bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure characterization of high‐purity aluminum processed by dynamic severe plastic deformation
Authors: Dirras Guy , Chauveau Thierry , Abdul‐Latif Akrum , Ramtani Salah , Bui Quang‐Hien
Published: June 2010

Fine‐grained aluminum (700–1000 nm) was processed by dynamic severe plastic deformation of coarse‐grained (3 mm) pure aluminum (99.999 wt.%). The resulting microstructure was characterized by transmission electron microscopy (TEM) and X‐ray profile analyses. It is observed that the grain size determined by TEM departs from measurements made by X‐ray profile analysis. In the latter case, the average crystallite size determined over the global crystallographic or on the deformation‐induced texture components, namely {123} 〈 751 〉, {100} 〈 011〉, and {223} 〈 154 〉, yields similar values (∼225 nm). By contrast, the dislocation density determined on these texture components is about two times higher than the one measured on the global texture. The difference might be related to the specificities of the induced crystallographic texture.
Reflectance anisotropy spectra of CdTe(001) surfaces
Authors: Vázquez‐Nava R. A. , Arzate N. , Mendoza B. S.
Published: June 2010

We present first‐principles calculations of reflectance anisotropy spectra (RAS) of the more common CdTe(001) surface reconstructions: Te‐terminated $(2 \times 1)$ and Cd‐terminated $(2 \times 1)$ and c$(2 \times 2)$. The last two reconstructions with a Cd coverage of half atomic layers. Calculations have been performed by using the density‐functional formalism within the local‐density approximation + scissors corrections. The electron–ion interaction has been modeled by ab initio, relativistic norm‐conserving pseudopotentials. We have also calculated RAS spectra using a semi‐empirical tight binding method (SETB) within a ${\rm sp}^3 {\rm s}^*$ basis. We show RAS of each surface reconstruction and compare our theoretical results with experimental results reported in the literature and we found a good agreement between experimental and theoretical spectra for the $(2 \times 1)$ reconstructions.
Enhanced back and forward scattering in the reflection of light from weakly rough random metal surfaces
Authors: Simonsen Ingve
Published: June 2010

The scattering of light from a weakly rough random silver surface characterized by a double rectangular power spectrum is studied by numerical simulations. This power spectrum can support both the enhanced back and forward scattering phenomena, which for weakly rough surfaces, are both related to the excitation of surface plasmon polaritons. Here we review these phenomena and present new results from a numerical study of the dependence of the diffuse scattering on the amplitudes (γi, i = 1, 2) of the two rectangular portions of the power spectrum. It is found that there exist an optimal range of ratios, γ2/γ1, over which forward scattering peaks can be observed. By just changing the correlations along the interface, while keeping all other parameters like roughness, polarization, and angle of incidence unchanged, the fraction of the incident light that is scattered diffusely can be as large as 16%, while for other parameters as small as 1%. Moreover, a change in the correlation function only, can result in a 3.5 times increase in the amount of light that is absorbed at the weakly rough metal interface (σ = 10 nm).
Synchrotron infrared spectroscopic ellipsometry for characterization of biofunctional surfaces
Authors: Sun Guoguang , Rosu Dana Maria , Zhang Xin , Hovestädt Marc , Pop Simona , Schade Ulrich , Aulich Dennis , Gensch Michael , Ay Bernhard , Holzhütter Hermann‐Georg , Zahn Dietrich R. T. , Esser Norbert , Volkmer Rudolf , Rappich Jörg , Hinrichs Karsten
Published: June 2010

The structural and thickness homogeneity of different biofunctional surfaces after coating an Au substrate was studied by infrared spectroscopic ellipsometry (IRSE). Monolayer coverage was achieved by washing the samples in aqueous solution. A selected cysteine‐modified CHL peptide and an anti‐glutathione S‐transfer (GST) antibody produced a characteristic change in the IR ellipsometric spectra after peptide and antibody adsorption, confirming the biosensing ability of this technique. IR ellipsometric mapping at the synchrotron storage ring BESSY II in Berlin allowed laterally resolved characterization of the protein films. The IR ellipsometric tanΨ and Δ maps revealed that the protein films are inhomogeneous in structure and thickness after adsorption of the peptide and antibody. The absolute thickness of the protein films varied considerably by up to 3 to 7 nm. We also studied cytosine films with different thicknesses (d = 58 nm and 125 nm) and a guanine film (d = 84 nm). For the two cytosine films the synchrotron spectra revealed that the thicker film in particular was rather homogeneous in thickness but inhomogeneous in structure. For the guanine film the shape of vibrational bands in the ellipsometric spectra correlated with anisotropic molecular orientations.
a ‐plane AlN and AlGaN growth on r ‐plane sapphire by MOVPE
Authors: Miyagawa Reina , Miyake Hideto , Hiramatsu Kazumasa
Published: June 2010

The growth of a‐plane (11‐20) AlN and AlGaN on r‐plane (1‐102) sapphire has been investigated with the aim of application to LEDs and LDs in the deep ultra‐violet region. a‐plane AlN and AlGaN were grown on r‐plane sapphire by low‐pressure metalorganic vapor phase epitaxy (LP‐MOVPE). The crystalline quality and surface morphology of a‐plane AlN were optimized at a growth temperature of 1250 °C with the off‐angle of r‐plane sapphire between ‐1° and +1°, and a‐plane AlGaN grown on the AlN layer using ‐0.45°‐off r‐plane sapphire as a substrate exhibited high crystalline quality. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Performance and reliability of ultraviolet‐C pseudomorphic light emitting diodes on bulk AlN substrates
Authors: Grandusky James , Cui Yongjie , Gibb Shawn , Mendrick Mark , Schowalter Leo
Published: June 2010

