bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyanobacterial diversity for an anthropogenic impact assessment in the Sør Rondane Mountains area, Antarctica
Authors: Fernández-Carazo Rafael , Namsaraev Zorigto , Mano Marie-Jose , Ertz Damien , Wilmotte Annick
Published: December 2011

The recently inaugurated Belgian Princess Elisabeth Station has been built in the Sør Rondane Mountains (Dronning Maud Land). The construction site is situated close to the Utsteinen Nunatak (71°57′S, 23°20′E), on a granite ridge. Prior to the survey and construction activities, the site had been subject to limited or no direct human impacts. Therefore, a biological inventory has been started for future evaluations of human impacts in the area. This study presents the cyanobacterial diversity of ten samples from the Utsteinen ridge, the Utsteinen Nunatak in the vicinity of the station's site and the more distant Ketelersbreen Dry Valley. All samples were taken before the station was built and were studied by light microscopy and Denaturing Gradient Gel Electrophoresis. Two strains were also isolated. Two different phenol-based extraction methods, with and without detergent-based steps, were tested to improve the quality of molecular detection from these environmental samples. We observed high cyanobacterial diversity (ten morphotypes and 13 operational taxonomic units) in comparison to other Antarctic terrestrial locations and a widespread distribution pattern within the Sør Rondane Mountains area. This might reflect the habitat similarities and/or the easy local dispersal capabilities of microorganisms within the region. The high diversity and proportion of potential endemic (46%) operational taxonomic units, of which 23% were newly described, suggest that this area could have acted as a biological refuge during past glaciations.
SEPSIS IN PREGNANCY
Authors: SUNG EILEEN , GEORGE JULIE , PORTER MICHELLE
Published: December 2011

Sepsis is associated with high morbidity and mortality worldwide. Although, it is not the major reason for intensive care unit admissions during pregnancy, several physiological changes that occur during pregnancy limit the ability of the pregnant woman to compensate for the derangements produced by severe sepsis, often resulting in severe organ dysfunction. Moreover, there are several disorders peculiar to the pregnant state, including preeclampsia, placental abruption, amniotic fluid embolism and postpartum haemorrhage, all of which can produce potentially life-threatening organ failure and may be present concurrently with sepsis contributing to maternal mortality. Evidence-based guidelines advocate assessment and monitoring aimed at early recognition and treatment of sepsis. Early goal-directed therapy, adequate blood glucose control, and corticosteroid replacement when indicated are improving outcomes in patients with severe sepsis, although most of these have not been validated in pregnancy.
Evolution of the QT interval in premature infants: a preliminary study
Authors: Séguéla Pierre-Emmanuel , Rozé Jean-Christophe , Gournay Véronique
Published: December 2011

Background

The association between long QT interval and sudden infant death syndrome has been clearly established. Several studies have been conducted to determine the evolution of the QT interval in childhood from birth, but only in full-term newborns. However, data on the QT interval in pre-term infants are extremely scarce. The objective was to describe the development of the QT interval in premature infants.

Material and methods

In a prospective monocentric study in a neonatal intensive care unit, pre-term newborns born before 37 weeks of gestation without congenital heart disease, family history of long QT, unstable haemodynamic status, or administration of drugs inducing QT interval prolongation were included with parental consent. An electrocardiogram was recorded in similar conditions weekly until discharge in each child. The corrected QT was calculated with Bazett's formula.

Results

In all, 309 echocardiograms were recorded in 87 children, with gestational age ranging from 24–36 weeks. QT first increased after birth in very premature infants – less than 30 weeks of gestation – and then started to decrease, whereas it only decreased in more mature infants. When plotted against postmenstrual age, QT first increased, and then decreased after 32 weeks.

Discussion

Our data suggest that the QT interval varies with postmenstrual age in very premature infants, reaching a peak at 32 weeks. These developmental changes may induce specific vulnerability to QT-lengthening medications in premature infants. This study underlines the need for specific pharmacological studies in this population.
SEARCH, WELFARE, AND THE “HOT POTATO” EFFECT OF INFLATION
Authors: Nosal Ed
Published: December 2011

An increase in inflation causes people to hold smaller real balances and to speed up their spending. Virtually all monetary models capture the first—inflation tax—effect. Few capture the second—hot potato—effect. Those that do associate negative welfare consequences with the hot potato effect. Because both the inflation tax and the hot potato effect imply that inflation has negative effects on welfare, an optimal monetary policy is characterized by the Friedman rule. In the model presented here, there is a hot potato effect, but—all else held constant—the hot potato effect has positive consequences for welfare. As a result, a departure from the Friedman rule can be socially desirable.
Some species tolerate ocean acidification
Authors: Balcerak Ernie
Published: December 2011

Increasing carbon dioxide levels lead to rising ocean acidity, which can harm corals and many other species of ocean life. Acidification causes calcium carbonate, which corals usually need to build skeletons, to dissolve. “Every day, ocean acidification is taking up the weight of 6 million midsize cars' worth of carbon, said Nina Keul, a graduate student at the Alfred Wegener Institute for Polar and Marine Research in Germany during a 7 December press conference at the AGU Fall Meeting. Somewhat surprising, though, is that some species are more tolerant of acidic conditions than scientists had expected. For instance, Keul exposed a species of foraminifera, Ammonia tepida, to seawater with varying acidity and varying carbonate ion concentrations. Previous studies had found that foraminifera growth declined with decreasing carbonate levels, but Keul's foraminifera continued to grow in the acidic conditions. She said that the mechanism that allows this species to tolerate the low carbonate conditions is as yet unknown.
What is the lithosphere‐asthenosphere boundary?
Authors: Dalton Colleen A. , Conrad Clinton P. , Tréhu Anne M.
Published: December 2011

