bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of High‐Rate Clarification for Wet‐Weather‐Only Treatment Facilities
Authors: Jolis Domènec , Ahmad Meei‐Lih
Published: September 2006

High‐rate clarification (HRC) processes are well suited for enhanced primary treatment of wet‐weather flows in combined sewer systems. Suspended solids removal in excess of 75% of influent concentrations can be achieved consistently. Chemical oxygen demand and five‐day biochemical oxygendemand removal are better than 60%. However, although optimal treatment could be achieved in a matter of minutes when the units were started full, a delay of up to one‐half hour was observed when the units werestarted empty. Operational strategies that minimize this effect need to be developedin full‐scale tests before HRC processes can be implemented with confidence in wet‐weather‐only facilities.
Production of Polyhydroxyalkanoate During Treatment of Low‐Phosphorus‐Content Wastewater
Authors: Drnevich Maura A. , Noguera Daniel R.
Published: September 2006

To evaluate whether poly‐β‐hydroxyalkanoate (PHA) production and wastewater treatment could be combined in a single biological process, a bench‐scale sequencing batch reactor was operated with sequential anaerobic and aerobic stages and removal of excess sludge at different stages of treatment. The reactor treated synthetic wastewater with a high organic and low nutrient content, simulating industrial wastewater. Chemical oxygen demand removal efficiency was more than 90% in all cases. Poly‐β‐hydroxyalkanoate accumulation was significant, although it did not appear to be induced by oxygen limitations during the anaerobic stage. Sphaerotilus natans was apparently the dominant PHAaccumulating organism at the end of each reactor run and corresponded to a PHA accumulation of 16 to 20% of the total dry cell mass. Before S. natans dominated the reactors, PHA accumulation was approximately 17% when biomass was removed at the end of the aerobic stage and 6.6% when sludge removal also occurred during the anaerobic stage.
Denitrification of Nitrate Wastewater using Packed‐Bed Columns
Authors: Lee Lai Yoke , Ong Say Leong , Ng Wun Jern
Published: September 2006

Columnar packed‐bed (PB) reactors with a specific surface area of 127 m2/m3 were investigated in this study for treating nitrate wastewater. This study demonstrated that a single‐stage packed bed was able to achieve total nitrogen (TN) and chemical oxygen demand (COD) removal efficiencies higher than 83 and 75%, respectively. The highest achievable TN and COD removal rates were 47.2 g N/m2·d and 158.0 g COD/m2·d, respectively. The substrate removal rate in the PB column was found to follow half‐order reaction kinetics, with a reaction coefficient, k, of 53.62 (mg/L)1/2/d. A dual‐stage PB system was capable of achieving TN and COD removal efficiencies greater than 99 and 98%, respectively. Effluent TN and COD concentrations less than 6.5 mg NO3¯‐N/L and 50.0 mg COD/L, respectively, were obtained when the dual PB system was used.
Oxidation–Reduction Potential Changes in Aeration Tanks and Microprofiles of Activated Sludge Floc in Medium‐ and Low‐Strength Wastewaters
Authors: Li Baikun , Bishop Paul L.
Published: September 2006

Real‐time control of aeration tank operation is key to high‐efficiency pollutant removal and energy savings. One of the aims of this study was to examine the potential for using redox potential (oxidation–reduction potential [ORP]) to indicate wastewater quality online in aerationtanks treating medium (chemical oxygen demand [COD] of 70 to 150 mg/L) and low (COD of 15 to 30 mg/L) pollutant‐concentration wastewaters. The field‐scale data provide a good relationship between ORP values and nutrient removal along the length of the aeration tanks. The ORP values increaseddramatically as organic matter was removed along the aeration tanks, indicating the improvement of the bulk liquor redox status. Dissolved oxygen higher than 1.0 mg/L was necessary for good biodegradation and improvement of the liquid redox status. Nitrification occurred at higher ORP values(380 to 420 mV) than was the case for organic substrate oxidation (250 to 300 mV). The microprofiles obtained from microelectrode measurements substantiate the heterogeneity of the microbial processes inside activated sludge flocs. Because of microbial oxygen utilization, the aerobic regionin the activated sludge floc was limited to the top layer (0.1 to 0.2 mm) of the activated sludge aggregate present in medium‐strength wastewater, with an anoxic zone dominating inside the flocs. When dissolved oxygen in the bulk water was higher than 4.0 mg/L, the anoxic zone inside the flocdisappeared. At low wastewater pollutant concentrations, the ORP and dissolved oxygen inside the activated sludge aggregates were higher than those from medium‐strength wastewater. The prospect of using ORP as an online control approach for aeration tank operation and the potential reasonsfor activated sludge floc size varying with pollutant strengths are also discussed.
Carbon and Nutrient Removal from On‐Site Wastewater Using Extended‐Aeration Activated Sludge and Ion Exchange
Authors: Safferman Steven I. , Burks Bennette D. , Parker Robert A.
Published: September 2006

