bluuebunny/crossref_metadata_2025 huggingface dataset:
The results of downgrading moderate and severe slipped capital femoral epiphysis by an early Imhauser femur osteotomy
Authors: Witbreuk Melinda M. E. H. , Bolkenbaas M. , Mullender M. G. , Sierevelt I. N. , Besselaar P. P.
Published: September 2009

Purpose

Patients with moderate and severe slipped capital femoral epiphysis (SCFE) develop osteoarthritis earlier in life in association with mechanical impingement.

Methods

To correct deformity and diminish impingement, we performed epiphysiodesis combined with an Imhauser intertrochanteric osteotomy (ITO) in moderate and severe slipped capital femoral epiphysis. We downgraded the angle of the head relative to the acetabulum into an angle corresponding to a mild slip or even an anatomical position. Our hypothesis is that the avoidance of anterior impingement at an early stage can prevent the development of osteoarthritis.

Results

The results of 28 patients (32 hips) were evaluated. Outcome parameters were SF-36, Harris Hip Score, range of motion, Kellgren–Lawrence score, chondrolysis and avascular necrosis. After a median follow-up of 8 (range 2–25) years, the group was clinically, functionally and socially performing well. Radiologically, there was no sign of chondrolysis or avascular necrosis, and more than 80% of the patients did not show any signs of osteoarthritis.

Conclusions

Based on these results, we conclude that a one-stage Imhauser ITO combined with epiphysiodesis performed on patients with moderate and severe SFCE gives satisfactory results.
Ultrasound simulation of peripheral nerves: development of a novel technology for training in regional anaesthesia
Authors: Breitkreutz Raoul , Schellhaas Sebastian , Schmitz-Rixen Thomas , Kessler Paul , Walcher Felix
Published: September 2009

Objective

Regarding education in ultrasound-guided regional anaesthesia, we aimed to develop three-dimensional ultrasound volumes (3D-UV) of peripheral nerves for ultrasound simulation. This study mainly addressed to estimate diagnostic feasibility as well as comparison of original ultrasound images with 3D-UV.

Methods

A free-hand recording system as part of an ultrasound simulation system (Ultrasound simulator Reslice, Schallware GmbH, Berlin, Germany) was coupled to a high-end ultrasound device (Vivid-i, GE healthcare Ultrasound). 3D-UV were recorded as transverse parallel planes from four healthy models and positioned with an electromagnetic tracking system into a mannequin on identical anatomical sites. Using developer software, single B-Mode 3D-UV were combined into 3D-multivolumes (MV). Original short and long axis B-Mode planes were compared with reconstructed planes (reslices).

Results

A total of 108 3D-UV including vessels of carotid region (n = 22), and peripheral nerves of interscalene (31), axillary (28), femoral groin (8) and distal sciatic (19) were recorded. Visual presentation of reconstructed volumes of vessels and peripheral nerves revealed almost comparable quality to the original B-Mode scans of the model examination. Ultrasonographic nerve structure appearance derived from high-resolution ultrasound recordings could be preserved in reslices of 3D-UV and also in part in the long axis.

Conclusions

Our data provide a new proof of concept for ultrasound simulation of peripheral nerves in 3D-ultrasound multivolumes based on high-resolution ultrasound technology. It has the ability to provide pathologic findings and may serve as a powerful method for training in regional anaesthesia and critical care ultrasound.
Continuous intra‐articular infusion of bupivacaine for post‐operative pain relief after total hip arthroplasty: A randomized, placebo‐controlled, double‐blind study
Authors: Chen Dave W. , Hsieh Pang‐Hsin , Huang Kuo‐Chin , Hu Chih‐Chien , Chang Yu‐Han , Lee Mel S.
Published: September 2009

Background: Instillation of local anesthetics into a surgical site has been gaining popularity in post‐operative pain management.

Aim: To determine whether continuous intra‐articular infusion of bupivacaine via pain‐control infusion pumps (PCIP) enhances and sustains analgesia after total hip arthroplasty (THA).

Methods: Ninety‐two patients undergoing THA were randomized to receive continuous intra‐articular infusion of either 0.5% bupivacaine or 0.9% normal saline at a flow rate of 2 mL/h via a PCIP for 48 h. The primary outcome measure was pain intensity on Visual Analogue Scale (VAS) scores in the first 72 h. Other measures included time to first rescue dose of narcotics, amount of narcotic use, presence of adverse events, length of hospital stay, and hip function evaluated with the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index.

Results: Despite a longer time to first narcotic rescue (56 versus 21 min, p < 0.0001) in patients receiving bupivacaine, the two groups did not differ significantly in overall pain relief (p = 0.54). A lower VAS score was found only at time 0 and 2 h; no difference in VAS score was noted at any other time point. Additionally, no difference was found in terms of amount of narcotic use, incidence of adverse events, hospitalization days, and the WOMAC score.

