bluuebunny/crossref_metadata_2025 huggingface dataset:
Importance of crustal corrections in the development of a new global model of radial anisotropy
Authors: Panning M. P. , Lekić V. , Romanowicz B. A.
Published: December 2010

Accurately inferring the radially anisotropic structure of the mantle using seismic waveforms requires correcting for the effects of crustal structure on waveforms. Recent studies have quantified the importance of accurate crustal corrections when mapping upper mantle structure using surface waves and overtones. Here, we explore the effects of crustal corrections on the retrieval of deep mantle velocity and radial anisotropy structure. We apply a new method of nonlinear crustal corrections to a three‐component surface and body waveform data set and invert for a suite of models of radially anisotropic shear velocity. We then compare the retrieved models against each other and a model derived from an identical data set but using a different nonlinear crustal correction scheme. While retrieval of isotropic structure in the deep mantle appears to be robust with respect to changes in crustal corrections, we find large differences in anisotropic structure that result from the use of different crustal corrections, particularly at transition zone and greater depths. Furthermore, anisotropic structure in the lower mantle, including the depth‐averaged signature in the core‐mantle boundary region, appears to be quite sensitive to choices of crustal correction. Our new preferred model, SAW642ANb, shows improvement in data fit and reduction in apparent crustal artifacts. We argue that the accuracy of crustal corrections may currently be a limiting factor for improved resolution and agreement between models of mantle anisotropy.
Comparing upper tropospheric humidity data from microwave satellite instruments and tropical radiosondes
Authors: Moradi Isaac , Buehler Stefan A. , John Viju O. , Eliasson Salomon
Published: December 2010

Atmospheric humidity plays an important role in the Earth's climate. Microwave satellite data provide valuable humidity observations in the upper troposphere with global coverage. In this study, we compare upper tropospheric humidity (UTH) retrieved from the Advanced Microwave Sounding Unit and the Microwave Humidity Sounder against radiosonde data measured at four of the central facilities of the Atmospheric Radiation Measurement program. The Atmospheric Radiative Transfer Simulator (ARTS) was used to simulate satellite brightness temperatures from the radiosonde profiles. Strong ice clouds were filtered out, as their influence on microwave measurements leads to incorrect UTH values. Day and night radiosonde profiles were analyzed separately to take into account the radiosonde radiation bias. The comparison between radiosonde and satellite is most meaningful for data in cloud‐free, nighttime conditions and with a time difference of less than 2 hr. We found good agreement between the two data sets. The satellite data were slightly moister than the radiosonde data, with a mean difference of 1%–2.3% relative humidity (RH), depending on the radiosonde site. Monthly gridded data were also compared and showed a slightly larger mean difference of up to 3.3% RH, which can be explained by sampling issues.
Hip‐Hop to Health Jr. Obesity Prevention Effectiveness Trial: Postintervention Results
Authors: Fitzgibbon Marian L. , Stolley Melinda R. , Schiffer Linda A. , Braunschweig Carol L. , Gomez Sandra L. , van Horn Linda , Dyer Alan R.
Published: December 2010

The preschool years offer an opportunity to interrupt the trajectory toward obesity in black children. The Hip‐Hop to Health Jr. Obesity Prevention Effectiveness Trial was a group‐randomized controlled trial assessing the feasibility and effectiveness of a teacher‐delivered weight control intervention for black preschool children. The 618 participating children were enrolled in 18 schools administered by the Chicago Public Schools. Children enrolled in the nine schools randomized to the intervention group received a 14‐week weight control intervention delivered by their classroom teachers. Children in the nine control schools received a general health intervention. Height and weight, physical activity, screen time, and diet data were collected at baseline and postintervention. At postintervention, children in the intervention schools engaged in more moderate‐to‐vigorous physical activity (MVPA) than children in the control schools (difference between adjusted group means = 7.46 min/day, P = 0.02). Also, children in the intervention group had less total screen time (−27.8 min/day, P = 0.05). There were no significant differences in BMI, BMI Z score, or dietary intake. It is feasible to adapt an obesity prevention program to be taught by classroom teachers. The intervention showed positive influences on physical activity and screen time, but not on diet. Measuring diet and physical activity in preschool children remains a challenge, and interventions delivered by classroom teachers require both intensive initial training and ongoing individualized supervision.
Design and implementation of a full profile sub-cm ruby laser based Thomson scattering system for MAST
Authors: O’Gorman T. , Mc Carthy P. J. , Prunty S. , Walsh M. J. , Dunstan M. R. , Huxford R. B. , Naylor G. , Maguet Emmanuel , Scannell R. , Shibaev S.
Published: December 2010

