bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient and automatic calculation of optical band shapes and resonance Raman spectra for larger molecules within the independent mode displaced harmonic oscillator model
Authors: Petrenko Taras , Neese Frank
Published: December 2012

In this work, an improved method for the efficient automatic simulation of optical band shapes and resonance Raman (rR) intensities within the “independent mode displaced harmonic oscillator” is described. Despite the relative simplicity of this model, it is able to account for the intensity distribution in absorption (ABS), fluorescence, and rR spectra corresponding to strongly dipole allowed electronic transitions with high accuracy. In order to include temperature-induced effects, we propose a simple extension of the time dependent wavepacket formalism developed by Heller which enables one to derive analytical expressions for the intensities of hot bands in ABS and rR spectra from the dependence of the wavepacket evolution on its initial coordinate. We have also greatly optimized the computational procedures for numerical integration of complicated oscillating integrals. This is important for efficient simulations of higher-order rR spectra and excitation profiles, as well as for the fitting of experimental spectra of large molecules. In particular, the multimode damping mechanism is taken into account for efficient reduction of the upper time limit in the numerical integration. Excited state energy gradient as well as excited state geometry optimization calculations are employed in order to determine excited state dimensionless normal coordinate displacements. The gradient techniques are highly cost-effective provided that analytical excited state derivatives with respect to nuclear displacements are available. Through comparison with experimental spectra of some representative molecules, we illustrate that the gradient techniques can even outperform the geometry optimization method if the harmonic approximation becomes inadequate.
Controllable evaporation of cesium from a dispenser oven
Authors: Fantz U. , Friedl R. , Fröschle M.
Published: December 2012

This instrument allows controlled evaporation of the alkali metal cesium over a wide range of evaporation rates. The oven has three unique features. The first is an alkali metal reservoir that uses a dispenser as a cesium source. The heating current of the dispenser controls the evaporation rate allowing generation of an adjustable and stable flow of pure cesium. The second is a blocking valve, which is fully metallic as is the body of the oven. This construction both reduces contamination of the dispenser and enables the oven to be operated up to 300 °C, with only small temperature variations (<5 °C). By minimizing the temperature variation, the built up of the alkali metal at a cold spot is significantly hindered. The last feature is an integral surface ionization detector for measuring and controlling the evaporation rate. The dispenser oven can be easily transferred to the other alkali-metals.
Thermoelectric magnetic force acting on the solid during directional solidification under a static magnetic field
Authors: Wang J. , Fautrelle Y. , Ren Z. M. , Li X. , Nguyen-Thi H. , Mangelinck-Noel N. , Salloum Abou Jaoude G. , Zhong Y. B. , Kaldre I. , Bojarevics A. , Buligins L.
Published: December 2012

Thermoelectric magnetic force (TEMF), which is induced by the interaction between the thermoelectric current and the applied magnetic field, acting on the solid during directional solidification under a static magnetic field was derived. Equipping the derived equation, an analytical calculation of the velocity of a solid spherical particle submitted to the TEMF was carried out. The experiment with corresponding phenomenon was performed and recorded by the in situ synchrotron X-ray imaging, which permitted a direct measurement of the velocity of the TEMF-driven motion of detached fragments. The measurement of the velocities showed a reasonable agreement with the calculation results.
Double-templated electrodeposition: Simple fabrication of micro-nano hybrid structure by electrodeposition for efficient boiling heat transfer
Authors: Shin Sangwoo , Seok Kim Beom , Choi Geehong , Lee Hwanseong , Hee Cho Hyung
Published: December 2012

Micro-nano hybrid structure (MNHS) that comprises of microcavities and nanowires is a specific class of MNHS that is considered to be ideal for two-phase boiling heat transfer applications. Realizing MNHS with electrodeposition is favorable in boiling heat transfer, but the realization has been very difficult and time-consuming to achieve. Here, we demonstrate a simple, robust, rapid, and photolithography-free route to fabricate MNHS that consists of individual microcavities and copper nanowires on a large area. We show that this MNHS can be extremely beneficial in boiling heat transfer compared to the state-of-the-art nanowire surface.
Multi-finger flexible graphene field effect transistors with high bendability
Authors: Lee Jongho , Tao Li , Parrish Kristen N. , Hao Yufeng , Ruoff Rodney S. , Akinwande Deji
Published: December 2012

Highly bendable graphene field-effect transistors are fabricated on polyimide films. The device offers robust performance against various conditions including immersion in liquids, and dynamic loading tests, which are hazardous to conventional electronics. Bendability of the sample is tested with the bending radius of down to 1.3 mm; the devices remain fully functional with less than 8.7% reduction and no reduction in the electron and hole mobility after repeated bending tests, respectively. Multi-finger electrodes are implemented on flexible substrates to enhance its current drive. Silicon-nitride passivation offers efficient chemical protection over diverse liquids and robust mechanical protection against impacts.
Probing ballistic microdrop coalescence by stroboscopic small-angle X-ray scattering
Authors: Graceffa R. , Burghammer M. , Davies R. J. , Riekel C.
Published: December 2012

The coalescence of ballistic microdrops has been explored by stroboscopic synchrotron radiation microbeam small-angle X-ray scattering (μSAXS). About 80 μm diameter microdrops generated by a drop-on-demand inkjet system travelled at ∼1.7 m/s through a ∼1 μm X-ray beam. Microdrops of cytochrome C and acetate buffer solutions were merged in order to study the pH driven conformational change. μSAXS patterns were accumulated on a pixel detector, which was activated for a few μsec during the transit time of each microdrop through the microbeam. Local probing of the merging microdrops reveals the internal protein solution flow.
Ion-induced grain growth and texturing in refractory thin films—A low temperature process
Authors: Seita M. , Reiser A. , Spolenak R.
Published: December 2012

