bluuebunny/crossref_metadata_2025 huggingface dataset:
In‐situ spectroelectrochemical study of the growth process of a lead decanoate coating as corrosion inhibitor for lead surfaces
Authors: Dowsett Mark , Adriaens Annemie , Schotte Bart , Jones Gareth , Bouchenoire Laurence
Published: April 2009

We have monitored the growth of lead decanoate coatings in real time using electrochemical impedance spectroscopy (EIS) and synchrotron X‐ray diffraction in a unique environmental cell. The measurements involved the immersion of lead substrates in a 0.05 M sodium decanoate solution and the simultaneous collection of spectroscopic and electrochemical data as the coating deposits. In separate experiments, the surface morphology was investigated with SEM. The stratigraphy and thickness of layers after 6 h of treatment (≅1.5 µm) was determined using RBS and ultra low energy SIMS combined with surface profilometry. Weight‐gain measurements were also carried out. Overall, the results are consistent with an initially parabolic process, due simply to diffusionally limited two‐dimensional growth across the surface from nucleation sites. This becomes linear over time as one‐dimensional vertical growth sets in at full coverage (layer closure). The X‐ray data and the microscopy show that the coating consists of fine, interlocking, randomly oriented flake‐shaped crystals, with no obvious epitaxial relationship to the lead substrate. The growth rate of the coating and its corrosion resistance are extremely sensitive to preparation method of the NaC10 solution in ways which are still under investigation. Copyright © 2009 John Wiley & Sons, Ltd.
EIS study on passive films of AISI 304 stainless steel in oxygenous sulfuric acid solution
Authors: Lai Weiya , Zhao Wenzhen , Wang Feng , Qi Chengzhu , Zhang Jun
Published: April 2009

Electrochemical impedance spectroscopy (EIS) and Kramers–Kronig (K–K) transforms were made on American Iron and Steel Institute (AISI) 304 stainless steel (SS) in naturally aerated sulfuric acid solution at room temperature. The K–K relations testify that the systems under investigation comply with the linearity, causality, and stability constraints of linear system theory (LST) and thereby validate the EIS data. The polarization resistance decreased with removing of passive film and pitting formed in the passive layer, due to layer thinning or pitting caused by chloride. The impedance data for 304 SS with passive films can be accurately modeled using individual components of the equivalent circuits. The polarization resistances (Rp) of the 304 SS can be confirmed by Nyquist plots and estimated from the anodic polarization curves. The reaction model of the dissolution‐passivation process of 304 SS in acid solution is proposed. Copyright © 2009 John Wiley & Sons, Ltd.
Phenanthroline method for quantitative determination of surface carboxyl groups on carboxylated polystyrene particles with high sensitivity
Authors: Dai Jie , Liu Yanmei , Li Jun , Lu Ziyang , Yang Wensheng
Published: April 2009

This study developed a phenanthroline method for quantitative determination of surface carboxyl groups on carboxylated polystyrene (PS‐COOH) particles based on the coordination between the carboxyl groups and Fe2+. The ratio of the carboxyl groups, which is determined by conductometric titration method, to Fe2+ coordinated with the particles, which is determined by phenanthroline method, is 4.7, i.e. nCOOH = 4.7 × ΔnFe2+. The Lambert–Beer law is obeyed in the range of 0–60 × 10−9 mol/ml for the amount of surface carboxyl on the particles. The detection limit of the method is 2 nmol COOH/ml. The average standard deviation of the experiments is 4.4%. The relative deviation of the data obtained with this method is lower than 7% compared with that obtained with the conductometric titration method. The weight of the sample necessary for phenanthroline method is only about 0.1% of that necessary for conductometric titration method. It has been demonstrated that the phenanthroline method is suitable for quantitative determination of low amount of surface carboxyl groups on PS‐COOH particles due to its high sensitivity. Copyright © 2009 John Wiley & Sons, Ltd.
Measures of between‐cluster variability in cluster randomized trials with binary outcomes
Authors: Thomson Andrew , Hayes Richard , Cousens Simon
Published: April 2009

Cluster randomized trials (CRTs) are increasingly used to evaluate the effectiveness of health‐care interventions. A key feature of CRTs is that the observations on individuals within clusters are correlated as a result of between‐cluster variability. Sample size formulae exist which account for such correlations, but they make different assumptions regarding the between‐cluster variability in the intervention arm of a trial, resulting in different sample size estimates. We explore the relationship for binary outcome data between two common measures of between‐cluster variability: k, the coefficient of variation and ρ, the intracluster correlation coefficient. We then assess how the assumptions of constant k or ρ across treatment arms correspond to different assumptions about intervention effects. We assess implications for sample size estimation and present a simple solution to the problems outlined. Copyright © 2009 John Wiley & Sons, Ltd.
The k‐in‐a‐row up‐and‐down design, revisited
Authors: Oron Assaf P. , Hoff Peter D.
Published: April 2009

The percentile‐finding experimental design known variously as ‘forced‐choice fixed‐staircase’, ‘geometric up‐and‐down’ or ‘k‐in‐a‐row’ (KR) was introduced by Wetherill four decades ago. To date, KR has been by far the most widely used up‐and‐down (U&D) design for estimating non‐median percentiles; it is implemented most commonly in sensory studies. However, its statistical properties have not been fully documented, and the existence of a unique mode in its asymptotic treatment distribution has been recently disputed.

