bluuebunny/crossref_metadata_2025 huggingface dataset:
Melatonin reduces oxidative stress in erythrocytes and plasma of senescence‐accelerated mice
Authors: Nogués M. Rosa , Giralt Montserrat , Romeu Marta , Mulero Miquel , Sánchez‐Martos Vanesa , Rodríguez Esperanza , Acuña‐Castroviejo Darío , Mallol Jordi
Published: June 2006

Abstract:  It has been suggested that oxidative stress is a feature of aging. The goal of the present study was to assess the oxidant effects related to aging and the protective role of exogenous melatonin in senescence‐accelerated mice (SAMP8). Two groups of SAMP8 mice (males and females) were compared with their respective control groups of SAMR1 mice (senescence‐resistant inbred strain) to determine their oxidative status without melatonin treatment. Four other groups of the same characteristics were treated with melatonin (10 mg/kg/day) in their drinking water. The melatonin concentration in the feeding bottles was titrated according to water consumption and body weight (i.e. 0.06 mg/mL for 30 g of body weight and 5 mL/day of water consumption). The treatment began when animals were 1‐month old and continued for 9 months. When mice were 10‐month old, they were anesthetized and blood was obtained. Plasma and erythrocytes were processed to examine oxidative stress markers: reduced glutathione (GSH), oxidized glutathione (GSSG), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione S‐transferase (GST), thiobarbituric acid reactive substances (TBARS), and hemolysis. The results showed greater oxidative stress in SAMP8 than in SAMR1, largely because of a decrease in GSH levels and to an increase in GSSG and TBARS with the subsequent induction of the antioxidant enzymes GPX and GR. Melatonin, as an antioxidant molecule, improved the glutathione‐related parameters, prevented the induction of GPX in senescent groups, and promoted a decrease in SOD and TBARS in almost all the groups.
The Longitudinal Course of Depression in Adoptive and Birth Mothers of Children with Intellectual Disabilities
Authors: Glidden Laraine M. , Jobe Brian M.
Published: June 2006

Abstract  This report extends by an additional 6 years the longitudinal research of Glidden and Schoolcraft, who found that adoptive mothers of children with intellectual disabilities displayed low depression at the initial time of adoption and thereafter, whereas birth mothers reported significantly higher levels when their children were first diagnosed, but not at later times. Depression remained low during the current time of measurement, but mothers who had relatively high depression earlier still reported higher depression even after 17 years. Individual differences were especially consistent for adoptive mothers during the latest 6‐year period, perhaps reflecting the endogenous nature of their depression.
Characterization of human deoxyribonuclease I gene (DNASE1) promoters reveals the utilization of two transcription‐starting exons and the involvement of Sp1 in its transcriptional regulation
Authors: Kominato Yoshihiko , Ueki Misuzu , Iida Reiko , Kawai Yasuyuki , Nakajima Tamiko , Makita Chikako , Itoi Masako , Tajima Yutaka , Kishi Koichiro , Yasuda Toshihiro
Published: June 2006

Levels of deoxyribonuclease I (DNase I) activity in vivo have been shown to be altered by physiological and/or pathological processes. However, no information is available on the regulation of DNase I gene (DNASE1) expression in vivo or in vitro. We first mapped the transcription start sites of DNASE1 in human pancreas and in the DNase I‐producing human pancreatic cancer cell line QGP‐1, and revealed a novel site ∼ 12 kb upstream of exon 1, which was previously believed to be the single transcription‐starting exon. This initiation site marks an alternative starting exon, designated 1a. Exons 1 and 1a were used simultaneously as transcription‐starting exons in pancreas and QGP‐1 cells. Promoter assay, EMSA and chromatin immunoprecipitation analysis with QGP‐1 cells showed the promoter region of exon 1a in which the Sp1 transcription factor is specifically involved in promoter activity. This is the first to be identified as a transcription factor responsible for gene expression of vertebrate DNase I genes. Furthermore, RT‐PCR analysis indicated alternative splicing of human DNASE1 pre‐mRNA in pancreas and QGP‐1 cells. Only two transcripts among eight alternative splicing products identified can be translated to produce intact DNase I protein. These results suggest that human DNASE1 expression is regulated through the use of alternative promoter and alternative splicing.
Invertebrate and Vertebrate Seed Predation in the Amazonian Palm Attalea maripa1
Authors: Salm Rodolfo
Published: June 2006

Spatial‐scale‐dependent patterns of Attalea maripa seed predation and removal by the beetle Pachymerus cardo and vertebrates were examined in a palm patch and its adjacent forest in southeastern Amazon. Seed survivorship depended on the distance from the palm patch, but was unrelated to distance from individual fruiting palms.
Peptides containing Acylated C‐terminal Gem diamines: Novel Irreversible Inactivators of the Cysteine and Serine Proteinases†
Authors: Gilmore B. F. , Lynas J. F. , Harriott P. , Healy A. , Walker B.
Published: June 2006

