bluuebunny/crossref_metadata_2025 huggingface dataset:
Behavior of Asphalt Concrete Mixtures in Triaxial Compression
Authors: Tan S-A , Low B-H , Fwa T-F
Published: May 2009

The triaxial compression test is one of the most common standard tests for determining the stress-strain behavior and strength parameters of soils under drained and undrained conditions. The use of the test method in asphaltic mixtures is less well known and seldom practiced. This paper describes the use of the triaxial compression test for asphaltic mixtures for determining their engineering properties such as the friction angle φ, the cohesion, c, and the elastic compression modulus, E. Effects of test temperatures, strain rate, and confining pressures on the compressive behavior of asphalt concrete were studied. The results showed that the friction angle is primarily a function of aggregate friction and interlocking, being independent of test temperature and strain rate. The cohesion, on the other hand, is largely dependent on the binder and fines mixture being sensitive to both test temperature and strain rate changes. The confining pressures have no influence on c and φ, but have significant influence on the compression modulus. E. The tests can be conducted at controlled temperatures, constant strain-rate, and confining pressures so as to allow the determination of the basic engineering stress-strain and strength properties of these materials under controlled environmental conditions. Using these properties, a constitutive plasticity model based on the Drucker-Prager yield condition can then be applied in an axisymmetric finite element model to describe the mechanical behavior of the asphaltic material in triaxial compression. Analysis shows that the plasticity model is able to describe the stress-strain behavior of the triaxial specimen to failure, predicting both the failure strain and the failure stress fairly accurately. Comparison of analysis with measured lateral deformation at failure also show good agreement. Thus it seems that a simple idealized elastic-perfectly-plastic constitutive model, whose parameters can be determined from a triaxial compression test at constant strain-rate, is adequate to describe the behavior of asphaltic mixtures, loaded in compression to failure.
Evaluation of Machinability Data
Authors: Jin L-Z , Sandström R
Published: May 2009

Systematic materials selection is essential to fulfill the design criteria. Reliable information on material properties, in turn, is a vital factor for approaching such an objective. The machinability of engineering metals, owing to the marked influence on the production costs, has to be taken into account in the process of materials selection. In an attempt to develop a method for estimating the machinability of engineering metals, machinability data collected from laboratory and literature are assessed. A rating system derived from the metal removal rate is proposed for estimating the relative machinability of carbon and alloy steels, stainless steels, and aluminum, copper, and magnesium alloys.
Introduction to the Sixth International Civil Aviation Security Conference (AVSEC'93)
Authors: Malotky LO
Published: May 2009

This introduction is provided as an overview of the papers included in this section of the Journal and to provide a context for reviewing these papers for the regular readers of the Journal. The Federal Aviation Administration (FAA) entered into a partnership with ASTM (Committee F-12 on Security Systems and Equipment) to conduct the Sixth International Civil Aviation Security Conference (AVSEC'93), held on 26–28 October 1993 in Washington, DC. The objective of this conference was to provide a forum for government, the aviation industry, and security service providers to exchange insights on solutions to the global challenge of providing safe and secure air travel.
Aviation Security Standards Development within ASTM Committee F-12 on Security Systems and Equipment
Authors: Draghetti PM
Published: May 2009

The structure and objectives of ASTM Committee F-12 on Security Systems and Equipment are described, with emphasis on its active components which involve aviation security. Pertinent existing standards and standards under development are discussed, particularly those within Subcommittees F12.10 on Systems, Products and Services, F12.50 on Locking Devices, and F12.60 on Controlled Access Security, Search and Screening Equipment
Instructions for a New Method of Inclusion Rating and Correlations with the Fatigue Limit
Authors: Murakami Y , Toriyama T , Coudert EM
Published: May 2009

Many inclusion rating methods already exist [1–6], some of which have been adopted as the standards for particular countries or industries. However, with the existing methods, it is difficult to evaluate the relationship between the fatigue limit and the type, size, or distribution of the inclusions.

Recent works have shown that inclusions behave as small defects and that the quantitative effect on the fatigue strength can be assessed from an evaluation of the square root of the projected area of the largest inclusion, on a plane perpendicular to the maximum principal stress direction. This parameter, designated √areamax, contained in a definite volume, can be evaluated using the statistics of extremes of the inclusion distribution.
Objective Evaluation of Surface Characteristics to Determine Smoothness of Pile Fabrics
Authors: Ajayi JO , Elder HM
Published: May 2009

Measurements of surface characteristics of pile fabrics by various methods to determine surface smoothness is reported. It is demonstrated that the number of peaks detected by methods using a roller, stylus, and friction traces is the best indicator of fabric smoothness. A negative correlation between this quantity and smoothness suggests that fabrics that yield more peaks are likely to be smoother than those with fewer peaks. This also agrees broadly with the results of friction measurement, lateral air flow, and microscopic measurements. Subjectively, judges found fabrics readily identifiable, but finding the right descriptive adjective for these differences remains a problem.
Effect of High Strain Rate on the Properties of PVC Pipe
Authors: Al-Bastaki NMS
Published: May 2009