Conclusion: Continuous intra‐articular infusion of 0.5% bupivacaine at 2 mL/h via a PCIP does not provide sustained post‐operative pain relief in patients undergoing THA.
Ultrasound and chronic pain: Innovative approaches
Authors: Siegenthaler Andreas , Curatolo Michele , Eichenberger Urs
Published: September 2009

Ultrasound (US) is an increasingly used imaging technique in interventional pain management. It allows the identification of soft tissues, vessels and nerves, without exposing patients and personnel to radiation. Imaging can be performed continuously and the fluid injected is visualized in a real time fashion. Possible applications are nerve blocks of the cervical and lumbar zygapophysial joints, stellate ganglion block, intercostal and paravertebral nerve blocks, inguinal nerve blocks, occipital nerve blocks, blocks of painful stump neuromas, caudal epidural injections and injections of trigger/tender points. Due to direct nerve visualization, US has a potential application for destructive procedures, such as cryoanalgesia, radiofrequency lesions or chemical neurolysis. Limitations are the poor resolution of narrow‐gauge needles, the loss of resolution with increasing working depth and possible interference of echoes from overlying structures with the image of the target area. US opens new perspectives in interventional pain management. However, there is a need for more clinical trials investigating efficacy and safety of US‐guided pain procedures. Until these studies are completed, US cannot replace fluoroscopy or computed tomography in most interventional pain procedures and remains the domain of well‐trained and experienced physicians. The limited evidence supporting the clinical utility of nerve blocks remains a problem, irrespective of the imaging technique employed.
Vaginal misoprostol for second‐trimester pregnancy termination after one previous cesarean delivery
Authors: Naguib Ahmad H. , Morsi Hassan M. , Borg Tamer F. , Fayed Salah T. , Hemeda Hosam M.
Published: September 2009

Objective

To determine the safety and efficacy of using misoprostol vaginally for second‐trimester abortion in women with a single previous cesarean delivery.

Method

This prospective observational study was carried out at a university hospital in Egypt with 50 pregnant women with 1 previous cesarean delivery; a gestation of at least 16 weeks but less than 20 weeks (group 1) or 20 or more weeks (group 2); and a need to terminate the pregnancy. The regimen was 4 doses of 200 μg of misoprostol applied vaginally every 4 hours daily, with a 12‐hour nightly rest from misoprostol applications, until contractions appeared but not for more than 72 hours. The primary outcome was the induction‐to‐abortion interval.

Results

There were no cases of uterine rupture. Abortion within the study protocol occurred in 45 of the 50 women, for a 90% success rate. There was no significant difference in the induction‐to‐abortion interval between the 2 groups.

Conclusion

Inducing abortion with lower misoprostol doses appear to be safe and effective throughout the second trimester in women with a single previous cesarean delivery. Larger randomized trials are needed to validate these results.
A high-order moment approach for capturing non-equilibrium phenomena in the transition regime
Authors: GU XIAO-JUN , EMERSON DAVID R.
Published: September 2009

The method of moments is employed to extend the validity of continuum-hydrodynamic models into the transition-flow regime. An evaluation of the regularized 13 moment equations for two confined flow problems, planar Couette and Poiseuille flows, indicates some important limitations. For planar Couette flow at a Knudsen number of 0.25, they fail to reproduce the Knudsen-layer velocity profile observed using a direct simulation Monte Carlo approach, and the higher-order moments are not captured particularly well. Moreover, for Poiseuille flow, this system of equations creates a large slip velocity leading to significant overprediction of the mass flow rate for Knudsen numbers above 0.4. To overcome some of these difficulties, the theory of regularized moment equations is extended to 26 moment equations. This new set of equations highlights the importance of both gradient and non-gradient transport mechanisms and is shown to overcome many of the limitations observed in the regularized 13 moment equations. In particular, for planar Couette flow, they can successfully capture the observed Knudsen-layer velocity profile well into the transition regime. Moreover, this new set of equations can correctly predict the Knudsen layer, the velocity profile and the mass flow rate of pressure-driven Poiseuille flow for Knudsen numbers up to 1.0 and captures the bimodal temperature profile in force-driven Poiseuille flow. Above this value, the 26 moment equations are not able to accurately capture the velocity profile in the centre of the channel. However, they are able to capture the basic trends and successfully predict a Knudsen minimum at the correct value of the Knudsen number.
Instabilities in free-surface Hartmann flow at low magnetic Prandtl numbers
Authors: GIANNAKIS D. , ROSNER R. , FISCHER P. F.
Published: September 2009

