bluuebunny/crossref_metadata_2025 huggingface dataset:
A local branching heuristic for mixed‐integer programs with 2‐level variables, with an application to a telecommunication network design problem
Authors: Fischetti Matteo , Polo Carlo , Scantamburlo Massimo
Published: July 2004

Effective heuristic solution methods for general Mixed‐Integer Programs (MIPs) are strongly required in many practical applications, and have been the subject of an intensive research effort in the recent years. Fischetti and Lodi recently proposed an exact solution technique based on the use of branching conditions expressed through (invalid) linear inequalities called local branching cuts. In the concluding remarks of their article, these authors anticipated the possibility their method be used to design a genuine MIP metaheuristic framework akin to Tabu Search (TS) or Variable Neighborhood Search (VNS), based on an external MIP solver. In the present article we introduce and analyze computationally a specific implementation of the above idea. In particular, we address MIPs with binary variables, and propose a variant of the classical VNS scheme that we call Diversification, Refining, and Tight‐refining (DRT). The new approach is intended to be of high generality, but exploits the specific structure of some MIPs where the set of binary variables partitions naturally into two levels, with the property that fixing the value of the first‐level variables produces an easier‐to‐solve (but still hard) subproblem. This is often the case, for example, in hard facility location problems arising in telecommunication network design. Our method detects automatically the presence in the MIP model of the first‐level binary variables, if any, according to simple heuristic criteria. This information is then exploited during the intensification phase of the local search, so as to explore nested solution neighborhoods defined by local branching cuts affecting the first‐ and second‐level variables in a different way. Computational results for a hard facility location problem arising in telecommunication UMTS network design are presented, with a comparison among different heuristic methods: the general‐purpose commercial ILOG‐Cplex 7.0 MIP code, the original Fischetti‐Lodi local branching heuristic scheme, the new DRT method, and (for some instances) ad hoc TS and VNS heuristics. The results show that the DRT method, though very simple to implement, provides better heuristic solutions than the alternative methods on all the instances of our test bed. © 2004 Wiley Periodicals, Inc. NETWORKS, Vol. 44(2), 61–72 2004
On the impact of the solution representation for the Internet Protocol Network Design Problem with max‐hop constraints
Authors: De Giovanni L. , Croce F. Della , Tadei R.
Published: July 2004

The IP (Internet Protocol) Network Design Problem can be shortly stated as follows. Given a set of nodes and a set of traffic demands, we want to determine the minimum cost capacity installation such that all the traffic is routed. Capacity is provided by means of links of a given capacity and traffic must be loaded on the network according to the OSPF‐ECM (Open Shortest Path First—Equal Commodity Multiflow) protocol, with additional constraints on the maximum number of hops. The problem is strongly NP‐Hard, and the literature proposes local search‐based heuristics that do not take into account max‐hop constraints, or assume a simplified OSPF routing. The core in a local search approach is the network loading algorithm for the evaluation of the neighbor solutions costs. It presents critical aspects concerning both computational efficiency and memory requirements. Starting from a tabu search prototype, we show how these aspects deeply impact on the design of a local search procedure, even at the logical level. We present several properties of the related network loading problem, that allow to overcome the critical issues and lead to an efficient solution evaluation. © 2004 Wiley Periodicals, Inc. NETWORKS, VoL. 44(2), 73–83 2004
Grid scheduling by on‐line rectangle packing
Authors: Caramia Massimiliano , Giordani Stefano , Iovanella Antonio
Published: July 2004

The Grid computing paradigm is originated from a new computing infrastructure for scientific research and cooperation, and is becoming an established technology for large‐scale resource sharing and distributed integration. Two main problems arise: how to efficiently allocate resources to tasks and, after this, how to schedule them. In this article we propose to solve the scheduling phase by means of rectangle packing algorithms. In particular, two on‐line rectangle packing algorithms are proposed with the objective of maximizing the system efficiency. A wide computational analysis is provided. The performances of the proposed algorithms are first compared with those of known algorithms on benchmark instances for rectangle packing, and then are evaluated on different Grid scheduling scenarios associated with different processing and dataset environments. © 2004 Wiley Periodicals, Inc. NETWORKS, Vol.44(2), 106–119 2004
Predictors of patient satisfaction with inpatient hospital nursing care
Authors: Larrabee June H. , Ostrow C. Lynne , Withrow Mary Lynne , Janney Michelle A. , Hobbs Gerald R. , Burant Christopher
Published: July 2004

The purpose of this predictive nonexperimental study was to investigate the influence of registered nurse (RN) job satisfaction, context of care, structure of care, patient‐perceived nurse caring, and patient characteristics on patient satisfaction with inpatient hospital nursing care in an academic medical center in north‐central West Virginia. Convenience samples of patients (N = 362) and RNs (N = 90) were recruited from two medical units, two surgical units, and three intensive care step‐down units. Causal modeling identified patient‐perceived nurse caring as the major predictor of patient satisfaction, with nurse/physician (RN/MD) collaboration as the only other direct predictor. Age had an indirect influence on patient satisfaction. Strategies to achieve and maintain patient satisfaction should address the enhancement of patient‐perceived nurse caring and RN/MD collaboration. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:254–268, 2004
Effectiveness of a videotape for sexual counseling after myocardial infarction
Authors: Steinke Elaine E. , Swan James H.
Published: July 2004

