bluuebunny/crossref_metadata_2025 huggingface dataset:
Common source outbreaks of Campylobacter infection in the USA, 1997–2008
Authors: TAYLOR E. V. , HERMAN K. M. , AILES E. C. , FITZGERALD C. , YODER J. S. , MAHON B. E. , TAUXE R. V.
Published: August 2012

Campylobacter is a common but decreasing cause of foodborne infections in the USA. Outbreaks are uncommon and have historically differed from sporadic cases in seasonality and contamination source. We reviewed reported outbreaks of campylobacteriosis. From 1997 to 2008, 262 outbreaks were reported, with 9135 illnesses, 159 hospitalizations, and three deaths. The annual mean was 16 outbreaks for 1997–2002, and 28 outbreaks for 2003–2008. Almost half occurred in warmer months. Foodborne transmission was reported in 225 (86%) outbreaks, water in 24 (9%), and animal contact in seven (3%). Dairy products were implicated in 65 (29%) foodborne outbreaks, poultry in 25 (11%), and produce in 12 (5%). Reported outbreaks increased during a period of declining overall incidence, and seasonality of outbreaks resembled that of sporadic infections. Unlike sporadic illnesses, which are primarily attributed to poultry, dairy products are the most common vehicle identified for outbreaks.
Developing a new syndromic surveillance system for the London 2012 Olympic and Paralympic Games
Authors: HARCOURT S. E. , FLETCHER J. , LOVERIDGE P. , BAINS A. , MORBEY R. , YEATES A. , McCLOSKEY B. , SMYTH B. , IBBOTSON S. , SMITH G. E. , ELLIOT A. J.
Published: August 2012

Syndromic surveillance is vital for monitoring public health during mass gatherings. The London 2012 Olympic and Paralympic Games represents a major challenge to health protection services and community surveillance. In response to this challenge the Health Protection Agency has developed a new syndromic surveillance system that monitors daily general practitioner out-of-hours and unscheduled care attendances. This new national system will fill a gap identified in the existing general practice-based syndromic surveillance systems by providing surveillance capability of general practice activity during evenings/nights, over weekends and public holidays. The system will complement and supplement the existing tele-health phone line, general practitioner and emergency department syndromic surveillance systems. This new national system will contribute to improving public health reassurance, especially to meet the challenges of the London 2012 Olympic and Paralympic Games.
Microbiological aspects of public health planning and preparedness for the 2012 Olympic Games
Authors: MORAN-GILAD J. , CHAND M. , BROWN C. , SHETTY N. , MORRIS G. , GREEN J. , JENKINS C. , LING C. , McLAUCHLIN J. , HARRISON T. , GODDARD N. , BROWN K. , BOLTON F. J. , ZAMBON M.
Published: August 2012

Although communicable diseases have hitherto played a small part in illness associated with Olympic Games, an outbreak of infection in a national team, Games venue or visiting spectators has the potential to disrupt a global sporting event and distract from the international celebration of athletic excellence. Preparation for hosting the Olympic Games includes implementation of early warning systems for detecting emerging infection problems. Ensuring capability for rapid microbiological diagnoses to inform situational risk assessments underpins the ability to dispel rumours. These are a prelude to control measures to minimize impact of any outbreak of infectious disease at a time of intense public scrutiny. Complex multidisciplinary teamwork combined with laboratory technical innovation and efficient information flows underlie the Health Protection Agency's preparation for the London 2012 Olympic and Paralympic Games. These will deliver durable legacies for clinical and public health microbiology, outbreak investigation and control in the coming years.
Editorial
Authors: ACAR UMUT A. , CHENEY JAMES , WEIRICH STEPHANIE
Published: August 2012

The 15th ACM SIGPLAN International Conference on Functional Programming (ICFP) took place on September 27–29, 2010 in Baltimore, Maryland. After the conference, the programme committee, chaired by Stephanie Weirich, selected several outstanding papers and invited their authors to submit to this special issue of Journal of Functional Programming. Umut A. Acar and James Cheney acted as editors for these submissions. This issue includes the seven accepted papers, each of which provides substantial new material beyond the original conference version. The selected papers reflect a consensus by the program committee that ICFP 2010 had a number of strong papers that link core functional programming ideas with other areas, such as multicore, embedded systems, and data compression.
ITERATIVE SOLUTION OF SHIFTED POSITIVE-DEFINITE LINEAR SYSTEMS ARISING IN A NUMERICAL METHOD FOR THE HEAT EQUATION BASED ON LAPLACE TRANSFORMATION AND QUADRATURE
Authors: MCLEAN WILLIAM , THOMÉE VIDAR
Published: August 2012

In earlier work we have studied a method for discretization in time of a parabolic problem, which consists of representing the exact solution as an integral in the complex plane and then applying a quadrature formula to this integral. In application to a spatially semidiscrete finite-element version of the parabolic problem, at each quadrature point one then needs to solve a linear algebraic system having a positive-definite matrix with a complex shift. We study iterative methods for such systems, considering the basic and preconditioned versions of first the Richardson algorithm and then a conjugate gradient method.
Redescription of the lungfish Straitonia waterstoni from the Viséan of Lothian, Scotland
Authors: Sharp E. L. , Clack J. A.
Published: August 2012