Low dislocation density, epitaxial layers of AlxGa1–xN are grown pseudomorphically on native AlN substrates prepared from high quality, bulk crystals. In addition to low dislocation density, they are atomically smooth and can be doped n‐type to obtain sheet resistances < 200 Ohms/sq/μm. These layers are used as templates for the growth of high quality multiple quantum well (MQW) structures and ultraviolet (UV) light emitting diodes (LED). The pseudomorphic growth and atomically smooth surfaces are achieved for a full device structure. Previously we have demonstrated the high optical quality of these structures through temperature dependant photoluminescence measurements and X‐ray diffraction. Recently full device structures have been fabricated and packaged. These devices, with emission wavelength between 250 nm and 280 nm show linear increase in output power as a function of current up to 150 mA in thermal equilibrium. Additionally output powers up to 1.3 mW have been achieved at 258 nm at 400 mA drive current. Reliability of the devices has been measured for 1000 hours with expected lifetimes greater than 3000 hours for input currents up to 150 mA (with an average current density of approximately 150 A/cm2). (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Combination of short‐range periodicity and interfacial stress effects on valence band scheme in strained MQW (GaN/AlGaN)n
Authors: Emura Shuichi , Tani Hironobu , Kin Masane , Zhou Yi‐Kai , Hasegawa Shigehiko , Asahi Hajime
Published: June 2010

We observed intense photoluminescence from the GaN well layers of the multi‐quantum well consisting of GaN and Al0.24Ga0.76N with various thicknesses (about 0.8, 1.6, 2.4 nm) of the GaN well layers. The peak position of the photoluminescence largely shifts towards the higher energy and the peak intensity becomes strong enormously with the decreasing of the GaN well‐layer thickness. We qualitatively discuss on the effects of the interfacial stress (strain) and the induced dielectric polarization in addition to the short‐range periodicity to elucidate the observed phenomena instead of the usual explanation based on an internal electric field effect, that seems to be too intuitive and of little physical logic. The band scheme alteration is also discussed with the observed phenomena of the photoluminescence in connection with the above argument. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lateral patterning of GaN polarity using wet etching process
Authors: Fukuhara Yujiro , Katayama Ryuji , Onabe Kentaro
Published: June 2010

A lateral patterning of GaN polarity using wet etching process is demonstrated. The lattice polarity of a GaN film is examined by RHEED, KOH etching, micro‐Raman scattering and Kelvin force microscopy investigations. We have confirmed the high crystal quality of the lattice‐polarity inverted GaN heterostructure fabricated by the all‐wet process. The difference between the surface potentials of the N‐polar and Ga‐polar GaN regions originates from the inversion of the direction of the spontaneous polarization as deduced from the fact that the piezoelectric polarization is negligible compared with the spontaneous polarization. The KOH etching result is consistent with the above mentioned result. This work is the first and direct demonstration for the successful fabrication of the polarity‐inverted GaN heterostructure by an all‐wet process. We suggest the feasibility of the convenient all wet process for the fabrication of the quasi‐phase‐matched waveguides and photonic crystals for efficient nonlinear frequency conversion (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gate‐recessed normally‐off GaN‐on‐ Si HEMT using a new O2‐BCl3 digital etching technique
Authors: Burnham Shawn D. , Boutros Karim , Hashimoto Paul , Butler Colleen , Wong Danny W.S. , Hu Ming , Micovic Miroslav
Published: June 2010

A new, semi‐self‐limiting, digital etch process using separate oxygen (O2) and boron trichloride (BCl3) plasmas to sequentially remove layers of material from AlGaN/GaN high electron mobility transistors (HEMTs) on the order of a few angstroms per cycle is presented. This novel digital or atomic layer etching (ALE) technique was used for the conversion of AlGaN/GaN HEMT devices from depletion mode (normally‐on operation) to enhancement mode (normally‐off operation). For a fixed BCl3 time of 60 sec per cycle, the etch rate per cycle was increased from 1.4 nm/cycle to 2.5 nm/cycle by increasing the O2 time per cycle from zero to 15 seconds, and remained fairly constant with higher O2 time per cycle for a self‐limiting etch process. Two GaN‐on‐Si wafers from the same CVD growth were processed side‐by‐side using the device layout and process steps, except for the depletion‐to‐enhancement conversion step, to compare ALE and fluorine treatment. The ALE‐processed had a peak gm of 250 mS/mm, 67% higher than the fluorine‐treatment process. The ALE process resulted in a threshold voltage variation of +/‐ 150 mV across the 3 inch wafer (σ = 63 mV), which was less than half of that of the fluorine‐treatment wafer. The three‐terminal breakdown voltage of the ALE‐processed wafer exceeded 1100 V, which is the first demonstration of such a high voltage device using GaN‐on‐Si and a gate recess technique, and the drain leakage current was in the μA/mm range at 1100 V. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The study on Schottky contact between Ti and GaSe
Authors: Huang Wen‐Chang , Horng Chia‐Tsung , Chen Yu‐Min , Chen Chien‐Chou
Published: June 2010

