bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prevalence of anxiety disorders and anxiety subtypes in patients with Parkinson's disease
Authors: Pontone Gregory M. , Williams James R. , Anderson Karen E. , Chase Gary , Goldstein Susanne A. , Grill Stephen , Hirsch Elaina S. , Lehmann Susan , Little John T. , Margolis Russell L. , Rabins Peter V. , Weiss Howard D. , Marsh Laura 
Published: May 2009

AbstractAnxiety disorders are common in Parkinson's disease (PD), but are not well characterized. This study determined the prevalence and clinical correlates of all DSM‐IV‐TR anxiety disorder diagnoses in a sample of 127 subjects with idiopathic PD who underwent comprehensive assessments administered by a psychiatrist and neurologist. A panel of six psychiatrists with expertise in geriatric psychiatry and/or movement disorders established by consensus all psychiatric diagnoses. Current and lifetime prevalence of at least one anxiety disorder diagnosis was 43% (n = 55) and 49% (n = 63), respectively. Anxiety disorder not otherwise specified, a DSM diagnosis used for anxiety disturbances not meeting criteria for defined subtypes, was the most common diagnosis (30% lifetime prevalence, n = 38). Compared with nonanxious subjects, panic disorder (n = 13) was associated with earlier age of PD onset [50.3 (12.2) vs. 61.0 (13.7) years,P< 0.01], higher rates of motor fluctuations [77% (10/13) vs. 39% (25/64),P= 0.01] and morning dystonia [38% (5/13) vs. 13% (8/62),P< 0.03]. This high prevalence of anxiety disorders, including disturbances often not meeting conventional diagnostic criteria, suggests that anxiety in PD is likely underdiagnosed and undertreated and refined characterization of anxiety disorders in PD is needed. In addition, certain anxiety subtypes may be clinically useful markers associated with disease impact in PD. © 2009 Movement Disorder Society
Exploring indicators for pain rehabilitation: A Delphi study using a multidisciplinary expert panel
Authors: Skjutar Åsa , Christensson Kyllike , Müllersdorf Maria 
Published: May 2009

AbstractObjective: Lack of referral guidelines can cause delayed or even non‐existent rehabilitation for chronic pain patients. Indicators signalling the need for interventions could counteract this delay for pain rehabilitation and thereby prevent deteriorating patient health. This study aimed to explore the indicators of need for pain rehabilitation using a multidisciplinary expert panel working with pain rehabilitation.Methods: A three‐round Delphi study was conducted with a multidisciplinary expert panel (n = 23), each representing one pain rehabilitation unit in Sweden. The expert panel produced indicators, which were then ranked using a four‐point Likert scale.Results: Twenty multi‐faceted indicators for pain rehabilitation were identified. A major part concerned patient problems with activity level, catastrophizing, coping, existential problems, fear avoidance, high pain rating, medication, mental health, motivation, no pain relief, pain spread/increase, psychosocial problems combined with activity problems, psychosocial problems, recovery, and reduced physical function. Furthermore, indicators concerned demographic factors, sick leave, situation in primary health care and work. Finally, tacit knowledge was pointed out as an indicator. The results support previous research but also bring out less quantifiable indicators, such as relying on tacit knowledge while assessing a patient's need for rehabilitation.Conclusion: The indicators for pain rehabilitation were comprehensive, pointing out that needs assessment is complex. Despite reaching consensus on 19 out of 20 indicators, further research is needed to deepen knowledge in this area and to secure a fair assessment of a patient's need for pain rehabilitation. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of spatial variability of cross‐correlated soil properties on bearing capacity of strip footing
Authors: Cho Sung Eun , Park Hyung Choon 
Published: May 2009

