure along the whole length of one side of the wedge becomes less than the pressure on the free surface. Although air effects are not included in the analysis, such a pressure distribution provides conditions for the ventilation of the wedge side, which, in the presence of the air, starts from the contact point on the free surface and extends suddenly along the whole length of the wedge side, thus leading to flow separation from the wedge vertex. The theoretical predictions of flow separation and the experimental data on flow separation by Judge et al. [“Initial water impact of a wedge at vertical and oblique angles,” J. Eng. Math. 48, 279 (2004)] are remarkably close to each other.
Suppression of compensation from nitrogen and carbon related defects for p-type N-doped ZnO
Authors: Tang Kun , Gu Shulin , Zhu Shunming , Liu Jiagao , Chen Hui , Ye Jiandong , Zhang Rong , Zheng Youdou
Published: November 2009

In this letter, the authors performed a comprehensive study on suppression mechanism of compensation from nitrogen and carbon related complex defects in N-doped ZnO grown by metal-organic chemical vapor deposition. The chemical bonding information of donorlike substitutional complex defects, (NN)O and (NC)O, were restrained with low N/O ratio, leading to the conduction type conversion. High epitaxial temperature has more suppressing effect on the formation of desired acceptor NO than that of (NC)O, as evident by the decreasing hole concentration. Upon utilization of such suppression effect, this study provides a promising route to realize p-type ZnO.
Role and interrelationship of PTPases and H2O2 in light/dark-regulated stomatal movement in Vicia faba
Authors: Zhang Yuanhua , She Xiaoping , Zhang Guangbin
Published: November 2009

Role and interrelationship of protein tyrosine phosphatases (PTPases) and H2O2 in light/dark-regulated stomatal movement in Vicia faba were investigated by epidermal strip bioassay, laser-scanning confocal microscopy and assays of PTPase activity. Our results indicate that phenylarsine oxide (PAO), a specific inhibitor of PTPases, ascorbic acid (ASA), an important reducing substrate for H2O2 removal, and catalase (CAT), one of the H2O2 scavenging enzymes, did not cause any change of stomatal aperture in light, but remarkably prevented dark-induced stomatal closure. Exogenous H2O2 had no obvious effect on stomatal aperture in the dark, but significantly induced stomatal closure in light. Both PTPase activity in epidermal strips and endogenous H2O2 level in guard cells in the dark were higher than those in light. The results showed that both PTPases and H2O2 mediate light/dark-regulated stomatal movement, that dark-induced stomatal closure requires the activation of PTPases and the enhancement of H2O2 levels in guard cells, and stomatal opening caused by light is associated with the inactivation of PTPases and the reduction of H2O2 levels in guard cells. Additionally, like ASA and CAT, PAO abolished dark-, exogenous H2O2-induced stomatal closure and dichlorofluorescein fluorescence in guard cells, indicating that activation of PTPases can enhance H2O2 levels probably via suppressing the decrease of H2O2 levels in guard cells. On the other hand, similar to PAO, ASA and CAT evidently prevented dark-, exogenous H2O2-induced stomatal closure and obviously inactivated PTPases in the dark. However, exogenous H2O2 significantly activated PTPases in light. The results show that H2O2 can induce activation of PTPases. Taken together, the present results provide evidence that both H2O2 and PTPases are involved in light/dark-regulated stomatal movement, and the interaction between H2O2 and PTPases plays a pivotal role in light/dark signal transduction process in guard cells.
Reproductive biology, post-fire succession dynamics and population viability analysis of the critically endangered Western Australian shrub Calytrix breviseta subsp. breviseta (Myrtaceae)
Authors: Nield Andrew P. , Ladd Philip G. , Yates Colin J.
Published: November 2009

Calytrix breviseta Lindl. subsp. breviseta is a critically endangered, obligate-seeder shrub within fire-prone kwongan of south-west Western Australia. Little is known about the species’ reproductive biology and how threatening processes, particularly altered fire regimes and exotic species invasion, will impact the long-term viability of the species. This study aims to elucidate the species’ reproductive biology and patterns of seedling recruitment during succession after fire. The effects of changes to the fire return interval and exotic species invasion on the long-term viability of the species is also described. The species exhibits abundant recruitment following fire and the application of a smoke treatment significantly improves germination, similar to many other Western Australian shrubs. However, significant inter-fire recruitment was observed up to 10 years following fire, leading to the presence of multi-aged subpopulations, although seedling recruitment was negligible >20 years after fire. The juvenile period is short at 3–4 years to first flowering. Population viability analysis (PVA) predicted that the optimal fire return interval to maintain C. breviseta subsp. breviseta was dependent on the carrying capacity (K) of the community and the number of individuals present. Carrying capacity will be related to site quality and competition from invasive species. PVA showed that if K remains high, then the optimal fire return interval is ~15–20 years, but under lower carrying capacity, (i.e. weed competition) fires decrease the likelihood of population survival.
Francis Lions, A Memoir and Contemporary Historical Assessment: Sydney University Chemistry, 1930s to 1960s
Authors: Birch Arthur J.
Published: November 2009