EarthScope Institute on the Lithosphere‐Asthenosphere Boundary; Portland, Oregon, 19–21 September 2011 The lithosphere‐asthenosphere boundary (LAB) marks a pronounced transition in the mechanical behavior of the upper mantle, separating the strong lithosphere from the weak asthenosphere beneath it. Although this boundary is fundamental to scientists' understanding of plate tectonics, identifying which factors (e.g., temperature, melt, volatiles, mineralogy) are responsible for the rheological contrast at the LAB remains a challenge. Recent geophysical and geochemical observations of the uppermost mantle have motivated a new discussion of this fundamental boundary.
How mathematical models can aid understanding of climate
Authors: Williams Paul D. , Cullen Michael J. P. , Huthnance John M.
Published: December 2011

IMA Conference on the Mathematics of the Climate System; Reading, United Kingdom, 13–15 September 2011 About 40 researchers attended a conference by the Institute for Mathematics and its Applications (IMA) to discuss the mathematics of the climate system. The conference focused on the construction and use of mathematical and computational models. The entire hierarchy of models was considered, from the conceptual to the comprehensive. Conceptual models provide understandable paradigms for dynamical climate system behavior, enabling researchers to assess and interpret comprehensive models.
Location prediction of electron TGFs
Authors: Xiong S. , Briggs M. S. , Connaughton V. , Fishman G. J. , Tierney D. , Fitzpatrick G. , Foley S. , Guiriec S. , Holzworth R. H. , Hutchins M. L.
Published: December 2011

Terrestrial Gamma‐ray Flashes (TGFs) are brief pulses of energetic radiation that correlate with thunderstorms and lightning. Most TGFs are observed as gamma‐ray pulses; less frequently they can be observed as electrons and positrons that travel along the geomagnetic field line from the source to the detector. In this paper we predict where electron TGFs should be observed by tracing geomagnetic field lines from likely TGF sources and determining the intersections with satellite orbits. TGF source locations are based upon lightning maps by the Lightning Imaging Sensor (LIS) and the Optical Transient Detector (OTD). Predictions are made both for existing spacecraft with instruments observing TGFs and for other orbits. We compare the predictions to the locations of TGFs that have been observed as electron TGFs. 12 of the 13 known electron TGFs are within the predicted high‐rate regions. Based on the predicted location maps of electron TGFs, we find that electron TGFs should sometimes be observed above areas with low lightning activity and that electron TGFs are best observed at low altitudes (below approximately 1000 km).
Catalysis with Supported Organocatalysts
Authors: toma Štefan
Published: December 2011

Asymmetric organocatalysis is a rapidly growing area of modern organic chemistry. Organocatalysts can be used for electrophilic substitutions in α-position of saturated aldehydes and ketones as well as for nucleophilic additions to nitroethenes and α,β-unsaturated aldehydes and ketones. Organocatalysed cycloadditions are also described. In recent years many papers have been published describing applications of organocatalysts in domino reactions leading to natural products or potential medicaments. Drawbacks of organocatalytic reactions are that higher catalyst loadings must often be used, reactions are rather slow, and must be carried out in organic solvents. The main purpose of this review is to point out that application of unusual solvents, such as water or ionic liquids, as well as unusual conditions, such as microwave irradiation, ultrasonication or ball milling, can have some advantages with organocatalytic reactions.
Enantioselective Catalytic Dendrimers
Authors: J. M. Robertus , Gebbink Klein , Virboul Morgane A. N.
Published: December 2011

The development of chiral transition metal complexes for asymmetric catalysis has seen the concomitant emergence of strategies for their recovery and recyclability in order to render these catalysts economically interesting for industrial applications. In particular, the synthesis of enantioselective metallodendrimers is an interesting approach that combines the advantages of both homogeneous and heterogeneous catalysis without violating the highly active and stereoselective properties of the parent catalyst. In this chapter, a comprehensive overview of the state of the art in enantioselective catalytic dendrimers is given, with an emphasis on the catalytic and recyclability properties of these macromolecules.
Inhibition of soluble epoxide hydrolase by cis-4-[4-(3-adamantan-1-ylureido)cyclohexyl-oxy]benzoic acid exhibits antihypertensive and cardioprotective actions in transgenic rats with angiotensin II-dependent hypertension
Authors: Neckář Jan , Kopkan Libor , Husková Zuzana , Kolář František , Papoušek František , Kramer Herbert J. , Hwang Sung Hee , Hammock Bruce D. , Imig John D. , Malý Jiří , Netuka Ivan , Ošťádal Bohuslav , Červenka Luděk
Published: December 2011