The need to improve on‐site wastewater treatment processes is being realized as populations move into more environmentally sensitive regions and regulators adopt the total maximum daily load approach to watershed management. Under many conditions, septic systems do not provide adequate treatment; therefore, advanced systems are required. These systems must remove significant amounts of biochemical oxygen demand (BOD) and suspended solids, and substantially nitrify, denitrify, and remove phosphorus. Many existing advanced on‐site wastewater systems effectively remove BOD, suspended solids, and ammonia, but few substantially denitrify and uptake phosphorus. The purpose of this research was to design and test modifications to an existing on‐site wastewater treatment system to improve denitrification and phosphorus removal. The Nayadic (Consolidated Treatment Systems, Inc., Franklin, Ohio), an established, commercially available, extended‐aeration, activated sludge process, was used to represent a typical existing system. Several modifications were considered based on a literature review, and the option with the best potential was tested. To improve denitrification, a supplemental treatment tank was installed before the Nayadic and a combination flow splitter, sump, and pump box with a recirculation system was installed after it. A recirculation pump returned a high proportion of the system effluent back to the supplemental treatment tank. Two supplemental treatment tank sizes, three flowrates, and three recirculation rates were tested. Actual wastewater was dosed as brief slugs to the system in accordance with a set schedule. Several ion‐exchange resins housed in a contact column were tested on the effluent for their potential to remove phosphorus. Low effluent levels of five‐day biochemical oxygen demand, suspended solids, and total nitrogen were achieved and substantial phosphorous removal was also achieved using a 3780‐L supplemental treatment tank, a recirculation ratio of 5:1, and a fine‐grain activated aluminum‐oxide‐exchange media. Good results were also obtained with an 1890‐L supplemental treatment tank and a recirculation ratio of 3:1. The most significant benefit of the supplemental treatment tank, in combination with the recirculation system, appears to be the low nitrogen concentration dosed to the Nayadic. By reducing the nitrogen concentration and spreading out its mass over time during no‐flow periods, the Nayadic's inherent low‐level denitrifying capacity was more closely matched and effective treatment was achieved.
Monitoring of Bacterial Morphology for Controlling Filamentous Overgrowth in an Ultracompact Biofilm Reactor
Authors: Lin H. , Ong S. L. , Ng W. J. , Khan E.
Published: September 2006

This research was part of a study of filamentous growth and control in an ultracompact biofilm reactor (UCBR). Morphologies of biofilm and filamentous bacteria in the UCBR were investigated. Ethanol was used as a substrate and sodium hypochlorite was applied as a toxicant to control filamentous growth. The results indicated that factors such as chemical oxygen demand, surface loading rate, pH, and dissolved oxygen could initiate filamentous overgrowth in the UCBR. Different biofilm and filamentous morphologies in the UCBR were observed under different operational conditions. Chlorination was an effective approach to control filamentous growth during and after biofilm formation. Proper chlorine dosing had no effect on biofilm, but killed filaments. Overdose of chlorine damaged biofilm and caused adverse effects such as low treatment efficiency, media clogging and washout, and biofilm color change in the reactor. Frequent monitoring of the morphologies of filaments and biofilm was needed during chlorination to prevent chlorine overdose.
MIMO multi‐periodic repetitive control system: universal adaptive control schemes
Authors: Dang H. , Owens D.H.
Published: September 2006

This paper presents a simple adaptive multi‐periodic repetitive control scheme when the MIMO LTI plant is not necessarily positive real (PR), however it is strictly minimum‐phase, the spectrum of high‐frequency gain matrixCBis symmetric and lies in the open right/left half complex plane(sign/spectrum definite). The non‐identifier‐based direct adaptive control technique, which does not need plant parameter information, is used to construct adaptive schemes and the system stability is analysed by Lyapunov second method. The extension to plant under certain non‐linear perturbations and an exponential stability scheme are also discussed. Finally, an adaptive proportional plus multi‐periodic repetitive control scheme is proposed. The theoretical findings are supported with simulations. Copyright © 2006 John Wiley & Sons, Ltd.
Repetitive control of synchronized operations for process applications
Authors: Ratcliffe James D. , Hätönen Jari J. , Lewin Paul L. , Rogers Eric , Owens David H.
Published: September 2006

Repetitive control (RC) algorithms for a plant, which contain pairs of complex conjugate poles at low frequency, resulting in a resonant system, is the subject area of this paper where the experimental results given are for a gantry robot and conveyor system in which the gantry is required to transfer payloads to a constant velocity conveyor by performing a repeating ‘pick and place’ operation. Initially, the gantry robot is controlled by means of a PID feedback controller in parallel with a proportional (P‐type) repetitive feed‐forward loop, while the conveyor operates under proportional feedback control. It is found that the RC system is unable to achieve long‐term performance. The performance degrades within a relatively small number of repetitions due to the build up of resonant frequencies in the learning loop. To prevent this, a batch aliasing technique, originally developed for iterative learning control, is modified to work in the RC framework, and is implemented in real‐time. The superior performance potential of the aliasing system is demonstrated experimentally. In the second part of this paper, multi‐machine systems, are considered where the critical new factor is the relative error between the conveyor and the robot. Here a second supervisory learning loop is proposed for use to shift the reference trajectory of one machine so that the relative placement error is also reduced. Again, supporting experimental results are given. Copyright © 2006 John Wiley & Sons, Ltd.
Cooperative control of multiple vehicles with limited sensing
Authors: Chen Jian , M. Dawson Darren , Salah Mohammad , Burg Timothy
Published: September 2006

A navigation function based cooperative control is developed in this paper for the navigation of multiple Unmanned Aerial Vehicles (UAVs) in the presence of known stationary obstacles and unknown enemy assets (EAs). Specifically, the motion of UAVs are planned in a centralized fashion. The standard navigation function approach is extended to a multiple navigation strategy with an analytical switch among different cases due to the limited sensing zone of the UAVs. A differentiable controller is proposed based on this navigation function that yields asymptotic convergence. A discussion for avoiding moving EAs is presented. Simulation results are provided to illustrate the performance of the proposed control strategy. Copyright © 2006 John Wiley & Sons, Ltd.
West Nile virus neuroinvasive disease
Authors: Davis Larry E. , DeBiasi Roberta , Goade Diane E. , Haaland Kathleen Y. , Harrington Jennifer A. , Harnar JoAnn B. , Pergam Steven A. , King Molly K. , DeMasters B. K. , Tyler Kenneth L.
Published: September 2006

