bluuebunny/crossref_metadata_2025_split huggingface dataset:
High spatial resolution micro‐Raman temperature measurements of nitride devices (FETs and light emitters)
Authors: Kuball M. , Pomeroy J. W. , Rajasingam S. , Sarua A. , Uren M. J. , Martin T. , Lell A. , Härle V. 
Published: April 2005

AbstractThe cover picture of the present issue of physica status solidi (a) is a temperature map of a AlGaN/GaN heterostructure field effect transistor (HFET) obtained using micro‐Raman spectroscopy. The inset shows a photograph of the device with source (S), gate (G) and drain (D) positions marked. The paper by M. Kuball et al. [1] is an invited presentation from the International Workshop on Nitride Semiconductors (IWN 2004).In the Rapid Research Letter by B. Lamprecht et al. [2] the authors report on the successful fabrication and characterization of working organic photodiodes deposited on ordinary newspaper sheets as an example for a flexible and very rough substrate with unfortunate mechanical properties.
Tamm and Shockley states in two superlattices coupled by a perturbed interface
Authors: Kłos Jarosław 
Published: April 2005

AbstractInterface‐localized electronic states are investigated in a system composed of two identical superlattices coupled by a perturbed interface (with symmetric potential wells). A perturbation, in the form of a Dirac delta peak, is introduced on the interface. The effect of the symmetry point in which the superlattices communicate, as well as that of the perturbation strength, on conditions of Tamm and Shockley state existence are examined. The analysis is completed with numerical calculation of localized states in a system composed of two AlxGa1–xAs ‘square‐potential’ superlattices. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electro‐optic investigation of the Coherent Hall Effect in semiconductor superlattices
Authors: Hummel Anne Beate , Blöser Claudia , Bauer Tobias , Roskos Hartmut G. , Kosevich Yuriy A. , Köhler Klaus 
Published: April 2005

AbstractAfter the first observation of the Coherent Hall Effect in a GaAs/Al0.3Ga0.7As superlattice by means of THz‐emission spectroscopy, the dynamics of impulsively excited electron wavepackets in crossed electric and magnetic fields has now been investigated in more detail by reflective electro‐optic sampling (REOS). In agreement with the predictions of a semiclassical model, the experiments show the existence of two strictly separated regimes of charge‐carrier motion depending on the ratio E/B of applied electric and magnetic field. Both, the magneto‐Bloch regime for dominating electric field and the cyclotron‐like regime of motion for dominating magnetic field, exhibit a characteristic frequency dependence of the wavepacket oscillations on the external fields. The REOS measurements supplement our results achieved by THz‐emission spectroscopy by covering a much larger range of experimental parameters because REOS is not affected by absorption by the cryostat windows of our set‐up as is the THz radiation at frequencies above 2 THz, and the detection of high oscillation frequencies is possible. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dephasing by electron–phonon interaction in an AB ring with an embedded quantum dot
Authors: Ueda Akiko , Eto Mikio 
Published: April 2005

AbstractWe study the dephasing effect on the transport properties in an Aharonov–Bohm ring with an embedded quantum dot, due to the electron–phonon interaction. The differential conductance is calculated under finite bias using Keldysh Green function. The electron–phonon interaction is treated (i) by the canonical transformation, or (ii) by the second‐order perturbation. By the latter method, we find that the Fano resonance is suppressed by the electron–phonon interaction and that the suppression increases with increasing bias voltage. The calculations by the former method do not yield the bias‐voltage dependence of the dephasing effect. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical probing of the spin state of a single magnetic ion in an individual quantum dot
Authors: Besombes L. , Leger Y. , Maingault L. , Ferrand D. , Cibert J. , Mariette H. 
Published: April 2005

AbstractThe magnetic state of a single magnetic ion (Mn2+) embedded in an individual quantum dot is optically probed using micro‐spectroscopy. The fine structure of a confined exciton in the exchange field of the single Mn2+ ion is analyzed in detail. At zero magnetic field, the exciton–Mn exchange coupling lifts the degeneracy of the six Mn spin projections. Under magnetic field, the electron–Mn interaction induces a mixing of the bright and dark exciton states. Magneto‐optic measurements reveals that the polarisation of the Mn2+ spin distribution is controlled by the magnetic field and an effective manganese temperature depending on both the lattice temperature and the density of photo‐created carriers. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Validation of a high‐throughput absorption, distribution, metabolism, and excretion (ADME) system and results for 60 literature compounds
Authors: Yan Zhixia , Lu Chuang , Wu Jing‐Tao , Elvebak Larry , Brockman Adam 
Published: April 2005

