bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of informative metabolic responses using a minibioreactor: a small step change in the glucose supply rate creates a large metabolic response in Saccharomyces cerevisiae
Authors: Aboka Fredrick O. , van Winden Wouter A. , Reginald Mashego M. , van Gulik Walter M. , van de Berg Marco , Oudshoorn Arthur , Heijnen Joseph J.
Published: January 2012

In this study, a previously developed mini‐bioreactor, the Biocurve, was used to identify an informative stimulus–response experiment. The identified stimulus–response experiment was a modest 50% shift‐up in glucose uptake rate (qGLC) that unexpectedly resulted in a disproportionate transient metabolic response. The 50% shift‐up in qGLC in the Biocurve resulted in a near tripling of the online measured oxygen uptake (qO2) and carbon dioxide production (qCO2) rates, suggesting a considerable mobilization of glycogen and trehalose. The 50% shift‐up in qGLC was subsequently studied in detail in a conventional bioreactor (4 l working volume), which confirmed the results obtained with the Biocurve. Especially relevant is the observation that the 50% increase in glucose uptake rate led to a three‐fold increase in glycolytic flux, due to mobilization of storage materials. This explains the unexpected ethanol and acetate secretion after the shift‐up, in spite of the fact that after the shift‐up the qGLC was far less than the critical value. Moreover, these results show that the correct in vivo fluxes in glucose pulse experiments cannot be obtained from the uptake and secretion rates only. Instead, the storage fluxes must also be accurately quantified. Finally, we speculate on the possible role that the transient increase in dissolved CO2 immediately after the 50% shift‐up in qGLC could have played a part in triggering glycogen and trehalose mobilization. Copyright © 2012 John Wiley & Sons, Ltd.
Variation in seed germination of 86 subalpine forest species from the eastern Tibetan Plateau: phylogeny and life‐history correlates
Authors: Wang JuHong , Chen Wen , Baskin Carol C. , Baskin Jerry M. , Cui XianLiang , Zhang Yong , Qiang WeiYa , Du GuoZhen
Published: January 2012

We have examined the seed germination strategy of 86 subalpine woody species from the eastern part of the Tibetan Plateau and assessed correlations between seed germination and phylogeny, life‐history attributes, habitat, and altitude using stepwise analyses of variance (ANOVAs) and phylogenetically independent contrasts (PICs). A series of ANOVAs revealed that the total amount of variance in the arcsine‐transformed value of germination percentage among species could be accounted for by phylogeny (19.2%) and dispersal mode (14.3%) in seeds incubated in the light and by phylogeny (29.3%) and dispersal mode (11.0%) in those incubated in the dark. In addition, the total amount of variance in T50 (days to half of the final germination) can be accounted for by phylogeny (22.7%) and dispersal mode (17%) in seeds incubated in the light and by phylogeny (32.1%) and dispersal mode (9.9%) in those incubated in the dark. PICs indicated a significant correlation between germination percentage and dispersal mode and a positive correlation between T50 and seed mass, showing that wind‐dispersed seeds had higher germination percentages than both unassisted and vertebrate‐dispersed seeds and that small seeds germinated faster than large ones. We suggest that phylogeny and dispersal mode may constrain variation in seed germination across species and that the speed of germination and seed mass may co‐vary to adapt to a variable environment. Therefore, from an evolutionary perspective, seed germination might be the result of both selective pressures over long‐term ecological time and phylogenetic constraints over the long‐standing evolutionary history of the phylogenetic group.
Anti‐diabetic and anti‐obesity agent sodium tungstate enhances GCN pathway activation through Glc7p inhibition
Authors: Rodriguez-Hernandez C.J. , Guinovart J.J. , Murguia J.R.
Published: January 2012

Tungstate counteracts diabetes and obesity in animal models, but its molecular mechanisms remain elusive. Our Saccharomyces cerevisiae‐based approach has found that tungstate alleviated the growth defect induced by nutrient stress and enhanced the activation of the GCN pathway. Tungstate relieved the sensitivity to starvation of a gcn2‐507 yeast hypomorphic mutant, indicating that tungstate modulated the GCN pathway downstream of Gcn2p. Interestingly, tungstate inhibited Glc7p and PP1 phosphatase activity, both negative regulators of the GCN pathway in yeast and humans, respectively. Accordingly, overexpression of a dominant‐negative Glc7p mutant in yeast mimicked tungstate effects. Therefore tungstate alleviates nutrient stress in yeast by in vivo inhibition of Glc7p. These data uncover a potential role for tungstate in the treatment of PP1 and GCN related diseases.
BMI among Timorese aged ≥40 years
Authors: Ramke Jacqueline , Brian Garry
Published: January 2012

Objective

To determine the distribution and sociodemographic associations of BMI (kg/m2) among adults aged ≥40 years living in Timor-Leste.

Design

BMI was calculated for participants of a population-based cross-sectional survey.

Setting

Urban and rural Timor-Leste.

Subjects

Adults aged ≥40 years living in Timor-Leste.

Results

Of those enumerated, 2014 participated (89·5 %). Male gender, rural domicile, older age, illiteracy and source of household income were associated with BMI < 18·5 kg/m2 on multivariate analysis. Female gender, urban domicile and literacy were associated with BMI ≥25·0 and ≥30·0 kg/m2. Adjusting for gender, age and domicile, and extrapolating to those aged ≥40 years across Timor-Leste, 9·9 %, 36·0 %, 6·6 % and 0·8 % had BMI <16·0, <18·5, ≥25·0 and ≥30·0 kg/m2, respectively.

