bluuebunny/crossref_metadata_2025 huggingface dataset:
The Multiobjective Discrete Optimization Problem: A Weighted Min-Max Two-Stage Optimization Approach and a Bicriteria Algorithm
Authors: Sayın Serpil , Kouvelis Panos
Published: October 2005

We study the multiple objective discrete optimization (MODO) problem and propose two-stage optimization problems as subproblems to be solved to obtain efficient solutions. The mathematical structure of the first level subproblem has similarities to both Tchebycheff type of approaches and a generalization of the lexicographic max-ordering problem that are applicable to multiple objective optimization. We present some results that enable us to develop an algorithm to solve the bicriteria discrete optimization problem for the entire efficient set. We also propose a modification of the algorithm that generates a sample of efficient solutions that satisfies a prespecified quality guarantee. We apply the algorithm to solve the bicriteria knapsack problem. Our computational results on this particular problem demonstrate that our algorithm performs significantly better than an equivalent Tchebycheff counterpart. Moreover, the computational behavior of the sampling version is quite promising.
Agenten: Technologie für den Mainstream? (Agents: Technology for the Mainstream?)
Authors: Pokahr Alexander , Braubach Lars , Lamersdorf Winfried
Published: October 2005

Agententechnologie wird als ein vielversprechender Ansatz gesehen, die Probleme der Konstruktion komplexer Software-Systeme wie heterogene Systemumgebungen und dezentrale Strukturen besser beherrschbar zu machen. Dieser Beitrag wirft einen kritischen Blick auf den erreichten Stand der softwaretechnischen Unterstützung, den die Agententechnologie bei der Systementwicklung bietet. Da die Agententechnologie ein stark diversifiziertes Feld ist, wird versucht die unterschiedlichen Einflussfaktoren und ihre Wechselwirkungen aufzuzeigen. Zudem wird durch Beispiele aus der Praxis belegt, für welche Anwendungsfelder die vorgestellten Technologien besonders gut geeignet sind.
Bildbasierte vektorielle Geschwindigkeitsmessung texturierter Oberflächen (Image-based Vectorial Velocity Measurement of Textured Surfaces)
Authors: Horn Jan
Published: October 2005

In der Fahrzeugtechnik ist die Information von Betrag und Richtung der Fahrzeuggeschwindigkeit von äußerster Wichtigkeit. Zur Realisierung eines berührungslosen optischen Messverfahrens eignen sich dabei insbesondere CMOS-Kameras. Diese erlauben Hochgeschwindigkeitsaufnahmen schnell bewegter Objekte bei sehr kurzen Belichtungszeiten. Durch Analyse einer Bildsequenz der bewegten Straßenoberfläche mit Methoden der Bildverarbeitung kann die Relativbewegung zwischen Kamera und Oberfläche und somit die Bewegung des Fahrzeugs gemessen werden. In diesem Beitrag wird beschrieben, wie durch Beobachtung der Fahrbahn mit einer CMOS-Kamera die Kenngrößen der Fahrzeugbewegung – Geschwindigkeitsvektor und Drehrate – gemessen werden können. Anhand von korrespondierenden Punkten in aufeinander folgenden Bildern werden Transformationsparameter geschätzt. Geschwindigkeitsvektor und Drehrate können direkt aus diesen Parametern berechnet werden.
Koeffizienten und Ausgleichsrechnung: Die Messunsicherheit nach GUM. Teil 1: Ausgleichsgeraden (Coefficients and Adjustment Calculations: Measurement Uncertainty under GUM. Part 1: Best Fit Straight Lines)
Authors: Matus Michael
Published: October 2005

Die Bestimmung des linearen thermischen Ausdehnungskoeffizienten eines Prüflings ist ein typisches Beispiel, wie die eigentliche Messgröße durch eine Ausgleichsrechnung aus einer veränderlichen Anzahl von Messdaten gewonnen wird. Die notwendige Angabe der Messunsicherheit (nach GUM) solcher Größen bereitet den Anwendern erfahrungsgemäß große Schwierigkeiten. In dieser Arbeit werden für Praktiker GUM-konsistente Formeln für die Messunsicherheit der Koeffizienten von Ausgleichsgeraden abgeleitet.
Spontaneous growth of freestanding Ga nanoribbons from Cr2GaC surfaces
Authors: Sun Zheng Ming , Gupta Surojit , Ye Haihui , Barsoum Michel W.
Published: October 2005

Herein we report on the room-temperature spontaneous growth of Ga freestanding nanoribbons from Cr2GaC surfaces. An oxidation-based model is proposed to explain the growth of the nanostructures. The nanoribbons present a unique opportunity to study the behavior of electrons confined to two dimensions. The production of these Ga nanostructures could be the first step in the manufacture of gallium arsenide or nitride devices with enhanced characteristics for photonic, electronic, and catalytic applications.
Metallurgical reactions of Sn-3.5Ag solder with various thicknesses of electroplated Ni/Cu under bump metallization
Authors: Huang Chang Pin , Chen Chih , Liu C.Y. , Lin S.S. , Chen K.H.
Published: October 2005

