bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical properties of 422 stainless steel repaired via wire feed laser welding
Authors: Yang T. C. , Lin J. C. , Chen C.
Published: April 2004

Laser welding with filler wire additions could be used in restoration of components that are of high cost or sometimes difficult to procure, such as steam turbine blades in fossil fuel power plants. In the present work, machined V groove specimens were employed to simulate laser repair of Carpenter 636 stainless steel (SS), which has a similar composition to a blade material, type 422 SS. Before repair welding, a heat treatment procedure including solution and temper treatments of the specimens was carried out according to the mechanical and microstructural analyses of a used blade after 20 years service at about 540° C. Tensile, impact, and fatigue crack growth tests of weld repairs using 410 SS filler wire were conducted. The weld repairs exhibited an impact toughness similar to that of the base metal and a lower fatigue crack growth rate than the base metal. However, the lower hardness associated with 410 SS filler metal led to tensile fracture in the weld metal of repaired specimens. Accordingly, the use of 410 SS filler metal for repair welding type 422 SS components should be limited to regions under low stress.
Simulation of dissimilar weld joints of steel P91
Authors: Sopoušek J. , Foret R. , Jan V.
Published: April 2004

Results of computer simulations of long term service exposure for weldments of the CSN 15 128/P91 and SK3STC/P91 steels are presented and compared with corresponding results of phase and composition experiments. The welded material P91 (EU designation: X10CrMoVNb 9–1) represents progressive chromium steel alloyed with molybdenum, vanadium, carbon, and nitrogen. The CSN 15 128 (13CrMoV 2–5) material is low alloy Cr–Mo–V steel. The SK3STC alloy (12CrMo 10–10) represents the consumable electrode material. The stability of the weldment microstructure is investigated at elevated temperatures (500–700° C). The simulation method is based on the Calphad approach complemented with the theory of multicomponent bulk diffusion, local conditions of phase equilibrium, and the assumption that diffusion is the process that controls the rate of phase transformation. Significant phase profiles, concentration profiles, and phase transformation processes in the diffusion affected zone are simulated, investigated, and compared with experimental results. The potentially deleterious carbon depleted region inside each weld joint is discussed. The method described can be used to predict microstructure instability in weld joints.
Laser based welding of cellular aluminium
Authors: Haferkamp H. , Bunte J. , Herzog D. , Ostendorf A.
Published: April 2004

Lightweight materials are becoming increasingly important in construction because of the potential for savings in resources and energy. The use of cellular materials is a promising approach to reduce the weight of components further. In the last decade, significant progress has been made in the production of aluminium foams. However, the lack of techniques for the further processing of these new materials has so far prevented widespread industrial use. The present paper reports the results from laser welding of aluminium foam, and shows that the process is a productive joining method for this innovative material. Because of the spatially limited energy input of the laser, a collapse of the foam structure can be effectively avoided. Based on the investigations carried out on the welding of aluminium foams, the process has been transferred to the joining of cellular aluminium with solid materials. The characteristics of the seams were evaluated using micro-computer tomography and reflective light microscopy as well as static and dynamic strength tests.
Sequence requirements for function of theDrosophilachorion gene locus ACE3 replicator and ori-β origin elements
Authors: Zhang Hongjun , Tower John
Published: April 2004

The developmentally regulated amplification of the Drosophilathird chromosome chorion gene locus requires multiple chromosomal elements. Amplification control element third chromosome (ACE3) appears to function as a replicator, in that it is required in cis for the activity of nearby DNA replication origin(s). Ori-β is the major origin in the locus, and is a sequence-specific element that is sufficient for high-level amplification in combination with ACE3. Sequence requirements for amplification were examined using a transgenic construct that was buffered from chromosomal position effects by flanking insulator elements. The parent construct supported 18- to 20-fold amplification, and contained the 320 bp ACE3, the ∼1.2 kb S18 chorion gene and the 840 bp ori-β. Deletion mapping of ACE3 revealed that an evolutionarily conserved 142 bp core sequence functions in amplification in this context. Several deletions had quantitative effects,suggesting that multiple, partially redundant elements comprise ACE3. S. cerevisiae ARS1 origin sequences could not substitute for ori-β,thereby confirming the sequence specificity of ori-β. Deletion mapping of ori-β identified two required components: a 140 bp 5′ element and a 226 bp A/T-rich 3′ element called the β-region that has significant homology to ACE3. Antibody to the origin recognition complex subunit 2 (ORC2)recognizes large foci that localize to the endogenous chorion gene loci and to active transgenic constructs at the beginning of amplification. Mutations in Orc2 itself, or the amplification trans regulator satineliminated the ORC2 foci. By contrast, with a null mutation of chiffon (dbf4-like) that eliminates amplification, diffuse ORC2 staining was still present, but failed to localize into foci. The data suggest a novel function for the Dbf4-like chiffon protein in ORC localization. Chromosomal position effects that eliminated amplification of transgenic constructs also eliminated foci formation. However, use of the buffered vector allowed amplification of transgenic constructs to occur in the absence of detectable foci formation. Taken together, the data suggest a model in which ACE3 and ori-β nucleate the formation of a ORC2-containing chromatin structure that spreads along the chromosome in a mechanism dependent upon chiffon.
Medical Chemists and the Origins of Clinical Chemistry in Britain (circa 1750–1850)
Authors: Coley Noel G
Published: April 2004