Here we revisit the KR design and its basic properties. We find that KR does generate a unique stationary mode near its target percentile, and also displays better operational characteristics than two other U&D designs that have been studied more extensively. Supporting proofs and numerical calculations are presented. A recent experimental example from anesthesiology serves to highlight some of the ‘up‐and‐down’ design family's properties and advantages. Copyright © 2009 John Wiley & Sons, Ltd.
Visualizing covariates in proportional hazards model
Authors: Karvanen Juha , Harrell Frank E.
Published: April 2009

We present a graphical method called the rank‐hazard plot that visualizes the relative importance of covariates in a proportional hazards model. The key idea is to rank the covariate values and plot the relative hazard as a function of ranks scaled to interval [0, 1]. The relative hazard is plotted with respect to the reference hazard, which can be, for example, the hazard related to the median of the covariate. Transformation to scaled ranks allows plotting of covariates measured in different units in the same graph, which helps in the interpretation of the epidemiological relevance of the covariates. Rank‐hazard plots show the difference of hazards between the extremes of the covariate values present in the data and can be used as a tool to check if the proportional hazards assumption leads to reasonable estimates for individuals with extreme covariate values. Alternative covariate definitions or different transformations applied to covariates can be also compared using rank‐hazard plots. We apply rank‐hazard plots to the data from the FINRISK study where population‐based cohorts have been followed up for events of cardiovascular diseases and compare the relative importance of the covariates cholesterol, smoking, blood pressure and body mass index. The data from the Study to Understand Prognoses Preferences Outcomes and Risks of Treatment (SUPPORT) are used to visualize nonlinear covariate effects. The proposed graphics work in other regression models with different interpretations of they‐axis. Copyright © 2009 John Wiley & Sons, Ltd.
A model selection approach to analysis of variance and covariance
Authors: Alber Susan A. , Weiss Robert E.
Published: April 2009

An alternative to analysis of variance is a model selection approach where every partition of the treatment means into clusters with equal value is treated as a separate model. The null hypothesis that all treatments are equal corresponds to the partition with all means in a single cluster. The alternative hypothesis correspond to the set of all other partitions of treatment means. A model selection approach can also be used for a treatment by covariate interaction, where the null hypothesis and each alternative correspond to a partition of treatments into clusters with equal covariate effects. We extend the partition‐as‐model approach to simultaneous inference for both treatment main effect and treatment interaction with a continuous covariate with separate partitions for the intercepts and treatment‐specific slopes. The model space is the Cartesian product of the intercept partition and the slope partition, and we develop five joint priors for this model space. In four of these priors the intercept and slope partition are dependent. We advise on setting priors over models, and we use the model to analyze an orthodontic data set that compares the frictional resistance created by orthodontic fixtures. Copyright © 2009 John Wiley & Sons, Ltd.
Direct Transdifferentiation of Stem/Progenitor Spermatogonia Into Reproductive and Nonreproductive Tissues of All Germ Layers
Authors: Simon Liz , Ekman Gail C. , Kostereva Natalia , Zhang Zhen , Hess Rex A. , Hofmann Marie-Claude , Cooke Paul S.
Published: April 2009

Pluripotent stem cells have great clinical potential for tissue regeneration/repair in humans. The use of embryonic stem (ES) cells is ethically controversial, leading to searches for other sources of pluripotent stem cells. Testicular spermatogonial stem cells (SSCs) produce the spermatogenic lineage. Under in vitro conditions, SSCs have the ability to give rise to pluripotent ES-like cells. We hypothesized that stem/progenitor spermatogonia could directly transdifferentiate into different tissue types if they were recombined with inductive mesenchymes from fetal/neonatal organs using a tissue separation/recombination methodology and grown in vivo. Green fluorescent protein transgenic mice were used to track cell lineages. Our results indicate that stem/progenitor spermatogonia recombined with the appropriate mesenchyme can directly transdifferentiate in vivo into tissues of all germ layers, including prostatic, uterine, and skin epithelium. In addition, transdifferentiated tissue expressed molecular, histological, and functional markers of the appropriate epithelium. The ability of stem/progenitor spermatogonia to directly generate various epithelia emphasizes their clinical potential, and if adult human SSCs have similar properties, this may have applications in human regenerative medicine.

Disclosure of potential conflicts of interest is found at the end of this article.
Notch Increases T/NK Potential of Human Hematopoietic Progenitors and Inhibits B Cell Differentiation at a Pro-B Stage
Authors: Benne Clarisse , Lelievre Jean Daniel , Balbo Michelle , Henry Adeline , Sakano Seiji , Levy Yves
Published: April 2009

Notch and its ligands regulate multiple cell fate decisions. However, several questions on the timing, durability, and reversibility of Notch signaling effects on human hematopoietic precursors are still unresolved. Here, we used recombinant Delta ligands to deliver temporally and dose-controlled signals to human immature cord blood CD34+CD38low cells at clonal cell levels. Notch activation increased the frequency of multipotent progenitors, skewed the T and natural killer (NK) cell potential of CD34+CD38low clones in a dose- and ligand-dependent manner, and inhibited the differentiation of B cell clones. Low doses of ligands were sufficient for significantly increasing the frequency of NK cell precursors, whereas higher doses were required for increasing the frequency of T-cell clones. Interestingly, we demonstrate that temporary Notch activation prevents the subsequent differentiation of CD34+CD38low cells beyond a pro-B CD79a+CD19− stage characterized as a common lymphoid progenitor (CLP). Moreover, the lymphoid potential of this pro-B/CLP was skewed toward NK cell potential while the B cell precursor frequency was dramatically reduced.

