bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three‐dimensional multiplanar time‐motion ultrasound or anatomical M‐mode of the fetal heart: a new technique in fetal echocardiography
Authors: Jürgens J. , Chaoui R. 
Published: March 2003

AbstractObjectiveTo assess the application of a three‐dimensional multiplanar rendering technique for examination of the fetal heart.Material and MethodsFree‐hand acquisition of a three‐dimensional volume was performed without moving or tilting the transducer. While the anatomical plane shows the four cardiac chambers, the two other orthogonal planes show vertical and horizontal time‐axis planes as M‐mode traces. Because off‐line plane positioning is possible on three‐dimensional multiplanar reconstruction, M‐mode traces can be obtained from different stored cardiac structures independently of the fetal position. Fifty‐two women with normal singleton pregnancies at 22–40 weeks underwent transabdominal ultrasound examination and five women with singleton fetuses between 13 and 15 weeks were assessed transvaginally. Clinical application of the echocardiographic technique was tested in a further two fetuses with arrhythmia.ResultsOff‐line M‐mode traces from atrioventricular valve excursions and myocardial contractions were possible in 45/52 (86.5%) cases examined at 22–40 weeks. Among the 32 fetuses in which visualization of the outflow tracts was attempted, M‐mode traces of the aortic and pulmonary valves were possible in 22 (68.7%) and 20 (62.5%) cases, respectively. In three of five cases examined transvaginally, M‐mode traces could be registered. Both cases with supraventricular extrasystoles (26 and 31 weeks) were easily diagnosed using this technique.ConclusionThe new technique presented here enables the easy acquisition of optimal M‐mode traces from different fetal heart structures. Based on our promising findings we would recommend that, in the future, three‐dimensional multiplanar imaging should not be limited to automatic volume acquisition but should include the free‐hand technique. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Adaptive space decomposition for fast visualization of soft objects
Authors: Min KyungHa , Lee In‐Kwon , Park Chan‐Mo 
Published: March 2003

AbstractWe present a fast visualization scheme of soft objects by introducing an efficient evaluation method for a field function. The evaluation of a field function includes distance computation between a point in space and the defining primitives of the soft object. If the unnecessary distance computations between a point in space and the components that do not influence the point can be avoided, the evaluation can be accelerated. For this purpose, we decompose the space into adaptive‐sized cells according to the bounding volume of the components and build a data structure called an interval tree through which the influencing components for a point are sought. The bounding volume of a component is generated by considering the radius of a component and k‐DOPs. The proposed scheme can be used in many applications for soft objects such as modeling and rendering, especially in the interactive modeling process. Copyright © 2003 John Wiley & Sons, Ltd.
Reliability‐based Design Methods to Determine the Extreme Response Distribution of Offshore Wind Turbines
Authors: Cheng P. W. , van Bussel G. J. W. , van Kuik G. A. M. , Vugts J. H. 
Published: March 2003

AbstractIn this article a reliability‐based approach to determine the extreme response distribution of offshore wind turbines is presented. Based on hindcast data, the statistical description of the offshore environment is formulated. The contour lines of different return periods can be determined. Simulations are carried out for a prototype design of a 3 MW offshore wind turbine. Statistical methods are applied to determine the distribution of the extreme responses. Three approaches are used here. In the MAX approach, only the maximum of each simulation is taken into account. The POT (peak over threshold) approach takes also local maxima into consideration. The process model uses the statistical properties of the process to predict the extremes. All three methods show similar results, but POT and the process model require fewer simulations. Comparison is made for the 100 year response between these reliability‐based models and a deterministic model. For this specific turbine the deterministic model underestimates the maximum flap moment but overestimates the maximum overturning moment of the support structure compared with the estimates of the reliability‐based methods. The application of the reliability‐based model can be extended to include other extreme load situations and achieve a more efficient structural design. Copyright © 2003 John Wiley & Sons, Ltd.
Estimating Wind Energy Potential Offshore in Mediterranean Areas
Authors: Lavagnini Alfredo , Sempreviva Anna M. , Barthelmie Rebecca J. 
Published: March 2003