The present study was undertaken to evaluate the effects of chronic treatment with c-AUCB {cis-4-[4-(3-adamantan-1-ylureido)cyclohexyl-oxy]benzoic acid}, a novel inhibitor of sEH (soluble epoxide hydrolase), which is responsible for the conversion of biologically active EETs (epoxyeicosatrienoic acids) into biologically inactive DHETEs (dihydroxyeicosatrienoic acids), on BP (blood pressure) and myocardial infarct size in male heterozygous TGR (Ren-2 renin transgenic rats) with established hypertension. Normotensive HanSD (Hannover Sprague–Dawley) rats served as controls. Myocardial ischaemia was induced by coronary artery occlusion. Systolic BP was measured in conscious animals by tail plethysmography. c-AUCB was administrated in drinking water. Renal and myocardial concentrations of EETs and DHETEs served as markers of internal production of epoxygenase metabolites. Chronic treatment with c-AUCB, which resulted in significant increases in the availability of biologically active epoxygenase metabolites in TGR (assessed as the ratio of EETs to DHETEs), was accompanied by a significant reduction in BP and a significantly reduced infarct size in TGR as compared with untreated TGR. The cardioprotective action of c-AUCB treatment was completely prevented by acute administration of a selective EETs antagonist [14,15-epoxyeicosa-5(Z)-enoic acid], supporting the notion that the improved cardiac ischaemic tolerance conferred by sEH inhibition is mediated by EETs actions at the cellular level. These findings indicate that chronic inhibition of sEH exhibits antihypertensive and cardioprotective actions in this transgenic model of angiotensin II-dependent hypertension.
Analytic derivative couplings between configuration-interaction-singles states with built-in electron-translation factors for translational invariance
Authors: Fatehi Shervin , Alguire Ethan , Shao Yihan , Subotnik Joseph E.
Published: December 2011

We present a method for analytically calculating the derivative couplings between a pair of configuration-interaction-singles (CIS) excited states obtained in an atom-centered basis. Our theory is exact and has been derived using two completely independent approaches: one inspired by the Hellmann-Feynman theorem and the other following from direct differentiation. (The former is new, while the latter is in the spirit of existing approaches in the literature.) Our expression for the derivative couplings incorporates all Pulay effects associated with the use of an atom-centered basis, and the computational cost is minimal, roughly comparable to that of a single CIS energy gradient. We have validated our method against CIS finite-difference results and have applied it to the lowest lying excited states of naphthalene; we find that naphthalene derivative couplings include Pulay contributions sufficient to have a qualitative effect. Going beyond standard problems in analytic gradient theory, we have also constructed a correction, based on perturbative electron-translation factors, for including electronic momentum and eliminating spurious components of the derivative couplings that break translational symmetry. This correction is general and can be applied to any level of electronic structure theory.
Rotationally elastic and inelastic dynamics of NO(X2Π, v = 0) in collisions with Ar
Authors: Paterson G. , Relf A. , Costen M. L. , McKendrick K. G. , Alexander M. H. , Dagdigian P. J.
Published: December 2011

A combined theoretical and experimental study of the depolarization of selected NO(X2Π, v = 0, j, F, ɛ) levels in collisions with a thermal bath of Ar has been carried out. Rate constants for elastic depolarization of rank K = 1 (orientation) and K = 2 (alignment) were extracted from collision-energy-dependent quantum scattering calculations, along with those for inelastic population transfer to discrete product levels. The rate constants for total loss of polarization of selected initial levels, which are the sum of elastic depolarization and population transfer contributions, were measured using a two-color polarization spectroscopy technique. Theory and experiment agree qualitatively that the rate constants for total loss of polarization decline modestly with j, but the absolute values differ by significantly more than the statistical uncertainties in the measurements. The reasons for this discrepancy are as yet unclear. The lack of a significant K dependence in the experimental data is, however, consistent with the theoretical prediction that elastic depolarization makes only a modest contribution to the total loss of polarization. This supports a previous conclusion that elastic depolarization for NO(X2Π) + Ar is significantly less efficient than for the electronically closely related system OH(X2Π) + Ar [P. J. Dagdigian and M. H. Alexander, J. Chem. Phys. 130, 204304 (2009)].
Nuclear magnetic resonance study of alkane conformational statistics
Authors: Burnell E. Elliott , Weber Adrian C. J. , de Lange Cornelis A. , Meerts W. Leo , Dong Ronald Y.
Published: December 2011

NMR spectra of ethane, propane, and n-butane as solutes in the nematic liquid crystals 4-n-pentyl-4′-cyanobiphenyl (5CB) and Merck ZLI 1132 (1132) are investigated over a wide temperature range. The ratios of dipolar couplings of ethane to propane are constant over the entire temperature range. Assuming that this constancy applies to the butane conformers facilitates the separation of probability from order parameter. This separation allows the investigation of conformational distribution without the need of invoking any model for the anisotropic intermolecular potential. The results give an order matrix that is consistent with that predicted from model potentials that describe the orientational potential in terms of short-range size and shape effects. The isotropic intermolecular potential contribution to the trans-gauche energy difference Etg is found to be temperature dependent with the values and variation in agreement with that found when the same results are analyzed using the chord model for anisotropic interactions [A. C. J. Weber and E. E. Burnell, Chem. Phys. Lett. 506, 196 (2011)]. The fit obtained for 9 spectra in 5CB (63 dipolar couplings) has an RMS difference between experimental and calculated dipolar couplings of 2.7 Hz, while that for the 16 spectra in 1132 (112 couplings) is 6.2 Hz; this excellent fit with nine adjustable parameters suggests that the assumption of equal temperature dependencies of the order parameters for ethane, propane, and each conformer of butane is correct. Also the fit parameters (Etg and the methyl angle increase) obtained for 1132 and 5CB agree. The results indicate that the chord model, which was designed to treat hydrocarbon chains, is indeed the model of choice for these chains. The temperature variation of Etg provides a challenge for theoreticians. Finally, even better fits to the experimental dipolar couplings are obtained when the energy in the Boltzmann factor is used for scaling ethane to butane results. However, in this case the values obtained for Etg differ between 1132 and 5CB.
Strain-modulated piezoelectric and electrostrictive nonlinearity in ferroelectric thin films without active ferroelastic domain walls
Authors: Bassiri-Gharb Nazanin , Trolier-McKinstry Susan , Damjanovic Dragan
Published: December 2011