Conclusions

At this time, being ‘underweight’ or ‘severely thin’ is more prevalent in the Timorese adult population than being ‘overweight’ or ‘obese’.
THEHYAKUMANTŌ DARANIAND THE ORIGINS OF PRINTING IN EIGHTH-CENTURY JAPAN
Authors: Kornicki Peter
Published: January 2012

The origins of printing in East Asia have been the subject of lively debate over the last twenty years, and a constant point of reference has been the first recorded act of printing in Japan, which took place in the 760s. The term Hyakumantō Darani 百万塔陀羅尼 (hereafter HD) is commonly used in Japan to refer to this episode, and it denotes the Buddhist dhāraṇī or spells which are thought to have been printed in Nara and then inserted into wooden miniature pagodas, and which have for a century been regarded as the oldest printed texts in the world.1They were printed, so the evidence suggests, in the closing years of the reign of Shōtoku 稱德 (718–770, r. 764–770), who was the last woman on the Japanese throne for nearly one thousand years and who had had an earlier reign under the name Kōken 孝謙 (r. 749–758).2

In this article I shall first examine the evidence relating to the HD and the origins of printing, since the whole question has long been clouded by hypotheses masquerading as fact. Second, I shall explore the origins of the practice of producing miniature pagodas and its transmission to Japan. Third, I shall argue that the established views on the motivation for the HD are inadequate, and shall identify the factors that demand a new explanation, particularly the pagodas themselves. Finally, I turn to the ideological and political factors underlying these events and suggest a new explanation. This new explanation focuses on the politics of Shōtoku's situation and the connection with empress Wu (Wu Zetian 武則天; 624–705, r. 690–705), and it goes some way towards explaining why printing was not resorted to again in Japan for several centuries.
A modified surface energy balance algorithm for land (M‐SEBAL) based on a trapezoidal framework
Authors: Long Di , Singh Vijay P.
Published: January 2012

The surface energy balance algorithm for land (SEBAL) has been designed and widely used (and misused) worldwide to estimate evapotranspiration across varying spatial and temporal scales using satellite remote sensing over the past 15 yr. It is, however, beset by visual identification of a hot and cold pixel to determine the temperature difference (dT) between the surface and the lower atmosphere, which is assumed to be linearly correlated with surface radiative temperature (Trad) throughout a scene. To reduce ambiguity in flux estimation by SEBAL due to the subjectivity in extreme pixel selection, this study first demonstrates that SEBAL is of a rectangular framework of the contextual relationship between vegetation fraction (fc) and Trad, which can distort the spatial distribution of heat flux retrievals to varying degrees. End members of SEBAL were replaced by a trapezoidal framework of the fc‐Trad space in the modified surface energy balance algorithm for land (M‐SEBAL). The warm edge of the trapezoidal framework is determined by analytically deriving temperatures of the bare surface with the largest water stress and the fully vegetated surface with the largest water stress implicit in both energy balance and radiation budget equations. Areally averaged air temperature (Ta) across a study site is taken to be the cold edge of the trapezoidal framework. Coefficients of the linear relationship between dT and Trad can vary with fc but are assumed essentially invariant for the same fc or within the same fc class in M‐SEBAL. SEBAL and M‐SEBAL are applied to the soil moisture‐atmosphere coupling experiment (SMACEX) site in central Iowa, U.S. Results show that M‐SEBAL is capable of reproducing latent heat flux in terms of an overall root‐mean‐square difference of 41.1 W m−2 and mean absolute percentage difference of 8.9% with reference to eddy covariance tower‐based measurements for three landsat thematic mapper/enhanced thematic mapper plus imagery acquisition dates in 2002. The retrieval accuracy of SEBAL is generally lower than M‐SEBAL, depending largely on the selected extremes. Spatial distributions of heat flux retrievals from SEBAL are distorted to a certain degree due to its intrinsic rectangular framework.
The Flavonoid Fisetin Attenuates Postischemic Immune Cell Infiltration, Activation and Infarct Size after Transient Cerebral Middle Artery Occlusion in Mice
Authors: Gelderblom Mathias , Leypoldt Frank , Lewerenz Jan , Birkenmayer Gabriel , Orozco Denise , Ludewig Peter , Thundyil John , Arumugam Thiruma V , Gerloff Christian , Tolosa Eva , Maher Pamela , Magnus Tim
Published: January 2012

The development of the brain tissue damage in ischemic stroke is composed of an immediate component followed by an inflammatory response with secondary tissue damage after reperfusion. Fisetin, a flavonoid, has multiple biological effects, including neuroprotective and antiinflammatory properties. We analyzed the effects of fisetin on infarct size and the inflammatory response in a mouse model of stroke, temporary middle cerebral artery occlusion, and on the activation of immune cells, murine primary and N9 microglial and Raw264.7 macrophage cells and human macrophages, in an in vitro model of inflammatory immune cell activation by lipopolysaccharide (LPS). Fisetin not only protected brain tissue against ischemic reperfusion injury when given before ischemia but also when applied 3 hours after ischemia. Fisetin also prominently inhibited the infiltration of macrophages and dendritic cells into the ischemic hemisphere and suppressed the intracerebral immune cell activation as measured by intracellular tumor necrosis factor α (TNFα) production. Fisetin also inhibited LPS-induced TNFα production and neurotoxicity of macrophages and microglia in vitro by suppressing nuclear factor κB activation and JNK/Jun phosphorylation. Our findings strongly suggest that the fisetin-mediated inhibition of the inflammatory response after stroke is part of the mechanism through which fisetin is neuroprotective in cerebral ischemia.
The legacy of bio-molecules as a bio-fertilizer: Context of single cell fertilizer Isolation and partial characterization of an amylolytic bacterium
Authors: Sen Sribir , Banerjee Anwesha , Sanyal Sanghamitra
Published: January 2012

