bluuebunny/crossref_metadata_2025 huggingface dataset:
Recruitment of cdk9 to the Immediate-Early Viral Transcriptosomes during Human Cytomegalovirus Infection Requires Efficient Binding to Cyclin T1, a Threshold Level of IE2 86, and Active Transcription
Authors: Kapasi Anokhi J. , Clark Charles L. , Tran Karen , Spector Deborah H.
Published: March 2009

Human cytomegalovirus (HCMV) infection results in the formation of nuclear viral transcriptosomes, which are sites dedicated to viral immediate-early (IE) transcription. At IE times of the infection, viral and cellular factors, including several components of transcription such as cyclin-dependent kinase 9 (cdk9), localize at these sites. To determine the mechanism and requirements of specific recruitment of cdk9 to the viral transcriptosomes, infection in the presence of inhibitor drugs and infection of cell lines expressing exogenous mutant cdk9 were performed. We found that cdk9 localization to the viral transcriptosomes requires de novo protein synthesis. In addition, active transcription is required for recruitment and maintenance of cdk9 at the viral transcriptosomes. In cells infected with a recombinant IE2 HCMV (IE2 86 ΔSX virus) in which IE2 gene expression is greatly reduced, cdk9 localization at the transcriptosome is delayed and corresponds to the kinetics of accumulation of the IE2 protein at these sites. Infection in the presence of the cdk9 inhibitors Flavopiridol and DRB (5,6-dichloro-1-β-
d
-ribofuranosylbenzimidazole) allowed cdk9 localization to the viral transcriptosomes. A kinase-inactive cdk9 (D167N) expressed during the infection also localizes to the viral transcriptosomes, indicating that kinase activity of cdk9 is not a requirement for its localization to the sites of IE transcription. Exogenous expression of additional cdk9 mutants indicates that binding of Brd4 to the cdk9 complex is not required but that efficient binding to cyclin T1 is essential.
Evaluation of the influence of boundary confinement on the behaviour of unsaturated swelling clay soils
Authors: Siemens Greg , Blatz James A.
Published: March 2009

Swelling soils are found in many regions throughout the world. Damage caused to infrastructure by these types of soils is measured annually in billions of dollars. These excessive damages are, in part, due to the lack of proper design, resulting from a need for better tools for practitioners to assess the impact of swelling soils in typical design applications. This paper presents an experimental testing program with interpretations to provide a framework for predicting the behaviour of swelling soils under general stress and volume state conditions for practical applications. The experimental testing adopted a new automated triaxial apparatus that controls boundary stress and strain while applying liquid infiltration conditions at the perimeter or center of triaxial specimens. Results demonstrate the influence of a range of boundary conditions on the behaviour of swelling soil during liquid infiltration. The range of boundary conditions examined in the experimental testing include constant mean stress (CMS), where the mean stress applied during the swelling stage is constant; constant volume (CV), where the volume is held constant during the liquid infiltration; as well as a flexible spring-type boundary condition (CS) that applies increases in stress as a specified function of the volume increase. These boundary conditions represent the broad spectrum of experiences in the field. The experimental results show the dominance of boundary conditions on the development of swell pressure and volume expansion to give evidence for a new swell equilibrium limit (SEL) relationship. The SEL shows promise in providing a framework for swelling soils to predict the final soil state under wetting conditions for the range of boundary conditions examined. Application of the SEL relationship in practice is presented as a concept for examining swelling induced pressures and volume expansion in applications of liquid infiltration of swelling soils.
Full-scale testing of draped nets for rock fall protection
Authors: Bertolo Paola , Oggeri Claudio , Peila Daniele
Published: March 2009

The installation of draped meshes, metallic nets installed in such a way as to lie against the rock slope surface, is one of the most common ways to protect roads and infrastructure against the detachment of small rock elements in areas prone to rock fall. Despite their frequent and worldwide application, there are no universally recognized guidelines or technical standards to help engineers in their correct design, and no full-scale test results are available where the whole system, composed of several interacting structural components, is tested. In this paper, a full-scale test procedure, which is able to permit the evaluation of the global behaviour of a draped mesh, is described and the results of tests carried out on widely used meshes are presented and discussed.
Motors, Switches, and Contacts in the Replisome
Authors: Hamdan Samir M. , Richardson Charles C.
Published: March 2009