In contrast to usual assumptions, it is shown that even when ferroelastic domain walls are inactive or absent, the motion of ferroelectrically active interfaces in ferroelectric materials contributes, at subcoercive electric fields, not only to the polarization but also to the strain. Specifically, in polycrystalline samples, strain coupling between adjacent grains, or mediated through the substrate in thin films, influences both the dielectric and piezoelectric response. The model developed explains the unexpected observation of piezoelectric nonlinearity in films even in cases in which the domain variants’ projections are equivalent along the direction of the external driving field.
Charge carrier mobility and concentration as a function of composition in AgPO3–AgI glasses
Authors: Rodrigues Ana Candida Martins , Nascimento Marcio Luis Ferreira , Bragatto Caio Barca , Souquet Jean-Louis
Published: December 2011

Conductivity data of the xAgI(1 − x)AgPO3 system (0 ≤ x ≤ 0.5) were collected in the liquid and glassy states. The difference in the dependence of ionic conductivity on temperature below and above their glass transition temperatures (Tg) is interpreted by a discontinuity in the charge carrier's mobility mechanisms. Charge carrier displacement occurs through an activated mechanism below Tg and through a Vogel-Fulcher-Tammann-Hesse mechanism above this temperature. Fitting conductivity data with the proposed model allows one to determine separately the enthalpies of charge carrier formation and migration. For the five investigated compositions, the enthalpy of charge carrier formation is found to decrease, with x, from 0.86 to 0.2 eV, while the migration enthalpy remains constant at ≈0.14 eV. Based on these values, the charge carrier mobility and concentration in the glassy state can then be calculated. Mobility values at room temperature (≈10−4 cm2 V−1 s−1) do not vary significantly with the AgI content and are in good agreement with those previously measured by the Hall-effect technique. The observed increase in ionic conductivity with x would thus only be due to an increase in the effective charge carrier concentration. Considering AgI as a weak electrolyte, the change in the effective charge carrier concentration is justified and is correlated to the partial free energy of silver iodide forming a regular solution with AgPO3.
Influence of the modified Becke-Johnson exchange potential on thermoelectric properties: Application to Mg2Si
Authors: Boulet Pascal , Record Marie-Christine
Published: December 2011

The electronic and transport properties of Mg2Si are calculated using the density-functional and semi-classical Boltzmann transport theories. A detailed comparison of the efficiency of the Perdew, Burke, and Ernzerhof (PBE) and the modified Becke-Johnson (m-BJ) exchange potentials on the prediction of these properties is presented. We show that the m-BJ potential is able to predict the Mg2Si thermoelectric properties with better agreement with the experimental data than the PBE potential. These findings are correlated with a small modification of the valence orbitals of the materials and the opening of the gap.
Investigation of poly(o-anisidine)-SnO2 nanocomposites for fabrication of low temperature operative liquefied petroleum gas sensor
Authors: Patil Dewyani , Kolhe Kishor , Potdar Hari S. , Patil Pradip
Published: December 2011

Poly(o-anisidine)-tin oxide (POA-SnO2) nanocomposites has been investigated for the fabrication of low temperature operative (100 °C) liquefied petroleum gas (LPG) sensor. The POA-SnO2 nanocomposites have been synthesized through an in situ chemical polymerization of o-anisidine in presence of SnO2 nanoparticles. The POA-SnO2 nanocomposite shows better LPG sensing properties than that of pure POA. The nanocomposite with 50 wt. % SnO2 exhibits an excellent LPG sensing characteristics at the operating temperature of 100 °C such as higher relative gas response (∼23.47% to 3.4% of LPG), extremely rapid response (∼6 s), fast recovery (∼33 s), good reproducibility, and remarkable selectivity. The application of POA-SnO2 nanocomposites for fabrication of the LPG sensor was demonstrated.
Multiscale modeling of cross-linked epoxy nanocomposites to characterize the effect of particle size on thermal conductivity
Authors: Yu Suyoung , Yang Seunghwa , Cho Maenghyo
Published: December 2011