Repeated cultivation of crop plants is the reason for the depletion of nutrients in an agricultural land. Therefore, modern procedures of agriculture cascaded with the addition of organic and inorganic fertilizers, the use of insecticides and pesticides, the addition of proper water, etc. Various inorganic molecules are used as fertilizers. However, the use of organic manures is also in practice. They have many roles such as improving soil porosity, air holding capacity, water holding capacity, structure, texture, etc. Agricultural scientists suggest using organic molecules for many reasons. Bio-fertilizers of many kinds are used by farmers of all nations. However, these fertilizers are unable to cause tremendous effects on the growth and development of crop plants, even though these fertilizers have cumulative effects. The present work focuses on the use of bio-molecules as bio-fertilizer. To make these molecules, an amylolytic bacterium was isolated and partially identified based on microscopic observations and biochemical tests. The optimum pH, temperature, substrate concentration, etc. were studied. The optimum pH and temperature for the growth of the isolate were pH 7.0 and 37.0°C, respectively. However, the organism grows even in 60.0°C. The organism uses four commonly available natural substrates as carbon source. Among these, potato starch is the most conveniently utilized by the organism. The amy gene of the strain was cloned using a vector. It expressed a high amount of amylase (data is not shown). The recombinant organism was used to make bio-molecules. It was grown in the presence of various natural substrates and enzymatic activities, and other associated studies were also carried out. The experimental results obtained in this study showed that the recombinant organism can be utilized to make a huge amount of bio-molecules. It will be a unique fertilizer for future generations.
Rotationally resolved infrared spectroscopy of adamantane
Authors: Pirali O. , Boudon V. , Oomens J. , Vervloet M.
Published: January 2012

We present the first rotationally resolved spectra of adamantane (C10H16) applying gas-phase Fourier transform infrared (IR) absorption spectroscopy. High-resolution IR spectra are recorded in the 33–4500 cm−1range using as source of IR radiation both synchrotron radiation (at the AILES beamline of the SOLEIL synchrotron) as well as a classical globar. Adamantane is a spherical top molecule with tetrahedral symmetry (Td point group) and has no permanent dipole moment in its vibronic ground state. Of the 72 fundamental vibrational modes in adamantane, only 11 are IR active. Here we present rotationally resolved spectra for seven of them: ν30, ν28, ν27, ν26, ν25, ν24, and ν23. The typical rotational structure of spherical tops is observed and analyzed using the STDS software developed in the Dijon group, which provides the first accurate energy levels and rotational constants for seven fundamental modes. Rotational levels with quantum numbers as high as J = 107 have been identified and included in the fit leading to a typical standard deviation of about 10−3 cm−1.
Anderson localization in metamaterials with compositional disorder
Authors: Torres-Herrera E. J. , Izrailev F. M. , Makarov N. M.
Published: January 2012

We consider one-dimensional periodic-on-average bi-layered models with random perturbations in dielectric constants of both basic slabs composing the structure unit-cell. We show that when the thicknesses da and db of basic layers are essentially nonequal, da ≠ db, the localization length Lloc is described by the universal expression for two cases: (a) both layers are made from right-handed materials (the RH–RH model), (b) the a layers are of a right-handed material while the b layers are of a left-handed material (the RH–LH model). For these models the derived expression for Lloc includes all possible correlations between two disorders. However, when da = db the RH–LH model exhibits a highly nontrivial properties originated from inhomogeneous distribution of the phase of propagating wave, even in the case of white-noise disorder. We analytically show that in this case the localization length diverges in the conventional second order in perturbation parameters. Therefore, recently numerically discovered anomalies in Lloc are due to the next order of approximation. On the other hand, for the RH–RH model the general expression for Lloc remains valid for da = db as well.
Electronic states on the rough surface of a solid
Authors: Khankina S. I. , Yakovlenko V. M. , Yakovlenko I. V.
Published: January 2012

Surface electronic states at a periodically rough boundary have been obtained and studied. It is shown that there are two spectral regions of surface states separated by a forbidden band. The properties of the surface states in these regions are quite dissimilar. It is found that the action of surface electronic states gives rise to a subsurface inhomogeneous plasma layer, responsible for the peculiar features of polariton distribution and spatial dispersion of electrostatic vibration frequency. The related dispersion relations are derived. Some peculiarities of electronic state creation are considered for the where the periodic surface roughness is caused by the Rayleigh sound propagation.
Rainbow trapping of guided waves
Authors: Polanco Javier , Fitzgerald Rosa M. , Leskova Tamara A. , Maradudin Alexei A.
Published: January 2012

