bluuebunny/crossref_metadata_2025_split huggingface dataset:
InGaN‐based light‐emitting diodes grown on grooved sapphire substrates
Authors: Wang Wei‐Kai , Wuu Don‐Sing , Lin Shu‐Hei , Huang Shih‐Yung , Horng Ray‐Hua 
Published: May 2006

AbstractWe investigate the microstructure and electrical properties of the InGaN‐based light‐emitting diodes (LEDs) fabricated onto patterned sapphire substrates (PSSs) with parallel grooves. The PSS with parallel grooves (ridge: 3 μm; trench: 2 μm) along the (11‐20) direction were etched using an inductively‐coupled‐plasma etcher with different etching depths. It was found that the threading dislocation density in the GaN epilayer can be effectively reduced by the present PSS technique as indicated from the transmission‐electron‐microscopy result. For a typical lamp‐form PSS LED operating at a forward current of 20 mA, the output power and external quantum efficiency were measured to be 7.1 mW and 10.1%, respectively. The achieved improvement of the output power is not only due to the improvement of the internal quantum efficiency upon decreasing the dislocation density, but also due to the enhancement of the extraction efficiency using the PSS. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman scattering from In0.2Ga0.8N/GaN superlattices
Authors: Kisoda Kenji , Hirakura Kohji , Harima Hiroshi 
Published: May 2006

AbstractWe have performed Raman scattering experiments on high quality In0.2Ga0.8N/GaN superlattices(SLs). The A1 LO phonon mode from the In0.2Ga0.8N layer was observed in the Mg doped SL. This was attributable to manifestation of a resonance enhancement via acceptor levels formed by magnesium doping. The peak frequency of the A1 LO mode shifted to high frequency side with the excitation energy. The frequency shift suggested that the composition of indium was fluctuated along the growth direction in the InGaN layer. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Broadband spectrally dynamic solid state illumination source
Authors: Nicol David B. , Asghar Ali , Gupta Shalini , Kang Hun , Pan Ming , Strassburg Martin , Summers Chris , Ferguson Ian T. 
Published: May 2006

AbstractSolid state lighting has done well recently in niche markets such as signage and displays, however, no available SSL technologies incorporate all the necessary attributes for general illumination. Development of a novel solid state general illumination source is discussed here. Two LEDs emitting at two distinct wavelengths can be monolithically grown and used to excite two or more phosphors with varied excitation spectra. The combined phosphorescence spectrum can then be controlled by adjusting the relative intensities of the two LED emissions. Preliminary phosphor analysis shows such a scheme to be viable for use in a spectrally dynamic broadband general illumination source. A tunnel junction is envisioned as a means of current spreading in a buried layer for three terminal operation. However, tunnel junction properties in GaN based materials are not well understood, and require further optimization to be practical devices. Preliminary results on GaN tunnel junctions are presented here as well. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Local structural characterization of epitaxial a ‐plane InGaN/GaN thin films by transmission electron microscopy
Authors: Yamazaki T. , Kusakabe K. , Nakanishi N. , Ohkawa K. , Hashimoto I. 
Published: May 2006

AbstractStructural analysis of the submicron area of an InGaN thin film was conducted using transmission electron microscopy. By obtaining the selected area diffraction patterns of c ‐plane InGaN/GaN and a ‐plane InGaN/GaN films, the local lattice parameters were measured. Coherent growths were checked at the respective samples for different growth orientations, and the In concentration of the InGaN layer was also measured. Furthermore, there is a slight tilt in the growth direction between the GaN and InGaN layers in the a ‐plane InGaN/GaN film. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of the Nile Red spectra by semi‐empirical calculations and spectrophotometric measurements
Authors: Dias Lauro C. , Custodio Rogério , Pessine Francisco B. T. 
Published: May 2006