These results indicate critical timing and quantitative aspects of Notch/Delta interactions, imprinting the potential of CD34+CD38low hematopoietic progenitors. These results may have implications both in physiology and for cell manipulation because they demonstrate a tight regulation of the fate of human progenitors by Notch signaling. STEM CELLS 2009;27:1676–1685

Disclosure of potential conflicts of interest is found at the end of this article.
A systematic representation of path constraints for implicit path enumeration technique
Authors: Kim Tai Hyo , Bang Ho Jung , Cha Sung Deok
Published: April 2009

Accuracy of implicit path enumeration technique (IPET), which statically estimates the worst‐case execution time of a program using integer linear programming, relies on flow information captured as flow facts. Unfortunately, flow facts are inadequate for capturing complex and often subtle path constraints such as causalities. Manual annotation often introduces many disjunctions, and performance of IPET computation suffers significantly. This paper proposes a technique of encoding a subset of path constraints into flow facts. The technique has advantages over conventional approaches: (1) translation process is fully automated and (2) efficient IPET computation is possible because generated flow facts are compact in that they contain at most one disjunction. To demonstrate the effectiveness of our technique, a software tool was implemented to automatically generate flow facts for the subset of path constraints and case study has been conducted using public benchmark suites, GNU openSSH codes, and Korea multi‐purpose satellite (KOMPSAT‐1) software. Copyright © 2009 John Wiley & Sons, Ltd.
Development and experimental validation of automatic conversion procedure from mechanical to electrical connection for MEMS equivalent circuit
Authors: Fujiwara Nobuyo , Asami Kazuo , Iriye Yasuroh , Koike Tomoyuki , Tsuchiya Toshiyuki , Hashiguchi Gen
Published: April 2009

This paper describes equivalent circuit for micro electromechanical system (MEMS) using a type of behavior model for expressing mechanical and electromechanical element within circuit simulation, in order to simulate their dynamic behaviors easily. To fully treat the equivalent circuit as the behavior model, the equivalent interconnection expression for mechanical splice is required. In this work, a new approach has been proposed for converting the system composed of mechanical and electromechanical elements to equivalent circuit expression. This approach consists of substitution of unit equivalent elements and conversion of each equivalent interconnection for mechanical splices. We applied graph theory for equivalent interconnection. With this approach, complex MEMS consisting of a number of transducers and mechanical elements can be easily converted into equivalent circuits. In order to validate this approach, the resonant property of electrostatic comb‐drive actuator was simulated using the equivalent circuit generated and measured experimentally. The simulated resonant frequency was in good agreement with the measurement and the admittance characteristics were well described using this circuit with a consideration of coupling capacitances at the comb electrodes. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Development of µGC (micro gas chromatography) with high performance micromachined chip column
Authors: Nishino Masanori , Takemori Yusuke , Matsuoka Satoshi , Kanai Masaki , Nishimoto Takahiro , Ueda Masahito , Komori Kyoichi
Published: April 2009

A micro gas chromatography (µGC) instrument applying a high performance chip column fabricated on a silicon wafer was developed. Experimental results of the chip column and protyping of a µGC instrument are described. Approximately 35 000 theoretical plates were generated with the chip column coated liquid phase (5% phenyl‐/95% dimethyl‐polysiloxane). The theoretical plates of the chip column were close to those of the capillary column. Experimental minimum height equivalent to a theoretical plate (HETP, Hmin) of the chip column was 1.2 times higher than the calculated Hmin. A prototype µGC applying the chip column was developed. The µGC generated approximately 35 000 theoretical plates, similar to the theoretical plates obtained by a commercial GC instrument. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
A constant DC voltage control based compensation method of an active power quality compensator for electrified railways
Authors: Tanaka Toshihiko , Ishikura Norio , Hiraki Eiji
Published: April 2009

This paper proposes a novel and simple control method for the active power quality compensators (APQCs) used in electrified railways. The proposed method uses only the constant dc capacitor voltage control block, which is commonly used in the APQCs. No detection blocks of the harmonic, reactive, and negative‐sequence components are necessary. Thus we offer the simplest way to compensate the harmonic, reactive, and negative‐sequence currents on the primary side of the Scott transformer in the traction substation. The basic principle of the proposed control method is discussed in detail, and then confirmed by digital computer simulation usingPSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that the balanced source currents with the unity power factor are obtained on the primary side with the proposed control method, which uses only the constant dc capacitor voltage control. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Economic evaluation of offshore wind power in the liberalized Dutch power market
Authors: Chang Junying , Ummels Bart C. , van Sark Wilfried G.J.H.M. , den Rooijen Huub P.G.M. , Kling Wil L.
Published: April 2009

The variability and limited predictability of wind power challenges the operation of power systems, where the generation and load are required in balance at all times. The transmission system operator (TSO) is the responsible party. In a liberalized energy sector, key technical elements of power system operation have been transferred to markets and are thereby translated into economic responsibilities born by all system parties. The Dutch TSO TenneT operates the 15 min interval real‐time system balancing the market platform where energy responsibilities are economically assessed. Market parties subject to programme responsibilities with wind power as part of their generation portfolio must bear the integration costs of wind power's variability and forecast errors. The question arises what the real value of wind power is in the market. In this paper, a straightforward approach is used for the economic evaluation of existing wind power, taking Dutch market as a case study. Factual production data are obtained from a 108 MW offshore wind farm. Two variations of persistence forecast model are applied for the assessment of wind power value, which is quantified using price data on the Dutch wholesale markets and the TSO's balancing market. It is found that presently in The Netherlands, wind power is a price‐taker with a value equalling 90–110% of averaged market prices, including the imbalance cost component. The right‐skewed distribution of APX (Amsterdam Power eXchange) spot market prices is found to reduce the market value of wind power. The impact of forecast errors on overall wind power value is low due to the small impact of wind power on short‐term wholesale market prices. Copyright © 2009 John Wiley & Sons, Ltd.
Identification of aerosol particle sources in semi‐rural area of Kwabenya, near Accra, Ghana, by EDXRF techniques
Authors: Aboh Innocent Joy Kwame , Henriksson Dag , Laursen Jens , Lundin Magnus , Ofosu Francis Gormon , Pind Niels , Selin Lindgren Eva , Wahnström Tomas
Published: April 2009

Small aerosol particles have for a long time been known to be harmful to humans, and are today regarded to cause a larger number of deaths than traffic accidents globally. Energy dispersive x‐ray fluorescence (EDXRF) is a well known method that has been used for identification of toxic as well as non‐toxic elements in the particles. The combination of elements will together with other information help to identify the sources and predict the effects of particles on environment and human health.