Nickel has been widely used as an under-bump metallization (UBM) material in the microelectronics industry. The solid-state reaction between the eutectic SnAg solder bumps and three thicknesses of Ni/Cu UBM was investigated, with 5 μm-Cu/3 μm-Ni, 3 μm-Cu/2 μm-Ni, and 0 μm-Cu/1 μm-Ni. It was found that the shear strength of the solder bumps decreased after the solid-state aging at 150 °C for 200 h, and it did not change much after it was prolonged for 500 and 1000 h. Aging of the Ag3Sn intermetallic compound (IMC) and grain growth of the solder are responsible for the decrease in the shear strength. Furthermore, the shear test results indicated that the fracture mode switched from ductile to brittle for the solder bumps with 1 μm Ni after aging longer than 200 h, causing the strength of the solder to decrease abruptly. This is attributed to the consumption of the peripheral Ni layer after the solid-state aging for 1000 h. The Ni consumption rate was measured to be 0.02 μm/h1/2at 150 °C.
Competing fracture modes in brittle materials subject to concentrated cyclic loading in liquid environments: Bilayer structures
Authors: Bhowmick Sanjit , Zhang Yu , Lawn Brian R.
Published: October 2005

A preceding study of the competition between fracture modes in monolithic brittle materials in cyclic loading with curved indenters in liquid environments is here extended to brittle layers on compliant substrates. The fracture modes include outer and inner cone cracks and radial cracks that initiate from the near-contact zone and penetrate downward. Outer cone cracks are driven by stresses from superposed Hertzian and plate flexure fields; inner cone cracks also grow within these fields but are augmented by mechanical driving forces from hydraulic pumping into the crack fissures. Radial cracks are augmented by mechanical driving forces from developing quasiplasticity zones beneath the indenter. Basically, the crack-growth rates are governed by a crack velocity relation. However, the hydraulic and quasiplastic mechanical forces can cumulate in intensity with each cycle, strongly enhancing fatigue. Plate flexure generates compressive stresses at the top surface of the brittle layer, somewhat inhibiting the initiation, and tensile stresses at the lower surface, strongly enhancing the far-field propagation. The tensile stresses promote instability in the crack propagation, resulting in through-thickness penetration (failure). Experiments on a model bilayer system consisting of glass plates bonded to thick polycarbonate bases are presented as an illustrative case study. In situ observations of the crack evolution from initial growth to failure reveal that each fracture mode can dominate under certain test conditions, depending on plate thickness, maximum load, and sphere radius. Implications concerning the failure of practical layer systems, notably dental crowns, are discussed.
Effects of alloying on oxidation of Cu-based bulk metallic glasses
Authors: Tam C.Y. , Shek C.H.
Published: October 2005

The oxidation kinetics and the effects of alloying on the oxidation behaviors of copper-based bulk metallic glasses were studied. The oxidation kinetics, oxide compositions, and structures were investigated by thermogravimetric analysis (TGA), x-ray diffraction, x-ray photoelectron spectroscopy (XPS), and scanning electron microscopy. Both the TGA results and the XPS depth profile measurements showed that the oxidation resistance of Cu60Zr30Ti10 bulk metallic glass was improved by adding Hf, but it deteriorated when it was alloyed with Y. The oxide phases were found to be ZrO2, Cu2O, and CuO in samples heated at 573 K while an additional metallic Cu phase was detected in the ones heated at 773 K. A porous oxide structure was observed in the (Cu0.6Zr0.3Ti0.1)98Y2 metallic glass oxidized at 673 K, and the poor oxidation resistance of the alloy is attributed to the porous structure.
Effects of Fe2O3 addition on microstructure and piezoelectric properties of 0.2PZN–0.8PZT ceramics
Authors: Zhu Man-Kang , Lu Peng-Xian , Hou Yu-Dong , Wang Hao , Yan Hui
Published: October 2005

In this work, the effect of Fe2O3 addition on the microstructure and piezoelectric properties of Pb(Zn1/3Nb2/3)0.2Ti0.4Zr0.4O3 (0.2PZN–0.8PZT) ceramics were investigated. The studies indicated that the solution limit of Fe2O3 in the lattice of perovskite structure was about 0.1 wt%. Phase analysis shows that small addition of doping Fe2O3 results in the phase evolution from rhombohedral to tetragonal, sharp decrease of the Curie temperature, and remarkable increase of the grain size. Meanwhile, Fe2O3 addition within the solution limit led to the increase of the εr, kp, and d33. It is believed that the variation in the dielectric and piezoelectric properties are closely related to the microstructure change, phase evolution, and tetragonal distortion as Fe2O3 added.
Dielectric and microstructural properties of barium titanate zirconate thin films on copper substrates
Authors: Ihlefeld J.F. , Maria J-P. , Borland W.
Published: October 2005

Barium titanate zirconate, Ba(Ti1−xZrx)O3 (0 ≤ x ≤ 0.25), thin films were deposited via the chemical solution deposition (CSD) method directly on copper foils. The films were processed in a reductive atmosphere containing nitrogen, water vapor, and hydrogen gas at 900 °C to preserve the metallic copper substrate during crystallization. Increasing the fraction of BaZrO3 revealed several effects, including an increase in unit cell dimensions, a decrease in both the temperature and value of the maximum permittivity, as well as a decrease in the average grain size of the films. The decrease in the relative permittivity was attributed to a grain size effect as opposed to zirconium substitution. In film compositions containing 25 mol% BaZrO3, the permittivity below Tmax became dispersive, and the ferroelectric transitions became increasingly diffuse. These characteristics suggest relaxor-like behavior. The dielectric tunability of Ba(Ti1−xZrx)O3 was studied at room temperature and at Tmax for each composition. There was little variation in the tunability with measurement temperature; however compositions that were ferroelectric at room temperature saw a decrease in hysteresis at Tmax, and all compositions showed an increase in permittivity.
Failure of curved brittle layer systems from radial cracking in concentrated surface loading
Authors: Rudas Matthew , Qasim Tarek , Bush Mark B. , Lawn Brian R.
Published: October 2005