AbstractThe spectroscopic behavior of Nile Red (NR) in solutions was investigated by spectrophotometric measurements and was calculated with the semi‐empirical intermediate neglect of differential overlap for spectroscopy (INDO/S) method. Two parametrizations implemented, respectively, by Pople and by Da Motta and Zerner, were employed; the solvent effects were simulated according to the dielectric continuum model [self‐consistent reaction field (SCRF)], as well as with the explicit inclusion of solvent molecules. The calculations simulated reasonably well the experimental spectra and the intense solvatochromism of NR because the dipole moments were calculated to be higher in the first excited state than in the ground state. In addition, INDO/S calculations were carried out for partially optimized twisted conformers, whose electron donor moiety was orthogonal to the aromatic acceptor one and charge transfer was observed for excited states known as twisted intramolecular charge‐transfer (TICT) states. In polar media, INDO/S+SCRF calculations drastically stabilized the TICT state, reducing its energy down to the first excited state. Despite this intense solute–solvent stabilization, it is still less stable than the first excited state of the nontwisted, fully optimized conformer, and the limitations of the semi‐empirical methods could not predict its role, if any, on the spectroscopic behavior of NR, except for the fact that the solvatochromism was explained independent of its presence. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Singlet–triplet gaps and insertion reactions of aminocyanocarbenes: A computational study of hydrogen cyanide covalent dimers
Authors: Freeman Fillmore , Gomarooni Mahshid 
Published: May 2006

AbstractSinglet–triplet gaps (S–T, ΔEST), structural parameters, intramolecular CH insertion reactions, intramolecular NH insertion reactions, intermolecular CH insertion reactions, and intramolecular 1,2‐rearrangements of aminocyanocarbenes (NCCNX2, X = H, CH3, CF3) have been studied using restricted and unrestricted CCD, CCSD, QCISD, B3LYP, and MP2 methods with the 6‐31G(d), 6‐311+G(d,p), cc‐pVDZ, and cc‐pVTZ basis sets. HCNH2, NCCNH2, NCCN(CH3)2, and NCCN(CF3)2 have singlet ground states. The ΔEST values for aminocyanocarbene, N,N‐(dimethylamino)cyanocarbene, and N,N‐(ditrifluoromethylamino)cyanocarbene are 29.34, 32.75, and 19.48 kcal/mol, respectively. Aminocyanocarbene, a hydrogen cyanide covalent dimer, is predicted to have higher energy than the dimer (Z)‐C‐cyanomethanimine which is lower in energy than the isomeric (E)‐C‐cyanomethanimine and N‐cyanomethanimine. The three‐centered transition state connecting singlet aminocyanocarbene with (Z)‐C‐cyanomethanimine is 55.7 kcal/mol higher in energy than the carbene and the transition state connecting the E and Z isomers of C‐cyanomethanimine is 29.54 kcal/mol higher in energy than the Z isomer. CCSD/cc‐pVDZ predicted the barrier for the intermolecular insertion of singlet aminocyanocarbene into a CH bond of methane to be 35.40 kcal/mol. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Orbital interactions and charge redistribution in weak hydrogen bonds: Watson–Crick GC mimic involving CH proton donor and F proton acceptor groups
Authors: Guerra Célia Fonseca , Baerends Evert Jan , Bickelhaupt F. Matthias 
Published: May 2006

AbstractThe discovery by Kool and coworkers that 2,4‐difluorotoluene (F) mimics thymine (T) in DNA replication has led to controversy regarding the question of whether this mimic has the capability of forming hydrogen bonds with adenine (A). Recently, we have provided evidence for an important role of both hydrogen bonding and steric effects in the replication of DNA. In the present work, we extend our study to mimics (GFC′N′and CN′NF) of the bases guanine (G) and cytosine (C). We address not only the question of the strengths of the hydrogen bonds in GFC′N′CN′NFas compared with those in GC but we focus in particular on the nature of these interactions. Thus, we have analyzed GFC′N′CN′NFand GC at the BP86/TZ2P level of density functional theory (DFT). In line with previous experience, this approach is shown to achieve close agreement with the available data from ab initio computations and experiment: the complexation energy of GFC′N′CN′NF(‐4.1 kcal/mol) is confirmed to be much weaker indeed than that of GC (‐26.1 kcal/mol). Interestingly, the weak hydrogen bonds in GFC′N′CN′NFstill poses a significant orbital interaction component that resembles the situation for the more strongly bound GC, as follows from (1) an analysis of the orbital electronic structure of GFC′N′CN′NFand GC, (2) a quantitative decomposition of the GFC′N′CN′NFand GC bond energies, as well as (3) a quantitative decomposition of the charge redistribution associated with the GFC′N′ CN′NFand GC interactions based on the Voronoi deformation density (VDD) method. The VDD method allows us to decompose the charge redistribution ΔQper atom into a component associated with the Pauli repulsive orbital interactions and a component associated with the bonding orbital interactions: ΔQ= ΔQPauli+ ΔQoi. Implications of our findings for the mechanism of DNA replication are discussed. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Gauss–Bessel quadrature: A tool for the evaluation of Barnett–Coulson/Löwdin functions
Authors: Bouferguene Ahmed , Safouhi Hassan 
Published: May 2006