AbstractA high‐throughput analytical system for the support of absorption, distribution, metabolism, and excretion (ADME) was constructed in collaboration with Gubbs Inc. to commercialize corresponding software. We sought to quickly build and validate this system for microsomal clearance assessment using 60 commercially available non‐proprietary compounds that are non‐DEA‐restricted in addition to 36 proprietary Millennium compounds that had already been assessed using a low‐throughput infrastructure. The system was constructed such that a ∼45 second total cycle time was achieved injection‐to‐injection. Software was successfully coded to enable the analyst to submit multiple batches, and modify multiple methods very quickly for use with Applied Biosystems Analyst™ 1.3. After acquisition the software was used to simultaneously integrate multiple injection chromatograms, regress the data, and calculate clearance such that all of the data could be easily and immediately reviewed by both bioanalytical and enzymology personnel. Unfortunately, despite an exhaustive search of the literature, we were unable to find a large number of non‐proprietary compound data for validation, so we provide such a source of data here. Results are presented for the 60 literature compounds that were assessed. A good correlation was observed between literature results for 16 compounds that we were able to find and the results obtained using the system. The Millennium proprietary compounds that we assessed using both low‐ and high‐throughput approaches also correlated well. We present here a system for the support of high‐throughput in vitro ADME analysis and also present the results of 60 non‐proprietary, non‐DEA‐scheduled compounds to facilitate the validation efforts of others. Finally, we present commercially available software to facilitate high‐throughput ADME systems in the community. Copyright © 2005 John Wiley & Sons, Ltd.
Fick's law of diffusion depth profiles applied to the degradation of oxidized polystyrene during ARXPS analysis
Authors: Ménard M. , Paynter R. W. 
Published: April 2005

AbstractAngle‐resolved x‐ray photoelectron spectroscopy (ARXPS) measurements were made, using Al Kα and Mg Kα radiation alternately, on a polystyrene sample that had been exposed to a helium plasma. It was observed that oxygen was introduced into the sample surface by the plasma treatment, and that some of it was lost over a period of 5 h under x‐ray irradiation in the vacuum of the spectrometer. Laplace transforms of Fick's law of diffusion profiles were derived and applied to the data. The ARXPS results obtained in this study are consistent with a sample history in which the oxidation of the polymer surface resulting from exposure to plasma is controlled by a diffusion process, whereas the loss of oxygen during exposure to x‐rays is principally controlled by a first‐order reaction such as the liberation of oxygen (presumably as CO2) from carbon–oxygen groups by the action of radicals created by the ionizing radiation. Copyright © 2005 John Wiley & Sons, Ltd.
Correlation between ultrasound and anatomical findings in fetuses with lower urinary tract obstruction in the first half of pregnancy
Authors: Robyr R. , Benachi A. , Daikha‐Dahmane F. , Martinovich J. , Dumez Y. , Ville Y. 
Published: April 2005