A new Schottky contact, Ti/p‐GaSe was presented at this study. It shows an effective barrier height of 1.01 eV with an ideality factor of 2.8 and a reverse leakage current density of 3.8×10‐7 A/cm2 at a reverse voltage of 4 V was measured after rapid thermal annealing at 350 °C for 30 s. The capacitance‐voltage measurement was also used to evaluate the diode characteristics. The annealed diodes also showed linear relationship at the capacitance‐voltage (C‐2‐V) plotting. The formation of TiGaSe2 was observed by X‐ray diffraction analysis after the diode was annealed at 250 °C for 30 s. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transport, magnetic and structural properties of bulk In2‐xFexO3
Authors: Fahed C. , Qadri S. B. , Kim H. , Piqué A. , Miller M. , Mahadik N. A. , Rao M. V. , Osofsky M.
Published: June 2010

Bulk samples of In2‐xFexO3 were synthesized for x ≤ 0.40 in a body‐centered cubic phase. Their structural, transport and magnetic properties were investigated as a function of composition. The lattice parameters of the solid solutions decrease with increasing Fe‐content. The electrical data showed reduced conductivities for higher Fe compositions. The magnetic measurements showed paramagnetic behavior for x values of 0.1 and 0.2, and a small degree of ferromagnetism for x = 0.4. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Room‐temperature ferromagnetism in V‐doped GaN thin films grown by MOCVD
Authors: Souissi M. , Schmerber G. , Derory A. , El Jani B.
Published: June 2010

V‐doped GaN thin films were grown on c‐sapphire substrate by metal organic chemical vapour deposition method (MOCVD). We have used vanadium tetrachloride (VCl4) to intentionally incorporate vanadium (V) during the crystal growth of GaN. X‐ray diffraction measurements revealed no secondary phase in the samples.

Magnetic experiments using superconducting quantum interference device (SQUID) showed clear hysteresis loop in magnetization versus applied field (M –H) curves for V‐doped GaN films. The ferromagnetic behavior was evidenced at 300 K, implying the Curie temperature to be over 300 K. Strong and broad blue‐luminescent band (centered at 2.6 eV) is induced by the V doping in GaN. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
RF‐plasma assisted PLD growth of Zn3N2 thin films
Authors: Ayouchi Rachid , Casteleiro Catarina , Santos Luis , Schwarz Reinhard
Published: June 2010

Polycrystalline Zn3N2 films were prepared on sapphire and quartz substrates by reactive pulsed laser ablation of a metallic zinc target in a nitrogen plasma atmosphere using a frequency‐doubled Nd:YAG laser, assisted by a 13.56 MHz radio‐frequency (RF) plasma. The morphological, structural and optical properties are studied by Scanning Electron Microscopy, X‐ray diffraction, transmittance and ellipsometric spectroscopy. SEM revealed a very smooth and crack‐free film surface. X‐ray diffraction indicates that the Zn3N2 films deposited at 400 °C substrate temperature are cubic in structure with no preferred orientation. The lattice constant has been estimated to be a = 0.97 nm. The absorption coefficient is deduced from the transmission spectra, and its dependence on photon energy is examined to determine the optical band gap. Refractive index and film thickness are deduced from spectroscopic ellipsometry measurements. Zn3N2 is determined to be a n‐type semiconductor with a direct band gap of 3.2 eV. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of SnO2:F thin films deposited by an economic spray pyrolysis technique
Authors: Memarian Nafiseh , Rozati Seyed Mohammad , Elamurugu Elangovan , Fortunato Elvira
Published: June 2010

Fluorine doped tin oxide (FTO) semiconductor thin films were deposited on glass substrates using spray pyrolysis technique and the effect of fluorine (F‐) doping (varying 0‐30 at%) is explored. X‐ray diffraction studies confirmed the tetragonal structure with polycrystalline nature. The crystallinity of undoped films is enhanced with the increase in F‐doping. The films doped with 25 at% F show a strong orientation along (101) plane. The grain size of the undoped films (214 nm) is increased with the increase in F‐doping level to reach a maximum of 415 nm (25 at% F). A minimum sheet resistance of ∼5.4 Ω/□ obtained for the 30 at% F doped films is among the lowest reported values. The average visible transmittance (400‐700 nm) of the undoped films (61.4%) is increased with the increasing F‐doping to reach a maximum of 74.5% (25 at%. F). The films doped with 25 at.% F showed high value of figure of merit (4.55 × 10‐3 Ω‐1). The obtained results authenticate the influence of F‐doping on the properties of the deposited films. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Zn1‐xMgxO thin films deposited by spray pyrolysis
Authors: Sahal M. , Marí B. , Mollar M. , Manjón F. J.
Published: June 2010

This work reports on an analysis of the chemical composition, structural, and optical properties of Mg‐doped zinc oxide (ZMO) thin films with Mg concentration up to 54 at.% and prepared by the spray pyrolysis technique from acetate precursors. Chemical analysis show that the [Mg]/[Zn] ratio incorporated into the films is higher than that present in the starting solution. X‐ray diffraction, Raman scattering, and transmission measurements show that all samples exhibit a single phase wurtzite structure with a transmittance above 70% in the visible range. Increasing Mg content leads to an increase of the band gap energy from 3.23 in pure ZnO to 3.57 eV in films with 54 at% of Mg content. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Micro power generation of PMN‐PZT triple morph cantilever for electric harvesting devices
Authors: Kim Insung , Joo Hyeonkyu , Jeong Soonjong , Kim Minsoo , Song Jaesung
Published: June 2010