A sequential multiscale model to characterize the size effects of nanoparticles on the effective thermal conductivity of SiC/epoxy nanocomposites is developed through non-equilibrium molecular dynamics (NEMD) simulations and continuum micromechanics. Even at the fixed volume fraction condition of a spherical nanoparticle, a significant particle size effect on the thermal conductivity of SiC/epoxy nanocomposites has been demonstrated using NEMD simulations. The main contributions of the particle size dependency are Kapitza thermal resistance at the interface between the particle and matrix, and the formation of highly densified polymer sheathing (adsorption layer) near the particle. To account for these two effects in a continuum regime, both the Kapitza interface and the effective interphase are defined in a micromechanics model, and a four-phase multiscale bridging method is suggested. The thermal conductivity of the effective interphase is implicitly obtained from the four-phase micromechanics model. The accuracy and the relative concentration effect of the particle, Kapitza interface, and the effective interphase are discussed via finite element analysis (FEA). By defining the conductivity of the effective interphase as a function of the particle radius, the proposed bridging model accurately reproduced the particle size dependency observed from NEMD simulations. Using the proposed multiscale model, a parametric study is performed to examine the effect of the Kapitza thermal interface and the effective interphase on the overall thermal conductivity of nanocomposites.
Theory of quantum energy transfer in spin chains: Superexchange and ballistic motion
Authors: Yu Claire X. , Wu Lian-Ao , Segal Dvira
Published: December 2011

Quantum energy transfer in a chain of two-level (spin) units, connected at its ends to two thermal reservoirs, is analyzed in two limits: (i) in the off-resonance regime, when the characteristic subsystem excitation energy gaps are larger than the reservoirs frequencies, or the baths temperatures are low and (ii) in the resonance regime, when the chain excitation gaps match populated bath modes. In the latter case, the model is studied using a master equation approach, showing that the dynamics is ballistic for the particular chain model explored. In the former case, we analytically study the system dynamics utilizing the recently developed Energy-Transfer Born-Oppenheimer formalism [L.-A. Wu and D. Segal, Phys. Rev. E 83, 051114 (2011)]10.1103/PhysRevE.83.051114, demonstrating that energy transfers across the chain in a superexchange (bridge assisted tunneling) mechanism, with the energy current decreasing exponentially with distance. This behavior is insensitive to the chain details. Since at low temperatures the excitation spectrum of molecular systems can be truncated to resemble a spin chain model, we argue that the superexchange behavior obtained here should be observed in widespread systems satisfying the off-resonance condition.
On the role of Coulomb scattering in hafnium-silicate gated silicon n and p-channel metal-oxide-semiconductor-field-effect-transistors
Authors: Thomas S. M. , Prest M. J. , Whall T. E. , Leadley D. R. , Toniutti P. , Conzatti F. , Esseni D. , Donetti L. , Gámiz F. , Lander R. J. P. , Vellianitis G. , Hellström P.-E. , Östling M.
Published: December 2011

In this work, the impact of the local and remote Coulomb scattering mechanisms on electron and hole mobility are investigated. The effective mobilities in quasi-planar finFETs with TiN/Hf0.4Si0.6O/SiO2 gate stacks have been measured at 300 K and 4 K. At 300 K, electron mobility is degraded below that of bulk MOSFETs in the literature, whereas hole mobility is comparable. The 4 K electron and hole mobilities have been modeled in terms of ionized impurity, local Coulomb, remote Coulomb and local roughness scattering. An existing model for remote Coulomb scattering from a polycrystalline silicon gate has been adapted to model remote Coulomb scattering from a high-κ/SiO2 gate stack. Subsequently, remote charge densities of 8 × 1012 cm−2 at the Hf0.4Si0.6O/SiO2 interface were extracted and shown to be the dominant Coulomb scattering mechanism for both electron and hole mobilities at 4 K. Finally, a Monte Carlo simulation showed remote Coulomb scattering was responsible for the degraded 300 K electron mobility.
Developments of scanning probe microscopy with stress/strain fields
Authors: Guo H. X. , Fujita D.
Published: December 2011

An innovative stress/strain fields scanning probe microscopy in ultra high vacuum (UHV) environments is developed for the first time. This system includes scanning tunneling microscope (STM) and noncontact atomic force microscope (NC-AFM). Two piezo-resistive AFM cantilever probes and STM probes used in this system can move freely in XYZ directions. The nonoptical frequency shift detection of the AFM probe makes the system compact enough to be set in the UHV chambers. The samples can be bent by an anvil driven by a step motor to induce stress and strain on their surface. With a direct current (dc) power source, the sample can be observed at room and high temperatures. A long focus microscope and a monitor are used to observe the samples and the operation of STM and AFM. Silicon(111) surface in room temperature and silicon(001) surface in high temperature with stress were investigated to check the performance of the scanning probe microscope.
Long-term frequency stabilization system for external cavity diode laser based on mode boundary detection
Authors: Xu Zhouxiang , Huang Kaikai , Jiang Yunfeng , Lu Xuanhui
Published: December 2011

We have realized a long-term frequency stabilization system for external cavity diode laser (ECDL) based on mode boundary detection method. In this system, the saturated absorption spectroscopy was used. The current and the grating of the ECDL were controlled by a computer-based feedback control system. By checking if there are mode boundaries in the spectrum, the control system determined how to adjust current to avoid mode hopping. This procedure was executed periodically to ensure the long-term stabilization of ECDL in the absence of mode hops. This diode laser system with non-antireflection coating had operated in the condition of long-term mode-hop-free stabilization for almost 400 h, which is a significant improvement of ECDL frequency stabilization system.
One sign ion mobile approximation
Authors: Barbero G.
Published: December 2011

