bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical and nonlinear absorption properties of Na doped ZnO nanoparticle dispersions
Authors: Karthikeyan B. , Sandeep C. S. Suchand , Pandiyarajan T. , Venkatesan P. , Philip Reji
Published: July 2009

We report linear and nonlinear optical properties of the biologically important Na doped ZnO nanoparticle dispersions. Interesting morphological changes involving a spherical to flowerlike transition have been observed with Na doping. Optical absorption measurements show an exciton absorption around 368 nm. Photoluminescence measurements reveal exciton recombination emission, along with shallow and deep trap emissions. The increased intensity of shallow trap emission with Na doping is attributed to oxygen deficiency and shape changes associated with doping. Nonlinear optical measurements show a predominantly two-photon induced, excited state absorption, when excited with 532 nm, 5 ns laser pulses, indicating potential optical limiting applications.
Characterization and comparison of nanoscale domain boundary in congruent and stoichiometric LiTaO3 with scanning nonlinear dielectric microscopy
Authors: Jeong Dae-Yong , Cho Yasuo
Published: July 2009

The domain boundary of congruent LiTaO3 (CLT) and stoichiometric LiTaO3 (SLT) were characterized on the nanoscale using scanning nonlinear dielectric microscopy. SLT exhibited a smooth domain boundary but CLT showed an irregular domain boundary. The nonlinear dielectric constant ε333 in the domain boundary of SLT changed abruptly from the domain but there was a gradual change in ε333 in the boundary of CLT. The linear dielectric constant in the domain boundary of SLT was slightly higher than that in the domain itself. In addition, the topography showed that only SLT had <1 nm dimensional deformation in the domain boundary.
Ge-based interface passivation for atomic layer deposited La-doped ZrO2 on III-V compound (GaAs,In0.15Ga0.85As) substrates
Authors: Molle Alessandro , Brammertz Guy , Lamagna Luca , Fanciulli Marco , Meuris Marc , Spiga Sabina
Published: July 2009

La-doped ZrO2 thin films were grown by O3-based atomic layer deposition on III-V (GaAs,In0.15Ga0.85As) substrates through direct growth and after intercalation of a Ge interface passivation layer. The interface composition was investigated by x-ray photoelectron spectroscopy, revealing a dramatic reduction of semiconductor-oxygen bonding upon Ge passivation. An improved electrical quality of the Ge-passivated interfaces due to the removal of Ga3+ bonding related traps is demonstrated by conductance measurements at various temperatures.
Practical vortex diodes from pinning enhanced YBa2Cu3O7−δ
Authors: Harrington S. A. , MacManus-Driscoll J. L. , Durrell J. H.
Published: July 2009

We identify a scalable, practical route to fabricating a superconducting diode. The device relies for its function on the barrier to flux vortex entry being reduced at the substrate interface of a superconducting pinning enhanced YBa2Cu3O7−δ nanocomposite film. We show that these composite systems provide a practical route to fabricating a useful superconducting diode and demonstrate the rectification of an alternating current.
High-field transport and velocity saturation in graphene
Authors: Chauhan Jyotsna , Guo Jing
Published: July 2009

High-field transport in graphene is studied by the Monte Carlo simulation. The results indicate velocity and current saturation in agreement with a recent experiment [I. Meric, M. Y. Han, A. F. Young, B. Oezyilmaz, P. Kim, and K. Shepard, Nat. Nanotechnol. 3, 654 (2008)]. The saturation current scales as the square root of the charge density, or equivalently, the square root of the gate overdrive voltage, which is qualitatively different from silicon field-effect transistors. By analytical fitting to the numerical simulation results, a simple expression of the field-dependent mobility is obtained at different strengths of charged impurity scattering.
Wide-bandgap high-k Y2O3 as passivating interlayer for enhancing the electrical properties and high-field reliability of n-Ge metal-oxide-semiconductor capacitors with high-k HfTiO gate dielectric
Authors: Li C. X. , Lai P. T.
Published: July 2009

High-k and wide-bandgap Y2O3 was proposed as an interlayer in n-Ge metal-oxide-semiconductor (MOS) capacitor with HfTiO gate dielectric for passivating its dielectric/Ge interface, and thus improving its electrical properties and high-field reliability. Results showed that as compared to the Ge MOS capacitor with HfTiO dielectric, the sample with HfTiO/Y2O3 dielectric had better electrical properties such as higher dielectric constant (k=24.4), lower interface-state density, and less frequency-dependent C-V dispersion, and also better reliability with less increases in gate leakage and interface states after high-field stressing. This should be attributed to the excellent interfacial quality of Y2O3/Ge with no appreciable growth of unstable GeOx at the interface as confirmed by transmission electron microscopy. Moreover, Y2O3 can also act as a barrier against the diffusions of Ge, Hf, and Ti, thus further improving the interface quality.
High-quality single-crystal Ge stripes on quartz substrate by rapid-melting-growth
Authors: Miyao Masanobu , Toko Kaoru , Tanaka Takanori , Sadoh Taizoh
Published: July 2009

Single-crystal Ge on a transparent insulating substrate is desired to achieve advanced thin-film transistors (TFTs) with high speed operation. We have developed the rapid-melting-growth process of amorphous Ge by using polycrystalline Si islands as the growth seed. High-quality and dominantly (100)-oriented single-crystal Ge stripes with 400 μm length are demonstrated on quartz substrates. The temperature dependence of the electrical conductivity shows a high hole mobility of 1040 cm2/V s. This method opens up a possibility of Ge-channel TFT with the high carrier mobility.
Effect of nozzle transients and compressibility on the penetration of fuel sprays
Authors: Kostas J. , Honnery D. , Soria J. , Kastengren A. , Liu Z. , Powell C. F. , Wang J.
Published: July 2009