Replisomes are the protein assemblies that replicate DNA. They function as molecular motors to catalyze template-mediated polymerization of nucleotides, unwinding of DNA, the synthesis of RNA primers, and the assembly of proteins on DNA. The replisome of bacteriophage T7 contains a minimum of proteins, thus facilitating its study. This review describes the molecular motors and coordination of their activities, with emphasis on the T7 replisome. Nucleotide selection, movement of the polymerase, binding of the processivity factor, unwinding of DNA, and RNA primer synthesis all require conformational changes and protein contacts. Lagging-strand synthesis is mediated via a replication loop whose formation and resolution is dictated by switches to yield Okazaki fragments of discrete size. Both strands are synthesized at identical rates, controlled by a molecular brake that halts leading-strand synthesis during primer synthesis. The helicase serves as a reservoir for polymerases that can initiate DNA synthesis at the replication fork. We comment on the differences in other systems where applicable.
Mitogen-activated protein kinase signaling is necessary for the maintenance of skeletal muscle mass
Authors: Shi Hao , Scheffler Jason M. , Zeng Caiyun , Pleitner Jonathan M. , Hannon Kevin M. , Grant Alan L. , Gerrard David E.
Published: March 2009

The signal transduction cascades that maintain muscle mass remain to be fully defined. Herein, we report that inhibition of extracellular signal-regulated kinase 1/2 (ERK1/2) signaling in vitro decreases myotube size and protein content after 3-day treatment with a MEK inhibitor. Neither p38 nor JNK inhibitors had any effect on myotube size or morphology. ERK1/2 inhibition also upregulated gene transcription of atrogin-1 and muscle-specific RING finger protein 1 and downregulated the phosphorylation of Akt and its downstream kinases. Forced expression of enhanced green fluorescent protein-tagged MAPK phosphatase 1 (MKP-1) in soleus and gastrocnemius muscles decreased both fiber size and reporter activity. This atrophic effect of MKP-1 was time dependent. Analysis of the reporter activity in vivo revealed that the activities of nuclear factor-κB and 26S proteasome were differentially activated in slow and fast muscles, suggesting muscle type-specific mechanisms may be utilized. Together, these findings suggest that MAPK signaling is necessary for the maintenance of skeletal muscle mass because inhibition of these signaling cascades elicits muscle atrophy in vitro and in vivo.
CapZ dynamics are altered by endothelin-1 and phenylephrine via PIP2- and PKC-dependent mechanisms
Authors: Hartman Thomas J. , Martin Jody L. , Solaro R. John , Samarel Allen M. , Russell Brenda
Published: March 2009

One of the unanswered questions in muscle hypertrophy is how new contractile units are inserted into a stable existing cytoskeletal meshwork. Regulation of actin capping by CapZ may play a role in remodeling processes, therefore, CapZ dynamics are determined during rapid growth of cardiac cells in vitro. Neonatal rat ventricular myocytes were infected with adenovirus expressing green fluorescent protein-CapZ β1 and responded normally to hypertrophic stimuli. CapZ dynamics were analyzed by fluorescence recovery after photobleaching in cultured myocytes treated with endothelin-1 (100 nM) or phenylephrine (10 μM). Recovery by 30 s was greater with endothelin treatment. Analysis 30 min postbleach showed CapZ-infected cells treated with endothelin recovered more completely than controls (77 ± 9% vs. 50 ± 6%, P < 0.001). Similar results were found with phenylephrine (77 ± 5%, P < 0.05). A potential mechanism for phosphatidylinositol bisphosphate (PIP2) mediation of increased CapZ exchange in endothelin- and phenylephrine-treated cells was tested. PIP2 sequestration with neomycin (500 μM) blocked both endothelin- (43 ± 6%, P < 0.001) and phenylephrine (36 ± 4%, P < 0.001)-mediated recovery. The protein kinase C inhibitor chelerythrine chloride (10 μM) also blocked endothelin- (53 ± 10%, P < 0.001) and phenylephrine (42 ± 3%, P < 0.001)-mediated recovery. This study demonstrates for the first time that endothelin and phenylephrine alter CapZ dynamics through PIP2- and PKC-dependent pathways, which might destabilize the existing framework and permit sarcomeric remodelling to proceed.
Inhibition of Kv1.3 potassium current by phosphoinositides and stromal-derived factor-1α in Jurkat T cells
Authors: Matsushita Yuichiro , Ohya Susumu , Suzuki Yoshiaki , Itoda Haruna , Kimura Takuya , Yamamura Hisao , Imaizumi Yuji
Published: March 2009

