bluuebunny/crossref_metadata_2025 huggingface dataset:
A Contribution of Andrea Palladio to the Study of Roman Thermae
Authors: La Follette Laetitia
Published: April 2006

Andrea Palladio's measured plan of a bath complex on the Aventine Hill in Rome is of considerable interest in view of current skepticism about the archaeological accuracy of Palladio's studies of baths. This article shows first that the drawing is the result of Palladio's own survey of this complex, the Baths of Trajan Decius (A. D. 249-51); secondly it demonstrates the accuracy of Palladio's measurements; and thirdly, on the basis of Palladio's inscription on the plan, it redates the drawing to Palladio's last trip to Rome in 1554, and argues that Palladio learned of the complex from the Roman antiquarian and archaeologist, Pirro Ligorio. The plan of the Baths of Decius thus illustrates that Palladio's interest in Roman baths went beyond the most famous examples of thermae in Rome. His survey is shown to have been extremely accurate in measuring the remains of this complex, while his inscription indicates that he sought the most up-to-date (albeit erroneous) antiquarian information for the lesser-known monuments he drew.
Architectural Invention in Sacred Structures: The Case of Vesara Temples of Southern India
Authors: Sinha Ajay J.
Published: April 2006

The article explores the nature of architectural invention in Indian sacred structures by analyzing a group of eleventh-century sandstone temples in the Karnataka region of southern India. Identifying a variety of experiments in a closely related group, it refutes a commonly held scholarly assumption that Indian temples follow architectural norms ordained by India's religious traditions-an assumption fed by Western definitions of individuality and originality. These Karnataka temples demonstrate that their architects-while mostly unknown-fundamentally changed the formal as well as the conceptual basis of southern architecture they had inherited. Their formal choices, manipulating regional conventions as well as opening up their structures to include references from other regions, led to a new, consciously modern form of architecture whose modernity has been overlooked by scholars. Scholars have tended to call this new regional invention Vesara (Sanskrit "mule" or "hybrid"), defining it as a derivative style of temple created by mixing typical features of North Indian and South Indian architecture. The article traces the emergence of Vesara's conceptual logic in the eleventh century through architectural anomalies and daringly unprecedented play with the formal means of regional architecture, arguing that the makers of these temples exercised a level of inventiveness we have not been willing to credit them with so far.
Guarini and the Pursuit of Originality: The Church for Lisbon and Related Projects
Authors: Morrogh Andrew
Published: April 2006

With the aid of a drawing, published here for the first time, this article explores the genesis of Guarini's project for S. Maria della Divina Provvidenza, Lisbon, in the context of his other projects for large longitudinal churches and, more generally, of his methods of design. The churches show a completely new approach to the type, based on strongly projecting piers that produce a rhythmical flow in the main vista. In designing them, Guarini made much use of a grid, both to achieve simple arithmetical proportions, and for the projects' elaboration. As part of his scheme to develop a varied and highly original range of church types for publication, the large longitudinal churches show Guarini engaged in two characteristic creative strategies: that of taking ideas from his previous work and putting them in a new context; and that of setting out to produce an antithesis to a previous design. Guarini's organized creativity gives him a special place in baroque architecture.
The Shampay House of 1919: Authorship and Ownership
Authors: Park Jin-Ho , March Lionel
Published: April 2006

The Shampay House of 1919 has been commonly understood to be the very last of Frank Lloyd Wright's cruciform Prairie houses. It was planned to be erected in Beverly Hills, Illinois, but the client withdrew amid legal acrimony at the design stage. In this period, when Wright was frequently in Tokyo working on the Imperial Hotel and other commissions in Japan, Rudolph M. Schindler was left in charge of Wright's offices in the United States. While the Shampay House clearly comes out of Frank Lloyd Wright's studio, so that ownership of the design is not in question, this paper traces the controversy-between the two architects themselves as well as subsequent commentators-concerning the authorship of the project. The evidence presented unambiguously determines who conceived the design, the degree of Wright's involvement in its development, and the original contributions that Schindler brought to it. Previously unknown and unpublished blueprints and extracts from correspondence between Wright and Schindler are used extensively in the discussion.
Epstein‐Barr virus reactivation in a patient treated with anti‐thymocyte globulin for severe aplastic anemia
Authors: Calistri Elisabetta , Tiribelli Mario , Battista Marta , Michelutti Angela , Corbellino Mario , Viale Pierluigi , Fanin Renato , Damiani Daniela
Published: April 2006

Epstein‐Barr virus (EBV) infection and reactivation is an increasing complication in immune deficient patients, particularly after allogeneic hematopoietic stem cell transplantation (HSCT). Therapy with anti‐thymocyte globulin (ATG) is associated with higher incidence of EBV‐related disease in HSCT patients, but this risk is not documented in patients receiving ATG for severe aplastic anemia (SAA). We describe the case of a patient who developed an EBV infection, with the clinical features of an infectious mononucleosis, after immune suppression with cyclosporine and two courses of ATG for SAA. Am. J. Hematol. 81:355–357, 2006. © 2006 Wiley‐Liss, Inc.
Clustered incidence of acute promyelocytic leukemia during gefitinib treatment for non‐small‐cell lung cancer: Experience at a single institution
Authors: Matsuo Keitaro , Kiura Katsuyuki , Tabata Masahiro , Uchida Akiko , Hotta Katsuyuki , Niiya Daigo , Kubonishi Shiro , Ogino Atsuko , Fujiwara Yoshiro , Nakajima Hiromi , Shinagawa Katsuji , Ishimaru Fumihiko , Ueoka Hiroshi , Tanimoto Mitsune
Published: April 2006