A study has been performed using a combination of high speed optical imaging and a synchrotron based technique to obtain a time history of nozzle exit velocity, discharge coefficient, and spray tip velocity of high pressure fuel sprays. The results support a recently proposed theoretical model of spray propagation that suggests a compressible region of flow immediately ahead of the spray has a strong influence on the evolution of the tip velocity profile. Coupled with this is the variation in discharge coefficient due to injector needle movement which largely governs the spray exit velocity immediately after start of injection.
Photovoltaic mechanisms in ferroelectric thin films with the effects of the electrodes and interfaces
Authors: Qin Meng , Yao Kui , Liang Yung C.
Published: July 2009

It was discovered that the dielectric constant of the electrodes substantially determines the photovoltaic output in (Pb0.97La0.03)(Zr0.52Ti0.48)O3 ferroelectric thin films. With the screening charges distributed extensively away from the electrode interfaces, the use of the electrodes with a high dielectric constant gives rise to dramatically enhanced magnitude of photocurrent in photovoltaic thin films, and extremely high photovoltaic efficiency is theoretically predicted to be possible in ferroelectric ultrathin films or nanostructures.
Deviations from a simple Debye relaxation in aqueous solutions of differently flexible polyions induced by polymer concentration
Authors: Cametti C. , Sennato S. , Truzzolillo D.
Published: July 2009

The electrical conductivity of aqueous solutions of differently flexible polymers has been measured in the frequency range from 1 MHz to 2 GHz. This note evidences how the shape parameter α of the conductivity relaxation associated with the orientational polarization of the aqueous phase depends on the polymer concentration and, moreover, reflects the different concentration regimes of the polymer solution (dilute, semidilute entangled and nonentangled, and concentrated regimes). The relevance of this dependence, as far as the microscopic environment of water molecules is concerned, is briefly discussed.
Bulk and Interface effects on voltage linearity of ZrO2–SiO2 multilayered metal-insulator-metal capacitors for analog mixed-signal applications
Authors: Park S. D. , Park C. , Gilmer D. C. , Park H. K. , Kang C. Y. , Lim K. Y. , Burham C. , Barnett J. , Kirsch P. D. , Tseng H. H. , Jammy R. , Yeom G. Y.
Published: July 2009

Quadratic voltage coefficient of capacitance (VCC) for ZrO2–SiO2 multilayered dielectric metal-insulator-metal capacitors depends strongly on the stacking sequence of the layered dielectrics. The quadratic VCC of an optimized SiO2/ZrO2/SiO2 stack and ZrO2/SiO2/ZrO2 stack were +42 and −1094 ppm/V2, respectively, despite the same total SiO2 and ZrO2 dielectric thickness in the stack. The observed difference in quadratic VCC depending on dielectric stacking sequence is explained by taking into account both the interface and bulk dielectric responses to the applied voltage.
Transmission electron microscopy and scanning transmission electron microscopy study on B-site cation ordered structures in a (1−x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 single crystal
Authors: Sato Yukio , Mizoguchi Teruyasu , Shibata Naoya , Moriwake Hiroki , Hirayama Tsukasa , Ikuhara Yuichi
Published: July 2009

Transmission electron microscopy and scanning transmission electron microscopy were performed to investigate B-site cation-ordered structures in a (1−x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 (x∼0.30) single crystal. Selected-area diffraction patterns showed presence of F-spots corresponding to 1:1 order. Besides, the F-spots were elongated to be “X”-like in shape. Transmission electron microscopy dark-field images revealed that size of ordered domains was about a few nanometers, and they were dispersed within disordered matrix. Scanning transmission electron microscopy indicated the presence of 1:1 ordered domains. Presence of 1:2 ordered structures was also indicated. These are consistent with features of the selected-area diffraction patterns.
Pseudoelasticity of Cu–Zr nanowires via stress-induced martensitic phase transformations
Authors: Cheng Q. , Wu H. A. , Wang Y. , Wang X. X.
Published: July 2009

Atomistic simulations were performed to investigate the pseudoelastic effects induced by martensitic phase transformation from body-centered cubic (B2) to body-centered tetragonal (BCT) lattice in Cu–Zr nanowires. The phase transformation occurs through nucleation and propagation of {100} twin boundary, which differs from the {101} twin boundary for B2 Ni–Al nanowires. During unloading, extension strain up to 45% can be fully recovered through inverse phase transformation. The BCT lattice has also been verified to be metastable for Cu–Zr nanowires with an energy analysis along the epitaxial Bain path. Our work implies Cu–Zr nanowires may be excellent functional components for nanoelectromechanical systems.
Spatiotemporal intermittency and chaotic saddles in the regularized long-wave equation
Authors: Rempel Erico L. , Miranda Rodrigo A. , Chian Abraham C.-L.
Published: July 2009

Transition to intermittent spatiotemporal chaos is studied in the regularized long-wave equation, a nonlinear model of shallow water waves. A mechanism for the onset of on-off spatiotemporal intermittency is explored. In this mechanism, the coupling of two chaotic saddles triggers random switching between phases of laminar and bursty behaviors. The average time between bursts as a function of the control parameter follows a power law typical of crisis transitions in chaotic systems. The degree of spatiotemporal disorder in the observed fluid patterns is quantified by means of the time-averaged spectral entropy for both chaotic attractors and chaotic saddles. The implications of these results to other fluid systems are discussed.
Employing two distinct photonic crystal resonances to improve fluorescence enhancement
Authors: Mathias Patrick C. , Wu Hsin-Yu , Cunningham Brian T.
Published: July 2009