A distinguished participant's account of Organic Chemistry at the University of Sydney in the middle decades of the twentieth century, focusing on the career of Francis Lions who is presented as a seminal figure in the history of this remarkable school.
From Beverley Disease to Braxy to Enterotoxaemia: the Journey of a Disease in Western Australian Livestock and the Transmission of Veterinary Knowledge in Australasia
Authors: Edwards Natalie
Published: November 2009

This article examines Australasian scientific investigations into the ?braxy-like' diseases experienced by livestock in the first part of the twentieth century. It concentrates on one of these diseases in the context of the Western Australian livestock industry and argues that environmental, social and political forces influenced changes in approach to the disease in that state. The braxy-like disease episode straddled a shift in Western Australian practices, a shift from nineteenth-century regulatory and environmental controls to increasing involvement in a twentieth-century network of veterinary science. The article addresses the question as to how local context influenced the transmission of scientific theory and method. It also investigates Australasian veterinary scientists' concurrent and inter-related pursuits of bacteriological and ecological understanding and their applications of science to the practical problems of local livestock industries.
Simple cellular and network control principles govern complex patterns of motor behavior
Authors: Kozlov Alexander , Huss Mikael , Lansner Anders , Kotaleski Jeanette Hellgren , Grillner Sten
Published: November 2009

The vertebrate central nervous system is organized in modules that independently execute sophisticated tasks. Such modules are flexibly controlled and operate with a considerable degree of autonomy. One example is locomotion generated by spinal central pattern generator networks (CPGs) that shape the detailed motor output. The level of activity is controlled from brainstem locomotor command centers, which in turn, are under the control of the basal ganglia. By using a biophysically detailed, full-scale computational model of the lamprey CPG (10,000 neurons) and its brainstem/forebrain control, we demonstrate general control principles that can adapt the network to different demands. Forward or backward locomotion and steering can be flexibly controlled by local synaptic effects limited to only the very rostral part of the network. Variability in response properties within each neuronal population is an essential feature and assures a constant phase delay along the cord for different locomotor speeds.
Multiple myeloma phosphotyrosine proteomic profile associated with FGFR3 expression, ligand activation, and drug inhibition
Authors: St-Germain Jonathan R. , Taylor Paul , Tong Jiefei , Jin Lily L. , Nikolic Ana , Stewart Ian I. , Ewing Robert M. , Dharsee Moyez , Li Zhihua , Trudel Suzanne , Moran Michael F.
Published: November 2009

Signaling by growth factor receptor tyrosine kinases is manifest through networks of proteins that are substrates and/or bind to the activated receptors. FGF receptor-3 (FGFR3) is a drug target in a subset of human multiple myelomas (MM) and is mutationally activated in some cervical and colon and many bladder cancers and in certain skeletal dysplasias. To define the FGFR3 network in multiple myeloma, mass spectrometry was used to identify and quantify phosphotyrosine (pY) sites modulated by FGFR3 activation and inhibition in myeloma-derived KMS11 cells. Label-free quantification of peptide ion currents indicated the activation of FGFR3 by phosphorylation of tandem tyrosines in the kinase domain activation loop when cellular pY phosphatases were inhibited by pervanadate. Among the 175 proteins that accumulated pY in response to pervanadate was a subset of 52 including FGFR3 that contained a total of 61 pY sites that were sensitive to inhibition by the FGFR3 inhibitor PD173074. The FGFR3 isoform containing the tandem pY motif in its activation loop was targeted by PD173074. Forty of the drug-sensitive pY sites, including two located within the 35-residue cytoplasmic domain of the transmembrane growth factor binding proteoglycan (and multiple myeloma biomarker) Syndecan-1/CD138, were also stimulated in cells treated with the ligand FGF1, providing additional validation of their link to FGFR3. The identification of these overlapping sets of co-modulated tyrosine phosphorylations presents an outline of an FGFR3 network in the MM model and demonstrates the potential for pharmacodynamic monitoring by label-free quantitative phospho-proteomics.
Prevention and treatment of cervical cancer in mice using estrogen receptor antagonists
Authors: Chung Sang-Hyuk , Lambert Paul F.
Published: November 2009