Piezoelectric cantilever was manufactured using the PMN‐PZT thick film for electric harvesting device. In order to find the better properties, the piezoelectric cantilever was manufactured by two forms (bi‐morph and triple‐morph). The generation characteristics were investigated according to the variations of frequency, load resistance and mass weight. The piezoelectric cantilever output voltage increased according to the increase of load resistance and the output power quality was also investigated by changing the load resistance, mass weight and frequency. The bi‐morph piezoelectric cantilever output power which resulted from the conditions of 33 kΩ, 0.25 g, 197 Hz was 230 μW at 2.75VRMS. And then, Average micro power from triple‐morph piezoelectric cantilever was 432 μW, 6.57 VRMS at 154 Hz. This paper presented the possibility of electric harvesting devices with using PMN‐PZT triple‐morph cantilever for remote control and sensor node. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Eulityte glasses – synthesis and characterization
Authors: Berbecaru Ciceron , Alexandru Horia V. , Polosan Silviu
Published: June 2010

Oxides glasses are suitable for electronic and optoelectronic applications (band gap higher than 3 eV). Eulytite glasses were obtained from Bi4GeO14 sintered powder or mixture oxides powders Bi2O3–GeO2. The powders rapidly heated and melted at 1050 °C for 5 ÷ 10 min was poured on the graphite plates under the glass transition temperature. Structural SEM, XRD and EDX investigations were performed at room temperatures. The frequency dependence of the permittivity and loss (45 Hz ÷ 5 MHz) was investigated on a large temperature range between –140 and +375 °C. The permittivity and loss increase with the temperatures increase and decrease with the frequency increase. An activation energy of 0.88 kcal/mol, comparable to the thermal energy RT = 0.65 kcal/mol, was found for cluster formation on 150 ÷ 200 °C temperature range. The jump of permittivity on the range 275 ÷ 325 °C suggest an incipient glass transition at lower temperatures than 400 °C, as usually is accepted. The permittivity increase, correlated with the dipolar polarization was noticed at higher temperatures. The decrease of permittivity and loss in 10 ÷ 100 kHz frequency range, at the mentioned temperatures, supports this assertion. The estimated relaxation times suggest the big clusters formation. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient evaluation of the accuracy of molecular quantum dynamics on an approximate analytical or interpolated ab initio potential energy surface
Authors: Zimmermann Tomáš , Ruppen Julien , Li Baiqing , Vaníček Jiří
Published: June 2010

Ab initio electronic structure methods have reached a satisfactory accuracy for the calculation of static properties, but remain too expensive for quantum dynamical calculations. Recently, an efficient semiclassical method was proposed to evaluate the accuracy of quantum dynamics on an approximate potential without having to perform the expensive quantum dynamics on the accurate potential. Here, this method is applied for the first time to evaluate the accuracy of quantum dynamics on an approximate analytical or interpolated potential in comparison to the quantum dynamics on an accurate potential obtained by an ab initio electronic structure method. Specifically, the vibrational dynamics of H2 on a Morse potential is compared with that on the full CI potential, and the photodissociation dynamics of CO2 on a LEPS potential with that on the excited 1Π surface computed at the EOM‐CCSD/aug‐cc‐pVDZ level of theory. Finally, the effect of discretization of a potential energy surface on the quantum dynamics is evaluated. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem 110:2426–2435, 2010
Bmi1 Distinguishes Immature Retinal Progenitor/Stem Cells from the Main Progenitor Cell Population and Is Required for Normal Retinal Development
Authors: Chatoo Wassim , Abdouh Mohamed , Duparc Robert-Hugues , Bernier Gilbert
Published: June 2010

The developing mammalian retina is generated by the proliferation and differentiation of multipotent retinal progenitor cells (RPCs) giving rise to neuronal and glial lineages. Whether an immature progenitor/stem cell subpopulation is present in the developing mammalian retina remains undefined. Deficiency in the polycomb group gene Bmi1 results in reduced proliferation and postnatal depletion of neural and hematopoietic stem cells. Here, we show that Bmi1 is required for the self-renewal of most immature RPCs and for postnatal retinal development. In the embryo, Bmi1 is highly enriched in a rare stage-specific embryonic antigen-1-positive RPC subpopulation expressing the stem cell markers Sox2, Lhx2, and Musashi. Gain-of-function experiments revealed that Bmi1 overexpression could convert RPCs having limited proliferation capacity into RPCs showing extensive proliferation and multiple differentiation capacities over time. At all developmental stages analyzed using the neurosphere assay, Bmi1 deficiency resulted in reduced proliferation and self-renewal of most immature RPCs. Reduced RPCs proliferation was also observed in the peripheral retina of Bmi1−/− fetus and newborn mice. The biological impact of these developmental anomalies was revealed by the reduced retinal diameter of Bmi1-deficient pups. P19Arf and p16Ink4a were upregulated in vivo and in vitro and coinactivation of p53, which lies downstream of p19Arf, partially restored Bmi1-deficient RPCs self-renewal phenotype. Bmi1 thus distinguishes immature RPCs from the main RPC population and is required for normal retinal development.
Abnormal brain microstructure and metabolism in small‐for‐gestational‐age term fetuses with normal umbilical artery Doppler
Authors: Sanz‐Cortés M. , Figueras F. , Bargalló N. , Padilla N. , Amat‐Roldan I. , Gratacós E.
Published: June 2010

Objectives

To assess microstructural and metabolic brain differences between small‐for‐gestational age (SGA) and appropriate‐for‐gestational age (AGA) fetuses at 37 weeks' gestation by magnetic resonance imaging (MRI) spectroscopy and diffusion weighted imaging.