Surface-bound fluorescence assays such as microarrays have emerged as a prominent technology in current life sciences research and are currently performed on optically passive substrates such as glass microscope slides. We present an alternative approach using photonic crystal substrates exhibiting resonant reflections. In this work, we design and fabricate a photonic crystal with a TM-polarized resonance at the cyanine-5 excitation wavelength and a TE-polarized resonance spectrally overlapping this fluorophore’s emission spectrum. The former resonance increases the excitation of the fluorophore through enhanced electric field intensities, while the latter resonance redirects a proportion of emitted light toward the detection instrumentation. Spots of cyanine-5 conjugated streptavidin on the photonic crystal demonstrate a 60-fold increase in fluorescence intensity and a 42-fold increase in signal-to-noise ratio relative to a glass slide.
Mechanism of compositional modulations in epitaxial InAlN films grown by molecular beam epitaxy
Authors: Sahonta S.-L. , Dimitrakopulos G. P. , Kehagias Th. , Kioseoglou J. , Adikimenakis A. , Iliopoulos E. , Georgakilas A. , Kirmse H. , Neumann W. , Komninou Ph.
Published: July 2009

A mechanism for compositional modulations in InxAl1−xN films is described which considers growth kinetics during molecular beam epitaxy. InAlN crystalline films with various indium contents, grown on GaN or AlN buffer layers to create a variation in lattice mismatch conditions, were studied by transmission electron microscopy. Films comprise of columnar domains which are observed regardless of mismatch, with increasing indium concentration toward domain edges. We propose that indium is incorporated preferentially between adjacent dynamical InAlN platelets, owing to tensile strain generated upon platelet coalescence. The resulting In-rich boundaries are potential minima for further indium adatoms, creating a permanent indium composition gradient.
Increased fraction of weakened hydrogen bonds of water in aerosol OT reverse micelles
Authors: Waluyo Iradwikanari , Nordlund Dennis , Bergmann Uwe , Pettersson Lars G. M. , Nilsson Anders
Published: July 2009

Water in aerosol OT reverse micelles has been extensively studied as a model system for nanoconfined water. Results from previous vibrational studies suggest that water confined this way has slower dynamics compared to bulk water; however, the effects on the hydrogen bonding network are unclear. From our study of the structure of water hydrogen bonding using x-ray Raman spectroscopy, we found an increased fraction of weakened hydrogen bonds upon confinement, similar to the effect seen in temperature increase and NaCl solvation, as evidenced by the changes in specific spectral features.
Discharge ignition characteristics of pulsed radio-frequency glow discharges in atmospheric helium
Authors: Shi Jianjun , Cai Yeqing , Zhang Jie , Ding Ke , Zhang Jing
Published: July 2009

An experimental study of radio-frequency (15 MHz) glow discharges in atmospheric helium modulated by pulses with repetition frequency of 500 kHz and duty cycle of 6% and 8% is presented in this paper. In each discharge burst, the discharge is restricted to operate in ignition phase with duration of one or two radio-frequency cycles. The ignition characteristics in terms of spatial-temporal evolution of discharge interelectrode structure and optical emission intensity are investigated by time resolved imaging. Optical emission intensities at lines of 706 and 777 nm are used to capture clearly the temporal evolution of energetic electrons and active specie of atom oxygen generated in discharge.
DNA-triggered innate immune responses are propagated by gap junction communication
Authors: Patel Suraj J. , King Kevin R. , Casali Monica , Yarmush Martin L.
Published: July 2009

Cells respond to infection by sensing pathogens and communicating danger signals to noninfected neighbors; however, little is known about this complex spatiotemporal process. Here we show that activation of the innate immune system by double-stranded DNA (dsDNA) triggers intercellular communication through a gap junction-dependent signaling pathway, recruiting colonies of cells to collectively secrete antiviral and inflammatory cytokines for the propagation of danger signals across the tissue at large. By using live-cell imaging of a stable IRF3-sensitive GFP reporter, we demonstrate that dsDNA sensing leads to multicellular colonies of IRF3-activated cells that express the majority of secreted cytokines, including IFNβ and TNFα. Inhibiting gap junctions decreases dsDNA-induced IRF3 activation, cytokine production, and the resulting tissue-wide antiviral state, indicating that this immune response propagation pathway lies upstream of the paracrine action of secreted cytokines and may represent a host-derived mechanism for evading viral antiinterferon strategies.
High diversity of fungi in air particulate matter
Authors: Fröhlich-Nowoisky Janine , Pickersgill Daniel A. , Després Viviane R. , Pöschl Ulrich
Published: July 2009

Fungal spores can account for large proportions of air particulate matter, and they may potentially influence the hydrological cycle and climate as nuclei for water droplets and ice crystals in clouds, fog, and precipitation. Moreover, some fungi are major pathogens and allergens. The diversity of airborne fungi is, however, not well-known. By DNA analysis we found pronounced differences in the relative abundance and seasonal cycles of various groups of fungi in coarse and fine particulate matter, with more plant pathogens in the coarse fraction and more human pathogens and allergens in the respirable fine particle fraction (<3 μm). Moreover, the ratio of
Basidiomycota
to
Ascomycota
was found to be much higher than previously assumed, which might also apply to the biosphere.
Fibroblast growth factor–2 regulates the stability of nuclear bodies
Authors: Bruns Alexander-Francisco , van Bergeijk Jeroen , Lorbeer Christina , Nölle Anna , Jungnickel Julia , Grothe Claudia , Claus Peter
Published: July 2009

