bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of secondary signs as shown by unenhanced helical computed tomography in patients with uric acid or calcium ureteral stones
Authors: Chou Yii‐Her , Chou Wei‐Po , Liu Mu‐En , Li Wei‐Ming , Li Ching‐Chia , Liu Chia‐Chu , Juan Yung‐Shun , Pan Shu‐Ching
Published: April 2012

Unenhanced helical computed tomography (UHCT) has evolved into a well‐accepted diagnostic method in patients with suspected ureterolithiasis. UHCT not only shows stones within the lumen of the ureter, it also permits evaluation of the secondary signs associated with ureteral obstruction from stones. However, there we could find no data on how secondary signs might differ in relation to different compositions of ureteral stones. In this study, we compared the degree of secondary signs revealed by UHCT in uric acid stone formers and in patients forming calcium stones. We enrolled 117 patients with ureteral stones who underwent UHCT examination and Fourier transform infra‐red analysis of stone samples. Clinical data were collected as follows: age, sex, estimated glomerular filtration rate (eGFR), urine pH, and radiological data on secondary signs apparent on UHCT. The uric acid stone formers had significantly lower urine pH and eGFR in comparison to calcium stone formers, and on UHCT they also had a higher percentage of the secondary signs, including rim sign (78.9% vs. 60.2%), hydroureter (94.7% vs. 89.8%), perirenal stranding (84.2% vs. 59.2%) and kidney density difference (73.7% vs. 50.0%). The radiological difference was statistically significant for perirenal stranding (p = 0.041). In conclusion, we found that UHCT scanning reveals secondary signs to be more frequent in patients with uric acid ureteral stones than in patients with calcium stones, a tendency that might result from an acidic urine environment.
Ancient harbors and Holocene morphogenesis of the Ras Ibn Hani peninsula (Syria)
Authors: Marriner Nick , Goiran Jean-Philippe , Geyer Bernard , Matoïan Valérie , al-Maqdissi Michel , Leconte Marion , Carbonel Pierre
Published: April 2012

Ras Ibn Hani peninsula, a wave-dominated tombolo (800 × 1000 m) on the Syrian coast, provides evidence for significant Holocene changes that can be linked to geological inheritance, rising post-glacial sea level, sediment supply and human impacts. Initial development of Ras Ibn Hani's coastal system began ~ 8000 years ago when shallow marine environments formed in a context of rising post-glacial sea level. Following relative sea-level stabilization ~ 6000 cal yr BP, beach facies trace the gradual formation of a wave-dominated sandbank fronted by a ~ 2300 × ~ 500 m palaeo-island whose environmental potentiality was attractive to Bronze Age societies. A particularly rapid phase of tombolo accretion is observed after ~ 3500 cal yr BP characterised by a two- to fourfold increase in sedimentation rates. This is consistent with (i) a pulse in sediment supply probably driven by Bronze Age/Iron Age soil erosion in local catchments, and (ii) positive feedback mechanisms linked to regionally attested neotectonics. Archaeological remains and radiocarbon datings confirm that the subaerial tombolo was probably in place by the Late Bronze Age. These data fit tightly with other eastern Mediterranean tombolo systems suggesting that there is a great deal of predictability to their geology and stratigraphy at the regional scale.
Boundary-element method for the prediction of performance of flapping foils with leading-edge separation
Authors: Pan Yulin , Dong Xiaoxia , Zhu Qiang , Yue Dick K. P.
Published: April 2012

A numerical model based on a boundary-element method is developed to predict the performance of flapping foils for the general cases where vorticities are shed near the leading edge as well as from the trailing edge. The shed vorticities are modelled as desingularized thin shear layers which propagate with the local flow velocity. Special treatments are developed to model the unsteady and alternating leading-edge separation (LES), which is a main element of difficulty for theoretical and numerical analyses of general flapping foils. The present method is compared with existing experiments where it is shown that the inclusion of LES significantly improves the prediction of thrust and efficiency, obtaining excellent agreement with measurements over a broad range of flapping frequencies (Strouhal number) and motion amplitudes (maximum angle of attack). It is found that the neglect of LES leads to substantial over-prediction of the thrust (and efficiency). The effects of LES on thrust generation in terms of the circulation around the foil, the steady and unsteady thrust components, and the vortex-induced pressure on the foil are elucidated. The efficiency and robustness of the method render it suitable for design optimization which generally requires large numbers of performance evaluations. To illustrate this, we present a sample problem of designing the flapping motion, with the inclusion of higher harmonic components, to maximize the efficiency under specified thrust. When optimal higher harmonic motions are included, the performance of the flapping foil is appreciably improved, mitigating the adverse effects of LES vortex on the performance.
Two-way coupled stochastic model for dispersion of inertial particles in turbulence
Authors: Pai Madhusudan G. , Subramaniam Shankar
Published: April 2012

