bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reducing the Impact of Missing Values in Factorial Experiments Arranged in Blocks
Authors: Godolphin J. D. 
Published: August 2006

AbstractThe loss of one or more observations during a designed experiment is a hazard well known to statistical practitioners, including practising engineers involved in product design and development. When observations are missing the eventual experimental design is necessarily altered from the design that was selected originally. This can introduce unwelcome difficulties, even though the available software may allow for missing values in the analysis of the surviving data. In particular, if missing values are incurred in a replicated factorial experiment arranged in blocks, the eventual design may be disconnected with respect to some factors under investigation and the experiment may be seriously damaged. It is suggested that the vulnerability of the original design should be examined at the planning stage of the experiment so that suitable action can be taken before any experimentation is done. These points are illustrated by considering an experiment consisting of three replicates of a full 23 factorial arranged in rows and columns and it is shown how to recognize the vulnerability of designs before the experimental process has taken place. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of aranidipine and its active metabolite in human plasma by liquid chromatography/negative electrospray ionization tandem mass spectrometry
Authors: Tian Lei , Jiang Juanjuan , Huang Yiling , Xu Li , Liu Hong , Li Yishi 
Published: August 2006

AbstractA simple, sensitive and rapid high‐performance liquid chromatography/negative electrospray ionization tandem mass spectrometry method was developed and validated for the assay of aranidipine (AR) and its active metabolite (AR‐M) in human plasma. Following a liquid‐liquid extraction, the analytes were separated using an isocratic mobile phase on a reversed‐phase column and analyzed by mass spectrometry in the multiple reaction monitoring mode using the respective [MH]− ions, m/z 387.0 → 164.0 for AR, m/z 389.1 → 208.1 for AR‐M and m/z 359.0 → 121.8 for the internal standard. The assay exhibited a linear dynamic range of 0.02–10 ng · mL−1 for AR and 0.2–100 ng · mL−1 for AR‐M in human plasma. The limits of quantitation were 0.02 ng · mL−1 for AR and 0.2 ng · mL−1 for AR‐M. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. A run time of 2.8 min for each sample exhibited its high‐throughout analysis ability. The validated method can be applied to analyze human plasma samples for pharmacokinetic studies. Copyright © 2006 John Wiley & Sons, Ltd.
Cloud point extraction combined with electrothermal vaporization inductively coupled plasma mass spectrometry for the speciation of inorganic selenium in environmental water samples
Authors: Chen Beibei , Hu Bin , He Man 
Published: August 2006

AbstractA new method based on cloud point extraction (CPE) separation and electrothermal vaporization inductively coupled plasma mass spectrometry (ETV‐ICPMS) detection has been proposed for the speciation of inorganic selenium in environmental waters. When the temperature of the system is higher than the cloud point temperature (CPT) of the selected surfactant Triton X‐114, the complex of Se(IV) with ammonium pyrrolidine dithiocarbamate (APDC) seems to be extracted into the surfactant‐rich phase, whereas the Se(VI) remains in aqueous solutions. Thus, an in situ separation of Se(IV) and Se(VI) could be realized. The concentrated analyte was introduced into the ETV‐ICP mass spectrometer for determination of Se((IV) after dilution with 200 µL methanol. Se(VI) was reduced to Se(IV) prior to determining total selenium, and its assay was based on subtracting Se(IV) from total selenium. The main factors affecting the CPE and the vaporization behavior of the analyte were investigated in detail. Under the optimized experimental conditions, the limit of detection (LOD) for Se(IV) was 8.0 ng/L with an enhancement factor of 39 when 10 mL of sample solution was preconcentrated to 0.2 mL. The relative standard deviation (RSD) was found to be 3.9% (CSe(IV) = 1.0 µg/L, n = 7). The proposed method was applied to the speciation of inorganic selenium in different environmental water samples with the recovery for the spiked samples in the range of 82–102%. Copyright © 2006 John Wiley & Sons, Ltd.
Desorption sonic spray ionization for (high) voltage‐free ambient mass spectrometry
Authors: Haddad Renato , Sparrapan Regina , Eberlin Marcos N. 
Published: August 2006