Nuclear bodies are distinct subnuclear structures. The survival of motoneuron (SMN) gene is mutated or deleted in patients with the neurodegenerative disease spinal muscular atrophy (SMA). The gene product SMN is a marker protein for one class of nuclear bodies denoted as nuclear gems. SMN has also been found in Cajal bodies, which co-localize with gems in many cell types. Interestingly, SMA patients display a reduced number of gems. Little is known about the regulation of nuclear body formation and stabilization. We have previously shown that a nuclear isoform of the fibroblast growth factor–2 (FGF-2
23
) binds directly to SMN. In this study, we analyzed the consequences of FGF-2
23
binding to SMN with regard to nuclear body formation. On a molecular level, we showed that FGF-2
23
competed with Gemin2 (a component of the SMN complex that is necessary for gem stabilization) for binding to SMN. Down-regulation of Gemin2 by siRNA caused destabilization of SMN-positive nuclear bodies. This process is reflected in both cellular and
in vivo
systems by a negative regulatory function of FGF-2 in nuclear body formation: in HEK293 cells, FGF-2
23
decreased the number of SMN-positive nuclear bodies. The same effect could be observed in motoneurons of FGF-2 transgenic mice. This study demonstrates the functional role of a growth factor in the regulation of structural entities of the nucleus.
Inactivating germ-line and somatic mutations in polypeptide
N
-acetylgalactosaminyltransferase 12 in human colon cancers
Authors: Guda Kishore , Moinova Helen , He Jian , Jamison Oliver , Ravi Lakshmeswari , Natale Leanna , Lutterbaugh James , Lawrence Earl , Lewis Susan , Willson James K. V. , Lowe John B. , Wiesner Georgia L. , Parmigiani Giovanni , Barnholtz-Sloan Jill , Dawson Dawn W. , Velculescu Victor E. , Kinzler Kenneth W. , Papadopoulos Nikolas , Vogelstein Bert , Willis Joseph , Gerken Thomas A. , Markowitz Sanford D.
Published: July 2009

Aberrant glycosylation is a pathological alteration that is widespread in colon cancer, and usually accompanies the onset and progression of the disease. To date, the molecular mechanisms underlying aberrant glycosylation remain largely unknown. In this study, we identify somatic and germ-line mutations in the gene encoding for polypeptide
N
-acetylgalactosaminyltransferase 12 (
GALNT12
) in individuals with colon cancer. Biochemical analyses demonstrate that each of the 8
GALNT12
mutations identified inactivates the normal function of the GALNT enzyme in initiating mucin type O-linked protein glycosylation. Two of these inactivating
GALNT12
mutations were identified as acquired somatic mutations in a set of 30 microsatellite stable colon tumors. Relative to background gene mutation rates, finding these somatic
GALNT12
mutations was statistically significant at
P
< 0.001. Six additional inactivating
GALNT12
mutations were detected as germ-line changes carried by patients with colon cancer; however, no inactivating variants were detected among cancer-free controls (
P
= 0.005). Notably, in 3 of the 6 individuals harboring inactivating germ-line
GALNT12
mutations, both a colon cancer and a second independent epithelial cancer had developed. These findings suggest that genetic defects in the O-glycosylation pathway in part underlie aberrant glycosylation in colon cancers, and they contribute to the development of a subset of these malignancies.
Transcriptome of embryonic and neonatal mouse cortex by high-throughput RNA sequencing
Authors: Han Xinwei , Wu Xia , Chung Wen-Yu , Li Tao , Nekrutenko Anton , Altman Naomi S. , Chen Gong , Ma Hong
Published: July 2009

Brain structure and function experience dramatic changes from embryonic to postnatal development. Microarray analyses have detected differential gene expression at different stages and in disease models, but gene expression information during early brain development is limited. We have generated >27 million reads to identify mRNAs from the mouse cortex for >16,000 genes at either embryonic day 18 (E18) or postnatal day 7 (P7), a period of significant synaptogenesis for neural circuit formation. In addition, we devised strategies to detect alternative splice forms and uncovered more splice variants. We observed differential expression of 3,758 genes between the 2 stages, many with known functions or predicted to be important for neural development. Neurogenesis-related genes, such as those encoding Sox4, Sox11, and zinc-finger proteins, were more highly expressed at E18 than at P7. In contrast, the genes encoding synaptic proteins such as synaptotagmin, complexin 2, and syntaxin were up-regulated from E18 to P7. We also found that several neurological disorder-related genes were highly expressed at E18. Our transcriptome analysis may serve as a blueprint for gene expression pattern and provide functional clues of previously unknown genes and disease-related genes during early brain development.
Heterozygosity for a Bub1 mutation causes female-specific germ cell aneuploidy in mice
Authors: Leland Shawn , Nagarajan Prabakaran , Polyzos Aris , Thomas Sharon , Samaan George , Donnell Robert , Marchetti Francesco , Venkatachalam Sundaresan
Published: July 2009