Unplasticized PVC pipes were tested using static and dynamic testing conditions. The static test was performed by pressurizing the pipes at a strain rate of 1 × 10−4 s−1 and the dynamic test was carried out using a drop hammer apparatus at a strain rate of 8 s−1. The most pronounced influence of the high strain rate was a reduction in the failure hoop strain and an increase in the Young's modulus. An empirical formula was fitted to the stress-strain curves to represent the nonlinear and strain rate dependent behaviors.
Ability of Quality Assurance Tests to Detect Punctured Latex Condoms with Potential for Virus Penetration
Authors: Pierdominici VJB , Doucette JM , Coyne L , Cyr WH , Thomas DP , Lytle CD
Published: May 2009

How well do the quality assurance tests for latex condoms detect the potential for virus penetration? Defective condoms were created by puncturing with small acupuncture needles (120, 160 or 300 μm diameter) and were then tested by three quality assurance (QA) tests (the water leak test, a proposed electrical test, and the air burst test) and by a virus penetration test. Punctures (short tears) were detected by the FDA water leak test at the rate of 52% for punctures in the condom body and 9% in the condom tip; by the proposed ISO electrical leakage test (28% and 18% for body and tip, respectively); or by the ISO air burst test (30% and 5%, respectively). A standardized in vitro test of virus penetration under physiologic-based detected 100% and 48% of the punctures for body and tip, respectively. Thus the small tears created by puncture may not be detected in quality assurance tests, but would allow some virus penetration in the laboratory virus penetration test. A puncture in the tip of a condom was most likely to escape detection by each of the test methods,presumably because a puncture in that location does not open up as easily as elsewhere. Data with the air burst test indicated that raising the burst volume and/or burst pressure pass/fail limit would increase the likelihood of detecting a puncture defect to >93% when in the condom body, but to <15% when in the tip.
Comparison of Surface Texture Measurement by Stylus and Fiber Optic Transducers
Authors: Scott W , Donovan A
Published: May 2009

Signals obtained from a fiber optic transducer with an optical extender used to scan surfaces of varying texture been examined through analysis of their statistical functions, and compared with the signals obtained from a conventional contact profilometer. The amplitude/time and autocorrelation functions, probability density, and power spectra analyzed to assess the potential of technology where contact methods are impossible, such as the in-process monitoring of grinding wheel wear.
Testing of Sandwich Panels Under Uniform Pressure
Authors: Wennhage P , Zenkert D
Published: May 2009

The properties of a testing device for transverse loading of simply supported sandwich panels using a uniformly distributed load are investigated. Differences between hard and soft simply supported boundary conditions are verified. Shear stream gages are used to measure the shear stress in the core of the sandwich. The deflection, strains on the upper face, and the load distribution and measured on an isotropic sandwich panel and the same properties are calculated using an analytical method and a finite-element method (FEM). The boundary conditions are investigated by letting the FEM program calculate the solution for both soft and hard simply supported boundaries. The results show that the type of simply supported boundary conditions has a considerable effect on the solution. It is shown that the test panel used in this research better represents the soft boundary conditions. It is noted that the pressure can vary substantially close to the corners of the panel but is uniformly distributed over the central part of the panel.
Mechanical Properties of Laminated Veneer Lumber via Five-Point Bending Test
Authors: Bradtmueller JP , Hunt MO , Shook SM
Published: May 2009

The five-point bending test is shown to be an effective and efficient way of determining the mechanical properties of structural composite lumber. Shear strength, bending strength, shear-free Young's modulus of elasticity and shear modulus for both plank (flatwise) and joist (edgewise) orientations can be obtained with simple adjustments of the test configuration. Span or span-to-depth ratios are adjusted to produce either predominantly shear or bending failure. To determine elastic constants, a removable center support creates the necessary situation for both four-point bending and five-point bending. Use of a deflection yoke is especially important in determining the shear moduli. Results are reported for testing laminated veneer lumber. which was selected as representative of the evolving family of structural composite lumber products.
An International Survey of Small-Crack Research
Authors: Hamm RW , Johnson WS
Published: May 2009

A survey was conducted to determine the comment state of international research on small cracks. The survey consisted inquiries regarding the nature of the research, the materials studied,, the applications of the investigators' research, the smallest crack size monitored, the techniques used to monitor crack growth, the testing environment, the surface conditioning/preparation, and the models to predict crack growth. Survey participants were also asked to identify problem areas they were addressing with their research and other important unresolved questions regarding small cracks.

The results of the survey show that a wide range of materials, including metallics composites, rock, and bone, are currently under investigation for both basic research purposes and for particular applications. Researchers are able to monitor cracks smaller than I µm in length using one of or combinations of several different techniques.