We study theoretically the propagation of a wave packet that is a superposition of three s-polarized guided waves with different frequencies in a planar waveguide consisting of a dielectric medium with a graded index of refraction, sandwiched between perfectly conducting walls. The electric field at each point within the waveguide is calculated, and it is shown that each of the constituent modes ceases to propagate at a specific distance along the waveguide that depends on its frequency and on the geometrical and material parameters defining the waveguide. This simple model displays the phenomenon of rainbow trapping of guided waves in an explicit fashion, without the use of a negative index metamaterial.
Collective excitations of electron gas on the nanotube surface in a magnetic field
Authors: Ermolaev A. M. , Rashba G. I. , Solyanik M. A.
Published: January 2012

The spectra of magnetoplasma waves, zero sound and spin waves in an electron gas on a surface of a nonferromagnetic nanotube in longitudinal magnetic field are considered. The initial spectrum of the electron energy is assumed to be parabolic, and the interelectron interaction is taken into account within the random-phase approximation. It is shown that in a magnetic field there is a shift of the frequency of an intersubband plasmon proportional to a magnetic flux through a cross-section of a tube. The frequency and the damping constant of magnetoplasma waves in a nondegenerate electron gas are calculated. For a great number of filled subbands the frequencies of the zero sound and spin waves in a degenerate electron gas experience oscillations of the type of de Haas-van Alphen and Aharonov-Bohm with changing the density of electrons and magnetic flux.
Tunneling and filtering characteristics of cascaded ɛ-negative metamaterial layers sandwiched by double-positive layers
Authors: Liu Chien-Hao , Behdad Nader
Published: January 2012

In this paper, we examine the electromagnetic (EM) wave tunneling and filtering characteristics of multi-layer structures composed of an arbitrary number of ɛ-negative (Epsilon-negative or ENG) metamaterial layers sandwiched by very thin double-positive (DPS) layers with high dielectric constant values. We explain the phenomenon of EM wave tunneling through this propagation barrier by drawing an analogy between this problem and a generalized coupled resonator system. Using this analogy, we demonstrate that a multi-layer structure composed of N DPS layers (N ≥ 2 is an integer number) that sandwich N-1 ENG layers can not only be made transparent in a frequency range where the ENG layers are normally opaque but also be designed to provide a desired spectral filtering characteristics. Furthermore, we present an analytical method for synthesizing such multi-layer spectral filters from the characteristics of their desired responses. The proposed synthesis procedure can be used to develop spatial filters operating throughout the microwave and mm-wave frequency bands as well as multi-layer metallo-dielectric filters at optical wavelengths. We demonstrate the validity of the proposed analytical synthesis method using full-wave numerical electromagnetic simulations. Finally, using the duality principle, we expand these analytical results to the problem of EM wave tunneling through multiple μ-negative layers surrounded by thin DPS layers with high relative permeability values.
Fully programmable single-photon detection module for InGaAs/InP single-photon avalanche diodes with clean and sub-nanosecond gating transitions
Authors: Tosi Alberto , Della Frera Adriano , Bahgat Shehata Andrea , Scarcella Carmelo
Published: January 2012

We present the design and characterization of a modern near-infrared photon counting module, able to exploit the best performance of InGaAs/InP single-photon avalanche diodes for the detection of fast and faint optical signals up to 1.7 μm. Such instrument is suitable for many applications, thanks to the user-friendly interface and the fully adjustable settings of all operating parameters. We extensively characterized both the electronics and the detector, and we validated such instrument up to 133 MHz gate repetition frequency, for photon-counting and photon-timing applications, with very clean temporal response and excellent timing performance of less than 100 ps.
Theoretical investigation of high velocity, temperature compensated Rayleigh waves along AlN/SiC substrates for high sensitivity mass sensors
Authors: Caliendo Cinzia
Published: January 2012

The operation of electroacoustic devices based on surface acoustic waves (SAW) propagation along β-SiC/AlN and amorphous-SiC/AlN substrates is theoretically studied with respect to the AlN film thickness, the SAW propagation direction, temperature and electric boundary conditions. GHz-range, enhanced electroacoustic coupling coefficient, temperature compensated around 20 °C electroacoustic devices are the advantages of SiC/AlN composite structures. These structures are also suitable for the implementation of sensors with improved performances with respect to SAW devices based on bulk single crystal piezoelectric substrates. The structures feasibility was confirmed by structural investigation and quantitative analysis of sputtered amorphous-SiC and AlN films on Si substrates.
Impact of gate work-function on memory characteristics in Al2O3/HfOx/Al2O3/graphene charge-trap memory devices
Authors: Lee Sejoon , Song Emil B. , Kim Sungmin , Seo David H. , Seo Sunae , Won Kang Tae , Wang Kang L.
Published: January 2012

Graphene-based non-volatile memory devices composed of a single-layer graphene channel and an Al2O3/HfOx/Al2O3 charge-storage layer exhibit memory functionality. The impact of the gate material’s work-function (Φ) on the memory characteristics is investigated using different types of metals [Ti (ΦTi = 4.3 eV) and Ni (ΦNi = 5.2 eV)]. The ambipolar carrier conduction of graphene results in an enlargement of memory window (ΔVM), which is ∼4.5 V for the Ti-gate device and ∼9.1 V for the Ni-gate device. The increase in ΔVM is attributed to the change in the flat-band condition and the suppression of electron back-injection within the gate stack.
Comparison of two-body and three-body decomposition of ethanedial, propanal, propenal, n-butane, 1-butene, and 1,3-butadiene
Authors: Chin Chih-Hao , Lee Shih-Huang
Published: January 2012