Since 1999, there have been nearly 20,000 cases of confirmed symptomatic West Nile virus (WNV) infection in the United States, and it is likely that more than 1 million people have been infected by the virus. WNV is now the most common cause of epidemic viral encephalitis in the United States, and it will likely remain an important cause of neurological disease for the foreseeable future. Clinical syndromes produced by WNV infection include asymptomatic infection, West Nile Fever, and West Nile neuroinvasive disease (WNND). WNND includes syndromes of meningitis, encephalitis, and acute flaccid paralysis/poliomyelitis. The clinical, laboratory, and diagnostic features of these syndromes are reviewed here. Many patients with WNND have normal neuroimaging studies, but abnormalities may be present in areas including the basal ganglia, thalamus, cerebellum, and brainstem. Cerebrospinal fluid invariably shows a pleocytosis, with a predominance of neutrophils in up to half the patients. Diagnosis of WNND depends predominantly on demonstration of WNV‐specific IgM antibodies in cerebrospinal fluid. Recent studies suggest that some WNV‐infected patients have persistent WNV IgM serum and/or cerebrospinal fluid antibody responses, and this may require revision of current serodiagnostic criteria. Although there is no proven therapy for WNND, several vaccines and antiviral therapy with antibodies, antisense oligonucleotides, and interferon preparations are currently undergoing human clinical trials. Recovery from neurological sequelae of WNV infection including cognitive deficits and weakness may be prolonged and incomplete. Ann Neurol 2006;60:286–300
Characterization and expression of the Hex 110 gene encoding a glutamine‐rich hexamerin in the honey bee, Apis mellifera
Authors: Bitondi Márcia M.G. , Nascimento Adriana M. , Cunha Adriana D. , Guidugli Karina R. , Nunes Francis M.F. , Simões Zilá L.P.
Published: September 2006

An N‐terminal amino acid sequence of a previously reported honey bee hexamerin, HEX 110 [Danty et al., Insect Biochem Mol Biol 28:387–397 (1998)], was used as reference to identify the predicted genomic sequence in a public GenBank database. In silico analysis revealed an ORF of 3,033 nucleotides that encompasses eight exons. The conceptual translation product is a glutamine‐rich polypeptide with a predicted molecular mass of 112.2 kDa and pI of 6.43, which contains the conserved M and C hemocyanin domains. Semiquantitative and quantitative RT‐PCR with specific primers allowed for an analysis of mRNA levels during worker bee development and under different physiological conditions. Concomitantly, the abundance of the respective polypeptide in the hemolymph was examined by SDS‐PAGE. Hex 110 transcripts were found in high levels during the larval stages, then decreased gradually during the pupal stage, and increased again in adults. HEX 110 subunits were highly abundant in larval hemolymph, decreased at the spinning‐stage, and remained at low levels in pupae and adults. In 5th instar larvae, neither starvation nor supplementation of larval food with royal jelly changed the Hex 110 transcript levels or the amounts of HEX 110 subunit in hemolymph. In adult workers, high levels of Hex 110 mRNA, but not of the respective subunit, were related to ovary activation, and also to the consumption of a pollen‐rich diet. Arch. Insect Biochem. Physiol. 63:57–72, 2006. © 2006 Wiley‐Liss, Inc.
Mixture Models as a Method to Find Present and Divergent Genes in Comparative Genomic Hybridization Studies on Bacteria
Authors: Feten Guri , Almøy Trygve , Snipen Lars , Aakra Ågot , Nyquist O. Ludvig , Aastveit Are H.
Published: September 2006

Comparative genomic hybridization (CGH) using microarrays is performed on bacteria in order to test for genomic diversity within various bacterial species. The microarrays used for CGH are based on the genome of a fully sequenced bacterium strain, denoted reference strain. Labelled DNA fragments from a sample strain of interest and from the reference strain are hybridized to the array. Based on the obtained ratio intensities and the total intensities of the signals, each gene is classified as either present (one copy or multiple copies) or divergent (zero copies).

In this paper mixture models with different number of components are tted on different combinations of variables and compared with each other. The study shows that mixture models fitted on both the ratio intensities and the total intensities including the replicates for each gene improve, compared to previously published methods, the results for several of the data sets tested. Some summaries of the data sets are proposed as a guide for the choice of model and the choice of number of components.

The models are applied on data from CGH experiments with the bacteriaStaphylococcus aureusandStreptococcus pneumoniae. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ligand–DNA interaction in a nanocage of reverse micelle
Authors: Sarkar Rupa , Pal Samir Kumar
Published: September 2006