A study was made of radial crack evolution in curved brittle layers on compliant support substrates. Three-dimensional boundary element analysis was used to compute the stepwise growth of radial cracks that initiate at the bottom surfaces of glass on polymeric support layers, from initiation to final failure. The algorithm calculates reconstituted displacement fields in the near-tip region of the extending cracks, enabling direct evaluation of stress-intensity factors. Available experimental data on the same material systems with prescribed surface curvatures were used to validate the essential features of the predicted crack evolution, particularly the stability conditions prior to ultimate failure. It was shown that the critical loads to failure diminish with increasing surface curvature. Generalization of the ensuing fracture mechanics to include alternative brittle-layer/polymer-substrate systems enabled an explicit expression for the critical load to failure in terms of material properties and layer thicknesses. Implications concerning practical layer systems, particularly dental crowns, are briefly discussed.
Library Preparation using an Aspirating-Dispensing Ink-Jet Printer for Combinatorial Studies in Ceramics
Authors: Wang Jian , Evans Julian R.G.
Published: October 2005

This paper describes an aspirating-dispensing ink-jet printer embedded in a combinatorial robot for high throughput studies in ceramics; LUSI, the London University Search Instrument. The process of reformatting well-plates from source inks and printing ceramic samples is described. Precautions against evaporation, sedimentation of colloidal suspensions, and segregation of mixtures during drying are taken to convert compositions specified in a spreadsheet into the form of ∼1 mm radius drops. It is concluded that when these precautions are taken, commercially available powders can be combinatorially mixed in LUSI to produce samples of2.4 mg to within 1–3 wt% accuracy.
Effect of heat treatment on anodization and electrochemical behavior of AZ91D magnesium alloy
Authors: Hsiao Houng-Yu , Tsai Wen-Ta
Published: October 2005

The anodic films formed on AZ91D magnesium alloy after heat treatment were analyzed and their electrochemical properties were investigated. The results showed that the cooling rate had a significant influence on the microstructure evolution of the AZ91D magnesium alloy after solution heat treatment at 440 °C for 20 h in N2 atmosphere. A single-phase microstructure was observed when the alloy was quenched in water after solution heat treatment. However, a duplex structure consisting of both α and β phases was found if the solution-annealed alloy was cooled in air. The differences in microstructure of the heat treated AZ91D magnesium alloy gave rise to a significant change in the property of the anodic film formed in 3 M KOH + 0.21 M Na3PO4 + 0.6 M KF + 0.15 M Al(NO3)3 electrolyte. During the early stage of anodization, for the as-cast alloy, inhomogeneous anodic films were formed exhibiting relative rough surface appearances. A rather smooth anodic film was formed for the solution-annealed AZ91D magnesium alloy either followed by air cooling or water-quenched. The surface and cross section appearance was almost the same regardless of the prior heat treatment after anodizing for 20 min. The corrosion resistances of the various anodized AZ91D magnesium alloy were evaluated and compared by employing electrochemical impedance spectroscopy (EIS). The results demonstrate that the anodic film formed on the water-quenched AZ91D magnesium alloy had a slightly higher polarization resistance than that formed on the as-cast alloy. The highest polarization resistance of anodic film was found for that formed on annealed and air-cooled alloy. The presence of Al-rich β phase on the surface gave rise to the formation of a more protective anodic film which consisted of a great amount of Al2O3.
Luminescence properties of R2MoO6:Eu3+ (R = Gd, Y, La) phosphors prepared by Pechini sol-gel process
Authors: Pang Maolin , Liu Xiaoming , Lin Jun
Published: October 2005

R2MoO6:Eu3+ (R = Gd, Y, La) phosphors were prepared by the Pechini sol-gel process. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), reflectance spectra, photoluminescence (PL) spectra, and lifetimes were used to characterize the resulting phosphors. The results of XRD indicate that all of the R1.96Eu0.04MoO6 (R = Gd, Y, La) phosphors crystallized completely at 800 °C. Y1.96Eu0.04MoO6 and Gd1.96Eu0.04MoO6 are of isomorphous monoclinic (α) structure, while La1.96Eu0.04MoO6 preferentially adopts the tetragonal (γ) form. FE-SEM study reveals that the samples mainly consist of aggregated particles with an average grain size ranging from 100 to 250 nm. The luminescent properties of R2MoO6:Eu3+ (R = Gd, Y, La) phosphors are largely dependent on their structure, grain size, and powder morphology. The isomorphous Y2MoO6:Eu3+ and Gd2MoO6:Eu3+ phosphors show very similar luminescence properties, which differ greatly from that of the La2MoO6:Eu3+ phosphor.
Immobilization of hemoglobin on stable mesoporous multilamellar silica vesicles and their activity and stability
Authors: Zhu Yufang , Shen Weihua , Dong Xiaoping , Shi Jianlin
Published: October 2005