AbstractGeotechnical engineering problems are characterized by many sources of uncertainty. Some of these sources are connected to the uncertainties of soil properties involved in the analysis. In this paper, a numerical procedure for a probabilistic analysis that considers the spatial variability of cross‐correlated soil properties is presented and applied to study the bearing capacity of spatially random soil with different autocorrelation distances in the vertical and horizontal directions. The approach integrates a commercial finite difference method and random field theory into the framework of a probabilistic analysis. Two‐dimensional cross‐correlated non‐Gaussian random fields are generated based on a Karhunen–Loève expansion in a manner consistent with a specified marginal distribution function, an autocorrelation function, and cross‐correlation coefficients. A Monte Carlo simulation is then used to determine the statistical response based on the random fields. A series of analyses was performed to study the effects of uncertainty due to the spatial heterogeneity on the bearing capacity of a rough strip footing. The simulations provide insight into the application of uncertainty treatment to geotechnical problems and show the importance of the spatial variability of soil properties with regard to the outcome of a probabilistic assessment. Copyright © 2009 John Wiley & Sons, Ltd.
Gmsh: A 3‐D finite element mesh generator with built‐in pre‐ and post‐processing facilities
Authors: Geuzaine Christophe , Remacle Jean‐François 
Published: May 2009

AbstractGmsh is an open‐source 3‐D finite element grid generator with a build‐in CAD engine and post‐processor. Its design goal is to provide a fast, light and user‐friendly meshing tool with parametric input and advanced visualization capabilities. This paper presents the overall philosophy, the main design choices and some of the original algorithms implemented in Gmsh. Copyright © 2009 John Wiley & Sons, Ltd.
Segregated by neighbourhoods? A portrait of ethnic diversity in the neighbourhoods of the Accra Metropolitan Area, Ghana
Authors: Agyei‐Mensah Samuel , Owusu George 
Published: May 2009

AbstractStudies of urban ethnicity have portrayed ethnic groups as initially concentrating in locations where they live in relatively exclusive residential areas containing few members of other groups. This concentration into ethnic enclaves is commonly regarded as a result of disadvantage and discrimination in the labour and housing markets, coupled with a desire for residential concentration to promote and guarantee group cultural, socioeconomic and physical security. To what extent do the neighbourhoods of Accra Metropolitan Area reflect these urban ethnicity patterns, and what are the factors shaping the concentration of ethnic groups in the city? Using the Location Quotient Index based on census data, the paper examines the degree of ethnic diversity and concentration in the neighbourhoods of Accra. The findings of the study reveal that Accra is not following a Western model of segregation, neither is there a single model of African segregation, but rather many African trajectories. Economic segregation is the organising force underlying residential segregation in Accra, and this operates through several social markers, one of which remains the ethnic history of migration to Accra. Copyright © 2009 John Wiley & Sons, Ltd.
Bringing norms back in: a theoretical and empirical discussion of their importance for understanding demographic behaviour
Authors: Liefbroer Aart C. , Billari Francesco C. 
Published: May 2009

AbstractAlthough the life‐course perspective emphasizes the importance of the concept of social norms for understanding demographic choices, the usefulness of this concept is heavily debated. In particular, it has been questioned whether social norms are still important in post‐modern societies, and whether societal expectations can really be called norms if no sanctions are attached to them. In this article, we review the theoretical and empirical literature, highlight the potential usefulness of the concept, and illustrate its importance by presenting empirical data on the existence of norms concerning demographic choices in The Netherlands, one of the most individualized countries in the world. Copyright © 2009 John Wiley & Sons, Ltd.
Internal migration in Britain, 2000–01, examined through an area classification framework
Authors: Dennett Adam , Stillwell John 
Published: May 2009

AbstractThis paper explores the age variations in origin–destination migration data from the 2001 UK Census. It does so using a national district classification as a framework for summarising what is a series of matrices, each containing very large numbers of cells. The results demonstrate how migration propensities and patterns vary between different types of district, providing new insights into the processes through which the population is redistributed throughout Great Britain. Copyright © 2009 John Wiley & Sons, Ltd.
Who's crossing the border: new data on undocumented immigrants to the United States
Authors: Weeks John R. , Stoler Justin , Jankowski Piotr 
Published: May 2009

AbstractThe majority of undocumented immigrants to the United States enter through the southern border and most are from Mexico. Researchers in the US have been able to create estimates of how many unauthorised immigrants come from each country, but there has been little research on the geographical origins of immigrants from within Mexico. In this research we make use of a unique unduplicated file of people detained at or near the border by the US Border Patrol during the years 1999 to 2006. By focusing especially on the population aged 20–34, we are able to create a migration propensity index, which is the ratio of detainees from each state in Mexico to the population aged 20–34 in that state. The analysis of this index confirms the few other sources of information suggesting that migration from Mexico to the US is increasingly occurring from the more southern, indigenous states. A multiple regression analysis of the migration propensity index and state‐level variables finds that the death rate from accidents and violence among men aged 20–34 is the single most important predictor of a state's migration propensity index. This is related to a variety of factors indicating that migrants come from states with the poorest economic infrastructure. We discuss the implications of these shifts for both receiving and sending communities. Copyright © 2009 John Wiley & Sons, Ltd.
Studies of the EPR parameters and defect structure for tetrahedral Fe3+ centers in zinc oxide
Authors: Yang Zi‐Yuan 
Published: May 2009