Many crack growth models are being used to predict crack growth in these materials. The absence of a single unified crack growth model stems from the fact that the small-crack regime encompasses several different classifications, including microstructurally small cracks and mechanically small cracks. Each type of crack grows differently, thus requiring a different treatment.
Dynamic Calibration of Impact Test Instruments
Authors: Toropov AI , Grosso M
Published: May 2009

This paper proposes a new dynamic calibration procedure of the force measuring system used in instrumented impact test apparatus. The method involves calculation of the force calibration factor on the basis of energy values obtained executing the Charpy or Izod test for a pendulum device and on the basis of velocity measurements in a rebound test for the falling dart impact apparatus. The procedure is simple, quick, and has the advantage that calibration is performed under the same dynamic conditions as in a test itself. Moreover, it does not require any additional equipment other than that used for conventional impact test execution: an impact device, an instrumented tup, and a data acquisition system.
The Applicability of ASTM Standard Test Specimens to Fracture and Fatigue Crack Growth of Discontinuous-Fiber Composites
Authors: Salivar GC , Goree JG
Published: May 2009

A round-robin test program was performed to investigate the applicability of ASTM Standards E 399-90 and E 647-95a to discontinuous-fiber reinforced composite materials. Specifically, several standard test specimen geometries (the compact specimen, C(T), the bend specimen, SE(B), and the middle-tension specimen, M(T)) were investigated for use with 15 wt% SiC whisker-reinforced 2009 aluminum. E 399 fracture toughness tests showed that the compact specimen, C(T), does not provide useful data when the crack is oriented perpendicular to the whisker alignment direction (LT), Out-of-plane cracking with crack angles up to 60° was observed that resulted in invalid tests. The C(T) specimen did provide useful data when the crack was oriented parallel to the whisker alignment direction (TL). The SE(B) specimen had no problems with out-of-plane cracking and provided valid data in the E 399 tests.

The C(T) specimen was not useful in the E 647 fatigue crack growth rate tests in the LT orientation unless the specimens were side-grooved to maintain an in-plane crack. There were no problems with out-of-plane cracking in the C(T) specimen when it was used to text the TL orientation. The M(T) specimen maintained in-plane cracks and provided valid data in either the LT or the TL orientation tests.
X-ray Piping Diagnostic System
Authors: Kajiwara G
Published: May 2009

A diagnostic system was developed to cope with aged piping in a building. Working space and time is limited in a building, so X-rays were selected as the medium of inspection, and film was chosen as a detector. The method of calculating the thickness from the density of the film was studied, and a method to compare piping to be inspected with standard pipe and to determine thickness using an approximate curve was developed. The system was used for several hundred measurements. Error was found to be less than 10%.
Influence of X-Radiation on Behavior of Strain Gages
Authors: Palma ES , Lourenço OR , Gomes PTV
Published: May 2009

In this paper the performance of resistance strain gages in a radiation environment is examined. Values of apparent strain are measured by strain gages mounted on two kinds of backing materials (polyester and polyimide) as a function of X-ray flux. A comparison of the behavior of both types of strain gages is presented and discussed.
Effect of Vibration as a Cause of Leakage in Aluminum Beer Cans in Palletized Loads
Authors: Paul Singh S , Gorzynski M
Published: May 2009

This study investigated the effect of transport vibration on the number of leakers produced in aluminum beer cans. Two different types of can bottom profiles (2D and 3A) were tested. The cans were packaged in corrugated trays and paperboard cartons. The effect of double stacking versus single stacking was also tested. The results showed that the highest number of leakers was produced in the 3A can bottom profile, when packaged in corrugated trays and double stacked two pallets high. There was no significant effect of can location within a layer on the number of leakers.
Dissipated Energy of Composite Materials—Part I: Cyclic Dynamic Stress
Authors: Bledzki AK , Gassan J
Published: May 2009

This paper presents a method for the estimation of the vibratory fatigue strength of composite materials that is based on the accumulated dissipated energy. The accumulated dissipated energy was measured with a special measuring technique, which is able to catch quasi-continuously the mechanical properties of the tested samples. The curves of the accumulated dissipated energy were approximated with an equation that includes several parameters. These parameters were identified for experiments with different types of load and for samples with different contents of micropores. For samples that reach more than 106 load cycles, the accumulated dissipated energy in one-load-stage tests is a linear function. With this, the fatigue limit of the samples can be predicted.
Evaluation of Mechanical Properties of Functionally Graded Materials
Authors: Marur PR , Tippur HV
Published: May 2009

An experimental technique for evaluating the elastic properties of functionally graded materials (FGMs) is proposed. Ultrasonic pulse-echo measurements in conjunction with elastic impact testing permit determination of Young's modulus, Poisson's ratio, and the mass density of the material and its longitudinal variation. The details of the formulation of the technique and the implementation issues are discussed in this paper. These techniques have been applied successfully to evaluate the properties of a model functionally graded material.
Measurement of Fatigue-Creep Dynamic Back Stress and Strain Rate Equation of a Fe-Ni-Cr Alloy
Authors: He Q , Chen G , Zhang S
Published: May 2009

A new testing method for measurement of dynamic back stress for fatigue-creep interaction with predominant creep at high mean stress is developed according to the principle of dropped stress creep. A series of dropped stress creep tests were performed repeatedly until an unlimited extensive incubation with zero creep rate at a given dropped stress occurred. The stress causing zero creep rate is defined as fatigue-creep dynamic back stress. The developed method was used successfully to measure the dynamic back stress for fatigue-creep interaction with predominant creep. The dynamic effective stress could yield a better description of the strain rate equation for the fatigue-creep interaction at high mean stress. Mean stress plays a predominant role in determining fatigue-creep strain rate.
Data Acquisition and Analysis of Tensile Properties for Metal Matrix Composites
Authors: Roebuck B , Lord JD , Cooper PM , McCartney LN
Published: May 2009