The activation of Kv1.3 potassium channel has obligatory roles in immune responses of T lymphocytes. Stromal cell-derived factor-1α (SDF-1α) binds to C-X-C chemokine receptor type 4, activates phosphoinositide 3-kinase, and plays essential roles in cell migration of T lymphocytes. In this study, the effects of phosphoinositides and SDF-1α on Kv1.3 current activity were examined in the Jurkat T cell line using whole cell patch-clamp techniques. The internal application of 10 μM phosphatidylinositol 4,5-bisphosphate (PIP2) or 10 μM phosphatidylinositol-3,4,5-trisphosphate (PIP3) significantly reduced Kv1.3 current, but that of 10 μM phosphatidylinositol-4-monophosphate (PIP) did not. The coapplication of 10 μg/ml anti-PIP3 antibody with PIP2 from the pipette did not change the reduction of Kv1.3 current by PIP2, but the coapplication of the antibody with PIP3 eliminated the reduction. The heat-inactivated anti-PIP3 antibody had no effect on PIP3-induced inhibition. These results suggest that PIP2 per se can reduce Kv1.3 current as well as PIP3. External application of 1 μM Akt-kinase inhibitor VIII did not reverse the effect of intracellular PIP3. External application of 10 and 30 ng/ml SDF-1α significantly reduced Kv1.3 current. Internal application of anti-PIP3 antibody reversed the SDF-1α-induced reduction. These results suggest that, in Jurkat T cells, PIP2, PIP3, and SDF-1α reduce Kv1.3 channel activity and that the reduction by SDF-1α may be mediated by the enhancement of PIP3 production. These novel inhibitory effects of phosphoinositides and SDF-1α on Kv1.3 current may have a significant function as a downregulation mechanism of Kv1.3 activity for the maintenance of T lymphocyte activation in immune responses.
Quantum Barnes Function as the Partition Functionof the Resolved Conifold
Authors: Koshkin Sergiy
Published: March 2009

We give a short new proof of large N duality between the Chern‐Simons invariants
of the 3‐sphere and the Gromov‐Witten/Donaldson‐Thomas invariants of
the resolved conifold. Our strategy applies to more general situations, and it is
to interpret the Gromov‐Witten, the Donaldson‐Thomas, and the Chern‐Simons
invariants as different characterizations of the same holomorphic function. For the
resolved conifold, this function turns out to be the quantum Barnes function, a
natural q‐deformation of the classical one that in its turn generalizes the Euler
gamma function. Our reasoning is based on a new formula for this function that
expresses it as a graded product of q‐shifted multifactorials.
Near-Surface Temperature Lapse Rates over Arctic Glaciers and Their Implications for Temperature Downscaling
Authors: Gardner Alex S. , Sharp Martin J. , Koerner Roy M. , Labine Claude , Boon Sarah , Marshall Shawn J. , Burgess David O. , Lewis David
Published: March 2009

Distributed glacier surface melt models are often forced using air temperature fields that are either downscaled from climate models or reanalysis, or extrapolated from station measurements. Typically, the downscaling and/or extrapolation are performed using a constant temperature lapse rate, which is often taken to be the free-air moist adiabatic lapse rate (MALR: 6°–7°C km−1). To explore the validity of this approach, the authors examined altitudinal gradients in daily mean air temperature along six transects across four glaciers in the Canadian high Arctic. The dataset includes over 58 000 daily averaged temperature measurements from 69 sensors covering the period 1988–2007. Temperature lapse rates near glacier surfaces vary on both daily and seasonal time scales, are consistently lower than the MALR (ablation season mean: 4.9°C km−1), and exhibit strong regional covariance. A significant fraction of the daily variability in lapse rates is associated with changes in free-atmospheric temperatures (higher temperatures = lower lapse rates). The temperature fields generated by downscaling point location summit elevation temperatures to the glacier surface using temporally variable lapse rates are a substantial improvement over those generated using the static MALR. These findings suggest that lower near-surface temperature lapse rates can be expected under a warming climate and that the air temperature near the glacier surface is less sensitive to changes in the temperature of the free atmosphere than is generally assumed.
Decadal Fluctuations in Planetary Wave Forcing Modulate Global Warming in Late Boreal Winter
Authors: Cohen Judah , Barlow Mathew , Saito Kazuyuki
Published: March 2009