We have studied intercalation of ethidium bromide (EB) to genomic DNA encapsulated in a nanospace of an anionic AOT reverse micelle (RM). Circular dichroism (CD) study on the DNA in the RM reveals its condensed form. Here, we have used temporal decay‐associated spectra (DAS) and time‐resolved area normalized emission spectral (TRANES) techniques to investigate EB‐binding to condensed DNA because the interference of emission from unbound EB in the RM makes conventional steady state and picosecond resolved fluorescence spectroscopic techniques challenging. The binding affinity of the ligand EB with the DNA in the RM is found to increase with the size of the RM, reflecting the effect of lessening of DNA condensation on the binding affinity. CD spectra of the DNA in the RM with various sizes indicate the structural change of the condensed DNA with reverse micellar size. DAS and TRANES techniques along with dynamic light scattering studies of the EB‐DNA complex in the RM further reveal two kinds of binding modes of the ligand with the condensed DNA even in essentially monodispersed RMs. To investigate the role of RM on the ligand binding and secondary structure of the DNA, we have also studied complexation of EB with two synthetic self‐complimentary oligonucleotides of sequences (CGCAAATTTGCG)2 and (CGCGCGCGCGCG)2 in the RM. © 2006 Wiley Periodicals, Inc. Biopolymers 83: 675–686, 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
Allele frequency distributions of Apo B VNTR locus in Cukurova, Turkey
Authors: Yalin Erdinc , Attila Gulen , Yalin Serap , Aksoy Kıymet
Published: September 2006

The highly polymorphic minisatellites contain a variable number of tandemly repeated (VNTR) DNA sequences. They are extremely useful and informative markers to study genetic variation among human populations. We have analysed the allele frequency distribution at the highly polymorphic apolipoprotein B (Apo B) VNTR locus in order to obtain the population data for the Cukurova region in Turkey by using the polymerase chain reaction and polyacrylamide gel electrophoresis. We observed 10 different alleles and 21 genotypes in a sample of 100 unrelated individuals. The allele frequencies ranged from 0.01 to 0.4, with an expected heterozygosity of 0.69 for the Apo B locus. Alleles 37 (frequency = 0.4) and 35 (frequency = 0.17) were the most common in the Cukurova population. There was a significant deviation from the Hardy–Weinberg equilibrium (HWE) for genotype frequencies (χ2 = 29.12; df = 1; p = 0.000). This study possesses novelty as it is the first DNA polymorphism study conducted at the Cukurova population using an Apo B minisatellite locus. Copyright © 2006 John Wiley & Sons, Ltd.
Lysophosphatidylcholine promotes cholesterol efflux from mouse macrophage foam cells via PPARγ‐LXRα‐ABCA1‐dependent pathway associated with apoE
Authors: Hou Mengjun , Xia Min , Zhu Huilian , Wang Qing , Li Yan , Xiao Yongmei , Zhao Ting , Tang Zhihong , Ma Jing , Ling Wenhua
Published: September 2006

Formation of macrophage‐derived foam cells is a hallmark in earlier stages of atherosclerosis (AS). Increased cholesterol efflux from macrophage foam cells promote atherosclerotic regression. In the present study, lysophosphatidylcholine (LPC) promoting cholesterol efflux from macrophage foam cells was observed, and the mechanism underlying the action was investigated. Macrophage foam cells from mice were incubated with different concentrations of LPC (10, 20, 40, 80 µM), and the free cholesterol in medium increased but total intracellular cholesterol decreased. At the same time, the expression of PPARγ, LXRα, ABCA1 was enhanced in a dose‐dependent manner. The treatment of macrophage foam cells with 40 µM LPC for 12, 24 and 48 h promoted cellular cholesterol efflux in a time‐dependent manner, meanwhile expression of PPARγ, LXRα, ABCA1 was also raised respectively. Addition of different specific inhibitors of PPARγ (GW9662), LXRα (GGPP), ABCA1 (DIDS) to the foam cells significantly suppressed LPC‐induced cholesterol efflux. Also treatment with specific inhibitors of PPARγ or LXRα decreased ABCA1 mRNA and protein expressions. LPC (40 µM)‐induced cholesterol efflux was significantly lower in macrophage foam cells from apoE deficient mice than from normal C57BL/6J mice. In contrast, 10 µg apoAI‐induced cholesterol efflux from foam cells remained in apoE deficient mice. The present results indicate that LPC promotes cholesterol efflux from macrophage foam cells via a PPARγ‐LXRα‐ABCA1‐dependent pathway. Furthermore, apoE may be involved in this process. Copyright © 2006 John Wiley & Sons, Ltd.
Analysing the operation of the basic pass transistor structure
Authors: Nikolaidis Spiridon , Nikolaidis Theodoros
Published: September 2006

Pass transistor logic has become important for the design of low‐power high‐performance digital circuits due to the smaller node capacitances and reduced transistors count it offers. However, the acceptance and application of this logic depends on the availability of supporting automation tools, e.g. timing simulators, that can accurately analyse the performance of large circuits at a speed, significantly faster than that of SPICE based tools. In this paper, a simple and robust modelling technique for the basic pass transistor structure is presented, which offers the possibility of fast timing analysis for circuits that employ pass transistors as controlled switches. The proposed methodology takes advantage of the physical mechanisms in the pass transistor operation. The obtained accuracy compared to SPICE simulation results is sufficient for a wide range of input and circuit parameters. Copyright © 2006 John Wiley & Sons, Ltd.
Timing control for delay‐constrained data aggregation in wireless sensor networks
Authors: Li Hong , Yu HongYi , Yang BaiWei , Liu Ana
Published: September 2006

Timing control for delay‐constrained data aggregation is critical for improving the performance of a wireless sensor network. In this paper, we propose an adaptive timing control (ATC) mechanism to determine the proper time for data aggregation and forwarding. Given the maximum delay requirements of an application, the ATC mechanism determines the aggregation time for sensor nodes based on both the locations of the nodes and the number of children in the data aggregation tree. The nodes with more children are allocated a longer waiting time. The ATC mechanism maximizes the opportunity for data aggregation and ensures sufficient time to process data from the children. Analytical and simulation results show that the ATC mechanism leads to a higher data delivery rate and lower energy costs compared with existing similar algorithms. Moreover, since a lot of data packets can arrive at the sink earlier, the ATC mechanism is capable of responding more quickly to users. Copyright © 2006 John Wiley & Sons, Ltd.
A taxonomy of distributed query management techniques for wireless sensor networks
Authors: Chatterjea S. , Havinga P.
Published: September 2006