Turbulent two-phase flows are characterized by the presence of multiple time and length scales. Of particular interest in flows with non-negligible interphase momentum coupling are the time scales associated with interphase turbulent kinetic energy transfer (TKE) and inertial particle dispersion. Point-particle direct numerical simulations (DNS) of homogeneous turbulent flows laden with sub-Kolmogorov size particles report that the time scale associated with the interphase TKE transfer behaves differently with Stokes number than the time scale associated with particle dispersion. Here, the Stokes number is defined as the ratio of the particle momentum response time scale to the Kolmogorov time scale of turbulence. In this study, we propose a two-way coupled stochastic model (CSM), which is a system of two coupled Langevin equations for the fluctuating velocities in each phase. The basis for the model is the Eulerian–Eulerian probability density function formalism for two-phase flows that was established in Pai & Subramaniam (J. Fluid Mech., vol. 628, 2009, pp. 181–228). This new model possesses the unique capability ofsimultaneouslycapturing the disparate dependence of the time scales associated with interphase TKE transfer and particle dispersion on Stokes number. This is ascertained by comparing predicted trends of statistics of turbulent kinetic energy and particle dispersion in both phases from CSM, for varying Stokes number and mass loading, with point-particle DNS datasets of homogeneous particle-laden flows.
Rights Offerings, Subscription Period, Shareholder Takeup, and Liquidity
Authors: Balachandran Balasingham , Faff Robert , Theobald Michael , van Zijl Tony
Published: April 2012

We examine the role of shareholder takeup in rights offerings on the subscription period price reaction and liquidity. Our results indicate that takeup information is reflected in price adjustments over the subscription period and that quality-related information disclosed on the rights announcement date further impacts prices in this period. Higher shareholder takeup improves liquidity. We do find some evidence of inefficiencies in the adjustment process over the subscription period that, in part, is consistent with a model where markets are characterized by overconfident investors and that also articulates with takeup information arriving in the market.
Limits of Electoral Equality and Political Representation
Authors: Chryssogonos Kostas , Stratilatis Costas
Published: April 2012

Constitutional limits to the discretion of the legislature in forming the electoral system — Political equality — Equal suffrage — Equal opportunities for political parties — Free expression of popular will — Functionality of the parliament — Concrete normative standards for assessing the constitutionality of an electoral system — Conception of parliamentary democracy emphasising representation of political minorities and protection from ‘tyranny of the majority’
Evidence-Based Practice Application: A Goal for Anaesthetic and Recovery Nurses
Authors: Brady Joni M.
Published: April 2012

Historically speaking, nursing actions were often based on opinions or habits with very little scientific evidence available to guide practice. The nursing process has been widely employed in basic nursing education programmes for several decades. The subsequent addition of the critical thinking component has enabled the practitioner to apply reasoning and formulate appropriate judgments about his/her patient's needs. Although many nurses lack formal education in research and evidence-based practice (EBP), frontline practitioners occupy a perfect position to stimulate and impact adoption of EBP in practice. Incorporation of EBP education and guided instruction in the EBP process for anaesthetic and recovery nurses can only serve to sustain its primary goal of combining the best available evidence with skilled professional opinion to achieve safe and sound practice at the bedside.
Spatial width oscillations in meandering rivers at equilibrium
Authors: Luchi R. , Bolla Pittaluga M. , Seminara G.
Published: April 2012

In canaliform rivers channel width at bankfull stage is fairly uniform though, at bend apexes, it is typically smaller than at crossings. Conversely, in sinuous point bar rivers bankfull width peaks at bend apexes. Why? Is there any mechanistic constraint that forces this different behavior? We provide an answer to these questions investigating how bankfull width must vary in a sequence of sine‐generated meanders in order for the constraints of equilibrium (constant flow discharge and sediment flux) to be satisfied. With the help of a 3‐D fully nonlinear analytical model of flow and bed topography in meandering rivers with variable width, we show that, in a meandering channel characterized by a constant longitudinal free‐surface slope, the equilibrium width thus obtained oscillates with a frequency twice the frequency of channel curvature and experiences the maximum width close to inflection points. This pattern is typically observed in canaliform rivers. We then show that a similar pattern is observed in sinuous point bar rivers, provided the hydrodynamic width (width of the free surface) is replaced by the active width, namely the width of the portion of the cross section where transport occurs at formative conditions. Theoretical results are substantiated by a satisfactory comparison with field observations referring to the Mississippi River (United States) and to the Bollin River (United Kingdom).
Predicting land cover changes in the Amazon rainforest: An ocean‐atmosphere‐biosphere problem
Authors: Pereira Marcos Paulo Santos , Malhado Ana Cláudia Mendes , Costa Marcos Heil
Published: April 2012

Accurate studies of the impacts of climate change on the distribution of major vegetation types are essential for developing effective conservation and land use policy. Such studies require the development of models that accurately represent the complex and interacting biophysical factors that influence regional patterns of vegetation. Here we investigate the impacts of Sea Surface Temperature (SST) on the vegetation of the Amazon, testing the hypothesis that changes in Amazonian vegetation structure are a consequence of an ocean‐atmosphere‐biosphere interaction. We design a numerical experiment in which we force a coupled climate‐biosphere model by 10 SST patterns produced by different IPCC AR4 models, for the A2 scenario for the period 2000–2050. Simulations for 2011–2050 show that certain patterns of SST are likely to decrease the ensemble for tropical evergreen rainforest and savanna, and that these areas will be occupied mainly by tropical deciduous rainforest, emitting an average of 0.53 Pg‐C.yr−1 during the transition.
Systematic and random error components in satellite precipitation data sets
Authors: AghaKouchak Amir , Mehran Ali , Norouzi Hamidreza , Behrangi Ali
Published: April 2012