We investigated two-body (binary) and three-body (triple) dissociations of ethanedial, propanal, propenal, n-butane, 1-butene, and 1,3-butadiene on the ground potential-energy surfaces using quantum-chemical and Rice-Ramsperger-Kassel-Marcus calculations; most attention is paid on the triple dissociation mechanisms. The triple dissociation includes elimination of a hydrogen molecule from a combination of two separate terminal hydrogen atoms; meanwhile, the rest part simultaneously decomposes to two stable fragments, e.g., C2H4, C2H2, or CO. Transition structures corresponding to the concerted triple dissociation were identified using the B3LYP/6-311G(d,p) level of theory and total energies were computed using the method CCSD(T)/6-311+G(3df, 2p). The forward barrier height of triple dissociation has a trend of ethanedial < propanal < propenal < n-butane < 1-butene < 1,3-butadiene, pertaining to the reaction enthalpy. Ratios of translational energies of three separate fragments could be estimated from the transition structure of triple dissociation. The synchronous concerted dissociation of propanal, propenal, and 1-butene leading to three different types of molecular fragments by breaking nonequivalent chemical bonds is rare. The triple dissociation of propanal, n-butane, 1-butene, and 1,3-butadiene were investigated for the first time. To outline a whole picture of dissociation mechanisms, some significant two-body dissociation channels were investigated for the calculations of product branching ratios. The triple dissociation plays an important role in the three carbonyl compounds, but plays a minor or negligible role in the three hydrocarbons.
Surface passivation of Cu(In,Ga)Se2 using atomic layer deposited Al2O3
Authors: Hsu W.-W. , Chen J. Y. , Cheng T.-H. , Lu S. C. , Ho W.-S. , Chen Y.-Y. , Chien Y.-J. , Liu C. W.
Published: January 2012

With Al2O3 passivation on the surface of Cu(In,Ga)Se2, the integrated photoluminescence intensity can achieve two orders of magnitude enhancement due to the reduction of surface recombination velocity. The photoluminescence intensity increases with increasing Al2O3 thickness from 5 nm to 50 nm. The capacitance-voltage measurement indicates negative fixed charges in the film. Based on the first principles calculations, the deposition of Al2O3 can only reduce about 35% of interface defect density as compared to the unpassivated Cu(In,Ga)Se2. Therefore, the passivation effect is mainly caused by field effect where the surface carrier concentration is reduced by Coulomb repulsion.
Antiferromagnetic coupling across silicon regulated by tunneling currents
Authors: Gareev R. R. , Schmid M. , Vancea J. , Back C. H. , Schreiber R. , Bürgler D. , Schneider C. M. , Stromberg F. , Wende H.
Published: January 2012

We report on the enhancement of antiferromagnetic coupling in epitaxial Fe/Si/Fe structures by voltage-driven spin-polarized tunneling currents. Using the ballistic electron magnetic microscopy, we established that the hot-electron collector current reflects magnetization alignment and the magnetocurrent exceeds 200% at room temperature. The saturation magnetic field for the collector current corresponding to the parallel alignment of magnetizations rises up with the tunneling current, thus demonstrating stabilization of the antiparallel alignment and increasing antiferromagnetic coupling. We connect the enhancement of antiferromagnetic coupling with local dynamic spin torques mediated by spin-polarized tunneling electrons.
Intrinsic parameter extraction of a-InGaZnO thin-film transistors by a gated-four-probe method
Authors: Jeong Jaewook , Kim Joonwoo , Jun Lee Gwang , Choi Byeong-Dae
Published: January 2012

We analyzed the intrinsic electrical characteristics of amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) using a gated-four-probe method. Based on the back channel potential, the extraction of intrinsic field-effect mobility (μFEi) and parasitic resistance in source (Rs) and drain (Rd) electrodes was performed especially for low VGS and VDS conditions. The resulting μFEi showed typical VGS dependency of amorphous semiconductor TFTs. However, Rs and Rd showed that there can be non-uniformity in source/drain parasitic resistance, which indicates that a separate analysis of the parameters of each electrode is essential for further improvement of the performance of a-IGZO TFTs.
High pressure rheometer for in situ formation and characterization of methane hydrates
Authors: Webb Eric B. , Rensing Patrick J. , Koh Carolyn A. , Dendy Sloan E. , Sum Amadeu K. , Liberatore Matthew W.
Published: January 2012

We present a novel setup for a high pressure rheometer operating with concentric cylinders geometry for in situ studies of hydrate formation and rheological characterization. The apparatus uses an external high pressure mixing cell to saturate water-in-oil emulsions with methane gas. The capability of mixing combined with a true rheometer design make this apparatus unique in terms of setup and sample formation. We have used the apparatus to form gas hydrates in situ from water-in-oil emulsions and characterize suspension rheological properties such as yield stress and shear-thinning behavior.
Continual in-plane displacement measurement with temporal wavelet transform speckle pattern interferometry
Authors: Gao Zhan , Deng Yan , Duan Yiting , Zhang Zhifeng , Wei Cheng , Chen Shiqian , Cui Jianying , Feng Qibo
Published: January 2012

A heterodyne temporal speckle pattern interferometer that measures the in-plane displacement dynamically has been built. The object is displaced in its plane continuously and the frequency-modulated output signals with a carrier frequency are recorded by a CCD camera. The displacement information is extracted with wavelet transform technique. Preliminary experiments have been performed with such interferometer. The respective measurement results recovered from wavelet transform and Fourier transform are compared.
Phase coherent states with circular Jacobi polynomials for the pseudoharmonic oscillator
Authors: Mouayn Zouhaïr
Published: January 2012