We study the linear stability of the flow of a viscous electrically conducting capillary fluid on a planar fixed plate in the presence of gravity and a uniform magnetic field, assuming that the plate is either a perfect electrical insulator or a perfect conductor. We first confirm that the Squire transformation for magnetohydrodynamics is compatible with the stress and insulating boundary conditions at the free surface but argue that unless the flow is driven at fixed Galilei and capillary numbers, respectively parameterizing gravity and surface tension, the critical mode is not necessarily two-dimensional. We then investigate numerically how a flow-normal magnetic field and the associated Hartmann steady state affect the soft and hard instability modes of free-surface flow, working in the low-magnetic-Prandtl-number regime of conducting laboratory fluids (Pm ≤ 10−4). Because it is a critical-layer instability (moderately modified by the presence of the free surface), the hard mode exhibits similar behaviour as the even unstable mode in channel Hartmann flow, in terms of both the weak influence of Pm on its neutral-stability curve and the dependence of its critical Reynolds number Rec on the Hartmann number Ha. In contrast, the structure of the soft mode's growth-rate contours in the (Re, α) plane, where α is the wavenumber, differs markedly between problems with small, but non-zero, Pm and their counterparts in the inductionless limit, Pm ↘ 0. As derived from large-wavelength approximations and confirmed numerically, the soft mode's critical Reynolds number grows exponentially with Ha in inductionless problems. However, when Pm is non-zero the Lorentz force originating from the steady-state current leads to a modification of Rec(Ha) to either a sub-linearly increasing or a decreasing function of Ha, respectively for problems with insulating or perfectly conducting walls. In insulating-wall problems we also observe pairs of counter-propagating Alfvén waves, the upstream-propagating wave undergoing an instability driven by energy transferred from the steady-state shear to both of the velocity and magnetic degrees of freedom. Movies are available with the online version of the paper.
Sediment dynamics. Part 2. Dune formation in pipe flow
Authors: OURIEMI MALIKA , AUSSILLOUS PASCALE , GUAZZELLI ÉLISABETH
Published: September 2009

We present a phase diagram of the different dune patterns observed when a bed composed of spherical particles is subjected to a pipe flow. While the threshold for incipient motion is determined by the Shields number, that for dune formation seems to be controlled by the Reynolds number. A simple linear stability analysis based on a particle flux derived by Ouriemi, Aussillous & Guazzelli (J. Fluid Mech., 2009) accounts reasonably well for the experimental observations.
On the stability of shallow rivulets
Authors: BENILOV E. S.
Published: September 2009

We examine the linear stability of a capillary rivulet under the assumption that it is shallow enough to be described by the lubrication approximation. It is shown that rivulets on a sloping plate are stable regardless of their parameters, whereas rivulets on the underside of a plate can be either stable or unstable, depending on their widths and the plate's slope. For the case of a horizontal plate, sufficiently narrow rivulets are shown to be stable and sufficiently wide ones unstable, with the threshold width being π/2(σ/gρ)1/2(ρ and σ are the liquid's density and surface tension, g is the acceleration due to gravity).

It is also shown that, even though the plate's slope induces in a rivulet a sheared flow (which would normally be viewed as a source of instability) – in the present problem, it is a stabilizing factor. The corresponding stability criterion involving the rivulet's width and the plate's slope is computed, and it is demonstrated that, if the latter is sufficiently strong, all rivulets are stable regardless of their widths.
Ernst Freund, Felix Frankfurter, and the AmericanRechtsstaat: A Transatlantic Shipwreck, 1894–1932
Authors: Ernst Daniel R.
Published: September 2009

From the passage of the Interstate Commerce Act of 1887 through the New Deal, American legislators commonly endowed administrative agencies with broad discretionary power. They did so over the objections of an intellectual founder of the American administrative state. The American-born, German-educated lawyer and political scientist Ernst Freund developed an Americanized version of theRechtsstaat—a government bound by fixed and definite rules—in an impressive body of scholarship between 1894 and 1915. In 1920 he eagerly took up an offer from the Commonwealth Fund to finance a comprehensive study of administration in the United States. Here was his chance to show that a Continental version of the Rule of Law had come to America. Unfortunately for Freund, the Commonwealth Fund yoked him to the Austrian-born, American-educated Felix Frankfurter, a celebrant of the enlightened discretion of administrators. Freund's major publication for the Commonwealth Fund,Administrative Powers over Persons and Property(1928), made little impression on scholars of administrative law, who took their lead from Frankfurter. Today theRechtsstaatis largely the beau ideal of libertarian critics of the New Deal; few recognize that it is also part of the diverse legacy of Progressive reform.
Trying to Thread the Needle: The Effects of Redistricting in a Georgia Congressional District
Authors: Hood M. V. , McKee Seth C.
Published: September 2009

In 2005 the Republican-controlled General Assembly redrew Georgia's congressional districts in order to gain additional seats in the 2006 midterm election. In this article we present a case study of the effects of redistricting on turnout and vote choice in Georgia's District 8 in the 2006 U.S. House election. It is apparent both from our findings and an elite interview, that unlike the more aggressive strategy employed by Texas Republicans in 2003, Georgia Republicans tried to thread the needle in their goal of winning District 8. Conventional wisdom suggests that if a political party controls redistricting it will maximize its electoral opportunities. But this was not the case in Georgia.
Economic Crisis and Democracy in Latin America
Authors: Córdova Abby , Seligson Mitchell A.
Published: September 2009

While the world is focused on the economic impact of the financial and credit meltdown, what might be its impact on politics? In well-established democracies, probably not more than elections lost by incumbent parties seen as having mismanaged the economy. But what of consolidating democracies that predominate in the developing world, where some forecasts expect the crisis to hit the poor especially hard? This article uses AmericasBarometer survey data from Latin America and the Caribbean drawn on the eve of the crisis to project how it might affect democracy in the region.
Who SoTLs Where? Publishing the Scholarship of Teaching and Learning in Political Science
Authors: Hamann Kerstin , Pollock Philip H. , Wilson Bruce M.
Published: September 2009