Problems arise when existing standard tension tests are used for the measurement of the properties of metal matrix composites (MMCs), largely because the elastic limits in these materials are low due to intrinsic residual stresses. A new and validated data acquisition and analysis system has been developed to provide reference data for comparison with the results of two U.K. interlaboratory exercises on the tension test method for MMCs. Particular attention is paid to assessing an automatic system for calculating Young's modulus from the input data and using plots of secant or tangent modulus against stress or strain to present information on properties in a clear and succinct manner, and to methods for validating the software. The results of both interlaboratory exercises, on different types of MMCs, showed that the analysis system produced the smallest deviation from the mean.
Numerical Model of Primary Creep Deformation in a Novel Double Shear Specimen
Authors: Johnson NL , Earthman JC
Published: May 2009

Three-dimensional finite element calculations were performed for primary creep deformation in a novel double shear specimen. Two characteristic creep behaviors were considered: one in which the stress exponent, n, is equal to 3 and another in which n is equal to 5. Both models resulted in a quasi-stationary stress state in which the principal stresses change only slightly with time while the von Mises effective stress and principal facet stress reach essentially constant values. The uniformity of this quasi-stationary stress state throughout the gage section indicates that it may be used to characterize the overall stresses driving creep deformation and damage.
Application of Surface Fabrication to Strain Measurement in Nanometer Scale with the Scanning Tunneling Microscope
Authors: Miyahara K , Matsuoka S , Nagashima N , Masuda H
Published: May 2009

In this paper we describe the application of surface fabrication to the strain measurement in a nanometer scale with a scanning tunneling microscope (STM). In the electrical surface fabrication with the STM, hemispherical mounds whose radius and height were about 10 nm were created by applying a voltage pulse higher than 2.45 V between a gold STM tip and gold specimen. In the mechanical surface fabrication, indentations whose minimum depth was about 10 nm, were created by the contact of a conductive diamond tip with the gold specimen. The lattice of mounds or indentations was arranged in ten columns of ten rows at 45 nm pitch in the region of 450 × 450 nm. Comparing the two STM images before and after making a 50-nm-deep indentation on the lattice of small indentations, the displacement distribution was measured in the nanometer scale at each small indentation. Finally, strain distribution was calculated from the displacement distribution by using triangular elements.
Effects of Load-Distributed Width on Split Tension of Unnotched and Notched Cylindrical Specimens
Authors: Tang T
Published: May 2009

Unnotched and notched cylinders in split tension are analyzed. The load-distributed width has been shown to affect the stress and displacement distributions. Based on finite element analysis, linear elastic fracture mechanics (LEFM) formulas for the stress intensity factor KI, crack mouth opening displacement (CMOD), and the crack opening displacement (COD) profile for the split tension of notched cylinders are first provided in terms of load-distributed width as well as load magnitude, specimen size, and notch length. A formula expressing the effect of load-distributed width on maximum tensile stress in an unnotched cylinder is also provided.
Scoring of Precision Spur Gears
Authors: Budinski KG
Published: May 2009

A group of manufacturing machines employed precision spur gears as the timing mechanism for machine operations. These machines had worked successfully for about ten years with little or no problems with gear wear or deterioration. When new machines were brought on line with recently made gears there were immediate problems with gear tooth scoring.

A laboratory study was conducted to determine if metallurgical conditions were related to the gear scoring. Recent gears were made from a modification of the alloy used in early gears. The new alloy had been modified to make it more resistant to softening in coating operations. Reciprocating wear tests and galling tests were conducted to compare the tribological characteristics of the old and new gear steels.

It was determined that the threshold galling stress of the gear steels was strongly dependent on the hardness. The reciprocating wear tests indicated that the wear resistance was affected by the volume fraction of hard phases in the steels. The recommended short-term solution was to alter the tempering procedure for the steel to keep Rockwell C hardness above 60; the long-term solution was to change the gear material and lubrication.
Nondestructive Testing Techniques
Authors: DeNale R
Published: May 2009

This book represents a distillation of a multivolume document produced by Northrop Services, Inc. for the U.S. Army Missile Command. As such, the book is broad in scope, aimed at application-oriented personnel, and geared towards flaw detection.
Functional Connectivity of the Macaque Brain across Stimulus and Arousal States
Authors: Moeller Sebastian , Nallasamy Nambi , Tsao Doris Y. , Freiwald Winrich A.
Published: May 2009

Cortical networks generate temporally correlated brain activity. To clarify the functional significance of this correlated activity, we asked whether and how its structure depends on stimulus and arousal state. Using independent components analysis of macaque functional magnetic resonance imaging data, we identified a large number of brain networks that were strikingly reproducible across different visual stimulus contexts. Fewer networks were reproducible across alert and anesthetized brain states. Network complexity ranged from bilateral single-node networks to networks comprising multiple discrete nodes distributed over 3 cm of cortex; one network identified in our survey included parts of the temporal parietal occipital junction, dorsal premotor cortex, insula, and posterior cingulate cortex bilaterally. Our results reveal the wealth of spatially structured correlated networks throughout the brain in both alert and anesthetized monkeys, and show that anesthesia significantly alters the spatial structure of these networks.
Frontoparietal Cortex Controls Spatial Attention through Modulation of Anticipatory Alpha Rhythms
Authors: Capotosto Paolo , Babiloni Claudio , Romani Gian Luca , Corbetta Maurizio
Published: May 2009