Although gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, has been shown a significant activity for recurrent non‐small‐cell lung cancer (NSCLC), its long‐term adverse effect with its continuous usage has hitherto not been clearly elucidated. Subjects were 108 consecutive NSCLC cases who were treated with gefitinib between November 2001 and December 2004 at our single institution. A crude incidence rate ratio was calculated by ratio of crude incidence rate in our subject to population‐based incident rate of all leukemia (ICD: C91‐95) in the same region. The 95% confidence intervals (CIs) were calculated based upon a Poisson distribution. Three cases of acute promyelocytic leukemia (APL) occurred during gefitinib treatment, and these patients' past treatment histories are presented herein. No other malignancy was identified. All of the cases were diagnosed at the stage of mild‐to‐moderate cytopenia, especially thrombocytopenia, without disseminated intravascular coagulation. All presented a normal karyotype with positive PML‐RARα in RT‐PCR, indicating submicroscopic translocation. They responded well to APL treatments, including all‐trans‐retinoic acid. The crude incident rate ratio was 639.9 (95% confidence interval: 131.6–1,878.9, P < 0.0001) when the APL incidence in this cohort was compared to all leukemia cases in the general population in the same district in Japan. Thus we had three cases of secondary APL patients within the gefitinib‐treated NSCLC cohort. Although we cannot exclude an effect of past exposure of other cytotoxic agents and radiotherapy as a cause of APL, APL inducibility of gefitinib should be clarified in the further study. Am. J. Hematol. 81:349–354, 2006. © 2006 Wiley‐Liss, Inc.
Solid‐state IR–LD spectroscopic and theoretical analysis of arginine‐containing peptides
Authors: Kolev Tsonko
Published: April 2006

Structural prediction and IR‐characteristic bands assignment of arginine‐containing tri‐ and tetrapeptides glycyl‐glycyl‐arginine (GGArg) and glycyl‐glycyl‐arginyl‐alanine (GGArgAla) have been carried out, using linear‐dichroic infrared (IR–LD) spectroscopy of oriented solid‐samples in a nematic liquid crystal suspension. Spectroscopic data have been supported with ab initio analysis (Hartree–Fock level of theory and 6‐31++G** basis set). Predicted geometry parameters have been compared with known crystallographic ones of similar peptides, indicating a good correlation. © 2006 Wiley Periodicals, Inc. Biopolymers 83: 39–45, 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
Web‐based virtual torsion laboratory
Authors: Bhargava Peeyush , Antonakakis John , Cunningham Christine , Zehnder Alan T.
Published: April 2006

An emerging change across the science, technology, engineering, and mathematics curriculum is the implementation of online, or virtual laboratories as supplements or replacements to both homework assignments and laboratory exercises. To test the effectiveness of such labs, a web‐based virtual laboratory on the topic of torsion of engineered and biological materials was developed. The lab contains extensive data sets, videos of experiments, narrated presentations on lab practice and theory and assignments. Flexibility of use is built into the lab by providing the capability for the web‐pages to be tailored to the needs of a particular institution. The lab was implemented and evaluated in a standard, sophomore level statics, and strength of materials course. Results of the evaluation show that the virtual lab is clear, helped students with their understanding of torsion concepts, and offered a number of benefits. However students also rated hands‐on labs to be more fun and more interesting. © 2006 Wiley Periodicals, Inc. Comput Appl Eng Educ 14: 1–8, 2006; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20061
IMELS: An e‐learning platform for industrial engineering
Authors: Lau H. Y. K. , Mak K. L. , Ma Helen
Published: April 2006

An Interactive Multimedia E‐Learning System (IMELS) is developed to provide a comprehensive problem‐based learning environment for the discipline of industrial engineering. This article gives an overview of the design of this interactive multimedia e‐learning system that facilitates the interactive, web‐based teaching and learning of industrial engineering via a problem‐based learning paradigm. To demonstrate the functionality of the system, one of the case problems that is incorporated in the system—the performance of system analysis of a production operation of a “virtual company” is presented. Through this example, the article highlights the characteristics of the system provides and discusses the significance of the features delivered by the IMELS. © 2006 Wiley Periodicals, Inc. Comput Appl Eng Educ 14: 53–63, 2006; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20067
Enhanced Activity and Selectivity in Cyclohexane Autoxidation by Inert H‐Bond Acceptor Catalysts
Authors: Hermans Ive , Peeters Jozef , Jacobs Pierre A.
Published: April 2006

Herein, we demonstrate that the chain‐initiating dissociation of cyclohexyl hydroperoxide, CyOOH, is substantially accelerated by H‐bond acceptors (e.g. Teflon), which assist OO bond breaking by stabilising the leaving ⋅OH radical. This is a completely new approach to boost the chain‐propagating radical concentration. Indeed, up to now, literature has remained focussed on transition metal catalysis. In addition to this initiation effect, we demonstrate how inert perfluorinated compounds are also able to steer the selectivity at the molecular level, by promoting the conversion of the intermediate cyclohexyl hydroperoxide to the most desired end‐product, cyclohexanone. This effect is explained by an enhanced, H‐bond‐assisted, hydroperoxide propagation. This hitherto overlooked hydroperoxide propagation was recently presented by us as the dominant cyclohexanone and cyclohexanol source. We herein thus confirm our previously reported autoxidation scheme, and illustrate its usefulness as a solid basis for designing new catalytic systems.
Effect of word and syllable frequency on activation during lexical decision and reading aloud
Authors: Carreiras Manuel , Mechelli Andrea , Price Cathy J.
Published: April 2006

