bluuebunny/crossref_metadata_2025_split huggingface dataset:
706‐GHz GaAs CW fundamental‐mode TUNNETT diodes fabricated with molecular layer epitaxy
Authors: Nishizawa J. , Płotka P. , Kurabayashi T. , Makabe H. 
Published: May 2008

AbstractGaAs TUNNET diodes with 75‐nm thick undoped transit‐time layer and 14‐nm thick n+ electric‐field‐inducing layer, fabricated with molecular layer epitaxy, were oscillating in fundamental‐mode, metal, rectangular WR‐1.0 (0.254 × 0.127 mm) resonant cavities at 706 GHz. The continuous wave output power was ‐67 dBm, at the bias current of 600 mA. The frequency range of continuous wave fundamental‐mode TUNNETT diodes fabricated with molecular layer epitaxy extends from 60 GHz (+13 dBm) to 706 GHz. Modulation experiments of lower frequency, 86‐GHz and 163‐GHz, TUNNETTs have shown that TUNNETTs are suitable for broadband communication and other systems at the modulation rate exceeding 2 Gbps. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetotransport through a two‐dimensional hole antidot lattice: Signatures of Berry phase
Authors: Kang Ning , Abe Eisuke , Hashimoto Yoshiaki , Iye Yasuhiro , Katsumoto Shingo 
Published: May 2008

AbstractWe study the low‐field magnetotransport of a twodimensional hole antidot lattice subject to strong spinorbit interaction. The Aharonov‐Bohm type oscillations appearing in the low‐temperature magnetoresistance have components corresponding to h /e and h /2e. We interpret the nodes seen in the h /e oscillations as signatures of the spin‐orbit Berry phase, based on a simple simulation taking into account its contribution. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Scale‐dependent verification of ensemble forecasts
Authors: Jung Thomas , Leutbecher Martin 
Published: May 2008

AbstractA scale‐dependent verification of the ECMWF ensemble prediction system (EPS) in the Northern Hemisphere is presented. The relationship between spread and skill is investigated alongside probabilistic forecast skill for planetary, synoptic and subsynoptic spectral bands. Since the ECMWF model is a spectral model, the three spectral bands have been isolated using total and zonal wavenumber filters. Diagnosed overdispersiveness of ECMWF EPS in the short range is primarily due to excessive amounts of spread on synoptic scales. Diagnosed underdispersiveness of the ensemble beyond day 5 of the forecast can be explained by too little spread on both synoptic and planetary scales. Copyright © 2008 Royal Meteorological Society
Conditional nonlinear optimal perturbation of a T21L3 quasi‐geostrophic model
Authors: Jiang Zhina , Mu Mu , Wang Donghai 
Published: May 2008

AbstractConditional nonlinear optimal perturbation (CNOP) is defined as an initial perturbation that makes the cost function attain the maximum at a prescribed forecast time with physical constraint conditions, which is a natural generalization of the linear singular vector (LSV) into the nonlinear regime. In this paper, CNOPs of a T21L3 quasi‐geostrophic (QG) spectral model in three kinds of norms are obtained numerically by solving nonlinear optimization problems, and further compared with their linear counterparts, namely LSVs.Results reveal that CNOPs do depend, as LSVs do, on the norm chosen. The stream‐function‐squared norm yields small‐scale disturbances; the results obtained by total‐energy norm are characterized by intermediate‐scale disturbances; and in the case of the enstrophy norm, CNOPs are typified by large‐scale disturbances with large zonal flow contribution. If the linear approximation is valid, CNOP shows great resemblance to LSV, both of which are much localized in cases of the stream‐function‐squared and total‐energy norms. However, with the increasing of the optimization time interval and/or the magnitude of the initial constraint condition, CNOP has less localized structures than the corresponding LSV in these two norms. What is more, the wave train structures of CNOP may even be found in the whole zonal direction in the Northern Hemisphere. The evolutions of perturbations, represented by CNOPs and LSVs in the total‐energy norm, are also investigated in detail. The similarities and dissimilarities between CNOPs and LSVs are revealed not only from the growth rate but also from the similarity index of spatial patterns.The numerical results imply that the method of CNOP may be a more appropriate tool for the study of stability and sensitivity problems when nonlinearity is of importance. Furthermore, the proper norm should be chosen for different physical problems. Copyright © 2008 Royal Meteorological Society
Observations of cross‐ridge flows across steep terrain
Authors: Lewis H. W. , Mobbs S. D. , Lehning M. 
Published: May 2008