The warming trend in global surface temperatures over the last 40 yr is clear and consistent with anthropogenic increases in greenhouse gases. Over the last 2 decades, this trend appears to have accelerated. In contrast to this general behavior, however, here it is shown that trends during the boreal cold months in the recent period have developed a marked asymmetry between early winter and late winter for the Northern Hemisphere, with vigorous warming in October–December followed by a reversal to a neutral/cold trend in January–March. This observed asymmetry in the cold half of the boreal year is linked to a two-way stratosphere–troposphere interaction, which is strongest in the Northern Hemisphere during late winter and is related to variability in Eurasian land surface conditions during autumn. This link has been demonstrated for year-to-year variability and used to improve seasonal time-scale winter forecasts; here, this coupling is shown to strongly modulate the warming trend, with implications for decadal-scale temperature projections.
Understanding the Regional Variability of Eddy Diffusivity in the Pacific Sector of the Southern Ocean
Authors: Shuckburgh Emily , Jones Helen , Marshall John , Hill Chris
Published: March 2009

A diagnostic framework is presented, based on the Nakamura effective diffusivity, to investigate the regional variation in eddy diffusivity. Comparison of three different diffusivity calculations enables the effects of locally enhanced tracer diffusion to be distinguished from the streamwise average. It also enables the distinction to be made between locally generated complexity in the tracer structure and that advected into a particular domain. The technique is applied to the Pacific sector of the Southern Ocean. The results highlight the important role that the mean flow plays in determining eddy diffusivity. The effective diffusivity is not simply related to the eddy kinetic energy: in regions of a strong mean flow the eddy diffusivity can be suppressed even in the presence of moderately strong eddy activity; conversely, in a region of weak mean flow the eddy diffusivity can be enhanced even in the presence of only weak eddy activity. This casts doubt on the ability of parameterizations based solely on the eddy kinetic energy to adequately characterize the eddy diffusivity in regions of strongly varying mean flow such as the Southern Ocean. The results are, however, consistent with the eddy transport and mixing variability predicted by potential-vorticity-based arguments.
A Comparison of Meteorological Observations from South Pole Station before and after Installation of a New Instrument Suite
Authors: Keller L. M. , Baker K. A. , Lazzara M. A. , Gallagher J.
Published: March 2009

The Amundsen–Scott South Pole surface meteorological instrument suite was upgraded in 2004. To ensure that the new and old instruments were recording similar information, the two suites of instruments ran simultaneously for a year. Statistical analysis of the time series of temperature, pressure, and wind was performed to determine if there were any significant differences in the observations. Significant differences were found in some of the winter months for temperature and wind speed. No differences were found for the wind direction distribution. There are also noticeable differences in wind speed between the Clean Air platform near the Clean Air facility and the platform at the approach end of the skiway. Wind speeds are lower at the skiway tower when the wind is from the northeast quadrant and at the Clean Air tower when the wind is from the southwest quadrant, reflecting the effect of increased surface roughness and flow distortion over and around the station structures. Because of a change in elevation of the pressure sensor, the pressure data were recalculated at a common station elevation (2836 m). Although the resulting differences are small (around 0.1 hPa), there is a systematic sign change between summer and winter. The results of this analysis, while revealing some significant differences, show that the new instrumentation at South Pole station is generally reporting observations that are similar to those of the old instrumentation, and most of the differences are within the accuracy of the instruments. However, the instrument placement and construction of official aviation routine weather reports (METARs) do have an impact on the usefulness of the data for research.
An Evaluation of χT Estimation Techniques: Implications for Batchelor Fitting and ɛ
Authors: Steinbuck Jonah V. , Stacey Mark T. , Monismith Stephen G.
Published: March 2009