Selective grain growth can be promoted in thin films independently of the materials intrinsic properties, such as the melting temperature, by ion-irradiation. This enables the previously impossible evolution of large grain-sized microstructures with controlled crystallographic textures even in refractory metals, such as α-tantalum. Experimental results from materials with different crystal structure are compared on the basis of a theoretical model, which reveals the differences in ion-induced grain-growth dynamics.
Oxidation states study of nickel in solid oxide fuel cell anode using x-ray full-field spectroscopic nano-tomography
Authors: Karen Chen-Wiegart Yu-chen , Harris William M. , Lombardo Jeffrey J. , Chiu Wilson K. S. , Wang Jun
Published: December 2012

Identifying the chemical state and coupling with morphological information in three dimensions are of great interest in energy storage materials, which typically involve reduction-oxidation cycling and structural evolution. Here, we apply x-ray nano-tomography with multiple x-ray energies to study oxidation states of nickel (Ni) and nickel oxide phases in Ni-yttria-stabilized zirconia (YSZ), a typical anode material of solid oxide fuel cells (SOFC). We present a method to quantitatively identify the nickel-based oxides from Ni-YSZ anode composite, and obtain chemical mapping as well as associated microstructures at nanometer scale in three dimensions. NiO particles manually placed on a Ni-YSZ composite anode were used for validation of the method, while no nickel oxides were found to be present within the electrode structure as remnants of the cell fabrication process. The application of the method can be widely applied to energy storage materials including SOFCs, Li-ion batteries, and supercapacitors, as well as other systems for oxidation and reduction study.
Experimental demonstration of a four-port photonic crystal cross-waveguide structure
Authors: Yu Yi , Heuck Mikkel , Ek Sara , Kuznetsova Nadezda , Yvind Kresten , Mørk Jesper
Published: December 2012

We report the design and fabrication of a four-port InP photonic crystal cavity-waveguide structure in which two crossing waveguides intersect in a cavity. Transmission measurements show that by exploiting mode-gap effects, high cross-talk suppression between the two waveguides can be obtained. In addition, the waveguides couple to two distinct cavity resonances with different quality-factors as well as small mode volumes. This structure is promising for realizing ultra-fast, low-energy optical switches or memories.
Propagation of femtosecond terawatt laser pulses in N2 gas including higher-order Kerr effects
Authors: Huang T. W. , Zhou C. T. , He X. T.
Published: December 2012

Propagation characteristic of femtosecond terawatt laser pulses in N2 gas with higher-order Kerr effect (HOKE) is investigated. Theoretical analysis shows that HOKE acting as Hamiltonian perturbation can destroy the coherent structure of a laser field and result in the appearance of incoherent patterns. Numerical simulations show that in this case two different types of complex structures can appear. It is found that the high-order focusing terms in HOKE can cause continuous phase shift and off-axis evolution of the laser fields when irregular homoclinic orbit crossings of the field in phase space take place. As the laser propagates, small-scale spatial structures rapidly appear and the evolution of the laser field becomes chaotic. The two complex patterns can switch between each other quasi-periodically. Numerical results show that the two complex patterns are associated with the stochastic evolution of the energy contained in the higher-order shorter-wavelength Fourier modes. Such complex patterns, associated with small-scale filaments, may be typical for laser propagation in a HOKE medium.
Recruiting and retaining general practitioners to a primary care asthma-intervention study in Australia
Authors: Shah Smita , Roydhouse Jessica K. , Toelle Brett G. , Mellis Craig M. , Jenkins Christine R. , Edwards Peter , Sawyer Susan M.
Published: December 2012

The need for more evidence-based interventions in primary care is clear. However, it is challenging to recruit general practitioners (GPs) for interventional research. This paper reports on the evaluation of three methods of recruitment that were sequentially used to recruit GPs for a randomised controlled trial of an asthma communication and education intervention in Australia. The recruitment methods (RMs) were: general practices were contacted by project staff from a Department of General Practice, University of Sydney (RM1); general practices were contacted by staff from an independent research organisation (RM2); and general practices were contacted by a medical peer (chief investigator) (RM3). A GP was defined as ‘recruited’ once they consented and were randomised to a group, and ‘retained’ if they provided baseline data and did not notify staff of their intention to withdraw at any time during the 12-month study. RM1 was used for the first 6 months, during which 34 (4%) GPs were recruited and 21 (62%) retained from a total of 953 invitations. RM2 was then used for the next 5 months, during which 32 (6%) GPs were recruited and 26 (81%) were retained. Finally over the next 7 months, RM3 recruited 84 (12%) GPs and retained 75 (89%) GPs. In conclusion, use of a medical peer as the first contact was associated with the highest recruitment and retention rate.
Regulation of SIK1 abundance and stability is critical for myogenesis
Authors: Stewart Randi , Akhmedov Dmitry , Robb Christopher , Leiter Courtney , Berdeaux Rebecca
Published: December 2012