This functional MRI (fMRI) study investigated the effect of lexical and syllable frequency on visual word processing during lexical decision and reading aloud. Previous research has shown a dissociation of syllable and word frequency effects in Spanish using behavioral and electrophysiological measures, suggesting that sublexical (syllabic) representations are computed and mediate the firing of lexical candidates. Here, we characterize the neuroanatomical basis of these lexical and sublexical manipulations and their dependence on task. During lexical decision, words with low vs. high lexical frequency increased activation in left frontal, anterior cingulate, supplemental motor area (SMA), and pre‐SMA regions; while words with high vs. low syllable frequency increased activation in a left anterior inferior temporal region. In contrast, when the words were read aloud those with low vs. high syllable frequency increased activation in the left anterior insula, with no other significant effects. On the basis of the neuroanatomy, we propose that the contrasting effects of syllable frequency during lexical decision and reading aloud reflect two different cognitive processes in visual word processing. Specifically, words with high‐frequency syllables may increase lexical competition in the inferior temporal lobe while facilitating articulatory planning in the left anterior insula. Hum Brain Mapp, 2006. © 2006 Wiley‐Liss, Inc.
Self‐assembling peptides as injectable lubricants for osteoarthritis
Authors: Bell Carol J. , Carrick Lisa M. , Katta Jayanth , Jin Zhongmin , Ingham Eileen , Aggeli Amalia , Boden Neville , Waigh Thomas A. , Fisher John
Published: April 2006

The self‐assembly of peptides is explored as an alternative route towards the development of new injectable joint lubricants for osteoarthritis (OA). The versatility of the peptide chemistry allows the incorporation of behavior reminiscent of hyaluronic acid (HA), while the triggered in situ self‐assembly provides easy delivery of the samples by injection due to the low viscosity of the peptide solutions (that are initially monomeric). Using design criteria based on the chemical properties of HA, a range of de novo peptides were prepared with systematic alterations of charge and hydrophilicity that self‐assembled into nematic fluids and gels in physiological solution conditions. The frictional characteristics of the peptides were evaluated using cartilage on cartilage sliding contacts along with their rheological characteristics. Peptide P11‐9, whose molecular, mesoscopic, and rheological properties most closely resembled HA was found to be the most effective lubricant amongst the peptides. In healthy static and dynamic friction testing (corresponding to healthy joints) P11‐9 at 20–40 mg/mL performed similar to HA at 10 mg/mL. In friction tests with damaged cartilage (corresponding to early stage OA) P11‐9 was a less efficient lubricant than HA, but still the best among all the peptides tested. The results indicate that de novo self‐assembling peptides could be developed as an alternate therapeutic lubricant for early stage OA. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Enhanced DNA vaccine potency by mannosylated lipoplex after intraperitoneal administration
Authors: Hattori Yoshiyuki , Kawakami Shigeru , Lu Yan , Nakamura Kazumi , Yamashita Fumiyoshi , Hashida Mitsuru
Published: April 2006

Background

Here we describe a novel DNA vaccine formulation that can enhance cytotoxic T lymphocyte (CTL) activity through efficient gene delivery to dendritic cells (DCs) by mannose receptor‐mediated endocytosis.

Methods

Ovalbumin (OVA) was selected as a model antigen for vaccination; accordingly, OVA‐encoding pDNA (pCMV‐OVA) was constructed to evaluate DNA vaccination. Mannosylated cationic liposomes (Man‐liposomes) were prepared using cholesten‐5‐yloxy‐N‐{4‐[(1‐imino‐2‐D‐thiomannosylethyl)amino]butyl}formamide (Man‐C4‐Chol) with cationic lipid. The potency of the mannosylated liposome/pCMV‐OVA complex (Man‐lipoplex) was evaluated by measuring OVA mRNA in CD11c+cells, CTL activity, and the OVA‐specific anti‐tumor effect afterin vivoadministration.

Results

Anin vitrostudy using DC2.4 cells demonstrated that Man‐liposomes could transfect pCMV‐OVA more efficiently than cationic liposomes via mannose receptor‐mediated endocytosis.In vivostudies revealed that the Man‐lipoplex exhibited higher OVA mRNA expression in CD11c+cells in the spleen and peritoneal cavity and provided a stronger OVA‐specific CTL response than intraperitoneal (i.p.) administration of the conventional lipoplex and intramuscular (i.m.) administration of naked pCMV‐OVA, the standard protocol for DNA vaccination. Pre‐immunization with the Man‐lipoplex provided much better OVA‐specific anti‐tumor effect than naked pCMV‐OVA via the i.m. route.