The electrical response of an electrolytic cell to an external excitation is discussed in the simple case where only one group of positive and negative ions is present. The particular case where the diffusion coefficients of the negative ions, Dm, is very small with respect to that of the positive ions, Dp, is considered. In this framework, it is discussed under what conditions the one mobile approximation, in which the negative ions are assumed fixed, works well. The analysis is performed by assuming that the external excitation is sinusoidal with circular frequency ω, as that used in the impedance spectroscopy technique. In this framework, we show that there exists a circular frequency, ω*, such that for ω > ω*, the one mobile ion approximation works well. We also show that for Dm ≪ Dp, ω* is independent of Dm.
Anomalous elastic behavior of relaxor ferroelectric Ca0.28Ba0.72Nb2O6:Ce studied by resonant ultrasound spectroscopy
Authors: Shekhar Pandey Chandra , Schreuer Jürgen , Burianek Manfred , Mühlberg Manfred
Published: December 2011

Elastic behavior of tetragonal tungsten bronze uniaxial relaxor ferroelectric cerium doped Ca0.28Ba0.72Nb2O6 single crystal was investigated employing resonant ultrasound spectroscopy in the temperature range from room temperature up to 1323 K. Doping of cerium lowers the phase transition temperature Tc and Burns temperature Tb significantly, however, intermediate characteristic temperature T* (between the Burns temperature Tb and the temperature of maximum dielectric permittivity Tm) remains same as for pure Ca0.28Ba0.72Nb2O6. All independent elastic constants evolved differently with temperature, reflecting their coupling to different types of the reorientational motion of the polar nanoregions through their interaction with the acoustic waves.
X-ray magnetic circular dichroism of ferromagnetic Co4N epitaxial films on SrTiO3(001) substrates grown by molecular beam epitaxy
Authors: Ito Keita , Harada Kazunori , Toko Kaoru , Ye Mao , Kimura Akio , Takeda Yukiharu , Saitoh Yuji , Akinaga Hiro , Suemasu Takashi
Published: December 2011

5-nm thick Co4N layers capped with 3-nm thick Au layers were grown epitaxially on SrTiO3(001) substrates by molecular beam epitaxy using solid Co and a radio-frequency NH3 plasma. Spin and orbital magnetic moments of the Co4N layers were estimated using x-ray magnetic circular dichroism (XMCD) measurements at 300 K. The site-averaged Co 3d spin magnetic moment is evaluated to be about 1.4 μB, which is smaller than that predicted theoretically (1.58 μB). The element-specific XMCD intensities for the Co L3 edge and N K edge show that the magnetic moment is induced at the N atoms.
Effect of Speed Overestimation on Flash-Lag Effect at Low Luminance
Authors: Vaziri-Pashkam Maryam , Cavanagh Patrick
Published: December 2011

When a brief flash is presented at the same location as a moving object, the flash is perceived to lag behind the moving object to an extent that increases with the speed of the object. Previous studies showed that moving objects appear faster at low luminance as a result of their longer motion trace. Here we examine whether this faster perceived motion also affects the amount of the flash lag at low luminance. We first verified that speed was overestimated at low luminance with our stimulus. We then asked subjects to align a briefly flashed dot with the moving target. Results showed that the flash-lag effect increased with physical speed at both high and low luminance, but there was no additional increase due to the perceived increase of speed at low luminance. We suggest that although motion blur contributes to perceived speed, it does not contribute to the speed information that influences its perceived position.
Spatial analysis of county-based gonorrhoea incidence in mainland China, from 2004 to 2009
Authors: Yin Fei , Feng Zijian , Li Xiaosong
Published: December 2011

Background
Gonorrhoea is one of the most common sexually transmissible infections in mainland China. Effective spatial monitoring of gonorrhoea incidence is important for successful implementation of control and prevention programs. The county-level gonorrhoea incidence rates for all of mainland China was monitored through examining spatial patterns. Methods: County-level data on gonorrhoea cases between 2004 and 2009 were obtained from the China Information System for Disease Control and Prevention. Bayesian smoothing and exploratory spatial data analysis (ESDA) methods were used to characterise the spatial distribution pattern of gonorrhoea cases. Results: During the 6-year study period, the average annual gonorrhoea incidence was 12.41 cases per 100 000 people. Using empirical Bayes smoothed rates, the local Moran test identified one significant single-centre cluster and two significant multi-centre clusters of high gonorrhoea risk (all P-values <0.01). Conclusions: Bayesian smoothing and ESDA methods can assist public health officials in using gonorrhoea surveillance data to identify high risk areas. Allocating more resources to such areas could effectively reduce gonorrhoea incidence.
Syphilis epidemiology and public health interventions in Western Australia from 1991 to 2009
Authors: Kwan Kellie S. H. , Giele Carolien M. , Greville Heath S. , Reeve Carole A. , Lyttle P. Heather , Mak Donna B.
Published: December 2011