AbstractSonic spray ionization is shown to create a supersonic cloud of charged droplets able to promote efficient desorption and ionization of drugs directly from the surfaces of commercial drug tablets at ambient conditions. Compared with desorption electrospray ionization (DESI), desorption sonic spray ionization (DeSSI) is advantageous since it uses neither heating nor high voltages at the spray capillary. DeSSI therefore provides a more friendly environment in which to perform ambient mass spectrometry (MS). DeSSI‐MS is herein evaluated for the analysis of drug tablets, and found to be, in general, as sensitive as DESI‐MS. The (high) voltage‐free DeSSI method provides, however, cleaner mass spectra with less abundant solvent cluster ions and with enough abundant analyte signal for tandem mass spectrometry (MS/MS). These features may therefore facilitate the DeSSI‐MS detection of low molar mass components or impurities, or both. The higher‐velocity supersonic DeSSI spray also facilitates matrix penetration thus providing more homogenous sampling and longer lasting ion signals. Copyright © 2006 John Wiley & Sons, Ltd.
Predictive control of parabolic PDEs with state and control constraints
Authors: Dubljevic Stevan , El‐Farra Nael H. , Mhaskar Prashant , Christofides Panagiotis D. 
Published: August 2006

AbstractThis work focuses on predictive control of linear parabolic partial differential equations (PDEs) with state and control constraints. Initially, the PDE is written as an infinite‐dimensional system in an appropriate Hilbert space. Next, modal decomposition techniques are used to derive a finite‐dimensional system that captures the dominant dynamics of the infinite‐dimensional system, and express the infinite‐dimensional state constraints in terms of the finite‐dimensional system state constraints. A number of model predictive control (MPC) formulations, designed on the basis of different finite‐dimensional approximations, are then presented and compared. The closed‐loop stability properties of the infinite‐dimensional system under the low order MPC controller designs are analysed, and sufficient conditions that guarantee stabilization and state constraint satisfaction for the infinite‐dimensional system under the reduced order MPC formulations are derived. Other formulations are also presented which differ in the way the evolution of the fast eigenmodes is accounted for in the performance objective and state constraints. The impact of these differences on the ability of the predictive controller to enforce closed‐loop stability and state constraints satisfaction in the infinite‐dimensional system is analysed. Finally, the MPC formulations are applied through simulations to the problem of stabilizing the spatially‐uniform unstable steady‐state of a linear parabolic PDE subject to state and control constraints. Copyright © 2006 John Wiley & Sons, Ltd.
Systematization of approaches to adaptive boundary stabilization of PDEs
Authors: Krstic Miroslav 
Published: August 2006

AbstractWhile adaptive control of finite dimensional systems is an advanced field that has produced adaptive control methods for a very general class of LTI systems, adaptive control techniques have been developed for only a few of the classes of PDEs for which non‐adaptive controllers exist. We present a catalog of approaches for the design of adaptive controllers for PDEs controlled from a boundary and containing unknown destabilizing parameters affecting the interior of the domain. We differentiate between two major classes of schemes: Lyapunov schemes and certainty equivalence schemes. Within the certainty equivalence class, two types of identifier designs are pursued: passivity‐based and swapping designs. Each of those designs is applicable to two types of parametrizations: the plant model in its original form (which we refer to as the ‘u‐model’) and a transformed model to which a backstepping transformation has been applied (which we refer to as the ‘w‐model’). Hence, a large number of control algorithms result from combining different design tools—Lyapunov schemes, w‐passive schemes, u‐swapping schemes, etc.Our method builds upon the explicitly parametrized control formulae that we introduced in our earlier work on non‐adaptive backstepping control for PDEs. These formulae allow us to develop tunable controllers that avoid solving Riccati or Bezout equations at each time step.This paper is primarily a tutorial. Its purpose is to provide structure that helps the future reader of five other papers currently under review which contain the detailed proofs for the designs presented here. Additionally, the paper can serve as an entry point for a non‐expert reader interested in an introduction to adaptive boundary control of PDEs. For this reason, our presentation proceeds through a series of examples, which are generalized in the companion papers. Copyright © 2006 John Wiley & Sons, Ltd.
Presumptive adaptation and the effectiveness of knowledge transfer
Authors: Szulanski Gabriel , Jensen Robert J. 
Published: August 2006