A major upgrade to the ruby Thomson scattering (TS) system has been designed and implemented on the Mega-ampere spherical tokamak (MAST). MAST is equipped with two TS systems, a Nd:YAG laser system and a ruby laser system. Apart from common collection optics each system provides independent measurements of the electron temperature and density profile. This paper focuses on the recent upgrades to the ruby TS system. The upgraded ruby TS system measures 512 points across the major radius of the MAST vessel. The ruby laser can deliver one 10 J 40 ns pulse at 1 Hz or two 5 J pulses separated by 100–800 μs. The Thomson scattered light is collected at F/15 over 1.4 m. This system can resolve small (7 mm) structures at 200 points in both the electron temperature and density channels at high optical contrast; ∼50% modulated transfer function. The system is fully automated for each MAST discharge and requires little adjustment. The estimated measurement error for a 7 mm radial point is <4% of \documentclass[12pt]{minimal}\begin{document}$T_e$\end{document}Te and <3% of \documentclass[12pt]{minimal}\begin{document}$n_e$\end{document}ne in the range of 40 eV to 2 keV, for a density of \documentclass[12pt]{minimal}\begin{document}$n_e=2 \times 10^{19}$\end{document}ne=2×1019 m \documentclass[12pt]{minimal}\begin{document}$^{-3}$\end{document}−3. The photon statistics at lower density can be increased by binning in the radial direction as desired. A new intensified CCD camera design allows the ruby TS system to take two snapshots separated with a minimum time of 230 μs. This is exploited to measure two density and temperature profiles or to measure the plasma background light.
Impurities removal by laser blow-off from in-vacuum optical surfaces on RFX-mod experiment
Authors: Alfier A. , Barison S. , Fassina A. , Fiameni S. , Giudicotti L. , Pasqualotto R. , Cervaro V. , Lotto L.
Published: December 2010

An in situ window cleaning system by laser blow-off through optical fiber has been developed on the basis of a feasibility study previously presented. The beam generated by a Q-switched Nd:YAG laser is launched in a vacuum box into a high damage threshold optical fiber through a lens. The fiber output is focused on the impurities-coated surface of a vacuum window exposed to the plasma of the RFX-mod experiment, and it is remotely controlled with an xy motion system to scan the entire surface. We first investigate the energy density threshold necessary to ablate the deposited impurity substrate on removed dirty windows: above threshold, a single laser pulse recovers ∼95% of the window transmission before its exposure to the plasma, while below it the efficiency of the cleaning process is too poor. The system so conceived was then used to clean the three collection windows of the Main Thomson scattering diagnostic on RFX-mod. We also present results obtained applying the same technique to the SiO-protected Al mirror used for the Zeff diagnostic: an energy threshold for efficient impurity removal without mirror damage is first identified, then ablation tests are executed and analyzed in terms of recovered reflectivity. The SIMS technique is used both with windows and mirror to study the composition of surfaces before and after the ablation
A simple protocol for the probability weights of the simulated tempering algorithm: Applications to first-order phase transitions
Authors: Fiore Carlos E. , da Luz M. G. E.
Published: December 2010

The simulated tempering (ST) is an important method to deal with systems whose phase spaces are hard to sample ergodically. However, it uses accepting probabilities weights, which often demand involving and time consuming calculations. Here it is shown that such weights are quite accurately obtained from the largest eigenvalue of the transfer matrix—a quantity straightforward to compute from direct Monte Carlo simulations—thus simplifying the algorithm implementation. As tests, different systems are considered, namely, Ising, Blume–Capel, Blume–Emery–Griffiths, and Bell–Lavis liquid water models. In particular, we address first-order phase transition at low temperatures, a regime notoriously difficulty to simulate because the large free-energy barriers. The good results found (when compared with other well established approaches) suggest that the ST can be a valuable tool to address strong first-order phase transitions, a possibility still not well explored in the literature.
Density functional theory of liquid crystals and surface anchoring: Hard Gaussian overlap-sphere and hard Gaussian overlap-surface potentials
Authors: Avazpour A. , Avazpour L.
Published: December 2010

This article applies the density functional theory to confined liquid crystals, comprised of ellipsoidal shaped particles interacting through the hard Gaussian overlap (HGO) potential. The extended restricted orientation model proposed by Moradi and co-workers [J. Phys.: Condens. Matter 17, 5625 (2005)] is used to study the surface anchoring. The excess free energy is calculated as a functional expansion of density around a reference homogeneous fluid. The pair direct correlation function (DCF) of a homogeneous HGO fluid is approximated, based on the optimized sum of Percus–Yevick and Roth DCF for hard spheres; the anisotropy introduced by means of the closest approach parameter, the expression proposed by Marko [Physica B 392, 242 (2007)] for DCF of HGO, and hard ellipsoids were used. In this study we extend an our previous work [Phys. Rev. E 72, 061706 (2005)] on the anchoring behavior of hard particle liquid crystal model, by studying the effect of changing the particle-substrate contact function instead of hard needle-wall potentials. We use the two particle-surface potentials: the HGO-sphere and the HGO-surface potentials. The average number density and order parameter profiles of a confined HGO fluid are obtained using the two particle-wall potentials. For bulk isotropic liquid, the results are in agreement with the Monte Carlo simulation of Barmes and Cleaver [Phys. Rev. E 71, 021705 (2005)]. Also, for the bulk nematic phase, the theory gives the correct density profile and order parameter between the walls.
Universal coding for transmission of private information
Authors: Datta Nilanjana , Hsieh Min-Hsiu
Published: December 2010