AbstractRelatively few studies have been performed on the evaluation of offshore wind resources, and these have been conducted mostly in Northern Europe. In Mediterranean areas the lack of such studies is mainly linked to (1) the difficulty of meteorological monitoring in deeper waters, (2) the complex orography, frequently extending down to the coasts, (3) the sea breeze wind regimes and (4) local winds such as the Bora, Mistral and Sciroc. In the North Adriatic Sea, a shallow basin of the Mediterranean, the first reason is not applicable, but the others are sufficient to make the evaluation of wind speed methods challenging. In this article we estimate the wind climatology at a platform located 15 km offshore of Venice based on 7 years of data and compare it with the wind climatology obtained by five different methods using the long‐term data from four coastal meteorological stations, Venezia Tessera, Venezia San Nicolò, Ronchi and Rimini. We discuss the applicability of these methods and find that the WAsP® model of Risø National Laboratory is still the best tool for wind climate estimates. The results of two new methods are promising, but the methods still require some development. Copyright © 2003 John Wiley & Sons, Ltd.
On the Modelling of a Floating Offshore Wind Turbine
Authors: Henderson Andrew R. , Patel Minoo H. 
Published: March 2003

AbstractThe location of wind turbines on floating structures offshore would allow an immense resource to be tapped without the drawbacks large developments can have on public opinion. There are, however, potentially significant technical and cost drawbacks. This article describes the theory and results of research work aimed at developing analytical tools for evaluating the performance of floating offshore wind farms. The principal problem addressed here is the development of analytical tools for modelling the turbine loads and fatigue damage due to the vessel motion. The effect that the motion would have on the wind turbine is found by calculating the aerodynamic and inertial loads on the blades in a two‐dimensional state domain representing the blade and the vessel motion respectively. Using a double Fourier transform, discrete deterministic frequency spectra of the loads are found and the fatigue damage is evaluated. Undertaking the calculations for vessel motion in each degree of freedom allows appropriate weightings to be developed, which can be used for the optimization of candidate supporting vessels by evaluating the motion response directly. Copyright © 2003 John Wiley & Sons, Ltd.
Die Kristallstruktur von wasserfreiem Melaminiumchlorid
Authors: Jing Haipeng , Ströbele Markus , Weisser Martina , Meyer H.‐Jürgen 
Published: March 2003

Crystal Structure of non‐aqueous Melaminium ChlorideMelaminium chloride was obtained as colorless, needle‐shaped, single crystalline material from solid state reactions between melamin and ammonium chloride. The structure of [C3N6H7]Cl was refined by single crystal X‐ray diffraction: I2/m, Z = 8, a = 852.87(4), b = 1704.4(1) c = 918.44(4) pm and β = 92.165(6)°. The crystal structure contains melaminium ions stacked to columns along [100] and linked via N‐H···N bridges to form bands along [001]. Both of the two distinct chloride ions are stabilized by six hydrogen bonds through distorted trigonal prismatic arrangements of hydrogen atoms to yield a supramolecular structure.
The Crystal Structure of ζ2‐Al3Cu4‐δ
Authors: Gulay L. D. , Harbrecht Bernd 
Published: March 2003

AbstractThe crystal structure of the ζ2‐phase Al3Cu4‐δ was determined by means of X‐ray powder diffraction: a = 409.72(1) pm, b = 703.13(2) pm, c = 997.93(3) pm, space group Imm2, Pearson symbol oI24‐3.5, RI = 0.0696. ζ2‐Al3Cu4‐δ forms a distinctive a × √3a × 2c superstructure of a metal deficient Ni2In‐type‐related structure. The phase is meta‐stable at ambient temperature. Between 400 °C and 450 °C it decomposes into ζ1‐Al3Cu4 and η2‐AlCu. Entropic contributions to the stability of ζ2‐Al3Cu4‐δ are reflected in three statistically or partially occupied sites.
Miscibility Gap in the System Cesium Amide/Ammonia, CsNH2/NH3 — Thermodynamic Investigations
Authors: Peters Dieter , Jacobs Herbert 
Published: March 2003

AbstractThe system CsNH2/NH3 is investigated between —50 °C and 120 °C: Partial pressures of ammonia, DTA and density measurements are given as a function of concentration and temperature.Thermodynamic interpretations of the data show that the solutions deviate strongly from the behaviour of ideal mixtures. A monoammoniate of CsNH2 is stable up to 17 °C. Dilute solutions (≤ 30 mole % CsNH2) have a miscibility gap above 79 ± 5 °C with an almost colourless solution of lower density clearly separated from a yellow one.Phase separation is discussed on the basis of hydrogen bonds between NH ions as acceptors and NH3 molecules both solvating cesium ions.
Sr3(BS3)2 und Sr3(B3S6)2: Zwei neue nicht‐oxidische Chalkogenoborate mit trigonal‐planar koordiniertem Bor
Authors: Hammerschmidt A. , Döch M. , Püttmann C. , Krebs B. 
Published: March 2003