Conclusions

These results suggested thatin vivoactive targeting of DNA vaccine to DCs with Man‐lipoplex might prove useful for the rational design of DNA vaccine. Copyright © 2006 John Wiley & Sons, Ltd.
Fecal cytokines and markers of intestinal inflammation in international travelers with diarrhea due to Noroviruses
Authors: Ko GwangPyo , Jiang Zhi‐Dong , Okhuysen Pablo C. , DuPont Herbert L.
Published: April 2006

The intestinal immune and inflammatory responses of Norovirus (NoV) are poorly defined. The objective of this study was to investigate fecal cytokine and lactoferrin profiles in response to NoV gastroenteritis in travelers. Both fecal cytokines and fecal lactoferrin were measured for NoV‐associated diarrhea (N = 7), mixed infection of NoV and enterotoxigenic E. coli (ETEC)‐associated diarrhea (N = 10) and in pathogen‐negative diarrhea cases (N = 19). Both IL‐2 and IFN‐γ were significantly increased in NoV‐associated diarrhea specimens, suggesting a predominant Th1 immune response to NoV infection in the gut. When a mixed infection of NoV and ETEC occurred, a combined Th1/Th2 response was observed suggesting a dual immune response secondary to infection by both pathogens. Intestinal inflammation associated with increased fecal lactoferrin, important in bacterial enteric infection, was not found in NoV‐associated gastroenteritis. J. Med. Virol. 78:825–828, 2006. © 2006 Wiley‐Liss, Inc.
Parametric Analysis of the Intermediate Concentration in a RAFT Polymerization and its Influence upon the Polymerization Kinetics
Authors: Butté Alessandro , Peklak A. David
Published: April 2006

Summary: A kinetic analysis of living/controlled radical polymerizations in bulk mediated by RAFT is presented. The main objective is to show how the kinetics of the RAFT process and, in particular, of the RAFT intermediate radical is affecting the overall polymerization rate. Namely, three different cases are analyzed: (i) slow fragmentation of the RAFT intermediate; (ii) cross‐termination of the RAFT intermediate with other radicals; and (iii) slow re‐initiation of the RAFT agent leaving group. Simplified analytical formulas are derived for the time‐dependent concentrations of the involved species as well as for conversion. They are supported by numerical simulations and are qualitatively compared to literature experimental findings. Criteria are also given to judge the influence of the RAFT reaction kinetic rate constants on the different phenomena observed experimentally in RAFT polymerization, namely inhibition and retardation. Since these criteria are given by using non‐dimensional groups, they can be readily applied to a broad spectrum of experimental conditions.

Logarithmic non‐dimensional concentration for the radicals (r) and intermediate radicals (q) versus the non‐dimensional polymerization time ($\tau$).

magnified image

Logarithmic non‐dimensional concentration for the radicals (r) and intermediate radicals (q) versus the non‐dimensional polymerization time ($\tau$).
Intensive extracorporeal photochemotherapy in pediatric patients with chronic graft‐versus‐host disease (cGVHD)
Authors: Duzovali Oznur , Chan Ka Wah
Published: April 2006

Extracorporeal photochemotherapy (ECP) is an alternative treatment approach in the management of chronic graft‐versus‐host disease (cGVHD). However, few reports have investigated the optimal treatment schedule of ECP. We treated seven pediatric patients with steroid‐resistant or ‐dependent cGVHD with ECP. Using the Therakos UVAR XTS system, ECP was begun three (three patients) or five (four patients) times a week initially. Complete and partial responses were obtained in three patients. Three of seven patients died of GVHD‐related complications. In this group initial intensive ECP did not improve the rate of response. However, this schedule appeared well tolerated. Pediatr Blood Cancer 2007;48:218–221. © 2006 Wiley‐Liss, Inc.
An easy and rapid method using microscopy to determine herbicide effects in Poaceae weed species
Authors: Hjorth Maibritt , Mondolot Laurence , Buatois Bruno , Andary Claude , Rapior Sylvie , Kudsk Per , Mathiassen Solvejg K , Ravn Helle W
Published: April 2006

A new, easy, rapid and relatively inexpensive method using microscopy has been developed for the detection of herbicide effects in leaves of grass weed species displaying no visual signs of damage. The method has potential to be used as a tool to indicate future death of grass species due to herbicide exposure by observing phytochemical effects, i.e. early‐warning effects. In the present study, Apera spica‐venti (L.) Beauv., Bromus hordeaceus L., Alopecurus myosuroides Huds., Lolium perenne L. and Poa annua L. were exposed to lethal rates of four herbicides with different mode of action. The herbicides investigated were the thiocarbamate: prosulfocarb, the sulfonylurea: iodosulfuron, the aryloxyphenoxypropionate: fenoxaprop‐P‐ethyl and the organophosphate glyphosate. Autofluorescence of leaves was studied under a microscope using ultraviolet and blue light. The fluorescence of leaves treated to enhance flavonoids was also examined. To confirm the results, microspectrofluorometry was performed. Effects indicating future death of the grasses were observed in visually healthy leaves following treatment with prosulfocarb, glyphosate and iodosulfuron. No changes were detected following treatment with fenoxaprop‐P‐ethyl. After exposure to glyphosate or iodosulfuron, changes in the content of flavonoids and other compounds with a conjugation system and rigid structure and a decrease in the content of chlorophyll were detected in the leaves. Prosulfocarb treatment resulted in changes in the content of flavonoids and other compounds with a conjugation system and rigid structure and an increase in the content of chlorophyll in the leaves. The results obtained from microspectrofluorometry indicated that exposure to prosulfocarb caused a reduction in the flavonoids quercetin, naringenin and/or naringin. Copyright © 2006 Society of Chemical Industry
Uncalibrated modelling of conservative tracer and pesticide leaching to groundwater: comparison of potential Tier II exposure assessment models
Authors: Fox Garey A , Sabbagh George J , Chen Wenlin , Russell Mark H
Published: April 2006