In this history, I review developments leading toward the establishment of clinical chemistry in Britain. Chemical research by certain physicians occurred in the context of medical traditions founded on vitalism, distillation analysis, and limited chemical knowledge. Urine chemistry figured prominently in this period together with the analysis of kidney and bladder stones. Bright’s team studying albuminuria was the first clinical research school in Britain, whereas Prout’s survey of physiological chemistry, based on meticulous attention to analysis, was the best summary of human metabolism before Liebig’s Animal Chemistry. Liebig’s ideas influenced all physicians who were interested in chemistry. Henry Bence Jones based his medical practice on Liebig’s theories. His research relating urinary phosphates to diet and exercise revealed the so-called Bence Jones proteins and investigated the distribution and persistence of drugs in the body. J.L.W. Thudichum used analytical skills learned from Liebig in his brain chemistry work. George Owen Rees investigated urine analysis and the relationship between urine and blood, using Liebig’s practical methods while condemning an uncritical acceptance of his theories. These and similar studies showed that chemistry could improve clinical medicine, and because it could also reveal the onset of disease even before clinical symptoms developed, it offered valuable support to preventive medicine. However, so many physicians resisted the introduction of chemistry that progress toward the establishment of clinical chemistry in nineteenth-century Britain was slow.
Deconvolution of alpha liquid scintillation spectra for quantitative analysis of actinide elements in water samples
Authors: Aupiais Jean
Published: April 2004

The reliability and accuracy of actinide measurement in environmental samples strongly depend on the α-spectrum deconvolution process used to identify all radionuclides present in the sample, and the necessity to take into account internal conversion is demonstrated. In this process, all actinides can be resolved as the sum of three peaks: the main alpha transition and two sum peaks for which the additional α ray is merged with the internal conversion on L-shell peak and with all other conversions on M-shell, N-shell, etc.

The intensity of the internal conversions for thorium, uranium, plutonium and americium have been calculated and normalised to the intensity of the main alpha transition. These data can be used to determine the activity of any above-mentioned actinide by alpha liquid scintillation with alpha/beta discrimination. The quantitative analysis and the isotopic ratio determination of several certified solutions of actinides demonstrate the validity of this approach.
An EXAFS and TRLFS study of the sorption of trivalent actinides onto smectite and kaolinite
Authors: Stumpf Thorsten , Hennig C. , Bauer A. , Denecke Melissa A. , Fanghänel Th.
Published: April 2004

The structure parameters of the Am3+ aquo ion and of Am(III) sorbed onto smectite and kaolinite at varying pH are analyzed using EXAFS. An Am-O distance of 2.47-2.49Å is found and a coordination number of 8-9 oxygen atoms is observed for the Am3+ and its hydration sphere. Combined TRLFS (Cm(III)) and EXAFS (Am(III)) results show that An(III) sorbs onto smectite at pH 4, forming an outer-sphere complex and retains its complete primary hydration sphere. With increasing pH, inner-sphere sorption onto smectite and kaolinite occurs. The overall number of oxygen atoms coordinating the actinide ion remains about the same at pH 6, with four water molecules being replaced by oxygen atoms from the mineral surface during inner-sphere complex formation. The coordination number of sorbed Am(III) at pH 8 exhibits an apparent decrease, which may be affected by the formation of ternary OH-/Am/clay mineral surface species.
Molecular characterization of inv dup del(8p): Analysis of five cases
Authors: Shimokawa Osamu , Kurosawa Kenji , Ida Tomoko , Harada Naoki , Kondoh Tatsuro , Miyake Noriko , Yoshiura Kohichiro , Kishino Tatsuya , Ohta Tohru , Niikawa Norio , Matsumoto Naomichi
Published: April 2004

We analyzed five patients with inverted duplication deletion of 8p [inv dup del(8p)] using fluorescence in situ hybridization (FISH) and short tandem repeat polymorphism (STRP) analysis. In all patients, inv dup del(8p) consisted of a deleted distal segment, an intact in‐between segment, and a duplicated proximal segment. In all of them, the proximal breakpoint of the deletion and one of the breakpoints of the duplication were identical, each located at one of the two olfactory receptor gene clusters at 8p23. FISH analysis showed all their mothers to be heterozygous carriers of an 8p23 inversion [inv(8)(p23)]. STRP analysis indicated that the deletions occurred in maternally derived chromosomes. The duplicated segments had two copies of maternal, either heterozygous or homozygous alleles. These findings support and reinforce those in 16 patients with inv dup del(8p) and their parents by Floridia et al. [1996: Am J Hum Genet 58:785–796] and subsequent additional studies of 10 of them by Giglio et al. [2001: Am J Hum Genet 68:874–883]. Based on these findings, we propose a model for the inv dup del(8p) formation. The inverted segment and its normal counterpart in inv(8)(p23) heterozygous carrier mothers form a loop at the pachytene period of meiosis I. Inv dup del(8p) with heterozygous duplication is formed through at least one meiotic recombination within the loop. Inv dup del(8p) with the homozygous duplication arises through two meiotic recombinations on the inv(8)(p23) chromosome (one within the loop and the other between the loop and centromere). Subsequent rescue by eliminating a part of the duplicated segment and a centromere enables formation of viable inv dup del(8p). The frequency of the inv(8)(p23) allele is 39% in a normal Japanese population, comparable to 26% in Europeans Giglio et al. [2001: Am J Hum Genet 68:874–883]. The proposed mechanism of formation of inv dup del(8p) requires two independent events (a recombination within the loop and subsequent rescue), which may explain its rarity. © 2004 Wiley‐Liss, Inc.
COMT: A common susceptibility gene in bipolar disorder and schizophrenia
Authors: Shifman Sagiv , Bronstein Michal , Sternfeld Meira , Pisanté Anne , Weizman Avraham , Reznik Ilya , Spivak Baruch , Grisaru Nimrod , Karp Leon , Schiffer Richard , Kotler Moshe , Strous Rael D. , Swartz‐Vanetik Marnina , Knobler Haim Y. , Shinar Eilat , Yakir Benjamin , Zak Naomi B. , Darvasi Ariel
Published: April 2004