AbstractAdaptation almost invariably accompanies the cross‐border transfer of firm‐specific practices. The existing literature contains two conflicting approaches to adaptation. The first, more traditional approach, following institutional, motivational, and pragmatic efficiency considerations, presumes that a modified practice can be fine tuned, stabilized, and institutionalized without consulting a working example and that practices should thus be adapted as quickly as possible to create fit with the local environment. The second approach argues, instead, for the need to maintain the diagnostic value of the original practice by adapting cautiously and gradually. In this paper, we report an in‐depth field investigation of the relationship between presumptive adaptation, adaptation that removes the diagnostic value of the original practice, and transfer effectiveness. The setting is the transfer of franchising knowledge across borders. We investigate how adherence to recommended practices affects the rate of network growth in the host country. We find that presumptive adaptation stalls network growth while a conservative approach to adaptation, which basically entails close adherence to the original practice, results in remarkably rapid network growth. We conclude that presumptive adaptation of knowledge assets could be detrimental to performance. Copyright © 2006 John Wiley & Sons, Ltd.
Highly Crystalline WO3 Thin Films with Ordered 3D Mesoporosity and Improved Electrochromic Performance
Authors: Brezesinski Torsten , Fattakhova Rohlfing Dina , Sallard Sébastien , Antonietti Markus , Smarsly Bernd M. 
Published: August 2006

AbstractWO3 thin layers with nanometer‐scale periodicity were prepared by evaporation‐induced self‐assembly (EISA) using a novel amphiphilic block‐copolymer template (poly(ethylene‐co‐butylene)‐block‐poly(ethylene oxide)). The evolution of the mesoporous ordered network and the crystallinity of the framework were monitored by 2D‐SAXS, WAXS, SEM, XPS, and porosimetry. By annealing the films, the pore‐wall crystallinity is adjusted between fully amorphous and highly crystalline without mesostructural degradation. Thus, the crystalline‐film framework is composed of phase‐pure monoclinic WO3 nanoparticles (12–14 nm in size). Furthermore, heat treatment transforms the originally spherical mesopores into ellipsoids, resulting in a unidirectionally shrunken, but still well‐defined and fully accessible bcc mesopore architecture. The influence of mesoporosity and crystallinity on electrochemical/electrochromic characteristics was addressed by monitoring electrochemical features and the absorption changes during Li insertion/extraction (repetitive potentiostatic cycling). Both the amorphous and crystalline mesoporous films possess electrochromic response times on the order of only seconds, which are attributable to the facilitated insertion of guest ions due to shortening of the diffusion path lengths. Also, the insertion/extraction reversibility of crystalline WO3 layers with 3D mesoporosity is improved compared to amorphous ones and reaches values close to 100 %.
Fetal urinoma: two new cases and a review of the literature
Authors: Gorincour G. , Rypens F. , Toiviainen‐Salo S. , Grignon A. , Lambert R. , Audibert F. , Garel L. , Fournet J.‐C. 
Published: August 2006

AbstractObjectiveTo evaluate the functional prognosis of kidneys affected prenatally by urinomas.MethodsThis was a retrospective review of cases of fetal urinoma reported in the literature, as well as two of our own cases.ResultsTwenty‐three patients with a prenatal diagnosis of urinoma (five bilateral) were included in the analysis. Postnatal ipsilateral renal function was observed in only six of the 28 renal units (i.e. around 20%).ConclusionsAlthough the precise causes of urinomas are still unknown, this review shows that in the event of a fetal urinoma, the probability of a non‐functional dysplastic ipsilateral kidney lies at around 80%. In‐utero puncture only appears to be justified in cases where fluid accumulation has mass effects on adjacent major structures. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Management of Kell isoimmunization — evaluation of a Doppler‐guided approach
Authors: Rimon E. , Peltz R. , Gamzu R. , Yagel S. , Feldman B. , Chayen B. , Achiron R. , Lipitz S. 
Published: August 2006