The unique specimen of the Early Carboniferous lungfish Straitonia waterstoni is described in detail. As the only articulated lungfish currently described from the Viséan, it is of particular interest for lungfish evolution. It retains some plesiomorphic features of the skull, and shows some derived features in common with later Carboniferous forms. A thorough description is provided for future phylogenetic analyses. Straitonia has a number of diagnostic features. These include: a relatively narrow B-bone with a broad and curved anterior margin; an unpaired, parallel-sided C-bone whose margin is convex anteriorly; a B-bone approximately the same width as the single C-bone; the I-bones are relatively small compared with the B- and J-bones; the J-bones are tri-lobed; the XY bone is elongate along a posteromedial–anterolateral axis. Elongate fins dorsally and ventrally suggest a condition similar to those of later Carboniferous forms with confluent second dorsal, caudal and anal fins. It may thus be the earliest lungfish to show this condition. The ventral tail fin includes some fused elements, probably haemal and infrahaemal spines. The identity of one of the skull bones is discussed, and concluded to be a C-bone rather than a D-bone as previously described. The D-bone is absent, as in later Carboniferous forms. The history of the D-bone is considered.
Der Rollenschreib-Prozess als Theater-Therapieform
Authors: Otto Enrico
Published: August 2012

Zusammenfassung. Rollenschreiben ist in der Theaterdidaktik ein gängiger und pädagogisch wichtiger Aspekt, um einerseits Theaterstück-Rollen zu verstehen, in ihrer Struktur zu begreifen, um kreative Eigeninitiativen im Schreibprozess zu bewältigen und um sich andererseits mit entsprechenden dramaturgischen und theatralischen Mitteln auseinanderzusetzen. In der Theater-Therapie gelten ähnliche Voraussetzungen. Hierbei aber geht es eher um Schreib-Entwicklungs-Formen, die zu Korrekturen der gestörten Ich-Identität führen, wenn in einem Wechsel von Schreib- und Spielprozess diese Stück für Stück erkannt, die Veränderung beschrieben und in der Gruppen-Anspielsituation endgültig festgelegt und damit gefestigt wird.
Collage als therapeutisches Mittel in der Kunsttherapie mit Scheidungskindern
Authors: Ebersberger Sabine , Tomanek Justina
Published: August 2012

Zusammenfassung. Vorliegender Beitrag befasst sich mit den Therapiezielen und Interventionsmöglichkeiten bei Scheidungskindern. Es wird gezeigt, welche Funktionen die Kunsttherapie bei der Behandlung von Scheidungskindern einnehmen kann und es werden die methodischen Stärken der Arbeit mit Collage erläutert. Dabei steht eine allgemeine Diskussion der therapeutischen Möglichkeiten der Collagetechnik im Mittelpunkt, die über die reine Darstellung der Wirksamkeit und des Vorgehens im therapeutischen Einzelfall hinausgeht. Die gewählte Form dieses Beitrags führt Therapieziele, Vorgehen und Wirkung von Collageübungen zusammen und verdeutlicht wie in der Kunsttherapie mithilfe der Collage bestimmte Ziele erreicht werden können.
Sensitivity of the ocean's deep overturning circulation to easterly Antarctic winds
Authors: Stewart Andrew L. , Thompson Andrew F.
Published: August 2012

We investigate the sensitivity of the deep meridional overturning circulation (MOC) in the Southern Ocean to changes in the easterly wind stress over the Antarctic continental slope. The deep MOC is driven by export of dense Antarctic Bottom Water from the Antarctic continental shelf, and exerts a strong influence on climate by ventilating the deep ocean with oxygen and storing carbon dioxide. The possibility that inter‐climatic modifications of the deep overturning may have been driven by changes in the atmospheric circulation has motivated the recent interest in evaluating the sensitivity of the Southern Ocean MOC to modifications of the mid‐latitude westerlies. Using a high‐resolution eddy‐resolving model of a sector of the Southern Ocean, we show that the deep cell of the MOC is highly sensitive to the strength of the polar easterlies, and relatively insensitive to the strength of the mid‐latitude westerlies. Our results highlight that determining the deep ocean ventilation in past and future climates demands an accurate evaluation of the concurrent surface wind stress throughout the Southern Ocean.
Solar wind density controlling penetration electric field at the equatorial ionosphere during a saturation of cross polar cap potential
Authors: Wei Y. , Wan W. , Zhao B. , Hong M. , Ridley A. , Ren Z. , Fraenz M. , Dubinin E. , He M.
Published: August 2012

The most important source of electrodynamic disturbances in the equatorial ionosphere during the main phase of a storm is the prompt penetration electric field (PPEF) originating from the high‐latitude region. It has been known that such an electric field is correlated with the magnetospheric convection or interplanetary electric field. Here we show a unique case, in which the electric field disturbance in the equatorial ionosphere cannot be interpreted by this concept. During the superstorm on Nov. 20–21, 2003, the cross polar cap potential (CPCP) saturated at least for 8.2 h. The CPCP reconstructed by Assimilative Mapping of Ionospheric Electrodynamics (AMIE) procedure suggested that the PPEF at the equatorial ionosphere still correlated with the saturated CPCP, but the CPCP was controlled by the solar wind density instead of the interplanetary electric field. However, the predicted CPCPs by Hill‐Siscoe‐Ober (HSO) model and Boyle‐Ridley (BR) model were not fully consistent with the AMIE result and PPEF. The PPEF also decoupled from the convection electric field in the magnetotail. Due to the decoupling, the electric field in the ring current was not able to comply with the variations of PPEF, and this resulted in a long‐duration electric field penetration without shielding.
Impact of tropical cyclones on the ocean heat budget in the Bay of Bengal during 1999: 2. Processes and interpretations
Authors: Wang Jih‐Wang , Han Weiqing , Sriver Ryan L.
Published: August 2012