AbstractThe relations between the electron paramagnetic resonance (EPR) parameters and crystal structure of Fe3+:ZnO crystals have been established. On the basis of this, the EPR parameters D, (a‐F) and the zero‐field splitting (ZFS) δ1, δ2 of the ground state for Fe3+ in Fe3+:ZnO crystals are theoretically investigated using the complete diagonalization method (CDM). The theoretical second‐order EPR parameter D, the fourth‐order EPR parameter (a‐F), and the ZFS of the ground state: δ1, δ2 for Fe3+ in Fe3+:ZnO yield a good agreement with experimental findings when the three O2– ions below the Fe3+ ion rotate by Δθ in the range 0.475–0.562° away from the [111] axis. Hence, the local structure distortion effect plays an important role in explaining the spectroscopic properties of Fe3+ ions in Fe3+:ZnO crystals. Our approach takes into account the spin–orbit (SO) interaction as well as the spin–spin (SS), spin–other–orbit (SOO), and orbit–orbit (OO) interactions omitted in previous studies. This shows that although the SO interaction is the most important one, the contributions to the EPR parameters from the other three interactions are appreciable and should not be omitted, especially for the EPR parameter D. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First‐principles calculations of structural, elastic and electronic properties of Ni2MnZ (Z = Al, Ga and In) Heusler alloys
Authors: Rached H. , Rached D. , Khenata R. , Reshak Ali H. , Rabah M. 
Published: May 2009

AbstractWe have performed ab‐initio density‐functional theory self‐consistent calculations using the full‐potential linear muffin‐tin orbital method within local spin‐density approximation to study the electronic and magnetic properties of Ni2MnZ (Z = Al, Ga and In) in L21 structure. The magnetic phase stability is determined from the total energy calculations for both the nonmagnetic (NM) and magnetic (M) phases. The theoretical calculations clearly indicate that at both ambient and high pressures, the magnetic phase is more stable than the nonmagnetic phase. The elastic constants at equilibrium are also determined. We derived the bulk and shear moduli, Young's modulus, and Poisson's ratio. The Debye temperature of Ni2MnZ was estimated from the average sound velocity. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic and elastic properties of perovskite‐like W3NiC, W3NiN and Co3WC from first‐principles calculations
Authors: Suetin Dmitrii V. , Bannikov Vyacheslav V. , Shein Igor R. , Ivanovskii Alexander L. 
Published: May 2009

AbstractWe have performed ab initio total energy calculations using the full‐potential linearized augmented plane wave (FP‐LAPW) method with the generalized gradient approximation (GGA) for the exchange–correlation potential to investigate structural, elastic, cohesive, electronic and magnetic properties of the tungsten‐containing perovskite‐like phases W3NiC, W3NiN and Co3WC. The optimized lattice parameters, independent elastic constants (Cij), bulk moduli (B) and shear moduli (G), as well as densities of electronic states and cohesive and formation energies are obtained and analyzed for the first time. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Light emitting FET based‐on spatially selective doping of Eu in AlGaN/GaN HEMT
Authors: Okada Hiroshi , Takemoto Kazumasa , Oikawa Fumitake , Furukawa Yuzo , Wakahara Akihiro , Sato Shin‐ichiro , Ohshima Takeshi 
Published: May 2009

AbstractLight emitting field effect transistor (FET) based‐on AlGaN/GaN high electron mobility transistor (HEMT) structure with spatially selective doping of rare‐earth ions (REIs) as a luminescence center in the channel is proposed and investigated. Fabricated device showed excellent I –V characteristics as a transistor with gate control. By applying a drain bias of 20 V, red emission suggesting a luminescence from Eu ion was clearly observed. Applying a negative bias to the Schottky gate decreased the luminescence intensity (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of asymmetric GaN/InGaN multiple quantum well
Authors: Chen Z. Z. , Qi S. L. , Liu P. , Yu T. J. , Wang C. D. , He Z. K. , Tong Y. Z. , Pan Y. B. , Hao M. S. , Zhang G. Y. 
Published: May 2009