In the not too distant future, wireless sensor networks are envisioned to proliferate through the entire spectrum of the ‘environmental monitoring’ market allowing users to monitor a multitude of environments. Thousands or even millions of sensor nodes may span vast geographical areas enabling various environmental parameters to be monitored with significantly higher spatial and temporal resolutions than what is achievable using existing monitoring technologies. In order to manage the large amount of data that will be generated by these numerous sensor nodes, novel querying methods are needed to extract the required information in an energy‐efficient manner. This paper studies the techniques used to manage the queries in a distributed manner and classifies the current state‐of‐the‐art in this field into four main categories: in‐network processing, acquisitional query processing, cross‐layer optimization and data‐centric data/query dissemination. This taxonomy not only illustrates how query management techniques have advanced over the recent past, but also allows researchers to identify the relevant features when designing sensor networks for different applications. Copyright © 2006 John Wiley & Sons, Ltd.
Migration of immature mouse DC across resting endothelium is mediated by ICAM‐2 but independent of β2‐integrins and murine DC‐SIGN homologues
Authors: Wethmar Klaus , Helmus Yvonne , Lühn Kerstin , Jones Claire , Laskowska Anna , Varga Georg , Grabbe Stephan , Lyck Ruth , Engelhardt Britta , Bixel M. Gabriele , Butz Stefan , Loser Karin , Beissert Stefan , Ipe Ute , Vestweber Dietmar , Wild Martin K.
Published: September 2006

Immature dendritic cells (DC) reside in tissues where they initiate immune responses by taking up foreign antigens. Since DC have a limited tissue half‐life, the DC pool in tissues has to be replenished constantly. This implies that precursor/immature DC must be able to cross non‐activated endothelium using as yet unknown mechanisms. Here we show that immature, but not mature bone marrow‐derived murine DC migrate across resting endothelial monolayers in vitro. We find that endothelial intercellular adhesion molecule‐2 (ICAM‐2) is a major player in transendothelial migration (TEM) of immature DC, accounting for at least 41% of TEM. Surprisingly, the ICAM‐2‐mediated TEM was independent of β2‐integrins, the known ICAM‐2 ligands, since neither blocking of β2‐integrins with antibodies nor the use of CD18‐deficient DC affected the ICAM‐2‐specific TEM. In humans, the C‐type lectin DC‐specific ICAM‐3‐grabbing nonintegrin (DC‐SIGN) was shown to interact with ICAM‐2, suggesting a similar role in mice. However, we find that none of the murine DC‐SIGN homologues mDC‐SIGN, murine DC‐SIGN‐related molecule‐1 (mSIGN‐R1) and mSIGN‐R3 is expressed on the surface of bone marrow‐derived mouse DC. Taken together, this study shows that ICAM‐2 strongly supports transmigration of immature DC across resting endothelium by interacting with ligands that are distinct from β2‐integrins and DC‐SIGN homologues.
Synthesis and Some Properties of Bis(ruthenocenyl)thiophene Derivatives – Possible Spin‐Coupling in the Two‐Electron Oxidized Species of Dinuclear Ruthenocenes Bridged by Thiophene Derivatives
Authors: Sato Masaru , Kubota Yusuke , Tanemura Atsushi , Maruyama Genta , Fujihara Takashi , Nakayama Juzo , Takayanagi Toshiyuki , Takahashi Kenta , Unoura Kei
Published: September 2006

The binuclear ruthenocene derivatives bridged by thiophene, 3,4‐ethylenedioxythiophene, 2,2′‐bithiophene, thieno[3,2‐b]thiophene, or 3,6‐dimethylthieno[3,2‐b]thiophene were prepared by the Suzuki coupling of 2‐ruthenocenyl‐4,5‐tetramethyl‐1,3‐dioxaborolane with the corresponding diiodo compounds. In addition, thiophene‐ and bithiophene‐bridged binuclear pentamethylruthenocenes were prepared by the reaction of bis(pentamethylruthenocenyl)diyne and‐tetrayne with NaSH, respectively. The cyclic voltammogramsof these complexes exhibit one‐step two‐electron redox waves in the lower potential region (0–0.3 V versus FcH/FcH+). The two‐electron oxidized species of the thiophene‐bridged binuclear ruthenocene derivatives are comparatively stable and adopt the spin‐coupled and structurally isomerized fulvene complex‐type structure. The solid structure of the oxidized species of bis(pentamethylruthenocenyl)thiophene was determined by X‐ray diffraction analysis. The thieno[3,2‐b]thiophene‐bridged analog shows a temperature‐dependent 1H NMR spectrum in CD3NO2. The dicationic species exist as a RuII–RuIV mixed‐valence species in CD3CN.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A Binuclear Isocyanide Azadithiolatoiron Complex Relevant to the Active Site of Fe‐Only Hydrogenases: Synthesis, Structure and Electrochemical Properties
Authors: Hou Jun , Peng Xiaojun , Liu Jifeng , Gao Yunling , Zhao Xing , Gao Shang , Han Keli
Published: September 2006