A dorsal frontoparietal network, including regions in intraparietal sulcus (IPS) and frontal eye field (FEF), has been hypothesized to control the allocation of spatial attention to environmental stimuli. One putative mechanism of control is the desynchronization of electroencephalography (EEG) alpha rhythms (∼8–12 Hz) in visual cortex in anticipation of a visual target. We show that brief interference by repetitive transcranial magnetic stimulation (rTMS) with preparatory activity in right IPS or right FEF while subjects attend to a spatial location impairs identification of target visual stimuli ∼2 s later. This behavioral effect is associated with the disruption of anticipatory (prestimulus) alpha desynchronization and its spatially selective topography in parieto-occipital cortex. Finally, the disruption of anticipatory alpha rhythms in occipital cortex after right IPS- or right FEF-rTMS correlates with deficits of visual identification. These results support the causal role of the dorsal frontoparietal network in the control of visuospatial attention, and suggest that this is partly exerted through the synchronization of occipital visual neurons.
Number and Locations of Agonist Binding Sites Required to Activate Homomeric Cys-Loop Receptors
Authors: Rayes Diego , De Rosa María José , Sine Steven M. , Bouzat Cecilia
Published: May 2009

Homo-pentameric Cys-loop receptors contain five identical agonist binding sites, each formed at a subunit interface. To determine the number and locations of binding sites required to generate a stable active state, we constructed a receptor subunit with a mutation that disables the agonist binding site and a reporter mutation that alters unitary conductance and coexpressed mutant and nonmutant subunits. Although receptors with a range of different subunit compositions are produced, patch-clamp recordings reveal that the amplitude of each single-channel opening event reports the number and, for certain subunit combinations, the locations of subunits with intact binding sites. We find that receptors with three binding sites at nonconsecutive subunit interfaces exhibit maximal mean channel open time, receptors with binding sites at three consecutive or two nonconsecutive interfaces exhibit intermediate open time, and receptors with binding sites at two consecutive or one interface exhibit brief open time. Macroscopic recordings after rapid application of agonist reveal that channel activation slows and the extent of desensitization decreases as the number of binding sites per receptor decreases. The overall results provide a framework for defining mechanisms of activation and drug modulation for homo-pentameric Cys-loop receptors.
Estradiol Shapes Auditory Processing in the Adult Brain by Regulating Inhibitory Transmission and Plasticity-Associated Gene Expression
Authors: Tremere Liisa A. , Jeong Jin Kwon , Pinaud Raphael
Published: May 2009

Estradiol impacts a wide variety of brain processes, including sex differentiation, mood, and learning. Here we show that estradiol regulates auditory processing of acoustic signals in the vertebrate brain, more specifically in the caudomedial nidopallium (NCM), the songbird analog of the mammalian auditory association cortex. Multielectrode recordings coupled with local pharmacological manipulations in awake animals reveal that both exogenous and locally generated estradiol increase auditory-evoked activity in NCM. This enhancement in neuronal responses is mediated by suppression of local inhibitory transmission. Surprisingly, we also found that estradiol is both necessary and sufficient for the induction of multiple mitogen-activated protein kinase (MAPK)-dependent genes thought to be required for synaptic plasticity and memorization of birdsong. Specifically, we show that local blockade of estrogen receptors or aromatase activity in awake birds decrease song-induced MAPK-dependent gene expression. Infusions of estradiol in acoustically isolated birds induce transcriptional activation of these genes to levels comparable with song-stimulated animals. Our results reveal acute and rapid nongenomic functions for estradiol in central auditory physiology and suggest that such roles may be ubiquitously expressed across sensory systems.
Axonal Stress Kinase Activation and Tau Misbehavior Induced by Kinesin-1 Transport Defects
Authors: Falzone Tomás L. , Stokin Gorazd B. , Lillo Concepción , Rodrigues Elizabeth M. , Westerman Eileen L. , Williams David S. , Goldstein Lawrence S. B.
Published: May 2009