AbstractObjectiveThe prognosis of fetal lower urinary tract obstruction (LUTO) depends upon renal function and also upon the underlying etiology. Precise identification of the latter remains a challenge antenatally. Our objective was to examine the underlying pathology in male fetuses with sonographic evidence of severe and isolated LUTO.MethodsDetailed postmortem examination was carried out after termination of pregnancy in 24 male fetuses presenting before 25 weeks of gestation with ultrasound evidence of isolated severe LUTO.ResultsAll fetuses had megacystis and hyperechogenic kidneys. There was anhydramnios/oligohydramnios and pelvicalyceal dilatation in 20 and 15 cases, respectively. Posterior urethral valves (PUV) were suspected antenatally in 20 cases and urethral atresia was not suspected antenatally. However, postmortem examination of the urethra demonstrated atresia in six cases, severe stenosis in eight cases, PUV in nine cases and an apparently normal urethra in one case. Renal dysplasia was found in all cases but one. Urethral atresia was the most common urethral anomaly at 12–17 weeks. Hydronephrosis was more frequent in cases with PUV (8/9) and urethral stenosis (6/8) than with urethral atresia (0/6). In LUTO presenting in the first and second trimester, hyperechogenic kidneys were predictive of renal dysplasia in 95% of cases. The association of a sagittal diameter of the bladder of at least 40 mm with hydronephrosis before 28 weeks was predictive of PUV with a positive (PPV) and negative (NPV) predictive value of 44.4% and 66.6%, respectively. Absence of hydronephrosis and a sagittal diameter of the bladder of less than 40 mm were predictive of urethral atresia or stenosis with a PPV and NPV of 100% and 47.6%, respectively. The absence of hydronephrosis was predictive of urethral atresia with a PPV and NPV of 66.6% and 100%, respectively.ConclusionLUTO in a male fetus presenting with megacystis in the first or second trimester of pregnancy is as likely to reflect urethral atresia or stenosis as it is PUV. The size of the bladder and the presence of hydronephrosis should be considered in order to improve prenatal diagnosis and counseling. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Implicit difference methods for parabolic functional differential equations
Authors: Czernous W. , Kamont Z. 
Published: April 2005

AbstractWe present a new class of numerical methods for the solution of quasilinear parabolic functional differential equations. The numerical methods are difference schemes which are implicit with respect to time variable. We give a complete convergence analysis for the methods and we show by an example that the new methods are considerable better that the explicit schemes. The proof of the stability is based on a comparison technique with nonlinear estimates of the Perron type for given operators. Results obtained in the paper can be applied to differential integral problems and equations with retarded variables.
Randomized controlled augmentation trials in clozapine-resistant schizophrenic patients: a critical review
Authors: Kontaxakis Vassilis P. , Ferentinos Panayotis P. , Havaki-Kontaxaki Beata J. , Roukas Dimitris K. 
Published: April 2005

AbstractApproximately 40–70% of treatment-resistant schizophrenic patients fail to benefit from clozapine monotherapy or are partial responders. During the last years several clozapine adjunctive agents have come into clinical practice. This study aims to critically review all published randomized, double-blind, placebo-controlled clinical trials (RCTs) regarding the efficacy and safety of adjunctive agents in clozapine-resistant schizophrenic or schizoaffective patients. A MEDLINE search for RCTs on clozapine adjunctive agents published from January 1980 to February 2004 was conducted. All identified papers were critically reviewed and examined against several methodological features as well as clinical and pharmacological parameters. Eleven trials including 270 patients, partial or non-responders to clozapine, assessed the efficacy of sulpiride, lithium, lamotrigine, fluoxetine, glycine, d-serine, d-cycloserine and ethyl-eicosapentanoate (E-EPA) as clozapine adjuncts. There were eight parallel-group and three crossover trials. The inclusion criteria varied widely. The duration as well as the dosage of clozapine monotherapy were reported adequate in only one trial. Plasma clozapine levels were assessed in only three trials. Main side-effects reported were hypersalivation, sedation, diarrhea, nausea, hyperprolactinaemia. The outcome favored clozapine augmentation with sulpiride, lamotrigine and E-EPA. Lithium was shown to benefit only schizoaffective patients. However, the methodological shortcomings of trials analyzed limit the impact of evidence provided.
Using size-based indicators to evaluate the ecosystem effects of fishing
Authors: Shin Yunne-Jai , Rochet Marie-Joëlle , Jennings Simon , Field John G. , Gislason Henrik 
Published: April 2005