A stable mesoporous multilamellar silica vesicle (MSV) was developed with a gallery pore size of about 14.0 nm. A simulative enzyme, hemoglobin (Hb), was immobilized on this newly developed MSV and a conventional mesoporous silica material SBA-15. The structures and the immobilization of Hb on the mesoporous supports were characterized with x-ray diffraction, transmission electron microscopy, N2 adsorption-desorption isotherms, Fourier transform infrared, ultraviolet-visible spectroscopy, and so forth. MSV is a promising support for immobilizing Hb due to its large pore size and high Hb immobilization capacity (up to 522 mg/g) compared to SBA-15 (236 mg/g). Less than 5% Hb was leached from Hb/MSV at pH 6.0. The activity study indicated that the immobilized Hb retained most peroxidase activity compared to free Hb. Thermal stability of the immobilized Hb was improved by the proctetive environment of MSV and SBA-15. Such an Hb-mesoporous support with high Hb immobilization capacity, high activity, and enhanced thermal stability will be attractive for practical applications.
Use of GIS-Derived Landscape-Scale Habitat Features to Explain Spatial Patterns of Fish Density in Michigan Rivers
Authors: Creque Sara M. , Rutherford Edward S. , Zorn Troy G.
Published: October 2005

Both site- and landscape-scale processes play important roles in the biological communities of rivers. Understanding the influences of these processes on fish abundance can help direct management and research efforts toward appropriate habitat variables and scales. We used multiple linear regression analysis of a regional fish and habitat database to determine the feasibility of using geographical information systems (GIS)–derived landscape-scale habitat variables to explain the spatial variation in the density of five sport fish species (Chinook salmon Oncorhynchus tshawytscha, steelhead O. mykiss, brown trout Salmo trutta, brook trout Salvelinus fontinalis, and white sucker Catostomus commersonii) in the rivers of Michigan's Lower Peninsula. We compared these models with those developed using site-scale variables traditionally measured in the field. Landscape-scale riverine habitat variables obtained through GIS analysis and modeling of catchment characteristics accounted for 18–69% of the variation in fish density. Landscape estimates of mean July water temperature were negatively correlated with the density of brook trout, brown trout, and Chinook salmon. Drainage area was negatively correlated with the density of steelhead and white suckers, and 90% exceedence flow yield (a measure of flow stability) was positively correlated with the density of Chinook salmon and steelhead. Site-scale habitat variables explained less (12–57%) of the variation in fish density than landscape-scale variables. In the site-scale models, depth was negatively related to all species' densities, and the percentage of soft substrates was positively correlated only with white suckers. Although there was still much unexplained variation in density, our models provide insight into key habitat variables that influence fish density patterns on a large scale.
Understanding novel structures through form-finding
Authors: Lewis Wanda
Published: October 2005

Society expects civil engineers to continue to produce exciting and innovative structures, particularly for landmark buildings and bridges. However, recent high-profile failures call for a review of commonly used design methodologies. Current engineering design practice tends to replace knowledge of mechanics by codes of practice and physical modelling by computer-based calculations.This paper suggests that ‘form-finding’, a combined physical and mathematical modelling technique used to develop tension and shell structures, should also be applied where innovative designs are envisaged.
Civil engineering—still a job for the boys?
Authors: Hodgkinson Liz , Hamills Les
Published: October 2005

Women are still significantly under-represented in the civil engineering profession in Britain. For example, only 13% of home university applicants in 2003 were women. Based on focus-group interviews and a quantitative survey of school students, this paper reviews the image of engineering in UK schools and outlines the factors which cause girls (and some boys) to reject engineering as a career. It suggests a number of strategies that might help to attract more women to the profession. It also suggests the profession may not be able to achieve a gender balance by itself, since part of the problem is society's gender stereotyping of school subjects and careers.
Numerical analysis of a landslide in soils with strain-softening behaviour
Authors: Troncone A.
Published: October 2005

The results of an analysis concerning a landslide of great dimensions, which occurred at Senise (Southern Italy) on 26 July 1986, are presented. The landslide was of a translational type, and the failure developed within a thin clayey silt layer interbedded by a slightly cemented sand formation. Both these soils experienced a pronounced strain-softening behaviour during laboratory tests. From the analyses performed using the traditional limit equilibrium approach, it has been found that the average operational resistance along the sliding surface was less than that of the peak and greater than the residual resistance deduced from the laboratory tests. As a consequence, it has been postulated that a progressive failure had occurred. Such a failure process can be appropriately studied using methods that are capable of simulating the formation and development of shear zones, where strain is localised. From a computational point of view this presents many difficulties, because the numerical procedures currently used are very often affected by a lack of convergence, and the solution may depend strongly on the mesh adopted. In order to overcome these numerical drawbacks, in the present study use is made of both an elasto-viscoplastic constitutive model and a nonlocal elasto-viscoplastic model implemented in a finite element code. The Mohr–Coulomb plastic law is adopted, and the strain-softening behaviour of the soil is simulated by reducing the strength parameters with the accumulated deviatoric plastic strains. The results of the analysis show that a progressive failure occurred owing to deep excavations carried out at the toe of the slope. In addition, the soil mass involved in the sliding and the location of the failure surface deduced from the numerical simulation are found to be very similar to those observed.
Facile processing of clays into organically‐modified aerogels
Authors: Somlai Louis S. , Bandi Suneel A. , Schiraldi David A. , Mathias Lon J.
Published: October 2005