This study contributes to characterization of satellite precipitation error which is fundamental to develop uncertainty models and bias reduction algorithms. Systematic and random error components of several satellite precipitation products are investigated over different seasons, thresholds and temporal accumulations. The analyses show that the spatial distribution of systematic error has similar patterns for all precipitation products. However, the systematic (random) error of daily accumulations is significantly less (more) than that of high resolution 3‐hr data. One should note that the systematic biases of satellite precipitation are distinctively different in the summer and winter. The systematic (random) error is remarkably higher (lower) during the winter. Furthermore, the systematic error seems to be proportional to the rain rate magnitude. The findings of this study highlight that bias removal methods should take into account the spatiotemporal characteristics of error as well as the proportionality of error to the magnitude of rain rate.
A conserved cysteine residue is involved in disulfide bond formation between plant plasma membrane aquaporin monomers
Authors: Bienert Gerd P. , Cavez Damien , Besserer Arnaud , Berny Marie C. , Gilis Dimitri , Rooman Marianne , Chaumont François
Published: April 2012

AQPs (aquaporins) are conserved in all kingdoms of life and facilitate the rapid diffusion of water and/or other small solutes across cell membranes. Among the different plant AQPs, PIPs (plasma membrane intrinsic proteins), which fall into two phylogenetic groups, PIP1 and PIP2, play key roles in plant water transport processes. PIPs form tetramers in which each monomer acts as a functional channel. The intermolecular interactions that stabilize PIP oligomer complexes and are responsible for the resistance of PIP dimers to denaturating conditions are not well characterized. In the present study, we identified a highly conserved cysteine residue in loop A of PIP1 and PIP2 proteins and demonstrated by mutagenesis that it is involved in the formation of a disulfide bond between two monomers. Although this cysteine seems not to be involved in regulation of trafficking to the plasma membrane, activity, substrate selectivity or oxidative gating of ZmPIP1s (Zm is Zea mays), ZmPIP2s and hetero-oligomers, it increases oligomer stability under denaturating conditions. In addition, when PIP1 and PIP2 are co-expressed, the loop A cysteine of ZmPIP1;2, but not that of ZmPIP2;5, is involved in the mercury sensitivity of the channels.
Homers regulate calcium entry and aggregation in human platelets: a role for Homers in the association between STIM1 and Orai1
Authors: Jardin Isaac , Albarrán Letizia , Bermejo Nuria , Salido Ginés M. , Rosado Juan A.
Published: April 2012

Homer is a family of cytoplasmic adaptor proteins that play different roles in cell function, including the regulation of G-protein-coupled receptors. These proteins contain an Ena (Enabled)/VASP (vasodilator-stimulated phosphoprotein) homology 1 domain that binds to the PPXXF sequence motif, which is present in different Ca2+-handling proteins such as IP3 (inositol 1,4,5-trisphosphate) receptors and TRPC (transient receptor potential canonical) channels. In the present study we show evidence for a role of Homer proteins in the STIM1 (stromal interaction molecule 1)–Orai1 association, as well as in the TRPC1–IP3RII (type II IP3 receptor) interaction, which might be of relevance in platelet function. Treatment of human platelets with thapsigargin or thrombin results in a Ca2+-independent association of Homer1 with TRPC1 and IP3RII. In addition, thapsigargin and thrombin enhanced the association of Homer1 with STIM1 and Orai1 in a Ca2+-dependent manner. Interference with Homer function by introduction of the synthetic PPKKFR peptide into cells, which emulates the proline-rich sequences of the PPXXF motif, reduced STIM1–Orai1 and TRPC1– IP3RII associations, as compared with the introduction of the inactive PPKKRR peptide. The PPKKFR peptide attenuates thrombin-evoked Ca2+ entry and the maintenance of thapsigargin-induced store-operated Ca2+ entry. Finally, the PPKKFR peptide attenuated thrombin-induced platelet aggregation. The findings of the present study support an important role for Homer proteins in thrombin-stimulated platelet function, which is likely to be mediated by the support of agonist-induced Ca2+ entry.
Theory of nonlinear elasticity, stress-induced relaxation, and dynamic yielding in dense fluids of hard nonspherical colloids
Authors: Zhang Rui , Schweizer Kenneth S.
Published: April 2012

We generalize the microscopic naïve mode coupling and nonlinear Langevin equation theories of the coupled translation-rotation dynamics of dense suspensions of uniaxial colloids to treat the effect of applied stress on shear elasticity, cooperative cage escape, structural relaxation, and dynamic and static yielding. The key concept is a stress-dependent dynamic free energy surface that quantifies the center-of-mass force and torque on a moving colloid. The consequences of variable particle aspect ratio and volume fraction, and the role of plastic versus double glasses, are established in the context of dense, glass-forming suspensions of hard-core dicolloids. For low aspect ratios, the theory provides a microscopic basis for the recently observed phenomenon of double yielding as a consequence of stress-driven sequential unlocking of caging constraints via reduction of the distinct entropic barriers associated with the rotational and translational degrees of freedom. The existence, and breadth in volume fraction, of the double yielding phenomena is predicted to generally depend on both the degree of particle anisotropy and experimental probing frequency, and as a consequence typically occurs only over a window of (high) volume fractions where there is strong decoupling of rotational and translational activated relaxation. At high enough concentrations, a return to single yielding is predicted. For large aspect ratio dicolloids, rotation and translation are always strongly coupled in the activated barrier hopping event, and hence for all stresses only a single yielding process is predicted.
Low-threshold intersubband laser based on interface-scattering-rate engineering
Authors: Semtsiv M. P. , Flores Y. , Chashnikova M. , Monastyrskyi G. , Masselink W. T.
Published: April 2012