cAMP signaling can both promote and inhibit myogenic differentiation, but little is known about the mechanisms mediating promyogenic effects of cAMP. We previously demonstrated that the cAMP response element-binding protein (CREB) transcriptional target salt-inducible kinase 1 (SIK1) promotes MEF2 activity in myocytes via phosphorylation of class II histone deacetylase proteins (HDACs). However, it was unknown whether SIK1 couples cAMP signaling to the HDAC-MEF2 pathway during myogenesis and how this response could specifically occur in differentiating muscle cells. To address these questions, we explored SIK1 regulation and function in muscle precursor cells before and during myogenic differentiation. We found that in primary myogenic progenitor cells exposed to cAMP-inducing agents,
Sik1
transcription is induced, but the protein is rapidly degraded by the proteasome. By contrast, sustained cAMP signaling extends the half-life of SIK1 in part by phosphorylation of Thr475, a previously uncharacterized site that we show can be phosphorylated by PKA in cell-free assays. We also identified a functional PEST domain near Thr475 that contributes to SIK1 degradation. During differentiation of primary myogenic progenitor cells, when PKA activity has been shown to increase, we observe elevated
Sik1
transcripts as well as marked accumulation and stabilization of SIK1 protein. Depletion of
Sik1
in primary muscle precursor cells profoundly impairs MEF2 protein accumulation and myogenic differentiation. Our findings support an emerging model in which SIK1 integrates cAMP signaling with the myogenic program to support appropriate timing of differentiation.
Mutation in
CSA
creates a new photoperiod-sensitive genic male sterile line applicable for hybrid rice seed production
Authors: Zhang Hui , Xu Chenxi , He Yi , Zong Jie , Yang Xijia , Si Huamin , Sun Zongxiu , Hu Jianping , Liang Wanqi , Zhang Dabing
Published: December 2012

Rice is a major staple food worldwide. Making hybrid rice has proved to be an effective strategy to significantly increase grain yield. Current hybrid rice technologies rely on male sterile lines and have been used predominantly in
indica
cultivars. However, intrinsic problems exist in the implementation of these technologies, such as limited germplasms and unpredictable conversions from sterility to fertility in the field. Here, we describe a photoperiod-controlled male sterile line,
carbon starved anther
(
csa
), which contains a mutation in an R2R3 MYB transcription regulator of pollen development. This mutation was introduced into
indica
and
japonica
rice, and it rendered male sterility under short-day conditions and male fertility under long-day conditions in both lines. Furthermore, F
1
plants of
csa
and a restorer line JP69 exhibited heterosis (hybrid vigor), suggesting the feasibility of using this mutation to create hybrid rice. The
csa
-based photoperiod-sensitive male sterile line allows the establishment of a stable two-line hybrid system, which promises to have a significant impact on agriculture.
ALMA and VLA observations of the outflows in IRAS 16293−2422
Authors: Loinard Laurent , Zapata Luis A. , Rodríguez Luis F. , Pech Gerardo , Chandler Claire J. , Brogan Crystal L. , Wilner David J. , Ho Paul T. P. , Parise Bérengère , Hartmann Lee W. , Zhu Zhaohuan , Takahashi Satoko , Trejo Alfonso
Published: December 2012

We present Atacama Large Millimeter/submillimeter Array (ALMA) and Very Large Array (VLA) observations of the molecular and ionized gas at 0.1–0.3 arcsec resolution in the Class 0 protostellar system IRAS 16293−2422. These data clarify the origins of the protostellar outflows from the deeply embedded sources in this complex region. Source A2 is confirmed to be at the origin of the well-known large-scale north-east–south-west flow. The most recent VLA observations reveal a new ejection from that protostar, demonstrating that it drives an episodic jet. The central compact part of the other known large-scale flow in the system, oriented roughly east–west, is well delineated by the CO(6-5) emission imaged with ALMA and is confirmed to be driven from within component A. Finally, a one-sided blueshifted bubble-like outflow structure is detected here for the first time from source B to the north-west of the system. Its very short dynamical time-scale (∼200 yr), low velocity and moderate collimation support the idea that source B is the youngest object in the system, and possibly one of the youngest protostars known.
Pathogenicity of Diatrypaceous Fungi on Grapevines in Australia
Authors: Pitt Wayne M. , Trouillas Florent P. , Gubler Walter D. , Savocchia Sandra , Sosnowski Mark R.
Published: December 2012

In addition to Eutypa lata, which causes Eutypa dieback, numerous other fungi in the Diatrypaceae family have been isolated from diseased grapevines (Vitis vinifera) and other woody hosts. Pathogenicity trials comprising 70 strains of diatrypaceous fungi representing nine species in six genera were conducted to determine whether these fungi, collected in Australia, were pathogenic to grapevines. When inoculated into wounded trunks of ‘Cabernet Sauvignon’, eight species, including E. lata, E. leptoplaca, Cryptovalsa ampelina, C. rabenhorstii, Eutypella citricola, E. microtheca, Diatrypella vulgaris, and a Diatrype sp. produced necrotic lesions significantly longer than on controls. In addition, all nine species (including a Cryptosphaeria sp.) were reisolated from the margins of developing lesions and at varying distances above and below the point of inoculation. Diatrypaceous fungi were frequently isolated from asymptomatic or otherwise healthy tissue several centimeters ahead of the disease margin. Methods to control diseases associated with diatrypaceous fungi must take into account their propensity to colonize woody tissues ahead of or in the absence of visible symptoms. Current recommendations for the management of Eutypa dieback using remedial surgery and pruning wound protection appear sufficient for the control of the other diatrypaceous fungi included in this study.
Embodied Energy Use in China’s Infrastructure Investment from 1992 to 2007: Calculation and Policy Implications
Authors: Liu Hongtao , Xi Youmin , Ren Bingqun , Zhou Heng
Published: December 2012