The Root Zone Water Quality Model (RZWQM) and Pesticide Root Zone Model (PRZM) are currently being considered by the Office of Pesticide Programs (OPP) in the United States Environmental Protection Agency (US EPA) for Tier II screening of pesticide leaching to groundwater (November 2005). The objective of the present research was to compare RZWQM and PRZM based on observed conservative tracer and pesticide pore water and soil concentrations collected in two unique groundwater leaching studies in North Carolina and Georgia. These two sites had been used previously by the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) Environmental Model Validation Task Force (EMVTF) in the validation of PRZM. As in the FIFRA EMVTF PRZM validation, ‘cold’ modelling using input parameters based on EPA guidelines/databases and ‘site‐specific’ modelling using field‐measured soil and hydraulic parameters were performed with a recently released version of RZWQM called RZWQM‐NAWQA (National Water Quality Assessment). Model calibration was not performed for either the ‘cold’ or ‘site‐specific’ modelling. The models were compared based on predicted pore water and soil concentrations of bromide and pesticides throughout the soil profile. Both models tended to predict faster movement through the soil profile than observed. Based on a quantitative normalised objective function (NOF), RZWQM‐NAWQA generally outperformed or was equivalent to PRZM in simulating pore water and soil concentrations. Both models were more successful in predicting soil concentrations (i.e. NOF < 1.0 for site‐specific data, which satisfies site‐specific applicability) than they were at predicting pore water concentrations. Copyright © 2006 Society of Chemical Industry
A Review of the bioactivity and potential health benefits of chamomile tea (Matricaria recutita L.)
Authors: McKay Diane L. , Blumberg Jeffrey B.
Published: April 2006

Chamomile (Matricaria recutita L., Chamomilla recutita L., Matricaria chamomilla) is one of the most popular single ingredient herbal teas, or tisanes. Chamomile tea, brewed from dried flower heads, has been used traditionally for medicinal purposes. Evidence‐based information regarding the bioactivity of this herb is presented. The main constituents of the flowers include several phenolic compounds, primarily the flavonoids apigenin, quercetin, patuletin, luteolin and their glucosides. The principal components of the essential oil extracted from the flowers are the terpenoids α‐bisabolol and its oxides and azulenes, including chamazulene. Chamomile has moderate antioxidant and antimicrobial activities, and significant antiplatelet activity in vitro. Animal model studies indicate potent antiinflammatory action, some antimutagenic and cholesterol‐lowering activities, as well as antispasmotic and anxiolytic effects. However, human studies are limited, and clinical trials examining the purported sedative properties of chamomile tea are absent. Adverse reactions to chamomile, consumed as a tisane or applied topically, have been reported among those with allergies to other plants in the daisy family, i.e. Asteraceae or Compositae. Copyright © 2006 John Wiley & Sons, Ltd.
A centralized approach to tandem mass spectrometry method development for high‐throughput ADME screening
Authors: Whalen Kevin , Gobey Jason , Janiszewski John
Published: April 2006

A centralized approach to acquisition and dissemination of tandem mass spectrometry (MS/MS) conditions within an ADME‐screening bioanalytical mass spectrometry group has been developed. The method development process uses two automated software products (Autoscan and Automaton) specifically designed for mass spectrometers manufactured by MDS Sciex. Both provide the ability to quickly determine selected reaction monitoring (SRM) transitions for hundreds of compounds per day. In addition, Autoscan determines optimal polarity and collision energy (CE). Automaton also determines the optimal declustering potential (DP) as well as the CE. The resulting optimized conditions are loaded into a central database for access by LC/MS/MS bioanalysis workstations in the group. The effect of DP and CE on the sensitivity was investigated. Optimization of DP improved signal response about 27% on average. For approximately 10% of compounds, signal enhancement was greater than 50% compared to the generic setting. A generic setting of DP = 25 V can be used for the majority of ADME‐screening applications. Optimization of CE can have a much larger impact on signal intensity and a minimum of three CE settings should be tested. We have determined that CE values of 1, 30 and 45 V provide adequate coverage for most small molecule drug discovery analytes. Copyright © 2006 John Wiley & Sons, Ltd.
Photocatalytic degradation of phenyl‐urea herbicides chlortoluron and chloroxuron: characterization of the by‐products by liquid chromatography coupled to electrospray ionization tandem mass spectrometry
Authors: Amorisco A. , Losito I. , Carbonara T. , Palmisano F. , Zambonin P.G.
Published: April 2006