AbstractIn previous work, we analyzed the numerical efficiency of several algorithms that can be used to evaluate the so‐called Barnett–Coulson/Löwdin functions (BCLFs). It was shown that series representations of these functions are generally not recommended in the neighborhood of the cusp because of their poor convergence (logarithmic convergence). In the present work, we propose to evaluate BCLFs using its symmetric integral representation combined with a tailored Gauss quadrature. The new method is shown to be capable of achieving acceptable accuracy, as illustrated by the numerical values obtained for two‐center overlap integrals, which agree with previously published results. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Analysing capture–recapture data when some variables of heterogeneous catchability are not collected or asked in all registrations
Authors: Zwane Eugene N. , van der Heijden Peter G. M. 
Published: May 2006

AbstractRegistrations in epidemiological studies suffer from incompleteness, thus a general consensus is to use capture–recapture models. Lately, there has been a thrust to incorporate covariates which relate to the capture probabilities in order to improve the estimate of population size. Current approaches utilize covariates observed in all the pertinent registrations. In epidemiological applications, one often encounters capture–recapture data where some covariates are measured by some but not by all of the registrations under scrutiny. In this article, the usefulness of these types of covariates is evaluated and furthermore a methodology for analysing such capture–recapture data is presented. The methodology is illustrated by applying it to data on neural tube defects in the Netherlands. Copyright © 2006 John Wiley & Sons, Ltd.
Variable selection and raking in propensity scoring
Authors: Judkins David R. , Morganstein David , Zador Paul , Piesse Andrea , Barrett Brandon , Mukhopadhyay Pushpal 
Published: May 2006

AbstractThis paper discusses some practical issues in applying propensity scoring in the context of endpoint analysis in a pre‐/posttest longitudinal design with an ordinal measure of treatment intensity and a high‐dimensional potential covariate space: how many covariates to include in propensity models; how to evaluate the adequacy of tentative propensity models; and how to tailor models to provide hypercontrol on a limited subset of covariates. These issues arose in the evaluation of a health communication program. Copyright © 2006 John Wiley & Sons, Ltd.
Arab Behaviour Towards Israel: Strategic Avoidance or Exploiting Opportunities?
Authors: DEROUEN KARL , SPRECHER CHRISTOPHER 
Published: May 2006

Scholars often observe that the foreign policies of states are not made in a vacuum but rather are determined or moulded to a significant degree by the external and internal actions of rivals. Domestic unrest is often considered a potential impetus for changing strategic behaviour. Leaders may be tempted to employ force externally to divert attention away from domestic unrest. The intended result is a ‘rally round the flag’ effect that culminates in higher approval/support for the executive as citizens forget about domestic problems and pay attention to a common adversary. One implication of this sort of ‘diversion’ is that potential scapegoats might employ strategic behaviour to avoid becoming a diversionary target. In other words, when they witness domestic unrest in a rival state, they worry that the rival may lash out at them and thus engage in ‘strategic avoidance’.Conversely, strategic behaviour may lead to a greater chance that the potential ‘diverter’ will itself be targeted for hostile behaviour. Erstwhile scapegoats may view periods of social unrest such as elections, domestic political protests or unstable cabinet structures in the other country as convenient and favourable times to escalate hostility. Such situations are viewed as opportunities that are ripe for exploitation.Alastair Smith's work has been extended to both the US case and a comparative cross-national study. Our purpose here is to extend this line of inquiry by looking at a region of the world locked in a long-term hostile relationship; namely, the Middle East. Our approach builds upon previous research that addresses the strategic interaction of enduring rivals.
Demotion and Dissent in the Canadian Liberal Party
Authors: KAM CHRISTOPHER 
Published: May 2006

