bluuebunny/crossref_metadata_2025 huggingface dataset:
Owners on both sides of the deal: mergers and acquisitions and overlapping institutional ownership
Authors: Goranova Maria , Dharwadkar Ravi , Brandes Pamela
Published: February 2010

Using a corporate governance lens, this study considers owners with a stake in both the acquiring and the target firms in the context of mergers and acquisitions. A possible agency problem arises with regard to monitoring implications as managers may be able to take advantage of compromised monitoring because overlapping owners may focus on the aggregate value for both the acquiring and the target firms and nonoverlapping owners may be interested only in the acquirer's side of the deal. The results suggest that when more owners overlap in their ownership of both the acquiring and target firms, the acquiring firms are more likely to experience decreased shareholder value through merger and acquisition deals. This effect, however, can be constrained by stronger board control. Copyright © 2010 John Wiley & Sons, Ltd.
Do leading or lagging firms learn more from exporting?
Authors: Salomon Robert , Jin Byungchae
Published: February 2010

An interesting theoretical debate arises when considering firm heterogeneity in learning from exporting. One perspective intimates that technologically lagging firms stand to benefit more from exporting because exposure to technological knowledge in foreign markets allows these firms to close the gap with their more technologically endowed counterparts. A contrasting perspective posits that technologically superior firms benefit more from exporting since these firms are better equipped to translate knowledge acquired in foreign markets into innovation. Using a sample of 1,744 Spanish manufacturing firms from 1990–1997, this study empirically investigates how exporting differentially influences the patent output of technologically leading versus technologically lagging firms. We find that exporting is associated with the ex post increase in innovative productivity for both technologically leading and lagging firms. However, subsequent to exporting, technologically leading firms apply for more patents than technologically lagging firms. Copyright © 2010 John Wiley & Sons, Ltd.
Shape Prediction of 3‐D Microstructures Fabricated by PCT Technique and Synchrotron Radiation Lithography
Authors: Horade Mitsuhiro , Sugiyama Susumu
Published: February 2010

We report in this paper simulations for deformed shape predictions of three‐dimensional (3‐D) microstructures fabricated by the plane pattern to cross‐section transfer (PCT) technique and synchrotron radiation (SR) lithography. The investigation of the shape‐prediction system enhances the possibility for higher accuracy of the prediction. In addition, the desired shapes can be confirmed by the shape prediction before designing the mask and running experiments. It is necessary to investigate a variety of error factors to shape prediction. We attempted various investigations. One of the possible causes could be the etching direction, which is dependent on the developing time. Therefore, we currently emphasize on the factor causing this error. In order to comprehend the mechanism of the factor, an algorithm that can simulate development was devised. We have developed a mathematical system of X‐ray energy distribution onto the PMMA (polymethylmethacrylate) resist, and the shape prediction is consequent to the simulations based on calculations from the mathematics software. The mathematical system for energy distribution depends on the SR light source, X‐ray mask specification, and resist specification. As a result, the predicted structures relevant to the absorbed energy–depth–position parameter set and absorbed energy–etching rate parameter set were obtained from this system. This system for shape prediction was implemented by the above parameter sets in C language. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Field‐Dependent Distortion Coefficient and Backward Mapping for Distortion Correction of Singlet Lens Cameras
Authors: Zhang Yupeng , Ueda Toshitsugu
Published: February 2010

This paper introduces approaches to deal with distortion created by a singlet lens camera. Due to the inherent optical defect of singlet lenses, considerable lens aberrations will appear in the resulting image, especially at high field angles. Among the well‐known five monochromatic aberrations and two chromatic aberrations, distortion and blurring are the most obvious aberrations for the designed singlet lens. In this paper, we deal with two techniques for distortion correction: field‐dependent distortion coefficient and backward mapping method. The former will produce more accurate correction than obtained using third‐order coefficient and constant coefficients. The latter does not need additional interpolation process to fill up pixel vacancies and higher precision of pixel values can be obtained compared with our previous forward mapping method. Simulation results indicate the superiority of the proposed two techniques. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Influence of a Measuring System to a Transient Voltage on a Vertical Conductor
Authors: Yutthagowith Peerawut , Ametani Akihiro , Nagaoka Naoto , Baba Yoshihiro
Published: February 2010

This paper studies the effect of a horizontal reference voltage wire, a current lead wire, and the impedance of a voltage probe when measuring a transient voltage on a vertical conductor. A hybrid frequency‐time domain (HFTD) method and a finite‐different time domain (FDTD) method with the help of VSTL are applied to investigate the effect of the horizontal reference voltage wire, the current lead wire, and the impedance of the voltage probe on measurement at the top of the vertical conductor. The obtained results show that the horizontal reference voltage wire perpendicular to the vertical conductor causes a minor effect, but the input capacitance of the voltage probe affects significantly the voltage measurement. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Reagents for investigating MAPK signalling in model yeast species
Authors: Pincus David , Benjamin Kirsten , Burbulis Ian , Tsong Annie E. , Resnekov Orna
Published: February 2010