The dependence of the scattering rate between different electronic states in semiconductor heterostructures due to interface roughness on the barrier height is exploited to enhance the population inversion in intersubband lasers. Barriers with differing heights are used within a strain-compensated InGaAs-InAlAs heterostructure to either increase or decrease the interface-roughness scattering component for specific confined states. In particular, low barriers are used where the upper laser state has its highest probability, thus maximizing the lifetime of the upper laser state; the higher barriers are used where the lower laser state and the few subsequent confined states have their highest probabilities, thus minimizing the lifetime of the lower laser state. By combining differing barrier heights in this way, the lifetime of the upper laser state is increased, while simultaneously the lifetime of the lower laser state is decreased; thus, the population inversion is significantly enhanced. This design approach is demonstrated for a quantum-cascade laser emitting near 4 μm. The reduced scattering out of the upper laser level is reflected in a narrower electroluminescence spectrum of 26 meV and a reduced threshold current density of 1.75 kA/cm2 at room-temperature.
Creation and recovery of a W(111) single atom gas field ion source
Authors: Pitters Jason L. , Urban Radovan , Wolkow Robert A.
Published: April 2012

Tungsten single atom tips have been prepared from a single crystal W(111) oriented wire using the chemical assisted field evaporation and etching method. Etching to a single atom tip occurs through a symmetric structure and leads to a predictable last atom unlike etching with polycrystalline tips. The single atom tip formation procedure is shown in an atom by atom removal process. Rebuilds of single atom tips occur on the same crystalline axis as the original tip such that ion emission emanates along a fixed direction for all tip rebuilds. This preparation method could be utilized and developed to prepare single atom tips for ion source development.
The design and analysis of beam-membrane structure sensors for micro-pressure measurement
Authors: Tian Bian , Zhao Yulong , Jiang Zhuangde , Hu Bin
Published: April 2012

This paper reports the design and analysis of a type of piezoresistive pressure sensor for micro-pressure measurement with a cross beam-membrane (CBM) structure. This new silicon substrate-based sensor has the advantages of a miniature structure and high sensitivity, linearity, and accuracy. By using the finite element method to analyze the stress distribution of the new structure and subsequently deducing the relationship between structural dimensions and mechanical performances, equations used to determine the CBM structure are established. Based on the CBM model and our stress and deflections equations, sensor fabrication is then performed on the silicon wafer via a process including anisotropy chemical etching and inductively coupled plasma. The structure's merits, such as linearity, sensitivity, and repeatability, have been investigated under the pressure of 5 kPa. Our results show that the precision of these equations is ±0.19%FS, indicating that this new small-sized structure offers easy preparation, high sensitivity, and high accuracy for micro-pressure measurement.
Solvation free energies and hydration structure of N-methyl-p-nitroaniline
Authors: Ahmed Alauddin , Sandler Stanley I.
Published: April 2012

Solvation Gibbs energies of N-methyl-p-nitroaniline (MNA) in water and 1-octanol are calculated using the expanded ensemble molecular dynamics method with a force field taken from the literature. The accuracy of the free energy calculations is verified with the experimental Gibbs free energy data and found to reproduce the experimental 1-octanol/water partition coefficient to within ±0.1 in log unit. To investigate the hydration structure around N-methyl-p-nitroaniline, an independent NVT molecular dynamics simulation was performed at ambient conditions. The local organization of water molecules around the solute MNA molecule was investigated using the radial distribution function (RDF), the coordination number, and the extent of hydrogen bonding. The spatial distribution functions (SDFs) show that the water molecules are distributed above and below the nitrogen atoms parallel to the plane of aromatic ring for both the methylamino and nitro functional groups. It is found that these groups have a significant effect on the hydration of MNA with water molecules forming two weak hydrogen bonds with both the methylamino and nitro groups. The hydration structures around the functional groups in MNA in water are different from those that have been found for methylamine, nitrobenzene, and benzene in aqueous solutions, and these differences together with weak hydrogen bonds explain the lower solubility of MNA in water. The RDFs together with SDFs provide a tool for the understanding the hydration of MNA (and other molecules) and therefore their solubility.
Mesoscale modeling of intergranular bubble percolation in nuclear fuels
Authors: Millett Paul C. , Tonks Michael , Biner S. B.
Published: April 2012