The impacts of two consecutive, strong tropical cyclones (TCs) from October–November in 1999 on the Bay of Bengal (BoB) heat budget are examined using the Hybrid Coordinate Ocean Model. The model uses atmospheric conditions from reanalysis, reconstructed TC winds, and satellite‐observed winds and precipitation. We conduct a series of diagnostic experiments to isolate the model's response to the individual TC‐associated forcings. During the TCs, the BoB ocean heat content (OHC) is reduced, primarily due to TC‐wind induced southward ocean heat transport (OHT) and a reduction in surface downward radiation due to increased cloudiness. BoB OHC is largely restored in the following months via enhanced surface heat fluxes, associated with cold wake restoration, and positive northward OHT. The TCs' downward heat pumping effect is estimated to be ∼1.74 × 1018 J near the end of February 2000, which is less than estimates using previously published methods based on surface observations. The relatively weak heat pumping results from freshwater input by intense monsoon rainfall and river discharge in the BoB, which stabilizes stratification, forms a barrier layer, and generates temperature inversions during seasonal surface cooling. As a result, early stage TC winds entrain the warm barrier layer water and enhance enthalpy loss in the southeastern Bay, while mature stage TC winds erode the barrier layer, decrease SST through upwelling and entrainment of deeper cold water and reduce enthalpy loss in the northwestern Bay. Our findings suggest TC winds may significantly alter the interseasonal BoB heat budget through OHT and surface heat fluxes.
Low temperature aqueous alteration of basalt: Mineral assemblages of Deccan basalts and implications for Mars
Authors: Greenberger R. N. , Mustard J. F. , Kumar P. S. , Dyar M. D. , Breves E. A. , Sklute E. C.
Published: August 2012

Al‐rich phyllosilicates (kaolinite, montmorillonite) have been found in layers overlying Fe/Mg‐smectites on Mars, and it has been suggested that this stratigraphy formed through in situ leaching at the surface, similar to terrestrial weathering profiles. We are investigating the remotely sensed signatures of this type of weathering using ten samples from a vertical section of altered Deccan basalts and four samples collected nearby as an analog for leaching resulting in Al‐rich phyllosilicate over Fe/Mg‐smectite stratigraphies. Samples were analyzed with reflectance spectroscopy from 0.28 to 25.0μm, inductively coupled plasma atomic emission spectrometry for 10 major element concentrations (Al, Ca, Fe, K, Mg, Mn, Na, P, Si, Ti), loss on ignition for volatiles, x‐ray diffraction (XRD) for mineralogies, and Mössbauer spectroscopy for Fe redox state. Spectra of basalt samples were dominated by Fe2+ crystal field transitions with weak alteration bands near 1.4 and/or 1.9 μm. Reststrahlen bands in mid‐infrared showed the convolution of plagioclase and pyroxene features typical of basalts. Saprolite samples were incompletely leached, and their spectra were dominated by complex Al‐ and Fe/Mg‐bearing smectite clays and retained no original mafic signatures. XRD and Mössbauer detected pyroxene and plagioclase not visible by reflectance spectroscopy in some saprolite samples. Zeolites were present throughout the saprolite. The laterite was the most leached horizon, and all analyses showed kaolinite and iron oxide assemblages. This kaolinite and hematite association would be expected if kaolinite on Mars formed through leaching under conditions similar to those on Earth and has implications for abundant freshwater on the Martian surface.
Eosinophilic Cholangitis and Wirsungitis as Cause of Simultaneous Bile Duct Obstruction and Pancreatitis
Authors: Kroemer A. , Sabet-Baktach M. , Doenecke A. , Ruemmele P. , Scherer M. , Schlitt H. , Breidert M.
Published: August 2012

Eosinophilic cholangitis is a rare clinical entity characterised by transmural eosinophilic infiltration of the biliary system. The aetiology of this disease is still unclear. We report on a 49-year-old male patient who presented with symptoms of obstructive jaundice and imaging suggestive for periampullary carcinoma. After partial pancreatoduodenectomy for suspected pancreatic cancer, pathology revealed massive eosinophilic cholecystitis as well as intra- and extrahepatic eosinophilic cholangitis with pseudopolypoid papillary lesions. Our case illustrates the diagnostic pitfalls in eosinophilic cholangitis as careful imaging procedures − optimally interdisciplinary − should be considered and performed in such patients. In conclusion, eosinophilic cholangitis is an uncommon, inflammatory condition that needs to be considered as a differential diagnosis for periampullary malignancies.
Acute Liver Failure Following Minocycline Treatment – A Case Report and Review of the Literature
Authors: Kuhn A. , Weiler-Normann C. , Schramm C. , Kluge S. , Behne M. , Lohse A. , Benten D.
Published: August 2012

We present the case of a 23-year-old female patient with acute liver failure following intake of minocycline. This patient had severe hypereosinophilia and massively increased IgE levels. Experimental studies in this case revealed elevated IFN-γ-, as well as TNF-α-producing CD4+ and CD8+ T-cells after in vitro stimulation with minocycline, indicating a type I/IgE-mediated as well as type II/cytotoxic reaction in the pathogenesis of minocycline-induced liver failure. Although mild forms of liver involvement are well known side effects of minocycline, only 8 cases with acute liver failure have been reported, and we present a review of all cases.
Diagnostisches Vorgehen bei Lebererkrankungen durch pflanzliche Mittel
Authors: Teschke R. , Schulze J. , Eickhoff A.
Published: August 2012

Hintergrund: Lebererkrankungen durch pflanzliche Mittel sind selten und werden ärztlicherseits und regulatorisch meist nicht sorgfältig genug evaluiert, mit der Konsequenz, dass wichtige alternative Erkrankungen mit spezifischen Therapiemöglichkeiten verpasst werden. Zudem lässt die Datenqualität oft Defizite erkennen und erschwert zusätzlich eine adäquate Evaluierung.