Techniques for the accurate estimation of the dissipation rate of temperature variance χT from temperature microstructure measurements are synthesized and evaluated. The techniques focus on the treatment of contamination in the integration of the vertical temperature gradient spectrum. The essential improvements come from estimating χT from the wavenumber domain in which the signal exceeds the noise and from reconstructing unresolved wavenumber contributions using the best-fit Batchelor spectrum. The improvement in the estimates of χT results in better Batchelor fits and more robust estimates of the dissipation rate of turbulent kinetic energy ɛ. High correlations of independent measurements of χT and ɛ from two collocated FP07 thermistors demonstrate the value of the techniques and highlight the improvements at the low end of the resolvable ranges of χT and ɛ.
The PHA Depolymerase Engineering Database: A systematic analysis tool for the diverse family of polyhydroxyalkanoate (PHA) depolymerases
Authors: Knoll Michael , Hamm Thomas M , Wagner Florian , Martinez Virginia , Pleiss Jürgen
Published: March 2009

Background

Polyhydroxyalkanoates (PHAs) can be degraded by many microorganisms using intra- or extracellular PHA depolymerases. PHA depolymerases are very diverse in sequence and substrate specificity, but share a common α/β-hydrolase fold and a catalytic triad, which is also found in other α/β-hydrolases.

Results

The PHA Depolymerase Engineering Database (DED, http://www.ded.uni-stuttgart.de) has been established as a tool for systematic analysis of this enzyme family. The DED contains sequence entries of 587 PHA depolymerases, which were assigned to 8 superfamilies and 38 homologous families based on their sequence similarity. For each family, multiple sequence alignments and profile hidden Markov models are provided, and functionally relevant residues are annotated.

Conclusion

The DED is a valuable tool which can be applied to identify new PHA depolymerase sequences from complete genomes in silico, to classify PHA depolymerases, to predict their biochemical properties, and to design enzyme variants with improved properties.
Age and gender specific normal values of left ventricular mass, volume and function for gradient echo magnetic resonance imaging: a cross sectional study
Authors: Cain Peter A , Ahl Ragnhild , Hedstrom Erik , Ugander Martin , Allansdotter-Johnsson Ase , Friberg Peter , Arheden Hakan
Published: March 2009

Background

Knowledge about age-specific normal values for left ventricular mass (LVM), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) by cardiac magnetic resonance imaging (CMR) is of importance to differentiate between health and disease and to assess the severity of disease. The aims of the study were to determine age and gender specific normal reference values and to explore the normal physiological variation of these parameters from adolescence to late adulthood, in a cross sectional study.

Methods

Gradient echo CMR was performed at 1.5 T in 96 healthy volunteers (11–81 years, 50 male). Gender-specific analysis of parameters was undertaken in both absolute values and adjusted for body surface area (BSA).

Results

Age and gender specific normal ranges for LV volumes, mass and function are presented from the second through the eighth decade of life. LVM, ESV and EDV rose during adolescence and declined in adulthood. SV and EF decreased with age. Compared to adult females, adult males had higher BSA-adjusted values of EDV (p = 0.006) and ESV (p < 0.001), similar SV (p = 0.51) and lower EF (p = 0.014). No gender differences were seen in the youngest, 11–15 year, age range.

Conclusion

LV volumes, mass and function vary over a broad age range in healthy individuals. LV volumes and mass both rise in adolescence and decline with age. EF showed a rapid decline in adolescence compared to changes throughout adulthood. These findings demonstrate the need for age and gender specific normal ranges for clinical use.
Quantitative Analysis of Human Kallikrein 5 (KLK5) Expression in Prostate Needle Biopsies: An Independent Cancer Biomarker
Authors: Korbakis Dimitrios , Gregorakis Alkiviades K , Scorilas Andreas
Published: March 2009

Background: Kallikrein 5 (KLK5), a recently cloned member of the kallikrein family, codes for the secreted protein KLK5. Active KLK5 protein has a trypsin activity, and the expression of KLK5 gene seems to be regulated by steroid hormones. We performed an expression analysis and clinical evaluation of the KLK5 gene, at the mRNA level, in prostate needle biopsies.

Methods: We examined KLK5 mRNA concentrations in 103 prostate tissue specimens. After testing of RNA quality, cDNA was prepared by reverse transcription. A highly sensitive quantitative real-time PCR (qRT-PCR) method for KLK5 mRNA quantification was developed using the SYBR Green chemistry. GAPDH was used as a housekeeping gene.