Phase-field simulations are used to examine the variability of intergranular fission gas bubble growth and percolation on uranium dioxide grain boundaries on a mesoscopic length scale. Three key parameters are systematically varied in this study: the contact angle (or dihedral angle) defining the bubble shape, the initial bubble density on the grain boundary plane, and the ratio of the gas diffusivity on the grain boundary versus the grain interiors. The simulation results agree well with previous experimental data obtained for bubble densities and average bubble areas during coalescence events. Interestingly, the rate of percolation is found to be highly variable, with a large dependency on the contact angle and the initial bubble density and little-to-no dependency on the grain boundary gas diffusivity.
Nanoscale temperature sensing using the Seebeck effect
Authors: Bakker F. L. , Flipse J. , van Wees B. J.
Published: April 2012

We experimentally study the effect of Joule heating on the electron temperature in metallic nanoscale devices and compare the results with a diffusive 3D finite element model. The temperature is probed using four thermocouples located at different distances from the heater. A good quantitative agreement, within 30%, between the experimental data and the modeling is obtained. Since we observe a strong thickness dependence of the electrical conductivity of our metals, we find that the Joule heating in nanoscale devices is often incorrectly calculated if bulk conductivities are used. Furthermore, Peltier heating/cooling is investigated and the combination with Seebeck temperature measurements provides us with a method to determine the Seebeck coefficient of a material.
Conductance oscillation of graphene nanoribbon with tilted p-n junction
Authors: Yang Mou , Ran Xian-Jin , Cui Yan , Wang Rui-Qiang
Published: April 2012

We investigate the transport properties of a graphene nanoribbon with a tilted p-n junction. The conductance versus the Fermi energy shows step structures when the tilt angle is small. For the large tilt angles, the conductance oscillates rapidly with the tilt angle increasing, and the conductance decays non-monotonically with the longitudinal length of the p-n junction area. Based on the subband analysis, we explain these effects by the mix and the interference between different subbands of the ribbon.
Growth and electronic structure of Sm on thin Al2O3/Ni3Al(111) films
Authors: Xu Qian , Hu Shanwei , Cheng Dingling , Feng Xuefei , Han Yong , Zhu Junfa
Published: April 2012

The growth and electronic structure of vapor-deposited Sm on a well-ordered Al2O3/Ni3Al(111) ultrathin film under ultrahigh vacuum conditions at room temperature have been studied comprehensively using synchrotron radiation photoemission spectroscopy, X-ray photoelectron spectroscopy, work function measurements, scanning tunneling microscopy, and low-energy electron diffraction. Our results indicate that at room temperature Sm grows in a layer-by-layer fashion up to at least 1 ML, followed by three-dimensional growth. The interaction of Sm with Al2O3 thin films leads to an initial oxidation of Sm, accompanied by a parallel reduction of the Al2O3 substrate. Both the oxidation states of Sm2+ and Sm3+ are found at low coverage (<1 ML). The concentration of Sm2+ saturates below 0.4 ML, while that of Sm3+ keeps increasing until the metallic state of Sm appears at high coverages.
Evaluation of a reduced-tillering (tin) gene in wheat lines grown across different production environments
Authors: Mitchell J. H. , Chapman S. C. , Rebetzke G. J. , Bonnett D. G. , Fukai S.
Published: April 2012

Post-anthesis water deficit and increasing vapour pressure deficit are common and can result in reduced grain yield and the development of small or shrivelled wheat kernels (screenings) that reduce grain value. Previous studies suggest incorporation of a tiller inhibition (tin) gene to restrict tiller number and thereby slow water use and promote the development of larger, fertile spikes to increase kernel weight. This paper reports on the influence of the tin gene on grain yield and screenings in multiple wheat genetic backgrounds assessed in field experiments in 2005 and 2006. Across environments, grain yield ranged from 0.90 to 5.50 t/ha and screenings from 4 to 20%. The effect of tin on grain yield and screenings varied with environment and genetic background. Grain yield was unchanged in tin lines derived from varieties Brookton, Chara, and Wyalkatchem assessed in southern Australian environments. However, there was a 31 and 10% advantage of free-tillering over tin-containing Silverstar lines for the 2005 western and 2006 northern experiments, respectively, resulting in an average 12% reduction in grain yield of Silverstar tin lines. In northern experiments, where screenings ranged from 4 to 12%, Silverstar-based tin lines produced significantly fewer screenings than free-tillering sister lines. Reduction in screenings was associated with a higher kernel weight (+10%) and a tendency for lower grain yield, although individual Silverstar tin progeny with grain yield equivalent to the parent were readily identified. The incorporation of the tin gene has considerable potential to reduce the incidence of screenings in commercial wheat crops. Variation in grain yield associated with the tin gene was dependent on genetic background, with potential for selection of higher yielding tin progeny for commercial line development.
Octahydriodo diborane (B
2
H
8
) and its protonated cations containing five-, six-, and seven-coordinate boron atoms
Authors: Olah George A. , Surya Prakash G. K. , Rasul Golam
Published: April 2012