An aromatic isocyanide‐substituted diiron complex5has been synthesized as a mimic for the active site of Fe‐only hydrogenases. Its structure has been fully characterized by X‐ray crystallography. The 4‐iodophenylisocyanide ligands in5are in the basal positions and are nearly parallel to each other, with π–π stacking interactions. Four isomeric geometries of complex5have been optimized by DFT calculations, and the electrochemical properties of5have been investigated by cyclic voltammetry in the absence and presence ofp‐toluenesulfonic acid (HOTs). Analysis of the cyclic voltammetric curve indicates that the reduction event at about–1.43 V is electrocatalytically active to proton reduction. This potential is more positive than that of any functionalized propanedithiolatodiiron complex. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Selective Phosphoramidite Cleavage as a Route to Novel Chiral and Achiral Pentacoordinated Nickel(II) PNP Pincer Complexes
Authors: Benito‐Garagorri David , Mereiter Kurt , Kirchner Karl
Published: September 2006

Treatment of NiBr2(DME) (DME = 1,2‐dimethoxyethane) or anhydrous NiBr2 with 2 equiv. of PNP pincer ligands featuring phosphoramidites in CH2Cl2 yields the novel neutral pentacoordinate complexes [Ni(PNP){κ1(P)‐R2P=O}Br]. Over the course of this reaction the P–N bonds of the phosphoramidite units of one PNP ligand are selectively cleaved due to hydrolysis affording an anionic κ1‐(P)‐coordinated phosphinite ligand [R2P=O]–, while a second PNP ligand remains intact and is coordinated in a κ3‐(P,N,P) fashion. The X‐ray structure of one [Ni(PNP){κ1(P)‐PR2=O}Br] complex has been determined.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Structural Studies of [CpMoL2(CO)2]+ (L = NCMe, L2 = 2,2′‐biimidazole) Complexes and Their Inclusion Compounds with Cyclodextrins
Authors: Pereira Cláudia C. L. , Braga Susana S. , Paz Filipe A. Almeida , Pillinger Martyn , Klinowski Jacek , Gonçalves Isabel S.
Published: September 2006

Protonation of [CpMo(η3‐C3H5)(CO)2] followed by addition of acetonitrile or 2,2′‐biimidazole (H2biim) gave the complexes [CpMo(NCMe)2(CO)2](BF4) (1) and [CpMo(H2biim)(CO)2](BF4) (2) in good yields. The structures of 1 and 2 were determined by single‐crystal X‐ray diffraction in the orthorhombic Pbca and triclinic P$\bar {1}$ space groups, respectively. Both complexes have similar metal ion coordination environments, which can be envisaged as slightly distorted pseudo‐square pyramids, a coordination geometry commonly compared with a four‐legged piano stool. The two complexes were immobilised in native and permethylated β‐cyclodextrins (β CD and TRIMEB) by methods tailored according to the stabilities and solubilities of the individual components and this gave four adducts with a 1:1 host/guest stoichiometry. The formation of true inclusion compounds was supported by powder X‐ray diffraction (XRD), thermogravimetric analysis (TGA), 13C{1H} CP/MAS NMR and FTIR spectroscopy. In the case of the TRIMEB adduct containing complex 1, the crystal packing arrangement is markedly similar to that previously reported for the corresponding 1:1 TRIMEB adducts of the neutral guests [CpMoX(CO)3] (X = Cl, CH2CONH2), featuring columns in which the macrocycles are arranged along the b axis in a tilted fashion.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Transformation of Esters into 2‐Substituted Allyl Halides via Tertiary Cyclopropanols: Application in the Stereoselective Synthesis of (2S,3S,7S)‐3,7‐Dimethyl‐2‐pentadecyl Acetate, the Sex Pheromone of the Pine Sawfly Neodiprion sertifer
Authors: Bekish Andrei V. , Prokhorevich Konstantin N. , Kulinkovich Oleg G.
Published: September 2006

(2S,3S,7S)‐3,7‐Dimethyl‐2‐pentadecyl acetate (ac‐1), the sex pheromone of the pine sawfly Neodiprion sertifer, has been newly synthesized by the transformation of the corresponding esters 8 and 12 into 2‐oxyalkyl‐substituted allyl bromides 4 and 5 via tertiary cyclopropanols 6 and 7. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Easily Accessible Chiral Imidazolinium Salts Bearing Two Hydroxy‐Containing Substituents as Shift Reagents and Carbene Precursors
Authors: Jurčík Václav , Gilani Mazhar , Wilhelm René
Published: September 2006

The behavior of new enantiopure imidazolinium salts bearing two hydroxy‐containing substituents as chiral shift reagents and as carbene precursors for diethylzinc addition to aldehydes is presented. The new hydroxy‐containing imidazolinium salts can be prepared in a few steps from amino alcohols and qualify as new tridentate ligands and ionic liquids.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Mannich and O‐Alkylation Reactions of Tetraalkoxyresorcin[4]arenes – The Use of Some Products in Ligand‐Assisted Reactions
Authors: Buckley Benjamin R. , Boxhall Jonathan Y. , Page Philip C. Bulman , Chan Yohan , Elsegood Mark R. J. , Heaney Harry , Holmes Kathryn E. , McIldowie Matthew J. , McKee Vickie , McGrath Matthew J. , Mocerino Mauro , Poulton Andrew M. , Sampler Edward P. , Skelton Brian W. , White Allan H.
Published: September 2006