A facile process for the conversion of clay powders to organically modified clay aerogels (OMCAs) is reported. The resultant clay aerogels are of potential interest for a variety of applications, by themselves, or as a component in composite materials. Freeze‐drying aqueous clay‐surfactant solutions isolates these highly organized materials. Robust OMCAs are formed from clay‐surfactant compositions that initially produce stable surfactant modified clay‐water suspensions. Characterization of the OMCA by FTIR, WAXD, and TGA confirms the retention of surfactant after freeze‐drying, while SEM and porosimetry data show a structural reorganization of clay sheet bundles. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Successful umbilical cord blood transplantation for severe chronic active Epstein‐Barr virus infection after the double failure of hematopoietic stem cell transplantation
Authors: Ishimura Masataka , Ohga Shouichi , Nomura Akihiko , Toubo Taikai , Morihana Eiji , Saito Yusuke , Nishio Hisanori , Ide Makoto , Takada Hidetoshi , Hara Toshiro
Published: October 2005

An 11‐year‐old boy with severe chronic active Epstein‐Barr virus infection (CAEBV) underwent successful cord blood transplantation (CBT) after consecutive failure of peripheral blood and bone marrow transplantation from his HLA‐mismatched mother. CB cells from an unrelated donor were infused after conditioning with total body irradiation (12 Gy), melphalan (120 mg/m2), and etoposide (600 mg/m2). Complete remission without circulating EBV‐DNA has continued for 15 months after a delayed hematologic recovery. This is the first successful report of CBT for CAEBV. CB may therefore be an alternate source of stem cells for the curative treatment of CAEBV, despite the absence of EBV‐specific cytotoxic T lymphocytes. Am. J. Hematol. 80:207–212, 2005. © 2005 Wiley‐Liss, Inc.
Possible association between Budd‐Chiari syndrome and gemtuzumab ozogamicin treatment in a patient with refractory acute myelogenous leukemia
Authors: Kurt Mevlüt , Shorbagi Ali , Altundag Kadri , Elkiran Tamer , Güllü Ibrahim , Kansu Emin
Published: October 2005

Gemtuzumab ozogamicin (GO; CMA‐676; Mylotarg™) is a chemotherapeutic agent approved for the treatment of CD33‐positive acute myelogenous leukemia in patients of age 60 years or older after first relapse. Hepatic veno‐occlusive disease has been reported to develop as a late complication of gemtuzumab ozogamicin treatment. A patient who developed Budd‐Chiari Syndrome with hepatic vein thrombosis following treatment with GO is presented. This complication has not been previously reported, and it deserves to be considered as a possible adverse effect of gemtuzumab ozogamicin. Am. J. Hematol. 80:213–215, 2005. © 2005 Wiley‐Liss, Inc.
Minimal residual disease (MRD) monitoring using rearrangement of T‐cell receptor and immunoglobulin H gene in the treatment of adult acute lymphoblastic leukemia patients
Authors: Toubai Tomomi , Tanaka Junji , Ota Shuichi , Fukuhara Takashi , Hashino Satoshi , Kondo Takeshi , Kasai Masaharu , Kakinoki Yasutaka , Masauzi Nobuo , Morioka Masanobu , Kawamura Tsugumichi , Iwasaki Hiroshi , Asaka Masahiro , Imamura Masahiro
Published: October 2005

We evaluate whether molecular monitoring of minimal residual disease (MRD) using TCR δ (TCRD), TCR γ (TCRG), and immunoglobulin H (IgH) gene rearrangements in the bone marrow (BM) is correlated with clinical events in ALL patients. The 14 patients enrolled in this study included 6 males and 8 females with a median age of 53 years (range, 25–79 years), and the median duration of follow‐up was 417 days (range, 57–617 days). The median WBC count was 11.3 × 109/L at diagnosis. All patients had L2 type ALL. Eleven patients had a monoclonal pattern of IgH (7), TCRD (3) and TCRG (1), and 3 patients had two clonal patterns. Eleven of the 14 patients achieved the first complete remission (CR) after the first induction chemotherapy. We analyzed 9 of 11 CR patients who could be examined immediately after induction chemotherapy (including re‐induction therapy). Event‐free survival (EFS, 0%) and disease‐free survival (DFS, 0%) at 1 year in CR patients with MRD level ≥10−3 (n = 3) were significantly lower than those in CR patients with MRD level <10−3 (n = 6) (log‐rank test, P = 0.013, 0.013). A lower MRD in BM value after induction chemotherapy was associated significantly with longer survival in the log‐rank test. Our data provide evidence that molecular MRD status of BM is a strong predictor of outcome in adult ALL. Am. J. Hematol. 80:181–187, 2005. © 2005 Wiley‐Liss, Inc.
Prevention of hepatitis B reactivation with lamivudine in hepatitis B virus carriers with hematologic malignancies treated with chemotherapy—A prospective case series
Authors: Vassiliadis Themistoklis , Garipidou Vassilia , Tziomalos Konstantinos , Perifanis Vassilios , Giouleme Olga , Vakalopoulou Sofia
Published: October 2005