Structures of octahydriodo diborane (B
2
H
8
) 1 and its protonated
3
, diprotonated
5
, triprotonated
6
, and tetraprotonated
7
ions were found to be calculationally viable minima at the MP2/cc-pVTZ level of theory. Each structure contains two-electron three-center (2e-3c) bonds. The protonation of
1
to form
3
was found to be strongly exothermic by 176.0 kcal/mol. Subsequent protonation of
3
to form
5
was also found to be exothermic by 28.4 kcal/mol. Further protonation of
5
to form
6
was, however, computed to be endothermic by 122.0 kcal/mol whereas protonation of
6
to form
7
was again highly endothermic by 238.8 kcal/mol. Deprotonation barriers of the ions were also computed.
The impact of self‐confidence on the compromise effect
Authors: Chuang Shih‐Chieh , Cheng Yin‐Hui , Chang Chia‐Jung , Chiang Yu‐Ting
Published: April 2012

This research reports an investigation into whether the personality aspect of self‐confidence affects the compromise effect. We hypothesize that highly self‐confident people have greater certainty in making decisions and are more attracted to risk‐taking, which makes them less likely to choose the safe or middle option in a large choice set. The three studies involved are conducted using between‐ and within‐subjects experimental designs. Various product categories are used to generalize the findings. Study 1 looks at purchasing decisions and utilizes three scales of self‐confidence, risk preference, and uncertainty; it demonstrates that consumers with high self‐confidence are less likely to choose a compromise option due to high certainty in their decision‐making. Study 2 discovers that people with low self‐confidence are more likely to choose the middle option in a risky condition than in a nonrisky condition. Study 3 decomposes self‐confidence into general and specific self‐confidence, and reveals that people with low general self‐confidence and low specific self‐confidence are more likely to choose the middle option.
Evaluative Conditioning without Directly Experienced Pairings of the Conditioned and the Unconditioned Stimuli
Authors: Gast Anne , De Houwer Jan
Published: April 2012

Evaluative conditioning (EC) is the valence change of a stimulus (conditioned stimulus, CS) that is due to the previous pairing with another stimulus (unconditioned stimulus, US). We investigated whether EC can occur also when the CS–US pairings are not experienced directly by the participant but are implied by other events that the participant encounters. In two experiments, positive USs were presented in some trials and negative USs in other trials. Afterwards, participants were given information from which it was possible to conclude that CSs were covertly present during these trials. Finally, the valence of these CSs was registered using both implicit (Implicit Association Test, affective priming) and explicit measures (valence ratings). In line with the assumption that EC effects can be based on CS–US pairings that are not directly experienced, the valence of the CSs changed in the direction of the US with which they were covertly paired. This effect was observed both on explicit and on implicit measures. We argue that several aspects of our results are in line with propositional models of EC and fit less well with association formation models.
Are Preventive and Generative Causal Reasoning Symmetrical? Extinction and Competition
Authors: Baetu Irina , Baker A.G.
Published: April 2012

We tested whether preventive and generative reasoning processes are symmetrical by keeping the training and testing of preventive (inhibitory) and generative (excitatory) causal cues as similar as possible. In Experiment 1, we extinguished excitors and inhibitors in a blocking design, in which each extinguished cause was presented in compound with a novel cause, with the same outcome occurring following the compound and following the novel cause alone. With this novel extinction procedure, the inhibitory cues seemed more likely to lose their properties than the excitatory cues. In Experiment 2, we investigated blocking of excitatory and inhibitory causes and found similar blocking effects. Taken together, these results suggest that acquisition of excitation and inhibition is similar, but that inhibition is more liable to extinguish with our extinction procedure. In addition, we used a variable outcome, and this enabled us to test the predictions of an inferential reasoning account about what happens when the outcome level is at its minimum or maximum (De Houwer, Beckers, & Glautier, 2002). We discuss the predictions of this inferential account, Rescorla and Wagner's (1972) model, and a connectionist model—the auto-associator.
A GENERAL CIRCULATION MODEL FOR GASEOUS EXOPLANETS WITH DOUBLE-GRAY RADIATIVE TRANSFER
Authors: Rauscher Emily , Menou Kristen
Published: April 2012

We present a new version of our code for modeling the atmospheric circulation on gaseous exoplanets, now employing a “double-gray” radiative transfer scheme, which self-consistently solves for fluxes and heating throughout the atmosphere, including the emerging (observable) infrared flux. We separate the radiation into infrared and optical components, each with its own absorption coefficient, and solve standard two-stream radiative transfer equations. We use a constant optical absorption coefficient, while the infrared coefficient can scale as a power law with pressure; however, for simplicity, the results shown in this paper use a constant infrared coefficient. Here we describe our new code in detail and demonstrate its utility by presenting a generic hot Jupiter model. We discuss issues related to modeling the deepest pressures of the atmosphere and describe our use of the diffusion approximation for radiative fluxes at high optical depths. In addition, we present new models using a simple form for magnetic drag on the atmosphere. We calculate emitted thermal phase curves and find that our drag-free model has the brightest region of the atmosphere offset by ∼12° from the substellar point and a minimum flux that is 17% of the maximum, while the model with the strongest magnetic drag has an offset of only ∼2° and a ratio of 13%. Finally, we calculate rates of numerical loss of kinetic energy at ∼15% for every model except for our strong-drag model, where there is no measurable loss; we speculate that this is due to the much decreased wind speeds in that model.
Effects of high-temperature O2 annealing on Al2O3 blocking layer and Al2O3/Si3N4 interface for MANOS structures
Authors: Xu Zhongguang , Zhu Chenxin , Huo Zongliang , Zhao Shengjie , Liu Ming
Published: April 2012