A two‐group randomized clinical trial was used to test the hypothesis that patients with myocardial infarction (MI) who receive both written instructions and a videotape to view at home will have greater knowledge, better quality of life, less anxiety, greater sexual satisfaction, and will resume sexual activity more quickly than will those who receive written instructions alone. The participants, 115 patients diagnosed with an MI, were pretested in the hospital and followed at home at 1, 3, and 5 months. The intervention was an educational videotape on return to sexual activity. Significant improvements in knowledge were found for the experimental group at 1 month. The videotape intervention provides an alternative method for education to facilitate recovery post‐MI. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:269–280, 2004
Patterns and predictors of sleep pattern disturbance after cardiac surgery
Authors: Redeker Nancy S. , Ruggiero Jeanne , Hedges Christine
Published: July 2004

The purposes of this study were to examine changes in sleep patterns after cardiac surgery and the contributions of preoperative sleep to postoperative sleep. Seventy‐two cardiac surgery patients wore wrist actigraphs for 3 days during the preoperative period (T1) and the 1st (T2), 4th (T3), and 8th (T4) postoperative weeks. They completed the Pittsburgh Sleep Quality Index at T1, T3, and T4. Sleep was most disturbed during the 1st postoperative week and improved at T3 and T4. Overall, sleep pattern disturbance was higher at T3 and T4 than at T1. Age, gender, preoperative New York Heart Association Functional Class, and preoperative sleep variables explained 20%–50% of the variance in sleep at T2, T3, and T4. Sleep disturbance is present preoperatively and continues during the postoperative period. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:217–224, 2004
Cigarette smoking: Evidence to guide measurement
Authors: Stevens Kathleen R. , Muñoz Laura R.
Published: July 2004

Smoking cessation programs measure outcomes in terms of abstinence from or reduction in smoking. These outcomes can be measured through self‐report by the smoker, through measurement with a biological marker of smoking, or through a combination of both. Consideration of the relative advantages of self‐report and biomarker approaches is important in the selection of measurement strategies to evaluate outcomes in smoking cessation interventions. In this article both ways of measuring smoking behavior, self‐report and biomarkers of carbon monoxide, cotinine, nicotine, thiocyanate, and alkaloids of nicotine, are explored. Measurement approaches are discussed in light of research evidence and their physiologic bases. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:281–292, 2004
Variations in sleep hygiene practices of women with and without insomnia
Authors: Cheek Rita E. , Shaver Joan L. F. , Lentz Martha J.
Published: July 2004

Sleep hygiene education is a basic component of behavioral treatment for chronic insomnia, yet the actual sleep hygiene practices of people with insomnia have not been well documented. In this descriptive secondary analysis, midlife women ages 41–55 years with either chronic insomnia (n = 92) or good sleep (n = 29) kept diaries of sleep perceptions and sleep hygiene practices during 6 nights of somnographic monitoring at home. In both groups few reported smoking cigarettes (<10%), most drank caffeine (>80%), and many averaged 30 min of exercise per day (∼50%). Very few in either group (<10%) had regular (<30 min variation) bedtimes or getting‐up times. Compared to women with good sleep, those with insomnia reported drinking less caffeine per day, being more abstinent from alcohol, and having smaller variations in day‐to‐day alcohol intake and bedtimes. Although some women with insomnia limit or refrain from caffeine and alcohol intake, many have not optimized behaviors believed to help prevent or modulate insomnia. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:225–236, 2004
Adolescents' coping with surgery for scoliosis: Effects on recovery outcomes over time
Authors: LaMontagne Lynda L. , Hepworth Joseph T. , Cohen Frances , Salisbury Michele H.
Published: July 2004

Surgery for adolescent idiopathic scoliosis is painful and stressful and has a long and demanding recovery. The purpose of this study was to examine pre‐ and postoperative avoidant/vigilant coping and long‐term activity outcomes through 9 months postsurgery for adolescents (11–18 years, N = 113) undergoing scoliosis surgery. Generally, more vigilant copers (preoperatively and 1 month postoperatively) participated in more activities (usual, new, and social) and had higher academic performance during recovery. Several moderation effects indicated these relationships were stronger for older adolescents and those more internal in locus of control. Adolescents were more vigilant in the hospital, became more avoidant 1 month after surgery, and remained at these levels 6 months postsurgery. Understanding coping processes and individual factors is necessary to develop interventions to help adolescents cope successfully with recovery demands. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:237–253, 2004
Calculation of NMR parameters in van der Waals complexes involving organic systems and xenon
Authors: Bagno Alessandro , Saielli Giacomo
Published: July 2004

Some of our recent results concerning the prediction of NMR parameters for van der Waals (vdW) complexes are reviewed. Through‐space coupling constants, in organic molecules stabilized by CH–π interaction, are calculated to be of the order of 0.3 Hz, therefore above the current experimental resolution. Through‐space coupling constants between hydrocarbons and xenon are also calculated to be relatively large, of the order of a few Hz at the vdW contact distance. Finally, we present some preliminary data on the dependence of the chemical shift of xenon in vdW complexes with alkyl chains. These results will serve as a tool in molecular dynamics simulations of xenon dissolved in membranes. Copyright © 2004 John Wiley & Sons, Ltd.
Restricted rotation/tautomeric equilibrium and determination of the site and extent of protonation in bi‐imidazole nucleosides by multinuclear NMR and GIAO‐DFT calculations
Authors: Mäki Jukka , Tähtinen Petri , Kronberg Leif , Klika Karel D.
Published: July 2004