We consider the scenario in which Alice transmits private classical messages to Bob via a classical-quantum channel, part of whose output is intercepted by an eavesdropper Eve. We prove the existence of a universal coding scheme under which Alice's messages can be inferred correctly by Bob, and yet Eve learns nothing about them. The code is universal in the sense that it does not depend on specific knowledge of the channel. Prior knowledge of the probability distribution on the input alphabet of the channel, and bounds on the corresponding Holevo quantities of the output ensembles at Bob's and Eve's end suffice.
Direct observation of iso-frequency contour of surface modes in defective photonic crystals in real space
Authors: Shi Lei , Yin Haiwei , Zhu Xiaolong , Liu Xiaohan , Zi Jian
Published: December 2010

Direct observation of iso-frequency contours of surface modes in defective photonic crystals in real space is demonstrated in a hybrid photonic and plasmonic crystals structure with inevitable defects. The scattering process of by the randomly dispersed defects in periodic structure is analytically discussed and used to explain the reason why defects can induce direct observation of iso-frequency contour in real space. The band-structures are also obtained from the observed iso-frequency contours. The findings in this work can be useful to comprehensively characterize photonic crystals.
Structure of hydrogen-dosed graphene deduced from low electron energy loss characteristics and density functional calculations
Authors: Bangert U. , Pan C. T. , Nair R. R. , Gass M. H.
Published: December 2010

We employed nanometer-scale spatially resolved electron energy loss spectroscopy to monitor the degree and localization of electronic passivation of graphene surfaces by using the π-plasmon as an indicator of sp2-bonding. Upon hydrogenation, the π-plasmon does not vanish, and a new feature at 7 eV occurs in the spectra. This behavior conforms to the theoretical electron energy loss spectra derived from density functional calculations for partial hydrogenation, with benzene rings assuming a corrugated structure. The spatial distribution of the spectral features and atomic resolution Z-contrast images indicate absence of any long-range ordering in the hydrogenated areas.
Improvement of power conversion efficiency of phthalocyanine/C60 heterojunction solar cells by inserting a lithium phthalocyanine layer at the indium-tin oxide/phthalocyanine interface
Authors: Tanaka Senku , Hanada Toshiyuki , Ono Koji , Watanabe Kazuya , Yoshino Katsumi , Hiromitsu Ichiro
Published: December 2010

Improvement of power conversion efficiency of a zinc phthalocyanine (ZnPc)/C60 heterojunction solar cell was achieved by inserting a lithium phthalocyanine (LiPc) layer at the indium-tin oxide (ITO)/ZnPc interface. The results of photoelectron spectroscopy suggest that the barrier height for the hole transport at the ITO/ZnPc interface is reduced by the LiPc layer. A similar improvement of the power conversion efficiency by the insertion of a LiPc layer was also observed in M-phthalocyanine (M=H2, Cu, and TiO)/C60 cells.
A type-II superlattice period with a modified InAs to GaSb thickness ratio for midwavelength infrared photodiode performance improvement
Authors: Rodriguez J. B. , Cervera C. , Christol P.
Published: December 2010

We present a type-II superlattice period with a modified InAs to GaSb thickness ratio for midinfrared detection. In this kind of structure, the large electron-hole wave-function overlap and the low intrinsic carrier concentration lead to a significant signal-to-noise ratio enhancement. For the proof of concept, a sample designed with an InAs to GaSb thickness ratio close to 2 was grown. Comparison with standard design photodiodes shows an improvement of the differential resistance area product by one and a half decade while the quantum efficiency was more than doubled.
Magnetoimpedance sensitive to dc bias current in amorphous microwires
Authors: Ipatov M. , Zhukova V. , Zhukov A. , Gonzalez J.
Published: December 2010

We have investigated the impedance dependence of magnetically soft microwire on the internal circumferential magnetic field HB created by the dc bias current IB and theoretically and experimentally demonstrated that in a conductor with helical magnetic anisotropy, the high frequency impedance depends on the dc bias current IB (or the corresponding bias field HB) and this dependence is hysteretic. We have experimentally observed a change of impedance more than 35% upon changing the bias current. The possible applications of the dc current-driven magnetoimpedance effect are discussed.
Shock-free ferroelectric liquid crystal displays with high optical contrast
Authors: Lapanik V. , Bezborodov V. , Timofeev S. , Haase W.
Published: December 2010

Shock-free ferroelectric liquid crystal displays with high optical contrast and low operating voltage are the concern of this contribution. Ferroelectric liquid crystal compositions with a wide temperature range of the chiral smectic C phase are designed. The influence of the chiral fragments of the molecules, especially their length, on the mechanical stability of the SmC∗ phase has been investigated. The relation between the surface anchoring energy of the aligning polymer and the viscoelastic properties of the SmC∗ phase has been described. Our qualitative model reflects the resistance of the SmC∗ layer structure against mechanical and thermal action.
Performance enhancement of multilevel cell nonvolatile memory by using a bandgap engineered high-κ trapping layer
Authors: Zhu Chenxin , Huo Zongliang , Xu Zhongguang , Zhang Manhong , Wang Qin , Liu Jing , Long Shibing , Liu Ming
Published: December 2010