AbstractObjectiveTo assess the role of peak systolic velocity in the middle cerebral artery (MCA‐PSV) in the management of pregnancies complicated by Kell isoimmunization.MethodsSixteen fetuses were monitored by conventional protocol (Group 1) and eight fetuses by an MCA‐PSV‐guided protocol (Group 2). The conventional protocol included a weekly ultrasound evaluation and measurement of maternal anti‐Kell titers every 4–6 weeks. In Group 2 Doppler assessment of the MCA‐PSV was performed at intervals of 4 to 7 days and MCA‐PSV > 1.5 multiples of the median (MoM) was considered as an indication for fetal blood sampling (FBS).ResultsNo parameter emerged as a reliable predictor of isoimmunization severity in Group 1. In Group 2, no FBS was necessary in one case since the MCA‐PSV values obtained during the follow‐up were < 1.29 MoM. In two cases the first FBS was already indicated after 1 week of follow‐up, but five other fetuses were followed for 3–9 weeks before FBS was indicated. All fetuses with MCA‐PSV > 1.5 MoM prior to intrauterine transfusion (IUT) had severe fetal anemia on FBS. In fetuses with severe anemia on the first FBS, the MCA‐PSV values 7 days before the first FBS were < 1.29 MoM (four cases), between 1.29 and 1.5 MoM (two cases) and > 1.55 MoM (one case).ConclusionsIn the management of Kell isoimmunization invasive procedures may be avoided by implementing MCA‐PSV measurements. Delineation of appropriate intervals between reassessments, the reliability of MCA‐PSV following repeated IUTs, and cut‐off values for FBS await further study. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Understanding the key performance issues with MAC protocols for multi‐hop wireless networks
Authors: Iyer Aravind , Rosenberg Catherine 
Published: August 2006

AbstractMulti‐hop wireless networks arise in the context of ad hoc networks, sensor networks, and mesh networks, and their performance depends critically on the underlying medium access control (MAC) protocol. Inspite of the large body of work devoted to MAC protocols and associated problems, the relative importance of these problems is still not well understood. This is because most of the previous work focuses on designing a protocol to solve a particular problem, or on identifying scenarios where a protocol will not work well. In addition, most of the work is also based on simplistic assumptions about the physical wireless medium, like fixed ranges for communication and interference, or concepts like capture threshold where the desired signal strength is compared with interference from a single node at a time, rather than cumulatively.Our paper seeks to address these issues. We believe it is extremely critical that (i) we develop an understanding of the relative significance of the problems affecting MAC protocols, and that (ii) we use a realistic model for the physical channel for design and performance evaluation. Towards this end, we evaluate the performance of three currently proposed MAC protocols, IEEE 802.11 [1], RI‐BTMA [2], and DUCHA [3] under a realistic channel model with additive interference. Since these protocols solve or suffer from different sets of problems, our evaluation provides a differential diagnosis of the severity of these problems. Based on our observations, we propose a simple and robust two channel MAC protocol (entitled 2CM) that is based on IEEE 802.11 augmented with a busy‐tone channel. The 2CM protocol (i) mitigates the hidden node problem considerably, (ii) does not waste bandwidth in terms of logical control channels, and (iii) provides a reliable link layer acknowledgment. Through extensive simulations, we show that 2CM offers a consistently high throughput performance while not sacrificing link layer reliability in a variety of scenarios, thereby vindicating our approach. Copyright © 2006 John Wiley & Sons, Ltd.
Investigation of the block ACK scheme in wireless ad hoc networks
Authors: Li Tianji , Ni Qiang , Xiao Yang 
Published: August 2006

AbstractA Block Transmission and Acknowledgement (BTA) scheme, also called Block ACK, has been proposed in the IEEE 802.11e wireless local area networks (WLAN) specification to improve efficiency of the medium access control layer. The idea of the BTA scheme is to transmit multiple data frames followed by only one acknowledgement frame in a transmission block. In this paper, we present a theoretical model to evaluate the saturation throughput for the BTA scheme under error channel conditions in the ad hoc mode, validated with simulations. We show some advantages of BTA over the legacy MAC, and analyze how to select a proper number of frames for each transmission block. Results show that BTA is particularly effective in very high‐speed wireless networks, and it is important that the number of frames in each block is negotiated before transmissions to provide better efficiency. Copyright © 2006 John Wiley & Sons, Ltd.
Chemical speciation via X‐ray emission spectra
Authors: Ankudinov A. L. , Elam W. T. , Sieber J. R. , Rehr J. J. 
Published: August 2006