Aneuploidy, the most common chromosomal abnormality at birth and the main ascertained cause of pregnancy loss in humans, originates primarily from chromosome segregation errors during oogenesis. Here, we report that heterozygosity for a mutation in the mitotic checkpoint kinase gene,
Bub1
, induces aneuploidy in female germ cells of mice and that the effect increases with advancing maternal age. Analysis of Bub1 heterozygous oocytes showed that aneuploidy occurred primarily during the first meiotic division and involved premature sister chromatid separation. Furthermore, aneuploidy was inherited in zygotes and resulted in the loss of embryos after implantation. The incidence of aneuploidy in zygotes was sufficient to explain the reduced litter size in matings with Bub1 heterozygous females. No effects were seen in germ cells from heterozygous males. These findings show that Bub1 dysfunction is linked to inherited aneuploidy in female germ cells and may contribute to the maternal age-related increase in aneuploidy and pregnancy loss.
Host-derived glucose and its transporter in the obligate intracellular pathogen
Toxoplasma gondii
are dispensable by glutaminolysis
Authors: Blume Martin , Rodriguez-Contreras Dayana , Landfear Scott , Fleige Tobias , Soldati-Favre Dominique , Lucius Richard , Gupta Nishith
Published: July 2009

Toxoplasma gondii
, as an obligate intracellular and promiscuous pathogen of mammalian cells, utilizes host sugars for energy and to generate glycoconjugates that are important to its survival and virulence. Here, we report that
T. gondii
glucose transporter (TgGT1) is proficient in transporting mannose, galactose, and fructose besides glucose, and serves as a major hexose transporter at its plasma membrane.
Toxoplasma
harbors 3 additional putative sugar transporters (TgST1–3), of which TgST2 is expressed at its surface, whereas TgST1 and TgST3 are intracellular. Surprisingly, TgGT1 and TgST2 are nonessential to the parasite as their ablations inflict only a 30% or no defect in its intracellular growth, respectively. Indeed,
Toxoplasma
can also tolerate the deletion of both genes while incurring no further growth phenotype. Unlike Δ
tgst2
, the modest impairment in Δ
tggt1
and Δ
tggt1
/Δ
tgst2
mutants is because of a minor delay in their intracellular replication, which is a direct consequence of the abolished import of glucose. The Δ
tggt1
displays an attenuated motility in defined minimal media that is rescued by glutamine. TgGT1-complemented parasites show an entirely restored growth, motility, and sugar import. The lack of exogenous glucose in Δ
tggt1
culture fails to accentuate its intrinsic growth defect and prompts it to procure glutamine to sustain its metabolism. Unexpectedly, in vivo virulence of Δ
tggt1
in mice remains unaffected. Taken together, our data demonstrate that glucose is nonessential for
T. gondii
tachyzoites, underscore glutamine is a complement substrate, and provide a basis for understanding the adaptation of
T. gondii
to diverse host cells.
Cell type-dependent proapoptotic role of Bcl2L12 revealed by a mutation concomitant with the disruption of the juxtaposed
Irf3
gene
Authors: Nakajima Akira , Nishimura Keishiro , Nakaima Yukana , Oh Tomohiko , Noguchi Shigeru , Taniguchi Tadatsugu , Tamura Tomohiko
Published: July 2009

The generation of mice lacking the expression of the IRF3 transcription factor (
Irf3
−/−
mice) has revealed its crucial role in the activation of the type I IFN response. The
Bcl2l12
gene, encoding Bcl2L12 protein structurally related to the Bcl-2 family, was found to almost overlap with the
Irf3
gene, and the null mutation previously introduced into the
Irf3
allele resulted in the functional inactivation of the
Bcl2l12
gene; therefore, the mice are correctly termed
Irf3
−/−
Bcl2l12
−/−
mice. Embryonic fibroblasts from
Irf3
−/−
Bcl2l12
−/−
mice (
Irf3
−/−
Bcl2l12
−/−
MEFs) showed resistance to DNA damage-induced apoptosis, accompanied by impaired caspase cleavage. This apoptotic defect in
Irf3
−/−
Bcl2l12
−/−
MEFs was rescued by the ectopic expression of Bcl2L12, but not IRF3. The Bcl2L12-mediated apoptotic response depended on the cell type and extracellular stimulus. In contrast, the previously reported defect in the induction of type I IFN genes by nucleic acids in
Irf3
−/−
Bcl2l12
−/−
MEFs was rescued by expressing IRF3, but not Bcl2L12. Thus, our present study revealed, on the one hand, a cell type-dependent proapoptotic function of Bcl2L12 and, on the other hand, confirmed the essential role of IRF3 in type I IFN response.
Angular momentum studies with NBI modulation in JET
Authors: Tardini G. , Ferreira J. , Mantica P. , Peeters A.G. , Tala T. , Zastrow K.D. , Brix M. , Giroud C. , Pereverzev G.V.
Published: July 2009

In this work we apply the neutral beam modulation technique to a set of JET discharges in order to obtain information on the radial transport of the toroidal angular momentum. This perturbative technique allows one to separate possible pinch terms from the momentum diffusivity, otherwise impossible to decouple with a steady-state momentum balance analysis alone. In this paper a model based on the ion temperature gradient turbulence, which consists of a constant and uniform Prandtl number of the order unity combined with an inward Coriolis pinch term predicted by the gyro-kinetic theory, is validated against data from the JET experiment. The machine size and the good space and time resolution of the charge exchange system make JET particularly suitable for this study. The experimental data are matched with good accuracy, both the steady-state and the transient propagation of the momentum perturbation, choosing a Prandtl number slightly above one, provided the Coriolis pinch is included. Sensitivity studies assess the accuracy range of our predictive modelling.
Validating a quasi-linear transport model versus nonlinear simulations
Authors: Casati A. , Bourdelle C. , Garbet X. , Imbeaux F. , Candy J. , Clairet F. , Dif-Pradalier G. , Falchetto G. , Gerbaud T. , Grandgirard V. , Gürcan Ö.D. , Hennequin P. , Kinsey J. , Ottaviani M. , Sabot R. , Sarazin Y. , Vermare L. , Waltz R.E.
Published: July 2009