Administration of immunosuppressive treatment in hepatitis B virus carriers with malignancies is associated with the risk of hepatitis B reactivation. This complication is more frequent in patients with hematologic malignancies because administration of corticosteroids, the mainstay of treatment of these patients, is an independent risk factor for hepatitis B reactivation. When lamivudine is given prior to chemotherapy, it prevents the viral replication during the immunosuppression period; therefore, it might reduce the risk of hepatitis B exacerbation. We performed a prospective study to assess the efficacy of prophylactic administration of lamivudine in this setting. Ten hepatitis B virus carriers with hematologic malignancies were included in this study; seven were HBsAg positive, and three had isolated antiHBc and detectable HBV‐DNA levels. Nine patients were given corticosteroids after the administration of lamivudine. Lamivudine was given per os at a dose of 100 mg once daily. In four patients that had not been previously treated with chemotherapy, lamivudine was started 19 days (median) (range, 0–35 days) prior to the onset of chemotherapy. The administration of lamivudine has not stopped since in any of our patients. After a median follow‐up of 15 months (range 6–38 months), no hepatitis B reactivation was observed. HBV‐DNA levels were decreased in all 6 patients who had detectable HBV‐DNA at baseline. Lamivudine was well tolerated. Chemotherapy regimens were administered as planned, and their effectiveness was not compromised by lamivudine. In conclusion, prophylactic administration of lamivudine should be considered as a means of reducing the frequency of hepatitis B reactivation in hepatitis B virus carriers with hematologic malignancies who are being treated with chemotherapy. Am. J. Hematol. 80:197–203, 2005. © 2005 Wiley‐Liss, Inc.
Subgroups of Alzheimer's disease based on cerebrospinal fluid molecular markers
Authors: Iqbal Khalid , Flory Michael , Khatoon Sabiha , Soininen Hilkka , Pirttila Tuula , Lehtovirta Maarit , Alafuzoff Irina , Blennow Kaj , Andreasen Niels , Vanmechelen Eugeen , Grundke‐Iqbal Inge
Published: October 2005

Alzheimer's disease, the most common cause of dementia, is multifactorial and heterogeneous; its diagnosis remains probable. We postulated that more than one disease mechanism yielded Alzheimer's histopathology, and that subgroups of the disease might be identified by the cerebrospinal fluid (CSF) levels of proteins associated with senile (neuritic) plaques and neurofibrillary tangles. We immunoassayed levels of tau, ubiquitin, and Aβ1‐42 in retrospectively collected CSF samples of 468 clinically diagnosed Alzheimer's disease patients (N = 353) or non‐Alzheimer's subjects (N = 115). Latent profile analysis assigned each subject to a cluster based on the levels of these molecular markers. Alzheimer's disease was subdivided into at least five subgroups based on CSF levels of Aβ1‐42, tau, and ubiquitin; each subgroup presented a different clinical profile. These subgroups, which can be identified by CSF analysis, might benefit differently from different therapeutic drugs. Ann Neurol 2005;58:748–757
Do‐it‐yourself information technology: Role hybridization and the design–use interface
Authors: Fleischmann Kenneth R.
Published: October 2005

Information technology designers and users are generally treated as interacting yet distinct groups. Although approaches such as participatory design attempt to bring these groups together, such efforts are viewed as temporary and restricted to a specific knowledge domain where users can share key information and insights with designers. The author explores case studies that point to a different situation, role hybridization. Role hybridization focuses on the ability of individuals to shift from one knowledge domain to another, thus allowing for simultaneous membership within two otherwise distinct social worlds. While some studies focus on the ability of designers to act as users, this study focuses on the opposite situation, users who become designers. Interview and participant observation data is used to explore hybrid user–designers in two case studies: frog dissection simulations used in K‐12 biology education and human anatomy simulations used in medical education. Hybrid users as designers are one part of a larger design–use interface, illustrating the mutually constructive relationship between the activities of information technology design and use. Users as designers also challenge the traditional power relationship between designers and users, leading to a novel and exciting form of user‐centered design.
QPO as the Rosetta Stone for understanding black hole accretion
Authors: Abramowicz M. A.
Published: October 2005

Quasi‐periodic oscillations (QPO) seen in the X‐ray fluxes of individual neutron stars and black hole sources are one of most intriguing phenomena in today's astrophysics. The QPO nature is visibly determined by super‐strong Einstein's gravity. I argue here that it also profoundly depends on the MRI turbulence in accretion flows. Understanding the QPO physics may therefore guide accretion theory out of its present state of confusion. Readers will find here an up‐to‐date, comprehensible account of what is known, and what is not, about the QPO physics. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Turbulence and its parameterization in accretion discs
Authors: Brandenburg A.
Published: October 2005

Accretion disc turbulence is investigated in the framework of the shearing box approximation. The turbulence is either driven by the magneto‐rotational instability or, in the non‐magnetic case, by an explicit and artificial forcing term in the momentum equation. Unlike the magnetic case, where most of the dissipation occurs in the disc corona, in the forced hydrodynamic case most of the dissipation occurs near the midplane. In the hydrodynamic case evidence is presented for the stochastic excitation of epicycles. When the vertical and radial epicyclic frequencies are different (modeling the properties around rotating black holes), the beat frequency between these two frequencies appear to show up as a peak in the temporal power spectrum in some cases. Finally, the full turbulent resistivity tensor is determined and it is found that, if the turbulence is driven by a forcing term, the signs of its off‐diagonal components are such that this effect would not be capable of dynamo action by the shear–current effect. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray spectral states and high‐frequency QPOs in black holebinaries
Authors: Remillard R. A.
Published: October 2005