A high-κ based charge trap flash (CTF) memory structure using bandgap engineered trapping layer HfO2/Al2O3/HfO2 (HAH) has been demonstrated for multilevel cell applications. Compared to a single HfO2 trapping layer, a CTF memory device based on the HAH trapping layer exhibits a larger memory window of 9.2 V, faster program/erase speed, and significantly improved data retention. Enhancements of memory performance and reliability are attributed to the modulation of charge distribution by bandgap engineering in trapping layer. The findings provide a guide for future design of CTF.
Characteristics of efficiency droop in GaN-based light emitting diodes with an insertion layer between the multiple quantum wells and n-GaN layer
Authors: Chang S. P. , Wang C. H. , Chiu C. H. , Li J. C. , Lu Y. S. , Li Z. Y. , Yang H. C. , Kuo H. C. , Lu T. C. , Wang S. C.
Published: December 2010

We have studied the characteristics of efficiency droop in GaN-based light emitting diodes (LEDs) with different kinds of insertion layers (ILs) between the multiple quantum wells (MQWs) layer and n-GaN layer. By using low-temperature (LT) (780 °C) n-GaN as IL, the efficiency droop behavior can be alleviated from 54% in reference LED to 36% from the maximum value at low injection current to 200 mA, which is much smaller than that of 49% in LED with InGaN/GaN short-period superlattices layer. The polarization field in MQWs is found to be smallest in LED with InGaN/GaN SPS layer. However, the V-shape defect density, about 5.3×108 cm−2, in its MQWs region is much higher than that value of 2.9×108 cm−2 in LED with LT n-GaN layer, which will lead to higher defect-related tunneling leakage of carriers. Therefore, we can mainly assign this alleviation of efficiency droop to the reduction of dislocation density in MQWs region rather than the decrease of polarization field.
Electrically pumped ultraviolet random lasing from ZnO films: Compensation between optical gain and light scattering
Authors: Tian Ye , Ma Xiangyang , Jin Lu , Yang Deren
Published: December 2010

We have demonstrated the compensation between optical gain and light scattering in electrically pumped random lasing (RL) from ZnO films through investigating the electroluminescence of MgxZn1−xO/ZnO (x=0.25 and 1) heterostructured devices. As the active ZnO films are sol-gel derived, both heterostructured devices can be electrically pumped into RL at appropriate forward currents. While the active ZnO films are prepared by sputtering, only the MgO/ZnO heterostructured devices can generate RL pumped with sufficient forward currents. It is believed that the light scattering in the sputtered ZnO films is weaker than that in the sol-gel derived ones. However, the inferior light scattering capability of the sputtered ZnO films can be compensated by the MgO/ZnO-heterostructure-enabled higher optical gain in the electrically pumped RL.
Hydrogen storage on calcium-decorated BC3 sheet: A first principles study
Authors: Yang Zailin , Ni Jun
Published: December 2010

Hydrogen storage on the calcium-decorated BC3 sheet is studied by first principles calculations. We find that the Ca atoms can be strongly adsorbed on the BC3 sheet without clustering, which facilitates the reversible hydrogen adsorption and desorption. For one Ca atom adsorbing on the (2×2) BC3 unit cell, each Ca could adsorb up to six hydrogen molecules. By adsorbing Ca atoms on both sides of the BC3 sheet to form a (1×1) pattern, a hydrogen capacity up to 8.4 wt % can be achieved, and the average binding energy of hydrogen molecules adsorbed by Ca atoms is about 0.28 eV.
Bacterial biofilm shows persistent resistance to liquid wetting and gas penetration
Authors: Epstein Alexander K. , Pokroy Boaz , Seminara Agnese , Aizenberg Joanna
Published: December 2010

Most of the world’s bacteria exist in robust, sessile communities known as biofilms, ubiquitously adherent to environmental surfaces from ocean floors to human teeth and notoriously resistant to antimicrobial agents. We report the surprising observation that
Bacillus subtilis
biofilm colonies and pellicles are extremely nonwetting, greatly surpassing the repellency of Teflon toward water and lower surface tension liquids. The biofilm surface remains nonwetting against up to 80% ethanol as well as other organic solvents and commercial biocides across a large and clinically important concentration range. We show that this property limits the penetration of antimicrobial liquids into the biofilm, severely compromising their efficacy. To highlight the mechanisms of this phenomenon, we performed experiments with mutant biofilms lacking ECM components and with functionalized polymeric replicas of biofilm microstructure. We show that the nonwetting properties are a synergistic result of ECM composition, multiscale roughness, reentrant topography, and possibly yet other factors related to the dynamic nature of the biofilm surface. Finally, we report the impenetrability of the biofilm surface by gases, implying defense capability against vapor-phase antimicrobials as well. These remarkable properties of
B. subtilis
biofilm, which may have evolved as a protection mechanism against native environmental threats, provide a new direction in both antimicrobial research and bioinspired liquid-repellent surface paradigms.
Combinatorial library designs for quantifying thin film adhesion via the edge delamination test
Authors: Kim Jae Hyun , Chiang Martin Y M , Kawaguchi Daisuke , Eidelman Naomi , Stafford Christopher M , Moon Chang Kwon
Published: December 2010