In order to gain reliable predictions on turbulent fluxes in tokamak plasmas, physics based transport models are required. Nonlinear gyrokinetic electromagnetic simulations for all species are still too costly in terms of computing time. On the other hand, interestingly, the quasi-linear approximation seems to retain the relevant physics for fairly reproducing both experimental results and nonlinear gyrokinetic simulations. Quasi-linear fluxes are made of two parts: (1) the quasi-linear response of the transported quantities and (2) the saturated fluctuating electrostatic potential. The first one is shown to follow well nonlinear numerical predictions; the second one is based on both nonlinear simulations and turbulence measurements. The resulting quasi-linear fluxes computed by QuaLiKiz (Bourdelle et al 2007 Phys. Plasmas
14 112501) are shown to agree with the nonlinear predictions when varying various dimensionless parameters, such as the temperature gradients, the ion to electron temperature ratio, the dimensionless collisionality, the effective charge and ranging from ion temperature gradient to trapped electron modes turbulence.
MHD induced fast-ion losses on ASDEX Upgrade
Authors: García-Muñoz M. , Fahrbach H.-U. , Pinches S.D. , Bobkov V. , Brüdgam M. , Gobbin M. , Günter S. , Igochine V. , Lauber Ph. , Mantsinen M.J. , Maraschek M. , Marrelli L. , Martin P. , Piovesan P. , Poli E. , Sassenberg K. , Tardini G. , Zohm H.
Published: July 2009

A detailed knowledge of the interplay between MHD instabilities and energetic particles has been gained from direct measurements of fast-ion losses (FILs). Time-resolved energy and pitch angle measurements of FIL caused by neoclassical tearing modes (NTMs) and toroidicity-induced Alfven eigenmodes (TAEs) have been obtained using a scintillator based FIL detector. The study of FIL due to TAEs has revealed the existence of a new core-localized MHD fluctuation, the Sierpes mode. The Sierpes mode is a non-pure Alfvenic fluctuation which appears in the acoustic branch, dominating the transport of fast-ions in ICRF heated discharges. The internal structure of both TAEs and Sierpes mode has been reconstructed by means of highly resolved multichord soft x-ray measurements. A spatial overlapping of their eigenfunctions leads to a FIL coupling, showing the strong influence that a core-localized fast-ion driven MHD instability may have on the fast-ion transport. We have identified the FIL mechanisms due to NTMs as well as due to TAEs. Drift islands formed by fast-ions in particle phase space are responsible for the loss of NBI fast-ions due to NTMs. In ICRF heated plasmas, a resonance condition fulfilled by the characteristic trapped fast-ion orbit frequencies leads to a phase matching between fast-ion orbit and NTM or TAE magnetic fluctuation. The banana tips of a resonant trapped fast-ion bounce radially due to an E × B drift in the TAE case. The NTM radial bounce of the fast-ion banana tips is caused by the radial component of the perturbed magnetic field lines.
Experimental studies of ITER demonstration discharges
Authors: Sips A.C.C. , Casper T.A. , Doyle E.J. , Giruzzi G. , Gribov Y. , Hobirk J. , Hogeweij G.M.D. , Horton L.D. , Hubbard A.E. , Hutchinson I. , Ide S. , Isayama A. , Imbeaux F. , Jackson G.L. , Kamada Y. , Kessel C. , Kochl F. , Lomas P. , Litaudon X. , Luce T.C. , Marmar E. , Mattei M. , Nunes I. , Oyama N. , Parail V. , Portone A. , Saibene G. , Sartori R. , Stober J.K. , Suzuki T. , Wolfe S.M.
Published: July 2009

Key parts of the ITER scenarios are determined by the capability of the proposed poloidal field (PF) coil set. They include the plasma breakdown at low loop voltage, the current rise phase, the performance during the flat top (FT) phase and a ramp down of the plasma. The ITER discharge evolution has been verified in dedicated experiments. New data are obtained from C-Mod, ASDEX Upgrade, DIII-D, JT-60U and JET. Results show that breakdown for E
axis < 0.23–0.33 V m−1 is possible unassisted (ohmic) for large devices like JET and attainable in devices with a capability of using ECRH assist. For the current ramp up, good control of the plasma inductance is obtained using a full bore plasma shape with early X-point formation. This allows optimization of the flux usage from the PF set. Additional heating keeps l
i(3) < 0.85 during the ramp up to q
95 = 3. A rise phase with an H-mode transition is capable of achieving l
i(3) < 0.7 at the start of the FT. Operation of the H-mode reference scenario at q
95 ∼ 3 and the hybrid scenario at q
95 = 4–4.5 during the FT phase is documented, providing data for the l
i (3) evolution after the H-mode transition and the l
i (3) evolution after a back-transition to L-mode. During the ITER ramp down it is important to remain diverted and to reduce the elongation. The inductance could be kept ⩽1.2 during the first half of the current decay, using a slow I
p ramp down, but still consuming flux from the transformer. Alternatively, the discharges can be kept in H-mode during most of the ramp down, requiring significant amounts of additional heating.
First dynamic magnetic configuration scans in ECRH plasmas of the TJ-II Heliac
Authors: López-Bruna D. , Romero J.A. , Jiménez-Gómez R. , Pedrosa M.A. , Ochando M. , Estrada T. , López-Fraguas A. , Medina F. , Herranz J. , Kalhoff T. , Ascasíbar E. , de la Peña A. , Lapayese F. , Alonso J.
Published: July 2009