Here we present a set of resources (bacterial expression plasmids and antibodies) for the interrogation of proteins involved in yeast MAPK signalling. We constructed bacterial protein expression plasmids for 25 proteins involved in MAPK signalling in budding yeast. From these constructs we expressed and purified proteins and generated rabbit polyclonal antibodies against 13 proteins in the pheromone MAPK pathway. We verified the specificity of the antibodies and employed them to follow pathway proteins in cells stimulated with pheromone. We show that these reagents can be used to detect pheromone‐induced post‐translational modifications and changes in the oligomeric state of pathway proteins. In addition to recognizing their target proteins in Saccharomyces cerevisiae, these antibodies allow the detection of predicted orthologues in the distant evolutionary relatives Kluyveromyces lactis and Schizosaccharomyces pombe. These antibodies are new tools for investigating MAPK signalling in model yeast species and may be useful for studying MAPK signalling in higher eukaryotes. Copyright © 2010 John Wiley & Sons, Ltd.
The biochemical basis of hereditary fructose intolerance
Authors: Bouteldja Nadia , Timson David J.
Published: February 2010

Hereditary fructose intolerance is a rare, but potentially lethal, inherited disorder of fructose metabolism, caused by mutation of the aldolase B gene. Treatment currently relies solely on dietary restriction of problematic sugars. Biochemical study of defective aldolase B enzymes is key to revealing the molecular basis of the disease and providing a stronger basis for improved treatment and diagnosis. Such studies have revealed changes in enzyme activity, stability and oligomerisation. However, linking these changes to disease phenotypes has not always been straightforward. This review gives a general overview of the features of hereditary fructose intolerance, then concentrates on the biochemistry of the AP variant (Ala149Pro variant of aldolase B) and molecular pathological consequences of mutation of the aldolase B gene.
Räumliche Regressionsmodelle als leistungsfähige Methoden zur Erklärung der Driving Forces von Zuzügen in der Stadtregion Wien?
Authors: Helbich Marco , J. Görgl Peter
Published: February 2010

In metropolitan regions population development is a continuous and dynamic process and in matters of analyzing it a huge variety of methodical approaches exists. This article introduces the simultaneous autoregressive model and the geographically weighted regression which can be seen as an innovative methodical enhancement of the usual global regression model. Using the urban region of Vienna as case study, the influence of “hard” location factors like land price, accessibilities etc. on in-migration for the period 2004-2006 is analyzed. The explanatory content of the approach as a whole and its additional value will be discussed conclusively, mainly with regard to newer, postsuburban processes in urban regions.
THE CHANGING PLACE OF VISUAL REPRESENTATION IN ECONOMICS: PAUL SAMUELSON BETWEEN PRINCIPLE AND STRATEGY, 1941–1955
Authors: GIRAUD YANN B.
Published: February 2010

In this paper, we show that Paul Samuelson (1915–2009), renowned as one of the main advocates of the mathematization of economics, has also contributed to the change of the place of visual representation in the discipline. In his early works (e.g. Foundations of Economic Analysis published in 1947), he rejected diagrammatic analysis as a relevant tool of theorizing but used diagrams extensively, both as a pedagogic tool in his introductory textbook Economics (1948) and as a way of clarifying his theory of public expenditure (1954-5). We show that Samuelson’s reluctance to use diagrams in his early works can be explained by his training at Chicago and Harvard and his rejecting Marshall’s economics, whereas his adoption of visual language in Economics was a product of the peculiar context affecting American mass-education after WWII. A methodological debate which opposed him to Kenneth Boulding in 1948 led him to reconsider the place of visual representation in order to clarify conceptual controversies during subsequent debates on mathematical economics. Therefore, it can be said that the prominent place of visual language in the diffusion of economic ideas was stabilized in the mid-1950s, as mathematical language became the prevailing tool of economic theorizing. From this, we conclude that the idea that algebra simply upstaged geometry in the making of economic analysis must be qualified.
The unitary spherical spectrum for split classical groups
Authors: Barbasch Dan
Published: February 2010

This paper gives a complete description of the spherical unitary dual of split classical real andp-adic groups. The proof makes heavy use of the affine graded Hecke algebra.
Glacial‐topographic interactions in the Teton Range, Wyoming
Authors: Foster David , Brocklehurst Simon H. , Gawthorpe Rob L.
Published: February 2010

Understanding interactions among tectonics, topography, climate, and erosion is fundamental to studies of mountainous landscapes. Here, we combine topographic analyses with modeled distributions of precipitation, insolation, and flexural isostasy to present a conceptual model of topographic evolution in the Teton Range, Wyoming, and test whether efficient glacial relief production has contributed to summit elevations. The conceptual model reveals a high degree of complexity inherent in even a relatively small, glaciated, mountain range. Back tilting has caused topographic asymmetry, with the greatest relief characterizing eastern catchments in the center of the range. Two high summits, Grand Teton and Mount Moran, rise hundreds of meters above the surrounding landscape; their elevations set by the threshold hillslope angle and the spacing between valleys hosting large, erosionally efficient glaciers. Only basins >20 km2 held glaciers capable of eroding sufficiently rapidly to incise deeply and maintain shallow downvalley gradients on the eastern range flank. Glacial erosion here was promoted by (1) prevailing westerly winds transporting snow to high‐relief eastern basins, leading to cross‐range precipitation asymmetry; (2) the wind‐blown redistribution of snow from open western headwaters into sheltered eastern cirques, with the associated erosion‐driven migration of the drainage divide increasing eastern accumulation areas; and (3) tall, steep hillslopes providing shading, snow influx from avalanching, and insulating debris cover from rockfalls to valley floor glaciers. In comparison, the topographic enhancement of glacial erosion was less pronounced in western, and smaller eastern, basins. Despite dramatic relief production, insufficient rock mass is removed from the Teton Range to isostatically raise summit elevations.
An unusual VLF signature structure recorded by the DEMETER satellite
Authors: Ferencz Csaba , Lichtenberger János , Hamar Dániel , Ferencz Orsolya E. , Steinbach Péter , Székely Balázs , Parrot Michel , Lefeuvre François , Berthelier Jean‐Jacques , Clilverd Mark
Published: February 2010