Many neurodegenerative diseases exhibit axonal pathology, transport defects, and aberrant phosphorylation and aggregation of the microtubule binding protein tau. While mutant tau protein in frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP17) causes aberrant microtubule binding and assembly of tau into filaments, the pathways leading to tau-mediated neurotoxicity in Alzheimer's disease and other neurodegenerative disorders in which tau protein is not genetically modified remain unknown. To test the hypothesis that axonal transport defects alone can cause pathological abnormalities in tau protein and neurodegeneration in the absence of mutant tau or amyloid β deposits, we induced transport defects by deletion of the kinesin light chain 1 (KLC1) subunit of the anterograde motor kinesin-1. We found that upon aging, early selective axonal transport defects in mice lacking the KLC1 protein (KLC1−/−) led to axonopathies with cytoskeletal disorganization and abnormal cargo accumulation. In addition, increased c-jun N-terminal stress kinase activation colocalized with aberrant tau in dystrophic axons. Surprisingly, swollen dystrophic axons exhibited abnormal tau hyperphosphorylation and accumulation. Thus, directly interfering with axonal transport is sufficient to activate stress kinase pathways initiating a biochemical cascade that drives normal tau protein into a pathological state found in a variety of neurodegenerative disorders including Alzheimer's disease.
The “Down Syndrome Critical Region” Is Sufficient in the Mouse Model to Confer Behavioral, Neurophysiological, and Synaptic Phenotypes Characteristic of Down Syndrome
Authors: Belichenko Nadia P. , Belichenko Pavel V. , Kleschevnikov Alexander M. , Salehi Ahmad , Reeves Roger H. , Mobley William C.
Published: May 2009

Down syndrome (DS) can be modeled in mice segmentally trisomic for mouse chromosome 16. Ts65Dn and Ts1Cje mouse models have been used to study DS neurobiological phenotypes including changes in cognitive ability, induction of long-term potentiation (LTP) in the fascia dentata (FD), the density and size of dendritic spines, and the structure of synapses. To explore the genetic basis for these phenotypes, we examined Ts1Rhr mice that are trisomic for a small subset of the genes triplicated in Ts65Dn and Ts1Cje mice. The 33 trisomic genes in Ts1Rhr represent a “DS critical region” that was once predicted to be sufficient to produce most DS phenotypes. We discovered significant alterations in an open field test, a novel object recognition test and in a T-maze task. As in Ts65Dn and Ts1Cje mice, LTP in FD of Ts1Rhr could be induced only after blocking GABAA-dependent inhibitory neurotransmission. In addition, widespread enlargement of dendritic spines and decreased density of spines in FD were preserved in Ts1Rhr. Twenty of 48 phenotypes showed significant differences between Ts1Rhr and 2N controls. We conclude that important neurobiological phenotypes characteristic of DS are conserved in Ts1Rhr mice. The data support the view that biologically significant trisomic phenotypes occur because of dosage effects of genes in the Ts1Rhr trisomic segment and that increased dosage is sufficient to produce these changes. The stage is now set for studies to decipher the gene(s) that play a conspicuous role in creating these phenotypes.
Central V4 Receptive Fields Are Scaled by the V1 Cortical Magnification and Correspond to a Constant-Sized Sampling of the V1 Surface
Authors: Motter Brad C.
Published: May 2009

The mapping of the topographic representation of the visual field onto cortical areas changes throughout the hierarchy of cortical visual areas. The changes are believed to reflect the establishment of modules with different spatial processing emphasis. The receptive fields (RFs) of neurons within these modules, however, may not be governed by the same spatial topographic map parameters. Here it is shown that the RFs of area V4 neurons (centered 1–12° in eccentricity) are based on a circularly symmetric sampling of the primary visual cortical retinotopic map. No eccentricity dependent magnification beyond that observed in V1 is apparent in the V4 neurons. The size and shape of V4 RFs can be explained by a simple, constant sized, two-dimensional Gaussian sample of visual input from the retinotopic map laid out across the surface of V1. Inferences about the spatial scale of interactions within the receptive fields of neurons cannot be based on a visual area's apparent cortical magnification derived from topographic mapping.
Polyglandular autoimmune syndromes
Authors: Kahaly George J
Published: May 2009

The polyglandular autoimmune syndromes (PAS) comprise a wide spectrum of autoimmune disorders and are divided into a very rare juvenile (PAS type I) and a relatively common adult type with (PAS II) or without adrenal failure (PAS III). First clinical manifestation of PAS I usually occurs in childhood, whereas PAS II mostly occurs during the third and fourth decades. PAS I is caused by mutations in the autoimmune regulatory (AIRE) gene on chromosome 21 and is inherited in an autosomal recessive manner. Mutations in the AIRE gene result in defect proteins which cause autoimmune destruction of target organs by disturbing the immunological tolerance of the patients. Genetic testing may identify patients with PAS I, but not those with PAS II/III. For PAS II/III, susceptibility genes are known which increase the risk for developing autoimmune disorders, but must not be causative. These are certain HLA genes, the cytotoxic T lymphocyte antigen gene, and the protein tyrosine phosphatase non-receptor type 22 gene on chromosomes 6, 2 and 1 respectively. Actual diagnosis of PAS involves serological measurement of organ-specific autoantibodies and subsequent functional testing. Management of patients with PAS including their family relatives is best performed in centres with special expertise in autoimmune endocrine disorders.
Transcriptional profiling enables molecular classification of adrenocortical tumours
Authors: Laurell Cecilia , Velázquez-Fernández David , Lindsten Kristina , Juhlin Christofer , Enberg Ulla , Geli Janos , Höög Anders , Kjellman Magnus , Lundeberg Joakim , Hamberger Bertil , Larsson Catharina , Nilsson Peter , Bäckdahl Martin
Published: May 2009

Objective

Tumours in the adrenocortex are common human tumours. Malignancy is however, rare, the yearly incidence being 0.5–2 per million inhabitants, but associated with a very aggressive behaviour. Adrenocortical tumours are often associated with altered hormone production with a variety of clinical symptoms. The aggressiveness of carcinomas together with the high frequency of adenomas calls for a deeper understanding of the underlying biological mechanisms and an improvement of the diagnostic possibilities.