A variety of psychiatric illnesses, including schizophrenia and bipolar disorder, have been reported in patients with microdeletion on chromosome 22q11—a region which includes the catechol‐O‐methyltransferase (COMT) gene. The variety of psychiatric manifestations in patients with the 22q11 microdeletion and the role of COMT in the degradation of catecholamine neurotransmitters may thus suggest a general involvement of the COMT gene in psychiatric diseases. We have previously reported on a significant association between a COMT haplotype and schizophrenia. In this study, we attempt to test for association between bipolar disorder and the polymorphisms implicated in schizophrenia. The association between COMT and bipolar disorder was tested by examining the allele and haplotype found to be associated with schizophrenia. A significant association between bipolar disorder and COMT polymorphisms was found. The estimated relative risk is greater in women, a result consistent with our previous findings in schizophrenia. We suggest that polymorphisms in the COMT gene may influence susceptibility to both diseases—and probably also a wider range of behavioral traits. © 2004 Wiley‐Liss, Inc.
Catalytic activities of amino acid modified, starch‐grafted acrylamide for the decomposition of hydrogen peroxide
Authors: El‐Hamshary Hany , Al‐Sigeny Samia
Published: April 2004

Acrylamide was grafted onto corn starch with ceric(IV) ions as an initiator. Starch‐graft‐polyacrylamide was modified with amino acids through a reaction with the sodium salts of glycine, β‐alanine, and phenylalanine. The catalytic activities of the iron(III) complexes of the amino acid modified grafted materials were investigated for the decomposition of hydrogen peroxide (H2O2). These new polymeric supports were found to be active in the catalytic decomposition of H2O2. The extent of decomposition varied with the composition of the support. The iron(III) complex of the glycine‐modified material was the most active of the amino acid supported catalysts. Factors that affected the rate of reaction, such as the concentration of H2O2, the amount of the catalyst, the pH, and the temperature, were investigated. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 630–636, 2004
Syntheses and Phase‐Transfer Properties of Dendritic Nanocarriers That Contain Perfluorinated Shell Structures
Authors: Garcia‐Bernabé Abel , Krämer Michael , Olàh Bèla , Haag Rainer
Published: April 2004

Perfect dendrimers that contain perfluorinated shells have recently attracted attention because they have been shown to encapsulate polar molecules in supercritical CO2 and catalytically active metal nanoparticles in perfluorinated solvents. Moreover, they can then be easily separated after reaction from the biphasic organic/fluorous system. In this paper several dendritic architectures that contain perfluorinated shells were derived by covalent modification of glycerol dendrimers ([G0.5]–[G3.5]), hyperbranched polyglycerol, and polyethyleneimine. These core‐shell architectures show interesting physicochemical properties. For example, they are soluble in fluorinated solvents, they are able to transport different guest molecules, and they display thermomorphic behavior. The transport capacity of these molecular nanocarriers increases significantly when amino groups are present in the core. Certain functionalized polyethyleneimines that contain perfluorinated shells show high transport capacities (up to 3 dye molecules per nanocarrier) in perfluorinated solvents. Moreover, these perfluoro‐functionalized dendritic polyethyleneimines can act as templates that stabilize nanoparticles; for example, encapsulation and subsequent chemical reduction of AgI ions. Silver nanoparticles with a narrow size distribution (3.9±1 nm) have been prepared and characterized by transmission electron microscopy. Furthermore, it has been demonstrated that the encapsulated guest molecules remain accessible to small molecules after transport into the fluorous phase. Therefore, dendritic nanocarriers that contain perfluorinated shells are currently being investigated as polar environments in nonpolar reaction media such as fluorous phases and supercritical CO2, in particular, for application in homogenous catalysis.
The Role of Hydrogen Bonding in the Crystal Structures of Zinc Phosphate Hydrates
Authors: Herschke Laurent , Enkelmann Volker , Lieberwirth Ingo , Wegner Gerhard
Published: April 2004

The compounds α‐ and β‐hopeite have been synthesised by hydrothermal crystallisation from aqueous solution at 90 °C and 20 °C, respectively. The crystal structures of these polymorphic forms of zinc phosphate tetrahydrate (ZPT), Zn3(PO4)2⋅4 H2O, have been resolved. Single‐crystal analysis proves that the main difference between the α and β forms of ZPT is caused by the difference in orientation of one of the water molecules in the ZnO6 octahedral network, indicating two different hydrogen‐bonding patterns. A previously unknown hopeite, Zn3(HPO4)3⋅3 H2O (ZHPT), has been isolated and analysed. This helps to achieve a better understanding of the mechanism of formation of zinc phosphate compounds. Unambiguous identification of each phase is established by analysis of their unique thermal behaviour and thermodynamic interrelationship.
Stephanie Bryant and Feiyi Wang, Aspects of adaptive reconfiguration in a scalable intrusion tolerant system, Complexity (2004) 9(2)74–83
Authors: Bryant Stephanie , Wang Feiyi
Published: April 2004

The original article to which this Erratum refers was published in Complexity (2004) 9(2)74–83