The restricted rotation about the conjoining bond in a series of 4″‐substituted bi‐imidazole nucleosides {5‐amino‐4‐[4″‐R‐imidazol‐2″‐yl]‐1‐(β‐d‐ribofuranosyl)‐1H‐imidazole; where R=H, methyl, hydroxymethyl, oxalo, formyl} due to intramolecular hydrogen bonding between N‐3″ and the N‐6 protons concomitant with prototropic tautomerism has been examined using multinuclear (1H, 13C and 15N) experimental NMR. Substitution at the 4″ position causes the interconversion, whilst still an intramolecular process, to yield complex spectra as the dynamic process consists of a two‐site exchange between non‐degenerate tautomeric forms (asymmetric sites). The preferred tautomers were identified experimentally in each case and compared with theoretically determined structures geometry optimized using density functional theory (DFT) at the B3LYP/6–31G(d,p) level of theory on which gauge‐independent atomic orbital‐DFT (GIAO‐DFT) computations at the B3LYP/cc‐pVTZ level of theory were applied to calculate the chemical shifts of the 1H, 13C and 15N nuclei. Both the site and the extent of protonation of the bi‐imidazole nucleosides were also similarly ascertained using the same methodology. Protonation at the pyridine‐type nitrogen (N‐3″) of the outer imidazole ring, the principle site of protonation, effectively eliminated the barrier to rotation about the conjoining bond yielding time‐averaged spectra experimentally. Copyright © 2004 John Wiley & Sons, Ltd.
Three‐dimensional crystallographic determination of the body‐centered‐cubic morphologies of shear‐aligned block copolymer systems
Authors: Mortensen Kell
Published: July 2004

The texture of ordered phases of block copolymer melts and gels is highly sensitive to shear. In the body‐centered‐cubic phase of a block copolymer system [polystyrene–poly(ethylene butylene)–polystyrene] mixed with oil, we show how a given textures can be controlled with the application of a specific shear rate and amplitude. The low‐amplitude shear texture is dominated by {001} planes perpendicular to the shear gradient and by the [110] axis parallel to the flow direction, that is, the {001}/[110] slip system. Detailed crystallographic studies show that both intermediate‐amplitude oscillatory shear and large‐amplitude oscillatory shear lead to twin structures with {112} planes sharing neighboring twins and [111] axes parallel to the shear flow. At an intermediate shear amplitude, the ve shear plane, defined by the shear flow direction (v) and shear vorticity direction (e), is parallel to the {112} twin planes. At a high shear amplitude, the orientation is rotated 90°, and this makes the ve shear plane parallel to the {110} crystallographic planes. The crystalline slip system is accordingly ({112}/[111] + {112}/[111]) under intermediate‐amplitude shear and ({110}/[111] + {110}/[111]) under large‐amplitude shear. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3095–3101, 2004
Formation of deprotected fuzzy blobs in chemically amplified resists
Authors: Jones Ronald L. , Hu Tengjiao , Lin Eric K. , Wu Wen‐Li , Goldfarb Dario L. , Angelopoulos Marie , Trinque Brian C. , Schmid Gerard M. , Stewart Michael D. , Willson C. Grant
Published: July 2004

The requirement of nanometer dimensional control in photolithographic patterning underlies the future of emerging technologies, including next‐generation semiconductors, nanofluids, photonics, and microelectromechanical systems. For chemically amplified resists, dimensional control is mediated by the diffusion and reaction of photogenerated acids within a polymer‐based photoresist matrix. The complex nature of the combined processes of reaction and diffusion prohibit the routine measurement of this phenomenon. Using small‐angle neutron scattering, we have measured the form of the diffusion–reaction path of a photogenerated acid within a model photoresist matrix with a labeled protection group on the polymer side group. During the deprotection reaction, changes in the scattering form factor result from the shape and form of the deprotected regions. The individual volumes or blobs of reacted material are diffuse, with a fuzzy boundary between the reacted and unreacted regions. The impact of these results on the pattern quality is also discussed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3063–3069, 2004
Scattering functions of semidilute solutions of polymers in a good solvent
Authors: Pedersen Jan Skov , Schurtenberger Peter
Published: July 2004

Expressions for analyzing small‐angle scattering data from semidilute solutions of polymers in a good solvent over a broad range of scattering vectors are examined. Three different scattering function expressions are derived from Monte Carlo simulations. The expressions are similar to those of polymer reference interaction site models, with a scattering‐vector‐dependent direct correlation function. In the most advanced model, the screening of excluded‐volume interactions beyond the overlap concentration is taken into account. Two simpler expressions, in which the screening of excluded‐volume interactions is not included, are also applied. The three models are tested against small‐angle neutron scattering (SANS) experiments on polystyrene in deuterated toluene for a broad range of molar masses and concentrations over a wide range of scattering vectors. For each model, simultaneous fits to all the measured scattering data are performed. The most advanced model excellently reproduces the SANS data over the full range of the parameters. The two simpler models fit the data almost equally well. On the basis of an extensive study, an optimal fitting strategy can be recommended for experimentalists, who want to analyze small‐angle scattering data from polymers at any concentration. For data sets that do not contain data on the single‐chain scattering function, the simpler model is recommended; it uses a direct correlation function equal to the form factor of an infinitely thin rod, which is independent of the concentration and molar mass. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3081–3094, 2004
Ferroelectric stability of BaTiO3 in a crystalline oxide on semiconductor structure
Authors: Reiner J. W. , Walker F. J. , McKee R. A. , Billman C. A. , Junquera J. , Rabe K. M. , Ahn C. H.
Published: July 2004