The configurational flexibility of the TJ-II Heliac has been upgraded with the commissioning of a mode of operation that allows changing the magnetic configuration dynamically: the currents feeding the different coil sets can be ramped during the discharge, which allows for, for example, moving up or down the offset of the rotational transform profile. The first discharges in this operation mode have been designed to investigate the effect of low order rational values of the rotational transform,
, in low magnetic shear plasmas created and sustained with electron cyclotron resonance heating. The main magnetic resonances (8/5 and 5/3 in this work) do not deteriorate confinement except occasionally in a short, transient manner that is accompanied by a magnetic event with a clear frequency splitting.
Ganoderma lucidumProtects Dopaminergic Neuron Degeneration through Inhibition of Microglial Activation
Authors: Zhang Ruiping , Xu Shengli , Cai Yanning , Zhou Ming , Zuo Xiaohong , Chan Piu
Published: July 2009

Abundant evidence has suggested that neuroinflammation participates in the pathogenesis of Parkinson′s disease (PD). The emerging evidence has supported that microglia may play key roles in the progressive neurodegeneration in PD and might be a promising therapeutic target.Ganoderma lucidum(GL), a traditional Chinese medicinal herb, has been shown potential neuroprotective effects in our clinical trials that make us to speculate that it might possess potent anti‐inflammatory and immunomodulating properties. To test this hypothesis, we investigated the potential neuroprotective effect of GL and possible underlying mechanism of action through protecting microglial activation using co‐cultures of dopaminergic neurons and microglia. The microglia is activated by LPS and MPP+‐treated MES 23.5 cell membranes. Meanwhile, GL extracts significantly prevent the production of microglia‐derived proinflammatory and cytotoxic factors [nitric oxide, tumor necrosis factor‐α(TNF‐α), interlukin 1β(IL‐1β)] in a dose‐dependent manner and down‐regulate the TNF‐αand IL‐1βexpressions on mRNA level as well. In conclusion, our results support that GL may be a promising agent for the treatment of PD through anti‐inflammation.
[Retracted] Modulation of Signal Proteins: A Plausible Mechanism to Explain How a Potentized Drug Secale Cor 30C Diluted beyond Avogadro′s Limit Combats Skin Papilloma in Mice
Authors: Khuda-Bukhsh Anisur Rahman , Bhattacharyya Soumya Sundar , Paul Saili , Dutta Suman , Boujedaini Naoual , Belon Philippe
Published: July 2009

In homeopathy, ability of ultra‐high diluted drugs at or above potency 12C (diluted beyond Avogadro′s limit) in ameliorating/curing various diseases is often questioned, particularly because the mechanism of action is not precisely known. We tested the hypothesis if suitable modulations of signal proteins could be one of the possible pathways of action of a highly diluted homeopathic drug, Secale cornutum 30C (diluted 1060 times; Sec cor 30). It could successfully combat DMBA + croton oil‐induced skin papilloma in mice as evidenced by histological, cytogenetical, immunofluorescence, ELISA and immunoblot findings. Critical analysis of several signal proteins like AhR, PCNA, Akt, Bcl‐2, Bcl‐xL, NF‐κB and IL‐6 and of pro‐apoptotic proteins like cytochrome c, Bax, Bad, Apaf, caspase‐3 and ‐9 revealed that Sec cor 30 suitably modulated their expression levels along with amelioration of skin papilloma. FACS data also suggested an increase of cell population at S and G2 phases and decrease in sub‐G1 and G1 phages in carcinogen‐treated drug‐unfed mice, but these were found to be near normal in the Sec cor 30‐fed mice. There was reduction in genotoxic and DNA damages in bone marrow cells of Sec Cor 30‐fed mice, as revealed from cytogenetic and Comet assays. Changes in histological features of skin papilloma were noted. Immunofluorescence studies of AhR and PCNA also suggested reduced expression of these proteins in Sec cor 30‐fed mice, thereby showing its anti‐cancer potentials against skin papilloma. Furthermore, this study also supports the hypothesis that potentized homeopathic drugs act at gene regulatory level.
Suppression of Heregulin‐β1/HER2‐Modulated Invasive and Aggressive Phenotype of Breast Carcinoma by Pterostilbene via Inhibition of Matrix Metalloproteinase‐9, p38 Kinase Cascade and Akt Activation
Authors: Pan Min-Hsiung , Lin Ying-Ting , Lin Chih-Li , Wei Chi-Shiang , Ho Chi-Tang , Chen Wei-Jen
Published: July 2009

Invasive breast cancer is the major cause of death among females and its incidence is closely linked to HER2 (human epidermal growth factor receptor 2) overexpression. Pterostilbene, a natural analog of resveratrol, exerts its cancer chemopreventive activity similar to resveratrol by inhibiting cancer cell proliferation and inducing apoptosis. However, the anti‐invasive effect of pterostilbene on HER2‐bearing breast cancer has not been evaluated. Here, we used heregulin‐β1 (HRG‐β1), a ligand for HER3, to transactivate HER2 signaling. We found that pterostilbene was able to suppress HRG‐β1‐mediated cell invasion, motility and cell transformation of MCF‐7 human breast carcinoma through down‐regulation of matrix metalloproteinase‐9 (MMP‐9) activity and growth inhibition. In parallel, pterostilbene also inhibited protein and mRNA expression of MMP‐9 driven by HRG‐β1, suggesting that pterostilbene decreased HRG‐β1‐mediated MMP‐9 induction via transcriptional regulation. Examining the signaling pathways responsible for HRG‐β1‐associated MMP‐9 induction and growth inhibition, we observed that pterostilbene, as well as SB203580 (p38 kinase inhibitor), can abolish the phosphorylation of p38 mitogen‐activated protein kinase (p38 kinase), a downstream HRG‐β1‐responsive kinase responsible for MMP‐9 induction. In addition, HRG‐β1‐driven Akt phosphorylation required for cell proliferation was also suppressed by pterostilbene. Taken together, our present results suggest that pterostilbene may serve as a chemopreventive agent to inhibit HRG‐β1/HER2‐mediated aggressive and invasive phenotype of breast carcinoma through down‐regulation of MMP‐9, p38 kinase and Akt activation.
Liberty Hyde Bailey, the Country Life Commission and the formalization of farm credit in the USA
Authors: Turvey Calum G.
Published: July 2009

Purpose

This paper reviews the life of Liberty Hyde Bailey and highlights his contributions to the structure of US farm credit 100 years after the Country Life Commission.