The high‐frequency quasi‐periodic oscillations (HFQPOs) in the X‐ray emission of black hole binaries and candidates are briefly reviewed with respect to the question of X‐ray states. We use the prescription of McClintock & Remillard (2005), in which X‐ray spectra and power density spectra are used to differentiate three main states of active accretion: “thermal”, “hard”, and “steep power‐law”. Respectively, each state emphasizes a different physical element that may contribute radiation: the accretion disk, a jet, and a compact non‐thermal corona. We focus on the four sources that exhibit pairs of HFQPOs with frequencies that scale in a 3:2 ratio. All of these HFQPOs are associated with the steep power‐law (SPL) state. Furthermore, there is a clear trend in which the 2ν 0 oscillation is seen when the source has high X‐ray luminosity, while the 3ν 0 QPO is seen at lower luminosity. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The QPO phenomenon
Authors: van der Klis M.
Published: October 2005

Aspects of QPOs in the X‐ray flux of low mass X‐ray binaries are reviewed, with particular attention to the comparison between the QPOs in black holes and those in neutron stars. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Drop of coherence of the lower kilo‐Hz QPO in neutron stars: Is there a link with the innermost stable circular orbit?
Authors: Barret D. , Olive J.‐F. , Coleman Miller M.
Published: October 2005

Using all available archival data from the Rossi X‐ray Timing Explorer (RXTE), we follow the frequency of the kilo‐Hz QPOs in three low luminosity neutron star low mass X‐ray binaries; namely 4U 1636‐536, 4U 1608‐522, and 4U 1735‐44. Following earlier work by Barret et al. (2005a,b), we focus our analysis on the lower kilo‐Hz QPO, for which we study the dependency of its quality factor (Q = ν/ Δν , where Δν is the FWHM) and amplitude as a function of frequency over a range covering from 500 Hz to 1000 Hz. As previously found for 4U 1636‐536, we show that the quality factor of the lower kilo‐Hz increases with frequency up to a maximum frequency around 800 Hz, beyond which an abrupt drop of its coherence is observed down to a limiting frequency where the QPO disappears completely. Simultaneously the amplitude of the QPOs is almost constant below the peak frequency and starts to decrease smoothly afterwards. The peak frequency is 850 Hz, 820 Hz, 740 Hz whereas the limiting frequency is 920 Hz, 900 Hz and 830 Hz for 4U 1636‐536, 4U 1608‐522 and 4U 1735‐44 respectively. A ceiling of the lower QPO frequencies is also seen clearly in a frequency versus count rate diagram for all sources. This behavior is reproducible within an object and between objects. We suggest here that the drop of coherence of the lower QPO may be a geometry‐related effect, which could be related to the last stable circular orbit. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The statistics of Sco X‐1 kHZ QPOs
Authors: Bulik T.
Published: October 2005

Recently an additional technique was applied to investigate the properties of kHz QPOS, i.e. the analysis of the distribution of frequency ratios or frequencies themselves. I review the results of such work on the data from Sco X‐1: (Abramowicz et al. 2003), which was later criticized by Belloni, Méndez & Homan (2005). I .nd that the findings of the latter paper are consistent with results presented earlier: kHz QPOs cluster around the value corresponding to the frequency ratio of 2/3. I also discuss the random walk model of kHz QPOs and possible future observations needed to verify it. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Boundary layer emission in luminous LMXBs
Authors: Gilfanov M. , Revnivtsev M.
Published: October 2005

We show that aperiodic and quasiperiodic variability of bright LMXBs – atoll and Z‐sources – on ∼ sec‐msec time scales is caused primarily by variations of the luminosity of the boundary layer. The emission of the accretion disk is less variable on these time scales and its power density spectrum follows P disk(f ) ∝ f –1 law, contributing to observed flux variation at low frequencies and low energies only. The kHz QPOs have the same origin as variability at lower frequencies, i.e. independent of the nature of the “clock”, the actual luminosity modulation takes place on the neutron star surface. The boundary layer spectrum remains nearly constant in the course of the luminosity variations and is represented to certain accuracy by the Fourier frequency resolved spectrum. In the investigated range of $ \dot M $ ∼ (0.1 – 1) $ \dot M $Edd it depends weakly on the global mass accretion rate and in the limit $ \dot M $ ∼ $ \dot M $Edd is close toWien spectrum with kT ∼ 2.4 keV. Its independence on the global value of $ \dot M $ lends support to the theoretical suggestion by Inogamov & Sunyaev (1999) that the boundary layer is radiation pressure supported.