No abstract.
Nonlinear Heat Transport in Anisotropic Divertor Targets Irradiated by Laser Pulses
Authors: Bachmann P. , Hildebrandt D. , Sünder D.
Published: April 2004

In order to derive plasma energy outflux from thermographic measurements an inverse heat conduction problem must be solved. A solution method for the time‐dependent three‐dimensional heat conduction equation is presented which improves an analytical Green's function solution by a numerical iteration method to include nonlinear effects. The measured temperature excursion of a graphite surface irradiated by laser heat flux pulses can be well described by the model calculations. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Incorporating Line Radiation Effects into Edge Plasma Codes
Authors: Scott Howard A. , Adams Mark L.
Published: April 2004

Strong hydrogen line radiation can significantly affect the ionization and energy balance in high‐density, lowtemperature edge plasmas. A fully self‐consistent one‐dimensional simulation code integrating line radiation with edge plasma transport has recently been demonstrated. This code allows us to evaluate the use of approximate treatments of radiation effects that could potentially be incorporated into existing two‐dimensional edge plasma codes. For a given approximation, we tabulate effective ionization, recombination and energy loss rates for hydrogen plasmas in a one‐dimensional geometry as a function of electron density, temperature and position. The position is a simple parameterization corresponding to optical depth, with the correspondence dependent on plasma properties, including magnetic field. The parameterized values can differ by more than an order of magnitude from the optically thin values.

We present one‐dimensional edge plasma simulations using the parameterized tables and compare them to self‐consistent simulations to investigate the validity of this approach, the effectiveness of the parameterization and the accuracy of the approximations used. We also present results using parameterized tables in a twodimensional code and discuss the validity of applying them in this manner. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
3D Edge Modeling and Island Divertor Physics
Authors: Feng Y. , Sardei F. , Kisslinger J. , Grigull P. , McCormick K. , Reiter D.
Published: April 2004

The paper presents an overview on the state of the art of 3D fluid transport modeling in the boundaries of 3D toroidal confinement devices and on applications to island divertor physics. Typically, such edge configurations are characterized by the coexistence of closed magnetic surfaces, islands and open stochastic regions, e.g. in helical devices like W7‐AS, W7‐X, LHD and in tokamaks like TEXTOR‐DED. Two main approach branches falling within the current numeric catalogue of the 3D modeling are the finite volume andMonte Carlo methods. They differ essentially in the elementary treatment of the local transport. While in a finite volume method interpolation of the fluid fluxes through the interfaces by appropriate choice of a shape function is essential for the discretization process, the full fluid dynamics are, in a Monte Carlo approach, simulated by means of a local stochastic process, with the fluxes passing through cell boundary surfaces being a net result of the random process. In this paper, we present the numerics and strategies proposed in different models. Concerning the practical applications to a realistic 3D experiment, W7‐AS provides not only a practical fully 3D island divertor configuration but also sufficient experimental data for code validation. We present the main simulation results from the 3D edge Monte Carlo code EMC3/EIRENE and discuss the island divertor physics with respect to tokamak divertors. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Drift‐ordered fluid equations for modelling collisional edge plasma
Authors: Simakov A. N. , Catto P. J.
Published: April 2004

The fluid description of collisional magnetized plasma by Braginskii is based on an ordering assuming the species flow velocities to be on the order of the ion thermal speed. This large flow assumption is normally not valid for plasma fusion devices in general and tokamak edge plasmas in particular. To remove this shortcoming Mikhailovskii and Tsypin developed a plasma fluid description assuming the flow velocities to be on the order of the diamagnetic drift velocities, which are smaller than the ion thermal speed. However, when deriving their equations Mikhailovskii and Tsypin missed important terms in their expressions for the species collisional viscous stress tensors. Starting from corrected Mikhailovskii‐Tsypin fluid equations, we derive a system of non‐linear reduced equations describing field‐aligned fluctuations in low‐beta collisional magnetized edge plasma; namely, equations for plasma density, electron and ion energies (or, equivalently, temperatures), parallel ion flow velocity, parallel current, vorticity (or, equivalently, electrostatic potential), perturbed parallel electromagnetic potential, and perturbed magnetic field. Our equations locally conserve particle number and total energy, and insure that perturbed magnetic field and total plasma current are divergence‐free. In addition, while intended primarily for modelling plasma turbulence, they contain the neoclassical results for plasma current, parallel ion flow velocity, and parallel gradients of equilibrium electron and ion temperatures. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reconstruction of Velocity Distribution of Density Bursts by Wavelet Analysis in the Linear Divertor Simulator NAGDIS‐II
Authors: Ohno N. , Budaev V. P. , Furuta K. , Miyoshi H. , Takamura S.
Published: April 2004

We have investigated the velocity distribution of the intermittent bursty fluctuations in the ion saturation currents observed in the linear divertor plasma simulator, NAGDIS‐II. The intermittent bursty signals were analyzed by the wavelet transform with complex Morlet mother wavelet. Analyzing a lot of bursts in the ion saturation currents based on the wavelet cross‐correlation gives the velocity distribution function. It is positively skewed at the peripheral region of the plasma column, which means the intermittent bursts mainly propagate toward the wall. The averaged velocity depends on the neutral pressure associated with the transition between the attached and detached plasmas. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multi‐fluid code simulation of DIII‐D filterscope data including reflection of light from plasma‐facing surfaces
Authors: Hollmann E. M. , Pigarov A. Yu.
Published: April 2004