AbstractSystematische Studien zur Synthese neuer Erdalkalimetallthioborate und zum Kationeneinfluß auf die Strukturen ternärer Verbindungen dieses Typs führten zu den Strontiumthioboraten Sr3(BS3)2 und Sr3(B3S6)2. Die neuen Verbindungen wurden aus Strontiumsulfid, amorphem Bor und Schwefel in Festkörperreaktionen bei einer Temperatur von 1123 K dargestellt. Die Kristallstrukturen wurden durch Röntgenstrukturanalysen an Einkristallen bestimmt. Sr3(BS3)2 kristallisiert in der monoklinen Raumgruppe C2/c (Nr. 15) mit a = 10, 187(4) Å, b = 6, 610(2) Å, c = 15, 411(7) Å, β = 102, 24(3)° und Z = 4. Die Kristallstruktur von Sr3(B3S6)2 ist trigonal, Raumgruppe R3¯ (Nr. 148), mit a = 8, 605(1) Å, c = 21, 542(4) Å und Z = 3. Sr3(BS3)2 enthält isolierte [BS3]3—‐Anionen mit Bor in trigonal‐planarer Koordination. Die Strontiumkationen befinden sich zwischen Schichten von Orthothioborat‐Anionen. Im Sr3(B3S6)2 liegen neben Strontiumkationen [B3S6]3—‐Anionen vor.
CoSm(SeO3)2Cl, CuGd(SeO3)2Cl, MnSm(SeO3)2Cl, CuGd2(SeO3)4 und CuSm2(SeO3)4: Übergangsmetallhaltige Selenite von Samarium und Gadolinum
Authors: Wickleder Mathias S. , Hamida Makram Ben 
Published: March 2003

AbstractBei der Umsetzung von CoCl2, Sm2O3 und SeO2 in evakuierten Quarzglasampullen bilden sich blaue Einkristalle von CoSm(SeO3)2Cl (triklin, ${\rm P} \bar 1$, Z = 4, a = 712, 3(1), b = 889, 5(2), c = 1216, 2(2) pm, α = 72, 25(1)°, β = 71, 27(1)°, γ = 72, 08(1)°, Rall = 0, 0586). Beim Umsatz mit MnCl2 werden blaßrosa Einkristalle von MnSm(SeO3)2Cl erhalten (triklin, ${\rm P} \bar 1$, Z = 2, a = 700, 8(2), b = 724, 1(2), c = 803, 4(2) pm, α = 86, 90(3)°, β = 71, 57(3)°, γ = 64, 33(3)°, Rall = 0, 0875). Lindgrüne Einkristalle von CuGd(SeO3)2Cl (triklin, ${\rm P} \bar 1$, Z = 4, a = 704, 3(4), b = 909, 6(4), c = 1201, 0(7) pm, α = 70, 84(4)°, β = 73, 01(4)°, γ = 70, 69(4)°, Rall = 0, 0450) bilden sich bei der Reaktion von CuCl2 und Gd2O3 mit SeO2. In CoSm(SeO3)2Cl liegen [CoO4Cl2]‐Oktaeder vor, die über eine Kante und eine Ecke zu Ketten verknüpft sind. Auch die Mn2+‐Ionen in MnSm(SeO3)2Cl sind oktaedrisch von vier Sauerstoff‐ und zwei Chloridliganden umgeben. Die Verknüpfung der Polyeder erfolgt zu Ketten erfolgt hier jedoch ausschließlich über Kanten. Sowohl in der Cobalt‐ als auch in der Mangan‐Verbindung sind die Sm3+‐Ionen acht‐ bzw. neunfach von Sauerstoffatomen und Chloridionen umgeben. In CuGd(SeO3)2Cl sind die Cu2+‐Ionen verzerrt quadratisch‐planar von drei Sauerstoffatomen und einem Chloridion umgeben. Ein weiterer Cl—‐ bzw. Sauerstoffligand ergänzen die [CuO3Cl]‐Einheiten zu stark elongierten Oktaedern. Letztere sind wiederum über zwei Kanten zu Ketten verknüpft. Den Gd3+‐Ionen kommen die Koordinationzahlen „8 + 1”︁ bzw. neun zu. Werden die Oxide Sm2O3 bzw. Gd2O3 mit CuO und SeO2 umgesetzt, bilden sich die tiefblauen Selenite CuM2(SeO3)4 (M = Sm/Gd, monoklin, P21/c, Z = 2, a = 1050, 4(3)/1051, 0(2), b = 696, 6(2)/693, 5(1), c = 822, 5(2)/818, 5(2) pm, β = 110, 48(2)°/110, 53(2)°, Rall = 0, 0341/0, 0531). Beide enthalten isolierte quadratisch‐planare [CuO4]‐Gruppen und unregelmäßige [MO9]‐Polyeder.
(CuBr)3P4Se4: A Low Symmetric Variant of the (CuI)3P4Se4 Structure Type
Authors: Reiser Sara , Nilges Tom , Pfitzner Arno 
Published: March 2003