The first stages of the photocatalytic degradation of the compounds chlortoluron [3‐(3‐chloro‐4‐methylphenyl)‐1,1‐dimethylurea] and chloroxuron [3‐[4‐(4‐chlorophenoxy)phenyl]‐1,1‐dimethylurea], belonging to the class of phenyl‐urea herbicides, were investigated using high‐performance liquid chromatography (HPLC) coupled to electrospray ionization ion trap tandem mass spectrometry (ESI‐IT‐MS/MS). Degradation was accomplished under solar radiation, using TiO2 embedded into a polyvinylidene fluoride (PVDF) transparent matrix as a heterogeneous photocatalyst. Aliquots of the chlorinated herbicide solutions were withdrawn at different times and subjected to gradient elution, reversed‐phase HPLC separations, specifically optimized to obtain the highest resolution between peaks related to the herbicide degradation by‐products. The latter were then investigated using MS detection; in particular, MS/MS measurements were made and structural information was obtained from the interpretation of fragmentation data. Several by‐products were identified; the most important ones are hydroxylated compounds arising from the interaction between the two chlorinated herbicides and OH radicals generated at the TiO2 surface under irradiation. Other by‐products were generated by slightly different processes, namely demethylation, dearylation and dechlorination, eventually followed by interaction with OH radicals. Copyright © 2006 John Wiley & Sons, Ltd.
Assessing the properties of internal standards for quantitative matrix‐assisted laser desorption/ionization mass spectrometry of small molecules
Authors: Sleno Lekha , Volmer Dietrich A.
Published: April 2006

Growing interest in the ability to conduct quantitative assays for small molecules by matrix‐assisted laser desorption/ionization (MALDI) has been the driving force for several recent studies. This present work includes the investigation of internal standards for these analyses using a high‐repetition rate MALDI triple quadrupole instrument. Certain physicochemical properties are assessed for predicting possible matches for internal standards for different small molecules. The importance of similar molecular weight of an internal standard to its analyte is seen through experiments with a series of acylcarnitines, having a fixed charge site and growing alkyl chain length. Both acetyl‐ and hexanoyl‐carnitine were systematically assessed with several other acylcarnitine compounds as internal standards. The results clearly demonstrate that closely matched molecular weights between analyte and internal standard are essential for acceptable quantitation results. Using α‐cyano‐4‐hydroxycinnamic acid as the organic matrix, the similarities between analyte and internal standard remain the most important parameter and not necessarily their even distribution within the solid sample spot. Several 4‐quinolone antibiotics as well as a diverse group of pharmaceutical drugs were tested as internal standards for the 4‐quinolone, ciprofloxacin. Quantitative results were shown using the solution‐phase properties, log D and pKa, of these molecules. Their distribution coefficients, log D, are demonstrated as a fundamental parameter for similar crystallization patterns of analyte and internal standard. In the end, it was also possible to quantify ciprofloxacin using a drug from a different compound class, namely quinidine, having a similar log D value as the analyte. Copyright © 2006 John Wiley & Sons, Ltd.
Global output feedback stabilization of upper‐triangular nonlinear systems using a homogeneous domination approach
Authors: Qian Chunjiang , Li Ji
Published: April 2006

This paper addresses the problem of global output feedback stabilization for a class of upper‐triangular systems with perturbing nonlinearities that are higher‐order in the unmeasurable states. A new design method based on the homogeneous domination approach and finite‐time stabilization technique is developed, which leads to global output feedback stabilizers for the upper‐triangular nonlinear systems under a homogeneous growth condition. A new perspective shown in this paper is that the finite‐time stabilization, in addition to its faster convergence rate, can also be utilized to handle control problems that were previously unresolved under asymptotic stabilization. Copyright © 2006 John Wiley & Sons, Ltd.
The impact of macroeconomic uncertainty on non‐financial firms' demand for liquidity
Authors: Baum Christopher F. , Caglayan Mustafa , Ozkan Neslihan , Talavera Oleksandr
Published: April 2006

This paper empirically investigates whether changes in macroeconomic volatility affect the efficient allocation of non‐financial firms' liquid assets. We argue that higher uncertainty will hamper managers' ability to accurately predict firm‐specific information and induce them to implement similar cash management policies. Contrarily, when the macroeconomic environment becomes more tranquil, each manager will have the latitude to behave more idiosyncratically as she can adjust liquid assets based on the specific requirements of the firm, bringing about a more efficient allocation of liquid assets. Our empirical analysis provides support for these predictions.
The stress tensor in a granular flow at high shear rates
Authors: Savage S. B. , Jeffrey D. J.
Published: April 2006

The stress tensor in a granular shear flow is calculated by supposing that binary collisions between the particles comprising the granular mass are responsible for most of the momentum transport. We assume that the particles are smooth, hard, elastic spheres and express the stress as an integral containing probability distribution functions for the velocities of the particles and for their spatial arrangement. By assuming that the single-particle velocity distribution function is Maxwellian and that the spatial pair distribution function is given by a formula due to Carnahan & Starling, we reduce this integral to one depending upon a single non-dimensional parameter R: the ratio of the characteristic mean shear velocity to the root mean square of the precollisional particle-velocity perturbation. The integral is evaluated asymptotically for R [Gt ] 1 and R [Lt ] 1 and numerically for intermediate values. Good agreement is found between the stresses measured in experiments on dry granular materials and the theoretical predictions when R is given the value 1·7. This case is probably the one for which the present analysis is most appropriate. For moderate and large values of R, the theory predicts both shear and normal stresses that are proportional to the square of the particle diameter and the square of the shear rate, and depend strongly on the solids volume fraction. A provisional comparison is made between the stresses predicted in the limit R → ∞ and the experimental results of Bagnold for shear flow of neutrally buoyant wax spheres suspended in water. The predicted stresses are of the correct order of magnitude and yield the proper variation of stress with concentration. When R [Lt ] 1, the shear stress is linear in the shear rate, and the analysis can be applied to shear flow in a fluidized bed, although such an application is not developed further here.
Effect of non-uniform currents and depth variations upon steady discharges in shallow water
Authors: Smith Ronald
Published: April 2006