Those who have not witnessed the making of a government have reason to be happier than those who have. It is a thoroughly unpleasant and discreditable business in which merit is disregarded, loyal service is without value, influence is the most important factor and geography and religion are important supplementary considerations.The Borden Ministry was composed under standard conditions, and was not, therefore, nearly as able, honest, or as industrious an administrative aggregation as could have been had from the material available … There were some broken hearts – in one instance, literally. In others, philosophy came to the rescue, but the pills were large and the swallowing was bitter.Paul BilkeyPrime ministers can typically rely on ideological agreement and norms of loyalty to deliver them a modicum of party cohesion. Beyond that, they have at their disposal a variety of institutional tools with which to enforce discipline. The powers to invoke the confidence convention and to dissolve parliament are the most well known and powerful of these tools, but these heavy-handed measures are ill-suited for securing unity on an on-going basis. The prime minister's monopoly over the distribution of preferment is a far more reliable means of ensuring members' loyalty. The rules of the game are simple: if the member of parliament (MP) wishes to climb the parliamentary career ladder, he or she must toe the party line. The prime minister's power over MPs' parliamentary careers is not without limit, of course. Some MPs must be brought into cabinet because they are too powerful and dangerous to leave on the backbench where they can openly challenge the prime minister.
PERIOD AND COHORT DYNAMICS IN FERTILITY NORMS AT THE ONSET OF THE DEMOGRAPHIC TRANSITION IN KENYA 1978–1998
Authors: WHITE R. G. , HALL C. , WOLFF B. 
Published: May 2006

Summary.A characteristic of African pre-transitional fertility regimes is large ideal family size. This has been used to support claims of cultural entrenchment of high fertility. Yet in Kenya fertility rates have fallen. In this paper this fall is explored in relation to trends in fertility norms and attitudes using four sequential cross-sectional surveys spanning the fertility transition in Kenya (1978, 1984, 1989 and 1998). The most rapid fall in the reported ideal family size occurred between 1984 and 1989, whilst the most rapid fall in the total fertility rate occurred 5 to 10 years later, between 1989 and 1998. Thus these data, spanning the fertility transition in Kenya, support the traditional demographic model that demand for fertility limitation drives fertility decline. These data also suggest that the decline in fertility norms over time was partly a period effect, as the reported ideal family size was seen to fall simultaneously in all age cohorts, and partly a cohort effect, as older age cohorts reporting higher ideal family sizes were replaced by younger cohorts reporting lower ideal family sizes. These data also suggest that a new fertility norm of four children may have developed by 1989 and continued until 1998. This is consistent with, and perhaps could have been used to predict, the stall in the Kenyan fertility decline after 1998.
Why are head and neck cancer clinicians not measuring quality of life?
Authors: Mehanna H M , Morton R P 
Published: May 2006

Aim: To quantify and qualify the use of quality of life (QOL) measures by head and neck cancer clinicians and to identify any impediments to the use of these measures.Methods: Questionnaire survey of members of the Australia and New Zealand Head and Neck Society.Results: One hundred and twenty-eight of 187 (68.5 per cent) responded. Only 43 (34 per cent) had ever used a QOL questionnaire (QLQ), and only 17 (13 per cent) were currently using one. Impediments to QLQ use included clinicians' perceptions that QLQs were too time-consuming and conferred no proven benefit for clinical management. Nevertheless, 113 (88 per cent) respondents indicated willingness to use a minimum core QLQ – for routine clinical use and for research – but indicated a preference for a short (10–15 questions), quick (less than 10 minutes) questionnaire.Conclusions: Most head and neck cancer clinicians did not use a QOL measure routinely, with impediments to routine use being mainly clinician-based. Most respondents would use a minimum core QOL measure, especially if it were a short, quick consensus questionnaire.
Instability of anomalous viscosity disks around young stellar objects
Authors: YAO Z. R. , LI X. Q. 
Published: May 2006