This study reports on the synthesis of peptides containing C‐terminal acylated gem‐diamines and their utilization for the preparation of irreversible inactivators of the serine and cysteine proteinases. We have succeeded in obtaining an inhibitor Acetyl‐Val‐Pro‐g‐Val‐CO‐O‐C6H4‐NO2 of neutrophil and pancreatic elastases that functions in a time‐dependent manner, indicative of the action of an irreversible inactivator, functioning, most probably, through the formation of a long‐lived acyl enzyme intermediate. In addition, we have demonstrated the irreversible inhibition of the cysteine proteinase bovine cathepsin B, by chloroacetyl and bromoacetyl derivatives of a dipeptide gem‐diamine, Cbz‐Phe‐g‐Ala‐CO‐CH2Hal (Hal = Br, Cl).
The pre‐M1 segment of the α1 subunit is a transduction element in the activation of the GABAA receptor
Authors: Keramidas Angelo , Kash Thomas L. , Harrison Neil L.
Published: June 2006

The binding of the neurotransmitter GABA induces conformational changes in the GABAA receptor (GABAAR), leading to the opening of a gate that controls ion permeation through an integral transmembrane pore. A number of structural elements within each subunit, located near the membrane interface, are believed to undergo relative movements during this activation process. In this study, we explored the functional role of the β‐10 strand (pre‐M1 segment), which connects the extracellular domain to the transmembrane domain. In α1β2γ2s GABAARs, analysis of the 12 residues of the β‐10 strand in the α1 subunit proximal to the first transmembrane domain identified two residues, α1V212 and α1K220, in which mutations produced rightward shifts in the GABA concentration–response relationship and also reduced the relative efficacy of the partial agonist, piperidine‐4‐sulphonic acid. Ultra‐fast agonist techniques were applied to mutant α1(K220A)β2γ2s GABAARs and revealed that the macroscopic functional deficit in this mutant could be attributed to a slowing of the opening rate constant, from ∼1500 s−1 in wild‐type (WT) channels to ∼730 s−1 in the mutant channels, and a reduction in the time spent in the active state for the mutant. These changes were accompanied by a decrease in agonist affinity, with half‐maximal activation rates achieved at 0.77 mm GABA in WT and 1.4 mm GABA in the α1(K220A)β2γ2s channels. The β‐10 strand (pre‐M1 segment) emerges, from this and other studies, as a key functional component in the activation of the GABAAR.
An Effective Numerical Approach for Multiple Void-Crack Interaction
Authors: Yan Xiangqiao
Published: June 2006

This paper presents a numerical approach to modeling a general system containing multiple interacting cracks and voids in an infinite elastic plate under remote uniform stresses. By extending Bueckner’s principle suited for a crack to a general system containing multiple interacting cracks and voids, the original problem is divided into a homogeneous problem (the one without cracks and voids) subjected to remote loads and a multiple void-crack problem in an unloaded body with applied tractions on the surfaces of cracks and voids. Thus the results in terms of the stress intensity factors (SIFs) can be obtained by considering the latter problem, which is analyzed easily by means of the displacement discontinuity method with crack-tip elements (a boundary element method) proposed recently by the author. Test examples are included to illustrate that the numerical approach is very simple and effective for analyzing multiple crack/void problems in an infinite elastic plate. Specifically, the numerical approach is used to study the microdefect-finite main crack linear elastic interaction. In addition, complex crack problems in infinite/finite plate are examined to test further the accuracy and robustness of the boundary element method.
Constitutive Modeling of the Finite Deformation Behavior of Membranes Possessing a Triangulated Network Microstructure
Authors: Arslan M. , Boyce M. C.
Published: June 2006

The mechanical behavior of the membrane of the red blood cell is governed by two primary microstructural features: the lipid bilayer and the underlying spectrin network. The lipid bilayer is analogous to a two-dimensional fluid in that it resists changes to its surface area, yet poses little resistance to shear. A skeletal network of spectrin molecules is cross-linked to the lipid bilayer and provides the shear stiffness of the membrane. Here, a general continuum level constitutive model of the large stretch behavior of the red blood cell membrane that directly incorporates the microstructure of the spectrin network is developed. The triangulated structure of the spectrin network is used to identify a representative volume element (RVE) for the model. A strain energy density function is constructed using the RVE together with various representations of the underlying molecular chain force-extension behaviors where the chain extensions are kinematically determined by the macroscopic deformation gradient. Expressions for the nonlinear finite deformation stress-strain behavior of the membrane are obtained by proper differentiation of the strain energy function. The stress-strain behaviors of the membrane when subjected to tensile and simple shear loading in different directions are obtained, demonstrating the capabilities of the proposed microstructurally detailed constitutive modeling approach in capturing the small to large strain nonlinear, anisotropic mechanical behavior. The sources of nonlinearity and evolving anisotropy are delineated by simultaneous monitoring of the evolution in microstructure including chain extensions, forces and orientations as a function of macroscopic stretch. The model captures the effect of pretension on the mechanical response where pretension is found to increase the initial modulus and decrease the limiting extensibility of the networked membrane.
Transient Response of a Finite Bimaterial Plate Containing a Crack Perpendicular to and Terminating at the Interface
Authors: Li Xian-Fang , Xu L. Roy
Published: June 2006