Methods

Eight SGA and five matched AGA singleton fetuses, all with normal umbilical artery Doppler, were evaluated using MRI at 37 weeks to measure markers of brain microstructure and metabolism. The metabolic spectrum of N‐acetyl‐aspartate/choline, choline/creatine, inositol/choline and creatine/choline ratios in the left frontal lobe and the apparent diffusion coefficient from the right and left basal ganglia and frontal and occipital lobes, pyramidal tract and corpus callosum were analyzed and compared.

Results

As compared with controls, SGA fetuses showed a significant increase in inositol/choline ratio (SGA, 0.57 vs. AGA, 0.25; P = 0.04) and significantly higher ADC values in the pyramidal tract (SGA, 119.87 × 10−5 mm2/s vs. AGA, 105.11 × 10−5 mm2/s; P = 0.04).

Conclusions

SGA fetuses with normal umbilical artery Doppler present microstructural and metabolic brain changes, suggesting the existence of an abnormal in‐utero brain development in fetuses with this condition. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Narrativity and non‐Narrativity
Authors: Strawson Galen
Published: June 2010

I argue against two popular claims. The first is a descriptive, empirical claim about the nature of ordinary human experience which I call the psychological Narrativity thesis (PNT). According to PNT, ‘each of us constructs and lives a “narrative” … this narrative is us, our identities’ (Sacks O. The Man Who Mistook His Wife for a Hat. London: Duckworth; 1985, 110). The second is a normative, ethical claim which I call the ethical Narrativity thesis (ENT). According to ENT, we ought to live our lives narratively, or as a story: a ‘basic condition of making sense of ourselves is that we grasp our lives in a narrative’ and have an understanding of our lives ‘as an unfolding story’ (Taylor C. Sources of the Self. Cambridge: Cambridge University Press; 1989, 47–52). On this view a person ‘creates his identity (only) by forming an autobiographical narrative—a story of his life’, and must be in possession of a full and ‘explicit narrative (of his life) to develop fully as a person’ (Schechtman M. The Constitution of Selves. Ithaca, NY: Cornell University Press; 1996, 93. WIREs Cogn Sci 2010 1 775–780

This article is categorized under:

Philosophy > Metaphysics
A Recess Evaluation with the Players: Taking Steps Toward Participatory Action Research
Authors: Ren Julie Yunyi , Langhout Regina Day
Published: June 2010

This playground study conceptualizes recess as a time and space that belongs to students; their inclusion in this evaluation is a notable difference from other recess/playground research. The goal was to help elementary school students make the changes they felt were needed on their playground. After conducting structured observations and student and recess aide focus groups, a report was presented to all stakeholders, and recess changes were made. We seek to show how the process of being inclusive during the evaluation was not only valuable for determining problem definition and potential interventions, but was also necessary to determine the best methods for solutions, move toward second‐order change, and to create a space to facilitate children's participation and empowerment.
Folate and cancer: how DNA damage, repair and methylation impact on colon carcinogenesis
Authors: Duthie Susan J.
Published: June 2010

Inappropriate diet may contribute to one third of cancer deaths. Folates, a group of water‐soluble B vitamins present in high concentrations in green, leafy vegetables, maintain DNA stability through their ability to donate one‐carbon units for cellular metabolism. Folate deficiency has been implicated in the development of several cancers, including cancer of the colorectum, breast, ovary, pancreas, brain, lung and cervix. Generally, data from the majority of human studies suggest that people who habitually consume the highest level of folate, or with the highest blood folate concentrations, have a significantly reduced risk of developing colon polyps or cancer. However, an entirely protective role for folate against carcinogenesis has been questioned, and recent data indicate that an excessive intake of synthetic folic acid (from high‐dose supplements or fortified foods) may increase human cancers by accelerating growth of precancerous lesions. Nonetheless, on balance, evidence from the majority of human studies indicates that dietary folate is genoprotective against colon cancer. Suboptimal folate status in humans is widespread. Folate maintains genomic stability by regulating DNA biosynthesis, repair and methylation. Folate deficiency induces and accelerates carcinogenesis by perturbing each of these processes. This review presents recent evidence describing how these mechanisms act, and interact, to modify colon cancer risk.
Orphanet – das europäische Portal für seltene Krankheiten
Authors: Rommel K. , Nyoungui E. , Dierking A. , Langenbeck U. , Schmidtke J. , Stuhrmann M.
Published: June 2010

Orphanet ist eine relationale Datenbank über seltene Krankheiten und Arzneimittel für seltene Krankheiten (Orphan Drugs). Die internetbasierte Informationsplattform wurde im Jahr 1997 durch das französische Gesundheitsministerium und INSERM (Institut National de la Santé et de la Recherche Médicale) ins Leben gerufen. Seit dem Jahr 2000 wird Orphanet als europäisches Projekt fortgeführt. Das Konzept der Datenbank basiert auf der Idee, allen beteiligten Interessengruppen Informationen über seltene Krankheiten in Form eines Katalogs von Fachdienstleistungen bereitzustellen. Dieses Angebotsverzeichnis umfasst Informationen über Spezialsprechstunden und Kliniken, Diagnostikangebote, Forschungsprojekte, klinische Studien, Netzwerke, Register und Selbsthilfegruppen aus derzeit 38 Ländern. Die erfassten Leistungen sind unmittelbar mit dem Verzeichnis der seltenen Krankheiten assoziiert, darüber hinaus ist eine umfangreiche Enzyklopädie verfügbar. Alle Informationen sind kostenfrei und in 5 Sprachen über die Website http://www.orpha.net abrufbar.
Internal jugular vein collapsibility index associated with hypovolemia in the intensive care unit patients
Authors: Killu Keith , Coba Victor , Huang Yung , Andrezejewski Tanja , Dulchavsky Scott
Published: June 2010

Objective

To evaluate the correlation between the internal jugular vein (IJV) collapsibility index and hypovolemia in intensive care unit (ICU) patients, using point of care ultrasound imaging.