A type of electromagnetic phenomenon has been found in the electric VLF data measured by the low Earth orbit DEMETER satellite, which was nonidentified earlier as a different class of electromagnetic VLF events. The phenomenon, termed as “swallow‐tailed whistler” (STW) after its shape, seems to be similar to a whistler, but following the main trace, an additional trace appears with monotonously increasing frequency. The secondary trace, lasting less than 80 ms within the recorded 20 kHz bandwidth joins at a given Starting Furcation Frequency. In a 7 month long time interval three series of strong STWs were found in a geographically confined search zone. Further, 10 weak STW periods have been identified by a thorough review of a 2 month long recording. Several STWs were found by the investigation of randomly selected DEMETER burst VLF recording acquired globally. On the basis of comparisons with previous studies, we can exclude that this phenomenon is generated by plasma processes in the vicinity of the satellite though the formation mechanism of this (ionospheric) signal is so far unclear. It is possible that this event type appeared in earlier records too, however, without identification.
Lithospheric thinning and localization of deformation during Rayleigh‐Taylor instability with nonlinear rheology and implications for intracontinental magmatism
Authors: Harig Christopher , Molnar Peter , Houseman Gregory A.
Published: February 2010

Thinning of mantle lithosphere due to Rayleigh‐Taylor instability can be a mechanism for triggering continental magmatism near active or recently active plate boundaries. We consider whether it is also plausible as a mechanism for intracontinental magmatism, several hundred kilometers from active subduction or rifting. We perform two‐dimensional Rayleigh‐Taylor experiments and find that a shear stress‐free top and non‐Newtonian flow permit two types of instability to develop, largely dependent on how the viscosity coefficient varies with depth. For small variation with depth, with the e‐folding depth scale (the interval across which the coefficient changes by a factor of e) greater than a third to a half of the thickness of the unstable layer, deformation concentrates at the ends of the layer in localized thinning and thickening zones; the middle part moves horizontally toward the region of thickening as a coherent block undergoing minimal strain. When the viscosity coefficient decreases more rapidly with depth, thinning of the layer is distributed laterally over a wide zone. Between the regions of thickening and thinning, shear strain and vertical gradients in horizontal velocity prevent this area from moving as a coherent block. The rheological exponent, n, that relates strain rate to stress in the constitutive equation controls the degree of localization of the downwelling and upwelling: the width varies as ≈n−1/2. In intraplate settings where a shear stress‐free top condition could be applicable, high‐stress crystalline plasticity could provide a mechanism for the narrow zones of thinning and upwelling, which would facilitate decompression related volcanism.
Understanding biogeobatteries: Where geophysics meets microbiology
Authors: Revil A. , Mendonça C. A. , Atekwana E. A. , Kulessa B. , Hubbard S. S. , Bohlen K. J.
Published: February 2010

Although recent research suggests that contaminant plumes behave as geobatteries that produce an electrical current in the ground, no associated model exists that honors both geophysical and biogeochemical constraints. Here, we develop such a model to explain the two main electrochemical contributions to self‐potential signals in contaminated areas. Both contributions are associated with the gradient of the activity of two types of charge carriers, ions and electrons. In the case of electrons, bacteria act as catalysts for reducing the activation energy needed to exchange the electrons between electron donors and electron acceptors. Possible mechanisms that facilitate electron migration include iron oxides, clays, and conductive biological materials, such as bacterial conductive pili or other conductive extracellular polymeric substances. Because we explicitly consider the role of biotic processes in the geobattery model, we coined the term “biogeobattery.” After theoretical development of the biogeobattery model, we compare model predictions with self‐potential responses associated with laboratory and field scale investigations conducted in contaminated environments. We demonstrate that the amplitude and polarity of large (>100 mV) self‐potential signatures requires the presence of an electronic conductor to serve as a bridge between electron donors and acceptors. Small self‐potential anomalies imply that electron donors and electron acceptors are not directly interconnected, but instead result simply from the gradient of the activity of the ionic species that are present in the system.
Terrestrial Cosmogenic Nuclide Geochronology Data Reporting Standards Needed
Authors: Frankel Kurt L. , Finkel Robert C. , Owen Lewis A.
Published: February 2010