AbstractA field experiment, Gaudex, has been conducted to address the need for quantitative measurements of turbulence in the vicinity of steep terrain. A dense network of automatic weather stations and turbulence towers was deployed along cross‐ridge transects over Gaudergrat, a steep triangular cross‐section ridge in eastern Switzerland.A new feature, whereby ridge‐normal cross‐ridge flows develop at the crest even when the flow in each valley is oriented parallel to the ridge axis, is identified. This occurs independently of whether the flow is thermally or synoptically driven. Pressure measurements across the ridge show that this flow is driven by a cross‐ridge pressure gradient. Two mechanisms for generating cross‐ridge flows have been identified from measurements of pressure, wind and temperature. In most cases the pressure gradient arises from a difference in flow speeds between the two sides of the ridge, caused by different valley geometries. Less commonly, the cross‐ridge flow is explained by linear speed‐up of the ridge‐normal flow. Copyright © 2008 Royal Meteorological Society
Coupled‐cluster approach to spontaneous symmetry breaking in molecules: The linear N3 radical
Authors: Li Xiangzhu , Paldus Josef 
Published: May 2008

AbstractSymmetry‐breaking phenomena that often affect calculation of potentials for the linear ABA species along the antisymmetric‐stretching coordinate are examined for the case of the ground state of the N3 radical using various coupled‐cluster methods and molecular orbitals. The difficulties that are encountered when employing UHF‐type approaches are found to be particularly striking. It is shown that the inconsistencies that arise when relying on a numerical differentiation can be overcome by exploiting the computed potentials in the Schrödinger equation for the nuclear motion. This approach yields reliable values for the vibrational levels even in the presence of singularities that plague the UHF‐based potentials. The variety of the symmetry‐breaking phenomena that occur for these systems, including the notoriously intricate BNB radical, are briefly discussed. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Sampling independent sets in the discrete torus
Authors: Galvin David 
Published: May 2008

AbstractThe even discrete torus is the graphTL,don vertex set {0,…,L– 1}d(withLeven) in which two vertices are adjacent if they differ on exactly one coordinate and differ by 1(modL) on that coordinate. The hard‐core measure with activity λ onTL,dis the probability distribution πλon the independent sets (sets of vertices spanning no edges) ofTL,din which an independent setIis chosen with probability proportional to λ|I|. This distribution occurs naturally in problems from statistical physics and the study of communication networks.We study Glauber dynamics, a single‐site update Markov chain on the set of independent sets ofTL,dwhose stationary distribution isπλ. We show that for λ = ω(d−1/4log3/4d) anddsufficiently large the convergence to stationarity is (essentially) exponentially slow inLd−1. This improves a result of Borgs, Chayes, Frieze, Kim, Tetali, Vigoda, and Vu (Proceedings of the IEEE FOCS (1999), 218–229)5who had shown slow mixing of Glauber dynamics for λ growing exponentially withd.Our proof, which extends to ρ‐local chains (chains which alter the state of at most a proportion ρ of the vertices in each step) for suitable ρ, closely follows the conductance argument of Borgs et al.,5adding to it some combinatorial enumeration methods that are modifications of those used by Galvin and Kahn (Combinatorics, Probability and Computing 13 (2004), 137–164)12to show that the hard‐core model with parameter λ on the integer lattice ℤdexhibits phase coexistence for λ =ω(d−1/4log3/4d).The discrete even torus is a bipartite graph, with partition classes ε (consisting of those vertices the sum of whose coordinates is even) and$$ \cal{O} $$. Our result can be expressed combinatorially as the statement that for each sufficiently large λ, there is a ρ(λ) > 0 such that ifIis an independent set chosen according toπλ, then the probability that ‖I∩ε|—|I∩$ \cal{O} $‖ is at most ρ(λ)Ldis exponentially small inLd−1. In particular, we obtain the combinatorial result that for all ε > 0 the probability that a uniformly chosen independent set fromTL,dsatisfies ‖I∩ε|—|I∩$ \cal{O} $‖≤ (.25 ‐ε)Ldis exponentially small inLd−1. © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2008
From the horse's mouth: What scientists say about scientific investigation and scientific knowledge
Authors: Wong Siu Ling , Hodson Derek 
Published: May 2008