Design/methodology/approach

This paper is a qualitative historical review.

Findings

The paper provides a chronology of life events that led Liberty Hyde Bailey to evolve from botanist/horticulturalists to one of America's most vocal proponents of agricultural and country life, culminating in the recommendation in 1909 that rural credit in the USA be developed along the lines of cooperative principles.

Research limitations/implications

The biography is limited to issues of social science, culminating in 1915.

Practical implications

The paper offers a historical perspective on conditions in agriculture in the early twentieth century and provides insights into how the present system of rural credit in the USA evolved.

Originality/value

This paper provides a historical perspective on US rural credit that is of use to students of rural credit in the USA while providing insights to students and scholars outside of the USA with a perspective on the evolution of US credit reform and cooperative credit.
The impact of board of director characteristics on Farm Credit Association performance
Authors: Gunderson Michael , Gloy Brent , Rodgers Chris
Published: July 2009

Purpose

The purpose of this paper is to identify how board size and board member compensation impact the operating performance of Farm Credit Associations. Cooperatives are a unique business structure that might not have profit maximization as a goal. Thus measures of performance other than return on equity are used to establish the link.

Design/methodology/approach

The paper uses regression to explain the relationship between board characteristics and performance.

Findings

The results of the models of return on assets and equity indicated that board size and compensation explain little of the variability in performance in these profitability measures. The results of the models of operating efficiencies explained a greater proportion of the variability in the operating efficiency and operating expenses‐to‐average assets ratios. In both models the relationship exhibited diminishing returns to board size and per member compensation.

Research limitations/implications

The data are based on just one year of performance, limiting the generalizability of the results.

Practical implications

The paper includes implications for the size of boards of directors and director compensation.

Originality/value

This paper fulfils an identified need to study the impacts of boards of directors for cooperatives.
Factors affecting financial performance of new and beginning farmers
Authors: Mishra Ashok , Wilson Christine , Williams Robert
Published: July 2009

Purpose

The purpose of this paper is to investigate the factors (farm, operator and household characteristics, along with farm type and regional location of the farm) affecting financial performance of new and beginning farmers and ranchers.

Design/methodology/approach

Returns on assets (ROA), a measure of financial performance widely used in the farm management literature, is the ratio of net farm income plus interest payment to total assets. This measure has been used by Gloy and LaDue and Gloy et al. to measure financial performance of farmers in New York. ROA is hypothesized to be a function of operator/farm characteristics and management strategies used to manage the farm. The independent variables hypothesized to affect the farm's financial performance encompass the following three areas: farm operator characteristics, farm characteristics such as production and marketing efficiency measures, and management strategies. All standard errors were adjusted for heteroscedasticity using the Huber–White sandwich robust variance estimator based on algorithms contained in STATA.

Findings

Results from this study show that although there is an inverted U‐shaped relationship between age of the operator and financial performance, management strategies such as increasing the number of decision makers, engaging in value‐added farming, and having a written business plan can lead to higher financial performance.

Originality/value

More than 50 percent of current farmers are likely to retire in the next five years. US farmers over age 55 control more than half the farmland, while the number of new farmers replacing them has fallen since the Farm Crisis period, 1982‐1987. Paralleling this shift in production, agriculture is in a decline in overall farm numbers. Concern in many states arises because the loss adversely affects the future of family farms, the farm economy and healthy rural communities. Additionally, the rapid decline in the entry of new and young farmers is an indication of rising barriers to entry, resulting in calls from within the farming community for public policy measures designed to aid new and beginning farmers.
Agricultural, recreational and urban influences on agricultural land prices
Authors: Guiling Pamela , Doye Damona
Published: July 2009

Purpose

This paper aims to determine the effects of agricultural, recreational and urban variables on Oklahoma land prices.

Design/methodology/approach

An econometric model is estimated using price of agricultural land parcels as the dependent variable and independent variables representing agricultural, recreational and urban uses. Recreational variables include county‐level recreational income from Agricultural Census data as well as deer harvest for each county. Urban variables are functions of population and income for each county. The agricultural variables include rainfall as well as crop returns for cropland and cattle prices for pasture.

Findings

Agricultural variables are the most important, followed by urban and then recreational variables. Transaction prices are higher than commonly used land‐value survey data. The major recreational variable is deer harvest, which is more important in small tracts. The value of pasture is now greater than cropland. Small tract sizes receive substantial premiums.

Research limitations/implications

Agriculture is still an important part of the Oklahoma economy, so the findings might differ in more densely populated states. As with most econometric models, there are possible biases due to errors in measurement or missing explanatory variables.

Practical implications

The paper provides information that could be used by those wanting to estimate land value or wanting to manage land to increase its value.

Originality/value

The paper differs from previous work in both variables considered and the data used. Also, most previous work has not as directly addressed the issue of the relative importance of agricultural, recreational and urban variables.