When advection dominates diffusion, there are special directions (rays), distinct from but closely related to the contaminant flux vector, along which information is carried. The geometry of these ray paths is found to depend in a simple way upon the advection-diffusion vector ½u/D, where u is the flow velocity and D the cross-stream diffusivity. Simple models are used to show that for a steady point discharge the contaminant concentration is greatest in shallow water and towards the outside of bends.
Some effects of surface tension on steep water waves. Part 3
Authors: Hogan S. J.
Published: April 2006

This is the final part in the work on steady gravity–capillary waves by the author. On extending the work of Pierson & Fife (1961), the phenomenon of Wilton's ripples is resolved. These singularities of the traditional solution procedure are merely consequences of the non-uniformity in the ordering of the Fourier coefficients of the wave profile. Results presented here include wave properties and profiles. Near-resonant waves are also considered. Good agreement is found between this work and previous papers in the series as well as with other authors. An appendix contains all the results in numerical form. Minor algebraic errors in Wilton's original work are corrected.
Refraction of finite-amplitude water waves: deep-water waves approaching circular caustics
Authors: Peregrine D. H.
Published: April 2006

The ‘numerically exact’ properties of plane periodic deep-water waves are used in a slowly-varying-wave approximation for a steady axisymmetric wave field. The linear ‘ray’ theory for such a wave field corresponds to waves approaching a circular caustic. A parameter, C, characterizes each solution. If C is smaller than 20 the wave behaviour is dominated by the convergence of wave energy and waves are expected to break. Comparison with experiment for C = 0 indicates that breaking may be accurately predicted. If C is greater than 50 then the waves propagate closer to the caustic and, since it is of Peregrine & Smith's (1979) type R, it is likely that the waves do not break. These solutions show that wave action does not flow along the straight lines of the linear rays.
Particle motions near the bottom in turbulent flow in an open channel. Part 2
Authors: Sumer B. Mutlu , Deigaard Rolf
Published: April 2006

This study continues the investigation of particle motions near the bottom in a turbulent open channel flow, reported by Sumer & Oguz (1978; hereafter referred to as part 1). Paths of suspended heavy particles were recorded in three dimensions and in time, employing a stereo-photogrammetric system coupled with a stroboscope. In the case of smooth bottom, the measured kinematical quantities concerning the particle motions were found to be in accord with the available information on the ‘bursting process’. Agreement between the particle motion and the bursting process provided further support for the mechanism of particle suspension near the bottom proposed in part 1. Similar experiments were carried out when the bottom was rough. Comparison between the smooth- and rough-bottom cases could be made on the same basis as the flow Reynolds number as well as the particle properties were kept almost unchanged in both the smooth and rough boundary experiments. The observations showed that particle motions close to the rough bottom are very similar in character to those in the smooth-bottom case. The findings of the present paper suggested that the suspension mechanism given for the smooth-boundary flow could be extended to the rough-boundary case.
On the evolution of disturbances at an inviscid interface
Authors: Shankar P. N.
Published: April 2006

The initial-value problem for the evolution of the interface η(x, t) separating two unbounded, inviscid streams is considered in the framework of linearized analysis. Given the initial shape y = εη0(x) of the interface at t = 0 the objective is to calculate the interface shape η(x,t) for later times. First, it is shown that, if the vortex sheet is of infinite extent, if surface tension is absent and if the two streams are of the same density, the evolution is given by
\[
\eta(x,t) = \epsilon(1-\alpha)^{-1}{\rm Re}[\{(1-\alpha)+(1+\alpha)i\}\eta_0\{x-{\textstyle\frac{1}{2}}((1+\alpha)+(1-\alpha)i)t\}],
\]
where α (≠ 1) is the ratio of the speeds of the streams, provided the initial interface shape εη0(x) is analytic and its Fourier transform decays sufficiently rapidly. An interesting consequence is that it is possible, under certain circumstances, for the interface to develop singularities after a finite time. Next it is shown that when the two streams move at the same speed (α = 1) the growth of η is given by
\[
\eta(x,t) = \epsilon\eta_0(x-t)+\epsilon t\,d\eta_0(x-t)/dx
\]
with mild restrictions on η0(x). The major effect of surface tension, it is found, is to prevent the occurrence of singularities after a finite time, a distinct possibility in its absence. Finally the vortex sheet shed by a semi-infinite flat plate is considered. The unsteady mixed boundary-value problem is formally solved by using parabolic coordinates and Fourier-Laplace transforms.
Simultaneous temperature and velocity measurements in the plane of symmetry of a transitional turbulent spot
Authors: Antonia R. A. , Chambers A. J. , Sokolov M. , Atta C. W. Van
Published: April 2006