The transient response of a finite bimaterial plate with a crack perpendicular to and terminating at the interface is analyzed for two types of boundaries (free-free and clamped-clamped). The crack surface is loaded by arbitrary time-dependent antiplane shear impact. The mixed initial-boundary value problem is reduced to a singular integral equation of a generalized Cauchy kernel for the crack tearing displacement density or screw dislocation density. The Gauss-Jacobi quadrature technique is employed to numerically solve the singular integral equation, and then the dynamic stress intensity factors are determined by implementing a numerical inversion of the Laplace transform. As an example, numerical calculations are carried out for a cracked bimaterial plate composed of aluminum (material I) and epoxy or steel (material II). The effects of material properties, geometry, and boundary types on the variations of dynamic stress intensity factors are discussed in detail. Results indicate that an overshoot of the normalized stress intensity factor of the crack tip at the interface decreases for a cracked bimaterial plate, and the occurrence of which is delayed for a cracked aluminum/epoxy plate compared to a pure aluminum plate with the same crack.
Unified Probabilistic Approach for Model Updating and Damage Detection
Authors: Yuen Ka-Veng , Beck James L. , Katafygiotis Lambros S.
Published: June 2006

A probabilistic approach for model updating and damage detection of structural systems is presented using noisy incomplete input and incomplete response measurements. The situation of incomplete input measurements may be encountered, for example, during low-level ambient vibrations when a structure is instrumented with accelerometers that measure the input ground motion and the structural response at a few instrumented locations but where other excitations, e.g., due to wind, are not measured. The method is an extension of a Bayesian system identification approach developed by the authors. A substructuring approach is used for the parameterization of the mass, damping and stiffness distributions. Damage in a substructure is defined as stiffness reduction established through the observation of a reduction in the values of the various substructure stiffness parameters compared with their initial values corresponding to the undamaged structure. By using the proposed probabilistic methodology, the probability of various damage levels in each substructure can be calculated based on the available dynamic data. Examples using a single-degree-of-freedom oscillator and a 15-story building are considered to demonstrate the proposed approach.
Multidomain Topology Optimization for Structural and Material Designs
Authors: Ma Zheng-Dong , Kikuchi Noboru , Pierre Christophe , Raju Basavaraju
Published: June 2006

A multidomain topology optimization technique (MDTO) is developed, which extends the standard topology optimization method to the realm of more realistic engineering design problems. The new technique enables the effective design of a complex engineering structure by allowing the designer to control the material distribution among the subdomains during the optimal design process, to use multiple materials or composite materials in the various subdomains of the structure, and to follow a desired pattern or tendency for the material distribution. A new algorithm of Sequential Approximate Optimization (SAO) is proposed for the multidomain topology optimization, which is an enhancement and a generalization of previous SAO algorithms (including Optimality Criteria and Convex Linearization methods, etc.). An advanced substructuring method using quasi-static modes is also introduced to condense the nodal variables associated with the multidomain topology optimization problem, especially for the nondesign subdomains. The effectiveness of the new MDTO approach is demonstrated for various design problems, including one of “structure-fixture simultaneous design,” one of “functionally graded material design,” and one of “crush energy management.” These case studies demonstrate the potential significance of the new capability developed for a wide range of engineering design problems.
Circumferential Waves of Infinite Hollow Poroelastic Cylinders
Authors: Tajuddin M. , Shah S. Ahmed
Published: June 2006

Employing Biot’s theory of wave propagation in liquid saturated porous media, the frequency equation of circumferential waves for a permeable and an impermeable surface of an infinite hollow poroelastic cylinder is derived in the presence of dissipation and then discussed. Phase velocity and attenuation are determined for different dissipations and then discussed. By ignoring liquid effects, the results of purely elastic solid are obtained as a special case.
Stability and Andronov-Hopf Bifurcation of Steady-State Motion of
Rotor System Partly Filled With Liquid: Continuous and Discrete
Models
Authors: Derendyaev N. V. , Vostrukhov A. V. , Soldatov I. N.
Published: June 2006

In this paper, a new method for investigation of dynamics of fluid-filled rotor systems is presented. The method consists of development of finite degrees-of-freedom (discrete) models for the rotor systems. The discrete models are physically justified and demonstrative. Being described by the system of ordinary differential equations, they allow one to employ powerful tools of the theoretical mechanics and oscillation theory. The method is applied to the case of the plane model of the rotor system partly filled with incompressible liquid. Both the continuous and discrete models are considered. The main attention is paid to the latter model. The discrete model consists of a disk symmetrically fixed on the shaft (Laval scheme), the ends of which are in viscoelastic bearings, and a ring sliding over the disk with friction. The centers of the disk and ring are elastically connected. The disk models the rotor, while the ring describes the liquid filling. When the ring is sliding over the disk surface, an interaction force arises that is diverted from the direction of the relative velocity at the contact points. It is demonstrated that an appropriate choice of the parameters of the discrete model allows one to determine the stability domain of the steady-state rotation of the rotor in the plane of the parameters of the shaft bearings with an excellent accuracy. It is found out that when the parameters overstep the limits of the stability domain, the Andronov-Hopf bifurcation occurs: a periodic motion of a kind of a circular precession arises from the steady-state rotation regime either “softly” or “hardly.”
The Effects of Vibrations on Particle Motion Near a Wall in a Semi-Infinite Fluid Cell
Authors: Hassan Samer , Kawaji Masahiro , Lyubimova Tatyana P. , Lyubimov Dmitry V.
Published: June 2006