The majority of human cervical cancers are associated with the high-risk human papillomavirus (HPV) types. In mouse models for HPV-associated cancers, estrogen is required for the development of cervical and vaginal cancers. The estrogen receptor α (ERα) also is required in mice for these cancers to arise. These data are consistent with the observation in women that long-term use of oral contraceptives or multiple pregnancies significantly increases the risk for cervical cancer in HPV-positive women. In the present study, we examined whether drugs that interfere with the function of ERα are effective in treating and/or preventing cervical cancer in mice. We provide evidence that a complete ER antagonist, ICI 182,780 (ICI), as well as a selective ER modulator, raloxifene, efficiently clear cancer and its precursor lesions in both the cervix and the vagina. Furthermore, ICI was capable of preventing the onset of cancers in mice bearing precursor lesions. These findings point to the potential value of ER antagonists in controlling gynecological disease in the lower reproductive tracts in women.
A single polymorphic amino acid on Toxoplasma gondii kinase ROP16 determines the direct and strain-specific activation of Stat3
Authors: Yamamoto Masahiro , Standley Daron M. , Takashima Seiji , Saiga Hiroyuki , Okuyama Megumi , Kayama Hisako , Kubo Emi , Ito Hiroshi , Takaura Mutsumi , Matsuda Tadashi , Soldati-Favre Dominique , Takeda Kiyoshi
Published: November 2009

Infection by Toxoplasma gondii down-regulates the host innate immune responses, such as proinflammatory cytokine production, in a Stat3-dependent manner. A forward genetic approach recently demonstrated that the type II strain fails to suppress immune responses because of a potential defect in a highly polymorphic parasite-derived kinase, ROP16. We generated ROP16-deficient type I parasites by reverse genetics and found a severe defect in parasite-induced Stat3 activation, culminating in enhanced production of interleukin (IL) 6 and IL-12 p40 in the infected macrophages. Furthermore, overexpression of ROP16 but not ROP18 in mammalian cells resulted in Stat3 phosphorylation and strong activation of Stat3-dependent promoters. In addition, kinase-inactive ROP16 failed to activate Stat3. Comparison of type I and type II ROP16 revealed that a single amino acid substitution in the kinase domain determined the strain difference in terms of Stat3 activation. Moreover, ROP16 bound Stat3 and directly induced phosphorylation of this transcription factor. These results formally establish an essential and direct requirement of ROP16 in parasite-induced Stat3 activation and the significance of a single amino acid replacement in the function of type II ROP16.
Unramified representations of reductive groups over finite rings
Authors: Stasinski Alexander
Published: November 2009

Lusztig has given a construction of certain representations of reductive groups over finite local principal ideal rings of characteristic

p
p

, extending the construction of Deligne and Lusztig of representations of reductive groups over finite fields. We generalize Lusztig’s results to reductive groups over arbitrary finite local rings. This generalization uses the Greenberg functor and the theory of group schemes over Artinian local rings.
Effect of Modified Oat Starch and Protein on Batter Properties and Quality of Cake
Authors: Mirmoghtadaie Leila , Kadivar Mahdi , Shahedi Mohammad
Published: November 2009

Starch and protein separated from oat were chemically modified using cross‐linking and acetylation protocols for starch, and deamidation and succinylation for protein isolate. Cross‐linking decreased swelling power of starch, whereas syneresis increased, but cross‐linking does not have a significant effect on gelatinization temperature. Acetylation increased swelling power, but gelatinization temperature and syneresis diminished. Deamidation and succinylation increased nitrogen solubility index, emulsion activity, foaming capacity, and water and oil binding capacity. Emulsion stability did not change with deamidation and it diminished with succinylation, while foaming stability decreased with both treatments. Acetylated starch and two types of modified proteins were substituted for 5, 10, 15, and 20% of oat flour to bake cake samples and then physical properties of the cakes were measured. Acetylated starch increased batter viscosity, cake volume, and whiteness of cake crust. Increased level of deamidated protein produced cakes with lower batter viscosity, higher volume, and darker color (increase in redness). Application of higher levels of succinylated protein led to higher batter viscosity and lightness, and lower cake volume. Therefore, substitution of deamidated protein and acetylated starch can improve cake properties.
Effect of Fungicides on Sugar Beet Yield, Quality, and Postharvest Respiration Rates in the Absence of Disease
Authors: Khan M. F. R. , Carlson A. L.
Published: November 2009