Recent experimental advances in the ability to grow epitaxial ferroelectrics on semiconductors have provided an opportunity to study the intrinsic properties of these interfaces. It has been reported that a heterostructure of BaTiO3 grown on germanium has a commensurate crystalline oxide interface with a nonzero interface density of states. Including these states in a model of a ferroelectric oxide on a semiconductor substrate with a top metal electrode, we find that the oxide critical thickness necessary for stability of the ferroelectric state with polarization along the interface normal is substantially lowered by the contribution to the screening by the interface states. Materials parameters for BaTiO3 and Ge give a drop in estimated critical thickness from 39 nm to 7 nm. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stability of Ru‐ and Ta‐based metal gate electrodes in contact with dielectrics for Si‐CMOS
Authors: Chen Zhiqiang , Misra Veena , Haggerty Ryan P. , Stemmer Susanne
Published: July 2004

The Ru–Ta–Si–O, Ta–Si–N–O, and Ru–Ta–Zr–O phase diagrams are important for predicting reactions at interfaces between SiO2 and ZrO2 gate dielectrics and novel Ru and Ta‐based metal gate electrodes. Simplified quaternary phase diagrams of the Ru–Ta–Si–O, Ta–Si–N–O, and Ru–Ta–Zr–O systems at 900 °C were constructed from known and estimated Gibbs free energy data, respectively. Ru is predicted to be stable in contact with ZrO2 and SiO2, whereas Ta is not stable in contact with SiO2 at temperatures around 900 °C. Stoichiometric RuTa and TaN compounds were estimated to be stable in contact with both dielectrics at 900 °C. Experimental observations of gate electrode/dielectric interfaces are discussed. They are consistent with the thermodynamic predictions within the limitations of these phase diagrams. Metastable phases, often found in TaNx films, and diffusion of species from the vapor (e.g., oxygen), in particular along grain boundaries in columnar gate electrodes, may lead to reactions not predicted by the equilibrium phase diagrams. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Response of Si and InSb to ultrafast laser pulses
Authors: Dumitrica Traian , Burzo Andrea , Dou Yusheng , Allen Roland E.
Published: July 2004

We present simulations of the response of Si and InSb to femtosecond‐scale laser pulses of various intensities. In agreement with the experiments by various groups on various materials, there is a nonthermal phase transition for each of these semiconductors above a threshold intensity. Our simulations employ semiclassical electron‐radiation‐ion dynamics (SERID), a technique which is briefly described in the text. We also introduce a new addition to the technique, which provides a simple treatment of the correction due to motion of the atomic‐orbital basis functions. We find that this correction is small in the present context, but it may be substantial in situations with more rapid atomic motion. Our expression for this correction is remarkably simple to employ because it amounts to nothing more than a generalized Peierls substitution. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bonding and structure of some high‐koxide:Si interfaces
Authors: Robertson J. , Peacock P. W.
Published: July 2004

Electron counting rules are developed to describe the bonding at interfaces between covalent networks and ionic oxides. These rules are used to describe the bonding at various idealised interfaces of Si(100) with various high dielectric constant (k) gate oxides such as HfO2, ZrO2, SrTiO3and LaAlO3. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Full‐band particle‐based simulation of SOI and GOI MOSFETs
Authors: Beysserie Sébastien , Aboud Shela , Goodnick Stephen , Thornton Trevor , Saraniti Marco
Published: July 2004

In this work we report on the 2D simulation of fully depleted Germanium‐On‐Insulator FET structures coupled with a high‐κ dielectric using a full‐band simulator. This simulator, based on the Cellular Monte Carlo method, provides an accurate transport model at the high electric fields present in the ultra‐small devices considered in this work. Simulations of similar Germanium‐ and Silicon‐On‐Insulator devices have been performed to quantitatively analyze the predicted increase in performance of Germanium‐On‐Insulator technology. A characterization and comparison of the static behavior of these devices is presented for 50 nm MOSFETs. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Löwdin's canonical orthogonalization: Getting round the restriction of linear independence
Authors: Naidu A. Ramesh , Srivastava Vipin
Published: July 2004

Löwdin's canonical orthogonalization procedure can be useful in organizing large data sets, but it is applicable only to a set of linearly independent vectors. This places a serious constraint for there can be at most n linearly‐independent vectors in an n‐dimensional space. We propose two ways of getting round this restriction so that Löwdin's procedure can be used to find the vector along which all the given vectors—any number of them in a space of arbitrary dimensionality—project maximally. Under these conditions, this orthogonalization procedure is equivalent to the principal component analysis. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Understanding the historical and cultural influences that shape generations
Authors: Coomes Michael D.
Published: July 2004

Generations are shaped by history and embedded in culture. This chapter explores how history and popular culture can be useful lenses for understanding generations.
Constructions of student development across the generations
Authors: Strange C. Carney
Published: July 2004

This chapter explores the dynamics of generational cohort differences and their potential influence on the understandings, emphases, and applications of student development theory.
Understanding diversity in millennial students
Authors: Broido Ellen M.
Published: July 2004

The Millennial generation of college students has demographics and attitudes toward diversity issues different from their predecessors; this chapter explores those differences and their implications for student affairs work.
Student affairs for a new generation
Authors: Lowery John Wesley
Published: July 2004