We have demonstrated a combinatorial thin film library design for investigating the adhesion between film and substrate as measured by the edge delamination test. This library design allows rapid screening of critical parameters that control thin film reliability and bond strength in films and coatings. Specifically, our library design was aimed at quantifying the effect of film thickness and composition on the interfacial integrity between the film and underlying substrate by applying thermal stress. To create the combinatorial library, a single specimen was fabricated having a thickness gradient of an epoxy film on glass or silicon substrates. After sectioning the film into individual squares, a temperature gradient was applied orthogonal to the thickness gradient to induce debonding events where the adhesion is below a critical value. In addition, another combinatorial library was carried out using the epoxy films with concentration gradient and constant thickness, and applying a constant temperature. The combined results clearly demonstrate that our combinatorial library design and approach provide a large parameter space for accurately and reproducibly mapping the interfacial integrity and bond strength of film/substrate systems.
Adhesion–delamination phenomena at the surfaces and interfaces in microelectronics and MEMS structures and packaged devices
Authors: Khanna V K
Published: December 2010

Physico-chemical mechanisms of adhesion and debonding at the various surfaces and interfaces of semiconductor devices, integrated circuits and microelectromechanical systems are systematically examined, starting from chip manufacturing and traversing the process stages to the ultimate finished product. Sources of intrinsic and thermal stresses in these devices are pointed out. Thin film ohmic contacts to the devices call for careful attention. The role of an adhesion layer in multilayer metallization schemes is highlighted. In packaged devices, sites facing potential risks of delamination are indicated. As MEMS devices incorporate moving parts, there are additional issues due to adhesion of suspended structures to surfaces in the vicinity, both during chip fabrication and their subsequent operation. Proper surface treatments for preventing adhesion together with design considerations for overcoming stiction pave the way to reliable functioning of these devices. Adhesion–delamination issues in microelectronics and MEMS continue to pose significant challenges to both design and process engineers. This paper is an attempt to survey the adhesion characteristics of materials, their compatibilities and limitations and look at future research trends. In addition, it addresses some of the techniques for improved or reduced adhesion, as demanded by the situation. The paper encompasses fundamental aspects to contemporary applications.
Stretching-induced interconnect delamination in stretchable electronic circuits
Authors: van der Sluis O , Hsu Y Y , Timmermans P H M , Gonzalez M , Hoefnagels J P M
Published: December 2010

Stretchable electronics offer increased design freedom of electronic products. Typically, small rigid semiconductor islands are interconnected with thin metal conductor lines on top of, or encapsulated in, a highly compliant substrate, such as a rubber material. A key requirement is large stretchability, i.e. the ability to withstand large deformations during usage without any loss of functionality. Stretching-induced delamination is one of the major failure modes that determines the amount of stretchability that can be achieved for a given interconnect design. During peel testing, performed to characterize the interface behaviour, the rubber is severely lifted at the delamination front while at the same time fibrillation of the rubber at the peel front is observed by ESEM analyses. The interface properties are established by combining the results of numerical simulations and peeling experiments at two distinct scales: the global force–displacement curves and local rubber lift geometries. The thus quantified parameters are used to predict the delamination behaviour of zigzag- and horseshoe-patterned interconnect structures. The accuracy of these finite element simulations is assessed by a comparison of the calculated evolution of the shape of the interconnect structures and the fibrillation areas during stretching with experimental results obtained by detailed in situ analyses.
Adhesive bond testing of carbon–epoxy composites by laser shockwave
Authors: Perton Mathieu , Blouin Alain , Monchalin Jean-Pierre
Published: December 2010

Adhesive bonding, particularly of composite laminates, presents many practical advantages when compared with other joining methods but its use is limited, since there is presently no non-destructive inspection technique to ensure the quality of the bond. We are developing a technique based on the propagation of high amplitude ultrasonic waves to evaluate the adhesive bond strength at high strain rate. Compression waves are generated by a short and powerful laser pulse under water confinement and are converted after reflection on the assembly back surface into tensile waves. The resulting tensile forces normal to the interfaces can cause a delamination inside the laminates or a disbond. The adhesion strength is probed by increasing the laser pulse energy until disbond. A good bond is unaffected by a certain level of stress whereas a weaker one is damaged. The method is shown completely non-invasive throughout the whole composite assembly. The sample back surface velocity is measured by an optical interferometer and used to estimate stress history inside the sample. The depth and size of the disbonds are revealed by a post-test inspection by the well established laser-ultrasonic technique. Experimental results confirmed by numerical simulations show that the proposed method is able to differentiate weak bonds from strong bonds and to estimate quantitatively the bond strength.
Should We Track Migrant Households When Collecting Household Panel Data? Household Relocation, Economic Mobility, and Attrition Biases in the Rural Philippines
Authors: Fuwa Nobuhiko
Published: December 2010

Based on household panel data that tracked migrant households (with an additional survey cost of 17 percent), this article describes behavior of household relocation and quantifies the extent of attrition biases in estimating the determinants of percapita household consumption and of its growth rate. Many households relocate for non‐economic reasons, and to rural destinations, while the small number of urban migrants improved their wellbeing faster than did others. Such heterogeneity among migrants may be a reason behind the negligible attrition biases caused by the omission of migrants, in the inference on the average behavioral coefficients among the original population.
Risk of Burnout in Perioperative Clinicians
Authors: Hyman Steve A. , Michaels Damon R. , Berry James M. , Schildcrout Jonathan S. , Mercaldo Nathaniel D. , Weinger Matthew B.
Published: December 2010

Background

Burnout can lead to health and psychologic problems and is apparently increasing in physicians and nurses. Previous studies have not evaluated all healthcare workers within a single work unit. This study evaluates the risk of burnout in all medical personnel in one perioperative unit.