AbstractThe microstructure and electronic structure of the asymmetric GaN/InGaN multiple quantum well (MQW) light emitting diodes are characterized by transmission electron microscope (TEM), cathodoluminescence (CL) and capacitance‐voltage (C‐V) measurements. In TEM images, the asymmetric structure of InGaN/GaN MQW are observed as designed with different width of QWs and barriers, and indium content in QWs as well. In high‐resolution TEM images, the InGaN quantum wells and GaN barriers show the same lattice constant, and some degradation can be seen at the bottom of each InGaN QW. There are two emission peaks, 450 and 530 nm in CL spectrum, similar to the ones in electroluminescence spectrum. The double emission peaks are assigned to the irradiative recombination in different InGaN QWs. From the C‐V data, the apparent carrier concentration in the asymmetric MQW is calculated. There are five obvious peaks which are well explained by an energy band scheme of InGaN/GaN MQW. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diffusion and recombination of degenerate carrier plasma in GaN
Authors: Malinauskas Tadas , Jarasiunas Kestutis , Heuken Michael , Scholz Ferdinand , Brückner Peter 
Published: May 2009

AbstractThe carrier diffusion and recombination were investigated by light induced transient grating technique (LITG) in a HVPE grown GaN at intense band‐to‐band excitation. The given measurements in high structural quality layers revealed the features of an intrinsic crystal – carrier‐density dependent recombination and diffusion. It was found that ambipolar carrier diffusion coefficient D and carrier lifetime τ were dependent on excitation intensity and therefore varied during the grating decay. The values of D = 1.5 cm2/s and τ = 3.8 ns were found for carrier densities ∼1018 cm–3, while at the highest excitation used (n∼1020 cm–3) the D value reached 4.1 cm2/s, and τ decreased to 1.3 ns. The numerical modelling of carrier dynamics confirmed that the observed increase of diffusion coefficient with carrier density was due to degeneracy of carrier plasma, while short carrier lifetime at high carrier density was ruled by a bimolecular recombination. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Impact of the field induced polarization space‐charge on the characteristics of AlGaN/GaN HEMT: Self‐consistent simulation study
Authors: Balaz D. , Kalna K. , Kuball M. , Uren M. J. , Asenov A. 
Published: May 2009

AbstractUsing self‐consistent numerical simulation we have studied the impact of the field induced polarization on the characteristics of AlGaN/GaN high electron mobility transistors (HEMTs). The strain induced by external electric fields is on top of the built‐in strain due to lattice mismatch. It has been suggested that this additional strain can play a role in device degradation and failure (J. Joh and J. del Alamo, Mechanisms for Electrical Degradation of GaN High‐Electron Mobility Transistors, IEDM Tech. Dig., pp. 415–418, Dec. (2006) [1]). The study is carried out using commercial TCAD tools carefully calibrated against the measured characteristics of 0.25 μm physical gate length transistors. A coupled model for piezoelectric materials, including the impact of the field, is used to determine the strain and thus the polarization in the device. The spatial charge distribution is derived from the gradient of the polarization and is fed back self‐consistently to the simulator. Results with and without the field‐induced polarization are compared and discussed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tunneling effects in short period strained AlN/GaN superlattices
Authors: Valcheva E. , Kirilov K. , Monemar B. , Amano H. , Akasaki I. 
Published: May 2009

AbstractWe study electronic conduction of short period strained GaN/AlN superlattices. The mechanisms of current transport perpendicular to the layers were studied, with an emphasis on the elastic and inelastic tunneling through the AlN barriers. Electron transport as a function of temperature is examined in I‐V, G‐V (first derivative dI/dV). The current and the conductance show nonlinear oscillatory character. The observed characteristics are interpreted as sequential resonant tunneling through AlN barriers and reveal negative differential conductivity (NDC). (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling analysis of AlN and AlGaN HVPE
Authors: Segal A. S. , Bazarevskiy D. S. , Bogdanov M. V. , Yakovlev E. V. 
Published: May 2009