The effects of small vibrations on a particle-fluid system relevant to material processing such as crystal growth in space have been investigated experimentally and theoretically. An inviscid model for a spherical particle of radius, R0, suspended by a thin wire and moving normal to a cell wall in a semi-infinite liquid-filled cell subjected to external horizontal vibrations, was developed to predict the vibration-induced particle motion under normal gravity. The wall effects were studied by varying the distance between the equilibrium position of the particle and the nearest cell wall, H. The method of images was used to derive the equation of motion for the particle oscillating in an inviscid fluid normal to the nearest cell wall. The particle amplitude in a semi-infinite cell increased linearly with the cell vibration amplitude as expected from the results for an infinite cell, however, the particle amplitude also changed with the distance between the equilibrium position of the particle and the nearest wall. The particle amplitude was also found to increase or decrease depending on whether the cell vibration frequency was below or above the resonance frequency, respectively. The theoretical predictions of the particle amplitudes in the semi-infinite cell agreed well with the experimental data, where the effect of the wall proximity on the particle amplitude was found to be significant for (H∕R0<2) especially near the resonance frequency. Experiments performed at high frequencies well above the resonance frequency showed that the particle amplitude reaches an asymptotic value independent of the wire length.
Isotropic Clamped-Free Thin Annular Circular Plate Subjected to a Concentrated Load
Authors: Adewale Ajayi O.
Published: June 2006

The problem of an isotropic annular plate clamped along one edge and free at the other and subjected to a concentrated load is solved by a series approximation. The continuity conditions of deflection, slope, shear and radial moments at the radius of load application are satisfied. Variations of deflection coefficient, radial moment coefficients and shear coefficients with radius and angle are presented.
Post-bauckling and Vibration of Heavy Beam on Horizontal or Inclined Rigid Foundation
Authors: Santillan S. T. , Virgin L. N. , Plaut R. H.
Published: June 2006

A slender, straight beam resting on a flat, rigid foundation does not buckle when subjected to a compressive load, since the load cannot overcome the effect of the beam’s weight. However, it buckles if its ends are moved toward each other. Post-buckling of such a beam is examined, both theoretically and experimentally, for horizontal and inclined foundations. The beam is modeled as an elastica, and equilibrium states with large deflections are computed, including cases in which self-contact occurs. Frequencies and mode shapes for small vibrations about equilibrium are also determined. Agreement between the theoretical and experimental results is very good.
Lattice Boltzmann Modeling of Subcontinuum Energy Transport in Crystalline and Amorphous Microelectronic Devices
Authors: Escobar Rodrigo , Smith Brian , Amon Cristina
Published: June 2006

Numerical simulations of time-dependent energy transport in semiconductor thin films are performed using the lattice Boltzmann method applied to phonon transport. The discrete lattice Boltzmann method is derived from the continuous Boltzmann transport equation assuming first gray dispersion and then nonlinear, frequency-dependent phonon dispersion for acoustic and optical phonons. Results indicate that a transition from diffusive to ballistic energy transport is found as the characteristic length of the system becomes comparable to the phonon mean free path. The methodology is used in representative microelectronics applications covering both crystalline and amorphous materials including silicon thin films and nanoporous silica dielectrics. Size-dependent thermal conductivity values are also computed based on steady-state temperature distributions obtained from the numerical models. For each case, reducing feature size into the subcontinuum regime decreases the thermal conductivity when compared to bulk values. Overall, simulations that consider phonon dispersion yield results more consistent with experimental correlations.
Micron and Submicron-Scale Characterization of Interfaces in Thermal Interface Material Systems
Authors: Gowda Arun , Esler David , Tonapi Sandeep , Zhong Annita , Srihari K. , Schattenmann Florian
Published: June 2006

One of the key challenges in the thermal management of electronic packages are interfaces, such as those between the chip and heat spreader and the interface between a heat spreader and heat sink or cold plate. Typically, thermal interfaces are filled with materials such as thermal adhesives and greases. Interface materials reduce the contact resistance between the mating heat generating and heat sinking units by filling voids and grooves created by the nonsmooth surface topography of the mating surfaces, thus improving surface contact and the conduction of heat across the interface. However, micron and submicron voids and delaminations still exist at the interface between the interface material and the surfaces of the heat spreader and semiconductor device. In addition, a thermal interface material (TIM) may form a filler-depleted and resin-rich region at the interfaces. These defects, though at a small length scale, can significantly deteriorate the heat dissipation ability of a system consisting of a TIM between a heat generating surface and a heat dissipating surface. The characterization of a freestanding sample of TIM does not provide a complete understanding of its heat transfer, mechanical, and interfacial behavior. However, system-level characterization of a TIM system, which includes its freestanding behavior and its interfacial behavior, provides a more accurate understanding. While, measurement of system-level thermal resistance provides an accurate representation of the system performance of a TIM, it does not provide information regarding the physical behavior of the TIM at the interfaces. This knowledge is valuable in engineering interface materials and in developing assembly process parameters for enhanced system-level thermal performance. Characterization of an interface material between a silicon device and a metal heat spreader can be accomplished via several techniques. In this research, high-magnification radiography with computed tomography, acoustic microscopy, and scanning electron microscopy were used to characterize various TIM systems. The results of these characterization studies are presented in this paper. System-level thermal performance results are compared to physical characterization results.
Boiling Heat Transfer Enhancement Using a Submerged, Vibration-Induced Jet
Authors: Tillery Steven W. , Heffington Samuel N. , Smith Marc K. , Glezer Ari
Published: June 2006