AbstractThis study sought to identify prominent features of the nature of science (NOS) embedded in authentic scientific inquiry. Thirteen well‐established scientists from different parts of the world, working in experimental or theoretical research, in both traditional fields such as astrophysics and rapidly growing research fields such as molecular biology, completed an open‐ended questionnaire about the NOS and participated in in‐depth interviews. The descriptions of their practices provide a somewhat striking contrast to the image of science usually portrayed in science curricula and textbooks. These accounts of authentic scientific practice have considerable potential for development into interesting cases as teaching resources to enhance and enrich students' understanding of NOS and for the design of more effective laboratory work and field experience. © 2008 Wiley Periodicals, Inc. Sci Ed 93:109–130, 2009
Erratum: Shareholder valuation of foreign investment and expansion. Heather Berry. Strategic Management Journal, 27(12): 1123–1140 (2006)
Authors: Berry Heather 
Published: May 2008

AbstractHalf of the last sentence in the abstract was incorrectly deleted in the original publication of this
paper. The sentence should read as follows:"These results highlight the importance of considering firm location decisions, prior experiences and resources when analyzing the performance effects from multinationality by showing that shareholders value different paths to international expansion for firms that vary in these dimensions."
Serotoninergic dorsal raphe neurons possess functional postsynaptic nicotinic acetylcholine receptors
Authors: Galindo‐Charles Luis , Hernandez‐Lopez Salvador , Galarraga Elvira , Tapia Dagoberto , Bargas José , Garduño Julieta , Frías‐Dominguez Carmen , Drucker‐Colin René , Mihailescu Stefan 
Published: May 2008

AbstractVery few neurons in the telencephalon have been shown to express functional postsynaptic nicotinic acetylcholine receptors (nAChRs), among them, the noradrenergic and dopaminergic neurons. However, there is no evidence for postsynaptic nAChRs on serotonergic neurons. In this study, we asked if functional nAChRs are present in serotonergic (5‐HT) and nonserotonergic (non‐5‐HT) neurons of the dorsal raphe nucleus (DRN). In rat midbrain slices, field stimulation at the tegmental pedunculopontine (PPT) nucleus evoked postsynaptic currents (eEPSCs) with different components in DRN neurons. After blocking the glutamatergic and GABAergic components, the remaining eEPSCs were blocked by mecamylamine and reduced by either the selective α7 nAChR antagonist methyllycaconitine (MLA) or the selective α4β2 nAChR antagonist dihydro‐β‐eritroidine (DHβE). Simultaneous addition of MLA and DHβE blocked all eEPSCs. Integrity of the PPT‐DRN pathway was assessed by both anterograde biocytin tracing and antidromic stimulation from the DRN. Inward currents evoked by the direct application of acetylcholine (ACh), in the presence of atropine and tetrodotoxin, consisted of two kinetically different currents: one was blocked by MLA and the other by DHβE; in both 5‐HT and non‐5‐HT DR neurons. Analysis of spontaneous (sEPSCs) and evoked (eEPSCs) synaptic events led to the conclusion that nAChRs were located at the postsynaptic membrane. The possible implications of these newly described nAChRs in various physiological processes and behavioral events, such as the wake‐sleep cycle, are discussed. Synapse 62:601–615, 2008. © 2008 Wiley‐Liss, Inc.
The value of umbilical artery Doppler velocimetry in the antenatal surveillance of uncomplicated monochorionic twin pregnancies
Authors: Hack K. E. A. , Kaandorp J. J. , Derks J. B. , Elias S. G. , Pistorius L. , Visser G. H. A. 
Published: May 2008