The present work was conducted in Kwabenya, a suburb of the capital Accra of Ghana, which is frequently exposed to Harmattan dust from the Sahara–Sahel region. In total 171 filters each of PM2.5 and PM(2.5–10) were collected during 1 year. Levels of elements, black carbon (BC) and mass, were determined for both particle sizes. Principal component analysis (PCA) was performed on the datasets from Harmattan and non‐Harmattan periods.

The daily average of PM10 was very high, 179 µg m−3 and the BC contents were 4 µg m−3. The presence of crustal elements was large in PM(2.5–10) as well as in PM2.5, and had a more than tenfold increase in PM(2.5–10) during the Harmattan period. Major characteristic elements for different sources were identified from correlation coefficients and regression analysis of the data. Sahara sand aerosol was the major source in both study periods, but influence from biomass burning, sea‐spray and metal industries was also observed. Copyright © 2009 John Wiley & Sons, Ltd.
First Mixed Alkaline Uranyl Molybdates: Synthesis and Crystal Structures of CsNa3[(UO2)4O4(Mo2O8)] and Cs2Na8[(UO2)8O8(Mo5O20)]
Authors: Nazarchuk Evgeny V. , Siidra Oleg I. , Krivovichev Sergey V. , Malcherek Thomas , Depmeier Wulf
Published: April 2009

Two new mixed alkaline uranyl molybdates CsNa3[(UO2)4O4Mo2O8] (1) and Cs2Na8[(UO2)8O8(Mo5O20)] (2) have been obtained by high‐temperature solid state reactions. Their crystal structures have been solved by direct methods: Compound 1: triclinic, P$\bar{1}$, a = 6.46(1), b = 6.90(1), c = 11.381(2) Å, α = 84.3(1), β = 91.91(1), γ = 80.23(1)°, V = 488.6(2) Å3, R1 = 0.06 for 2865 unique reflections with |Fo| ≥ 4σF; Compound 2: orthorhombic, Ibam, a = 6.8460(2), b = 23.3855(7), c = 12.3373(3) Å, V = 1975.2(1) Å3, R1 = 0.049 for 2120 unique reflections with |Fo| ≥ 4σF. The structure of 1 contains complex sheets of UrO5 pentagonal bipyramids and molybdenum polyhedra. The sheets have [(UO2)2O2(MoO5)] composition. Natrium and cesium atoms are located in the interlayer space. Cesium atoms are situated between the molybdenum clusters, whereas natrium atoms are segregated between the uranyl complexes. The large Cs+ ions are localized between the Mo2O9 groups and force the molybdenum polyhedra to rotate relative to the [(UO2)2O2(MoO5)] sheets. Such rotation is impossible for U6+ polyhedra due to their rigid edge‐sharing complexes. The distance between the U6+ polyhedra vertices of neighboring layers is 3.8 Å, that allows the Na+ ion to be positioned between the uranyl groups. The crystal structure of 2 is based upon a framework consisting of [(UO2)2O2(MoO5)] sheets parallel to (010). The sheets are linked into a 3‐D framework by sharing vertices with the Mo(2)O4 tetrahedra, located between the sheets. Each MoO4 tetrahedron shares two of its corners with two MoO6 octahedra in the sheet above, and the other two with MoO6 octahedra of the sheet below. Thus four MoO6 octahedra and one MoO4 tetrahedron form chains of composition Mo5O18. The resulting framework has a system of channels occupied by the Cs+ and Na+ ions.
Synthesis and Structural Characterization of ZnII α‐Diimine Complexes with Chloride and Thiocyanate Co‐Ligands
Authors: Ferreira Leonardo C. , Filgueiras Carlos A. L. , Visentin Lorenzo C. , Bordinhaõ Jairo , Hörner Manfredo
Published: April 2009

The preparation and spectroscopic and structural characterization of three ZnII complexes with bis[N‐(2,6‐dimethylphenyl)imine]acenaphthene, L1, and with bis[N‐(2‐ethylphenyl)imine]acenaphthene, L2, are decribed herein. Two of the complexes were prepared from ZnCl2 and the third from Zn(NCS)2. One‐pot reaction techniques were used, leading to high yields. The complexes were characterized by microanalysis, IR and 1H NMR spectroscopy, and single‐crystal X‐ray diffraction. The structures of the complexes are significantly different, with the chloride‐containing species forming distorted tetrahedra around the metal, whereas its thiocyanate analog is dimeric, with each metal at the center of a distorted square pyramid, with bridging and terminal [SCN]– ligands.
Synthesis, Single Crystal Structure Determination and Rietveld Refinement of Cadmium Tetrametaphosphimate Octahydrate Cd2(PO2NH)4·8H2O
Authors: Römer S. Rebecca , Schnick Wolfgang
Published: April 2009