Methods

A prospective observational study was conducted in an urban tertiary care teaching hospital, in the surgical ICU. Intensivist point-of-care sonographers performed IJV ultrasound on 31 ICU patients who were diagnosed to be hypovolemic or euvolemic by their treating ICU physicians.

Results

Hypovolemic ICU patients (16 of 31) were 50% male and 75% white with a mean age of 63 (±19) years. The variables measured between the hypovolemic and euvolemic ICU patients were the mean arterial pressure, heart rate, respiratory rate, central venous pressure (CVP). Their correlation with hypovolemia was significant (p < 0.05). The ROC curve analysis found the IJV collapsibility index ≥39% correlated best with hypovolemic ICU patient with a sensitivity of 87.5% and specificity 100%. The area under ROC curve for IJV collapsibility index was 0.938, with no significant difference to CVP with the area under ROC curve of 0.87 (p = 0.467).

Conclusion

IJV collapsibility index can be identified by intensivist point-of-care sonographers in the hypovolemic and euvolemic ICU patients. The presence of IJV collapsibility index greater than 39% may be associated with hypovolemia in ICU patients.
EvolTrack: improving design evolution awareness in software development
Authors: de Cepêda Rafael da Silva Viterbo , Magdaleno Andréa Magalhães , Murta Leonardo Gresta Paulino , Werner Cláudia Maria Lima
Published: June 2010

Software differs from most manufactured products because it is intangible. This characteristic makes it difficult to detect, control, and understand how it evolves. This paper presents an approach based on software visualization that can detect and externalize design evolution made in a software project during its initial development or at any further phase. By using this approach, a developer can be aware of the current state of the software as a whole and can additionally verify if the current design, also called emerging design, is evolving according to the team expectations and leader guidance, preventing problems caused by misunderstandings of the expected software solution. The approach was evaluated with free/open source software (FOSS) projects. The results indicate that the approach behaves as expected when applied to real software development projects, with minor performance bottlenecks.
Effects of transdermal estradiol gel and oral tibolone on health‐related quality of life after surgical menopause
Authors: Bhattacharya Sudhindra M. , Jha Ayan
Published: June 2010

Objective

To study the effects of 6 months of treatment with transdermal estradiol gel versus oral tibolone on health‐related quality of life (HRQOL) after surgical menopause.

Methods

In a randomized single‐blind trial, Indian women received either oral tibolone tablets (2.5 mg) or transdermal estradiol gel (0.06%) daily. Each woman scored herself on the Menopause Rating Scale (MRS) II at the beginning of the study and after 6 months. Independent t tests were used to determine the significance of changes in HRQOL.

Results

In total, 31 (81.6%) women who received estradiol gel and 38 (100.0%) women who received tibolone completed treatment. Intent‐to‐treat analysis showed that, after 6 months of treatment, the total MRS score was significantly reduced in the tibolone group compared with the transdermal estradiol gel group (− 9.5 ± 5.1 versus − 4.9 ± 5.7; 95% confidence interval, 2.0–7.0; P < 0.01). Significant improvements were also noted in the tibolone group in terms of somatovegetative (P = 0.04) and psychologic (P < 0.01) domains.

Conclusion

Oral tibolone treatment was more effective than transdermal estradiol gel at improving HRQOL in Indian women with surgical menopause.
Visual screening for early detection of cervical neoplasia in Angola
Authors: Muwonge Richard , Manuel Miraldina da Ganda , Filipe Antonio P. , Dumas Joaquim Bernardo , Frank Margarida Ranque , Sankaranarayanan Rengaswamy
Published: June 2010

Objective

A cross‐sectional study in Angola to evaluate the feasibility of cervical screening using visual inspection with acetic acid (VIA) or Lugol's iodine (VILI) to detect and treat cervical intraepithelial neoplasia (CIN).

Methods

All 8851 women screened by trained nurses received colposcopy and/or colposcopically‐directed biopsies. The final disease status was based on histopathology or colposcopy when no or inadequate biopsies were done. The sensitivity, specificity, and predictive values of tests to detect CIN 2–3 were calculated.

Results

VIA was positive in 6.6% and VILI in 32.0% of the women. The positivity rates increased with time only for VILI. CIN 2–3 was diagnosed in 75 women and invasive cancer in 57. The sensitivity and specificity was 70.7% (95% CI, 59.0%–80.6%) and 94.5% (95% CI, 94.0%–95.0%) respectively for VIA, and 88.0% (95% CI, 78.4%–94.4%) and 68.9% (95% CI, 67.9%–69.9%) for VILI. Ninety percent of women detected with CIN received treatment. Treatment was given on the same day as screening to one‐third of the 374 women treated with cryotherapy/LEEP. No major complications or adverse effects were associated with treatment.