Objectives
To describe the epidemiology of congenital and infectious syphilis during 1991–2009, examine the impact of public health interventions and discuss the feasibility of syphilis elimination among Aboriginal people in Western Australia (WA). Methods: WA congenital and infectious syphilis notification data in 1991–2009 and national infectious syphilis notification data in 2005–2009 were analysed by Aboriginality, region of residence, and demographic and behavioural characteristics. Syphilis public health interventions in WA from 1991–2009 were also reviewed. Results: During 1991–2009, there were six notifications of congenital syphilis (50% Aboriginal) and 1441 infectious syphilis notifications (61% Aboriginal). During 1991–2005, 88% of notifications were Aboriginal, with several outbreaks identified in remote WA. During 2006–2009, 62% of notifications were non-Aboriginal, with an outbreak in metropolitan men who have sex with men. The Aboriginal : non-Aboriginal rate ratio decreased from 173 : 1 (1991–2005) to 15 : 1 (2006–2009). Conclusions: These data demonstrate that although the epidemiology of syphilis in WA has changed over time, the infection has remained endemic among Aboriginal people in non-metropolitan areas. Given the continued public health interventions targeted at this population, the limited success in eliminating syphilis in the United States and the unique geographical and socioeconomic features of WA, the elimination of syphilis seems unlikely in this state.
Detection of Viral Hemorrhagic Septicemia Virus by Quantitative Reverse Transcription Polymerase Chain Reaction from Two Fish Species at Two Sites in Lake Superior
Authors: Cornwell Emily R. , Eckerlin Geofrey E. , Getchell Rodman G. , Groocock Geoffrey H. , Thompson Tarin M. , Batts William N. , Casey Rufina N. , Kurath Gael , Winton James R. , Bowser Paul R. , Bain Mark B. , Casey James W.
Published: December 2011

Viral hemorrhagic septicemia virus (VHSV) was first detected in the Laurentian Great Lakes in 2005 during a mortality event in the Bay of Quinte, Lake Ontario. Subsequent analysis of archived samples determined that the first known isolation of VHSV in the Laurentian Great Lakes was from a muskellunge Esox masquinongy collected in Lake St. Clair in 2003. By the end of 2008, mortality events and viral isolations had occurred in all of the Laurentian Great Lakes except Lake Superior. In 2009, a focused disease surveillance program was designed to determine whether VHSV was also present in Lake Superior. In this survey, 874 fish from 7 sites along the U.S. shoreline of Lake Superior were collected during June 2009. Collections were focused on nearshore species known to be susceptible to VHSV. All fish were dissected individually by using aseptic techniques and were tested for the presence of VHSV genetic material by use of a quantitative reverse transcription (qRT) polymerase chain reaction (PCR) targeting the viral nucleoprotein gene. Seventeen fish from two host species at two different sites tested positive at low levels for VHSV. All attempts to isolate virus in cell culture were unsuccessful. However, the presence of viral RNA was confirmed independently in five fish by using a nested PCR that targeted the glycoprotein (G) gene. Partial G gene sequences obtained from three fish were identical to the corresponding sequence from the original 2003 VHSV isolate (MI03) from muskellunge. These detections represent the earliest evidence for the presence of VHSV in Lake Superior and illustrate the utility of the highly sensitive qRT-PCR assay for disease surveillance in aquatic animals.

Received January 30, 2011; accepted July 22, 2011
The lessons learned from the development of the wind energy industry that might be applied to marine industry renewables
Authors: Garrad Andrew
Published: December 2011

This paper considers the early experiences of the development of wind turbines and the wind energy industry in order to try and identify lessons learned that could now be applied to the developing marine renewables technology and industry. It considers both political and commercial incentives and engineering development.
What can wave energy learn from offshore oil and gas?
Authors: Jefferys E. R.
Published: December 2011

This title may appear rather presumptuous in the light of the progress made by the leading wave energy devices. However, there may still be some useful lessons to be learnt from current ‘offshore’ practice, and there are certainly some awful warnings from the past. Wave energy devices and the marine structures used in oil and gas exploration as well as production share a common environment and both are subject to wave, wind and current loads, which may be evaluated with well-validated, albeit imperfect, tools. Both types of structure can be designed, analysed and fabricated using similar tools and technologies. They fulfil very different missions and are subject to different economic and performance requirements; hence ‘offshore’ design tools must be used appropriately in wave energy project and system design, and ‘offshore’ cost data should be adapted for ‘wave’ applications. This article reviews the similarities and differences between the fields and highlights the differing economic environments; offshore structures are typically a small to moderate component of field development cost, while wave power devices will dominate overall system cost. The typical ‘offshore’ design process is summarized and issues such as reliability-based design and design of not normally manned structures are addressed. Lessons learned from poor design in the past are discussed to highlight areas where care is needed, and wave energy-specific design areas are reviewed. Opportunities for innovation and optimization in wave energy project and device design are discussed; wave energy projects must ultimately compete on a level playing field with other routes to low CO
2
energy and/or energy efficiency. This article is a personal viewpoint and not an expression of a ConocoPhillips position.
Wave energy: a Pacific perspective
Authors: Paasch Robert , Ruehl Kelley , Hovland Justin , Meicke Stephen
Published: December 2011