This chapter examines the Millennial generation's implications for the design and delivery of student affairs programs and services. The unique characteristics of the Millennial students offer insights into the programs and services that this generation of college students will want and need.
Das Niedersachsenstadion – die AWD‐Arena
Authors: Schulitz Helmut C.
Published: July 2004

Das Projekt der AWD‐Arena, das ehemalige Niedersachsenstadion, wurde als Austragungsort für die Fußballweltmeisterschaft 2006 ausgewählt. Ursprünglich 1952–1954 auf den Trümmern der Stadt des 2. Weltkriegs errichtet, wird es heute von einem multifunktionalen Stadion in eine reine Fußballarena umgebaut. Der Entwurf ist das Ergebnis eines internationalen Architekten‐ und Ingenieurwettbewerbs. Ein zentraler Aspekt des Entwurfs ist die Trennung des Dachs in zwei konzentrische Teil e, einen geschlossenen äußeren Teil in Trapezblechdekkung und einen transparenten inneren Teil , der von einer einlagigen ETFE‐Folie (Ethylen‐Tetrafluorethylen) überspannt wird. Dies ist eine Antwort auf das Problem des Rasenwachstums, das die meisten engen Fußballstadien betrifft. ETFE ist 95% UV‐lichtdurchlässig, eine Voraussetzung für jede natürliche Vegetation.

Der äußere Teil des Dachs ist nach dem Prinzip eines Speichenrades mit einem äußeren Druckring (Felge), Seilen als gekreuzte Speichen und einer offenen Nabe, die selbst eine weitere Felge bildet, an der das innere Dach befestigt ist. Das Innendach ist eine Art Tensegrity‐Konstruktion, die durch Luftstützen geprägt wird, die die Radialträger tragen und die durch zwei weitere Zugringe stabilisiert werden.
Pusan Sports Complex – ein Betonbau als Stahl‐Seil‐Tragwerk vollendet
Authors: Stauske Dieter
Published: July 2004

Mit dem Stadion Pusan wurde ein komplett in Beton geplantes Bauwerk mit einem Stahldruckring für das Dach vollendet. Damit konnte das Gewicht des Dachtragwerks von 30000 t auf 1800 t reduziert werden. Montageablauf, Kosten und Bauzeit ließen sich dadurch wesentlich verbessern.
Zur Tragfähigkeitsbewertung bestehender Bauwerke
Authors: Mehdianpour Milad , Rücker Werner , Rohrmann Rolf Günter
Published: July 2004

Ausgehend von der Zielsetzung einer kostenoptimierten Unterhaltung von bestehenden Bauwerken werden gegenwärtige nationale und internationale Normungsaktivitäten auf dem Gebiet der Bauwerksüberwachung und ‐bewertung vorgestellt. Ein derzeit in der BAM laufendes Projekt, das sich mit einem Konzept zur Tragfähigkeitsbewertung bestehender Bauwerke und dessen praktischer Umsetzung befaßt, wird inhaltlich beschrieben.
Erfassung des Windrichtungseinflusses auf die Windlasteffekte an Tragwerken
Authors: Niemann Hans‐Jürgen , Hölscher Norbert
Published: July 2004

Extreme Windstärken treten bevorzugt mit bestimmten Windrichtungen auf. Der Windlasteffekt an Tragwerken hängt deshalb von der Ausrichtung der Bauwerke gegenüber der Windrose ab. Um den Richtungseinfluß beurteilen zu können, muß auf die Tragwerksreaktion zurückgegangen werden; die meteorologische Information über die Stärkewindrose reicht nicht aus. Es wird eine Methode vorgestellt, mit der die statistische Verteilung der Tragwerksreaktion benutzt wird, um die für die Bemessung maßgebende Windgeschwindigkeit in Abhängigkeit der Windrichtung zu ermitteln. Wird der Richtungseinfluß berücksichtigt, so zeigt sich i. d. R., daß die vorhandene Sicherheit merkliche Reserven gegenüber der normgemäßen Sicherheit aufweist, die eine Minderung der Windlast erlaubt.
Störabspannungen für Stahlschornsteine
Authors: Knödel Peter
Published: July 2004

Von großen abgespannten Masten ist bekannt, daß die Abspannseile aufgrund ihrer nichtlinearen Kennlinie Schwingungen des Systems wirksam begrenzen können. Diesen Effekt kann man für Störabspannungen bei kleinen und mittleren Stahlschornsteinen nutzen, wenn man ein zusätzliches Gewicht in die leichten Seile hängt. Die Wirkung unterschiedlicher Seilvorspannung auf das Tragverhalten der Seile sowie der Anregungsmechanismus von Querschwingungen bei Stahlschornsteinen werden nachfolgend beschrieben. Die Auslegung von Störabspannungen wird in einzelnen Schritten gezeigt und durch ein Beispiel ergänzt. Einige Fragen, die noch der Klärung und Diskussion bedürfen, werden am Schluß angesprochen.
3,4‐methylenedioxymethamphetamine (MDMA) administration to rats decreases brain tissue serotonin but not serotonin transporter protein and glial fibrillary acidic protein
Authors: Wang Xiaoying , Baumann Michael H. , Xu Heng , Rothman Richard B.
Published: July 2004