Results: Specimens from patients with benign prostatic hyperplasia (BPH) showed higher levels of KLK5 mRNA expression than those from patients with prostate cancer (PCa) (P = 0.024). ROC analysis demonstrated that KLK5 expression had significant discriminatory value between BPH and PCa (AUC 0.64; P = 0.016). KLK5 mRNA expression showed a statistically significant negative correlation with the total PSA serum concentration in the PCa patients (P = 0.003). Early-stage tumors showed higher KLK5 expression than late-stage ones (P = 0.014), whereas KLK5 expression was negatively correlated to Gleason score (P = 0.005).

Conclusions: KLK5 mRNA, analyzed by quantitative PCR in prostate needle biopsies, could be an independent biomarker for the differential diagnosis and prognosis in prostate cancer.
A Numerical Study of Non-Steady-State Creep at Stationary Crack Tips
Authors: Leung C-P , McDowell DL , Saxena A
Published: March 2009

A finite-element creep analysis of a center-crack specimen was carried out under small-scale to extensive creep conditions. The crack was assumed to be stationary. Two constitutive models were used, one consisting of elastic-power-law creep and the other of elastic-power-law creep plus rate-independent power-law strain hardening. The mechanics basis of the Ct parameters, which has been proposed for correlating creep crack growth behavior under conditions ranging from small-scale to extensive creep, is explored. Also, an earlier discrepancy in this test specimen between analytically predicted deflection rates and experimental results is investigated. The authors conclude that in small-scale creep, Ct does not characterize the instantaneous crack-tip singular stress field, but accurately reflects the compliance change due to the development of the creep zone around the crack tip. The experimental results, which show higher displacement rates than predicted, cannot be explained by inclusion of time- and rate-independent plasticity but may possibly be due to primary creep.
Crack Growth in Small-Scale Creep
Authors: Bassani JL , Hawk DE , Wu F-H
Published: March 2009

Transient crack growth in an elastic/power-law creeping material is investigated under plane-strain Mode I loading and small-scale-creep conditions. At time t = 0, the solid with a semiinfinite crack is suddenly loaded by tractions corresponding to the elastic crack-tip stress distribution. Both constant and variable crack-tip velocities are considered. In the variable velocity case, the crack propagates based on a critical strain criterion. The stress fields evolve in a complex manner as the crack propagates because of competing effects of stress relaxation, due to constrained creep, and stress elevation, due to the instantaneous elastic material response to crack growth. In both cases, detailed finite-element calculations show that the stress field can be approximated by a matching of three asymptotic singular crack-tip solutions. Also, the predicted crack growth histories from a one-dimensional damage model coupled with this matching are summarized.
Experimental Determination of the High-Temperature Crack Growth Behavior of Incoloy 800H
Authors: Hollstein T , Voss B
Published: March 2009

Crack growth and the crack growth rate can be determined continuously by using the single-specimen partial unloading compliance technique, modified for high-temperature tests, or a direct-current potential drop technique with similar accuracy for temperatures up to 800C and test durations from a few hours up to several months. The possibilities and limitations of the experimental setup are discussed.

The increasing influence of time-dependent processes with increasing test temperature is shown on the basis of J-integral versus crack growth resistance curves (J-R curves), determined in short-time tests in the temperature range from room temperature to 800C. Creep deformation and creep crack growth are significant for this alloy at temperatures higher than about 600C.

An evaluation in terms of J-R curves represents the limiting case of negligible time-dependent effects, and therefore it is only meaningful for relatively high loading with relatively high deformation rates. This is demonstrated for high-temperature crack growth experiments with different loading rates. For these cases the evaluation of the short-time tests (less than one day) in terms of the C*-integral for steady-state creep conditions is consistent with results of long-time creep tests at 800C.
Combined-Mode Low-Cycle Fatigue Crack Growth Under Torsional Loading
Authors: Williams RA , Wilkening WW
Published: March 2009

Faults or other disturbances in an electrical distribution system can potentially feed back to the turbine-generator and produce large-amplitude torsional oscillations in the turbine-generator shaft. These transient torques, in combination with gravity-induced and misalignment-induced bending stresses in the shaft, can give rise to significant combined-mode fatigue crack growth phenomena. Prediction of the fatigue damage or of the growth rate of existing flaws under these complex loading conditions has been the subject of numerous investigations in the past. The work described here focuses upon the development of a correlation of the experimentally measured combined-mode fatigue crack growth rate (FCGR) with a suitable fracture mechanics characterizing parameter.