Methods

We developed an online survey that included demographics, a modified version of the Maslach Burnout Inventory-Human Services Survey, and the Social Support and Personal Coping Survey. Survey constructs (e.g., depersonalization and health) and a global score were calculated. Larger construct and global values were associated with higher risk of burnout. These were separately regressed on role, age, and sex. The global score was then regressed on each of the survey constructs.

Results

Of the 145 responses, 46.2% were physicians (22.8% residents), 43.4% were nurses or nurse anesthetists, and 10.3% were other personnel. After adjusting for sex and age, residents scored higher than other physicians on the following (expected change [95% confidence interval]): global score (1.12 [0.43-1.82]), emotional exhaustion (1.54 [0.44-2.60]), and depersonalization (1.09 [0.23-1.95]). Compared with nonphysicians, residents were 1 U or more higher on these items (P < 0.05 in all cases). Residents had higher health (1.49 [0.48-2.50]) and workload (1.23 [0.07-2.40]) values compared with physicians. Better health, personal support, and work satisfaction scores were related to decreased global scores (P < 0.05).

Conclusions

Physicians (particularly residents) had the largest global burnout scores, implying increased risk of burnout. Improving overall health, increasing personal support, and improving work satisfaction may decrease burnout among perioperative team members.
After 60 years, an answer to the question: what is the Karner blue butterfly?
Authors: Forister Matthew L. , Gompert Zachariah , Fordyce James A. , Nice Chris C.
Published: December 2010

The Karner blue butterfly (KBB),Lycaeides melissa samuelis, is a federally protected taxon whose relationship to the Melissa blue,Lycaeides melissa, has been a point of contention during the 66 years since the KBB was first described. Using a large population-genomic dataset and a model of population divergence with migration, we investigated the relationship between the KBB andL. melissa, as well as the relationship betweenL. melissaand a third taxon,Lycaeides idas. We report that gene flow between the KBB andL. melissais low, and comparable to gene flow betweenL. melissaandL. idas. Considering this population-genetic evidence, we conclude that the KBB is a unique evolutionary lineage that should be recognized asLycaeides samuelis.
Cave men: Stone tools, Victorian science, and the ‘primitive mind’ of deep time
Authors: Pettitt Paul B. , White Mark J.
Published: December 2010

Palaeoanthropology, the study of the evolution of humanity, arose in the nineteenth century. Excavations in Europe uncovered a series of archaeological sediments which provided proof that the antiquity of human life on Earth was far longer than the biblical six thousand years, and by the 1880s authors had constructed a basic paradigm of what ‘primitive’ human life was like. Here we examine the development of Victorian palaeoanthropology for what it reveals of the development of notions of cognitive evolution. It seems that Victorian specialists rarely addressed cognitive evolution explicitly, although several assumptions were generally made that arose from preconceptions derived from contemporary ‘primitive’ peoples. We identify three main phases of development of notions of the primitive mind in the period.
Stress concentrations, diffusionally accommodated grain boundary sliding and the viscoelasticity of polycrystals
Authors: Lee L. C. , Morris S. J. S. , Wilkening J.
Published: December 2010

Using analytical and numerical methods, we analyse the Raj–Ashby bicrystal model of diffusionally accommodated grain-boundary sliding for finite interface slopes. Two perfectly elastic layers of finite thickness are separated by a given fixed spatially periodic interface. Dissipation occurs by time-periodic shearing of the viscous interfacial region, and by time-periodic grain-boundary diffusion. Although two time scales govern these processes, of particular interest is the characteristic time
t
D
for grain-boundary diffusion to occur over distances of order of the grain size. For seismic frequencies
ωt
D
≫1, we find that the spectrum of mechanical loss
Q
−1
is controlled by the local stress field near corners. For a simple piecewise linear interface having identical corners, this localization leads to a simple asymptotic form for the loss spectrum: for
ωt
D
≫1,
Q
−1
∼const.
ω

−
α

. The positive exponent
α
is determined by the structure of the stress field near the corners, but depends both on the angle subtended by the corner and on the orientation of the interface; the value of
α
for a sawtooth interface having 120
°
angles differs from that for a truncated sawtooth interface whose corners subtend the same 120
°
angle. When corners on an interface are not all identical, the behaviour is even more complex. Our analysis suggests that the loss spectrum of a finely grained solid results from volume averaging of the dissipation occurring in the neighbourhood of a randomly oriented three-dimensional network of grain boundaries and edges.
Development of the technology for ‘Diprifusor’ TCI systems
Authors: Gray J. M. , Kenny G. N. C.
Published: December 2010

The availability of fast‐acting intravenous drugs for anaesthesia has encouraged anaesthetists to gain a practical understanding of the pharmacodynamics and pharmacokinetics of these drugs to optimise their administration. ‘Diprifusor’ technology uses pharmacokinetic modelling to control the infusion rate of a pump, providing the anaesthetist with direct control of the blood concentration rather than indirect control by the infusion rate. The ‘Diprifusor’ electronics module is a dual microprocessor component that can be incorporated into an infusion pump to provide this mode of administration. This paper describes the module's infusion control system, prefilled syringe recognition system and the safety aspects addressed by the design.
Pedotransfer functions for estimating total soil nitrogen up to the global scale
Authors: Glendining M. J. , Dailey A. G. , Powlson D. S. , Richter G. M. , Catt J. A. , Whitmore A. P.
Published: December 2010