We construct a class of generalized phase coherent states ∣eiθ; γ, α, ɛ >, indexed by points eiθ of the unit circle and depending on three positive parameters γ, α, and ɛ, by replacing the labeling coefficient \documentclass[12pt]{minimal}\begin{document}$z^{n}/\sqrt{n!}$\end{document}zn/n! of the canonical coherent states by circular Jacobi polynomials \documentclass[12pt]{minimal}\begin{document}$g_{n}^{\gamma }\left( e^{i\theta }\right)$\end{document}gnγeiθ with parameter γ ⩾ 0. The special case of γ = 0 corresponds to the well-known phase coherent states. The constructed states are superposition of eigenstates of a one-parameter pseudoharmonic oscillator depending on α and constitute a resolution of the identity of the state Hilbert space at the limit ɛ → 0+. Closed form for their wavefunctions are obtained in the case α = γ + 1 and their associated coherent states transforms are defined.
Exploring the dynamics of dimer crossing over a Kramers type potential
Authors: Asfaw Mesfin , Shiferaw Yohannes
Published: January 2012

We explore the escape rate of a dimer crossing a potential barrier using both analytical and numerical approaches. We find that for small coupling strength k, the barrier hopping can be well approximated by a two step reaction scheme where one monomer hops over the barrier and is then followed by the other. In this regime the escape rate increases with k showing that the cooperativity between monomers enhances the crossing rate. However, in the limit of large coupling strength, applying the method of adiabatic elimination, we find that the escape rate is a decreasing function of k. Thus, we find that the escape rate is a non-monotonic function of the spring constant which is peaked at an optimal coupling strength. Furthermore, in the presence of a weak periodic signal, we show that the system response to the periodic signal is pronounced at a particular spring constant showing the dimer can be transported rapidly across the reaction coordinate in a half period.
Structure dependence in hybrid Si nanowire/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) solar cells: Understanding photovoltaic conversion in nanowire radial junctions
Authors: Lu Wenhui , Chen Qi , Wang Bing , Chen Liwei
Published: January 2012

Hybrid Si/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) solar cells based on nanowire array structures with radial and axial junctions are prepared and investigated. Compared to axial junction cells, radial junction cells exhibit much higher external quantum efficiency for long wavelength light due to improved separation of photogenerated charge carriers, resulting in more than 10 times higher power conversion efficiency (PCE). By tuning the height of nanowire array for the hybrid radial junction cells and investigating the external quantum efficiency and open circuit voltage decay, we identify that inefficient carrier collection due to interfacial recombination is the major limiting factor for the hybrid radial junction cell performance.
A high dynamic range data acquisition system for a solid-state electron electric dipole moment experiment
Authors: Kim Young Jin , Kunkler Brandon , Liu Chen-Yu , Visser Gerard
Published: January 2012

We have built a high precision (24-bit) data acquisition (DAQ) system capable of simultaneously sampling eight input channels for the measurement of the electric dipole moment of the electron. The DAQ system consists of two main components: a master board for DAQ control and eight individual analog-to-digital converter (ADC) boards for signal processing. This custom DAQ system provides galvanic isolation of the ADC boards from each other and the master board using fiber optic communication to reduce the possibility of ground loop pickup and attain ultimate low levels of channel cross-talk. In this paper, we describe the implementation of the DAQ system and scrutinize its performance.
Magnetic and transport properties of Mn3−xGa/MgO/Mn3−xGa magnetic tunnel junctions: A first-principles study
Authors: Bai Zhaoqiang , Cai Yongqing , Shen Lei , Yang Ming , Ko Viloane , Han Guchang , Feng Yuanping
Published: January 2012

Magnetic and transport properties of Mn3−xGa/MgO/Mn3−xGa (0 ≤ x ≤ 1) magnetic tunnel junctions are studied using first-principles approach based on density functional theory and non-equilibrium Green’s function. Perpendicular magnetization, of which the magnetic anisotropy energy reaches more than 1 meV/unit-cell, is confirmed to be energetically favoured by both Mn2Ga and Mn3Ga thin films. Furthermore, despite high spin-polarization at the Fermi energy for both these compounds as reported, our transport calculation shows considerable disparity in the transmission behaviour between Mn2Ga/MgO/Mn2Ga(001) and Mn3Ga/MgO/Mn3Ga(001) magnetic tunnel junctions: huge optimistic tunneling magnetoresistance ratio of 103% for the former, and nevertheless, no tunneling magnetoresistance effect absolutely for the latter. This phenomenon is attributed to the symmetry selective filtering effect of the MgO spacer. On this premise, Mn3−xGa compounds with low Mn concentration are predicted to be promising candidate materials to serve as the electrodes of spin-transfer torque devices in the next-generation data storage technique.
Directed jetting from collapsing cavities exposed to focused ultrasound
Authors: Gerold B. , Glynne-Jones P. , McDougall C. , McGloin D. , Cochran S. , Melzer A. , Prentice P.
Published: January 2012