Methode: Basierend auf eigenen Erfahrungen und einer selektiven Literaturrecherche wurden Empfehlungen erarbeitet, die Datenerhebung und die Kausalitätsbewertung wesentlich zu verbessern.

Ergebnisse: Die für die Diagnose einer hepatischen UAW wichtigen Kriterien umfassen klinische Manifestation, Abklingphase, Typ der Leberschädigung, (ungewollte) Reexposition, Komedikation, Risikofaktoren, Einbeziehung der Grunderkrankung und sicherer Ausschluss alternativer Ursachen. Dabei kann die Datenqualität der Fälle von Lebererkrankungen durch primär vermutete pflanzliche Mittel allein durch ein striktes Vorgehen bei der Datenerhebung unter Verwendung eines leberspezifischen Meldeformulars wesentlich verbessert werden. Zur Kausalitätssicherung steht zudem eine leberspezifische Skala zur Verfügung, die sich sowohl bei den behandelnden Ärzten als auch den regulatorischen Bewertungen im Rahmen der notwendigen Pharmakovigilanz bewährt hat und weiter ausgebaut werden sollte. Durch verschiedene diagnostische Schritte ist darüber hinaus sicherzustellen, dass alternative Ursachen der Symptomatik rechtzeitig erkannt und diesbezügliche adäquate Therapien eingeleitet werden.

Schlussfolgerung: In der Klinik und Praxis stellen primär vermutete hepatische Nebenwirkungen von pflanzlichen Mitteln eine besondere ärztliche und regulatorische Herausforderung dar, die einer deutlich verbesserten Datenqualität und Kausalitätsevaluierung bedarf.
Zertifizierte Darmkrebszentren aus Sicht der Zentrumsleitungen: Ergebnisse einer Schlüsselpersonenbefragung
Authors: Huthmann D. , Seufferlein T. , Post S. , Benz S. , Stinner B. , Wesselmann S.
Published: August 2012

Seit 2003 zertifiziert die Deutsche Krebsgesellschaft (DKG) Organkrebszentren in Deutschland: Nach 8 Jahren Praxis gibt es mehr als 600 zertifizierte Krebszentren, die eine wie im Nationalen Krebsplan geforderte „qualitätsgesicherte onkologische Versorgung“ in Deutschland ermöglichen. Dabei behandeln die mehr als 200 zertifizierten Darmkrebszentren rund 25 % aller Darmkrebsneuerkrankungen. In diesem Artikel wird der Frage nachgegangen, welche Veränderungen das Zertifizierungskonzept in die Zentren gebracht hat.
Noncommutative Pfaffians and classification of states of five-dimensional quasi-spin
Authors: Artamonov Dmitry , Goloubeva Valentina
Published: August 2012

Noncommutative Pfaffians associated with an orthogonal algebra \documentclass[12pt]{minimal}\begin{document}$\mathfrak {o}_N$\end{document}oN are some special elements of the universal enveloping algebra \documentclass[12pt]{minimal}\begin{document}$U(\mathfrak {o}_N)$\end{document}U(oN). Using Pfaffians we construct the fourth quantum number which together with the naturally defined three quantum numbers allows to classify the states of a five-dimensional quasi-spin. The Pfaffians are treated as creation operators for the new quantum number.
Conformational dynamics of ATP/Mg:ATP in motor proteins via data mining and molecular simulation
Authors: Bojovschi A. , Liu Ming S. , Sadus Richard J.
Published: August 2012

The conformational diversity of ATP/Mg:ATP in motor proteins was investigated using molecular dynamics and data mining. Adenosine triphosphate (ATP) conformations were found to be constrained mostly by inter cavity motifs in the motor proteins. It is demonstrated that ATP favors extended conformations in the tight pockets of motor proteins such as F1-ATPase and actin whereas compact structures are favored in motor proteins such as RNA polymerase and DNA helicase. The incorporation of Mg2+ leads to increased flexibility of ATP molecules. The differences in the conformational dynamics of ATP/Mg:ATP in various motor proteins was quantified by the radius of gyration. The relationship between the simulation results and those obtained by data mining of motor proteins available in the protein data bank is analyzed. The data mining analysis of motor proteins supports the conformational diversity of the phosphate group of ATP obtained computationally.
Exponential renormalisation. II. Bogoliubov's R-operation and momentum subtraction schemes
Authors: Ebrahimi-Fard Kurusch , Patras Frédéric
Published: August 2012