The measurement of the pKa of racemic tetramethoxyresorcin[4]arenes explains the failure to obtain good yields in attempted Mannich reactions of these substrates under classical reaction conditions. The failure is related to the lack of adequate concentrations of the iminium ions that results from the reduced acid strength of tetraalkoxyresorcin[4]arenes compared with that of the parent octahydroxyresorcin[4]arenes. However, the preparation of a series of Mannich bases derived from racemic tetraalkoxyresorcin[4]arenes was accomplished under microwave‐assisted aprotic reaction conditions and the use of preformed iminium ion intermediates. When the reactions were carried out with the use of chiral bis(aminol) ethers, mixtures of diastereomers were obtained that could be separated by flash chromatography. The absolute configurations of the enantiomerically pure tetrabenzoxazine derivatives were established in some cases by X‐ray crystallographic analysis and by a comparison of the nuclear magnetic resonance spectroscopic data. The alkylation of racemic tetramethoxyresorcin[4]arenes was achieved with the use of an excess of 2‐bromo‐N‐[(R)‐(+)‐(α‐methylbenzyl)]acetamide in acetonitrile containing potassium carbonate. Enantioselective ligand‐assisted reactions of aromatic aldehydes are also reported with the use of dialkylzinc reagents both in the absence and in the presence of terminal alkynes.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
N‐Heterocyclic Carbene: An Efficient Catalyst for the Ring‐Opening Reaction of Aziridine with Acid Anhydride
Authors: Sun Xiaoyu , Ye Shengqing , Wu Jie
Published: September 2006

A N‐heterocyclic carbene serves as an efficient catalyst for the regioselective ring‐opening reactions of aziridines in the presence of acid anhydrides to afford the desired products in good to excellent yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
WTDWTR: What To Do With This Reaction? A New Program in the Field of Computer‐Aided Synthesis Design – Application to the Diels–Alder Reaction
Authors: Barone René , Attolini Mireille , Arbelot Michel , Chanon Michel
Published: September 2006

We present WTDWTR (What To Do With This Reaction?), which is a new program in the field of computer‐aided organic synthesis. WTDWTR tries to answer the question: what kind of structures can be obtained from a given reaction? We present the results that were obtained for the Diels–Alder reaction of structures that possess four fused rings of size 6, 6, 6 and 5 (“isomers” of the steroidal skeleton) for which WTDWTR generated 590 solutions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Total Synthesis of (+)‐Migrastatin
Authors: Reymond Sébastien , Cossy Janine
Published: September 2006

(+)‐Migrastatin, an antimetastatic agent, was synthesized by using three ruthenium‐catalyzed metathesis reactions: a ring‐closing metathesis (RCM) to control the (Z)‐trisubstituted double bond at C11–C12, another RCM at C6–C7 to establish the macrolactone core, and a cross‐metathesis to install the glutarimide side chain at C16–C17. The stereogenic centers at C9, C10, C13, and C14 were introduced by using two stereoselective crotylmetalations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Strategies of self‐regulation in goal attainment versus goal maintenance
Authors: Brodscholl Jeff C. , Kober Hedy , Higgins E. Tory
Published: September 2006

We propose that there exists an important difference between attainment and maintenance in terms of the goal pursuit strategies for which they call. Specifically, we propose that goal attainment calls for the use of eager approach strategies, whereas goal maintenance calls for the use of vigilant avoidance strategies. We distinguish between attainment versus maintenance as two different goal pursuit conditions on the one hand, and promotion versus prevention focus as two different self‐regulatory concerns on the other hand. We then use insights from Regulatory Fit Theory to make predictions concerning the interactive effects of these two motivational dimensions on outcome valuations. Consistent with our proposal about attainment and maintenance, we found that participants in a promotion focus valued the outcome of an attainment task more than did participants in a prevention focus, whereas the opposite was true for a maintenance task. Implications for maintenance‐related phenomena such as belief perseverance effects are subsequently discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Cholesterol‐rich membrane coatings for interaction studies in capillary electrophoresis: Application to red blood cell lipid extracts
Authors: Lindén Maria V. , Holopainen Juha M. , Laukkanen Antti , Riekkola Marja‐Liisa , Wiedmer Susanne K.
Published: September 2006

The purpose was to develop a stable biological membrane coating for CE useful for membrane interaction studies. The effect of cholesterol (chol) on the stability of dipalmitoylphosphatidylcholine (DPPC) and sphingomyelin (SM) coatings was studied. In addition, a fused‐silica capillary for CE was coated with human red blood cell (RBC) ghost lipids. Liposomes prepared of DPPC/SM with and without chol or RBC ghost lipids were flushed through the capillary and the stability of the coating was measured electrophoretically. Similar mixtures of DPPC/SM with and without chol were further studied by differential scanning calorimetry. The presence of phosphatidylcholine as a basic component in the coating solution of DPPC/SM/chol was found to be essential to achieve a good and stable coating. The results also confirmed the stability of coatings obtained with solutions of DPPC with 0–30 mol% of chol and SM in different ratios, which more closely resemble natural membranes. Finally, the electrophoretic measurements revealed that a stable coating is formed when capillaries are coated with liposomes of RBC ghost lipids.
Preparation and evaluation of C18‐bonded 1‐µm silica particles for pressurized capillary electrochromatography
Authors: Qu Qishu , Lu Xiao , Huang Xiaojing , Hu Xiaoya , Zhang Yukui , Yan Chao
Published: September 2006