AbstractBright orange (CuBr)3P4Se4 is obtained from the reaction of CuBr, P, and Se in stoichiometric amounts (CuBr : P : Se = 3 : 4 : 4). The composition and the crystal structure of the compound were determined from single crystal X‐ray diffraction data. Lattice constants are a = 33.627(2) Å, b = 6.402(1) Å, c = 19.059(1) Å, β = 90.19(3) °, V = 4103.2(3) Å3, and Z = 12. The compound crystallizes in a structure that is related to (CuI)3P4Se4. Cages of β‐P4Se4 are stacked along the b‐axis and are separated by columns of copper(I) bromide. However, the coordination of the β‐P4Se4 cage molecules to the copper atoms in the CuBr columns in (CuBr)3P4Se4 is quite different from (CuI)3P4Se4. The monoclinic compound (space group: P21, no. 4) has an almost orthorhombic metric in combination with a threefold superstructure in [100]. Structural aspects of (CuBr)3P4Se4 are discussed with respect to the heavier homologue (CuI)3P4Se4.
SYMMETRY BREAKING EFFECTS ON EQUILIBRIA AND TIME DEPENDENT REGIMES IN ADAPTIVE LOTKA–VOLTERRA SYSTEMS
Authors: LACITIGNOLA DEBORAH , TEBALDI CLAUDIO 
Published: March 2003

We study the properties of a n2-dimensional Lotka–Volterra system describing competition among n different species with adaptive skills, i.e. whose interaction coefficients are time averages of the species level of interaction over their past.Starting by the case of adaptive competition among species all having the same carrying capacities, we focus our attention on the model obtained on perturbing the carrying capacity of a fixed species, which is made more or less disadvantaged.We prove the existence of a certain class of invariant subspaces and introduce a seven-dimensional reduced model, where n appears as a parameter, which gives full account of existence and stability of equilibria in the system. The relevance of this reduced model to the complete one has also been found when the time dependent regimes have been investigated.Ecologically relevant questions, i.e. species survival and the time dependent behavior of the system have also been analyzed focusing on the role of behavioral adaptation. In particular, we have found that competitive exclusion cannot occur but coexistence is possible in various forms (i.e. competitive stable equilibria and different periodic oscillations).
Telecommunications and Travel: The Case for Complementarity
Authors: Mokhtarian Patricia L. 
Published: March 2003

SummaryThis article examines the conceptual, theoretical, and empirical evidence with respect to the impact of telecommunications on travel. The primary focus is on passenger travel, but goods movement is addressed briefly. I argue that although direct, short‐term studies focusing on a single application (such as telecommuting) have often found substitution effects, such studies are likely to miss the more subtle, indirect, and longer‐term complementarity effects that are typically observed in more comprehensive analyses. Overall, substitution, complementarity, modification, and neutrality within and across communication modes are all happening simultaneously. The net outcome of these partially counteracting effects, if current trends continue, is likely to be faster growth in telecommunications than in travel, resulting in an increasing share of interactions falling to telecommunications, but with continued growth in travel in absolute terms. The empirical evidence to date is quite limited in its ability to assess the extent of true causality between telecommunications and travel, and more research is needed in that area. At this point, what we can say with confidence is that the empirical evidence for net complementarity is substantial, although not definitive, and the empirical evidence for net substitution appears to be virtually nonexistent.
Effects of E‐Commerce on Greenhouse Gas Emissions: A Case Study of Grocery Home Delivery in Finland
Authors: Siikavirta Hanne , Punakivi Mikko , Kärkkäinen Mikko , Linnanen Lassi 
Published: March 2003