Previous experiments conducted in this laboratory showed that administration of high‐dose D‐fenfluramine (D‐FEN) and p‐chloroamphetamine (PCA) decreased 5‐HT transporter (SERT) binding and tissue 5‐HT by 30–60% in caudate and whole brain tissue 2 days and 2 weeks after drug administration. However, protein expression as determined by Western blot analysis did not change in either tissue or time point, except for a 30% decrease in the caudate 2 days after PCA administration. In the present study, we studied the effect of MDMA and 5,7‐dihydroxytryptamine (5,7‐DHT) on tissue 5‐HT levels and the protein expression level of SERT and glial fibrillary acidic protein (GFAP), a validated neurotoxicity marker. Hypothesis. MDMA administration decreases SERT expression. Methods. Two weeks after MDMA administration (7.5 mg/kg i.p., q 2 h × 3 doses) or 2 weeks after i.c.v. administration of 5,7,‐DHT (150 μg/rat), male Sprague‐Dawley rats were sacrificed and the caudate, cortex, and hippocampal tissue collected. Western blots for SERT and GFAP were generated using published methods. Tissue 5‐HT levels were determined by HPLC coupled to electrochemical detection. Results. MDMA treatment decreased tissue 5‐HT in cortex, hippocampus, and caudate by about 50%. However, MDMA treatment had no significant effect on expression level of SERT and GFAP in any brain region. In contrast, 5,7‐DHT reduced tissue 5‐HT by more than 90%, decreased SERT protein expression by 20–35%, and increased GFAP by 30–39%. Conclusion. These data suggest the MDMA treatment regimen used here does not cause degeneration of 5‐HT nerve terminals. Viewed collectively with our previous results and other published data, these data indicate that MDMA‐induced persistent 5‐HT depletion may occur in the absence of axotomy. Synapse 53:240–248, 2004. Published 2004 Wiley‐Liss, Inc.
Accuracy of rectal endoscopic ultrasonography and magnetic resonance imaging in the diagnosis of rectal involvement for patients presenting with deeply infiltrating endometriosis
Authors: Chapron C. , Vieira M. , Chopin N. , Balleyguier C. , Barakat H. , Dumontier I. , Roseau G. , Fauconnier A. , Foulot H. , Dousset B.
Published: July 2004

Objective

To compare the accuracy of rectal endoscopic ultrasonography (REU) and magnetic resonance imaging (MRI) for predicting rectal wall involvement in patients presenting histologically proven deeply infiltrating endometriosis (DIE).

Methods

This was a retrospective study of a continuous series of 81 patients presenting histologically proven DIE who underwent preoperative investigations using both REU and MRI. The sonographer and the radiologist, who were unaware of the clinical findings and patient history, but knew that DIE was suspected, were asked whether there was involvement of the digestive wall.

Results

Rectal DIE was confirmed histologically in 34 of the 81 (42%) patients. For the diagnosis of rectal involvement, sensitivity, specificity and positive and negative predictive value for REU were 97.1%, 89.4%, 86.8% and 97.7% and for MRI they were 76.5%, 97.9%, 96.3% and 85.2%.

Conclusion

The sensitivity and negative predictive value of REU were higher than those of MRI suggesting that REU performs better than MRI in the diagnosis of rectal involvement for patients presenting with DIE. Prospective studies with a large number of patients are needed in order to validate these preliminary results. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Superior Performance of a Paraaortic Counterpulsation Device Compared to the Intraaortic Balloon Pump
Authors: Terrovitis John V. , Charitos Christos E. , Tsolakis Elias J. , Dolou Paraskevi , Pierrakos Charalampos N. , Siafakas Kostas X. , Nanas John N.
Published: July 2004

The purpose of this study was to compare the hemodynamic effectiveness of a 30‐ml stroke volume paraaortic counterpulsation device (PACD), presenting the advantages of ease of implantation and driving by a standard intraaortic balloon pump (IABP) console (Datascope 96, Datascope Corp., Montvale, NJ, USA) to that of a 40‐ml IABP, in the setting of experimental heart failure. In an acute heart failure model, the IABP was placed in the descending aorta and the PACD in the ascending aorta of eight pigs. Both devices were driven by the same system, and hemodynamic measurements were obtained with and without mechanical assistance. The two pumps significantly reduced the systolic and end‐diastolic aortic pressures, but the PACD reduced the latter more effectively (42.6 ± 18.1% vs 11.0 ± 9.9%, p = 0.0001). Both pumps provided significant aortic diastolic augmentation, but the counterpulsation wave of the PACD was significantly greater (augmentation of 44.8 ± 22.2% vs 37.6 ± 15.6%, p = 0.031). Both lowered the end‐diastolic left ventricular pressure with a trend toward PACD superiority (24.2 ± 13.7% vs 19.7 ± 13.5%, p = 0.064). It is concluded that the PACD, even with smaller stroke volume, is more effective than the IABP. The simplicity of its implantation, together with the ability of the standard IABP consoles to control its function, make it a promising device for mechanical assistance of the failing heart.
Plant roles and decision autonomy in multinational plant networks
Authors: Maritan Catherine A. , Brush Thomas H. , Karnani Aneel G.
Published: July 2004

The paper examines whether plants in a multinational manufacturing firm with different roles have different degrees of autonomy concerning planning, production and control decisions. Building on Ferdows’ framework for classifying international plants in a network, we empirically examine the proposition that the degree of managerial autonomy varies according to strategic role of the plant. We ask whether different plant roles require different management systems and different levels of responsibility for decisions and find evidence of differentiated fit.
Cross-language transfer of phonological awareness in low-income Spanish and English bilingual preschool children
Authors: DICKINSON DAVID K. , McCABE ALLYSSA , CLARK–CHIARELLI NANCY , WOLF ANNE
Published: July 2004