Scientists can estimate the time at which rocks at Earth's surface became exposed (through glacial scour, faulting, sediment deposition, exhumation, etc.) in a given area using terrestrial cosmogenic nuclide (TCN) geochronology. The idea behind this technique is ingenious in its simplicity. Imagine, for example, a glacier advancing over the landscape and scouring the rocks underneath. As the glacier retreats, fresh rock surfaces become exposed to the atmosphere. Galactic cosmic rays then bombard the fresh minerals exposed at the Earth's surface, producing rare nuclides such as beryllium‐10 (10Be) and aluminum‐26 (26Al) in the process. Thus, measuring the concentration of TCNs in rocks at the Earth's surface allows scientists to estimate how long a surface has been exposed and/or the rate of surface denudation.
Different sets of QTLs influence fitness variation in yeast
Authors: Romano Gal Hagit , Gurvich Yonat , Lavi Ofer , Ulitsky Igor , Shamir Ron , Kupiec Martin
Published: February 2010

Most of the phenotypes in nature are complex and are determined by many quantitative trait loci (QTLs). In this study we identify gene sets that contribute to one important complex trait: the ability of yeast cells to survive under alkali stress. We carried out an in‐lab evolution (ILE) experiment, in which we grew yeast populations under increasing alkali stress to enrich for beneficial mutations. The populations acquired different sets of affecting alleles, showing that evolution can provide alternative solutions to the same challenge. We measured the contribution of each allele to the phenotype. The sum of the effects of the QTLs was larger than the difference between the ancestor phenotype and the evolved strains, suggesting epistatic interactions between the QTLs. In parallel, a clinical isolated strain was used to map natural QTLs affecting growth at high pH. In all, 17 candidate regions were found. Using a predictive algorithm based on the distances in protein‐interaction networks, candidate genes were defined and validated by gene disruption. Many of the QTLs found by both methods are not directly implied in pH homeostasis but have more general, and often regulatory, roles.
Revealing a signaling role of phytosphingosine‐1‐phosphate in yeast
Authors: Cowart L Ashley , Shotwell Matthew , Worley Mitchell L , Richards Adam J , Montefusco David J , Hannun Yusuf A , Lu Xinghua
Published: February 2010

Sphingolipids including sphingosine‐1‐phosphate and ceramide participate in numerous cell programs through signaling mechanisms. This class of lipids has important functions in stress responses; however, determining which sphingolipid mediates specific events has remained encumbered by the numerous metabolic interconnections of sphingolipids, such that modulating a specific lipid of interest through manipulating metabolic enzymes causes ‘ripple effects’, which change levels of many other lipids. Here, we develop a method of integrative analysis for genomic, transcriptomic, and lipidomic data to address this previously intractable problem. This method revealed a specific signaling role for phytosphingosine‐1‐phosphate, a lipid with no previously defined specific function in yeast, in regulating genes required for mitochondrial respiration through the HAP complex transcription factor. This approach could be applied to extract meaningful biological information from a similar experimental design that produces multiple sets of high‐throughput data.
Ecological, phenological and biochemical significance of bimodal fruiting of Boletus alutaceus morgan
Authors: Kamat Nandkumar
Published: February 2010

Boletus alutaceus Morgan an ectomycorrhizal species was extensively studied from an ecologically fragmented microhabitt colonized by its' host plant Ficus benghalensis L. in the Goa University campus, Taleigao, Goa, India. Qualitatively the fruiting cycles were monitored for three years and thereafter detail ecological and morphological investigations were carried out in May and November 2004. A bimodal temporal fruting pattern emerged which may have significant ecological, phenological and biochemical role in EM dynamics.
First results from the new RIKEN superconducting electron cyclotron resonance ion source (invited)
Authors: Nakagawa T. , Higurashi Y. , Ohnishi J. , Aihara T. , Tamura M. , Uchiyama A. , Okuno H. , Kusaka K. , Kidera M. , Ikezawa E. , Fujimaki M. , Sato Y. , Watanabe Y. , Komiyama M. , Kase M. , Goto A. , Kamigaito O. , Yano Y.
Published: February 2010

The next generation heavy ion accelerator facility, such as the RIKEN radio isotope (RI) beam factory, requires an intense beam of high charged heavy ions. In the past decade, performance of the electron cyclotron resonance (ECR) ion sources has been dramatically improved with increasing the magnetic field and rf frequency to enhance the density and confinement time of plasma. Furthermore, the effects of the key parameters (magnetic field configuration, gas pressure, etc.) on the ECR plasma have been revealed. Such basic studies give us how to optimize the ion source structure. Based on these studies and modern superconducting (SC) technology, we successfully constructed the new 28 GHz SC-ECRIS, which has a flexible magnetic field configuration to enlarge the ECR zone and to optimize the field gradient at ECR point. Using it, we investigated the effect of ECR zone size, magnetic field configuration, and biased disk on the beam intensity of the highly charged heavy ions with 18 GHz microwaves. In this article, we present the structure of the ion source and first experimental results with 18 GHz microwave in detail.
van der Waals adhesion of graphene membranes
Authors: Lu Zhixing , Dunn Martin L.
Published: February 2010