Five fungicides were each applied on sugar beet (Beta vulgaris) three times at about 14-day intervals beginning in July in 2005 through 2008. No foliar disease occurred in the nontreated control or any fungicide treatment. There were no significant differences in root yield, recoverable sucrose, or sucrose concentration among treatments. In 2007 and 2008, postharvest storage respiration rates were determined after 30 and 90 days in storage. There was no significant difference in respiration rates among treatments. There was no apparent benefit in applying these fungicides in seasons when no foliar disease developed.

Accepted for publication 7 September 2009. Published 19 October 2009.
Quantitative Detection of Pear-Pathogenic Stemphylium vesicarium in Orchards
Authors: Köhl J. , Groenenboom-de Haas B. H. , Kastelein P. , Rossi V. , Waalwijk C.
Published: November 2009

Isolates of Stemphylium vesicarium causing brown spot of pear can be distinguished from nonpathogenic isolates of S. vesicarium from pear or from other hosts on the basis of distinctive amplified fragment length polymorphism fingerprinting profiles. DNA fragments specific for isolates pathogenic to pear were identified and a quantitative polymerase chain reaction (PCR) was developed on the sequence from one of these specific DNA loci. This TaqMan PCR has a high sensitivity with a dynamic range for reliable quantification between 1 ng and 100 fg of DNA. The method detected pear-pathogenic isolates of S. vesicarium originating from four different European countries and various regions within those countries. No cross-reaction was found with either the nonpathogenic isolates of S. vesicarium tested or isolates belonging to other Stemphylium spp. or related fungi. The pathogen was detected on leaves with brown-spot symptoms originating from six different locations in The Netherlands, Italy, and Spain. Pear-pathogenic S. vesicarium populations were monitored on crop residues in two Dutch orchards between October 2007 and October 2008. Brown spot had been observed at both orchards at the end of the growing season of 2007. In one location, pear-pathogenic S. vesicarium was detected only sporadically on crop residues and no brown-spot symptoms were observed on fruit in 2008. At the other location, a pathogenic population was found on fallen pear leaves and on other crop residues but this population decreased during winter. From the beginning of the growing season in 2008 onward, the pathogen population could not be detected and the disease incidence was only 0.6%. The TaqMan PCR will allow more detailed studies on epidemiology of brown spot and on the effect of disease control measures.
Epidemic multiple drug resistant Salmonella Typhimurium causing invasive disease in sub-Saharan Africa have a distinct genotype
Authors: Kingsley Robert A. , Msefula Chisomo L. , Thomson Nicholas R. , Kariuki Samuel , Holt Kathryn E. , Gordon Melita A. , Harris David , Clarke Louise , Whitehead Sally , Sangal Vartul , Marsh Kevin , Achtman Mark , Molyneux Malcolm E. , Cormican Martin , Parkhill Julian , MacLennan Calman A. , Heyderman Robert S. , Dougan Gordon
Published: November 2009

Whereas most nontyphoidal Salmonella (NTS) are associated with gastroenteritis, there has been a dramatic increase in reports of NTS-associated invasive disease in sub-Saharan Africa. Salmonella enterica serovar Typhimurium isolates are responsible for a significant proportion of the reported invasive NTS in this region. Multilocus sequence analysis of invasive S. Typhimurium from Malawi and Kenya identified a dominant type, designated ST313, which currently is rarely reported outside of Africa. Whole-genome sequencing of a multiple drug resistant (MDR) ST313 NTS isolate, D23580, identified a distinct prophage repertoire and a composite genetic element encoding MDR genes located on a virulence-associated plasmid. Further, there was evidence of genome degradation, including pseudogene formation and chromosomal deletions, when compared with other S. Typhimurium genome sequences. Some of this genome degradation involved genes previously implicated in virulence of S. Typhimurium or genes for which the orthologs in S. Typhi are either pseudogenes or are absent. Genome analysis of other epidemic ST313 isolates from Malawi and Kenya provided evidence for microevolution and clonal replacement in the field.
Acute alcohol impairs conditioning of a behavioural reward‐seeking response and inhibitory control processes—implications for addictive disorders
Authors: Loeber Sabine , Duka Theodora
Published: November 2009

Aims  To investigate whether acute alcohol would affect performance of a conditioned behavioural response to obtain a reward outcome and impair performance in a task measuring inhibitory control to provide new knowledge of how the acute effects of alcohol might contribute to the transition from alcohol use to dependence.