Political science, as a discipline, is a relative newcomer to the Scholarship of Teaching and Learning (SoTL). We examine authorship patterns of SoTL articles in PS: Political Science & Politics, the Journal of Political Science Education, and International Studies Perspectives from 1998–2008. Our findings indicate more collaborative SoTL articles compared to non-SoTL teaching articles. Authorship patterns reveal a relatively high presence of women, assistant professors, and authors housed in Ph.D. and BA departments for SoTL publications. We conclude that SoTL constitutes an important new field of inquiry in the discipline that is likely to become more prominent as a younger cohort of scholars matures.
Evaluation of an EMDR Treatment Outcome Using the Rorschach, the TAT, and the IES-R
Authors: Inoue Naomi
Published: September 2009

In order to better understand treatment outcome through eye movement desensitization and reprocessing (EMDR) trauma therapy, the author conducted comprehensive pre- and posttreatment assessments using the Impact of Event Scale-Revised (IES-R), the Rorschach Comprehensive System (CS), and the Thematic Apperception Test (TAT) on a survivor of human-caused trauma. The results of the Rorschach CS and the TAT showed significant improvements in terms of interpersonal relationships after the treatment. On the other hand, the posttreatment Rorschach scores indicated that the EMDR therapy promoted self-insight in much the same way as a traditional uncovering therapy. In this case study, the findings gained through the two performance-based methods shed light on what a successful EMDR trauma therapy can yield aside from symptom reduction.
Are ocean deserts getting larger?
Authors: Irwin Andrew J. , Oliver Matthew J.
Published: September 2009

The spatial and temporal dynamics of ocean biomes and their provincial subdivisions are affected by the dynamics of Earth's climate system, but the effect of climate change on the distribution and variability of ocean biomes and provinces is largely unknown. A time‐series analysis from multiple satellite platforms shows that the lowest productivity provinces have been growing over the last decade and that the growth rates of these provinces increase as they get larger, and decrease as they get smaller. The most oligotrophic provinces of the ocean grow by reducing the size of the slightly less oligotrophic provinces. As a consequence, while the ocean's most extreme deserts are increasing at an accelerating rate, some oligotrophic areas are simultaneously shrinking. The aggregate area of the oligotrophic provinces oscillated in phase with the Pacific Decadal Oscillation Index from 1998–2007.
Inter‐subunit interaction and quaternary rearrangement defined by the central stalk of prokaryotic V1‐ATPase
Authors: Numoto Nobutaka , Hasegawa Yu , Takeda Kazuki , Miki Kunio
Published: September 2009

V‐type ATPases (V‐ATPases) are categorized as rotary ATP synthase/ATPase complexes. The V‐ATPases are distinct from F‐ATPases in terms of their rotation scheme, architecture and subunit composition. However, there is no detailed structural information on V‐ATPases despite the abundant biochemical and biophysical research. Here, we report a crystallographic study of V1‐ATPase, from Thermus thermophilus, which is a soluble component consisting of A, B, D and F subunits. The structure at 4.5 Å resolution reveals inter‐subunit interactions and nucleotide binding. In particular, the structure of the central stalk composed of D and F subunits was shown to be characteristic of V1‐ATPases. Small conformational changes of respective subunits and significant rearrangement of the quaternary structure observed in the three AB pairs were related to the interaction with the straight central stalk. The rotation mechanism is discussed based on a structural comparison between V1‐ATPases and F1‐ATPases.
Host factors affecting abomasal parasites in Alpine Ibex
Authors: Ceccarelli Roberta , Valenti Valentina , Lanfranchi Paolo , Ferrari Nicola
Published: September 2009

Alpine ibex is characterized by strong sexual differences, both morphological and in population dynamics. Host sex has been shown to strongly affect parasite load with males usually more infected than females. Moreover ibex exhibit a peculiar pattern of survival with subadult males having a slow growing rate coupled with high survival which rapidly decline in old individual. This peculiar life history has been suggested to have been developed as adaptation to an harsh environment. In this way by investing fewer resources in growing the ibex can direct more energy in survival. At the same time the investment in immunodefence can change over the age. To verify the hypothesis that sex and age affect parasite infection, we analysed the abomasal parasite community of swiss ibexes shot during the 2007 hunting season. We analysed the parasite community of 31 abomasa coming from 17 males,12 females, ranging from 1 to 16 years old. The ibex analysed harboured a mean of 1472 helminth/individual. Seven parasites species have been identified with Teladorsagia circumcincta and Marshallagia marshalli covering the 90% of total parasite count. The mean abundance of total parasite count and of M. marshalli was different between sexes, with more parasites found in males. Age alone did not show any significant effect, but its interaction with sex evidenced different relationship such as T. circumcincta increased with age in males and decreased in females.While these data suggest the influence of sex and age on parasitic infection a comparison with other sampling areas, year and season is needed.
Developing an application ontology for annotation of experimental variables – Experimental Factor Ontology
Authors: Malone James , Adamusiak Tomasz , Holloway Ele , Parkinson Helen
Published: September 2009