Simultaneous measurements of the longitudinal velocity U, normal velocity V, and temperature T have been made in turbulent spots generated in a slightly heated laminar boundary layer. The measurements were made in the plane of symmetry of the spot at several streamwise stations downstream of the spot-producing spark. Ensemble averages of U, V and T, obtained relative to the leading edge of the spot, are presented in terms of disturbances relative to the unperturbed values in the laminar flow. Ensemble-averaged disturbances of U, V and T in the outer part of the spot are consistent with a picture of a relatively large vortical structure with a spanwise vorticity in the same sense as that of the laminar flow. A rather dominant feature of these distributions is the large negative disturbance in V and U near the leading edge in the outer part of the spot; associated with this disturbance is a positive perturbation in T. The terms contributing to the ensemble-averaged values of UV, UT and VT are obtained and discussed. In the case of UV, contributions by the disturbance are found to be of the same order as those by the random turbulence superposed on the disturbance. For VT, the disturbance appears to play a more dominant role in the transfer of heat. The conical property of the spot is tested for disturbance temperature and velocity fields by comparing contours, at three streamwise stations, of the velocity and temperature disturbances using the co-ordinates introduced by Cantwell, Coles & Dimotakis (1978). The results show that the conical transformation, which was found to be a good approximation for the full velocity field, is not an accurate representation for the disturbance fields of velocity and temperature measured relative to laminar values. An alternative viscous transformation represents more accurately the disturbance fields. Features of the turbulence within the spot are compared with those obtained in a fully turbulent boundary layer.
Sound diffraction at a trailing edge
Authors: Rienstra S. W.
Published: April 2006

The diffraction of externally generated sound in a uniformly moving flow at the trailing edge of a semi-infinite flat plate is studied. In particular, the coupling of the sound field to the hydrodynamic field by way of vortex shedding from the edge is considered in detail, both in inviscid and in viscous flow.

In the inviscid model the (two-dimensional) diffracted fields of a cylindrical pulse wave, a plane harmonic wave and a plane pulse wave are calculated. The viscous proess of vortex shedding is represented by an appropriate trailing-edge condition. Two specific cases are compared, in one of which the full Kutta condition is applied, and in the other no vortex shedding is permitted. The results show good agreement with Heavens’ (1978) observations from his schlieren photographs, and confirm his conclusions. It is further demonstrated, by an explicit expression, that the sound power absorbed by the wake may be positive or negative, depending on Mach number and source position. So the process of vortex shedding does not necessarily imply an attenuation of the sound.

In the viscous model a high-Reynolds-number approximation is constructed, based on a triple-deck boundary-layer structure, matching the harmonic plane wave outer solution to a known incompressible inner solution near the edge, to obtain the viscous correction to the Kutta condition.
A discrete vortex method for the non-steady separated flow over an airfoil
Authors: Katz J.
Published: April 2006

A discrete vortex method was used to analyse the separated non-steady flow about a cambered airfoil. The foil flow modelling is based on the thin lifting-surface approach, where the chordwise location of the separation point is assumed to be known from experiments or flow-visualization data. Calculated results provided good agreement when compared with the post-stall aerodynamic data of two airfoils. Those airfoil sections differed in the extent of travel of the separation point with increasing angle of attack. Furthermore, the periodic wake shedding was analysed and its time-dependent influence on the airfoil was investigated.
Centrifugal instabilities during spin-down to rest in finite cylinders. Numerical experiments
Authors: Neitzel G. P. , Davis Stephen H.
Published: April 2006

A cylinder filled with a viscous, incompressible fluid is in an initial state of rigid-body rotation about its axis of symmetry. If the container is brought to rest impulsively, the resulting unsteady spin-down flow may be subject to sidewall instabilities due to an imbalance between centrifugal and pressure gradient forces. These instabilities are examined numerically using a finite-difference simulation to integrate the axisymmetric Navier–Stokes equations for a variety of aspect ratios and Reynolds numbers. The Taylor–Görtler vortex-wavelength spectrum, the torque and the angular momentum histories are calculated. Criteria for the onset time for instability and the spin-down time are given. The effects of the enhanced mixing due to instability on the spin-down characteristics and torque are discussed. The results are compared with experiment.
On mass transports generated by tides and long waves
Authors: Huthnance J. M.
Published: April 2006

For small-amplitude barotropic wave motion in a shallow fluid, Moore (1970) found that the associated mean mass transport is geostrophic, but otherwise arbitrary in the absence of friction. We show how weak friction, or starting the motion from rest, determines the mass transport by restricting circulation around closed geostrophic (f/h) contours. The resulting transport is quadratic in oscillatory quantities and depends on the friction type, but not on its (weak) magnitude. Comparison is made with earlier results in particular geometries. A tendency for anticyclonic circulation around shallow regions is found, and extends to large-amplitude oscillations where particle excursions exceed the topographic length scale. We suggest that numerical schemes for calculating tidal residuals should conserve mass and vorticity.
A numerical investigation into thermal instabilities in homeotropic nematics heated from below
Authors: Barratt P. J. , Sloan D. M.
Published: April 2006

This paper employs continuum theory to examine the onset of a particular type of cellular thermal instability in a sample of nematic liquid crystal confined between two infinite, horizontal flat plates when subjected to a vertical temperature gradient. We consider the case in which the anisotropic axis is initially uniformly aligned perpendicular to the plates. Using Chebyshev polynomials, accurate numerical solutions for the critical temperature gradient are obtained and the variation of this quantity with a uniform magnetic field applied vertically across the plates is investigated. In particular we obtain the value of the magnetic field at which the nature of the instability changes from an oscillatory type to a stationary one.