Infrastructure has become an important topic in a variety of areas of the policy debate, including energy saving and climate change. In this paper, we use an energy input-output model to evaluate the amounts of China’s embodied energy use in infrastructure investment from 1992 to 2007. We also use the structure decomposition model to analyze the factors impacting the embodied energy use in infrastructure investment for the same time period. The results show that embodied energy use in infrastructure investment accounted for a significant proportion of China’s total energy use with an increasing trend and reflect that improper infrastructure investment represents inefficient use of energy and other resources. Some quantitative information is provided for further determining the low carbon development potentials of China’s economy.
Optimization of Journal Bearing Profile for Higher Dynamic Stability Limits
Authors: Nicoletti Rodrigo
Published: December 2012

This work presents an optimization procedure to find bearing profiles that improve stability margins of rotor-bearing systems. The profile is defined by control points and cubic splines. Stability margins are estimated using bearing dynamic coefficients, and obtained solutions are analyzed as a function of the number of control points and of the Sommerfeld number at optimization. Results show the feasibility of finding shapes for the bearing that significantly improve the stability margins. Some of the obtained solutions overcome the stability margins of conventional bearings, such as the journal bearing and preloaded bearings with 0.5 and 0.67 preload. A time domain simulation of a flexible shaft rotating system supported by such bearings corroborates the results.
The Si3N4/TiN Interface: 1. TiN(001) Grown and Analyzed In situ using Angle-resolved X-ray Photoelectron Spectroscopy
Authors: Haasch Richard T. , Patscheider Jörg , Hellgren Niklas , Petrov Ivan , Greene J. E.
Published: December 2012

Angle-resolved x-ray photoelectron spectroscopy (AR-XPS) was used to analyze as-deposited epitaxial TiN(001) layers grown in situ. The films were grown by ultrahigh vacuum reactive magnetron sputtering onto MgO(001) at 600 °C in mixed 1:1 Ar/N2 discharges maintained at a total pressure of 0.5 Pa (3.75 × 10−3 Torr). AR-XPS spectra were obtained using incident monochromatic Al Kα radiation at 0.83401 nm. The results show that the TiN(001) surfaces are free of O and C. The Ti 2p photoelectron spectra of clean TiN are characterized by 2p3/2 and 2p1/2 lines appearing at 454.7 and 460.7 eV, each with corresponding satellite lines which are shifted ∼2.6 eV to higher binding energies.
The Si3N4/TiN Interface: 6. Si/TiN(001) Grown and Analyzed In situ using Angle-resolved X-ray Photoelectron Spectroscopy
Authors: Haasch Richard T. , Patscheider Jörg , Hellgren Niklas , Petrov Ivan , Greene J. E.
Published: December 2012

Angle-resolved x-ray photoelectron spectroscopy (AR-XPS) was used to analyze Si/TiN(001) bilayers grown by ultrahigh vacuum reactive magnetron sputter deposition on MgO(001), with an electrically floating substrate potential of 7 V, in mixed 1:1 Ar/N2 discharges maintained at a total pressure of 0.5 Pa (3.75 × 10−3 Torr). The TiN(001) films were grown at 600 °C and the 4-ML-thick Si overlayers at room temperature. AR-XPS spectra were obtained using incident monochromatic Al Kα x-radiation at 0.83401 nm. Si/TiN(001) Ti 2p spectra reveal reduced unscreened final-state satellite peaks compared to Ti 2p spectra obtained from uncapped TiN(001) due to increased electronic screening.
A low voltage “railgun”
Authors: Starr Stanley O. , Youngquist Robert C. , Cox Robert B.
Published: December 2012

Due to recent advances in solid-state switches and ultra-capacitors, it is now possible to construct a “railgun” that can operate at voltages below 20 V. Railguns typically operate above a thousand volts, generating huge currents for a few milliseconds to provide thousands of g's of acceleration to a small projectile. The low voltage railgun described herein operates for much longer time periods (tenths of seconds to seconds), has far smaller acceleration and speed, but can potentially propel a much larger object. The impetus for this development is to lay the groundwork for a possible ground-based supersonic launch track, but the resulting system may also have applications as a simple linear motor. The system would also be a useful teaching tool, requiring concepts from electrodynamics, mechanics, and electronics for its understanding, and is relatively straightforward to construct.
Resource Letter PoD-1: The Physics of Dance
Authors: Laws Kenneth , Lott Melanie
Published: December 2012

This Resource Letter provides a guide to the literature on the physics of dance. Journal articles and books are cited for the following topics: General references for dance, physics of dance, research methods in physics of human movement and in biomechanics, using dance in the physics classroom; anatomy and injuries; physics applied to specific dance movements or styles of dance; equipment (dance shoes, flooring, the barre); and dance of physics.
An
Annus Horribilis
for Anthropology?
Authors: Gibbons Ann
Published: December 2012

It's been a rough year or so for anthropology. After a prominent politician insulted the field, a study announced that graduates with bachelor's degrees in anthropology face a particularly bleak unemployment rate, leading to anthropological career workshops and much discussion.
Snapshots From the Meeting
Authors: Kerr Richard A.
Published: December 2012