In this paper we describe a new two-phase cooling cell based on channel boiling and a vibration-induced liquid jet whose collective purpose is to delay the onset of critical heat flux by forcibly dislodging the small vapor bubbles that form on the heated surface during nucleate boiling and propelling them into the cooler bulk liquid within the cell. The submerged turbulent vibration-induced jet is generated by a vibrating piezoelectric diaphragm operating at resonance. The piezoelectric driver induces pressure oscillations in the liquid near the surface of the diaphragm, resulting in the time-periodic formation and collapse of cavitation bubbles that entrain surrounding liquid and generate a strong liquid jet. The resultant jet is directed at the heated surface in the channel. The jet enhances boiling heat transfer by removing attached vapor bubbles that insulate the surface and provides additional forced convection heat transfer on the surface. A small cross flow maintained within the cell increases heat transfer even further by sweeping the bubbles downstream, where they condense. In addition, the cross flow keeps the temperature of the liquid within the cell regulated. In the present experiments, the cell dimensions were 51×25×76mm and water was the working liquid. Heat fluxes above 300W∕cm2 were obtained at surface temperatures near 150°C for a horizontal cell.
Distribution of DArT, AFLP, and SSR markers in a genetic linkage map of a doubled-haploid hexaploid wheat population
Authors: Semagn Kassa , Bjørnstad Åsmund , Skinnes Helge , Marøy Anne Guri , Tarkegne Yalew , William Manilal
Published: June 2006

A genetic linkage mapping study was conducted in 93 doubled-haploid lines derived from a cross between Triticum aestivum L. em. Thell 'Arina' and a Norwegian spring wheat breeding line, NK93604, using diversity arrays technology (DArT), amplified fragment length polymorphism (AFLP), and simple sequence repeat (SSR) markers. The objective of this study was to understand the distribution, redundancy, and segregation distortion of DArT markers in comparison with AFLP and SSR markers. The map contains a total of 624 markers with 189 DArTs, 165 AFLPs and 270 SSRs, and spans 2595.5 cM. All 3 marker types showed significant (p < 0.01) segregation distortion, but it was higher for AFLPs (24.2%) and SSRs (22.6%) than for DArTs (13.8%). The overall segregation distortion was 20.4%. DArTs showed the highest frequency of clustering (27.0%) at < 0.5 cM intervals between consecutive markers, which is 3 and 15 times higher than SSRs (8.9%) and AFLPs (1.8%), respectively. This high proportion of clustering of DArT markers may be indicative of gene-rich regions and (or) the result of inclusion of redundant clones in the genomic representations, which was supported by the presence of very high correlation coefficients (r > 0.98) and multicollinearity among the clustered markers. The present study is the first to compare the utility of DArT with AFLP and SSR markers, and the present map has been successfully used to identify novel QTLs for resistance to Fusarium head blight and powdery mildew and for anther extrusion, leaf segment incubation, and latency.Key words: 'Arina', diversity arrays technology, double haploid, genetic map, marker clustering, microsatellite.
Use of a large-scale Triticeae expressed sequence tag resource to reveal gene expression profiles in hexaploid wheat (Triticum aestivumL.)
Authors: Chao S , Lazo G R , You F , Crossman C C , Hummel D D , Lui N , Laudencia-Chingcuanco D , Anderson J A , Close T J , Dubcovsky J , Gill B S , Gill K S , Gustafson J P , Kianian S F , Lapitan N L.V , Nguyen H T , Sorrells M E , McGuire P E , Qualset C O , Anderson O D
Published: June 2006

The US Wheat Genome Project, funded by the National Science Foundation, developed the first large public Triticeae expressed sequence tag (EST) resource. Altogether, 116 272 ESTs were produced, comprising 100 674 5′ ESTs and 15 598 3′ ESTs. These ESTs were derived from 42 cDNA libraries, which were created from hexaploid bread wheat (Triticum aestivum L.) and its close relatives, including diploid wheat (T. monococcum L. and Aegilops speltoides L.), tetraploid wheat (T. turgidum L.), and rye (Secale cereale L.), using tissues collected from various stages of plant growth and development and under diverse regimes of abiotic and biotic stress treatments. ESTs were assembled into 18 876 contigs and 23 034 singletons, or 41 910 wheat unigenes. Over 90% of the contigs contained fewer than 10 EST members, implying that the ESTs represented a diverse selection of genes and that genes expressed at low and moderate to high levels were well sampled. Statistical methods were used to study the correlation of gene expression patterns, based on the ESTs clustered in the1536 contigs that contained at least 10 5′ EST members and thus representing the most abundant genes expressed in wheat. Analysis further identified genes in wheat that were significantly upregulated (p < 0.05) in tissues under various abiotic stresses when compared with control tissues. Though the function annotation cannot be assigned for many of these genes, it is likely that they play a role associated with the stress response. This study predicted the possible functionality for 4% of total wheat unigenes, which leaves the remaining 96% with their functional roles and expression patterns largely unknown. Nonetheless, the EST data generated in this project provide a diverse and rich source for gene discovery in wheat.Key words: Expressed sequence tags, ESTs, gene expression profiles, wheat, Triticeae.
Mutant α-synuclein-induced degeneration is reduced by parkin in a fly model of Parkinson's disease
Authors: Haywood Annika F.M , Staveley Brian E
Published: June 2006