This study investigated the phonological awareness of low-income Spanish–English bilingual children, because phonological awareness has been found to be an important prerequisite for literacy acquisition and because such children have been identified as at risk for successful literacy acquisition. Our sample included 123 Spanish–English bilingual preschool children (M=49.1 months) attending Head Start programs. Children's receptive vocabulary was assessed using the Peabody Picture Vocabulary Test—3rd Edition and the Test de Vocabulario en Imagines Peabody. We assessed phonological awareness using English and Spanish versions of the Early Phonological Awareness Profile, which includes deletion detection and rhyming tasks. Emergent literacy was assessed in the child's stronger language using the Emergent Literacy Profile, which includes tests of environmental print knowledge, printed word awareness, alphabet knowledge, and early writing. Spring levels of phonological awareness in each language were most strongly related to development of phonological awareness in the other language. Final models accounted for 68% of the variance in spring English and Spanish phonological awareness. Educational implications are discussed.
Effects of the age of second language learning on the duration of first and second language sentences: The role of suppression
Authors: MACKAY IAN R. A. , FLEGE JAMES E.
Published: July 2004

The primary aim of this study was to account for the finding that late bilinguals produce longer English sentences than early bilinguals. In Experiment 1, Italians who immigrated to Canada either between the age of 2–13 years (“early bilinguals”) or 15–28 years (“late bilinguals”) repeated matched English and Italian sentences following an aural model. The early bilinguals produced shorter English than Italian sentences, whereas the late bilinguals showed the opposite pattern. The same countervailing pattern was evident in Experiment 2, where bilinguals shortened sentences by 20% when instructed to repeat sentences as rapidly as possible. Subgroups of bilinguals who reported using Italian oftenM=46% Italian use) but not seldom (M=8%) were found to have produced significantly longer English sentences than native English (NE) speakers did. The results were interpreted to mean that the late bilinguals produced longer English sentences than the early bilinguals because they needed to expend more resources to suppress their Italian subsystem than the early bilinguals. The perceptual effect of sentence duration was evaluated in Experiment 3, where pairs of English sentences differing in duration were presented to NE-speaking listeners for foreign accent ratings. A 10% shortening caused sentences spoken by late bilinguals to sound less foreign accented but it caused sentences spoken by early bilinguals to sound more foreign accented.
The case of case: Children's knowledge and use of upper- and lowercase letters
Authors: TREIMAN REBECCA , KESSLER BRETT
Published: July 2004

Research on children's spelling has focused on its phonological bases. In the present study, we examined a type of nonphonological knowledge that even young children may possess—knowledge about the distinction between upper- and lowercase letters. In Study 1, we analyzed the capitalization patterns used by children in kindergarten through second grade on words that did not contain a capital letter in their conventional spellings. The younger children, especially, often wrote with capital letters. They did so in a nonrandom way, being more likely to capitalize word-initial letters than later letters. When children inserted an uppercase letter in a noninitial position of a spelling, it tended to be a letter whose uppercase form was especially familiar to the child, the initial letter of the child's first name. In Study 2, which examined kindergartners' knowledge of the names of upper- and lowercase letters, we found further evidence that children's names influence their knowledge about letters and that some of this knowledge is case specific. Together, the results show that early spelling involves more than phonology.
The role of linguistic experience in the hemispheric processing of lexical tone
Authors: WANG YUE , BEHNE DAWN M. , JONGMAN ALLARD , SERENO JOAN A.
Published: July 2004

This study investigated hemispheric lateralization of Mandarin tone. Four groups of listeners were examined: native Mandarin listeners, English–Mandarin bilinguals, Norwegian listeners with experience with Norwegian tone, and American listeners with no tone experience. Tone pairs were dichotically presented and listeners identified which tone they heard in each ear. For the Mandarin listeners, 57% of the total errors occurred in the left ear, indicating a right-ear (left-hemisphere) advantage. The English–Mandarin bilinguals exhibited nativelike patterns, with 56% left-ear errors. However, no ear advantage was found for the Norwegian or American listeners (48 and 47% left-ear errors, respectively). Results indicate left-hemisphere dominance of Mandarin tone by native and proficient bilingual listeners, whereas nonnative listeners show no evidence of lateralization, regardless of their familiarity with lexical tone.
Physiological response properties of displaced amacrine cells of
the adult ferret retina
Authors: ABOELELA SALLY W. , ROBINSON DAVID W.
Published: July 2004