These snapshots include new evidence that changes in the appearance of martian gullies from year to year are the result of carbon dioxide frost (aka dry ice) and that geological barriers delayed an earthquake by temporarily holding back injected wastewater from fracking.
Challenge of Chronically Infected Mice with Homologous Trypanosoma cruzi Parasites Enhances the Immune Response but Does Not Modify Cardiopathy: Implications for the Design of a Therapeutic Vaccine
Authors: Rosas-Jorquera Christian Emerson , Sardinha Luiz Roberto , Pretel Fernando Delgado , Bombeiro André Luis , D'Império Lima Maria Regina , Alvarez José Maria
Published: December 2012

Chagas disease is a
Trypanosoma cruzi
-induced zoonosis that has no natural cure. Local damage induced by the parasite and the immune response causes chronic heart and digestive lesions. Efforts to develop a therapeutic vaccine that boosts the immune response to completely clear the parasite are needed because there is no effective treatment for chronically infected patients. In an attempt to modify the host-parasite equilibrium to increase parasite destruction, we analyzed cardiopathy and the immune response in chronically infected mice that were challenged with live homologous parasites. Challenge with a single dose of parasite increased CD4
+
and CD8
+
T cell populations, gamma interferon (IFN-γ) production, and serum-specific IgG levels. However, subpatent parasitemias and cardiac tissue were not affected. Because of the short duration of the immune boost after a single challenge, we next evaluated the impact of four parasite doses, administered 3 weeks apart. At 1 to 2 months after the last dose, the numbers of CD4
+
T cells and IFN-γ-producing CD4
+
memory cells and the CD4
+
T cell proliferative response to
T. cruzi
antigen were increased in the spleen. The frequency of IFN-γ-producing CD8
+
memory cells in the blood was also increased. However, the sustained challenge did not favor TH1 development; rather, it induced an increase in serum-specific IgG1 levels and mixed TH1/TH2 cytokine production. Moreover, there were no significant changes in cardiac lesions and subpatent parasitemias. In conclusion, we believe that this study may help in elucidating the necessary elements for a successful therapeutic vaccine which may reduce cardiomyopathy in chronically infected human patients.
Use of Universal 16S rRNA Gene PCR as a Diagnostic Tool for Venous Access Port-Related Bloodstream Infections
Authors: Guembe M. , Marín M. , Martín-Rabadán P. , Echenagusia A. , Camúñez F. , Rodríguez-Rosales G. , Simó G. , Echenagusia M. , Bouza E.
Published: December 2012

Amplification of the universal 16S rRNA gene using PCR has improved the diagnostic yield of microbiological samples. However, no data have been reported on the reliability of this technique with venous access ports (VAPs). We assessed the utility of 16S rRNA PCR for the prediction of VAP-related bloodstream infection (VAP-RBSI). During a 2-year period, we prospectively received all VAPs removed by interventional radiologists. PCR and conventional cultures were performed using samples from the different VAP sites. We compared the results of PCR with those of conventional culture for patients with confirmed VAP-RBSI. We collected 219 VAPs from 219 patients. Conventional VAP culture revealed 15 episodes of VAP-RBSI. PCR revealed a further 4 episodes in patients undergoing antibiotic therapy which would have gone undetected using conventional culture. Moreover, it had a negative predictive value of 97.8% for the prediction of VAP-RBSI when it was performed using biofilm from the internal surface of the port. In conclusion, universal 16S rRNA PCR performed with samples from the inside of VAPs proved to be a useful tool for the diagnosis of VAP-RBSI. It increased detection of VAP-RBSI episodes by 21.1% in patients undergoing antibiotic therapy whose episodes would have gone undetected using conventional culture. Therefore, we propose a new application of 16S rRNA PCR as a useful tool for the diagnosis of VAP-RBSI in patients receiving antibiotic therapy.
Four-Year Experience with Simultaneous Culture and Shiga Toxin Testing for Detection of Shiga Toxin-Producing Escherichia coli in Stool Samples
Authors: Woo Jennifer S. , Palavecino Elizabeth L.
Published: December 2012

We report our experience with universal Shiga toxin-producing
Escherichia coli
(STEC) screening using culture and Shiga toxin antigen testing over 4 years. Twelve cases were detected—8 detected by both culture and Shiga toxin immunochromatographic assay (IA), 3 by culture, and 1 by IA only. The addition of Shiga toxin testing is of questionable benefit over culture alone for detection of STEC in areas of low prevalence.
Helicobacter pylori Virulence Genes Detected by String PCR in Children from an Urban Community in Northeastern Brazil
Authors: Goncalves Maria H. R. B. , Silva Cícero I. S. M. , Braga-Neto Manuel B. , Fialho Andrea B. C. , Fialho Andre M. N. , Queiroz Dulciene M. M. , Braga Lucia L. B. C.
Published: December 2012

The accuracy of a nested PCR in gastric DNA obtained by a string test for the diagnosis of
Helicobacter pylori
infection in asymptomatic children was 94.0%. The
cagA
-positive toxigenic
vacAs1m1
strains were the most prevalent strains, indicating that this population is colonized early by the strains associated with gastric cancer.
Early Antigen Presentation of Protective HIV-1 KF11Gag and KK10Gag Epitopes from Incoming Viral Particles Facilitates Rapid Recognition of Infected Cells by Specific CD8+T Cells
Authors: Kløverpris Henrik N. , Payne Rebecca P. , Sacha Jonah B. , Rasaiyaah Jane T. , Chen Fabian , Takiguchi Masafumi , Yang Otto O. , Towers Greg J. , Goulder Philip , Prado Julia G.
Published: December 2012