We study the nanomechanics of graphene and other ultrathin membranes adhered to substrates with open cavities by van der Waals forces, and subjected to mechanical loads (concentrated or pressure) that cause stretching, decohesion, and/or sliding. We develop analytical models to describe equilibrium configurations similar to those observed in recent nanomechanical experiments, as well as various deformation regimes that occur upon mechanical loading. We apply the analytical models to single layers of graphene and carry out atomistic simulations of graphene adhered to a substrate to validate the models and illustrate the operative phenomena. We obtain excellent agreement between theory and atomistic simulations and identify the influence of van der Waals adhesion energy, membrane elasticity, geometry, and loading on membrane decohesion from and/or sliding along a substrate.
Comparison of the performance of photonic band-edge liquid crystal lasers using different dyes as the gain medium
Authors: Mowatt Carrie , Morris Stephen M. , Song Myoung Hoon , Wilkinson Timothy D. , Friend Richard H. , Coles Harry J.
Published: February 2010

The primary concern of this work is to study the emission characteristics of a series of chiral nematic liquid crystal lasers doped with different laser dyes (DCM, pyrromethene 580, and pyrromethene 597) at varying concentrations by weight (0.5–2 wt %) when optically pumped at 532 nm. Long-wavelength photonic band-edge laser emission is characterized in terms of threshold energy and slope efficiency. At every dye concentration investigated, the pyrromethene 597-doped lasers exhibit the highest slope efficiency (ranging from 15% to 32%) and the DCM-doped lasers the lowest (ranging from 5% to 13%). Similarly, the threshold was found to be, in general, higher for the DCM-doped laser samples in comparison to the pyrromethene-doped laser samples. These results are then compared with the spectral properties, quantum efficiencies and, where possible, fluorescence lifetimes of the dyes dispersed in a common nematic host. In accordance with the low thresholds and high slope efficiencies, the results show that the molar extinction coefficients and quantum efficiencies are considerably larger for the pyrromethene dyes in comparison to DCM, when dispersed in the liquid crystal host.
Ferromagnetism in Ge/SiO2 multilayer films
Authors: Zhen Congmian , Liu Yuanbo , Ma Li , Pang Zhaoguang , Pan Chengfu , Hou Denglu
Published: February 2010

The onset of room-temperature (RT) ferromagnetism (FM) has been experimentally observed in amorphous Ge/SiO2 multilayer films. Both the thickness of the individual layers of SiO2 and that of the Ge layers can influence the ferromagnetic order of the samples. The saturation magnetization (MS) reached a maximum of 18.3 emu/cm3 at RT for the film with structure [Ge(5 nm)/SiO2(8 nm)]3. The zero-field-cooled and field-cooled curves for the film show the coexistence of ferromagnetic and diamagnetic components. Obvious magnetic domains were observed in all of the samples. Ge forms mainly Ge–Ge bonds. In addition, Photoluminescence from interband indirect recombination and transitions between discrete energy levels in Ge nanostructures were observed. The FM in the Ge/SiO2 multilayer films can be attributed to both the quantum size effect and coupling of unpaired spins among the Ge nanostructures. The coupling tends to make the unpaired spins align in a ferromagnetic manner.
Multireference study of spin-orbit coupling in the hydrides of the 6p-block elements using the model core potential method
Authors: Zeng Tao , Fedorov Dmitri G. , Klobukowski Mariusz
Published: February 2010

Careful spin-orbit multireference studies were carried out for the late p-block elements Tl, Pb, Bi, Po, At, and Rn and their hydrides using the model core potentials developed in the present work. The model core potentials were designed to treat the scalar-relativistic and spin-orbit coupling effects at the Douglas–Kroll level. The variational stability of the spin-orbit coupling operator was discussed in terms of the relativistic kinematic operators and depicted graphically. A detailed analysis of the spin-orbit multireference dissociation curves of the 6p element hydrides as well as of their atomic spectra allowed to establish the accuracy of the model core potentials with respect to all-electron calculations to be within several mÅ for re, meV (ceV) for De at the correlation level of configuration interaction (multireference perturbation theory), 30 cm−1 for ωe, and about 350 cm−1 for the low-lying atomic and molecular term and level energies. These values are expected to be the maximum error limits for the model core potentials of all the np-block elements (n=2–6). Furthermore, a good agreement with experiment requires that many terms be coupled in the spin-orbit coupling calculations. A timing study of Tl and TlH computations indicates that the model core potentials lead to 20-fold (6-fold) speedup at the level of configuration interaction (multireference perturbation theory) calculations.
Three-dimensional photovoltaics
Authors: Myers Bryan , Bernardi Marco , Grossman Jeffrey C.
Published: February 2010

The concept of three-dimensional (3D) photovoltaics is explored computationally using a genetic algorithm to optimize the energy production in a day for arbitrarily shaped 3D solar cells confined to a given area footprint and total volume. Our simulations demonstrate that the performance of 3D photovoltaic structures scales linearly with height, leading to volumetric energy conversion, and provides power fairly evenly throughout the day. Furthermore, we show that optimal 3D structures are not simple box-like shapes, and that design attributes such as reflectivity could be optimized using three-dimensionality.
Improved piezoelectric actuators for use in high-speed pulsed valves
Authors: Proctor David L. , Albert Daniel R. , Davis H. Floyd
Published: February 2010