Realistic model representation of the dynamics of terrestrial ecosystems, including all relevant biophysical and biogeochemical interactions, is a prerequisite to accurate predictions of climate change. However, the current generation of models requires improvement. In particular, it is important to know the nitrogen status of soil for modelling global vegetation and the emission of pollutants such as nitrous oxide. For this reason, we collated several major datasets that record total nitrogen (TN) and other key properties of soils. From these data, we derived pedotransfer functions (PTFs) to predict TN of soils from other soil and site properties using stepwise multiple regressions. The most important predictor was found to be soil organic carbon (SOC). Other helpful soil and site properties for predicting TN included distance from the equator, soil texture class, soil group C:N ratio, pH, % clay and whether the soil contains more or less than 10% SOC. Several different PTFs are presented, giving the user a choice, depending on which soil and site properties are available. In all, we calculated that over 9000 observations were available, although not all datasets contained all the site properties listed above. The most useful PTF was found to be: TN = 0.0232 + 0.0250*C− 0.000534*D + 0.521*G + a(T), for C < 10%, and TN = 0.269 + 0.0449*C− 0.00575*D− 0.157*G + b(T), for C≥10%, where C is % SOC, D is the degrees from the equator, G is a soil group factor defined as (C/Median C:N ratio of soil group), T is a factor based on texture classes (1, 2 or 3), depending on clay and sand content and a takes the value 0.0, 0.0228 or 0.0296 when T is 1, 2 or 3, respectively, and similarly b takes one of the values 0.0, 0.328 or 0.440, respectively. The PTFs were validated against data not used in their derivation, which were held back for this specific purpose. On the basis of the PTF above and the pre‐existing digital soil map of the world, we publish a map of the global distribution of TN. It has been suggested that additional CO2 may be emitted from soils as a result of global warming, exacerbating warming still further. We calculate that the nitrous oxide formed as a result of the nitrogen that also mineralized could contribute a further 30% of additional warming.
Facial lichen nitidus actinicus
Authors: Rashid Dar Nasser , Ullah Rao Sibghat
Published: December 2010

We report an 18‐year‐old woman with lichen nitidus with exclusive facial distribution.
Programming of the renin response to haemorrhage by mild maternal renal impairment in sheep
Authors: Brandon Amanda E , Boyce Amanda C , Lumbers Eugenie R , Kumarasamy Vasumathy , Gibson Karen J
Published: December 2010

1. The aim of the present study was to test the hypothesis that the renin response to mechanisms activated by haemorrhage is programmed by exposure to maternal renal dysfunction.

2. In 26–27‐day‐old lambs born to ewes that had reduced renal function (STNxL, n = 10) and lambs born to ewes with normal renal function (ConL, n = 6), 1.6 mL/kg per min of blood was removed over 10 min.

3. Under basal conditions, the STNxL group had increased mean arterial pressure (P < 0.05). In response to haemorrhage, mean arterial pressure decreased in the STNxL group (P < 0.001), but there was no significant change in the ConL group.

4. Although plasma renin level increased in both groups (P < 0.05), the peak response was reduced and delayed in the STNxL group. In contrast, the rise in arginine vasopressin (AVP) level was similar in both groups and occurred over the same time course. At 24 h, both plasma renin and AVP level were the same as those measured before haemorrhage in both groups. Kidney renin level was similar in the two groups.

5. The attenuated renin response to haemorrhage in the STNxL group might explain the inability to maintain arterial pressure after haemorrhage. The results of the present study suggest that the renin response of the postnatal kidney to reductions in blood volume can be affected by the intrauterine environment. If these changes persist into adulthood, it suggests that permanent programming has occurred. Thus, the ability of an individual to respond to acute severe reductions in blood volume might be determined during intrauterine life.
Diagnosis and management of urinary tract infection in children
Authors: Williams Gabrielle J , Hodson Elisabeth H , Isaacs David , Craig Jonathan C
Published: December 2010

A young child presents to their primary health provider with fever and irritability. How likely is a urinary tract infection? How should a urine sample be collected? How accurate are urinary dipsticks and microscopy compared with culture for the diagnosis? What route and type of antibiotics should be used? What imaging is indicated? Diagnosing and treating children with urinary tract infection presents many questions. This review summarises the most relevant recent primary studies, systematic reviews and guidelines.
The value of computed tomography scanning for the detection of coronary artery disease in patients with idiopathic pulmonary fibrosis
Authors: NATHAN STEVEN D. , WEIR NARGUES , SHLOBIN OKSANA A. , URBAN BRUCE A. , CURRY CHARLENE A. , BASAVARAJ ASHWIN , AHMAD SHAHZAD , KIERNAN JOSEPH , SHERIDAN MICHAEL J. , EARLS JAMES P.
Published: December 2010

Background and objective:  Patients with idiopathic pulmonary fibrosis (IPF) have a higher prevalence of coronary artery disease and this could have an impact on their outcomes. We investigated the predictive ability of coronary artery calcification, assessed by routine CT, which may predict the presence of coronary artery disease.