We demonstrate directed jetting from pulsed laser-induced cavities subjected to a burst of focused ultrasound. Alignment of the ultrasound focus and the pressure amplitudes in the vicinity of the cavity dictate the direction and length of the resulting jet, respectively. We interpret our observations in terms of radiation forces exerted on the cavity, due to the pressure gradient introduced to the ultrasound focus by its presence. We support our hypothesis with a linear analysis of the force distribution across the cavity surface, at the moment of maximum inflation, which shows reasonable predictive agreement with the observed jet characteristics.
Phase dependent room-temperature ferromagnetism of Fe-doped TiO2 nanorods
Authors: Patel S. K. S. , Kurian S. , Gajbhiye N. S.
Published: January 2012

Fe-doped TiO2(B) and anatase phases were synthesized at different thermal treatment conditions using Fe-doped hydrogen titanate nanorods as a precursor. X-ray diffraction, Raman and Mössbauer studies ruled out the formation of secondary phase of either metallic Fe or iron oxide cluster in the samples and confirmed the ferromagnetism have originated from the defects. Mössbauer spectroscopy studies show a doublet and measured isomer shifts support the high spin Fe3+ charge state occupying the Ti4+ sites with associated changes in local lattice environment. The magnetization at room-temperature of the TiO2(B) sample is 0.020 emu/g whereas that of anatase sample is 0.015 emu/g. The decrease of magnetization with the structural phase transformation from TiO2(B) to anatase is attributed to the reduction in number of defects (oxygen vacancy) during the transformation process. Existence of these defects was further supported by the photoluminescence measurements.
MBE growth of high electron mobility 2DEGs in AlGaN/GaN heterostructures controlled by RHEED
Authors: Broxtermann D. , Sivis M. , Malindretos J. , Rizzi A.
Published: January 2012

We have grown 2DEG AlGaN/GaN heterostructures by molecular beam epitaxy (MBE) with electron mobilities up to 21500 cm2V−1s−1 at 2 K. In-situ RHEED was applied to optimize different aspects of Ga-rich growth. This paper gives a compact overview of the experimental key aspects that significantly affect the low temperature electron mobility in AlGaN/GaN heterostructures. Growth at the transition towards Ga droplet formation produced the best results. A quantitative analysis of the magnetoresistance confirmes scattering at dislocations as the dominant scattering process at low temperature.
Convergent structural alterations define SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeler as a central tumor suppressive complex in pancreatic cancer
Authors: Shain A. Hunter , Giacomini Craig P. , Matsukuma Karen , Karikari Collins A. , Bashyam Murali D. , Hidalgo Manuel , Maitra Anirban , Pollack Jonathan R.
Published: January 2012

Defining the molecular genetic alterations underlying pancreatic cancer may provide unique therapeutic insight for this deadly disease. Toward this goal, we report here an integrative DNA microarray and sequencing-based analysis of pancreatic cancer genomes. Notable among the alterations newly identified, genomic deletions, mutations, and rearrangements recurrently targeted genes encoding components of the SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeling complex, including all three putative DNA binding subunits (ARID1A, ARID1B, and PBRM1) and both enzymatic subunits (SMARCA2 and SMARCA4). Whereas alterations of each individual SWI/SNF subunit occurred at modest-frequency, as mutational “hills” in the genomic landscape, together they affected at least one-third of all pancreatic cancers, defining SWI/SNF as a major mutational “mountain.” Consistent with a tumor-suppressive role, re-expression of SMARCA4 in SMARCA4-deficient pancreatic cancer cell lines reduced cell growth and promoted senescence, whereas its overexpression in a SWI/SNF-intact line had no such effect. In addition, expression profiling analyses revealed that SWI/SNF likely antagonizes Polycomb repressive complex 2, implicating this as one possible mechanism of tumor suppression. Our findings reveal SWI/SNF to be a central tumor suppressive complex in pancreatic cancer.
Kruppel-like factor 5 (KLF5) is critical for conferring uterine receptivity to implantation
Authors: Sun Xiaofei , Zhang Liqian , Xie Huirong , Wan Huajing , Magella Bliss , Whitsett Jeffrey A. , Dey Sudhansu K.
Published: January 2012

A blastocyst will implant only when the uterus becomes receptive. Following attachment, luminal epithelial cells undergo degeneration at the site of the blastocyst. Although many genes critical for uterine receptivity are primarily regulated by ovarian hormones,
Kruppel-like factor 5
(
KLF5
), a zinc finger-containing transcription factor, is persistently expressed in epithelial cells independently of ovarian hormones. Loss of uterine
Klf5
causes female infertility due to defective implantation. Cox2 is normally expressed in the luminal epithelium and stroma at the site of blastocyst attachment, but luminal epithelial COX2 expression is absent with loss of
Klf5
. This is associated with the retention of the epithelium around the implantation chamber with arrested embryonic growth. These results suggest that
Klf5
is indispensable for normal implantation.
Ubiquitination, localization, and stability of an anti-apoptotic BCL2-like protein, BCL2L10/BCLb, are regulated by Ubiquilin1
Authors: Beverly Levi J. , Lockwood William W. , Shah Parag P. , Erdjument-Bromage Hediye , Varmus Harold
Published: January 2012