Parkinson's disease (PD) patients show a characteristic loss of motor control caused by the degeneration of dopaminergic neurons. Mutations in the genes that encode α-synuclein and parkin have been linked to inherited forms of this disease. The parkin protein functions as a ubiquitin ligase that targets proteins for degradation. Expression of isoforms of human α-synuclein in the Drosophila melanogaster nervous system forms the basis of an excellent genetic model that recapitulates phenotypic and behavioural features of PD. Using this model, we analysed the effect of parkin co-expression on the climbing ability of aging flies, their life span, and their retinal degeneration. We have determined that co-expression of parkin can suppress phenotypes caused by expression of mutant α-synuclein. In the developing eye, parkin reduces retinal degeneration. When co-expressed in the dopaminergic neurons, the ability to climb is extended over time. If conserved in humans, we suggest that upregulation of parkin may prove a method of suppression for PD induced by mutant forms of α-synuclein.Key words: parkin, α-synuclein, Drosophila melanogaster, model of Parkinson's disease.
Axial loading tests on short and long hollow structural steel columns retrofitted using carbon fibre reinforced polymers
Authors: Shaat Amr , Fam Amir
Published: June 2006

This paper describes the behaviour of axially loaded short and long square hollow structural section (HSS) columns, strengthened with carbon fibre reinforced polymer (CFRP) sheets. Twenty-seven short-column and five long-column HSS specimens were tested. The effect of CFRP sheet orientation in the longitudinal and transverse directions was studied for short columns. For long columns, CFRP sheets were oriented in the longitudinal direction only. A maximum strength gain of 18% was achieved for short columns with two transverse CFRP layers. For long columns, the maximum strength gain of 23% was achieved with three longitudinal CFRP layers applied on four sides. In all CFRP-strengthened long columns, lateral deflections were reduced. Strength gain in long columns was highly dependent on the column's imperfection. As such, no correlation was established between strength gain and number of CFRP layers. CAN/CSA 16-01 equation was modified to account for CFRP through transformed section analysis so that they could be used to predict the axial-load capacity of long columns.Key words: retrofit, steel, HSS, column, FRP, carbon, buckling, strength, stiffness.
Redistribution of longitudinal moments in straight, continuous concrete slab – steel girder composite bridges
Authors: Razaqpur A Ghani , Esfandiari Afshin
Published: June 2006

The effect of loading and geometric parameters on the transverse and longitudinal redistribution of moments in continuous composite bridges, comprising a concrete slab on parallel steel girders, is investigated with the nonlinear finite element method. Fifty bridges are analyzed over their entire range of loading up to failure, and their moment redistribution factors are determined and compared with the relevant predictions of the Canadian Highway Bridge Design Code (CHBDC) and the AASHTO LRFD Bridge Design Specifications. The parameters studied included truck position along the bridge, number of loaded lanes, bridge width, number of girders, slab thickness, degree of composite action, and presence of diaphragms. The study reveals that among the preceding parameters only the number of loaded lanes and the bridge width significantly affect transverse redistribution of moments at ultimate limit state (ULS). However, most of the preceding parameters affect longitudinal redistribution at ULS. Finally, it is demonstrated that plastic analysis of composite multi-girder continuous bridges, treated as an equivalent beam, provides a reasonable estimate of their longitudinal moment redistribution capacity at ULS. It is demonstrated that the actual load-carrying capacity of a composite bridge may be more than 50% higher than that predicted by the CHBDC or AASHTO code. Such higher predicted capacity may obviate the need for retrofit in some cases.Key words: analysis, bridge, composite, concrete, distribution, finite element, inelastic, load, steel.
Nonorthogonal solution for thin-walled members – applications and modelling considerations
Authors: Erkmen R Emre , Mohareb Magdi
Published: June 2006

In a companion paper (R.E. Erkmen and M. Mohareb. 2006. Canadian Journal of Civil Engineering, 33: 421–439.), three finite elements based on the Vlasov thin-walled beam theory were formulated using a nonorthogonal coordinate system. Although the associated derivations are more elaborate than in more conventional solutions based on orthogonal coordinates, the new elements offer more modelling capabilities and flexibility in modelling structural steel members, a feature that is illustrated in this paper. In this context, the current paper presents four details in steel construction that were conveniently modelled within the new solution scheme. The applications involve thin-walled members with coped flanges, rectangular holes reinforced with longitudinal stiffeners, and eccentric supports. Comparisons with established shell finite element models using ABAQUS suggest the validity of the new solution. Key words: open sections, finite element analysis, thin-walled members, coped flanges, rectangular holes, eccentric supports.
Development of quality criteria based on a toxicological characterization of fertilizing residuals
Authors: Chassé Raynald , Delbaen Sandrine , Hébert Marc
Published: June 2006