Methods:  The study cohort consisted of patients with IPF and with left heart catheterization data plus CT scans from July 2003 to July 2008. Grades of coronary calcification on CT were compared with left heart catheterization determination of coronary artery disease.

Results:  There were 57 patients in whom left heart catheterization review demonstrated significant coronary artery disease in 28.1% (16/57), mild disease in 40.3% (23/57) and none in 31.6% (18/57). The median time interval between the catheterization and the reviewed CT scan was 39 days. The sensitivity of moderate to severe calcification for significant coronary artery disease was 81%, while the specificity was 85%, with an associated odds ratio of 25.2 (4.64–166, P < 0.005). There was excellent agreement among three radiologists in the grading of coronary calcification.

Conclusions:  Coronary calcification, as assessed by routine CT of the chest, has very good performance characteristics in predicting underlying significant coronary artery disease in patients with IPF. The routine availability of this study enables the ready screening for coronary artery disease in IPF patients.
Factors associated with hypoxemia in children infected with pandemic H1N1 2009 influenza virus
Authors: Yeom Jung Sook , Park Ji Sook , Seo Ji‐Hyun , Park Eun Sil , Lim Jae‐Young , Park Chan‐Hoo , Woo Hyang‐Ok , Youn Hee‐Shang , Cho Jae Min
Published: December 2010

Background:  Hypoxemia was found to be a major cause of death from pandemic H1N1 2009 influenza (pH1N1) infection. There are limited data on factors associated with hypoxemia in children infected with pH1N1 influenza virus.

Methods:  Factors associated with hypoxemia were investigated using univariate and multivariate analysis in 76 hospitalized pediatric patients with laboratory‐confirmed H1N1 influenza virus infection at Gyeongsang National University Hospital in Jinju, South Korea, from August 2009 to January 2010 by retrospective chart review.

Results:  Hypoxemia occurred in 17 children (22%), of whom three were admitted to an intensive care unit and one died. Hypoxemic patients were significantly more likely to have a higher respiratory rate, pulse rate, white blood cell count (WBC), and C‐reactive protein level, as well as a longer hospital stay. Respiratory rate and WBC count at admission were independently associated with hypoxemia as determined on multivariate analysis, and this association was found to be clinically significant.

Conclusion:  Although a higher WBC count and respiratory rate may not be specific for pHINI but represent the degree of disease severity for any infectious respiratory disease in general, clinicians can use these parameters at admission as useful, early indicators of disease severity in pediatric pH1N1 infection.
Fixed dose (555 MBq; 15 mCi) radioiodine for the treatment of hyperthyroidism: outcome and its predictors
Authors: Gupta S. K. , McGrath S. , Rogers K. , Attia J. , Lewis G. , Viswanathan S. , Saul M. , Allen L.
Published: December 2010

Radioiodine therapy (RIT) is an accepted treatment for hyperthyroidism and a 555‐MBq (15‐mCi) dose is frequently used. We aimed to assess treatment outcome with this dose, and to identify predictors of successful treatment. An analysis of 478 treated patients demonstrated an overall four‐month cure rate of 79.5%; success rate was higher in patients with toxic multinodular goitre, solitary toxic adenoma, a smaller thyroid or less severe disease. This information may be of further assistance if variation in the dose of RIT is considered.
The epidemiology and characteristics of type 2 diabetes in urban, community‐based young people
Authors: Sillars B. A. , Davis W. A. , Kamber N. , Davis T. M. E.
Published: December 2010

As little is known about the impact of type 2 diabetes amongst Australian youth despite international increases in childhood obesity, we aimed to identify and characterize people aged <25 years with type 2 diabetes in an urban community with 60 000 people aged 10–24 years. The estimated maximum prevalence (59/100 000 persons) was lower than US estimates but higher than in Asia and Europe. In eight patients assessed in detail, obesity and related comorbidities were common, and quality of life was low.
SOCIAL CHOICE FROM AN n‐DIMENSIONAL EUCLIDEAN SPACE: A SHORT IMPOSSIBILITY PROOF
Authors: CORAM ALEX , NOAKES LYLE
Published: December 2010

Most presentations of social choice theory are difficult for a non‐specialist to follow. This paper attempts to provide some feel for what is going on by providing a short proof of an impossibility theorem in terms of the techniques that are familiar to political‐economists. We illustrate the advantages of this approach with a short proof of an impossibility theorem.
REGIONAL FINANCE AND REGIONAL DISPARITIES IN CHINA
Authors: PENG JIANGANG , HE JING , LI ZHANGFEI , YI YU , GROENEWOLD NICOLAAS
Published: December 2010

China's growth has recently been spectacularly high but there have been expressions of concern about its uneven regional distribution. It has been asserted that this has been partly due to national financial institutions (mainly state‐owned banks) redirecting deposits from poor to rich regions and that this will be improved by smaller regionally‐focussed institutions. We test these propositions using both informal analysis and more formal econometrics employing recent panel time‐series methods. We find that (i) there is no evidence that deposits are siphoned off from the poor provinces for loans in rich provinces; (ii) financial disparities are positively related to output disparities, (iii) the link is stronger for rural credit co‐operatives than for state‐owned banks and (iv) the relationship is causal in both the long and short runs.