Methods

Microarray gene expression analysis was performed in tumours of adrenocortex with emphasis on malignancy as well as hormonal activity. The sample set consisted of 17 adenomas, 11 carcinomas and 4 histological normal adrenocortexes. RNA from these was hybridised according to a reference design on microarrays harbouring 29 760 human cDNA clones. Confirmation was performed with quantitative real time-PCR and western blot analysis.

Results

Unsupervised clustering to reveal relationships between samples based on the entire gene expression profile resulted in two subclusters; carcinomas and non-cancer specimens. A large number of genes were accordingly found to be differentially expressed comparing carcinomas to adenomas. Among these were IGF2, FGFR1 and FGFR4 in growth factor signalling the most predominant and also the USP4, UBE2C and UFD1L in the ubiquitin-proteasome pathway. Moreover, two subgroups of carcinomas were identified with different survival outcome, suggesting that survival prediction can be made on the basis of gene expression profiles. Regarding adenomas with aldosterone overproduction, OSBP and VEGFB were among the most up-regulated genes compared with the other samples.

Conclusions

Adrenocortical carcinomas are associated with a distinct molecular signature apparent in their gene expression profiles. Differentially expressed genes were identified associated with malignancy, survival as well as hormonal activity providing a resource of candidate genes for an exploration of possible drug targets and diagnostic and prognostic markers.
Phenotyping and genetic studies of 357 consecutive patients presenting with premature ovarian failure
Authors: Bachelot Anne , Rouxel Agnès , Massin Nathalie , Dulon Jérome , Courtillot Carine , Matuchansky Christine , Badachi Yasmina , Fortin Anne , Paniel Bernard , Lecuru Fabrice , Lefrère-Belda Marie-Aude , Constancis Elisabeth , Thibault Elisabeth , Meduri Géri , Guiochon-Mantel Anne , Misrahi Micheline , Kuttenn Frédérique , Touraine Philippe , _ _
Published: May 2009

Objective

Premature ovarian failure (POF) encompasses a heterogeneous spectrum of conditions, with phenotypic variability among patients. The etiology of POF remains unknown in most cases. We performed a global phenotyping of POF women with the aim of better orienting attempts at an etiological diagnosis.

Design and methods

We performed a mixed retrospective and prospective study of clinical, biological, histological, morphological, and genetic data relating to 357 consecutive POF patients between 1997 and 2008. The study was conducted at a reproductive endocrinology referral center.

Results

Seventy-six percent of the patients presented with normal puberty and secondary amenorrhea. Family history was present in 14% of the patients, clinical and/or biological autoimmunity in 14.3%. Fifty-six women had a fluctuating form of POF. The presence of follicles was suggested at ultrasonography in 50% of the patients, and observed in 29% at histology; the negative predictive value of the presence of follicles at ultrasonography was 77%. Bone mineral density alterations were found in 58% of the women. Eight patients had X chromosomal abnormalities other than Turner's syndrome, eight other patients evidenced FMR1 pre-mutation. Two other patients had autoimmune polyendocrine syndrome type 2 and 1.

Conclusion

A genetic cause of POF was identified in 25 patients, i.e. 7% of the whole cohort. POF etiology remains most often undiscovered. Novel strategies of POF phenotyping are in such content mandatory to improve the rate of POF patients for whom etiology is identified.
Binary Trait Mapping in Experimental Crosses With Selective Genotyping
Authors: Manichaikul Ani , Broman Karl W
Published: May 2009

Selective genotyping is an efficient strategy for mapping quantitative trait loci. For binary traits, where there are only two distinct phenotypic values (e.g., affected/unaffected or present/absent), one may consider selective genotyping of affected individuals, while genotyping none or only some of the unaffecteds. If selective genotyping of this sort is employed, the usual method for binary trait mapping, which considers phenotypes conditional on genotypes, cannot be used. We present an alternative approach, instead considering genotypes conditional on phenotypes, and compare this to the more standard method of analysis, both analytically and by example. For studies of rare binary phenotypes, we recommend performing an initial genome scan with all affected individuals and an equal number of unaffecteds, followed by genotyping the full cross in genomic regions of interest to confirm results from the initial screen.
ThensdCGene Encoding a Putative C2H2-Type Transcription Factor Is a Key Activator of Sexual Development inAspergillus nidulans
Authors: Kim Hye-Ryun , Chae Keon-Sang , Han Kap-Hoon , Han Dong-Min
Published: May 2009