Design  A randomized controlled between‐subjects design was employed.

Settings  The laboratory of experimental psychology at the University of Sussex.

Participants  Thirty‐two light to moderate social drinkers recruited from the undergraduate and postgraduate population.

Measurements  After the administration of alcohol (0.8 g/kg) or placebo participants underwent an instrumental reward‐seeking procedure, with abstract stimuli serving as S+ (always predicting a win of 10 pence) and S− (always predicting a loss of 10 pence). In addition, a Stop Signal task was administered before and after the administration of alcohol.

Findings  Participants of the alcohol group performed the behavioural response to obtain the reward outcome more often than placebo subjects in trials associated with loss of money. This finding was observed, although alcohol was not affecting explicit knowledge of stimulus–response outcome contingencies and acquisition of conditioned attentional and emotional responses. In addition, alcohol increased Stop Signal reaction time indicating disinhibiting effects of alcohol, and this was associated positively with response probability to the S−.

Conclusions  These results demonstrate that alcohol is affecting inhibitory control of behavioural responses to external signals even when associated with punishment, contributing in this way to the transition from alcohol use to dependence.
The cost‐effectiveness of antidepressants for smoking cessation in chronic obstructive pulmonary disease (COPD) patients
Authors: Van Schayck Constant P. , Kaper Janneke , Wagena Edwin J. , Wouters Emiel F. M. , Severens Johannes L.
Published: November 2009

Objectives  In healthy smokers, antidepressants can double the odds of cessation. Because of its four times lower costs and comparable efficacy in healthy smokers, nortriptyline appears to be favourable compared to bupropion. We assessed which of both drugs was most effective and cost‐effective in stopping smoking after 1 year compared with placebo among smokers at risk or with existing chronic obstructive pulmonary disease (COPD).

Methods  A total of 255 participants, aged 30–70 years, received smoking cessation counselling and were assigned bupropion, nortriptyline or placebo randomly for 12 weeks. Prolonged abstinence from smoking was defined as a participant's report of no cigarettes from week 4 to week 52, validated by urinary cotinine. Costs were calculated using a societal perspective and uncertainty was assessed using the bootstrap method.

Results  The prolonged abstinence rate was 20.9% with bupropion, 20.0% with nortriptyline and 13.5% with placebo. The differences between bupropion and placebo [relative risk (RR) = 1.6; 95% confidence interval (CI) 0.8–3.0] and between nortriptyline and placebo (RR = 1.5; 95% CI 0.8–2.9) were not significant. Severity of airway obstruction did not influence abstinence significantly. Societal costs were €1368 (2.5th–97.5th percentile 193–5260) with bupropion, €1906 (2.5th–97.5th 120–17 761) with nortriptyline and €1212 (2.5th–97.5th 96–6602) with placebo. Were society willing to pay more than €2000 for a quitter, bupropion was most likely to be cost‐effective.

Conclusions  Bupropion and nortriptyline seem to be equally effective, but bupropion appears to be more cost‐effective when compared to placebo and nortriptyline. This impression holds using only health care costs. As the cost‐effectiveness analyses concern some uncertainties, the results should be interpreted with care and future studies are needed to replicate the findings.
The natural history of quitting smoking: findings from the International Tobacco Control (ITC) Four Country Survey
Authors: Herd Natalie , Borland Ron
Published: November 2009

Aims  To describe the long‐term natural history of a range of potential determinants of relapse from quitting smoking.

Design, setting and participants  A survey of 2502 ex‐smokers of varying lengths of time quit recruited as part of the International Tobacco Control (ITC) Four Country Survey (Australia, Canada, United Kingdom, United States) across five annual waves of surveying.

Measurements  Quitters were interviewed by telephone at varying durations of abstinence, ranging from 1 to 1472 days (about 4 years) post‐quitting. Smoking‐related beliefs and experiences (i.e. urges to smoke; outcome expectancies of smoking and quitting; and abstinence self‐efficacy) were included in the survey.

Findings  Most theorized determinants of relapse changed over time in a manner theoretically associated with reduced risk of relapse, except most notably the belief that smoking controls weight, which strengthened. Change in these determinants changed at different rates: from a rapidly asymptoting log function to a less rapidly asymptoting square‐root function.

Conclusions  Variation in patterns of change across time suggests that the relative importance of each factor to maintaining abstinence may similarly vary.