AbstractSince the early days of X‐ray spectrometry, X‐ray emission and fluorescence spectra have been used to investigate chemical speciation, e.g. the dependence on the formal oxidation state. Laboratory wavelength‐dispersive spectrometers have adequate resolution for these measurements. However, almost all studies have employed empirical methods to interpret the spectra. We aim to place such methods on a quantitative basis by means of efficient ab initio calculations of the X‐ray emission line shapes based on a self‐consistent, real‐space Green's function approach, as implemented in the X‐ray spectroscopy code FEFF8.2. Calculations are presented for the phosphorus K‐M2, 3, and the chromium L‐series emission lines for a selection of simple compounds. These lines exhibit changes depending on the oxidation state and on the neighboring atoms in the compounds that can be observed with instruments available in many XRF laboratories. The calculated spectra, as modified by convolution with a model monochromator response function, are compared with measured spectra. Simulated and measured spectra are found to be in reasonable agreement, and show that the approach has the potential to yield quantitative information about the chemical state. Copyright © 2006 John Wiley & Sons, Ltd.
Salicornia ramosissima population dynamics and tolerance of salinity
Authors: Silva Helena , Caldeira Gustavo , Freitas Helena 
Published: August 2006

AbstractField and greenhouse studies have been conducted to clarify aspects of population dynamics and NaCl tolerance of Salicornia ramosissima J. Woods. Two populations, Varela and Verdemilho, were monitored in the field during two consecutive life cycles and aspects of their morphology and density were recorded monthly. In the laboratory seedlings were exposed to different salinity for 10 weeks and growth and mortality rate were recorded weekly. The growth of the populations differed significantly, possibly because of the different salinities of the two sampling sites and/or genetic adaptations of the two populations to the environmental conditions. The absence of a significant correlation between sediment salinity and stem elongation suggested, however, that salinity, alone was not responsible for the differences observed and was possibly associated with other factors, because of nutritional, edaphic, and microclimatic conditions. S. ramosissima did not develop well in conditions of elevated or moderate salinity; its growth was optimum at low salinity. Optimum development of S. ramosissima may, nevertheless, depend on the total number of large seeds in a population seed bank, because of their greater success in germination and germinability under stress conditions than small seeds.
Biases in the estimation of spatial egg aggregation and association based on emergence data
Authors: Takahashi Kazuo H. 
Published: August 2006

AbstractSpatial aggregation and association of conspecific and allospecific eggs over resource patches have often been estimated based on emergence data. However, intra‐specific competition reduces the number of emergents of conspecifics, and inter‐specific competition reduces the number of emergents of allospecifics, causing biases in the estimation of spatial distribution of eggs using emergence data. The present study investigated, by laboratory experiments using drosophilids and simulation models, how the use of emergence data causes such biases. In the laboratory experiments, females were allowed to oviposit over resource patches, and spatial aggregation and association of eggs were examined. The number of emergents from each resource patch was then estimated from the density‐survival relationship, and spatial aggregation and association of emerging adults thus estimated were compared with those of eggs. In the simulation models, the spatial distributions of adults emerging from eggs that varied in their degree of spatial aggregation were evaluated under different intensities of intra‐ and/or inter‐specific competition. Both laboratory experiments and simulations indicate that the use of emergence data always causes an underestimation of spatial aggregation and association of eggs. Relaxation of intra‐ and inter‐specific competition by addition of extra resources would improve the estimation of spatial egg distribution based on emergence data.
Bipolar Transurethral Resection of the Prostate—A New Approach
Authors: Bishop Paula 
Published: August 2006

ABSTRACTBenign prostatic hyperplasia (BPH) is a common problem among older men. Transurethral resection of the prostate (TURP) is a common surgical procedure for treatment of BPH. Typically, TURP is performed using monopolar electric current and a wire electrode; however, the irrigating solution used during this procedure has the potential to cause transurethral resection (TUR) syndrome. A new technology uses bipolar electrosurgery, which creates less risk of electrical shock, and saline irrigation, which eliminates the risk for TUR syndrome. AORN J 77 (May 2003) 979–983.