This article aims at advancing the recently introduced exponential method for renormalisation in perturbative quantum field theory. It is shown that this new procedure provides a meaningful recursive scheme in the context of the algebraic and group theoretical approach to renormalisation. In particular, we describe in detail a Hopf algebraic formulation of Bogoliubov's classical R-operation and counterterm recursion in the context of momentum subtraction schemes. This approach allows us to propose an algebraic classification of different subtraction schemes. Our results shed light on the peculiar algebraic role played by the degrees of Taylor jet expansions, especially the notion of minimal subtraction and oversubtractions.
Density matrix treatment of non-adiabatic photoinduced electron transfer at a semiconductor surface
Authors: Micha David A.
Published: August 2012

Photoinduced electron transfer at a nanostructured surface leads to localized transitions and involves three different types of non-adiabatic couplings: vertical electronic transitions induced by light absorption emission, coupling of electronic states by the momentum of atomic motions, and their coupling due to interactions with electronic density fluctuations and vibrational motions in the substrate. These phenomena are described in a unified way by a reduced density matrix (RDM) satisfying an equation of motion that contains dissipative rates. The RDM treatment is used here to distinguish non-adiabatic phenomena that are localized from those due to interaction with a medium. The fast decay of localized state populations due to electronic density fluctuations in the medium has been treated within the Lindblad formulation of rates. The formulation is developed introducing vibronic states constructed from electron orbitals available from density functional calculations, and from vibrational states describing local atomic displacements. Related ab initio molecular dynamics calculations have provided diabatic momentum couplings between excited electronic states. This has been done in detail for an indirect photoexcitation mechanism of the surface Ag3Si(111):H, which leads to long lasting electronic charge separation. The resulting coupled density matrix equations are solved numerically to obtain the population of the final charge-separated state as it changes over time, for several values of the diabatic momentum coupling. New insight and unexpected results are presented here which can be understood in terms of photoinduced non-adiabatic transitions involving many vibronic states. It is found that the population of long lasting charge separation states is larger for smaller momentum coupling, and that their population grows faster for smaller coupling.
Symmetry, vibrational energy redistribution and vibronic coupling: The internal conversion processes of cycloketones
Authors: Kuhlman Thomas S. , Sauer Stephan P. A. , Sølling Theis I. , Møller Klaus B.
Published: August 2012

In this paper, we discern two basic mechanisms of internal conversion processes; one direct, where immediate activation of coupling modes leads to fast population transfer and one indirect, where internal vibrational energy redistribution leads to equidistribution of energy, i.e., ergodicity, and slower population transfer follows. Using model vibronic coupling Hamiltonians parameterized on the basis of coupled-cluster calculations, we investigate the nature of the Rydberg to valence excited-state internal conversion in two cycloketones, cyclobutanone and cyclopentanone. The two basic mechanisms can amply explain the significantly different time scales for this process in the two molecules, a difference which has also been reported in recent experimental findings [T. S. Kuhlman, T. I. Sølling, and K. B. Møller, ChemPhysChem. 13, 820 (2012)]10.1002/cphc.201100929.
Hydration structures of U(III) and U(IV) ions from ab initio molecular dynamics simulations
Authors: Leung Kevin , Nenoff Tina M.
Published: August 2012

We apply DFT+U-based ab initio molecular dynamics simulations to study the hydration structures of U(III) and U(IV) ions, pertinent to redox reactions associated with uranium salts in aqueous media. U(III) is predicted to be coordinated to 8 water molecules, while U(IV) has a hydration number between 7 and 8. At least one of the innershell water molecules of the hydrated U(IV) complex becomes spontaneously deprotonated. As a result, the U(IV)–O pair correlation function exhibits a satellite peak at 2.15 Å  associated with the shorter U(IV)–(OH−) bond. This feature is not accounted for in analysis of extended x-ray absorption fine structure and x-ray adsorption near edge structure measurements, which yield higher estimates of U(IV) hydration numbers. This suggests that it may be useful to include the effect of possible hydrolysis in future interpretation of experiments, especially when the experimental pH is close to the reported hydrolysis equilibrium constant value.
Self-consistent treatment of the local dielectric permittivity and electrostatic potential in solution for polarizable macromolecular force fields
Authors: Hassan Sergio A.
Published: August 2012

A self-consistent method is presented for the calculation of the local dielectric permittivity and electrostatic potential generated by a solute of arbitrary shape and charge distribution in a polar and polarizable liquid. The structure and dynamics behavior of the liquid at the solute/liquid interface determine the spatial variations of the density and the dielectric response. Emphasis here is on the treatment of the interface. The method is an extension of conventional methods used in continuum protein electrostatics, and can be used to estimate changes in the static dielectric response of the liquid as it adapts to charge redistribution within the solute. This is most relevant in the context of polarizable force fields, during electron structure optimization in quantum chemical calculations, or upon charge transfer. The method is computationally efficient and well suited for code parallelization, and can be used for on-the-fly calculations of the local permittivity in dynamics simulations of systems with large and heterogeneous charge distributions, such as proteins, nucleic acids, and polyelectrolytes. Numerical calculation of the system free energy is discussed for the general case of a liquid with field-dependent dielectric response.
Direct measurement of S-branch N2-H2 Raman linewidths using time-resolved pure rotational coherent anti-Stokes Raman spectroscopy
Authors: Bohlin A. , Nordström E. , Patterson B. D. , Bengtsson P.-E. , Kliewer C. J.
Published: August 2012