Conclusion

It was feasible to screen with both visual tests and treat women with CIN in Angola. VILI was less specific than VIA, implying subjectivity in interpreting test results.
Gastric Glomus Tumor: A Case Report and Review of the Literature
Authors: Huang Chuang‐Chi , Yu Fang‐Jung , Jan Chang‐Ming , Yang Sheau‐Fang , Kuo Yu‐Ting , Hsieh Jan‐Sing , Wang Jaw‐Yuan
Published: June 2010

Glomus tumors are usually thought of as benign tumors although some malignant cases have been reported. These tumors arise from the glomus body and are commonly observed in the dermis or subcutis, but rarely in visceral organs. Here, we report a 37‐year‐old female who initially presented with epigastric discomfort. The preoperative diagnosis was a gastrointestinal stromal tumor. A minilaparotomy was done with an incision length of 4 cm followed by wedge resection. The final pathologic diagnosis was a gastric glomus tumor. We have reviewed the only five cases of gastric glomus tumors that have been reported to date in Taiwan, including the present case, and compare these cases with those reported in other countries. The age of onset ranged from 35 to 69 years (median, 41 years) with female dominance (4 females and 1 male). Two of the five cases presented with gastrointestinal bleeding with an ulcerative tumor, and the others only had epigastric discomfort. The tumors were located around the prepyloric antrum of the stomach. No definite diagnosis was reached before surgery in any of the five cases, and all of the tumors were considered likely to be benign lesions. Clinicians who treat such patients should be aware of this problem because of the difficulty in accurate preoperative diagnosis.
Alexithymia Associated With Bilateral Globus Pallidus Lesions After Carbon Monoxide Poisoning
Authors: Huang Mei‐Feng , Yeh Yi‐Chun , Tsang Hin‐Yeung , Chen Cheng‐Sheng
Published: June 2010

Alexithymia refers to a person's inability to identify and describe feelings. We present a patient who developed alexithymia after carbon monoxide poisoning following a suicide attempt by burning charcoal in an enclosed space. Brain computed tomography revealed bilateral globus pallidus hypoxic lesions. Because of the time frame and the presence of brain structural lesions, the alexithymia in this patient was thought to be caused by bilateral globus pallidus hypoxic lesions resulting from carbon monoxide poisoning. The alexithymia in this patient did not respond to a variety of psychotropic drugs, including sertraline, venalfaxine, bupropion or methylphenidate. We suggest that alexithymia, which was associated with brain hypoxic lesions in this case, is resistant to treatment.
Why Aren't Women Sticking With Science in Taiwan?
Authors: Cheng Ling‐Fang
Published: June 2010

This paper explores the factors that contribute to the “leaky pipeline” in science, technology and medicine in Taiwan. The term “leaky pipeline” refers to the steady attrition of women throughout their careers in science, technology and medicine—fields in which men constitute the majority. As a result of this attrition, women are under‐represented in the top positions. This phenomenon has been well studied in the United States, and based on the available data in the Chinese and English‐language literature, this paper focuses on: (1) the social–cultural factors that keep young women away from science and medicine; (2) the difficulties faced by woman scientists when trying to balance work and family responsibilities; and (3) the impact of the pervasive masculine culture on training and promotion in career development. Conclusions include suggestions for improvements for equality between the sexes in science education, family responsive policies, and institutional reform.
Reynolds stress and eddy viscosity in direct numerical simulations of sheared two-dimensional turbulence
Authors: CUMMINS PATRICK F. , HOLLOWAY GREG
Published: June 2010

The Reynolds stress associated with the adjustment of two-dimensional isotropic eddies subject to a large-scale shear flow is examined in a series of initial-value calculations in a periodic channel. Several stages in the temporal evolution of the stress can be identified. Initially, there is a brief period associated with quasi-passive straining of the eddy field in which the net Reynolds stress and the associated eddy viscosity remain essentially zero. In spectral space this is characterized by mutual cancellation of contributions to the Reynolds stress at high and low eddy wavenumbers. Subsequently, eddy–eddy interactions produce a tendency to restore isotropy at higher eddy wavenumbers, leading to an overall positive eddy viscosity associated with the dominant contribution to the Reynolds stress at low eddy wavenumbers. These results are consistent with theoretical predictions of positive eddy viscosity for initially isotropic homogeneous two-dimensional turbulence. Due to the inverse cascade, the accumulation with time of energy at the scale of the channel produces a competing tendency to negative eddy viscosity associated with linear shearing of the disturbances. This finite-domain effect may become dominant if the nonlinearity of the eddy field is relatively weak.
The rise and fall of turbulent fountains: a new model for improved quantitative predictions
Authors: CARAZZO G. , KAMINSKI E. , TAIT S.
Published: June 2010

Turbulent fountains are of major interest for many natural phenomena and industrial applications, and can be considered as one of the canonical examples of turbulent flows. They have been the object of extensive experimental and theoretical studies that yielded scaling laws describing the behaviour of the fountains as a function of source conditions (namely their Reynolds and Froude numbers). However, although such scaling laws provide a clear understanding of the basic dynamics of the turbulent fountains, they usually rely on more or lessad hocdimensionless proportionality constants that are scarcely tested against theoretical predictions. In this paper, we use a systematic comparison between the initial and steady-state heights of a turbulent fountain predicted by classical top-hat models and those obtained in experiments. This shows scaling agreement between predictions and observations, but systematic discrepancies regarding the proportionality constant. For the initial rise of turbulent fountains, we show that quantitative agreement between top-hat models and experiments can be achieved by taking into account two factors: (i) the reduction of entrainment by negative buoyancy (as quantified by the Froude number), and (ii) the fact that turbulence is not fully developed at the source at intermediate Reynolds number. For the steady-state rise of turbulent fountains, a new model (‘confined top-hat’) is developed to take into account the coupling between the up-flow and the down-flow in the steady-state fountain. The model introduces three parameters, calculated from integrals of experimental profiles, that highlight the dynamics of turbulent entrainment between the up-flow and the down-flow, as well as the change of buoyancy flux with height in the up-flow. The confined top-hat model for turbulent fountains achieves good agreement between theoretical predictions and experimental results. In particular, it predicts a systematic increase of the ratio between the initial and steady-state heights of turbulent fountains as a function of their source Froude number, an observation that was not handled properly in previous models.
Sexual abuse and psychiatric disorder in England: results from the 2007 Adult Psychiatric Morbidity Survey
Authors: Jonas S. , Bebbington P. , McManus S. , Meltzer H. , Jenkins R. , Kuipers E. , Cooper C. , King M. , Brugha T.
Published: June 2010