A comparison is made between solutions of the UEDGE multi‐fluid edge code and the full array of 24 poloidal and tangential Dα and CIII filterscope views available in DIII‐D for a lower single null L‐mode discharge. Wall reflections are included using measured graphite tile reflection data together with a 3D ray tracing code. It is found that divertor view chords are relatively unperturbed by reflections, while main chamber views can be dominated by reflected light. Main chamber view chords are shown to be important in distinguishing between different radial transport models: a hybrid model including both convection and diffusion is found to match measured main chamber Dα brightnesses well, while a pure diffusive model gives brightnesses which are of order 100× too small. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparative expression analysis of the MAGED genes during embryogenesis and brain development
Authors: Bertrand Mathieu , Huijbers Ivo , Chomez Patrick , De Backer Olivier
Published: April 2004

The MAGED gene subfamily contains three genes in mouse and four in human. The MAGED1, D2, and D3 proteins are highly conserved between mouse and human, whereas paralogues are less conserved between each other. This finding suggests that each MAGED protein exerts a distinct function. To get a better insight into their physiological roles, we have analyzed their expression patterns during embryogenesis and brain development. In the mouse, Maged3 expression is restricted to the central nervous system where it was mostly detected in postmitotic neurons. Maged2 is mainly expressed in tissues of mesodermal origin. The expression pattern of Maged1 roughly summarizes that of Maged2 and Maged3; however, contrary to that of Maged3, it includes the proliferative zones of the nervous system. We observed a discrepancy between Maged1 expression levels of RNA and protein, suggesting that its expression is regulated at a posttranscriptional level during the mouse development. Developmental Dynamics 230:325–334, 2004. © 2004 Wiley‐Liss, Inc.
Follistatin operates downstream of Wnt4 in mammalian ovary organogenesis
Authors: Yao Humphrey H.C. , Matzuk Martin M. , Jorgez Carolina J. , Menke Douglas B. , Page David C. , Swain Amanda , Capel Blanche
Published: April 2004

Wnt4‐/‐ XX gonads display features normally associated with testis differentiation, suggesting that WNT4 actively represses elements of the male pathway during ovarian development. Here, we show that follistatin (Fst), which encodes a TGFβ superfamily binding protein, is a downstream component of Wnt4 signaling. Fst inhibits formation of the XY‐specific coelomic vessel in XX gonads. In addition, germ cells in the ovarian cortex are almost completely lost in both Wnt4 and Fst null gonads before birth. Thus, we propose that WNT4 acts through FST to regulate vascular boundaries and maintain germ cell survival in the ovary. Developmental Dynamics 230:210–215, 2004. © 2004 Wiley‐Liss, Inc.
Functional knockdown of neuropilin‐1 in the developing chick nervous system by siRNA hairpins phenocopies genetic ablation in the mouse
Authors: Bron Romke , Eickholt Britta J. , Vermeren Matthieu , Fragale Ninfa , Cohen James
Published: April 2004

The chick embryo is widely used for the study of vertebrate development, but a general, reliable loss‐of‐function strategy for the analysis of gene function is currently not available. By using small inhibitory hairpin RNA (siRNA) molecules generated by the mouse U6 promoter, we have applied an RNA interference approach to achieve quantitative knockdown of the neuropilin‐1 (Nrp‐1) receptor in chick embryos. Functional knockdown was evident in the abolition of Sema3A‐induced growth cone collapse in Nrp‐1‐siRNA but not Nrp‐2‐siRNA–expressing dorsal root ganglion (DRG) neurons. Two nervous system defects in Nrp‐1 mutant mice were phenocopied in embryos treated with Nrp‐1 siRNA. First, DRG axons prematurely entered the dorsal horn and projected inappropriately. Second, targeted early migrating neural crest cells destined for the sympathetic chain arrested ectopically within ventral spinal nerve roots. Localized knockdown induced by specific siRNA constructs will allow rapid functional analysis of genes regulating chick neural development whilst circumventing embryonic lethal effects often associated with global gene knockout in the mouse. Developmental Dynamics 230:299–308, 2004. © 2004 Wiley‐Liss, Inc.
Slit and robo expression in the developing mouse lung
Authors: Greenberg James M. , Thompson Felisa Y. , Brooks Sherry K. , Shannon John M. , Akeson Ann L.
Published: April 2004

Mammalian lung development is mediated through complex interactions between foregut endoderm and surrounding mesenchyme. As airway branching progresses, the mesenchyme undergoes dramatic remodeling and differentiation. Little is understood about the mechanisms that direct mesenchymal organization during lung development. A screen for candidate genes mediating this process identified Slit, a ligand for the Roundabout (Robo) receptor previously associated with guidance of axonal projections during central nervous system development. Here, we demonstrate by in situ hybridization that two Slit genes (Slit‐2 and Slit‐3) and two Robo genes (Robo‐1 and Robo‐2) are expressed in fetal lung mesenchyme. Slit‐2 and Robo‐1 expression is present throughout mesenchyme at midgestation and is not detectable by newborn day 1. Slit‐3 and Robo‐2 expression is restricted to specific, complementary subsets of mesenchyme. Robo‐2 is expressed in mesenchymal cells immediately adjacent to large airways, whereas Slit‐3 expression predominates in mesenchyme remote from airway epithelium. The temporal and spatial distribution of Slit and Robo mRNAs indicate that these genes may direct the functional organization and differentiation of fetal lung mesenchyme. Developmental Dynamics 230:350–360, 2004. © 2004 Wiley‐Liss, Inc.
Twist is required for patterning the cranial nerves and maintaining the viability of mesodermal cells
Authors: Ota Masato S. , Loebel David A.F. , O'Rourke Meredith P. , Wong Nicole , Tsoi Bonny , Tam Patrick P.L.
Published: April 2004