AbstractObjectivesTo investigate the predictive value of abnormal umbilical artery Doppler findings on outcome in uncomplicated monochorionic (MC) twin pregnancies.MethodsSixty‐seven MC twin pregnancies, with antenatal care and delivery at the University Medical Center, Utrecht, The Netherlands, between 1999 and 2004, were studied. Pregnancies with antenatal signs of twin‐to‐twin transfusion syndrome were excluded. We analyzed the data according to both the last Doppler measurement of the umbilical artery before delivery and the presence of any abnormal Doppler measurement during the course of pregnancy. Risks of mortality and total neonatal morbidity were stratified according to the Doppler findings in one or both fetuses at the time of each standard ultrasound assessment in order to estimate the risk associated with an abnormal Doppler finding at or before that specific gestational age.ResultsMortality rates were similar in the normal and abnormal Doppler groups. Using both group definitions, total neonatal morbidity was higher in the abnormal Doppler group; this was significant at > 32 weeks' gestation, and was due to lower birth weight and earlier gestational age at delivery. There was no mortality at ≥ 36 weeks in the abnormal Doppler group, but there were four perinatal deaths in the normal Doppler group. Gestational age at delivery was significantly lower when one or more abnormal Doppler findings had been present (median, 34 + 1 weeks vs. 36 + 3 weeks) and infants with abnormal Doppler findings weighed on average 261 g (95% CI, 21–502g) less than those with normal findings.ConclusionsIn MC twins, abnormal Doppler flow of the umbilical artery identifies a subgroup at risk for preterm delivery, low birth weight and neonatal morbidity, but with a similar mortality risk to those with normal Doppler flow. At term, mortality occurred only in the group with normal Doppler findings, suggesting that fetal surveillance is insufficient in uncomplicated term MC twin pregnancies. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal assessment of the normal fetal soft palate by three‐dimensional ultrasound examination: is there an objective technique?
Authors: Faure J.‐M. , Bäumler M. , Boulot P. , Bigorre M. , Captier G. 
Published: May 2008

AbstractObjectivesTo describe a three‐dimensional (3D) ultrasound technique for assessing the fetal soft palate.MethodsA prospective study conducted from April to December 2006 included 87 fetuses in a low‐risk population. Fetal ultrasound scans were performed between 21 and 25 weeks of gestation to determine the normal 3D ultrasound view of the fetal soft tissues of the palate. The sonographers used a 30°‐inclined axial 3D view of the fetal palate. Ultrasound images obtained in this view were compared with fetopathological specimens of the same gestational age by two observers, both pediatric surgeons. Each observer indicated whether they thought that the uvula or the velum could be detected, and the differences in responses between the observers were assessed.ResultsThe frequencies of detection of the uvula and velum of each observer varied between 80% and 90%. The observers showed a significant difference in judging the visualization of the uvula, but not in judging the velum.ConclusionsA 30°‐inclined axial 3D ultrasound view seems to be effective in assessing the integrity of the fetal soft palate. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Quantitative elemental analysis of FeZn‐alloy coating by nondestructive method
Authors: Park Hyoungkuk , Lee Chong Soo 
Published: May 2008

AbstractA quantitative analytical method of iron content in FeZn‐alloy coating by x‐ray diffraction (XRD) spectrum was proposed. This work aimed to replace the wet chemical analysis of FeZn‐alloy coating with rapid and reproducible quantification by an XRD spectrum. Partial least‐squares (PLS) model was utilized to differentiate the spectral characteristic as well as to quantify each component in XRD spectrum. Fifteen standard samples were prepared by heat treatment and verified by the relationship between wet chemical analyses and the XRD spectrum for iron content. The suggested method showed satisfactory precision and accuracy in the analysis of FeZn‐alloy coating. The accuracy for iron content in FeZn‐alloy coating was 0.17 wt%. Copyright © 2008 John Wiley & Sons, Ltd.
Delayed union of an operated fracture of the femoral neck
Authors: Dhar Shabir Ahmed , Gani Naseem U. , Butt Mohammed F. , Farooq Munir , Mir Mohammed Ramzan 
Published: May 2008

Abstract
Fracture of the femoral neck continues to be a vexing clinical and therapeutic challenge for the orthopedic surgeon. The fracture has a propensity for non-union and avascular necrosis. It is a challenge for the orthopedic surgeon to decide when to intervene in a case with non-union where the implant continues to be in place. We present a case with persistent clinical and radiological non-union signs where the fracture eventually united after 32 months. The case bolsters the view that a continued conservative regime might entail good results in such situations.
Monogenetische Risikofaktoren einer Thrombophilie
Authors: Pavlova A. , Hertfelder H.-J. 
Published: May 2008