We describe the assembly of piezoelectric actuators suitable for use in Proch–Trickl pulsed gas valves employed in pulsed molecular beam experiments. In their simplest form, these actuators have performance equal to and resistance to chemical attack far superior to the recently discontinued commercial actuator around which the valve was originally designed. New actuators have been designed employing several different dual piezo configurations. The dual piezo design reliably produces shorter pulses than the original actuator, resulting in reduced gas consumption and lower average source chamber pressures for a given backing pressure and pulse rate. By electrically isolating the actuator assembly, active adjustment of the closed position may be achieved by simple addition of a continuous voltage bias.
The diffusive finite state projection algorithm for efficient simulation of the stochastic reaction-diffusion master equation
Authors: Drawert Brian , Lawson Michael J. , Petzold Linda , Khammash Mustafa
Published: February 2010

We have developed a computational framework for accurate and efficient simulation of stochastic spatially inhomogeneous biochemical systems. The new computational method employs a fractional step hybrid strategy. A novel formulation of the finite state projection (FSP) method, called the diffusive FSP method, is introduced for the efficient and accurate simulation of diffusive transport. Reactions are handled by the stochastic simulation algorithm.
The cubic to tetragonal phase transition in SrTiO3 single crystals near its surface under internal and external strains
Authors: Loetzsch R. , Lübcke A. , Uschmann I. , Förster E. , Große V. , Thuerk M. , Koettig T. , Schmidl F. , Seidel P.
Published: February 2010

The displacive phase transition in SrTiO3 was investigated by means of x-ray diffraction. We used 4.5 keV photons thus probing only a very thin region near the surface. In the low temperature phase the lattice parameters evolve substantially different than in bulk material. We also investigated the phase transition under the influence of an epitaxial coating with YBaCu2O7 and found the nature of the phase transition changed. The near-surface region behaves like an epitaxial thin SrTiO3 film.
“Spit and Sing, My Yugoslavia”: New Partisans, social critique and Bosnian poetics of the patriotic
Authors: Mišina Dalibor
Published: February 2010

As “music of commitment,” in the period from the late 1970s to the late 1980s rock music in Yugoslavia had an important purpose of providing a popular-cultural outlet for the unique forms of socio-cultural critique that engaged with the realities and problems of Yugoslav society. The three “music movements” that embodied the new rock'n'roll spirit – New Wave, New Primitives, and New Partisans – used rock music to critique the country's “new socialist culture,” with the purpose of helping to eliminate the disconnect between the ideal and the reality of socialist Yugoslavia. This paper examines the New Partisans as the most radical expression of music of commitment through the works of its most important rock bands: Bijelo dugme, Plavi orkestar, and Merlin. The paper's argument is that the New Partisans’ socio-cultural engagement, animated by advocacy of Yugoslavism, was a counter-logic to the nationalist dissolution of a distinctly Yugoslav fabric of a socialist community in crisis. Thus, the movement's revolutionary “spirit of reconstruction” permeating its “poetics of the patriotic” was a mechanism of socio-cultural resistance to political, cultural and moral-ethical de-Yugoslavization of Yugoslav society. Its ultimate objective was to make the case that the only way into the future – if there was to be any – rested on strategic reanimation of the Partisan revolutionary past as the only viable socio-cultural foundation of the Yugoslav socialist community.
Yugoslavism between the world wars: indecisive nation building
Authors: Troch Pieter
Published: February 2010

This article examines Yugoslav national programs of ruling political elites and its concrete implementation in education policy in interwar Yugoslavia. It is argued that at the beginning of the period Yugoslavism was not inherently incompatible with or subordinate to Serbian, Croatian or to a lesser degree Slovenian national ideas. However, the concrete ways in which Yugoslavism was formulated and adopted by ruling elites discredited the Yugoslav national idea and resulted in increasing delineation and polarization in the continuum of national ideas available in Yugoslavia. Throughout the three consecutive periods of political rule under scrutiny, ruling elites failed to reach a wider consensus regarding the Yugoslav national idea or to create a framework within which a constructive elaboration of Yugoslav national identity could take place. By the end of the interwar period, the Yugoslav national idea had become linked exclusively to conservatism, centralism, authoritarianism and, for non-Serbian elites at least, Serbian hegemony. Other national ideas gained significance as ideas providing viable alternatives for the regime's Yugoslavism.
Amiloride inhibits macropinocytosis by lowering submembranous pH and preventing Rac1 and Cdc42 signaling
Authors: Koivusalo Mirkka , Welch Christopher , Hayashi Hisayoshi , Scott Cameron C. , Kim Moshe , Alexander Todd , Touret Nicolas , Hahn Klaus M. , Grinstein Sergio
Published: February 2010