Cd2(PO2NH)4·8H2O crystallizes in space group P21/c (no. 14), Z = 2, with a = 648.5(2), b = 1070.5(2), c = 1328.7(3) pm and β = 103.11(3) °. The structure, isotypic with M2(PO2NH)4·8H2O (M = Mg, Mn, Co, Ni, Zn), is composed of Cd2+ and (PO2NH)44− ions as well as crystal water molecules. The P4N4 rings of the (PO2NH)44− ions exhibit a slightly distorted chair‐2 conformation, which has been described by torsion angles, displacement asymmetry parameters and puckering parameters. The tetrametaphosphimate anions are connected forming layers. These layers are linked solely by hydrogen bonds, forming a three‐dimensional network.
Novel Octahedral Bis[2‐(1‐aziridinyl)ethanol‐κ2N,O] Complexes of Cobalt(II)
Authors: Putzien Sophie , Wirth Stefan , Roedel J. Nicolas , Lorenz Ingo‐Peter
Published: April 2009

The synthesis and molecular structure of trans‐{bis[(acetato‐κO)‐(2‐(1‐aziridinyl)ethanol‐κ2N,O)]}cobalt(II) (4) and cis‐{bis[chlorido‐(2‐(1‐aziridinyl)ethanol‐κ2N,O)]}cobalt(II) (5) is reported. Both neutral chelate complexes are prepared from the corresponding CoII salt [CoX2; X = OAc (1), Cl (2)] and 2‐(1‐aziridinyl)ethanol (azolH, 3) in dry dichloromethane. A third, ionic complex, cis‐{bis[aqua‐(2‐(1‐aziridinyl)ethanol‐κ2N,O)]}cobalt(II) diacetate (6) is formed from 4 in the presence of water and could be crystallized from aqueous dichloromethane. In all cases, 2‐(1‐aziridinyl)ethanol is coordinating as bidentate chelate ligand by the nitrogen and oxygen atom of the aziridinyl and hydroxy moiety. After purification, the compounds have been fully characterized using IR spectroscopy and FAB+‐MS. The single‐crystal X‐ray structure analysis revealed a distorted octahedral geometry for all complexes with either trans (4) or cis (5, 6) configuration.
New Ternary Silicide LiRh2Si2 – Structure and Bonding Peculiarities
Authors: Dinges Tim , Rodewald Ute C. , Matar Samir F. , Eckert Hellmut , Pöttgen Rainer
Published: April 2009

The silicide LiRh2Si2 was synthesized from the elements in a sealed niobium ampoule and was characterized by X‐ray powder and single‐crystal diffraction: FeMo2B2 type (ordered version of U3Si2), P4/mbm, a = 698.1(5), c = 274.6(4) pm, wR2 = 0.0842, 186 F2 values and 11 variables. The rhodium and silicon atoms build up a covalently bonded three‐dimensional [Rh2Si2] network (244–248 pm Rh–Si), in which the lithium atoms fill larger channels which extend along the c axis. A similar structural arrangement occurs in LiY2Si2, however, the strong difference in size between rhodium and yttrium leads to different distortions. LiRh2Si2 and LiY2Si2 are isopointal rather than isotypic. The crystal chemistry and bonding peculiarities of both silicides are discussed on the basis of ab initio electronic structure calculations. 7Li solid‐state NMR studies on LiRh2Si2 revealed restricted motional narrowing due to lithium atomic diffusion in the temperature range 170–450 K.
Synthesis and Structural Characterization of the Tetrakis(methimazolyl)borates Li[Bmt4] and [Ru(p‐cymene)(Bmt4)][PF6]
Authors: Kunz Kerstin , Bolte Michael , Wagner Matthias , Lerner Hans‐Wolfram
Published: April 2009

The lithium tetrakis(methimazolyl)borate, Li[Bmt4], is accessible from the reaction of Li[BH4] with four equivalents of methimazole. The crystal structure of Li[Bmt4] supported by four water molecules is described. Reaction of Li[Bmt4] with [Ru(p‐cymene)Cl2]2 and subsequent treatment with NH4PF6 in CH3CN results in the formation of the complex [Ru(p‐cymene)(Bmt4)][PF6]. In addition, we report the result of the X‐ray structure analysis of the chiral Ru complex [Ru(p‐cymene)(Bmt4)][PF6].
Silylated Tetrazoles and Triazoles
Authors: Gronde Ingo , Mitzel Norbert W.
Published: April 2009

1‐Dimethysilyltetrazole (1) has been prepared from 1H‐tetrazole and chlorodimethylsilane in the presence of 2,6‐lutidine, bis(1‐tetrazolyl)dimethylsilane (2) from the reaction of 1H‐tetrazole, dimethyldichlorosilane and triethylamine and 5‐(trimethylsilylamino)‐1H‐tetrazole (3) from 5‐amino‐tetrazole monohydrate and hexamethyldisilazane. The reactions of 4‐amino‐1H‐1,2,4‐triazole with different amounts of hexamethyldisilazane gave rearrangement reactions yielding 1‐trimethylsilyl‐3‐(trimethylsilyl)amino‐1,2,4‐triazole (4) and 1‐trimethylsilyl‐3‐bis(trimethylsilyl)amino‐1,2,4‐triazole (5). The compounds were characterised by NMR spectroscopy (1H, 13C{1H} and 29Si NMR), by IR spectroscopy, mass spectrometry, elemental analyses and in the case of 3, 4 and 5 by determination of their crystal structures by X‐ray diffraction. The structure of a cocrystallisate of 4‐amino‐1H‐1,2,4‐triazole with acetonitrile was also determined. Common structural distortions of silylated ring nitrogen atoms are discussed as well as hydrogen bonding motifs in the crystal structures.
Nutritional Risk Factors in Planned Oncologic Surgery: What Clinical and Biological Parameters Should Be Routinely Used?
Authors: Antoun Sami , Rey Annie , Béal Jacqueline , Montange Fabienne , Pressoir Martine , Vasson Marie‐Paule , Dupoiron Denis , Gourdiat‐Borye Anne , Guillaume Alain , Maget Brigitte , Nitenberg Gérard , Raynard Bruno , Bachmann Patrick
Published: April 2009

Background

Screening for malnutrition is recommended in hospitalized and planned surgical patients. The aim of this study was to analyze the feasibility and routine prognostic value of using the principal recommended nutritional screening and evaluation tools for cancer patients undergoing major surgery.