AbstractAn accretion disk with vertical structure around a young stellar object is investigated, considering anomalous magnetic viscosity. It was found that the I-mode was unstable in the outer disk, and sometimes turned stable in the inner disk, for the standard α model. However, we find that the I-mode is always unstable in the inner disk, owing to the anomalous magnetic viscosity.
Pre-morbid IQ and response to routine outcome assessment
Authors: SLADE MIKE , LEESE MORVEN , GILLARD MATT , KUIPERS ELIZABETH , THORNICROFT GRAHAM 
Published: May 2006

Background. Routine use of standardized outcome measures within adult mental health services is compulsory in many countries, but not common in clinical practice. As well as political and professional factors, one reason may be that there is little empirical evidence of benefit for patients. It is therefore important to identify predictors of response. Pre-morbid intellectual functioning has predicted response to other interventions. This paper tests the hypothesis that pre-morbid IQ impacts on the effectiveness of routine assessment and feedback of outcome measures.Method. The Feedback of Outcomes to Users and Staff (FOCUS) single-blind randomized controlled trial (RCT) investigated routine completion and feedback of outcome measures for 160 (101 intervention, 59 control) adult mental health service patients in Croydon, South London (International Standard RCT Number 16971059).Results. Patients in the top quarter (pre-morbid IQ>110) differentially improved in patient-rated unmet need (adjusted difference 3·4, 95% CI 0·8 to 5·9, p=0·012) and in the top half (pre-morbid IQ>99) in quality of life (adjusted difference −0·6, 95% CI −1·1 to −0·1, p=0·02). The top quarter result remained when controlling for the influence of baseline (p=0·004) and baseline plus follow-up variables (p=0·047).Conclusions. Feedback of routine outcome measures may improve outcome for patients with higher pre-morbid IQ. There is a need to understand more how routine outcome information is used by staff and patients to inform care. If the goal of routine use of outcome measures is to benefit patients directly, then targeted policies are required.
A pilot study of positive mood induction in euthymic bipolar subjects compared with healthy controls
Authors: FARMER ANNE , LAM DOMINIC , SAHAKIAN BARBARA , ROISER JONATHON , BURKE AILBHE , O'NEILL NATHAN , KEATING SAM , SMITH GEORGIA POWELL , McGUFFIN PETER 
Published: May 2006

Background. Demonstrating differences between euthymic bipolar subjects and healthy controls in response to positive (happy) mood induction may help elucidate how mania evolves. This pilot study evaluates the Go task in a reward paradigm as a method for inducing a happy mood state and compares the response of euthymic bipolar subjects and healthy controls.Method. The Sense of Hyperpositive Self Scale, the Tellegen positive and negative adjectives, the Global-Local task and a visual analogue scale for measuring positive affect were administered to 15 euthymic bipolar subjects and 19 age-and-sex-matched healthy control subjects before and after they had performed the Go task in a reward paradigm.Results. Significant differences were found between subjects and controls on several measures at each time-point but there were no differences across the groups across time except for the visual analogue scales, where subjects had a more sustained duration in self-reported happiness compared with controls.Conclusions. This pilot study has shown that a positive affect can be induced in bipolar subjects and controls which can be demonstrated by changes in scores on several tasks. However, only the visual analogue scales showed a significant difference between cases and controls over time. Such tests may prove valuable in furthering understanding about the evolution of manic mood states.
Public intervention in a ‘take-it-or-leave-it’ transaction situation under varying interests of the intervening body
Authors: AANESEN MARGRETHE 
Published: May 2006

Though there are economically based arguments for public intervention in negotiations between private agents, such intervention will often take place as a consequence of political interests. In this paper we discuss how varying political interests of an intervening body affect its intervention mechanism. We derive a unique Bayesian–Nash equilibrium for a two-step, three-player game in which the optimal intervention mechanism (subsidies) and the optimal size of the traded good are decided.The paper has been motivated by the negotiations between a Russian processing plant, causing transboundary, polluting emissions, and Nordic companies offering technology which will reduce the emissions significantly. Nordic governments have intervened in the negotiations and offered subsidies, which is subtracted from the seller's price if trade takes place. Combining the theoretical results and empirical facts we conclude that the Norwegian government seems to have had stronger political interests in this case than did the Finnish government.