Macropinocytosis is differentiated from other types of endocytosis by its unique susceptibility to inhibitors of Na+/H+ exchange. Yet, the functional relationship between Na+/H+ exchange and macropinosome formation remains obscure. In A431 cells, stimulation by EGF simultaneously activated macropinocytosis and Na+/H+ exchange, elevating cytosolic pH and stimulating Na+ influx. Remarkably, although inhibition of Na+/H+ exchange by amiloride or HOE-694 obliterated macropinocytosis, neither cytosolic alkalinization nor Na+ influx were required. Instead, using novel probes of submembranous pH, we detected the accumulation of metabolically generated acid at sites of macropinocytosis, an effect counteracted by Na+/H+ exchange and greatly magnified when amiloride or HOE-694 were present. The acidification observed in the presence of the inhibitors did not alter receptor engagement or phosphorylation, nor did it significantly depress phosphatidylinositol-3-kinase stimulation. However, activation of the GTPases that promote actin remodelling was found to be exquisitely sensitive to the submembranous pH. This sensitivity confers to macropinocytosis its unique susceptibility to inhibitors of Na+/H+ exchange.
Unconventional secretion of Acb1 is mediated by autophagosomes
Authors: Duran Juan M. , Anjard Christophe , Stefan Chris , Loomis William F. , Malhotra Vivek
Published: February 2010

Starving Dictyostelium discoideum cells secrete AcbA, an acyl coenzyme A–binding protein (ACBP) that lacks a conventional signal sequence for entering the endoplasmic reticulum (ER). Secretion of AcbA in D. discoideum requires the Golgi-associated protein GRASP. In this study, we report that starvation-induced secretion of Acb1, the Saccharomyces cerevisiae ACBP orthologue, also requires GRASP (Grh1). This highlights the conserved function of GRASP in unconventional secretion. Although genes required for ER to Golgi or Golgi to cell surface transport are not required for Acb1 secretion in yeast, this process involves autophagy genes and the plasma membrane t-SNARE, Sso1. Inhibiting transport to vacuoles does not affect Acb1 secretion. In sum, our experiments reveal a unique secretory pathway where autophagosomes containing Acb1 evade fusion with the vacuole to prevent cargo degradation. We propose that these autophagosome intermediates fuse with recycling endosomes instead to form multivesicular body carriers that then fuse with the plasma membrane to release cargo.
Unconventional secretion by autophagosome exocytosis
Authors: Pfeffer Suzanne R.
Published: February 2010

In this issue, Duran et al. (2010. J. Cell Biol. doi: 10.1083/jcb.200911154) and Manjithaya et al. (2010. J. Cell Biol. doi: 10.1083/jcb.200911149) use yeast genetics to reveal a role for autophagosome intermediates in the unconventional secretion of an acyl coenzyme A (CoA)–binding protein that lacks an endoplasmic reticulum signal sequence. Medium-chain acyl CoAs are also required and may be important for substrate routing to this pathway.
Non-doped white organic light-emitting diodes based on aggregation-induced emission
Authors: Chen Shuming , Zhao Zujin , Tang Ben Zhong , Kwok Hoi Sing
Published: February 2010

Non-doped white organic light-emitting diodes (WOLEDs) based on newly synthesized bluish-green light-emitting material 1,3,6,8-tetrakis [4-(1,2,2-triphenylvinyl)phenyl]pyrene (TTPEPy) and red light-emitting material 4-(4-(1,2,2-triphenylvinyl)phenyl)-7-(5-(4-(1,2,2-triphenylvinyl)phenyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole (BTPETTD) have been demonstrated. A maximum efficiency of 7.4 cd A−1, 4 lm W−1 and brightness of 18 000 cd m−2 have been achieved by employing 3 nm thick 4, 4′-bis [N-(1-naphthyl-1-)-N-phenyl-amino]- biphenyl (NPB) as an electron-blocking layer. The WOLEDs exhibit a high colour rendering index of 90 and moderate colour stability with 1931 Commision International de L'Eclairage coordinates changing from (0.41, 0.41) to (0.38, 0.40) over a wide range of driving voltages. Moreover, the non-doped WOLEDs enjoy a reduced efficiency roll-off due to their nature of aggregation-induced emission.
Investigation of discharge mechanisms in helium plasma jet at atmospheric pressure by laser spectroscopic measurements
Authors: Urabe Keiichiro , Morita Tadasuke , Tachibana Kunihide , Ganguly Biswa N
Published: February 2010

We have measured spatiotemporal structures of excited species by laser spectroscopic methods in a plasma jet, which was driven by a bipolar impulse voltage pulse train of the order of kilohertz repetition rate applied across a pair of electrodes wrapped around a glass tube with a helium gas flow. We noticed the differences between the positive and the negative phases of the voltage applied to the front-side electrode placed closer to the tube exit while the back-side electrode was grounded. The experimental results showed that the radial distribution of the excited species had a hollow shape at the centre in the positive voltage phase, while it had a more uniform shape in the negative phase. The peak density of the helium metastable atom in the positive phase was almost constant irrespective of the peak applied voltage. However, it increased with the increase in the peak applied voltage in the negative phase. The mechanism causing these differences was argued from the respects of positive and negative corona discharges. We have also investigated the property of the plasma plume under conditions similar to material processing with a conductive substrate placed in front of the plasma jet. In this case, the plasma production by electron impact ionization became dominant near the substrate as was revealed from the spatiotemporal distributions of helium metastable atom and nitrogen ion densities.
Photophysical studies of poly-isocyanopeptide based photovoltaic blends
Authors: Finlayson C E , Whitney A D
Published: February 2010