CD8+T cells are major players in antiviral immunity against human immunodeficiency virus type 1 (HIV-1) through recognition of viral epitopes presented on the surface of infected cells. However, the early events involving HIV-1 epitope presentation to CD8+T cells remain poorly understood but are nonetheless crucial for the rapid clearance of virus-infected cells. Here, we comprehensively studied the kinetics of antigen presentation of two protective epitopes, KF11Gag and KK10Gag, restricted by HLA alleles B*57:01 and B*27:05, respectively, and compared these to KY9Pol and VL9Vpr epitopes in a single cycle of HIV-1 replication. We consistently demonstrate differences in epitope presentation kinetics, with very early presentation, within 3 h postinfection, for the protective KF11Gag, KK10Gag epitopes, and KY9Pol but only late presentation for VL9Vpr. We show that this early presentation relies on the antigen being presented from incoming viral particles and is correlated with rapid CD8+T cell activation and clearance of virus-infected cells. Additionally, our data indicate a dose-response dependency between the levels of CD8+T cell activation and the amount of virus inoculum. These data reflect a proof of principle emphasizing the importance of identifying early-presented viral epitopes for rapid elimination of HIV-1-infected cells.
Thoracic endometriosis syndrome manifesting as atraumatic haemothorax causing difficult ventilation under general anaesthesia
Authors: Peterzan Mark , Reynolds Toby , Dulay Kamaljit , Wooldridge Rachel
Published: December 2012

A 31-year-old woman underwent elective hysteroscopy and laparoscopy for investigation of primary infertility. The procedure was abandoned owing to intraoperative desaturation and reduced right-sided chest movement. Postoperative chest x-ray showed an opacified right hemithorax with tracheal deviation to the left. Retrospectively on direct questioning, she admitted to dry cough, mild dyspnoea and significant weight loss. Diagnostic thoracocentesis and contrast CT scan confirmed heavily blood-stained exudative pleural effusion but were otherwise non-diagnostic. After chest drain insertion, 4.6 litre drained but a hydropneumothorax developed upon drain removal, with no improvement on repeat drain insertion. Right video-assisted thoracic surgery was performed, converted to thoracotomy, with repair of diaphragmatic fenestrations, pleurectomy and decortication of trapped lung undertaken. Histological examination of samples of pleura and lung cortex was pathognomic of endometriosis. She was started on norethisterone with no recurrence to date.
Obstructive airway disease and edentulism in the atherosclerosis risk in communities (ARIC) study
Authors: Offenbacher Steven , Beck James D , Barros Silvana P , Suruki Robert Y , Loewy Zvi G
Published: December 2012

Objectives

We examined the potential association between prior chronic obstructive pulmonary disease (COPD) and edentulism, and whether the association varied by COPD severity using data from the Dental Atherosclerosis Risk in Communities Study.

Design

Cross-sectional.

Setting

Community dwelling subjects from four US communities.

Participants and measurements

Cases were identified as edentulous (without teeth) and subjects with one or more natural teeth were identified as dentate. COPD cases were defined by spirometry measurements that showed the ratio of forced expiratory volume (1 s) to vital capacity to be less than 0.7. The severity of COPD cases was also determined using a modified Global Initiative for Chronic Obstructive Lung Disease classification criteria (GOLD stage I–IV). Multiple logistic regression was used to examine the association between COPD and edentulism, while adjusting for age, gender, centre/race, ethnicity, education level, income, diabetes, hypertension, coronary heart disease and congestive heart failure, body mass index, smoking, smokeless tobacco use and alcohol consumption.

Results

13 465 participants were included in this analysis (2087 edentulous; 11 378 dentate). Approximately 28.3% of edentulous participants had prior COPD compared with 19.6% among dentate participants (p<0.0001). After adjustment for potential confounders, we observed a 1.3 (1.08 to 1.62) and 2.5 (1.68 to 3.63) fold increased risk of edentulism among GOLD II and GOLD III/IV COPD, respectively, as compared with the non-COPD/dentate referent. Given the short period of time between the measurements of COPD (visit 2) and dentate status (visit 4) relative to the natural history of both diseases, neither temporality nor insight as to the directionality of the association can be ascertained.

Conclusions

We found a statistically significant association between prior COPD and edentulism, with evidence of a positive incremental effect seen with increasing GOLD classification.
Dying to be famous: retrospective cohort study of rock and pop star mortality and its association with adverse childhood experiences
Authors: Bellis Mark A , Hughes Karen , Sharples Olivia , Hennell Tom , Hardcastle Katherine A
Published: December 2012

Objectives

Rock and pop fame is associated with risk taking, substance use and premature mortality. We examine relationships between fame and premature mortality and test how such relationships vary with type of performer (eg, solo or band member) and nationality and whether cause of death is linked with prefame (adverse childhood) experiences.

Design

A retrospective cohort analysis based on biographical data. An actuarial methodology compares postfame mortality to matched general populations. Cox survival and logistic regression techniques examine risk and protective factors for survival and links between adverse childhood experiences and cause of death, respectively.

Setting

North America and Europe.

Participants

1489 rock and pop stars reaching fame between 1956 and 2006.

Outcomes

Stars’ postfame mortality relative to age-, sex- and ethnicity-matched populations (USA and UK); variations in survival with performer type, and in cause of mortality with exposure to adverse childhood experiences.