The formation of the Aspergillus nidulans fruiting body is affected by a number of genetic and environmental factors. Here, the nsdC (never in sexual development) gene—encoding a putative transcription factor carrying a novel type of zinc-finger DNA-binding domain consisting of two C2H2's and a C2HC motif that are highly conserved in most fungi but not in plants or animals—was investigated. Two distinct transcripts of 2.6 and 3.0 kb were generated from nsdC. The 2.6-kb mRNA accumulated differentially in various stages of growth and development, while the level of the 3.0-kb mRNA remained relatively constant throughout the life cycle. While the deletion of nsdC resulted in the complete loss of fruiting body formation under all conditions favoring sexual development, overexpression of nsdC not only enhanced formation of fruiting bodies (cleistothecia) but also overcame inhibitory effects of certain stresses on cleistothecial development, implying that NsdC is a key positive regulator of sexual development. Deletion of nsdC also retarded vegetative growth and hyperactive asexual sporulation, suggesting that NsdC is necessary not only for sexual development but also for regulating asexual sporulation negatively. Overexpression of veA or nsdD does not rescue the failure of fruiting body formation caused by nsdC deletion. Furthermore, nsdC expression is not affected by either VeA or NsdD, and vice versa, indicating that NsdC regulates sexual development independently of VeA or NsdD.
The Pathophysiology of Respiratory Impairment in Pediatric Neuromuscular Diseases
Authors: Panitch Howard B.
Published: May 2009

This is a summary of the presentation on the pathophysiology of respiratory impairment in pediatric neuromuscular disorders presented as part of the program on pulmonary management of pediatric patients with neuromuscular disease at the 30th annual Carrell-Krusen Neuromuscular Symposium on February 20, 2008.
The American College of Chest Physicians Consensus Statement on the Respiratory and Related Management of Patients With Duchenne Muscular Dystrophy Undergoing Anesthesia or Sedation
Authors: Birnkrant David J.
Published: May 2009

This is a summary of the presentation on the American College of Chest Physicians consensus statement on the respiratory and related management of patients with Duchenne muscular dystrophy undergoing sedation or anesthesia, presented as part of the program on pulmonary management of pediatric patients with neuromuscular disorders at the 30th Annual Carrell-Krusen Neuromuscular Symposium on February 20, 2008.
Special Considerations in the Respiratory Management of Spinal Muscular Atrophy
Authors: Schroth Mary K.
Published: May 2009

This is a summary of the presentation on special considerations in the respiratory management of spinal muscular atrophy, presented as part of the program on pulmonary management of patients with pediatric neuromuscular disorders at the 30th annual Carrell-Krusen Neuromuscular Symposium on February 20, 2008.
Oye, ¿qué onda con mi dinero?
Authors: Pinto Derrin , Raschio Richard
Published: May 2009

The objective of this study is to broaden the focus of pragmatic research to include the speech act of complaints produced by heritage speakers of Spanish. In addition to being a face-threatening act, the diverse ways in which complaints are expressed makes them a rich source for investigating how language use can vary across speech communities. Although there has been some research concerning contexts of intercultural communication, the pragmatic proficiency of heritage speakers of Spanish in the United States is an area that merits further investigation. In order to examine heritage speaker complaints, this study compares data from the following three groups: Mexican native speakers of Spanish (22), native speakers of English (40), and heritage speakers of Spanish (21). The heritage speakers and English native speakers in this study were undergraduate students at a large public university in California, while the native speakers of Spanish were university students in Mexico. All the participants completed an on-line Discourse Completion Test that included three complaint scenarios.
Changing trends in language choice in Nigeria
Authors: Igboanusi Herbert
Published: May 2009

With over 250 ethnic nationalities and about 400 indigenous languages (Adegbija 1997) existing alongside English (the official language) and Nigerian Pidgin (NP), it is to be expected that language choice in Nigeria will be complex. Patterns of choices in language are not static and may be caused to change from time to time by socio-political developments within a society. The present study examines the extent to which socio-political activities, ethnic reawakening, state creation, migration and economic considerations may affect drift in language use. It identifies changing trends in language choice in the legislature, the print media, in political campaigns, in writing, among young persons, for ethnic disidentity, and choices induced by regional retraction and the rise of ‘state languages’. While some changes indicate an expanding use of the indigenous languages (as with the cases of the legislature, political campaign, the print media, writing and the rise of ‘state languages’), trends in language of the youth and language use in the electronic media point to a growing dominance of English.
Multilingualism in European bilingual contexts: Language use and attitudes. David Lasagabaster and Ángel Huguet (eds) (2007)
Authors: Aronin Larissa
Published: May 2009

Multilingualism in European bilingual contexts: Language use and attitudes. David Lasagabaster and Ángel Huguet (eds) (2007)Clevedon: Multilingual Matters. pp. 251. ISBN 1–85359–930–1/ EAN 978–1-85359–930–9 (hbk) ISBN 1–85359–929–8/ EAN 978–1-85359–929–3 (pbk)
The monolingual mindset as an impediment to the development of plurilingual potential in Australia
Authors: Clyne Michael
Published: May 2009

This article shows how the monolingual mindset of many decision makers in fields such as education detracts from Australia’s capacity to develop its potential in plurilingualism. It contrasts the projection of monolingualism as the desired norm with the linguistic diversity within the Australian community. A number of fallacious clichés are discussed critically and attributed to the monolingual mindset – the overcrowded curriculum, competing literacies, the ‘unfair advantage’ of students with a home background in a language which they are studying, and the sufficiency of global English. It is suggested that more plurilinguals are needed in decision making roles.