Since the torsional stress levels involved in transient oscillations can be comparable to the yield strength, linear elastic fracture mechanics (LEFM) parameters (for example, K, the stress-intensity factor range) are not appropriate for correlating the crack growth rate. Consequently, a set of elastic-plastic crack driving force solutions was developed for part-circumferential through cracks in a thin-walled tube. Another similar set of elastic-plastic crack driving force solutions for circumferential cracks in a solid cylinder was also developed. Elastic-plastic finite-element analysis techniques, including the virtual crack extension method, were used to develop these solutions, in terms of the energy release rate, J. The geometry and the constitutive behavior of the models mimicked that of the corresponding specimens tested in the associated experimental portion of this program.

Pure Mode II fatigue crack growth was obtained in thin-walled tubular specimens through pure torsional loading, while combined Mode I plus Mode II crack growth was obtained by superimposing in-phase tensile cycling. Similarly, Mode III fatigue crack growth was achieved via torsional loading of the solid cylindrical specimens.

The analytical and experimental results discussed here demonstrate that the measured FCGR can be correlated with the range of the energy release rate,J, computed by elastic-plastic means, or with the corresponding range of the elastic-plastic effective stress-intensity factor range, Kj(EJ). In addition, for the shaft material studied here, the FCGR relation for all combined-mode cases was found to be essentially identical to that for pure Mode I fatigue crack growth.
Chlorosulfonated Polyethylene Sealants
Authors: Painter SS
Published: March 2009

This paper discusses chlorosulfonated polyethylene (CSPE) based sealants. Covered are the chemistry, formulating and compounding, characteristics, usage, preparation, and application of these sealants.
Urethane Sealants
Authors: Evans RM , Greene RB
Published: March 2009

This paper presents a discussion of urethane sealants in three parts: commercial applications, chemistry, and specifications. In the first part, urethane sealants for use on concrete structures, glass and glazing, curtain walls, split slabs, highways, and in vehicles are discussed. The price and performance of urethanes are compared to other sealants.

The chemistry section shows how commercially desirable properties are produced by the use of various chemical functional groups.

The specification section relates test methods to commercial properties and chemical groupings.
Cold-Applied Fluid Elastomeric Waterproofing Membranes
Authors: Fogel J
Published: March 2009

The uses of cold-applied fluid elastomeric membranes for waterproofing are discussed, particularly in comparison with other means of waterproofing. The features of the available types of membranes are discussed: coal tar/polymer, asphalt/polymer, rubberized asphalt, and emulsion membranes. Finally, a series of drawings show the optimum design features for the use of these membranes, including the details of preparation for application.
A Membrane Applicator's Viewpoint
Authors: Cianciotto OJ
Published: March 2009

Tentative parameters on what constitutes a perfect membrane system are advanced. Liquid applied, seamless, elastomeric, film forming membranes are seen as meeting most of the requirements that would constitute approaching the perfect membrane system, and properties of these systems are given. The effectiveness of the liquid applied membranes is seen to be directly related to the details of construction, with suggested membrane details for maximum waterproof results. Other areas covered are the use of the liquid applied membranes as surface seals, with related components and accessories; the sealing of horizontal joints in conjunction with liquid applied membrane systems; and the sealing of building deck surfaces. This paper concludes with a definitive limit placed on manufacturers of liquid applied membrane material in the area of responsibility and valid guarantees.
Commercial Aircraft
Authors: June RR , Lager JR
Published: March 2009

The use of composite materials offers considerable potential for reducing structural weight and, therefore, increasing productivity of commercial aircraft. The application of composites must be performed selectively, as some structures offer considerable potential for cost effective use, whereas others are more cost effective as metal structures. Heavily loaded beams, columns, and stiffness critical control surfaces are at present the major areas of application of composite materials.
Space Structures
Authors: Forest JD , Christian JL
Published: March 2009

The use of fibrous composites for space structures offers considerable potential because of the high premium placed on weight saving. Space applications which are discussed in this chapter include a missile interstage adapter, pressure vessels, a truss supporting structure, a dish antenna, and a re-entry vehicle. Both epoxy matrix and aluminum matrix materials have been used for these applications and are included in the discussion.
Chapter 1—Procedures for Standard Replication Techniques for Electron Microscopy
Authors:   Task Group E04.11.02
Published: March 2009