AbstractThe usefulness and relevance of size-based indicators (SBIs) to an ecosystem approach to fisheries (EAF) are assessed through a review of empirical and modelling studies. SBIs are tabulated along with their definitions, data requirements, potential biases, availability of time-series, and expected directions of change in response to fishing pressure. They include mean length in a population, mean length in a community, mean maximum length in a community, and the slope and intercept of size spectra. Most SBIs can be derived from fairly standard survey data on length frequencies, without the need for elaborate models. Possible fishing- and environment-induced effects are analysed to distinguish between the two causes, and hypothetical cases of reference directions of change are tabulated. We conclude that no single SBI can serve as an effective overall indicator of heavy fishing pressure. Rather, suites of SBI should be selected, and reference directions may be more useful than reference points. Further modelling and worldwide comparative studies are needed to provide better understanding of SBIs and the factors affecting them. The slow response to fishing pressure reflects the complexity of community interactions and ecosystem responses, and prohibits their application in the context of short-term (annual) tactical fisheries management. However, movement towards longer-term (5–10 years) strategic management in EAF should facilitate their use.
Pregnancy outcomes in in vitro fertilization cycles with serum estradiol drop prior to human chorionic gonadotropin
Authors: Styer A.K. , Jackson K.V. , Hornstein M.D. , Racowsky C. , Ginsburg E.S. , Gargiulo A.R. 
Published: April 2005

AbstractObjectiveTo study the effect of an unpredictable drop in serum estradiol prior to hCG administration on pregnancy outcomes in in vitro fertilization cycles.Methods3653 consecutive IVF cycles from January 1, 1998 to December 31, 2000 at Brigham and Women's Hospital were reviewed, and 65 cycles in which oocyte retrieval (ER) was performed following a drop in serum estradiol (E2) not associated with intentional withdrawal of gonadotropins were identified. Daily gonadotropin dose was decreased at some time in 25 of these cycles, while the remaining 40 cycles did not have a reduction in gonadotropin dose. A retrospective case‐control study of the respective live birth rates and pregnancy loss rates of patients with unpredictable E2 drops in the 65 study cycles were compared to 65 age matched controls.ResultsLive birth rates (32% vs. 35%, p = 0.72) and pregnancy loss rates (28% vs. 30%, p = 0.76) were similar for all study and control groups respectively. There were no differences in live birth and pregnancy loss rates in cycles undergoing gonadotropin dose reduction (40% vs. 44%, p = 0.78 and 29% vs. 39%, p = 0.70) and cycles without gonadotropin dose reduction (28% vs. 30%, p = 0.81 and 27% vs. 20%, p = 0.72).ConclusionsIn the absence of coasting, a drop in serum estradiol levels during GnRH‐agonist downregulated controlled ovarian hyperstimulation for IVF prior to hCG is not associated with a decrease in live birth rates or pregnancy loss rates.
Assessment of the three‐dimensional relationship of the ossific nuclei and cartilaginous anlagen in congenital clubfoot by 3‐D MRI
Authors: Itohara Tomonobu , Sugamoto Kazuomi , Shimizu Nobuyiki , Ohno Ikko , Tanaka Hisashi , Nakajima Yoshikazu , Sato Yoshinobu , Yoshikawa Hideki 
Published: April 2005

AbstractPurpose: Radiographic measurement is the usual method used to objectively determine the extent of a congenital clubfoot deformity. Although radiographs have been used clinically to estimate the size and location of tarsal bones through measurements of the ossific nuclei, it is not clear to what extent these relationships are actually reflected in these measurements. So, we used a 3‐D MRI system that could more objectively estimate sizes and positional relationships.Material and method: We evaluated 5 patients with unilateral congenital clubfoot deformity. Magnetic resonance imaging was performed of both feet using 1.5‐T magnet. Based on the resulting magnetic resonance imaging volume data, a three‐dimensional surface bone model was reconstructed by the Marching Cubes method. We used this model to perform a comparative analysis of the volume and volume ratio of each cartilaginous anlage and ossific nucleus, the length of the talus and the calcaneus, and the position of the center of gravity of ossific nuclei within the cartilaginous anlagen. We measured the relationship between the ossific nuclei and cartilaginous anlagen in the talus and calcaneus of patients with unilateral clubfoot deformity.Result: In clubfeet talus volume was reduced by 20.1% and calcaneal volume was reduced by 15.7%. Furthermore, the volume of the talar ossific nucleus was reduced by 42.6% and that of the calcaneal ossific nucleus was reduced by 12.1%. The length of the clubfoot talus was 8.2% shorter than normal, and that of the calcaneus was 4.8% shorter.Conclusion: The assessment technique presented herein was shown to be useful in ascertaining the various pathological characteristics associated with clubfoot. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Real options, irreversible investment and firm uncertainty: New evidence from U.S. firms
Authors: Bulan Laarni T. 
Published: April 2005