Results

Rock/pop star mortality increases relative to the general population with time since fame. Increases are greater in North American stars and those with solo careers. Relative mortality begins to recover 25 years after fame in European but not North American stars. Those reaching fame from 1980 onwards have better survival rates. For deceased stars, cause of death was more likely to be substance use or risk-related in those with more adverse childhood experiences.

Conclusions

Relationships between fame and mortality vary with performers’ characteristics. Adverse experiences in early life may leave some predisposed to health-damaging behaviours, with fame and extreme wealth providing greater opportunities to engage in risk-taking. Millions of youths wish to emulate their icons. It is important they recognise that substance use and risk-taking may be rooted in childhood adversity rather than seeing them as symbols of success.
A pilot study comparing ESO-2 capsule endoscopy with conventional upper endoscopy for the assessment of uncomplicated heartburn and dyspepsia
Authors: Marelli Laura , Jaboli Francesca Maria , Jackson Linda , Palmer Hansa , Erian Gamal , Hamilton Mark , Epstein Owen
Published: December 2012

Background

ESO-2 video capsule endoscopy provides images of the oesophageal mucosa and continues to transmit gastric, and often small bowel images, for up to 30 min. This study compares ESO capsule endoscopy capsule oesophago-gastro-duodenoscopy (Cap-OGD) with conventional endoscopy (OGD).

Methods

50 outpatients with uncomplicated dyspepsia underwent Cap-OGD followed by OGD which was recorded on DVD. Cap-OGD and OGD were each reported independently by two gastroenterologists. A benchmark report was also produced by two gastroenterologists viewing both Cap-OGD and OGD on side-by-side monitors. Major findings included large hiatus hernia, Barrett's oesophagus, oesophagitis, erosive gastritis, tumour and ulceration. Minor findings included histologically-proven superficial gastritis, pouting gastric folds and fundic gland polyps. A questionnaire assessed the patient experience.

Results

49 patients completed the study. In 61%, Cap-OGD transmitted in the duodenum. In the benchmark study, all the major OGD findings were observed on Cap-OGD. Cap-OGD revealed fewer minor findings. When reported independently, Cap-OGD and OGD reports indicated differences in interpretation most marked between the capsule readers with or without previous ESO-2 experience. Patients expressed a clear preference for Cap-OGD.

Conclusions

When compared side-by-side, all the major findings on OGD are seen on Cap-OGD while there is under-reporting of minor findings. Previous experience of ESO-2 capsule reporting improves reading accuracy and indicates the need for training. This pilot study provides a backdrop to explore the possible role of Cap-OGD, especially where patients are reluctant to undergo conventional OGD or where there is risk of prion contamination of the endoscope.
TOWARDS THE DEVELOPMENT OF AGENT-BASED ORGANIZATIONS THROUGH MDD
Authors: AGÜERO JORGE , CARRASCOSA CARLOS , REBOLLO MIGUEL , JULIÁN VICENTE
Published: December 2012

Virtual Organizations are a mechanism where agents can demonstrate their social skills since they can work in a cooperative and collaborative way. Nonetheless, the development of organizations using Multi-Agent Systems (MAS) requires extensive experience in different methodologies and platforms. Model-Driven Development (MDD) is a technique for generating application code that is developed from basic models and meta-models using a variety of automatic transformations. This paper presents an approach to develop and deploy organization-oriented Multi-Agent Systems using a model-driven approach. Based on this idea, we introduce a relatively generic agent-based meta-model for a Virtual Organization, which was created by a comprehensive analysis of the organization-oriented methodologies used in MAS. Following the MDD approach, the concepts and relationships obtained were mapped into two different platforms available for MAS development, allowing the validation of our proposal. In this way, the resultant approach can generate Virtual Organization deployments from unified meta-models, facilitating the development process of agent-based software from the user point of view.
STRUCTURE-LEARNING OF CAUSAL BAYESIAN NETWORKS BASED ON ADJACENT NODES
Authors: LIU XIA , YANG YOULONG , ZHU MINGMIN
Published: December 2012

Due to the infeasibility of randomized controlled experiments, the existence of unobserved variables and the fact that equivalent direct acyclic graphs obtained generally can not be distinguished, it is difficult to learn the true causal relations of original graph. This paper presents an algorithm called BSPC based on adjacent nodes to learn the structure of Causal Bayesian Networks with unobserved variables by using observational data. It does not have to adjust the structure as the existing algorithms FCI and MBCS*, while it can guarantee to obtain the true adjacent nodes. More important is that algorithm BSPC reduces computational complexity and improves reliability of conditional independence tests. Theoretical results show that the new algorithm is correct. In addition, the advantages of BSPC in terms of the number of conditional independence tests and the number of orientation errors are illustrated with simulation experiments from which we can see that it is more suitable in order to learn the structure of Causal Bayesian Networks with latent variables. Moreover a better latent structure representation is returned.
THE HAUSDORFF DIMENSION OF A GRAPH-DIRECTED SET WHOSE UNDERLYING MULTIGRAPH IS A CARTESIAN PRODUCT OR A TENSOR PRODUCT OF MULTIGRAPHS
Authors: DELCROIX STEFAAN , FISHER MICHAEL J.
Published: December 2012