Toxicity tests were used to evaluate the environmental toxicity of municipal and industrial residuals compared to cow and hog manures. The goal was to evaluate the impact of chemicals that are either potentially present but not routinely analyzed, or unknown. Four toxicity tests were used: germination and growth of barley (Hordeum vulgare), mortality of Daphnia magna, light production inhibition of the bioluminescent bacteria Vibrio fischeri, and mortality of earthworms (Eisenia andrei). Twenty-five samples of residuals and 20 samples of manures were sampled and mixed into standardized soil samples. Part of the amended soil was used for barley tests whereas a water extract of the rest was used for toxicity tests with Daphnia and Vibrio. The worm tests were performed with fertilizing residuals and manures not mixed with soil. The toxicity varied according to the amount of manure or fertilizing residual added to the soil samples. At agronomic rates, toxicity of most of the residuals was low or even negative (stimulation of barley growth). A set of toxicological tests and criteria is proposed to assess if a given residual presents an elevated toxicity as compared to that of manures. Results of this study were used by the Ministère du Développement durable, de l'Environnement et des Parcs (MDDEP) to establish toxicity criteria in its guidelines for the valorization of fertilizing residuals. Key words: biosolid, sludge, lime residuals, toxicity test, manure, residual, toxicity, criteria.
Impact of organic waste amendments on soil hydraulic properties and on water partitioning
Authors: Unc Adrian , Goss Michael J
Published: June 2006

Land application of organic wastes can lead to contamination of ground- and surface waters. The pathway taken by particulate contaminants, such as microorganisms, is entirely dependent on the partitioning of the incoming rain or irrigation water. The soil hydraulic properties are critical in determining the infiltration:runoff water-partitioning ratio. Components of the land applied organic waste can modify the soil hydraulic properties and thus alter this ratio. It was shown that liquid manure impacted matrix and macropore flow differently; favouring the later through obstruction of the former. In contrast solid manure favoured matrix flow over macropore flow thereby increasing the water storage in soil, which tended to reduce the likelihood of runoff. The relationships between soil hydraulic conductivity and soil textural and structural properties in repacked soil columns was unrelated to the relationships obtained for the same soils maintained in their natural undisturbed field state. Key words: organic waste, manure, soil type, hydraulic conductivity, water partitioning, transport, contaminants.
Compost environmental protection standards in Canada
Authors: Ge Bo , McCartney Daryl , Zeb Jehan
Published: June 2006

The purpose of this paper was to summarize and compare Canadian environmental protection standards for compost. The paper describes the national and provincial organizations responsible for compost quality control in Canada. Discussions were organized under the key environmental protection criteria: maturity, trace elements, time–temperature requirements, pathogens (indicator organisms), foreign matter, and trace organics. A total of six organizations (three across Canada and three provincial) currently have distinct standards. Recent efforts to harmonize the standards have reduced the disparity between the various organizations. Key words: compost, Canada, standards, environmental protection, criteria, solid waste management.
Use of bark and combined paper sludge for the revegetation of bark-covered land
Authors: Beauchamp Chantal J , Camiré Claude , Chalifour François-P.
Published: June 2006

This study investigated the use of bark and combined paper sludge to develop a suitable plant growth substrate and to establish a vegetation cover on bark-covered land. Field experiments were established to determine the best plant growth medium, plant mixtures, and fertilization program. The best soil cover consisted of 2.5 cm of combined paper sludge on top of 2.5 cm of black bark. On this soil cover, the Savoureux mixture in combination with birdsfoot trefoil (Lotus corniculatus L.), Lab02 in mixture with MR77, and birdsfoot trefoil in mixture with bromegrass (Bromus inermis L.) gave good vegetation growth and yields. For birdsfoot trefoil over all soil covers, the phosphorus and potassium fertilizations were required at 140 kg P2O5/ha and 160 kg K2O/ha, respectively. These results suggest that combined paper sludge and black bark can be used as topsoil to favor plant establishment on bark-covered land. Key words: topsoil, paper sludge, bark, birdsfoot trefoil, bromegrass, fertilization, NO3–-N, phosphorus.
Composting of municipal biosolids: effect of bulking agent particle size on operating performance
Authors: Raichura Ash , McCartney Daryl
Published: June 2006

Woodchips, prepared from wood waste obtained from a pallet manufacturer, were used to determine the effect of bulking agent particle size on compost pile performance. The three treatments investigated used coarse, medium, or fine woodchips. Characteristic particle sizes were 40, 13, and 5.2 mm for the coarse, medium, and fine material, respectively. All recipes were made using one part biosolids to 2.5 parts woodchips (v:v) at a target moisture content of 60%. Finer woodchips resulted in thermophilic temperature values being reached sooner, being sustained for a longer time (>95 d), and recovering more quickly after rainfall events. Finer woodchips also resulted in lower moisture loss over the experimental period. Based on the experimental observations, it was assumed decreased tortuosity in the coarse woodchip material led to higher ventilation rates as compared to the finer material. Further experimental work is required to confirm this. The authors' recommend operators characterize feedstock bulking agent particle size distribution, particularly at facilities purchasing bulking agents for their operations. Key words: compost, municipal biosolids, woodchips, particle size, bulking agent, temperature.
The effect of woodland proximity and wetland characteristics on larval anuran assemblages in an agricultural landscapeThis is contribution No. 82 of the MacArthur Agro-Ecology Research Center.
Authors: Babbitt K.J. , Baber M.J. , Brandt L.A.
Published: June 2006