We have previously shown that all six members of the anti-apoptotic BCL2 gene family can cooperate with (myelocytomatosis oncogene) MYC in a mouse model of leukemia, but three of them are significantly less potent contributors to leukemogenicity than the other three. The protein encoded by one of these less potent genes, BCL2L10/BCLb, was recently shown to vary dramatically in many primary human cancers by immunohistochemistry, and the protein levels were inversely correlated with survival in patients with several cancer types. We examined BCLb mRNA in a panel of human cancer cell lines and did not observe the extensive variation in mRNA that would be required to explain the vast differences in protein levels. We found that the levels of BCLb protein diminish quickly after inhibition of protein synthesis with cycloheximide, so we searched for interacting proteins that might affect posttranslational stability of BCLb. Using a variety of approaches, including immunoaffinity and mass spectrometry, we identified a protein, Ubiquilin1 (Ubqln), that specifically interacts with BCLb, and not with other anti-apoptotic BCL2-like proteins. Ubqln stabilizes BCLb protein, while also promoting monoubiquitination on multiple lysine residues and relocation to the cytosol. Furthermore, primary lung adencarcinomas have more Ubqln mRNA than normal adjacent lung tissue, and higher Ubqln mRNA levels are associated with shorter survival of lung cancer patients, suggesting that potentiation of the anti-apoptotic potential of BCLb through regulation of its stability by Ubqln may be an important factor in tumor progression.
Derlin-1 and UBXD8 are engaged in dislocation and degradation of lipidated ApoB-100 at lipid droplets
Authors: Suzuki Michitaka , Otsuka Toshihiko , Ohsaki Yuki , Cheng Jinglei , Taniguchi Takako , Hashimoto Hisashi , Taniguchi Hisaaki , Fujimoto Toyoshi
Published: January 2012

Apolipoprotein B-100 (ApoB) is the principal component of very low density lipoprotein. Poorly lipidated nascent ApoB is extracted from the Sec61 translocon and degraded by proteasomes. ApoB lipidated in the endoplasmic reticulum (ER) lumen is also subjected to proteasomal degradation, but where and how it dislocates to the cytoplasm remain unknown. In the present study, we demonstrate that ApoB after lipidation is dislocated to the cytoplasmic surface of lipid droplets (LDs) and accumulates as ubiquitinated ApoB in Huh7 cells. Depletion of UBXD8, which is almost confined to LDs in this cell type, decreases recruitment of p97 to LDs and causes an increase of both ubiquitinated ApoB on the LD surface and lipidated ApoB in the ER lumen. In contrast, abrogation of Derlin-1 function induces an accumulation of lipidated ApoB in the ER lumen but does not increase ubiquitinated ApoB on the LD surface. UBXD8 and Derlin-1 bind with each other and with lipidated ApoB and show colocalization around LDs. These results indicate that ApoB after lipidation is dislocated from the ER lumen to the LD surface for proteasomal degradation and that Derlin-1 and UBXD8 are engaged in the predislocation and postdislocation steps, respectively.
Trends in death attributed to heart failure over the past two decades in Europe
Authors: Laribi Said , Aouba Albertine , Nikolaou Maria , Lassus Johan , Cohen‐Solal Alain , Plaisance Patrick , Pavillon Gérard , Jois Preeti , Fonarow Gregg C. , Jougla Eric , Mebazaa Alexandre ,   the GREAT network
Published: January 2012

Aims

Little is known regarding temporal trends in mortality attributed to heart failure (HF) from a population perspective. The aim of this study was to assess the mortality related to HF as an underlying cause during the last 20 years in seven European countries.

Methods and results

The number of deaths with HF as the underlying cause was collected in seven European states: Germany, Greece, England and Wales, Spain, France, Finland, and Sweden from 1987 to 2008. Disease coding for HF was based on the International Classification of Diseases (ICD 9th and 10th versions). We computed age‐standardized death rates (SDRs) per 100 000 inhabitants. Mean age at death from HF was also calculated for the same period. In the seven studied countries, the HF SDR decreased continuously from 54.2 (1987) to 32.6 (2008). Despite differences in the early 1990s, SDRs related to HF seemed to converge, in these seven European countries, to ~30 deaths per 100 000 population in the near future, for both men and women. During the study period, the mean age at death increased from 80.0 to 82.7 years. Half of the deaths from HF occurred in hospital, without change over time.

Conclusion

There has been a 40% reduction of the SDR due to HF in seven European countries during two decades and a concomitant increase in the mean age at death from HF. We hypothesize that these results may be related to a better management of chronic and acute HF patients over the past 20 years.
Flagella Mediate Endophytic Competence Rather Than Act as MAMPS in Rice–Azoarcus sp. Strain BH72 Interactions
Authors: Buschart Anna , Sachs Sabrina , Chen Xi , Herglotz Julia , Krause Andrea , Reinhold-Hurek Barbara
Published: January 2012

Azoarcus sp. strain BH72 is an endophytic betaproteobacterium able to colonize rice roots without induction of visible disease symptoms. BH72 possesses one polar flagellum. The genome harbors three copies of putative fliC genes, generally encoding the major structural protein flagellin. It is not clear whether, in endophytic interactions, flagella mediate endophytic competence or act as MAMPs (microbe-asscociated molecular patterns) inducing plant defense responses. Therefore, possible functions of the three FliC proteins were investigated. Only fliC3 was found to be highly expressed in pure culture and in association with rice roots and to be required for bacterial motility, suggesting that it encodes the major flagellin. Endophytic colonization of rice roots was significantly reduced in the in-frame deletion mutant, while the establishment of microcolonies on the root surface was not affected. Moreover, an elicitation of defense responses related to FliC3 was not observed. In conclusion, our data support the hypothesis that FliC3 does not play a major role as a MAMP but is required for endophytic colonization in the Azoarcus-rice interaction, most likely for spreading inside the plant.