In this paper, we compute the Hausdorff dimension of a graph-directed set when the underlying multigraph is a Cartesian product or a tensor product of several multigraphs. We give explicit formulas in terms of the eigenvalues of the graph and the similarity ratios used with each graph.
CLOSING THE LOOP WITH FRACTAL INTERPOLATING FUNCTIONS FOR GEOPHYSICAL ENCODING
Authors: HUANG HUAI-HSIEN , PUENTE CARLOS E. , CORTIS ANDREA , SIVAKUMAR BELLIE
Published: December 2012

Natural data sets, such as precipitation records, often contain geometries that are too complex to model in their totality with classical stochastic methods. In the past years, we have developed a promising deterministic geometric procedure, the fractal-multifractal (FM) method, capable of generating patterns as projections that share textures and other fine details of individual data sets, in addition to the usual statistics of interest. In this paper, we formulate an extension of the FM method around the concept of "closing the loop" by linking ends of two fractal interpolating functions and then test it on four geometrically distinct rainfall data sets to show that this generalization can provide excellent results.
STORYBOARD OF WCE VIDEO EXTRACTION BASED ON FRAME DIFFERENCE
Authors: FU YANAN , MANDAL MRINAL , ZHANG DAVID W. , MENG MAX Q.-H.
Published: December 2012

Wireless capsule endoscopy (WCE) is an imaging technology that enables close examination of the interior of the entire small intestine. A major problem associated with this new technology is that a large volume of video data need to be examined manually by clinicians. It is therefore useful to design a mechanism that allows the clinicians to gain certain evaluation of a video without watching the whole video. In this paper, a shot detection-based method is presented for automatically establishing the WCE video static storyboard, and then moving storyboard is extracted based on the selected representative frames under the supervision of clinicians. Experimental results show that most of the representative frames containing relevant features can be extracted from the original WCE video. The proposed method can significantly and safely reduce the number of frames that need to be examined by clinicians and thus speed up the diagnosis procedures.
On a Quantum Model of Brain Activities — Distribution of the Outcomes of EEG-Measurements and Random Point Fields
Authors: Fichtner Karl-Heinz , Inoue Kei , Ohya Masanori
Published: December 2012

Considering models based on classical probability theory, states of signals in the brain should be identified with probability distributions of certain random point fields representing the configuration of excited neurons. Then the outcomes of EEG-measurements can be considered as random variables being certain functions of that random point field. In practice, specialists use certain statistical methods evaluating the outcomes of the sequence of these measurements. To make these statistical investigations precise, one should know the distribution of the stochastic process on the space of point configurations representing the time evolution of the configuration of excited neurons in the brain. Up to now that distribution is totally unknown. In this paper we consider time evolutions of random point fields as well as the distribution of the outcomes of EEG-measurements related to unitary evolutions of certain quantum states used in [4, 5, 10 – 14] in order to describe activities of the brain.
Transient reversal of the sodium/calcium exchanger boosts presynaptic calcium and synaptic transmission at a cerebellar synapse
Authors: Roome Chris J. , Power Emmet M. , Empson Ruth M.
Published: December 2012

The sodium/calcium exchanger (NCX) is a widespread transporter that exchanges sodium and calcium ions across excitable membranes. Normally, NCX mainly operates in its “forward” mode, harnessing the electrochemical gradient of sodium ions to expel calcium. During membrane depolarization or elevated internal sodium levels, NCX can instead switch the direction of net flux to expel sodium and allow calcium entry. Such “reverse”-mode NCX operation is frequently implicated during pathological or artificially extended periods of depolarization, not during normal activity. We have used fast calcium imaging, mathematical simulation, and whole cell electrophysiology to study the role of NCX at the parallel fiber-to-Purkinje neuron synapse in the mouse cerebellum. We show that nontraditional, reverse-mode NCX activity boosts the amplitude and duration of parallel fiber calcium transients during short bursts of high-frequency action potentials typical of their behavior in vivo. Simulations, supported by experimental manipulations, showed that accumulation of intracellular sodium drove NCX into reverse mode. This mechanism fueled additional calcium influx into the parallel fibers that promoted synaptic transmission to Purkinje neurons for up to 400 ms after the burst. Thus we provide the first functional demonstration of transient and fast NCX-mediated calcium entry at a major central synapse. This unexpected contribution from reverse-mode NCX appears critical for shaping presynaptic calcium dynamics and transiently boosting synaptic transmission, and is likely to optimize the accuracy of cerebellar information transfer.
Factors Influencing Quality of Life in Caregivers of People with Parkinson's Disease and Implications for Clinical Guidelines
Authors: Morley D. , Dummett S. , Peters M. , Kelly L. , Hewitson P. , Dawson J. , Fitzpatrick R. , Jenkinson C.
Published: December 2012

The quality of life (QoL) of informal caregivers can be adversely affected by a number of factors. This issue, however, has not been well explored for carers of people with Parkinson's (PwP), with research largely restricted to the assessment of caregiver burden and caregiver strain. This study aims to determine the main influences on carer QoL in this population and consider results in the context of current clinical guidelines for the management of Parkinson's disease (PD). Carers completed the newly validated PDQ-Carer, and PwP completed the PDQ-39. The sample comprised 238 carers (mean age 68.20 years) and 238 PwP (mean age 71.64). Results suggest multiple influences on caregiver QoL. These include carer age, gender, health status, and duration of the caregiving role. PwP levels of mobility and cognitive impairment are also significant influences on carer QoL. Not only should practitioners and service providers be particularly aware of the heightened impact of PD on carers over time and as PwP symptoms deteriorate, but this should also be reflected in clinical guidelines for the management of PD.