The Experimental Factor Ontology ("www.ebi.ac.uk/efo":http://www.ebi.ac.uk/efo) is an application focused ontology modelling the experimental factors in ArrayExpress. The ontology has been developed to increase the richness of the annotations that are currently made in the ArrayExpress repository, to promote consistent annotation, to facilitate automatic annotation and to integrate external data. The methodology employed in the development of EFO involves construction of mappings to multiple existing domain specific ontologies, such as the Disease Ontology and Cell Type Ontology.
Current transport and electroluminescence mechanisms in thin SiO2 films containing Si nanocluster-sensitized erbium ions
Authors: Jambois O. , Berencen Y. , Hijazi K. , Wojdak M. , Kenyon A. J. , Gourbilleau F. , Rizk R. , Garrido B.
Published: September 2009

We have studied the current transport and electroluminescence properties of metal oxide semiconductor (MOS) devices in which the oxide layer, which is codoped with silicon nanoclusters and erbium ions, is made by magnetron sputtering. Electrical measurements have allowed us to identify a Poole–Frenkel conduction mechanism. We observe an important contribution of the Si nanoclusters to the conduction in silicon oxide films, and no evidence of Fowler–Nordheim tunneling. The results suggest that the electroluminescence of the erbium ions in these layers is generated by energy transfer from the Si nanoparticles. Finally, we report an electroluminescence power efficiency above 10−3%.
Large area few-layer graphene/graphite films as transparent thin conducting electrodes
Authors: Cai Weiwei , Zhu Yanwu , Li Xuesong , Piner Richard D. , Ruoff Rodney S.
Published: September 2009

By dissolving carbon atoms decomposed from methane in a metal substrate at high temperatures, large area uniform few-layer graphene (FLG)/graphite films were precipitated on metal surfaces upon cooling. The thickness could be controlled by varying the amount of carbon atoms in the metal. Such films were transferred to glass slides after dissolving the metal substrate in an aqueous solution of Fe(NO3)3. Sheet resistances as low as 200 Ω/◻ with a transmittance of 85% were obtained from FLG films. The resistance and transmittance can be changed over one order of magnitude, making such films potentially useful for transparent thin conducting electrodes.
An energy-based model to predict wear in nanocrystalline diamond atomic force microscopy tips
Authors: Agrawal R. , Moldovan N. , Espinosa H. D.
Published: September 2009

Atomic force microscopy (AFM) is one of the most powerful techniques to probe surfaces and material properties at the nanoscale, and pattern organic and inorganic molecules. In all cases, knowledge of the tip geometry and its evolution with continued use is essential. In this work, a broadly applicable energy model for the evolution of scanning probe tip radii during use is presented based on quantitative wear experiments. Experiments were conducted using AFM probes made of both undoped and nitrogen-doped diamond. Undoped diamond probes were found to be nearly ten times more wear resistant than commercially available silicon nitride probes. For a constant applied force, a linear relationship between wear volume and total dissipation energy is identified. The change in tip radius was also found to be proportional to the square root of scan distance, x0.5.
Fixed photorefractive holograms with maximum index-of-refraction modulation in LiNbO3:Fe
Authors: Jerez Vladimir A. , de Oliveira Ivan , Frejlich Jaime
Published: September 2009

We report the recording of a fixed good quality transmission hologram in LiNbO3:Fe with maximum index-of-refraction modulation using the simultaneous recording/compensation process at 120 °C in a specially designed setup with λ=514.5 nm. This process was shown to be reproducible and in good agreement with an already reported theoretical model. The analysis of this recording process showed that material saturation was reached so that the maximum possible fixed index-of-refraction modulation was achieved. From the comparison of theoretical and experimental recording/compensation process data some material parameters (dielectric relaxation time τMe≈15 min, saturation space-charge field Eq=18.8 kV/cm, and photovoltaic-to-saturation field ratio Eph/Eq=0.80) were determined. The diffraction efficiency of this grating was measured using a λ=633 nm probe laser beam in an independent setup and its actual value computed, taking into account the angular divergence of the probe beam. The good grating performance as an optical Bragg filter was experimentally characterized by independently measuring its angular (approximately 1.2 mrad) and spectral (approximately 0.1 nm) selectivities, both at the probe beam wavelength of 633 nm.
Infrared multiphoton electron detachment spectroscopy of C762−
Authors: Hampe O. , Neumaier M. , Boese A. D. , Lemaire J. , Niedner-Schatteburg G. , Kappes M. M.
Published: September 2009

In this letter, we report the first infrared spectrum of C762−. This multiply charged anion has been studied in an electrodynamic ion trap held at room temperature using tunable infrared radiation from a free-electron laser. Resonant vibrational excitation is found to cause electron detachment and the resulting singly negatively charged as well as the remaining doubly charged parent ion are monitored as a function of IR wavelength in an experimental scheme that we term infrared multiphoton electron detachment spectroscopy. The obtained IR spectra are contrasted to computed vibrational spectra using density functional theory. The dianionic molecule retains its overall symmetry (i.e., D2 point group) with a A11 ground state with respect to the neutral fullerene. Spectral shifts of characteristic tangential modes relative to the neutral cage are shown to originate from the excess charge density.
Determination of magnetic anisotropies, interlayer coupling, and magnetization relaxation in FeCoB/Cr/FeCoB
Authors: Gong Y. , Cevher Z. , Ebrahim M. , Lou J. , Pettiford C. , Sun N. X. , Ren Y. H.
Published: September 2009