AbstractThis paper investigates real options behavior in capital budgeting decisions using a firm‐level panel data set of U.S. companies in the manufacturing sector. Specifically, this paper looks at the relationship between the firm's investment to capital ratio and total firm uncertainty, measured as the volatility of the firm's equity returns. Total firm uncertainty is decomposed into its market, industry and firm‐specific components. Given that the irreversibility of capital is derived from asset‐specificity at the industry level, increased industry uncertainty displays a pronounced negative effect on firm investment consistent with real options behavior. Increased firm‐specific uncertainty is also found to depress firm investment—a result that can be attributed to real options behavior and not just managerial risk aversion. The results are robust to various specifications that control for the firm's investment opportunities that are captured by Tobin's q, cash flow, marginal profitability of capital and firm leverage.
Investment, irreversibility, and options: An empirical framework
Authors: Shaanan Joseph 
Published: April 2005

AbstractThe paper presents an empirical test of the impact of irreversibility on threshold return levels and on investment. These tests permit an examination of a key concept and some predictions of irreversible investment theory, which links the option pricing approach with Tobin's q theory. A key feature of the paper is that estimates of the threshold return levels required for investment, which account for both options to invest and disinvest, are obtained internally from the empirical model. The study employs a panel data set consisting of U.S. manufacturing firms and finds that irreversibility, through its negative impact on marginal put options and the resulting increase in threshold returns, reduces investment in two of the four groups of firms studied.
Real options and the value of generation capacity in the German electricity market
Authors: Hlouskova Jaroslava , Kossmeier Stephan , Obersteiner Michael , Schnabl Alexander 
Published: April 2005

AbstractIn this paper we implement a real options model for the unit commitment problem of an electricity producing turbine in a liberalized market. The model accounts for various operating constraints of the turbine. Price uncertainty is captured by a mean reverting process with jumps and time‐varying means to account for seasonality. We demonstrate how the model can be used to value an electricity producing turbine, make profit‐maximizing commitment decisions and compute risk profiles of generating assets for risk management purposes.
The Politics of the Welfare State: Canada, Sweden, and the United
States
Authors: White Linda A. 
Published: April 2005

The Politics of the Welfare State: Canada, Sweden, and the United
States, Gregg M. Olsen, Toronto: Oxford University Press, 2002, pp. vi, 258This book presents a familiar puzzle in comparative politics: how are
we to understand variation in the design and scope of social programs and
substantive outcomes for citizens in the three welfare states under
scrutiny. As Olsen argues, all three cases are “advanced,
industrialized, and highly affluent capitalist nations…. and all
three nations enjoy average per capita incomes and standards of living
that are among the highest in the world” (10). Yet we find great
variation on a number of social indicators such as poverty levels, and
income and wealth disparities. All three have also “experienced
marked increases in inequality and welfare state retrenchment in recent
years” (11) but yet “they continue to differ along these
dimensions, even in the face of similar domestic strains and other
exogenous pressures related to global integration” (11). The
question is how do we account for the variation in the use of social
policy to assuage inequalities and respond to these exogenous
pressures.
Workfare: Why Good Social Policy Ideas Go Bad
Authors: Little Margaret 
Published: April 2005

Workfare: Why Good Social Policy Ideas Go Bad, Maeve Quaid, Toronto:
University of Toronto Press, 2002, pp. 244This book begins with the premise that workfare, properly administered, is good social policy. The author dismisses the moral
arguments surrounding this policy: i) that workfare distinguishes the
deserving from the undeserving; ii) that workfare is a form of slavery,
forcing the poor to work in order to survive; iii) that workfare creates
important responsibility for the recipient; iv) that workfare safeguards
welfare recipients' status as citizens able to fully participate in a
democratic society. These are controversial moral assertions about the
merits or demerits of workfare that the author refuses to address.
Instead, the author, as an expert in organizational behaviour and human
resource management, is interested in whether this policy meets the goals
it establishes. If workfare is to lead recipients to greater job prospects
then this is the measuring stick that should be used to assess the success
of workfare, argues Maeve Quaid.