Based on the knowledge of the boundary layer spectrum we attempt to relate the motion along the Z‐track to changes of physically meaningful parameters. Our results suggest that the contribution of the boundary layer to the observed emission decreases along the Z‐track from conventional ∼50% on the horizontal branch to a rather small number on the normal branch. This decrease can be caused, for example, by obscuration of the boundary layer by the geometrically thickened accretion disk at $ \dot M $ ∼ $ \dot M $Edd. Alternatively, this can indicate significant change of the structure of the accretion flow at $ \dot M $ ∼ $ \dot M $Edd and disappearance of the boundary layer as a distinct region of the significant energy release associated with the neutron star surface. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High frequency QPOs, nonlinear oscillations in strong gravity
Authors: Kluźniak W.
Published: October 2005

Some of the more promising ideas about the origin of the high frequency variability (kHz QPOs) in the observed X‐ray emissions of low‐mass X‐ray binaries are contrasted with less promising ones. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
For whom the disc tolls
Authors: Lasota J.‐P.
Published: October 2005

Report on the Nordita Workdays on Quasi‐Peridic Oscillations (QPOs). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Direct Fmoc/tert‐Bu solid phase synthesis of octamannosyl polylysine dendrimer–peptide conjugates
Authors: Kantchev Eric Assen B. , Chang Chung‐Chieh , Chang Ding‐Kwo
Published: October 2005

The mannose binding proteins on the surface of the dendritic cells are responsible for capture of pathogens in the early stages of immune response. Conjugation to mannose dendrimers is a rarely explored but potentially powerful strategy for enhancing immunogenicity of synthetic peptides relying on direct delivery to dendritic cells. We describe a general protocol for preparation of pure, monodisperse third‐generation mannosylated poly‐L‐lysine dendrimer‐peptide conjugates using direct, machine‐assisted Fmoc/t‐Bu solid phase peptide synthesis. The glycodendrons were elaborated onto the N‐ or C‐terminus of sequences derived from HIV‐1 gp41, SARS‐CoV S2 protein, and Influenza Hemagglutinin (consisting of 15–44 residues). The products were obtained in a homogeneous state after cleavage from the resin, deprotection, and a single purification on semipreparative RP–HPLC. © 2005 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 84: 232–240, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Determining particle density distribution of expanded bed adsorbents
Authors: Hassan Sally , Titchener‐Hooker Nigel , Willoughby Nik
Published: October 2005

This study presents an experimental approach to measure the density distribution of expanded bed adsorption (EBA) matrices. We report on the use of a series of solutions of caesium trifluoroacetate (CsTFA) of varying density spun in a laboratory centrifuge so as to separate representative matrix samples on the basis of bead density. Mass data was used to plot a decumulative density distribution for the matrix. By performing laser light scattering‐based measurements on the same samples of matrix the variation in particle size with density was determined. Particle settling velocity distributions were then calculated using these data and compared with a settling velocity distribution calculated on the basis of an assumed constant bead density. The study demonstrates a reliable and simple method for the characterisation of matrix density distribution. For the case of the Streamline matrices tested the particle size distribution is constant with varying bead density. Bead densities varied from 1.5 to 2.1 g/cm3 in the CsTFA solutions. These were then adjusted using bead porosity to give a density range of 1.11–1.33 g/cm3 in aqueous buffer (assumed 1.0 g/cm3) The differences in resultant settling velocity distributions when based upon measured density distribution than when based upon an assumed mean density value were shown to be insignificant. This result confirms experimentally that an assumption of a single constant mean density for EBA particles is acceptable for hydrodynamic modelling and performance prediction purposes. © 2005 Wiley Periodicals, inc.
Optimization of DsRed production in Escherichia coli: Effect of ribosome binding site sequestration on translation efficiency
Authors: Pfleger Brian F. , Fawzi Nicolas J. , Keasling Jay D.
Published: October 2005

DsRed‐Express, a popular reporter protein, cannot be expressed in Escherichia coli using a consensus ribosome binding site (RBS) potentially due to basepairing in the RBS that inhibits translation initiation. Saturation mutagenesis was used to probe for a gene sequence that minimized basepairing in the RBS while maintaining the same spectral properties and maturation characteristics as DsRed‐Express. The new DsRed, designated here as RFPEC for E. coli optimized red fluorescent protein, fluoresces 2.5 times greater than DsRed‐Express when expressed from the same vector. © 2005 Wiley Periodicals, inc.
Comparison of melatonin, vitamin E and L‐carnitine in the treatment of neuro‐ and hepatotoxicity induced by thioacetamide
Authors: Túnez Isaac , Muñoz M. Carmen , Medina Francisco J. , Salcedo Manuel , Feijóo Montserrat , Montilla Pedro
Published: October 2005

This study was designed to evaluate and compare the effect of melatonin, vitamin E and L‐carnitine on brain and liver oxidative stress and liver damage. Oxidative stress and hepatic failure were produced by a single dose of thioacetamide (TAA) (150 mg kg−1) in Wistar rats. A dose of either melatonin (3 mg kg−1) vitamin E (20 mg kg−1) or L‐carnitine (100 mg kg−1) was used. Blood samples were taken from the neck vasculature in order to determine ammonium, blood urea nitrogen (BUN) and liver enzymes. Lipid peroxidation products, glutathione (GSH) content and antioxidative enzymes were determined in cerebral and hepatic homogenates. The results showed a decrease in BUN and in the antioxidant enzymes activities and GSH in the brain and liver. Likewise, TAA induced significant enhancement of lipid peroxidation products levels in both liver and brain, as well as in ammonia values. Melatonin, vitamin E and L‐carnitine, although melatonin more significantly, decreased the intensity of the changes produced by the administration of TAA alone. Furthermore melatonin combined with TAA, decreased the ammonia levels and increased the BUN values compared with TAA animals. Also it was more effective than vitamin E or L‐carnitine in these actions. These data show the protective effect of these agents, especially melatonin, against oxidative stress and hepatic damage present in fulminant hepatic failure. Copyright © 2005 John Wiley & Sons, Ltd.