We report a photophysical study of photovoltaic blends containing perylene-substituted polyisocyanide (pery-PIC) materials, using time-correlated single photon counting and photo-induced absorption spectroscopy, and compare the key characteristics with analogous perylene-diimide (PDI) monomer blends with polythiophene- and polyfluorene-based conjugated polymers. Pery-PIC consists of semiconducting perylene units, which self-stack in a regular fashion around a rigid helical poly-isocyanopeptide backbone. In particular, the charged state lifetimes in pery-PIC blends are found to be of order tens of microseconds, this being typically less than half those of the perylene anion in the corresponding PDI blends. We consider the influence of photophysical factors on the superior photovoltaic device performance of the pery-PIC blends, relative to the corresponding PDI-based devices, in addition to the morphological effects described in earlier studies.
iPHACE: integrative navigation in pharmacological space
Authors: Garcia-Serna Ricard , Ursu Oleg , Oprea Tudor I. , Mestres Jordi
Published: February 2010

Summary: The increasing availability of experimentally determined binding affinities for drugs on multiple protein targets requires the design of specific mining and visualization tools that graphically integrate chemical and biological data in an efficient environment. With this aim, we developed iPHACE, an integrative web-based tool to navigate in the pharmacological space defined by small molecule drugs contained in the IUPHAR-DB, with additional interactions present in PDSP. Extending beyond traditional querying and filtering tools, iPHACE offers a means to extract knowledge from the target profile of drugs as well as from the drug profile of protein targets.

Availability: iPHACE is available at http://cgl.imim.es/iphace/ (EU site) and http://agave.health.unm.edu/iphace/ (US mirror)

Contact:  jmestres@imim.es
Generalized empirical likelihood methods for analyzing longitudinal data
Authors: Wang Suojin , Qian Lianfen , Carroll Raymond J.
Published: February 2010

Efficient estimation of parameters is a major objective in analyzing longitudinal data. We propose two generalized empirical likelihood-based methods that take into consideration within-subject correlations. A nonparametric version of the Wilks theorem for the limiting distributions of the empirical likelihood ratios is derived. It is shown that one of the proposed methods is locally efficient among a class of within-subject variance-covariance matrices. A simulation study is conducted to investigate the finite sample properties of the proposed methods and compares them with the block empirical likelihood method by You et al. (2006) and the normal approximation with a correctly estimated variance-covariance. The results suggest that the proposed methods are generally more efficient than existing methods that ignore the correlation structure, and are better in coverage compared to the normal approximation with correctly specified within-subject correlation. An application illustrating our methods and supporting the simulation study results is presented.
Essential role of Tip60-dependent recruitment of ribonucleotide reductase at DNA damage sites in DNA repair during G1 phase
Authors: Niida Hiroyuki , Katsuno Yuko , Sengoku Misuzu , Shimada Midori , Yukawa Megumi , Ikura Masae , Ikura Tsuyoshi , Kohno Kazuteru , Shima Hiroki , Suzuki Hidekazu , Tashiro Satoshi , Nakanishi Makoto
Published: February 2010

A balanced deoxyribonucleotide (dNTP) supply is essential for DNA repair. Here, we found that ribonucleotide reductase (RNR) subunits RRM1 and RRM2 accumulated very rapidly at damage sites. RRM1 bound physically to Tip60. Chromatin immunoprecipitation analyses of cells with an I-SceI cassette revealed that RRM1 bound to a damage site in a Tip60-dependent manner. Active RRM1 mutants lacking Tip60 binding failed to rescue an impaired DNA repair in RRM1-depleted G1-phase cells. Inhibition of RNR recruitment by an RRM1 C-terminal fragment sensitized cells to DNA damage. We propose that Tip60-dependent recruitment of RNR plays an essential role in dNTP supply for DNA repair.
A highly coordinated cell wall degradation machine governs spore morphogenesis in Bacillus subtilis
Authors: Morlot Cecile , Uehara Tsuyoshi , Marquis Kathleen A. , Bernhardt Thomas G. , Rudner David Z.
Published: February 2010

How proteins catalyze morphogenesis is an outstanding question in developmental biology. In bacteria, morphogenesis is intimately linked to remodeling the cell wall exoskeleton. Here, we investigate the mechanisms by which the mother cell engulfs the prospective spore during sporulation in Bacillus subtilis. A membrane-anchored protein complex containing two cell wall hydrolases plays a central role in this morphological process. We demonstrate that one of the proteins (SpoIIP) has both amidase and endopeptidase activities, such that it removes the stem peptides from the cell wall and cleaves the cross-links between them. We further show that the other protein (SpoIID) is the founding member of a new family of lytic transglycosylases that degrades the glycan strands of the peptidoglycan into disaccharide units. Importantly, we show that SpoIID binds the cell wall, but will only cleave the glycan strands after the stem peptides have been removed. Finally, we demonstrate that SpoIID also functions as an enhancer of SpoIIP activity. Thus, this membrane-anchored enzyme complex is endowed with complementary, sequential, and stimulatory activities. These activities provide a mechanism for processive cell wall degradation, supporting a model in which circumferentially distributed degradation machines function as motors pulling the mother cell membranes around the forespore.