The ganglion cell layer (GCL) of the mammalian retina contains a
large number of neurons called displaced amacrine cells (DACs) that do
not project to the optic nerve. However, with the exception of the
rabbit starburst amacrine cell little is known regarding the function
of this large population due to the difficulty experienced in making
physiological recordings from these neurons. We have overcome these
difficulties and have used whole-cell patch-clamp techniques to examine
the intrinsic membrane properties of DACs in the ferret retina. Our
results indicate a large degree of diversity in their intrinsic
membrane properties. In response to maintained depolarizing current
injection, DACs responded with graded depolarization or by eliciting
either transient or sustained bursts of spiking activity. At the
resting membrane potential, 10% of the DACs generated spontaneous
spikes in either an apparently random manner or at the peak of
intrinsic waves of depolarization. The resting membrane activity of the
remaining DACs recorded could be classified into three groups that were
quiescent (28%), had robust uncorrelated synaptic activity (30%), or
underwent slow waves of depolarization (42%). Diversity was also
revealed in the membrane currents recorded in voltage-clamp where some
DACs were quiescent (19%), or exhibited robust nonrhythmic synaptic
events (42%). The remaining DACs exhibited waves of oscillatory
activity (39%), characterized by either rhythmic bursts of synaptic
events (17%) or slow inward currents (22%). Bath application of 50
μM biccuculine or 150 μM picrotoxin had no effect on the waves
of activity, however, the gap junction blocker, carbenoxolone (100
μm), blocked both oscillatory patterns. By including Lucifer yellow
and biocytin in the recording pipette, it was possible to determine the
morphology of recorded neurons and group them based on dendritic extent
as small-, medium-, or large-field DACs. There were few relationships
between these morphologically defined groups and their intrinsic
membrane properties. The present study provides the first in-depth
examination of the intrinsic membrane properties of DACs in the ferret
retina and provides new insights into the potential roles these neurons
play in the processing of visual information in the mammalian
retina.
The type 1 polyaxonal amacrine cells of the rabbit retina: A tracer-coupling study
Authors: WRIGHT LAYNE L. , VANEY DAVID I.
Published: July 2004

The type 1 polyaxonal (PA1) cell is a distinct type of axon-bearing amacrine cell whose soma commonly occupies an interstitial position in the inner plexiform layer; the proximal branches of the sparse dendritic tree produce 1–4 axon-like processes, which form an extensive axonal arbor that is concentric with the smaller dendritic tree (Dacey, 1989; Famiglietti, 1992a,b). In this study, intracellular injections of Neurobiotin have revealed the complete dendritic and axonal morphology of the PA1 cells in the rabbit retina, as well as labeling the local array of PA1 cells through homologous tracer coupling. The dendritic-field area of the PA1 cells increased from a minimum of 0.15 mm2(0.44-mm equivalent diameter) on the visual streak to a maximum of 0.67 mm2(0.92-mm diameter) in the far periphery; the axonal-field area also showed a 3-fold variation across the retina, ranging from 3.1 mm2(2.0-mm diameter) to 10.2 mm2(3.6-mm diameter). The increase in dendritic- and axonal-field size was accompanied by a reduction in cell density, from 60 cells/mm2in the visual streak to 20 cells/mm2in the far periphery, so that the PA1 cells showed a 12 times overlap of their dendritic fields across the retina and a 200–300 times overlap of their axonal fields. Consequently, the axonal plexus was much denser than the dendritic plexus, with each square millimeter of retina containing ∼100 mm of dendrites and ∼1000 mm of axonal processes. The strong homologous tracer coupling revealed that ∼45% of the PA1 somata were located in the inner nuclear layer, ∼50% in the inner plexiform layer, and ∼5% in the ganglion cell layer. In addition, the Neurobiotin-injected PA1 cells sometimes showed clear heterologous tracer coupling to a regular array of small ganglion cells, which were present at half the density of the PA1 cells. The PA1 cells were also shown to contain elevated levels of γ-aminobutyric acid (GABA), like other axon-bearing amacrine cells.
Immuocytochemical analysis of spatial organization of
photoreceptors and amacrine and ganglion cells in the tiger salamander
retina
Authors: ZHANG JIAN , YANG ZHUO , WU SAMUEL M.
Published: July 2004

In the present study, using double- or triple-label
immunocytochemistry in conjunction with confocal microscopy, we aimed
to examine the population and distribution of photoreceptors, GABAergic
and glycinergic amacrine cells, and ganglion cells, which are basic but
important parameters for studying the structure–function
relationship of the salamander retina. We found that the outer nuclear
layer (ONL) contained 82,019 ± 3203 photoreceptors, of which 52%
were rods and 48% were cones. The density of photoreceptors peaked at
∼8000 cells/mm2 in the ventral and dropped to
∼4000 cells/mm2 in the dorsal retina. In addition,
the rod/cone ratio was less than 1 in the central retina but larger
than 1 in the periphery. Moreover, in the proximal region of the inner
nuclear layer (INL3), the total number of cells was 50,576 ±
8400. GABAergic and glycinergic amacrine cells made up approximately
78% of all cells in this layer, including 43% GABAergic, 32%
glycinergic, and 3% GABA/glycine colocalized amacrine cells. The
density of these amacrine cells was ∼6500 cells/mm2
in the ventral and ∼3200 cells/mm2 in the dorsal
area. The ratio of GABAergic to glycinergic amacrine cells was larger
than 1. Furthermore, in the ganglion cell layer (GCL), among a total of
36,007 ± 2010 cells, ganglion cells accounted for 65.7 ±
1.5% of the total cells, whereas displaced GABAergic and glycinergic
amacrine cells comprised about 4% of the cells in this layer. The
ganglion cell density was ∼1800 cells/mm2 in the
ventral and ∼600 cells/mm2 in the dorsal retina. Our
data demonstrate that all three major cell types are not uniformly
distributed across the salamander retina. Instead, they exhibit a
higher density in the ventral than in the dorsal retina and their
spatial arrangement is associated with the retinal topography. These
findings provide a basic anatomical reference for the
electrophysiological study of this species.