Methods

This study is a prospective, 3‐month, multicenter observational trial recording weight loss, body mass index, albumin, transthyretin, and PG‐SGA. The morbidity rate was assessed on the basis of major complications (MC), whether of an infectious (MIC) or noninfectious (MNIC) nature.

Results

Two hundred seventy‐five patients were recruited at nine centers. The following percentages were recorded with respect to morbidity: 28.4% MC, 12.7% MIC, and 22.2% MNIC. Univariate analysis revealed a statistical association only between weight loss greater than 10% and MIC and hospital stay. A weight loss of 15% is required to demonstrate an association with either MC, MIC, or MNIC. Body mass index (BMI) was associated only with MNIC, PG‐SGA with MC, and albumin <30 g/l was strongly associated with all types of morbidity (MC, MIC, MNIC). Multivariate analysis indicated that only albumin <30 g/l and an operating time of more than 4 h are significantly associated with morbidity.

Conclusions

In this study, the best nutritional factor for detecting the risk of MC is albumin levels below 30 g/l. A weight loss greater than 15% is required to obtain a statistically significant correlation with the existence of MC.
Overcoming Distance: Video‐Conferencing as a Clinical and Educational Tool Among Surgeons
Authors: Augestad Knut Magne , Lindsetmo Rolv Ole
Published: April 2009

Background

Since the 1960s, there has been substantial development in the uses of video‐conferencing (VC) among medical personnel, including surgeons who have adopted the technology.

Methods

A report on our own experience with VC was combined with a comprehensive PubMed search with the key words telepresence, video‐conferencing, video‐teleconferencing, telementoring and surgery, trauma, follow‐up, education, and multidisciplinary teams. A search through two peer‐reviewed telemedicine journals—Journal of Telemedicine and Telecare and Telemedicine and e‐Health Journal—and references of all included papers and identified additional reports was conducted.

Results

A total of 517 articles were identified with 51 relevant manuscripts, which included the key phrases. VC is widely used among surgeons for telementoring surgical procedures and in trauma and emergency medicine. Furthermore, VC is widely used by multidisciplinary teams and for the follow‐up of patients after surgery.

Conclusions

VC is a common clinical tool for surgeons and provides a great opportunity to alter surgical practice and to offer patients the best expertise in surgical treatment despite long distances, especially in rural areas.
Youth Action Research for Prevention: A Multi‐level Intervention Designed to Increase Efficacy and Empowerment Among Urban Youth
Authors: Berg Marlene , Coman Emil , Schensul Jean J.
Published: April 2009

Youth Action Research for Prevention (YARP), a federally funded research and demonstration intervention, utilizes youth empowerment as the cornerstone of a multi‐level intervention designed to reduce and/or delay onset of drug and sex risk, while increasing individual and collective efficacy and educational expectations. The intervention, located in Hartford Connecticut, served 114 African‐Caribbean and Latino high school youth in a community education setting and a matched comparison group of 202 youth from 2001 to 2004. The strategy used in YARP begins with individuals, forges group identity and cohesion, trains youth as a group to use research to understand their community better (formative community ethnography), and then engages them in using the research for social action at multiple levels in community settings (policy, school‐based, parental etc.) Engagement in community activism has, in turn, an effect on individual and collective efficacy and individual behavioral change. This approach is unique insofar as it differs from multilevel interventions that create approaches to attack multiple levels simultaneously. We describe the YARP intervention and employ qualitative and quantitative data from the quasi‐experimental evaluation study design to assess the way in which the YARP approach empowered individual youth and groups of youth (youth networks) to engage in social action in their schools, communities and at the policy level, which in turn affected their attitudes and behaviors.
Radiographic results of combined Salter innominate and femoral osteotomy in Legg–Calvé–Perthes disease in older children
Authors: Javid Mahzad , Wedge John H.
Published: April 2009

Purpose

Treatment of Legg–Calvé-Perthes disease in older children with greater involvement of the femoral head remains uncertain. Innominate, femoral or combined innominate and femoral osteotomies are generally performed to better contain and provide more coverage of the femoral head by the acetabulum with the objective of achieving a more spherical head and a congruent joint. The purpose of the study was to evaluate the radiographic outcomes of simultaneous femoral and pelvic osteotomies.

Methods

We reviewed the radiographic changes of 20 patients with Legg–Calvé–Perthes disease with a disease onset of over eight years of age who had undergone combined femoral and Salter innominate osteotomies. The hips in these 17 males and 3 females comprised 11 lateral pillar (LP) group B, 7 B/C, and 2 C. The patients were evaluated with a mean follow-up of five years and five months using the Stulberg radiographic assessment.

Results

Among those 20 hips, six became Stulberg II (SII), nine SIII, and five SIV. From the 11 LPB hips, five became SII, four SIII, and two SIV. The seven LPB/C turned out to be SII in one case, SIII in four, and SIV in two hips. One of the two LPC hips became SIII and the other one SIV. The three female patients had one LPB, one LPB/C, and one LPC hip, and surgery resulted in SIII hips in all three cases. Eight of these 20 cases were older than 11 years of age at the time of surgery, and all had fair or poor hips.