We studied magnetic anisotropic properties, interlayer coupling, and spin wave relaxation in ten periods of CoFeB/Cr/CoFeB films grown on seed layers of Cu with a Co:Fe:B composition ratio of 2:2:1. The measurements were taken in samples with 50 Å layers of CoFeB using the ferromagnetic resonance technique. The thickness of the Cr interlayers was varied from 4 to 40 Å for understanding the mechanisms of interlayer coupling. We investigated the magnetic anisotropy parameters by rotating the sample with respect to the microwave magnetic field from in plane to perpendicular to the plane. We identify both the acoustic branch and the optical branch in the spin wave resonance spectra. The effective interlayer coupling constant and the out-of-plane anisotropy show an oscillatory change, while the uniaxial in-plane anisotropy increases monotonically with increasing the thickness of the spacing layers. Moreover, we show that the spin wave relaxation can be optimized by adjusting the interlayer exchange interactions.
Nanoscale liquid-vapor phase-change physics in nonevaporating region at the three-phase contact line
Authors: Maroo Shalabh C. , Chung J. N.
Published: September 2009

Nanoscale liquid film evaporation is usually associated with super-high heat transport rates and can be found in natural processes and in many industrial and advanced technologies. In this paper, thin film evaporation is simulated in a nanochannel using molecular dynamics to study the effect of varying nanochannel height and film thickness. Three nanochannel heights (16.32, 25.5, and 35.7 nm; constant liquid film thickness=3 nm) and three liquid film thicknesses (2, 4, and 6 nm; constant nanochannel height=25.5 nm) are simulated to study six cases. A nonevaporating film is obtained for all six cases. Hamaker constant, vapor pressure, film thickness, and net evaporation and heat fluxes are evaluated. An additional simulation (case 7) is run with simultaneous evaporation-condensation; no nonevaporating film is obtained. Thus, the creation of a nonevaporating film, and its thickness (if the film forms), depends on the combination of three factors, namely, vapor pressure, substrate temperature, and solid-liquid molecular interaction strength.
Magnetic, magnetocaloric, and magnetoelastic properties of LaFe11.57Si1.43Bx compounds
Authors: Pathak Arjun K. , Basnyat Prakash , Dubenko Igor , Stadler Shane , Ali Naushad
Published: September 2009

We have studied the magnetic, magnetocaloric, and magnetoelastic properties of LaFe11.57Si1.43Bx compounds in the concentration interval 0<x≤1.64 using magnetization and strain gauge techniques. The crystal cell parameters and Curie temperatures were found to increase linearly with increasing B concentrations up to ∼0.1% and 9%, respectively. A positive magnetovolume anomaly of about 0.22% was observed in the vicinity of TC. The magnetovolume coupling constant was estimated to be approximately 3×10−3 [μB/Fe atom]−2. Magnetic entropy changes at TC slightly depended on B concentration. A hysteresis loss of about ten times smaller relative to the base compound (x=0) was observed for x=1.64. Therefore it was shown that the characteristics of the magnetocaloric effect of LaFe11.57Si1.43 can be adjusted by a change in B concentration in the LaFe11.57Si1.43Bx system. The relative importance of the variation in the volume of crystal cell and electron concentration on TC was discussed.
Temperature dependence and screening models in quantum cascade structures
Authors: Nelander Rikard , Wacker Andreas
Published: September 2009

Different screening models in quantum cascade lasers are compared by calculating the contribution of intrasubband impurity scattering to the optical linewidth as a function of temperature. We find a strong impact of impurity scattering, which increases substantially with temperature. A simple isotropic bulk screening model works well if the screening length is of the order of or longer than the period length of the cascade structure.
Effective-mode representation of non-Markovian dynamics: A hierarchical approximation of the spectral density. II. Application to environment-induced nonadiabatic dynamics
Authors: Hughes Keith H. , Christ Clara D. , Burghardt Irene
Published: September 2009

The non-Markovian approach developed in the companion paper [Hughes et al., J. Chem. Phys. 131, 024109 (2009)], which employs a hierarchical series of approximate spectral densities, is extended to the treatment of nonadiabatic dynamics of coupled electronic states. We focus on a spin-boson-type Hamiltonian including a subset of system vibrational modes which are treated without any approximation, while a set of bath modes is transformed to a chain of effective modes and treated in a reduced-dimensional space. Only the first member of the chain is coupled to the electronic subsystem. The chain construction can be truncated at successive orders and is terminated by a Markovian closure acting on the end of the chain. From this Mori-type construction, a hierarchy of approximate spectral densities is obtained which approach the true bath spectral density with increasing accuracy. Applications are presented for the dynamics of a vibronic subsystem comprising a high-frequency mode and interacting with a low-frequency bath. The bath is shown to have a striking effect on the nonadiabatic dynamics, which can be rationalized in the effective-mode picture. A reduced two-dimensional subspace is constructed which accounts for the essential features of the nonadiabatic process induced by the effective environmental mode. Electronic coherence is found to be preserved on the shortest time scale determined by the effective mode, while decoherence sets in on a longer time scale. Numerical simulations are carried out using either an explicit wave function representation of the system and overall bath or else an explicit representation of the system and effective-mode part in conjunction with a Caldeira–Leggett master equation.
The effect of absorber doping on electrical and optical properties of nBn based type-II InAs/GaSb strained layer superlattice infrared detectors
Authors: Myers Stephen , Plis Elena , Khoshakhlagh Arezou , Kim Ha Sul , Sharma Yagya , Dawson Ralph , Krishna Sanjay , Gin Aaron
Published: September 2009