S-branch N2-H2 Raman linewidths have been measured in the temperature region 294–1466 K using time-resolved dual-broadband picosecond pure rotational coherent anti-Stokes Raman spectroscopy (RCARS). Data are extracted by mapping the dephasing rates of the CARS signal temporal decay. The J-dependent coherence decays are detected in the time domain by following the individual spectral lines as a function of probe delay. The linewidth data set was employed in spectral fits of N2 RCARS spectra recorded in binary mixtures of N2 and H2 at calibrated temperature conditions up to 661 K using a standard nanosecond RCARS setup. In this region, the set shows a deviation of less than 2% in comparison with thermocouples. The results provide useful knowledge for the applicability of N2 CARS thermometry on the fuel-side of H2 diffusion flames.
A combined spectroscopic and theoretical study of propofol·(H2O)3
Authors: León Iker , Cocinero Emilio J. , Millán Judith , Rijs Anouk M. , Usabiaga Imanol , Lesarri Alberto , Castaño Fernando , Fernández José A.
Published: August 2012

Propofol (2,6-di-isopropylphenol) is probably the most widely used general anesthetic. Previous studies focused on its complexes containing 1 and 2 water molecules. In this work, propofol clusters containing three water molecules were formed using supersonic expansions and probed by means of a number of mass-resolved laser spectroscopic techniques. The 2-color REMPI spectrum of propofol·(H2O)3 contains contributions from at least two conformational isomers, as demonstrated by UV/UV hole burning. Using the infrared IR/UV double resonance technique, the IR spectrum of each isomer was obtained both in ground and first excited electronic states and interpreted in the light of density functional theory (DFT) calculations at M06-2X/6-311++G(d,p) and B3LYP/6-311++G(d,p) levels. The spectral analysis reveals that in both isomers the water molecules are forming cyclic hydrogen bond networks around propofol's OH moiety. Furthermore, some evidences point to the existence of isomerization processes, due to a complicated conformational landscape and the existence of multiple paths with low energy barriers connecting the different conformers. Such processes are discussed with the aid of DFT calculations.
Confocal micro-x-ray fluorescence spectrometer for light element analysis
Authors: Smolek S. , Pemmer B. , Fölser M. , Streli C. , Wobrauschek P.
Published: August 2012

An existing micro-x-ray fluorescence (micro-XRF) spectrometer designed for light element analysis (6 ≤ Z ≤ 14) has been extended to confocal geometry: a second polycapillary x-ray optic has been introduced in front of the energy dispersive x-ray detector. New piezo positioners for optimum alignment of both optics have been installed inside the vacuum chamber. The spectrometer offers now the possibility of true 3D elemental analysis in the micrometer regime. Depth resolution varies between 100 μm at 1 keV fluorescence energy (Na-Kα) and 30 μm for 17.5 keV (Mo). To further extend analytical capabilities a second x-ray tube with a Rh anode has been acquired to supplement to existing Mo anode tube. Lower limits of detection have been determined to be in the ppm region for confocal geometry. The spectrometer has been characterized and tested using different samples. Furthermore, results have been compared with SR micro-XRF to show the capabilities and limitations of this spectrometer.
Solution of the Dirac equation with pseudospin symmetry for a new harmonic oscillatory ring-shaped noncentral potential
Authors: Zhang Min-Cang , Liu Zhi-Cun
Published: August 2012

A new harmonic oscillatory ring-shaped noncentral potential is proposed in which the noncentral electric dipole and a novel angle-dependent component are included. The pseudospin symmetry for this potential is investigated by working in a complete square integrable basis that supports a tridiagonal matrix representation of the wave operator. The resulting three-term recursion relation for the expansion coefficients of the wavefunctions (both angular and radial) is presented. The angular/radial wavefunction is written in terms of the Jacobi/Laguerre polynomials. The discrete spectrum of the bound states is obtained by diagonalization of the radial recursion relation.
Photon recycling across a ultraviolet-blocking layer by luminescence in polymer solar cells
Authors: Engmann Sebastian , Machalett Marie , Turkovic Vida , Rösch Roland , Rädlein Edda , Gobsch Gerhard , Hoppe Harald
Published: August 2012

UV-blocking layers can increase the long term stability of organic solar cell devices; however, they limit the amount of light that can be utilized for energy conversion. We present photon recycling and down-conversion via a luminescent layer across a UV-blocking TiO2 layer. Our results show that the use of an additional UV-blocking layer does not necessarily reduce the overall efficiency of organic solar cells, since the loss in photocurrent due to the UV-absorption loss can be partially compensated using high energy photon down-conversion via luminescence layers.
A transient electron transport analysis of bulk wurtzite zinc oxide
Authors: Hadi Walid A. , Shur Michael S. , O’Leary Stephen K.
Published: August 2012

A three-valley Monte Carlo simulation approach is used in order to probe the transient electron transport that occurs within bulk wurtzite zinc oxide. For the purposes of this analysis, we follow O’Leary et al. [Solid State Commun. 150, 2182 (2010)], and study how electrons, initially in thermal equilibrium, respond to the sudden application of a constant applied electric field. We find that for applied electric field strength selections in excess of 300 kV/cm that an overshoot in the electron drift velocity is observed. An undershoot in the electron drift velocity is also observed for applied electric field strength selections in excess of 700 kV/cm, this velocity undershoot not being observed for other compound semiconductors, such as gallium arsenide and gallium nitride. We employ a means of rendering transparent the electron drift velocity enhancement offered by the transient electron transport, and then use the calculated dependence of the peak transient electron drift velocity on the applied electric field for the design optimization of short-channel high-frequency electron devices.
Nonvolatile memory thin film transistors using CdSe/ZnS quantum dot-poly(methyl methacrylate) composite layer formed by a two-step spin coating technique
Authors: Chen Ying-Chih , Huang Chun-Yuan , Yu Hsin-Chieh , Su Yan-Kuin
Published: August 2012