Conclusions

Simultaneous femoral and Salter innominate osteotomies in older children with a higher LP grouping can marginally improve the radiographic outcome in comparison with the natural history in LPB/C and LPC cases by converting a number of poor results to fair results.
Detecting Liquidity Traders
Authors: Kalay Avner , Wohl Avi
Published: April 2009

We develop a measure (based on the relative slopes of the demand and supply schedules) quantifying the asymmetric presence of liquidity traders in the market: a steeper slope of the demand (supply) schedule indicates a concentration of liquidity traders on the demand (supply) side. Using the opening session of the Tel Aviv Stock Exchange, we demonstrate the predictive power of our measure. Consistent with theory, we find that the concentration of liquidity traders on the demand (supply) side is negatively (positively) correlated with future returns. We find that liquidity traders are likely to arrive at the market together (commonality).
Stock and Bond Market Liquidity: A Long-Run Empirical Analysis
Authors: Goyenko Ruslan Y. , Ukhov Andrey D.
Published: April 2009

This paper establishes liquidity linkage between stock and Treasury bond markets. There is a lead-lag relationship between illiquidity of the two markets and bidirectional Granger causality. The effect of stock illiquidity on bond illiquidity is consistent with flight-to-quality or flight-to-liquidity episodes. Monetary policy impacts illiquidity. The evidence indicates that bond illiquidity acts as a channel through which monetary policy shocks are transferred into the stock market. These effects are observed across illiquidity of bonds of different maturities and are especially pronounced for illiquidity of short-term maturities. The paper provides evidence of illiquidity integration between stock and bond markets.
FRAMEWORKS FOR INTERPRETING FRENCH CARIBBEAN WOMEN'S THEATRE: INA CÉSAIRE'SISLAND MEMORIESAT THE THÉÂTRE DU CAMPAGNOL
Authors: Sahakian Emily
Published: April 2009

The plays and performances of French Caribbean women, which have mostly been examined in the French language and in the field of French literary studies, require a new theorization of postcolonial theatre. Highly influenced by what I call French universalism, French Caribbean women's theatre moves continuously between evoking Caribbean and gender difference and mobilizing the concept of the human universal. Their work enacts a restorative postcolonial women's agenda that is specific to the cultural context of the French overseas departments of Martinique and Guadeloupe.
RESURRECTING SIZWE BANZI IS DEAD (1972–2008): JOHN KANI, WINSTON NTSHONA, ATHOL FUGARD, AND POSTAPARTHEID SOUTH AFRICA
Authors: Cima Gibson Alessandro
Published: April 2009

On 30 June 2006 at the annual National Arts Festival in Grahamstown, South Africa, two giants of South African protest theatre, John Kani and Winston Ntshona, performed as the original cast of the landmark struggle drama Sizwe Banzi Is Dead (1972). The revival marked the first production of the play in over twenty-five years. After its brief stint at the National Arts Festival (30 June–5 July 2006), the play transferred to the Baxter Theatre in Cape Town (11 July–5 August) and then entertained a monthlong run at the State Theatre in Pretoria (17 August–17 September). After its turn at the State, the production stopped shortly at the Hilton College Theatre in KwaZulu Natal (19–23 September) before settling into an extended engagement at Johannesburg's Market Theatre (28 September to 22 October). In March 2007, the original cast revival of Sizwe traveled to the British National Theatre before finally ending its tour at the Brooklyn Academy of Music in April 2008.
Studies on possible alternative schemes based on two-laser driver for inertial fusion energy applications
Authors: Strangio C. , Caruso A. , Aglione M.
Published: April 2009

Unconventional, promising approaches to inertial fusion energy (IFE) proposed and studied in the framework of IFE keep-in-touch activity at Frascati EURATOM-ENEA Association will be reconsidered for the present more advanced technological context associated to a planned large installations scenario. Then the possibility to generate laser-produced fast heavy-ion sources (e.g., Bi ions, tens GeV) will be explored taking as reference results obtained in the FIGEX experiment scaled toward thermonuclear regimes. A possible dimensioning of such sources will be also given as well as the associated laser requirements.
Relativistic electron beam source with uniform high-density emitters by pulsed power generators
Authors: Li Limin , Liu Lie , Xu Qifu , Chen Guoxin , Chang Lei , Wan Hong , Wen Jianchun
Published: April 2009

The remaining challenges, confronting high-power microwave sources and pulsed power technology, stimulate the development of robust relativistic electron beam sources. This paper presents a carbon-fiber-aluminum cathode with high-density uniform emitters, which was tested in a single pulsed power generator (~450 kV, ~350 ns, ~50 Ω) and a repetitive one (350 kV, <10 ns, 150 Ω, and 100 Hz). The distribution and development of the cathode plasma was observed by time-and-space resolved diagnostics, and the uniformity of electron beam density was checked by taking x-ray images. A quasi-stationary behavior of the cathode plasma expansion was observed. It was found that the uniformity of the extracted electron beam is satisfactory in spite of individual plasma jets on the cathode surface. Under repetitively pulsed operation, this cathode exhibited a good shot-to-shot reproducibility even in poor vacuum. This new class of plasma cathodes offers a promising prospect of developing relativistic electron beam sources.
Dynamic screening and charge state of fast ions in plasma and solids
Authors: Nardi E. , Maron Y. , Hoffmann D.H.H.
Published: April 2009