We have investigated the electrical and optical properties of a nBn based InAs/GaSb strained layer superlattice detector as a function of absorber region background carrier concentration. Temperature dependent dark current, responsivity, and detectivity were measured. The device with a nonintentionally doped absorption region demonstrated the lowest dark current density with a specific detectivity at zero bias equal to 1.2×1011 cm Hz1/2/W at 77 K. This value decreased to 6×1010 cm Hz1/2/W at 150 K. This contrasts significantly with p-i-n diodes, in which the D∗ decreases by over two orders of magnitude from 77 to 150 K, making nBn devices promising for higher operating temperatures.
Simulation of dilute solutions of linear and star-branched polymers by dissipative particle dynamics
Authors: Nardai M. M. , Zifferer G.
Published: September 2009

A most promising off-lattice technique in order to simulate not only static but in addition dynamic behavior of linear and star-branched chains is the dissipative particle dynamics (DPD) method. In this model the atomistic representation of polymer molecules is replaced by a (coarse-grained) equivalent chain consisting of beads which are repulsive for each other in order to mimic the excluded volume effect (successive beads in addition are linked by springs). Likewise solvent molecules are combined to beads which in turn are repulsive for each other as well as for the polymer segments. The system is relaxed by molecular dynamics solving Newton’s laws under the influence of short ranged conservative forces (i.e., repulsion between nonbonded beads and a proper balance of repulsion and attraction between bonded segments) and dissipative forces due to friction between particles, the latter representing the thermostat in conjunction with proper random forces. A variation of the strength of the repulsion between different types of beads allows the simulation of any desired thermodynamic situation. Static and dynamic properties of isolated linear and star-branched chains embedded in athermal, exothermal, and endothermal solvent are presented and theta conditions are examined. The generally accepted scaling concept for athermal systems is fairly well reproduced by linear and star-branched DPD chains and theta conditions appear for a unique parameter independent of functionality as in the case of Monte Carlo simulations. Furthermore, the correspondence between DPD and Monte Carlo data referring to the shape of chains and stars is fairly well, too. For dilute solutions the Zimm behavior is expected for dynamic properties which is indeed realized in DPD systems.
Band dispersion of quasi-single crystal thin film phase pentacene monolayer studied by angle-resolved photoelectron spectroscopy
Authors: Ohtomo Manabu , Suzuki Tadamasa , Shimada Toshihiro , Hasegawa Tetsuya
Published: September 2009

Intermolecular band dispersion of thin film phase pentacene grown epitaxially on step-bunched 3×3 Bi–Si(111) was investigated using angle resolved photoemission spectroscopy at 130 K. We evaluated the transfer integrals using two-dimensional tight-binding fit to the experimental dispersion and found that adjacent molecules in Γ-M direction have the strongest coupling as predicted. The estimated effective mass at the top of the valence band was isotropic and ranged between 0.8 and 1.0 of the electron mass.
Three-dimensional simulations of a thin film heterojunction solar cell with a point contact/defect passivation structure at the heterointerface
Authors: Allsop N. , Nürnberg R. , Lux-Steiner M. Ch. , Schedel-Niedrig Th.
Published: September 2009

Thin film heterojunction solar cells such as those based on the chalcopyrites or amorphous silicon are often limited by interface recombination at the active heterointerface. A new strategy to overcome this limitation is described, replacing the conventional wider band gap contact material with a combination of a passivation layer plus the conventional contact in a point contact type structure. This is similar to the established method to minimize rear contact recombination in crystalline silicon solar cells. Here point contacts at the heterointerface of a CuInS2 based solar cell are modeled using the WIAS-TeSCA code. The importance of the donor defect energy level at the absorber/passivation interface is shown, and a way to improve the cell efficiency by >25% (relative) is outlined.
Plasma physics in noninertial frames
Authors: Thyagaraja A. , McClements K. G.
Published: September 2009

Equations describing the nonrelativistic motion of a charged particle in an arbitrary noninertial reference frame are derived from the relativistically invariant form of the particle action. It is shown that the equations of motion can be written in the same form in inertial and noninertial frames, with the effective electric and magnetic fields in the latter modified by inertial effects associated with centrifugal and Coriolis accelerations. These modifications depend on the particle charge-to-mass ratio, and also the vorticity, specific kinetic energy, and compressibility of the frame flow. The Newton–Lorentz, Vlasov, and Fokker–Planck equations in such a frame are derived. Reduced models such as gyrokinetic, drift-kinetic, and fluid equations are then derivable from these equations in the appropriate limits, using standard averaging procedures. The results are applied to tokamak plasmas rotating about the machine symmetry axis with a nonrelativistic but otherwise arbitrary toroidal flow velocity. Astrophysical applications of the analysis are also possible since the power of the action principle is such that it can be used to describe relativistic flows in curved spacetime.
Fostering Private – Public Partnerships in the Transition Economies: Helcom as a System of Implementation Review
Authors: Trumbull Nathaniel
Published: September 2009