Nonporous silica spheres (1 µm) were synthesized and bonded with octadecylsilane functionality. These stationary phase particles were packed electrokinetically into fused‐silica capillaries with 100 µm id for a length of 20 cm, which was evaluated by using pressurized CEC (pCEC). The efficiency of the C18 RP column was characterized through the theoretical plates of thiourea, benzyl alcohol, toluene, styrene, and naphthalene. The effects of experimental parameters such as the applied voltage, sample size, pump flow rate, pH value and the concentration of the buffer solution, and the content of methanol in the mobile phase, on‐column efficiency were evaluated. Column efficiency as high as 200 000 theoretical plates per meter for naphthalene was obtained with the optimal condition of 70% v/v methanol and 30% v/v of 10 mmol/L phosphate buffer (pH 7.8) at an applied voltage of 10 kV and a supplementary pressure of 500 psi.
Effect of barium tetraborate on the separation of tryptic digests of proteins by zone electrophoresis in uncoated capillaries
Authors: Mendieta Martha Elena , Antonioli Paolo , Righetti Pier Giorgio , Citterio Attilio , Descroix Stephanie , Sebastiano Roberto
Published: September 2006

A simple, fast, efficient and reproducible method for peptide separations in CZE is reported. It consists in running tryptic digests of peptides in an uncoated capillary, in a BGE composed of tetraborate as a buffering ion, in which the typical sodium counterion is substituted with barium. Efficient absorption of this divalent cation to ionized silanols and barium silicate precipitation seem to be able to shield effectively the silica surface from separands. This is demonstrated by the fact that, when tBa2+ ions are present in solution (from pH 8.5 up to pH 11.0), the electroendoosmotic flow is reversed; such reversal being progressively higher at higher pH values, by up to a four‐fold. Separations become progressively better at higher pH values, whereas at pH 11 in sodium tetraborate they are dramatically worsened. It is further hypothesized that the barium silicate layer further protects the silica surface against dissolution and corrosion which is quite substantial at pH 11.
Maximum‐likelihood estimation for multivariate spatial linear coregionalization models
Authors: Zhang Hao
Published: September 2006

A multivariate spatial linear coregionalization model is considered that incorporates the Matérn class of covariograms. An EM algorithm is developed for maximum‐likelihood estimation that has a few desirable properties and is capable of handling high‐dimensional data. Most estimates in the EM algorithm are updated through closed form expressions and these estimates automatically satisfy necessary constraints. The model and algorithm are illustrated through a real example. Copyright © 2006 John Wiley & Sons, Ltd.
Estimating the unknown change point in the parameters of the lognormal distribution
Authors: Jandhyala V. K. , Fotopoulos S. B.
Published: September 2006

We develop change‐point methodology for identifying dynamic trends in the parameters of a two‐parameter lognormal distribution. The methodology primarily considers the asymptotic distribution of the maximum likelihood estimate of the unknown change point. Among others, the asymptotic distribution enables one to construct confidence interval estimates for the unknown change point. The methodology is applied to identify changes in the monthly water discharges of the Nacetinsky Creek in the German part of the Ergebirge Mountains. Copyright © 2006 John Wiley & Sons, Ltd.
An info‐gap approach to power and sample size calculations
Authors: Fox David R. , Ben‐Haim Yakov , Hayes Keith R. , McCarthy Michael A. , Wintle Brendan , Dunstan Piers
Published: September 2006

Power and sample size calculations are an important but underutilised component of many ecological investigations. A key problem with these calculations is the need to estimate or guess the effect size and error variance (the design parameters) prior to the actual data collection. Furthermore, calculations associated with statistical power and sample size are invariably predicated on normal distribution theory. While the central limit theorem ensures the applicability of normal‐based inference for reasonably large sample sizes, the impact of violations of this assumed distributional form in the context of power and sample size determinations is rarely considered. This paper uses information‐gap theory to provide sample size guidelines that are robust to uncertainties associated with both the design parameters and distributional form. A simple information‐gap approach is developed for one‐ and two‐sided hypothesis tests. The model results quantify the extent to which minimum power demands can be protected from uncertainty by taking additional samples, and demonstrate the importance of the combined effects of standard deviation/effect size ratio and assumed distribution in these considerations. Info‐gap theory does not eliminate the need for an initial estimate or best guess of the design parameters or the specification of a parametric distribution from which to compute power. It does, however, measure the degree of insurance provided by additional samples in the face of uncertainties in each of these. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of specimen size and loading conditions on spalling of concrete
Authors: Boström Lars , Wickström Ulf , Adl‐Zarrabi Bijan
Published: September 2006

Different qualities of concrete have been fire tested using different geometries of the specimens as well as different load levels and load configurations. The main objective with the study was to examine a test methodology consisting of a full‐scale test and different small scale‐tests for determining the probability of spalling and the amount of spalling of fire exposed concrete structures. A reference specimen was defined as a one‐sided fire exposed slab with the dimensions 1800 × 1200 mm2 giving an exposed area of 1500 × 1200 mm2. A number of concrete qualities with different probabilities for spalling, were tested using the reference specimen. These tests showed that the reference specimens worked well giving the expected test results. Small specimens were manufactured in different shapes with the same concrete as the one used in the reference tests. These small specimens were tested either at the same time as the reference specimens in the large furnace or afterwards on a small‐scale furnace where the fire exposed surface was 450 × 360 mm2.

The test results clearly show the increased probability and the increased amount of spalling by using external compressive loading. The results also show that by using pre‐stress through bars or wires the load can be lost due to heating of the bars/wires which results in a decreased amount of spalling.

The boundary of the specimen also affects the amount of spalling. The spalling around the edges was in all tests less than the spalling on the central parts of the exposed area. It could also be noted that the spalling did not pass completely through any of the specimens. The reason for this is probably that the water/vapour could migrate out from the unexposed surface of the specimen. Copyright © 2006 John Wiley & Sons, Ltd.