In this paper, we have investigated the effects of O2 post-deposition annealing (PDA) on metal/Al2O3/Si3N4/SiO2/Si (MANOS) devices. Compared with low-energy plasma oxygen pre-treatment and the N2 PDA process, the O2 PDA process can lead to a significant retention improvement. The improvement is attributed to the removal of oxygen vacancies in Al2O3 block oxide and the oxygen incorporation at the Si3N4/Al2O3 interfacial layer which is determined by x-ray photoelectron spectroscopy (XPS) depth profiling and electrical characteristics. Metal/Al2O3/SiO2/Si (MAOS) devices are also studied to confirm these effects. As a result, we consider that the O2 PDA process is a crucial process for future MANOS-type memory devices.
Corrigendum: Spectroscopic investigation of the high-current phase of a pulsed GMAW process
Authors: Rouffet M E , Wendt M , Goett G , Kozakov R , Schoepp H , Weltmann K D , Uhrlandt D
Published: April 2012

The full text of this article is available in the PDF provided.
New Frontiers in Colorectal Cancer Surgery
Authors: Alam Tahsin A. , Qureshi Tas
Published: April 2012

Bowel cancer is a leading cause of cancer-related death in the UK. For many years, treatment of this condition was largely unchanged and involved radical surgery, using long midline incisions and typically requiring a lengthy stay in hospital. In the last few years, there has been a quiet revolution in how patients undergoing surgery for this condition are managed. In this article, we provide an overview on how the introduction of laparoscopic surgery allied with enhanced recovery programmes has resulted in less post-operative pain, earlier return to normal activity and earlier discharge from hospital. We also discuss the increasing role of community health care professionals, and GPs in particular, in supporting these patients both before and after their time in hospital.
A visual environment for the manipulation and integration of JAVA beans.
Authors: Boyle J
Published: April 2012

MOTIVATION: Visual programming has the potential to allow non-programmers to redesign and rebuild applications to suit their individual needs. We have built such a visual programming environment, which allows non-programmers to interrogate and combine software components graphically to form new applications. As the needs of the biological community grow, so too will the need for more powerful and easy to use software tools. Intelligent visual programming environments will allow users to design and develop applications easily, so that they can concentrate on the application they wish to build rather than how it is to be done. RESULTS: The environment can read in JAVA Beans, and present relevant information about the beans to the user. The user can then graphically specify how they would like information to flow between the beans by performing simple docking operations. Unnecessary complexities associated with such visual design have been removed by providing intelligent docking of components and visual feedback. With such mechanisms, the complexities of building new applications are reduced. When the biologist has finished the visual construction, the design system is able to generate the new application automatically. The system has been designed specifically to meet the needs of the biological community, and a range of 'BioBeans' are being developed. These include beans for visualization (sequence displays and data visualizers), analysis (feature recognition, error detection) and communication (database access, URL retrieval, DDE communication). AVAILABILITY: Freely available. CONTACT: boyle@synomics.com
PPCMatrix: a PowerPC dotmatrix program to compare large genomic sequences against protein sequences
Authors: Burglin TR
Published: April 2012

Summary : An interactive dotmatrix program for the MacOS was designed that allows comparison of DNA to protein sequences using nested 3-frame translations. Availability : Shareware, available at http://copan.bioz.unibas.ch/software/ Contact : burglin@ubaclu. unibas.ch
Policosanol Content and Composition of Korean Rice (Oryza sativa L.) Cultivars
Authors: Kim Jae Kwang , Park Soo‐Yun , Jung Ji Yun , Ha Sun‐Hwa , Lim Sun‐Hyung , Lee Si Myung , Woo Hee‐Jong , Park Sang Un , Suh Seok‐Cheol
Published: April 2012

Policosanols (PCs) are a group of long‐chain alcohols that have been reported to have many beneficial physiological activities. In this study, the total content and composition of PCs in 15 rice (Oryza sativa L.) cultivars from Korea were characterized by gas chromatography–time‐of‐flight mass spectrometry. This method proved to be sufficiently precise and accurate with respect to the degree of endogenous biological variability found in the rice samples. Octacosanol (C28) and triacontanol (C30) were the major components of PCs in all cultivars. In addition, there were positive correlations among the determined PC contents. Given its high PC content, the Heughyangbyeo cultivar may appear to be a good candidate for future breeding programs.
Ethylene Signaling Pathway and MAPK Cascades Are Required for AAL Toxin–Induced Programmed Cell Death
Authors: Mase Keisuke , Mizuno Takahito , Ishihama Nobuaki , Fujii Takayuki , Mori Hitoshi , Kodama Motoichiro , Yoshioka Hirofumi
Published: April 2012