This paper illustrates the status of wave energy development in Pacific rim countries by characterizing the available resource and introducing the region's current and potential future leaders in wave energy converter development. It also describes the existing licensing and permitting process as well as potential environmental concerns. Capabilities of Pacific Ocean testing facilities are described in addition to the region's vision of the future of wave energy.
Laboratory testing the Anaconda
Authors: Chaplin J. R. , Heller V. , Farley F. J. M. , Hearn G. E. , Rainey R. C. T.
Published: December 2011

Laboratory measurements of the performance of the Anaconda are presented, a wave energy converter comprising a submerged water-filled distensible tube aligned with the incident waves. Experiments were carried out at a scale of around 1:25 with a 250 mm diameter and 7 m long tube, constructed of rubber and fabric, terminating in a linear power take-off of adjustable impedance. The paper presents some basic theory that leads to predictions of distensibility and bulge wave speed in a pressurized compound rubber and fabric tube, including the effects of inelastic sectors in the circumference, longitudinal tension and the surrounding fluid. Results are shown to agree closely with measurements in still water. The theory is developed further to provide a model for the propagation of bulges and power conversion in the Anaconda. In the presence of external water waves, the theory identifies three distinct internal wave components and provides theoretical estimates of power capture. For the first time, these and other predictions of the behaviour of the Anaconda, a device unlike almost all other marine systems, are shown to be in remarkably close agreement with measurements.
The use of adrenaline autoinjectors by children and teenagers
Authors: Noimark L. , Wales J. , Du Toit G. , Pastacaldi C. , Haddad D. , Gardner J. , Hyer W. , Vance G. , Townshend C. , Alfaham M. , Arkwright P. D. , Rao R. , Kapoor S. , Summerfield A. , Warner J. O. , Roberts G.
Published: December 2011

Background

Although adrenaline is recommended as first line treatment for anaphylaxis, it is often not utilized. There has been a debate about when adrenaline autoinjectors should be prescribed and how many should be dispensed.

Objectives

To see how many adrenaline autoinjectors were used during anaphylactic reactions and to determine why they were not used in situations where they were clinically indicated.

Methods

Patients were recruited prospectively at 14 paediatric allergy clinics throughout UK. Participants completed a questionnaire covering demographic data, atopic status and details of allergic reactions in the previous year and reasons for using more than one device.

Results

A total of 969 patients were recruited of whom 466 (48.1%, 95% CI: 37.9–58.2) had had at least one reaction in the previous year; 245 (25.3%, 95% CI: 16.2–34.4) of these reactions were anaphylaxis. An adrenaline autoinjector was used by 41 (16.7%, 95% CI: 11.7–21.3) participants experiencing anaphylaxis. Thirteen participants received more than one dose of adrenaline, for nine of these a health professional gave at least one. The commonest reasons for using more than one were severe breathing difficulties (40%), lack of improvement with first dose (20%) and miss‐firing (13.3%). The commonest reasons for not using adrenaline in anaphylaxis were ‘thought adrenaline unnecessary’ (54.4%) and ‘unsure adrenaline necessary’ (19.1%). Many with wheeze did not use their autoinjector.

Conclusions and Clinical Relevance

Adrenaline is used by only a minority of patients experiencing anaphylaxis in the community. Thirteen of the 41 patients with anaphylaxis who used their autoinjector needed another dose of adrenaline. Further research is needed to consider how to best encourage the usage of adrenaline when clinically indicated in anaphylaxis.
Whole blood rotation thromboelastometry (ROTEM®) in nine severe factor V deficient patients and evaluation of the role of intraplatelets factor V
Authors: SPIEZIA L. , RADU C. , CAMPELLO E. , BULATO C. , BERTINI D. , BARILLARI G. , DE ANGELIS V. , PRADELLA P. , ZANON E. , SIMIONI P.
Published: December 2011

Summary.  Severe factor V (FV) deficiency (parahaemophilia) is a rare congenital hemorrhagic disorder characterized by very low or undetectable plasma FV levels and bleeding phenotype ranging from mild to severe. We evaluated whole blood (WB) rotation thromboelastometry (ROTEM) in parahaemophilia patients and the contribution of intraplatelets FV, if any, to clot formation. Standard ROTEM® assays were performed in WB from nine parahaemophilia patients and 50 healthy controls. In addition, platelets poor plasma from one parahaemophilia patient (PPP‐Pt) or normal subjects (PPP‐N) was reconstituted with washed platelets obtained either from one patient with parahaemophilia (Plts‐Pt) or normal subjects (Plts‐N) and ROTEM assays were performed in platelets rich plasma (PRP) samples. There was a prolongation of the WB clotting time (CT) in all assays in patients as compared with controls. However, maximum clot firmness (MCF) was similar in patients and controls. ROTEM in PPP‐Pt showed both a prolongation of CT and a reduction of MCF as compared with PPP‐N. The addition of either Plts‐Pt or Plts‐N to PPP‐Pt resulted in similar increase in MCF and a decrease of CT which was more evident for PPP‐Pt + Plts‐N than PPP‐Pt + Plts‐Pt. In contrast, the addition of Plts‐Pt or Plts‐N to PPP‐N had superimposable effects on both CT and MCF. In parahaemophilia patients, WB ROTEM® presents mainly with prolongation of CT and no relevant effect on MCF. Residual intraplatelets FV in parahaemophilia contributes significantly to thrombin generation as shown in artificially reconstituted PRP models.