The nonvolatile memory thin film transistors (TFTs) using a core/shell CdSe/ZnS quantum dot (QD)-poly(methyl methacrylate) (PMMA) composite layer as the floating gate have been demonstrated, with the device configuration of n+-Si gate/SiO2 insulator/QD-PMMA composite layer/pentacene channel/Au source-drain being proposed. To achieve the QD-PMMA composite layer, a two-step spin coating technique was used to successively deposit QD-PMMA composite and PMMA on the insulator. After the processes, the variation of crystal quality and surface morphology of the subsequent pentacene films characterized by x-ray diffraction spectra and atomic force microscopy was correlated to the two-step spin coating. The crystalline size of pentacene was improved from 147.9 to 165.2 Å, while the degree of structural disorder was decreased from 4.5% to 3.1% after the adoption of this technique. In pentacene-based TFTs, the improvement of the performance was also significant, besides the appearances of strong memory characteristics. The memory behaviors were attributed to the charge storage/discharge effect in QD-PMMA composite layer. Under the programming and erasing operations, programmable memory devices with the memory window (Δ Vth) = 23 V and long retention time were obtained.
A generalized any particle propagator theory: Assessment of nuclear quantum effects on electron propagator calculations
Authors: Romero Jonathan , Posada Edwin , Flores-Moreno Roberto , Reyes Andrés
Published: August 2012

In this work we propose an extended propagator theory for electrons and other types of quantum particles. This new approach has been implemented in the LOWDIN package and applied to sample calculations of atomic and small molecular systems to determine its accuracy and performance. As a first application of the method we have studied the nuclear quantum effects on electron ionization energies. We have observed that ionization energies of atoms are similar to those obtained with the electron propagator approach. However, for molecular systems containing hydrogen atoms there are improvements in the quality of the results with the inclusion of nuclear quantum effects. An energy term analysis has allowed us to conclude that nuclear quantum effects are important for zero order energies whereas propagator results correct the electron and electron-nuclear correlation terms. Results presented for a series of n-alkanes have revealed the potential of this method for the accurate calculation of ionization energies of a wide variety of molecular systems containing hydrogen nuclei. The proposed methodology will also be applicable to exotic molecular systems containing positrons or muons.
Conical intersection seams in polyenes derived from their chemical composition
Authors: Nenov Artur , de Vivie-Riedle Regina
Published: August 2012

The knowledge of conical intersection seams is important to predict and explain the outcome of ultrafast reactions in photochemistry and photobiology. They define the energetic low-lying reachable regions that allow for the ultrafast non-radiative transitions. In complex molecules it is not straightforward to locate them. We present a systematic approach to predict conical intersection seams in multifunctionalized polyenes and their sensitivity to substituent effects. Included are seams that facilitate the photoreaction of interest as well as seams that open competing loss channels. The method is based on the extended two-electron two-orbital method [A. Nenov and R. de Vivie-Riedle, J. Chem. Phys. 135, 034304 (2011)]10.1063/1.3608924. It allows to extract the low-lying regions for non-radiative transitions, which are then divided into small linear segments. Rules of thumb are introduced to find the support points for these segments, which are then used in a linear interpolation scheme for a first estimation of the intersection seams. Quantum chemical optimization of the linear interpolated structures yields the final energetic position. We demonstrate our method for the example of the electrocyclic isomerization of trifluoromethyl-pyrrolylfulgide.
Room-temperature structures of solid hydrogen at high pressures
Authors: Liu Hanyu , Zhu Li , Cui Wenwen , Ma Yanming
Published: August 2012

By employing first-principles metadynamics simulations, we explore the 300 K structures of solid hydrogen over the pressure range 150–300 GPa. At 200 GPa, we find the ambient-pressure disordered hexagonal close-packed (hcp) phase transited into an insulating partially ordered hcp phase (po-hcp), a mixture of ordered graphene-like H2 layers and the other layers of weakly coupled, disordered H2 molecules. Within this phase, hydrogen remains in paired states with creation of shorter intra-molecular bonds, which are responsible for the very high experimental Raman peak above 4000 cm−1. At 275 GPa, our simulations predicted a transformation from po-hcp into the ordered molecular metallic Cmca phase (4 molecules/cell) that was previously proposed to be stable only above 400 GPa. Gibbs free energy calculations at 300 K confirmed the energetic stabilities of the po-hcp and metallic Cmca phases over all known structures at 220–242 GPa and >242 GPa, respectively. Our simulations highlighted the major role played by temperature in tuning the phase stabilities and provided theoretical support for claimed metallization of solid hydrogen below 300 GPa at 300 K.
About non-maximality of the action functional
Authors: Freire W. , Lima J. P. N.
Published: August 2012

In this work first we review some cases where the action exhibits a minimal or a saddle-point criticality for velocity-independent potentials (V(x, t)) and maximum when the potential is velocity-dependent (\documentclass[12pt]{minimal}\begin{document}$V(x,\dot{x},t)$\end{document}V(x,ẋ,t)). In the following we will use the functional (“directional”) derivative of second order to present a mathematically rigorous proof of the non-maximality of the classical functional action for potentials V(x, t) velocity-independent.
Histological and molecular investigation of the basis for variation in tomato fruit size in response to fruit load and genotype
Authors: Fanwoua Julienne , de Visser Pieter H. B. , Heuvelink Ep , Angenent Gerco , Yin Xinyou , Marcelis Leo F. M. , Struik Paul C.
Published: August 2012