Programmed cell death (PCD), known as hypersensitive response cell death, has an important role in plant defense response. The signaling pathway of PCD remains unknown. We employed AAL toxin and Nicotiana umbratica to analysis plant PCD. AAL toxin is a pathogenicity factor of the necrotrophic pathogen Alternaria alternata f. sp. lycopersici. N. umbratica is sensitive to AAL toxin, susceptible to pathogens, and effective in Tobacco rattle virus–based virus-induced gene silencing (VIGS). VIGS analyses indicated that AAL toxin–triggered cell death (ACD) is dependent upon the mitogen-activated protein (MAP) kinase kinase MEK2, which is upstream of both salicylic acid–induced protein kinase (SIPK) and wound-induced protein kinase (WIPK) responsible for ethylene (ET) synthesis. ET treatment of MEK2-silenced N. umbratica re-established ACD. In SIPK- and WIPK-silenced N. umbratica, ACD was compromised and ET accumulation was not observed. However, in contrast to the case of MEK2-silenced plants, ET treatment did not induce cell death in SIPK- and WIPK-silenced plants. This work showed that ET-dependent pathway and MAP kinase cascades are required in ACD. Our results suggested that MEK2-SIPK/WIPK cascades have roles in ET biosynthesis; however, SIPK and WIPK have other roles in ET signaling or another pathway leading to cell death by AAL toxin.
First Report of Tomato Gray Leaf Spot Disease Caused by Stemphylium solani in Malaysia
Authors: Nasehi A. , Kadir J. B. , Abidin M. A. Zainal , Wong M. Y. , Mahmodi F.
Published: April 2012

In June 2011, tomatoes (Solanum lycopersicum) in major growing areas of the Cameron Highlands and the Johor state in Malaysia were affected by a leaf spot disease. Disease incidence exceeded 80% in some severely infected regions. Symptoms on 50 observed plants initially appeared on leaves as small, brownish black specks, which later became grayish brown, angular lesions surrounded by a yellow border. As the lesions matured, the affected leaves dried up and became brittle and later developed cracks in the center of the lesions. A survey was performed in these growing areas and 27 isolates of the pathogen were isolated from the tomato leaves on potato carrot agar (PCA). The isolates were purified by the single spore technique and were transferred onto PCA and V8 agar media for conidiophore and conidia production under alternating light (8 hours per day) and darkness (16 hours per day) (4). Colonies on PCA and V8 agar exhibited grey mycelium and numerous conidia were formed at the terminal end of conidiophores. The conidiophores were up to 240 μm long. Conidia were oblong with 2 to 11 transverse and 1 to 6 longitudinal septa and were 24 to 69.6 μm long × 9.6 to 14.4 μm wide. The pathogen was identified as Stemphylium solani on the basis of morphological criteria (2). In addition, DNA was extracted and the internal transcribed spacer region (ITS) was amplified by universal primers ITS5 and ITS4 (1). The PCR product was purified by the commercial PCR purification kit and the purified PCR product sequenced. The resulting sequences were 100% identical to published S. solani sequences (GenBank Accestion Nos. AF203451 and HQ840713). The amplified ITS region was deposited with NCBI GenBank under Accession No. JQ657726. A representative isolate of the pathogen was inoculated on detached 45-day-old tomato leaves of Malaysian cultivar 152177-A for pathogenicity testing. One wounded and two nonwounded leaflets per leaf were used in this experiment. The leaves were wounded by applying pressure to leaf blades with the serrated edge of a forceps. A 20-μl drop of conidial suspension containing 105 conidia/ml was used to inoculate these leaves (3). The inoculated leaves were placed on moist filter paper in petri dishes and incubated for 48 h at 25°C. Control leaves were inoculated with sterilized distilled water. After 7 days, typical symptoms for S. solani similar to those observed in the farmers' fields developed on both wounded and nonwounded inoculated leaves, but not on noninoculated controls, and S. solani was consistently reisolated. To our knowledge, this is the first report of S. solani causing gray leaf spot of tomato in Malaysia.

References: (1) M. P. S. Camara et al. Mycologia 94:660, 2002. (2) B. S. Kim et al. Plant Pathol. J. 15:348, 1999. (3) B. M. Pryor and T. J. Michailides. Phytopathology 92:406, 2002. (4) E. G. Simmons. CBS Biodiversity Series 6:775, 2007.
Effect of Host Plant, Aphid Species, and Virus Infection Status on Transmission of Sweetpotato feathery mottle virus
Authors: Wosula E. N. , Clark C. A. , Davis J. A.
Published: April 2012

Sweetpotato feathery mottle virus (SPFMV) is a nonpersistently transmitted virus known to infect sweetpotato (Ipomoea batatas) and wild morning glory plants. SPFMV is vectored by various aphid species, among them the green peach aphid, Myzus persicae, and the cotton aphid, Aphis gossypii. Our objective was to determine whether differences in acquisition hosts (sweetpotato and morning glory), aphid species (M. persicae and A. gossypii), and infection status (single versus mixed infection) influenced transmission of SPFMV. SPFMV transmission from I. hederacea with a natural mixed infection by A. gossypii (39%) was significantly greater than in other host–virus combinations. Successful transmissions by A. gossypii were significantly greater compared with M. persicae in all host–virus combinations. Virus titers in source leaves were significantly greater in single- and mixed-infected I. hederacea and single-infected I. cordatotriloba compared with other host–virus combinations. There was a significant positive correlation between virus titer and transmission by both aphid species. These results suggest that, under controlled conditions, SPFMV is more readily transmitted from infected morning glory plants than from sweetpotato. Additionally, mixed-infected plants are better virus sources for transmission than single-infected, and A. gossypii is a more efficient vector than M. persicae under laboratory conditions.