Twist encodes a basic helix‐loop‐helix transcription factor that is required for normal craniofacial morphogenesis in the mouse. Loss of Twist activity in the cranial mesenchyme leads to aberrant migratory behaviour of the neural crest cells, whereas Twist‐deficient neural crest cells are located in an inappropriate location in the first branchial arch and display defective osteogenic and odontogenic differentiation (Soo et al. [2002] Dev. Biol. 247:251–270). Results of the present study further show that loss of Twist impacts on the patterning of the cranial ganglia and nerves but not that of the peripheral ganglia and nerves in the trunk region of the body axis. Analyses of the expression of molecular markers of early differentiation of the paraxial mesoderm and the histogenetic potency of somites of Twist‐/‐ embryos reveal that Twist‐deficient somites can differentiate into muscles, cartilage, and bones, albeit less prolifically. Twist function, therefore, is not essential for mesoderm differentiation. The poor growth of the Twist‐deficient somites after transplantation to the ectopic site may be attributed to reduced proliferative capacity and extensive apoptosis of the paraxial mesoderm, suggesting that Twist is required for maintaining cell proliferation and viability in the mesodermal progenitors. Developmental Dynamics 230:216–228, 2004. © 2004 Wiley‐Liss, Inc.
Kinematics and strain partitioning in the southeast Hellenides (Greece)
Authors: Kokkalas S. , Doutsos T.
Published: April 2004

New kinematic and structural data from the tectonic windows of eastern Crete and the Dodecanese Islands combined with strain and quartz fabric analysis have enabled us to determine a detailed structural evolution of the region and to present a plate tectonic scenario for the southeast Hellenides.

During the Early Mesozoic, the southeastern part of Apulia was separated from North Africa and the adjacent microplates by WNW‐trending rift zones and NE‐trending transfer faults. Displacement along the transfer faults has locally reoriented these rift zones into an ENE–WSW direction. Finite strain and quartz fabric asymmetry data indicate that in Late Cenozoic time, NNW‐directed nappe movements caused a nearly coaxial deformation along the ENE–WSW trending rift segments and non coaxial top‐to‐the‐southeast shearing along the WNW‐trending rift segments, as well as along the pre‐existing NE‐trending transfer faults. Tectonic style along the margin varies in response to the obliquity of the principal shortening direction with respect to the margin. These variations could be due to the pre‐convergence geometry of the southern margin of Eurasia and to local strain partitioning effects.

Furthermore, a tectonic model is presented in which syncompressional uplift and vertical buoyancy of the subducted crustal slice caused the rapid exhumation of metamorphic units in the south Hellenides. Copyright © 2003 John Wiley & Sons, Ltd.
Characterization of the actions of AvTx 7 isolated from Agelaia vicina (Hymenoptera: Vespidae) wasp venom on synaptosomal glutamate uptake and release
Authors: Pizzo Andrea B. , Beleboni Renê O. , Fontana Andréia C. K. , Ribeiro Alessandra M. , Miranda Antonio , Coutinho‐Netto Joaquim , dos Santos Wagner F.
Published: April 2004

It has previously been shown that the denatured crude extract of Agelaia vicina wasp venom inhibits glutamate and GABA uptake in rat cerebral cortex synaptosomes. To identify the components responsible for these effects, the neurotoxin AvTx 7 (molecular weight of 1210 Da) was isolated from A. vicina venom and its effects on glutamate neurotransmission investigated. AvTx 7 inhibits glutamate uptake in a dose‐dependent and uncompetitive manner. AvTx 7 was found to stimulate the glutamate release in the presence of calcium and sodium channel blockers, suggesting that its action is not mediated through these channels. AvTx 7 potentiates glutamate release in the presence of K+ channel blockers tetraethylammonium and 4‐aminopyridine, indicating that the toxin may act through these drugs‐sensible K+ channels. We suggest that AvTx 7 can be a valuable tool to enhance our understanding of K+ channels' involvement in the release of glutamate. © 2004 Wiley Periodicals, Inc. J Biochem Mol Toxicol 18:61–68, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20014
Analysis of an early‐onset Parkinson's disease cohort for DJ‐1 mutations
Authors: Clark Lorraine N. , Afridi Shehla , Mejia‐Santana Helen , Harris Juliette , Louis Elan D. , Cote Lucien J. , Andrews Howard , Singleton Andrew , Wavrant De‐Vrieze Fabienne , Hardy John , Mayeux Richard , Fahn Stanley , Waters Cheryl , Ford Blair , Frucht Steven , Ottman Ruth , Marder Karen
Published: April 2004

The frequency and relative contribution of DJ‐1 mutations in early‐onset Parkinson's disease (EOPD) is currently unknown. We analyzed a cohort of 89 EOPD patients (mean age at onset of PD ± SD, 41.5 ± 7.2 years), ascertained independent of family history, who participated in a study of the genetic epidemiology of PD. This study includes sequence analysis of the DJ‐1 gene in addition to assaying the 14,082‐bp deletion spanning exons 1 to 5, previously identified in a Dutch kindred, in 89 EOPD cases. A heterozygous missense mutation in exon 5 (A104T) was identified in an EOPD case of Asian ethnicity; this sequence variant was absent in 308 control chromosomes. We identified additional sequence variation in the DJ‐1 gene, including a polymorphism in the coding region in exon 5 (R98Q), three polymorphisms in the 5′ untranslated region (exon 1A/1B), and two polymorphisms in intronic regions (IVS1 and IVS5). Mutations in the DJ‐1 gene are rare in EOPD in both sporadic and familial cases. © 2004 Movement Disorder Society
Properties of Xenopus Kv1.10 channels expressed in HEK293 cells
Authors: Fry Mark , Maue Robert A. , Moody‐Corbett Frances
Published: April 2004