Economic chaos, legislative and regulatory turmoil, and institutional upheaval have presented significant challenges for environmental protection implementation during the transition period of the formerly centrally planned economies. Russia's efforts to achieve compliance with Helsinki Commission (HELCOM) environmental guidelines are examined from the perspective of water resources planning in St Petersburg, the largest urban polluting source on the Baltic Sea. I focus on the case of the first private – public partnership at a public water authority in Russia. Water resources planning in St Petersburg is analyzed through the lens of the theoretical framework of systems of implementation review in order to assess how socioeconomic, institutional, and management changes have shaped water resources planning and environmental protection implementation in a transition economy. The broader issue of accumulation of social capital with foreign donors and investors is an important part of the pursuit of HELCOM compliance and environmental protection implementation by St Petersburg's city leaders and managers.
A robust method for searching the smallest set of smallest rings with a path-included distance matrix
Authors: Lee Chang Joon , Kang Young-Mook , Cho Kwang-Hwi , No Kyoung Tai
Published: September 2009

The perception of rings in graphs is widely used in many fields of science and engineering. Algorithms developed in the chemistry community, called smallest set of smallest rings (SSSR), applicable only for simple graphs or chemical structures. In contrast, algorithms developed by the computer science community, called minimum cycle basis (MCB) are identical to SSSR yet exhibit greater robustness. MCB-based algorithms can correctly reveal all rings in any complex graph. However, they are slow when applied to large complex graphs due to the inherent limitations of the algorithms used. Here, we suggest a heuristic method called RP-Path. This method is a robust, simple, and fast search method with
O
(
n
3
) runtime algorithm that correctly identifies the SSSR of all of the test case of complex graphs by using approach different from the MCB-based method. Both the robustness and improvement in speed are achieved by using a path-included distance matrix and describing the characteristic features of rings in the matrix. This method is accurate and faster than any other methods and may find many application in various fields of science and engineering that use complicated graphs with thousands of nodes.
The conserved Est1 protein stimulates telomerase DNA extension activity
Authors: DeZwaan Diane C. , Freeman Brian C.
Published: September 2009

The first telomerase cofactor identified was the budding yeast protein Est1, which is conserved through humans. While it is evident that Est1 is required for telomere DNA maintenance, understanding its mechanistic contributions to telomerase regulation has been limited. In vitro, the primary effect of Est1 is to activate telomerase-mediated DNA extension. Although Est1 displayed specific DNA and RNA binding, neither activity contributed significantly to telomerase stimulation. Rather Est1 mediated telomerase upregulation through direct contacts with the reverse transcriptase subunit. In addition to intrinsic Est1 functions, we found that Est1 cooperatively activated telomerase in conjunction with Cdc13 and that the combinatorial effect was dependent upon a known salt-bridge interaction between Est1 (K444) and Cdc13 (E252). Our studies provide insights into the molecular events used to control the enzymatic activity of the telomerase holoenzyme.
From rhetoric to reality: The problematic nature and assessment of children and young people's social and emotional learning
Authors: Watson Deborah Lynette , Emery Carl
Published: September 2009

There is little doubt of the educational and social merits of developing children and young people's social and emotional capabilities. But there lacks consensus on what these capabilities are; what should be assessed or shown to have developed over time; and the most appropriate methods for doing this. Through the conceptual framework of ‘social and emotional dispositions and skills’ (SEDS), and based on research in Wales, we present the argument for an alternative assessment methodology designed to challenge dominant discourses in the field and present a ‘minoritarian’ perspective of children and young people's social and emotional learning. The intention of this paper is to present a rationale for the co‐construction of an understanding of the concept of SEDS and engage in critical debate with researchers and practitioners from a wide range of services for children and young people.
Part and parcel of teaching? Secondary school staff's views on supporting student emotional health and well‐being
Authors: Kidger Judi , Gunnell David , Biddle Lucy , Campbell Rona , Donovan Jenny
Published: September 2009

The need for schools to support children and young people's mental and emotional health is increasingly emphasised in policy initiatives, yet the role of teachers in this has been under explored. This paper reports findings from qualitative, semi‐structured interviews with 14 school staff at eight secondary schools in England, examining emotional health and well‐being (EHWB) activities in which they were involved. Three emergent themes are discussed: (1) a strongly held belief that teaching and EHWB are inevitably linked; (2) a perception that many colleagues outside the study sample are reluctant to engage in EHWB work; and (3) a concern that teachers’ own emotional health needs are neglected, leaving them unable or unwilling to consider those of pupils. The findings endorse whole‐school approaches to emotional health, with a focus on teachers’ training and support needs and clearer aims, including consideration of how such work fits with the broader goals of schools.