AbstractComprehensive model of AlN and AlGaN HVPE is developed. The model combines detailed description of the transport processes and quasi‐thermodynamic model of surface kinetics at the Al/Ga metal surfaces and AlN/AlGaN crystal surfaces. It is shown with the model that HCl dominantly converts into trichloride AlCl3 in the Al source but into monochloride GaCl in the Ga source. Then, AlN grows from AlCl3 under essentially non‐equilibrium conditions while GaN – from GaCl under near‐equilibrium conditions. The revealed differences between the AlN and GaN growth features explain many experimentally observed phenomena, including a sharp saturated behavior of the AlN growth rate in variation of the precursors flow rates and a strong effect of carrier H2 on the AlGaN composition. Generally, the model predicts a high sensitivity of the AlGaN composition to variation of the species flow rates due to their effect on the Ga incorporation. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of polarity dependent InN{0001} decomposition in N2 and H2 ambient
Authors: Togashi R. , Kamoshita T. , Adachi H. , Murakami H. , Kumagai Y. , Koukitu A. 
Published: May 2009

AbstractThe polarity dependence of decomposition of the (0001) In‐ and (000$ \bar 1 $) N‐polarity InN layers grown by hydride vapor phase epitaxy (HVPE) on freestanding GaN substrates was investigated. In flowing N2, In‐ and N‐polarity InN layers start to decompose over 550 and 610 °C, respectively. Therefore, the N‐polarity InN layer is more stable than the In‐polarity InN layer. On the other hand, in flowing H2, InN layers of both polarities start to react with H2 at a low temperature of 350 °C leaving In droplets on the surfaces. Further more, the decomposition rate of the N‐polarity InN layer is larger than that of the In‐polarity InN layer below approximately 450 °C, while the decomposition rate of the In‐polarity InN layer is larger than that of the N‐polarity InN above 450 °C. An Arrhenius plot of the decomposition rates revealed that the activation energies, EA, for the decomposition reactions of In‐ and N‐ polarity InN layers are 168 and 107 kJ/mol, respectively, which are much smaller than that for GaN and AlN decomposition. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metastable cubic InN layers on GaAs (001) substrates grown by MBE: Growth condition and crystal structure
Authors: Sanorpim Sakuntam , Jantawongrit Papaporn , Kuntharin Sman , Thanachayanont Chanchana , Nakamura Teruyuki , Katayama Ryuji , Onabe Kentaro 
Published: May 2009

AbstractTransmission electron microscopy and high resolution X‐ray diffraction were applied to characterize the crystal structure and its modification in c‐InN layers on GaAs (001) substrates grown by rf‐plasma assisted molecular beam epitaxy. The layer quality was shown to depend on growth conditions, namely In‐ and N‐rich conditions. The best quality of c‐InN layers was achieved by “stoichiometric” growth under the In‐rich condition, resulting in In‐rich layers with a small amount of hexagonal‐phase inclusion (∼8%). On the other hand, nucleation and growth of N‐rich layers are shown to result in a high density of stacking faults which drastically decreases toward the InN surface. It is argued that the presence of stacking faults contributes to the structural modification in these layers. We found that the existence of a structural modification from cubic to mixed cubic/hexagonal phase in microstructure of the N‐rich layers exhibit higher hexagonal‐phase incorporation than that of the In‐rich layers. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence and excitation spectrum of Mg‐doped p‐type AlXGa1–XN
Authors: Suzuki M. , Sawai S. , Fukui K. , Nagamatsu K. , Amano H. 
Published: May 2009

AbstractWe have been measured the near band edge photoluminescence (PL) and photoluminescence excitation (PLE) spectra of Mg doped AlGaN. PL and PLE peak energies were almost corresponding to those of undoped AlGaN. From the temperature dependent measurement of the PL spectra, the PL peak energy shift as a function of temperature showed S ‐shaped behaviour. These results suggest that the mechanisms of the near band edge PL of AlGaN:Mg are basically similar to those of undoped AlGaN. Using the known spectral feature of undoped AlGaN which consists of main and LO phonon replica emission bands at even interval energy and same line width, the spectral decomposition of the PL spectrum reveals an additional band which is expected as the transition to the acceptor level arising from Mg doping. The temperature dependences of its peak energy and intensity suggest relative temperature shift of the acceptor level and also may imply the existence of another relaxation pathway. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)