Voltage‐gated K+ channels play important roles in shaping the characteristics of action potentials and electrical activity. In a previous study, we isolated cDNAs encoding several distinct K+ channel isoforms, including a novel isoform (XKv1.10) expressed in Xenopus laevis spinal cord neurons and myocytes. Here, we report the biophysical characterization of XKv1.10 expressed in transiently transfected HEK293 cells. Whole cell patch clamp recordings revealed a voltage‐gated, rapidly activating and inactivating K+ current. Interestingly, the rate of inactivation of XKv1.10 channels showed apparent voltage dependence, with time constants between 77.7–213.3 ms. The predicted protein sequence of XKv1.10 does not appear to encode an N‐terminal inactivating “ball and chain” domain, and instead these channels may inactivate via a C/P‐type mechanism. Consistent with this, either increasing the external concentration of K+ or external application of tetraethylammonium caused a decrease in the rate of inactivation. Pharmacologically, XKv1.10 K+ channels were sensitive to 4‐aminopyridine and tetraethylammonium with apparent IC50 values of 68.5 μM and 17.1 mM, respectively. When simulated action potentials were used as a voltage command, XKv1.10 was similar to XKv1.4 in that it carried more repolarizing current during the action potential than XKv1.2. However, while XKv1.4 was active during the interspike interval, XKv1.10 and XKv1.2 were not. Overall, the data suggest that XKv1.10 channels make a unique contribution to the developmental maturation of electrical signaling in Xenopus laevis. © 2004 Wiley Periodicals, Inc. J Neurobiol 60: 227–235, 2004
Measuring autonomy in social security agencies: a four country comparison
Authors: Caulfield Janice L.
Published: April 2004

Many European countries manage social policy programmes through autonomous organisations. This article examines the role of these agencies in four countries, two of which (Sweden and Finland) have long histories of using agencies and two (the Netherlands and the United Kingdom) in which this style of management is more recent. The article focuses particular attention on the use of performance management in the context of devolved organisations. Copyright © 2004 John Wiley & Sons, Ltd.
The quasi‐autonomous agency in an ambiguous environment: the Centrelink case
Authors: Halligan John
Published: April 2004

Australia's Centrelink provides an unique experiment with the integration of a variety of social services through a single quasi‐autonomous organisation. This multi‐functional agency delivers services to a number of clients while subject to a range of external and internal imperatives. The case indicates the complexities in managing the interface between policy department and service delivery agency and the limitations of operating with purchaser‐provider arrangements as a basis for relationships. Copyright © 2004 John Wiley & Sons, Ltd.
Proteomic analysis of agar gel‐entrapped Pseudomonas aeruginosa
Authors: Vilain Sébastien , Cosette Pascal , Hubert Marie , Lange Catherine , Junter Guy‐Alain , Jouenne Thierry
Published: April 2004

We have compared the protein maps of agar‐entrapped Pseudomonas aeruginosa cells to those of free counterparts grown in the presence or absence of the immobilized‐cell gel support. Principal component analyses (PCAs) were used to interpret spot quantity variations observed on electropherograms obtained by two‐dimensional gel electrophoresis. PCA of the data matrix (923 rows×6 columns) in which spot density values were standardized horizontally extracted three principal components (PCs) with eigenvalues higher than 1, accounting together for 71.6% of the variability in the data. Principal component 1 (PC1) opposed free (F) and agar‐entrapped (AE) cultures, with a low contribution of agar‐released, free (ARF) cultures to PC1. Inversely, the contribution of ARF cultures to PC2 was high, opposing those of AE and F cultures. Component 3 was related to the duration of incubation. Only 10% of total proteins were upregulated in AE cells during the first 18 h of incubation, the number of underexpressed peptides balancing that of overexpressed ones. Downregulation clearly became the dominant tendency when the incubation time was extended to 48 h. These results demonstrate that AE and ARF bacteria are physiologically different from F organisms.
Nano‐Scale Tungsten Oxides for Metastable Intermolecular Composites
Authors: Perry W. Lee , Smith Bettina L. , Bulian Christopher J. , Busse James R. , Macomber Clay S. , Dye Rob C. , Son Steven F.
Published: April 2004

Tungsten oxides are of interest as an oxidant for metals in metastable intermolecular composites, a nano‐scale powder useful for such applications as electric matches and gun primers. Smaller particles typically lead to faster reactions and we have synthesized nano‐scale WO3using wet chemistry. Ammonium paratungstate was dissolved in acid. Tungstic acid was precipitated by addition to distilled water and the resulting powder was dried. Analysis by X‐ray diffraction, Raman spectroscopy and electron microscopy revealed hydrated WO3, having approximately 100 nm×7 nm platelet morphology. Thermal treatment in air at 200 °C or 400 °C removed water, forming cubic or monoclinic WO3, respectively. Tungsten forms other stable oxides and we accessed WO2by reducing WO3in dilute H2at 650 °C. Reaction performance of these WOx‐materials, mixed with nano‐Al at various stoichiometries, is reported. Open‐tray burn velocity reached 250 m/s. Pressure cell experiments found a maximum pressure of 1.45 MPa and maximum pressurization rate of 500 GPa/s. These maximum pressures and rates occurred very near a stoichiometric mixture of the Al and WO3.
Induction and function of CYR61 (CCN1) in prostatic stromal and epithelial cells: CYR61 is required for prostatic cell proliferation
Authors: Sakamoto Shinji , Yokoyama Masahiro , Aoki Michiko , Suzuki Kensuke , Kakehi Yoshiyuki , Saito Yutaka
Published: April 2004