Understanding the molecular mechanisms and cellular dynamics that cause variation in fruit size is critical for the control of fruit growth. The aim of this study was to investigate how both genotypic factors and carbohydrate limitation cause variation in fruit size. We grew a parental line (Solanum lycopersicum L.) and two inbred lines from Solanum chmielewskii (C.M.Rick et al.; D.M.Spooner et al.) producing small or large fruits under three fruit loads (FL): continuously two fruits/truss (2&2F) or five fruits/truss (5&5F) and a switch from five to two fruits/truss (5&2F) 7 days after anthesis (DAA). Final fruit size, sugar content and cell phenotypes were measured. The expression of major cell cycle genes 7 DAA was investigated using quantitative PCR. The 5&5F treatment resulted in significantly smaller fruits than the 5&2F and 2&2F treatments. In the 5&5F treatment, cell number and cell volume contributed equally to the genotypic variation in final fruit size. In the 5&2F and 2&2F treatment, cell number contributed twice as much to the genotypic variation in final fruit size than cell volume did. FL treatments resulted in only subtle variations in gene expression. Genotypic differences were detected in transcript levels of CycD3 (cyclin) and CDKB1 (cyclin-dependent-kinase), but not CycB2. Genotypic variation in fruit FW, pericarp volume and cell volume was linked to pericarp glucose and fructose content (R2 = 0.41, R2 = 0.48, R2 = 0.11 respectively). Genotypic variation in cell number was positively correlated with pericarp fructose content (R2 = 0.28). These results emphasise the role of sugar content and of the timing of assimilate supply in the variation of cell and fruit phenotypes.
An investigation of runoff from raised beds and other tillage methods in the high rainfall zone of south-western Victoria, Australia
Authors: Holland J. E. , Johnston T. H. , White R. E. , Orchard B. A.
Published: August 2012

For many years, the poor physical and hydraulic properties of the soils in south-western Victoria have restricted crop production due to waterlogging. In this region of predominantly winter rainfall, raised beds have become popular with farmers to overcome these difficulties; however, little has been reported on the hydrology of raised beds compared with other tillage systems for cropping in the rain-fed environment of south-western Victoria. This study measured rainfall characteristics, runoff volumes, and soil properties such as the soil water content, bulk density, and hydraulic conductivity for three tillage treatments (raised beds, conventional cultivation, and deep cultivation) over 6 years on a Sodosol at a field site near Geelong, Victoria. Runoff was regressed against rainfall variables such as the amount per event, hours of rainfall, rainfall intensity, and maximum rainfall intensity to determine the significance of any differences between the treatments. The relationship between runoff and rainfall amount was best described with an exponential model. Raised beds significantly increased the amount of runoff relative to the other treatments when above-average rainfall was received, but there was little difference in runoff in years of below-average rainfall. No consistent effect of runoff on crop biomass was detected nor could any differences in runoff be attributed to differences in soil water content, hydraulic conductivity, and bulk density between treatments. The most important factor appeared to be the furrows between the raised beds, which acted as conduits for the flow of surface water during the larger storm events. During such events, runoff is an important hydrological process in cropping land in south-western Victoria.
Nearly Euclidean Thurston maps
Authors: Cannon J. , Floyd W. , Parry W. , Pilgrim K.
Published: August 2012

We take an in-depth look at Thurston’s combinatorial characterization of rational functions for a particular class of maps we call nearly Euclidean Thurston maps. These are orientation-preserving branched maps

f
:

S
2

→

S
2

f\colon S^2\to S^2

whose local degree at every critical point is

2
2

and which have exactly four postcritical points. These maps are simple enough to be tractable, but are complicated enough to have interesting dynamics.
Visualizing and QuantifyingFusarium oxysporumin the Plant Host
Authors: Diener Andrew
Published: August 2012

Host-specific forms of Fusarium oxysporum infect the roots of numerous plant species. I present a novel application of familiar methodology to visualize and quantify F. oxysporum in roots. Infection in the roots of Arabidopsis thaliana, tomato, and cotton was detected with colorimetric reagents that are substrates for Fusarium spp.-derived arabinofuranosidase and N-acetyl-glucosaminidase activities and without the need for genetic modification of either plant host or fungal pathogen. Similar patterns of blue precipitation were produced by treatment with 5-bromo-4-chloro-3-indoxyl-α-l-arabinofuranoside and 5-bromo-4-chloro-3-indoxyl-2-acetamido-2-deoxy-β-d-glucopyranoside, and these patterns were consistent with prior histological descriptions of F. oxysporum in roots. Infection was quantified in roots of wild-type and mutant Arabidopsis using 4-nitrophenyl-α-l-arabinofuranoside. In keeping with an expectation that disease severity above ground is correlated with F. oxysporum infection below ground, elevated levels of arabinofuranosidase activity were measured in the roots of susceptible agb1 and rfo1 while a reduced level was detected in the resistant eir1. In contrast, disease severity and F. oxysporum infection were uncoupled in tir3. The distribution of staining patterns in roots suggests that AGB1 and RFO1 restrict colonization of the vascular cylinder by F. oxysporum whereas EIR1 promotes colonization of root apices.