SummaryIn this article, we present a literature review of the general and environmental effects of e‐commerce in various parts of the demand‐supply chain. These are further translated into effects on greenhouse gas (GHG) emissions in the food production and consumption system. The literature study revealed many opportunities for e‐commerce to reduce GHG emissions in the food production and consumption system. Some possibly negative effects were also identified. Electronic grocery shopping (e‐grocery) home delivery service was chosen as the subject of a case study because of its direct and indirect potential for reducing the GHG emissions in the food production and consumption system.GHG emission reduction potential through the implementation of various e‐grocery home delivery strategies was quantified. Depending on the home delivery model used, it is possible to reduce the GHG emissions generated by grocery shopping by 18% to 87% compared with the situation in which household members go to the store themselves. We estimate that the maximum theoretical potential of e‐grocery home delivery service for reducing the GHG emissions of Finland is roughly 0.3% to 1.3%; however, the current and estimated future market potential is much smaller, because the estimated market share of e‐grocery services is only 10% by 2005. Narrowing the gap between the theoretical and the actual potential requires a model that would simultaneously provide additional value to the consumer and be profitable to companies. To be able to achieve significant reductions in GHG emissions, system‐level innovations and changes are required. Further research is needed before conclusions can be reached as to whether e‐commerce and e‐grocery are useful tools in that respect.
Human reconstituting hematopoietic stem cells up-regulate Fas expression upon active cell cycling but remain resistant to Fas-induced suppression
Authors: Dybedal Ingunn , Yang Liping , Bryder David , Aastrand-Grundstrom Ingbritt , Leandersson Karin , Jacobsen Sten Eirik W. 
Published: March 2003

Abstract
The Fas receptor and its ligand have been implicated in mediating the bone marrow (BM) suppression observed in graft-versus-host disease and a number of other BM-failure syndromes. However, previous studies have suggested that Fas is probably not expressed on human hematopoietic stem cells (HSCs), but up-regulated as a consequence of their commitment and differentiation, suggesting that progenitors or differentiated blood cells, rather than HSCs, are the targets of Fas-mediated suppression. The present studies confirm that candidate HSCs in human cord blood and BM lack constitutive expression of Fas, but demonstrate that Fas expression on CD34+ progenitor and stem cells is correlated to their cell cycle and activation status. With the use of recently developed in vitro conditions promoting HSC self-renewing divisions, Fas was up-regulated on virtually all HSCs capable of multilineage reconstituting nonobese diabetic/severe combined immunodeficiency (NOD-SCID) mice in vivo, as well as on long-term culture-initiating cells (LTC-ICs). Similarly, in vivo cycling of NOD-SCID repopulating cells upon transplantation, resulted in up-regulation of Fas expression. However, repopulating HSCs expressing high levels of Fas remained highly resistant to Fas-mediated suppression, and HSC function was compromised only upon coactivation with tumor necrosis factor. Thus, reconstituting human HSCs up-regulate Fas expression upon active cycling, demonstrating that HSCs could be targets for Fas-mediated BM suppression. (Blood. 2003;102: 118-126)
Gene expression analysis of purified hematopoietic stem cells and committed progenitors
Authors: Terskikh Alexey V. , Miyamoto Toshihiro , Chang Cynthia , Diatchenko Luda , Weissman Irving L. 
Published: March 2003

Abstract
Lifelong self-renewal is a unique property of somatic stem cells. Recently, several primitive multipotent yet committed (non—self-renewing) hematopoietic progenitor populations were identified in mouse bone marrow. We have characterized the expression of 1200 selected mouse genes using the Atlas cDNA array in highly purified hematopoietic stem cells (HSCs) and 6 closely related progenitor populations: common myeloid progenitors (CMPs), granulocyte-macrophage progenitors (GMPs), megakaryocyte-erythrocyte progenitors (MEPs), common lymphoid progenitors (CLPs), and pro-T and pro-B cells. Cluster analysis revealed that nearly half of all differentially expressed transcripts are associated with HSCs, supporting the notion of an active transcriptional status of HSCs. Genes found enriched in the HSC cluster encompass many developmentally regulated genes, some previously associated with HSC self-renewal. In contrast, genes that are enriched in committed progenitors are mostly associated with hematopoietic differentiation, immune regulation, and metabolism. Thus, the transition from HSCs toward committed progenitors correlates with the down-regulation of a large number of HSC-associated genes and progressive up-regulation of a limited number of lineage-specific genes. These genetic analyses revealed both quantitative and qualitative differences between the transcripts associated with HSCs versus downstream progenitors and produced a list of the candidate genes, potentially involved in HSC self-renewal. (Blood. 2003;102:94-101)