BACKGROUND

CYR61 is an extracellular matrix‐associated protein that promotes adhesion, migration, and proliferation of endothelial cells and fibroblasts. Prostate enlargement, which frequently causes the urethral compression, is often histologically observed as stromal and epithelial hyperplasia in an enlarged gland. To determine whether or not CYR61 has relevance to the progression of benign prostatic hyperplasia (BPH), we investigated the induction of CYR61, and also examined its function in both prostatic stromal and epithelial cells.

METHODS

Recombinant CYR61 protein was used for the examination of the activity of CYR61 as to cell adhesion and proliferation. Quantitative reverse transcription‐polymerase chain reaction (RT‐PCR) was utilized to screen for inducers of the CYR61 gene in prostatic cells. Finally, the effects of an anti‐sense oligonucleotide, which could reduce the production of CYR61, on the morphology and growth of prostatic cells were also examined.

RESULTS

Recombinant CYR61 protein promotes prostatic cell adhesion and proliferation. The mRNA for CYR61, a growth factor‐inducible immediate early gene, was markedly induced by fetal bovine serum (FBS) within 1 hr, and strongly induced by transforming growth factor‐β1 (TGF‐β) for at least 19 hr following stimulation. The suppression of CYR61 production with an anti‐sense oligonucleotide causes obvious morphological changes of prostatic cells. Furthermore, we have shown that CYR61 is necessary, at least in part, for FBS‐induced prostatic cell proliferation, because dramatic inhibition of cellular growth was caused by the suppression of CYR61 production with the addition of the anti‐sense oligonucleotide before FBS stimulation.

CONCLUSIONS

In this study, we demonstrate that serum growth factors induce the CYR61 gene in both stromal and epithelial cells, and that CYR61 plays functional roles in cell adhesion, morphology, and proliferation, supporting its involvement in benign prostatic enlargement. These results strongly suggest that CYR61 is a key molecule, and therefore could be a potential therapeutic target in prostatic hyperplastic growth. © 2004 Wiley‐Liss, Inc.
Lesions predictive for prostate cancer in a screened population: First and second screening round findings
Authors: Postma Renske , Roobol Monique , Schröder Fritz H. , van der Kwast Theodorus H.
Published: April 2004

BACKGROUND

We evaluated the incidence of prostate cancer, high‐grade prostatic intraepithelial neoplasia (PIN) and lesions suspicious for prostate cancer (LSPC) in sextant biopsies in two subsequent screening rounds at a 4‐year interval and their predictive value for subsequent prostate cancer detection.

METHODS

In the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer (ERSPC), 4,117 men underwent sextant biopsy in the 1st screening round. The 2nd round was performed at a 4‐year interval and biopsies were taken in 1,840 men.

RESULTS

The incidences of prostate cancer, LSPC and PIN in the 1st, respectively 2nd round were 24.6, resp. 19.9% (P = 0.001), 2.7, resp. 2.8% and 0.8, resp. 2.5% (P < 0.0001). Prostate cancer incidence after repeat biopsy for LSPC in the 1st, respectively 2nd round was 36.7 and 17.0%, and after repeat biopsy for PIN 13.3% in both rounds, respectively. Men with a benign biopsy in the 1st round had a significantly lower prostate cancer incidence in the 2nd round compared to men who did not undergo biopsy in the 1st round (10.7 vs. 22.7%, P < 0.0001).

CONCLUSIONS

The decrease of prostate cancer detection in the 2nd round was associated with an increase in the incidence of PIN. Strikingly, LSPC diagnosed during the 1st round, but not during the 2nd round were predictive for prostate cancer, while isolated PIN was never predictive for prostate cancer. PIN shoud not be an indication for repeat biopsy in a screening population. Importantly a 1st round benign biopsy outcome proved to be a negative predictor of subsequent prostate cancer detection. © 2004 Wiley‐Liss, Inc.
Inhibitory effect of IL‐6‐induced neuroendocrine cells on prostate cancer cell proliferation
Authors: Wang Qingcai , Horiatis Dimitris , Pinski Jacek
Published: April 2004

BACKGROUND

The role of increased neuroendocrine (NE) differentiation in prostate cancer (PCA) is not well understood. Long‐term exposure of the prostate cancer cell line LNCaP to high concentrations of the cytokine interleukin‐6 (IL‐6) results in permanent transdifferentiation of these cells into a NE phenotype. In this study, we evaluated the effect of IL‐6‐induced NE cells on the growth of the PCA cell lines LNCaP, PC‐3, and DU‐145 in vitro.

RESULTS

Co‐culture of NE cells with PCA cells significantly inhibited DNA synthesis in all three PCA cell lines by 30–90% compared to controls. NE cell co‐culture resulted in an increased percentage of PCA cells arrested in the S‐phase of cell cycle and PCA cell apoptosis.

CONCLUSIONS

Our results imply that NE cells suppress the proliferation of surrounding PCA cells by release of inhibitory factors. © 2004 Wiley‐Liss, Inc.