Background

Evidence is accumulating that child sexual abuse (CSA) is associated with many psychiatric disorders in adulthood. This paper uses the detailed information available from the 2007 Adult Psychiatric Morbidity Survey of England (APMS 2007) to quantify links between CSA and a range of psychiatric conditions.

Method

The prevalence of psychiatric disorder was established in a random sample of the English household population (n=7403), which also provided sociodemographic and experiential information.

Results

We analyzed six types of common mental disorder, alcohol abuse and drug abuse, and people who screened positively for post-traumatic stress disorder (PTSD) and eating disorders. All were strongly and highly significantly associated with CSA, particularly if non-consensual sexual intercourse was involved, for which odds ratios (ORs) ranged from 3.7 to 12.1. These disorders were also related to adult sexual abuse (ASA), although the likelihood of reverse causality is then increased. Revictimization in adulthood was common, and increased the association of CSA with disorder. For several disorders, the relative odds were higher in females but formal tests for moderation by gender were significant only for common mental disorders and only in relation to non-consensual sexual intercourse. The population attributable fraction (PAF) was higher in females in all cases.

Conclusions

The detailed and high-quality data in APMS 2007 provided important confirmation both of the strength of association of CSA with psychiatric disorder and of its relative non-specificity. Our results have major implications at the public health level and the individual level, in particular the need for better recognition and treatment of the sequelae of CSA.
Hell and character
Authors: CORABI JOSEPH
Published: June 2010

The view that consignment to hell is a matter of having a fixed vicious character of a certain sort – rather than a matter of paying a retributive penalty for sin – is quite popular among philosophical theologians today. However, if proponents of this view wish to maintain that some individuals wind up consigned to hell, and if they embrace a number of independently plausible assumptions, they will be forced toward unreasonable claims about character development and its relationship to consignment to hell. In this paper, I describe the difficulties for these philosophical theologians.
From Jena to Copenhagen: Kierkegaard's relations to German idealism and the critique of autonomy inThe Sickness Unto Death
Authors: LONCAR SAMUEL
Published: June 2010

This article seeks to demonstrate the influence of J. G. Fichte's philosophy on Søren Kierkegaard's theory of the self as he develops it inThe Sickness unto Deathand to interpret his theory of the self as a religious critique of autonomy. Following Michelle Kosch, it argues that Kierkegaard's theory of the self was developed in part as a critique of idealist conceptions of agency. Moreover, Kierkegaard's view of agency provides a powerful way of understanding human freedom and finitude that has implications for contemporary debates about autonomy, normativity, and agency.
From hope to crisis and back again? A critical history of the global CBNRM narrative
Authors: DRESSLER WOLFRAM , BÜSCHER BRAM , SCHOON MICHAEL , BROCKINGTON DAN , HAYES TANYA , KULL CHRISTIAN A. , MCCARTHY JAMES , SHRESTHA KRISHNA
Published: June 2010

Community-based natural resource management (CBNRM) has been on the ascendancy for several decades and plays a leading role in conservation strategies worldwide. Arriving out of a desire to rectify the human costs associated with coercive conservation, CBNRM sought to return the stewardship of biodiversity and natural resources to local communities through participation, empowerment and decentralization. Today, however, scholars and practitioners suggest that CBNRM is experiencing a crisis of identity and purpose, with even the most positive examples experiencing only fleeting success due to major deficiencies. Six case studies from around the world offer a history of how and why the global CBNRM narrative has unfolded over time and space. While CBNRM emerged with promise and hope, it often ended in less than ideal outcomes when institutionalized and reconfigured in design and practice. Nevertheless, despite the current crisis, there is scope for refocusing on the original ideals of CBNRM: ensuring social justice, material well-being and environmental integrity.
Imitation and Shared Intentionality in the Acheulean
Authors: Shipton Ceri
Published: June 2010

Imitation and shared intentionality are traits essential to the socio-cultural adaptation of Homo sapiens. Non-human apes display some capacity for imitation and shared intentionality, but are deficient in comparison to Homo sapiens. The Acheulean archaeological record provides evidence that imitation and shared intentionality were part of the behavioural repertoire of the hominins manufacturing that industry. The palaeoneurological record suggests some early Homo specimens possessed the neural architecture associated with modern human imitation. From this evidence it is suggested that a propensity for imitation and shared intentionality evolved soon after 2 million years ago.
WEALTH INEQUALITY AND OPTIMAL MONETARY POLICY
Authors: Hiraguchi Ryoji
Published: June 2010

We study the money-in-the-utility-function model in which agents are heterogeneous in their initial wealth. We show that the Friedman rule is not optimal even if the government uses nonlinear income taxation for redistribution. A positive nominal interest rate raises social welfare because it relaxes the incentive compatibility constraint for highly endowed agents. Although the setup is close to that of da Costa and Werning [Journal of Political Economy (2008) 116, 82–112], who investigate skill heterogeneity, the role of the nominal interest rate in this paper here differs from the one in their model.