Changes to landscapes for agricultural activities often result in reduction and fragmentation of forested habitat. Land conversion for cattle ranching in south-central Florida has resulted in increases in pasture land interspersed with remnant patches of hardwood hammock. To examine the importance of these hammocks to anurans, we sampled 78 seasonally inundated wetlands to examine the relative importance of proximity of hardwood hammock patches (>20 ha) and wetland characteristics and used generalized linear models to determine which factors had a significant effect on larval anuran species richness or abundance. Species richness was significantly influenced by pH, conductivity, and water depth. Proximity to hammock did not influence species richness; however, assemblage composition differed between wetlands near hammocks and wetlands surrounded by pasture. Barking treefrogs ( Hyla gratiosa LeConte, 1856), pine woods treefrogs ( Hyla femoralis Bosc in Daudin, 1800), and oak toads ( Bufo quercicus Holbrook, 1840) bred only in wetlands within 20, 50, and 200 m of hammocks, respectively. Factors influencing tadpole abundances were species-specific. Retention of seasonally inundated wetlands proximal to large hammocks on ranchlands can provide important habitat for supporting a diverse assemblage of anurans.
Phylogeny of members of the rockfish (Sebastes) subgenusPteropodusand their relatives
Authors: Li Z. , Gray A.K. , Love M.S. , Asahida T. , Gharrett A.J.
Published: June 2006

The Sebastes Cuvier, 1829 subgenus Pteropodus Eigenmann and Beeson, 1893 includes six species from the northeastern Pacific Ocean (NEP) and four species from the northwestern Pacific Ocean (NWP). Several NEP species assigned to other subgenera are similar to NEP Pteropodus species. Restriction site variation in the mitochondrial NADH dehydrogenase subunit 3 and 4 genes and the 12S and 16S ribosomal RNA genes were used to evaluate their relationships. Phylogenetic reconstruction showed that six NEP species of Pteropodus formed a monophyletic group that also included three NEP species currently assigned to other subgenera: Sebastes atrovirens (Jordan and Gilbert, 1880) (subgenus Mebarus Matsubara, 1943) and Sebastes auriculatus Girard, 1854 and Sebastes dalli (Eigenmann and Beeson, 1894) (both subgenus Auctospina (Eigenmann and Beeson, 1894)). The small average nucleotide divergence (0.0124 per nucleotide) observed among members of this group of species was similar to that observed among species of the monophyletic subgenus Sebastomus Gill, 1864 (0.0089 per nucleotide). The NWP species of Pteropodus did not cluster with their NEP consubgeners but, generally, were similar to other NWP species. We recommend that S. atrovirens, S. auriculatus, and S. dalli be included in subgenus Pteropodus with the other NEP species and that the NWP species of Pteropodus be removed from the subgenus. Our results indicate that the morphological characteristics used to distinguish species often may not be useful for phylogenetic analysis.
A comparison of coyote ecology after 25 years: 1978 versus 2003 This is Welder Wildlife Foundation contribution No. 651.
Authors: Young J.K. , Andelt W.F. , Terletzky P.A. , Shivik J.A.
Published: June 2006

Most ecological studies of coyotes are of short duration and studies are generally never repeated, thus the opportunity to compare changes in coyote ( Canis latrans Say, 1823) ecology over time is rare. We compared coyote home ranges, activity patterns, age, and diet at the Welder Wildlife Refuge in south Texas between 1978–1979 and 2003–2004 (25 years later). The Minta index of overlap between 1978 and 2003 home ranges was 51.7 ± 7.0 (n = 7), much greater than the Minta index value based on randomized tests (28.7 ± 8.6), indicating similar spatial patterns between time periods. The Minta index was 12.3 ± 6.2 (n = 7) for core areas, whereas the Minta index value based on randomized tests was 4.0 ± 3.0. Although overall diets were similar between 1978 and 2003, we detected some differences in prey species consumed. Activity patterns were similar between the two study periods, with peaks in movement occurring around sunrise and sunset. There was no difference in the mean age between the two populations (P = 0.44, n = 68, t[66] = 2.00). Our findings suggest that population features, such as home-range position and age structure, are similar between extended time periods, while individual-level patterns, such as the prey species consumed and distribution of locations within a home range, are dynamic and may reflect changes in the local environment.
In utero predator-induced responses in the viviparid snailBellamya chinensis
Authors: Prezant R.S. , Chapman E.J. , McDougall A.
Published: June 2006

Predator-induced defenses are well-known adaptive responses found in many marine and freshwater organisms. These responses usually occur in juveniles or actively growing adults and reduce the ability of a predator to consume its prey. We report a predator-induced response occurring in utero in the viviparid snail Bellamya chinensis (Gray, 1863) that results in significant changes in offspring number, shell size variability of released juveniles, and juvenile shell organic content. Water-borne cues derived from a predatory crayfish ( Orconectes limosus (Rafinesque, 1817)) induced a doubling of the number of offspring released; these newly born snails were generally smaller, though more variable in size, and possessed a greater shell organic content than controls. The generally smaller size of juveniles released in the presence of a predator reflects a faster rate of generation and passage through the uterus. These responses to the presence of a predator could be adaptive by decreasing predation pressure within a population or by reducing mortality following failed attacks.