Zusammenfassung
Die hereditären Thrombophilien gehören zu den angeborenen Prädispositionen, die thrombotische Ereignisse begünstigen. Die wichtigsten monogenetischen Ursachen für einen venös-thromboembolischen (VTE) Phänotyp stellen Mutationen innerhalb der Gene für die Inhibitoren Antithrombin (AT), Protein C (PC) und Protein S (PS) dar. Die Mutationsprofile in diesen Genen sind sehr unterschiedlich. Die Frequenz von AT-, PC- und PS-Mängeln wird bei VTE-Patienten jeweils mit 1,9%, 2,3% und 3,7% angegeben. Die VTE-Rezidivrate liegt in dieser Gruppe bei etwa 48%. Sie ist für AT-, PC- und PS-Mängel zusammengefasst 1,5-fach, für den AT-Mangel isoliert betrachtet 1,9-fach höher als bei VTE-Patienten ohne einen dieser Mängel. Die Detektionsrate bei einem Inhibitormangel und VTE-Ereignis liegt bei etwa 70% für AT, bei 60% für PC und bei 30% für PS. Dies unterstreicht das Problem der unterschiedlichen Sicherheit der Diagnose der Phänotypen und der damit zusammenhängenden differentialdiagnostischen Abgrenzung zwischen erworbenem und angeborenem Inhibitormangel.
Intake of B vitamins in childhood and adult life in relation to psychological distress among women in a British birth cohort
Authors: Mishra Gita D , McNaughton Sarah A , O’Connell Maria A , Prynne Celia J , Kuh Diana 
Published: May 2008

AbstractBackgroundLower levels of B vitamins (particularly folate, vitamin B12and vitamin B6) may be associated with psychological distress. Little is known about the impact of childhood nutrition on psychological distress in adult life.ObjectiveWe investigated whether prospectively measured childhood and adult dietary intakes of thiamin, riboflavin, niacin, folate, vitamin B6and vitamin B12were related to the psychological distress of women in mid-age, taking into account socio-economic, behavioural and lifestyle factors.DesignProspective data were collected from a cohort of 636 British women followed up since their birth in 1946. Participants completed a 28-item, scaled version of the General Health Questionnaire (GHQ-28) to measure psychological distress at age 53 years. Dietary intakes in childhood (at age four) were determined by 24h recall and in adulthood (at age 36, 43 and 53 years) by a 5d food record.ResultsLow dietary vitamin B12intake at age 53 was associated with higher psychological distress at that age. Women in the lowest third of vitamin B12intake in adulthood had a higher GHQ-28 score compared with those in the highest third (percentage change, adjusted regression coefficient, 21 (95% CI 3, 39)). There were no other significant associations between dietary B vitamin intake in childhood or adulthood and psychological distress in the cohort.ConclusionsOverall, there is evidence that intake of vitamin B12at age 53 is related to adult psychological distress but there is no evidence for the effects of other adult B vitamin intakes or childhood intakes on psychological distress.
Longitudinal growth of infants born to HIV-1-infected mothers in Belo Horizonte, Brazil
Authors: Fausto Maria Arlene , Carneiro Mariângela , Antunes Carlos Maurício F , Colosimo Enrico Antônio , Pinto Jorge A 
Published: May 2008

AbstractObjectiveTo prospectively evaluate growth parameters assessed by weight and length in infected and uninfected infants born to HIV-1-infected mothers and followed from birth to 18 months.MethodsA cohort consisting of ninety-seven uninfected and forty-two infected infants born to HIV-infected mothers enrolled from 1995 to 2004, and admitted during their first 3 months of life at a referral Pediatric AIDS Clinic in Belo Horizonte, Brazil. Infants were followed until 18 months of age. Data were analysed using mixed-effects linear regression models for weight and length fitted by restricted maximum likelihood.ResultsInfected infants contributed to 466 weight and 411 recumbent length measurements. Uninfected infants provided 924 weight and 907 length measurements. Mean birth weight and length were similar in both groups, 3·1 (sd 0·4) and 3·0 (sd 0·5) kg, and 48·7 (sd 1·4) and 48·8 (sd 2·9) cm for uninfected and infected infants, respectively. However, HIV-1 infection had an early impact in growth impairment: at 6 months of age, HIV-infected children were 1 kg lighter and 2 cm shorter than the uninfected.ConclusionsGrowth faltering in weight, but not length, in HIV-infected children in Brazil is more marked than that reported in a European cohort, probably reflecting background nutritional deficiencies and concomitant infections. In these settings, early and aggressive nutritional management in HIV-1-infected infants should be a priority intervention associated with the antiretroviral therapy.