This paper addresses the effect of target plasma electrons on the charge state of energetic ions, penetrating a target composed of bound as well as plasma electrons. Dynamic screening of the projectile Coulomb potential by the plasma electrons brings about a depression in the ionization energy of the ionic projectiles, as has been verified experimentally. This in turn makes the ionization cross-sections larger, while making the recombination cross-section smaller, thereby causing an increase in the ion charge state compared to the case of a gas target. The effect of the plasma environment, where the valence electrons are treated as plasma, is illustrated here for a 2 MeV carbon beam penetrating amorphous carbon targets of varying densities.
Entwicklungsbedingte Koordinationsstörung
Authors: Kastner Julia , Petermann Franz
Published: April 2009

Zusammenfassung. Bewegung spielt im Kindesalter eine herausragende Rolle, damit sich Kinder altersentsprechend entwickeln können. Die Kernsymptome bestehen in Defiziten in den Bereichen der Grob- und Feinmotorik, die das Ausführen alltäglicher Handlungen erschweren und sich zudem negativ auf die Schulleistungen der Betroffenen auswirken. Die Ursache der Störung konnte bisher nicht geklärt werden. Viele Studien deuten darauf hin, dass sich die Defizite nicht auf das Kindesalter beschränken, sondern dass viele Personen auch im Erwachsenenalter noch Symptome aufweisen. In der Regel treten die motorischen Beeinträchtigungen nicht isoliert auf, sondern werden von einer Vielzahl psychosozialer Probleme begleitet. Dazu zählen vor allem ein verringertes Selbstwertgefühl sowie die soziale Isolation. Der diagnostische Prozess sollte umfassend sein um zu gewährleisten, dass betroffene Kinder angemessen behandelt werden, um ihren Entwicklungsverlauf positiv zu beeinflussen.
Selbstmedikation und Sozialphobie
Authors: Stevens Stephan , Gerlach Alexander L.
Published: April 2009

Zusammenfassung. Hintergrund: Der Fragebogen „Trinken wegen sozialer Angst” (TWSA; Wagner, Stangier, Heidenreich & Schneider, 2004 ) erfasst das Motiv, Alkohol zur Reduktion sozialer Angst einzusetzen. Das Instrument wurde bisher nur bei Alkoholabhängigen untersucht. Hier sollen Reliabilität und konvergente Validität in einer sozialphobischen sowie einer gesunden Stichprobe geprüft werden. Methode: 120 Patienten mit Sozialphobie und 120 Gesunde bearbeiteten den TWSA. Zur Überprüfung der Konstruktvalidität wurden Maße zur Psychopathologie, die Alkoholwirkungserwartungen und die Höhe des Alkoholkonsums erfasst. Ergebnisse: Der TWSA hat eine gute Reliabilität (Cronbachs α = .96). Es zeigen sich bedeutsame Korrelationen mit Maßen zur sozialen Angst. Ebenfalls ergeben sich Zusammenhänge zu Alkoholwirksamkeitserwartungen sowie zur konsumierten Alkoholmenge. Teilnehmer mit Sozialphobie erzielten höhere Werte als Gesunde. Diskussion: Die Ergebnisse belegen, dass der TWSA auch bei Patienten mit Sozialphobie und gesunden Personen reliabel und valide eingesetzt werden kann. Die für Patienten mit Sozialphobie erhöhten Werte unterstreichen die Notwendigkeit der Diagnostik komorbider substanzbezogener Störungen.
Universelle Prävention kindlicher Verhaltensstörungen mithilfe einer elternzentrierten Maßnahme
Authors: Heinrichs Nina , Hahlweg Kurt , Naumann Sebastian , Kuschel Annett , Bertram Heike , Ständer Dagmar
Published: April 2009

Zusammenfassung. Theoretischer Hintergrund: Psychische Probleme bei Kindern sind weit verbreitet und durch psychotherapeutische Interventionen alleine nicht zu reduzieren. Prävention ist daher dringend notwendig, aber es ist unklar, wie wirksam solche Maßnahmen sein können, vor allem langfristig. Fragestellung: Kann eine elternzentrierte universelle Präventionsmaßnahme, die kurzfristig effektiv ist, auch langfristig bedeutsame Effekte erzielen? Methode: Eltern wurden gemäß ihrer Kitazugehörigkeit zufällig der Durchführung eines Präventionsprogramms (Elterntraining Triple P, EG) oder einer Kontrollgruppe (KG) zugewiesen. Die langfristige Wirksamkeit wurde nach drei Jahren mithilfe von Fragebogen sowohl aus Sicht der Mütter als auch der Väter überprüft. Ergebnisse: Beide Eltern berichten auch drei Jahre später noch über signifikante Reduktionen im dysfunktionalen Erziehungsverhalten. Darüber hinaus zeigt sich erstmalig auch ein Effekt im positiven Erziehungsverhalten aus Sicht der Mütter. Die zuvor berichteten positiven Auswirkungen auf das kindliche Problemverhalten finden sich nicht mehr. Allein erziehende Mütter der EG erzielen hingegen keine signifikant besseren Effekte als alleinerziehende Mütter der KG, was sich vor allem durch die unerwartet hohen positiven Effekte der allein erziehenden Mütter in der KG ergibt. Schlussfolgerungen: Die Ergebnisse unterstützen die langfristige Wirksamkeit des Triple P-Gruppenprogramms als universelle Maßnahme in der Änderung des Erziehungsverhaltens für Zwei-Eltern-Familien, aber nicht eindeutig für allein erziehende Mütter. Eine Auswirkung auf kindliches Problemverhalten ist nach drei Jahren nicht mehr eindeutig nachzuweisen.