While substantially supplemented in the last decade by thin foil transmission and scanning electron microscopy, replica electron microscopy remains a major technique in contemporary metallurgical investigations.
Chapter 3—Thin Foil Preparation for Transmission Electron Microscopy
Authors:   Task Group E04.11.03
Published: March 2009

The desire and need to observe real structures and finer detail has resulted not only in higher performance electron microscopes but also resulted in a great deal of time and effort spent to design and develop better specimen preparation techniques. Since the first direct examination of thin metal foils in 1949 by Heindenreich[I], 2 many different methods of thin film preparation have evolved. This paper will not deal with transmission image interpretation but is intended as a review of procedures and basic techniques of thin foil preparation collected from literature and includes methods contributed by different laboratories represented on the American Society for Testing and Materials (ASTM) Subcommittee E04.11 on Electron Microscopy and Diffraction. Appendix 3.2 provides a complete bibliography of papers published in ASTM Special Technical Publications pertaining to thin foil preparation and applications of transmission electron microscopy of metals.
Chapter 4—Selected Area Electron Diffraction Analysis of Extraction Replica and Thin Foil Specimens in the Transmission Electron Microscope
Authors:   Task Group E04.ll.05
Published: March 2009

This procedure is intended as a guide for satisfactory selected area electron diffraction (SAED) analysis in the transmission electron microscope (TEM), of extraction replica and thin foil specimens. It is intended to help those who have a minimal understanding of crystallography but desire to use electron diffraction analysis for identification of precipitates or determination of their orientation (or orientation of other substructural features) relative to the matrix or both. A stepwise outline form is presented of the procedures to be followed without much theoretical background; however, a list of references1–6]2 is provided to supplement this procedure with as much theory as is desired. Two examples of the application of the procedure are also given.
Rapid Biological Monitoring System for Determining Aquatic Community Structure in Receiving Systems
Authors: Cairns J , Dickson KL , Lanza G
Published: March 2009

Biological monitoring plays an important role in a pollution monitoring program providing information not available through conventional physical and chemical monitoring. The saprobic system and the use of structural and functional changes in aquatic communities are two approaches utilized in assessing the effects of pollutants on aquatic communities. The feedback of information from conventional instream biological monitoring has been too slow for the most effective management of an aquatic system. Two rapid biological monitoring systems (the Sequential Comparison Index, and an automated community structure analysis using laser holography) have been developed to increase the speed of data collection and data analysis.
Assessment of Fish Flesh Tainting Substances
Authors: Thomas NA
Published: March 2009

Increased use of lakes and rivers for sport and commercial fishing in the vicinity of large municipal and industrial discharges has led to the realization that fish in many bodies of water are not palatable. The discharge of organic compounds has led to the contamination of fish flesh to such an extent that fishing is curtailed more because of poor eating quality rather than the lack of fish.

To evaluate the magnitude of the tainting of fish flesh in a large river, studies were conducted on the flavor of channel catfish (Ictalurus punctatus Rafinesque) flesh from the Ohio River from Pittsburgh, Pa., to Cairo, Ill. Tasting of fish flesh determined that a panel could differentiate between fish held upstream and downstream from a wastewater discharge. Caged test fish exposed for three days acquired a minimum of 70 percent of the off-flavor of native fish.
Asphalt Viscosity-Related Properties of In-Service Pavements in Pennsylvania
Authors: Kandhal PS , Sandvig LD , Koehler WC , Wenger ME
Published: March 2009

Six viscosity-graded asphalts from different sources were used in the construction of the pavements studied and reported in this paper. Tests to determine the viscosity-related properties of the original asphalts, as well as the asphalts recovered from time to time from the pavements in service, have been conducted. Evaluation of the performance of these test pavements has been carried out by a team of five engineers.

The aging index based on viscosity at 77 F (25 C) has been found to conform to the pavement performance rating and thus seems to be more meaningful to indicate comparative aging and life expectancy of the test pavements. Shear susceptibility of the asphalt cements seems to be one of the major factors affecting the pavement performance. Present viscosity-graded specifications should be supplemented with a maximum permissible shear-susceptibility value at 77 F so as to control the durability of the asphalts. The maximum amount of shear susceptibility that may develop in a paving-grade asphalt prior to pavement failure is indicated in the data obtained.
Collection and Handling of Physical Evidence for a Forensic Laboratory
Authors: Buscemi PC , Washington WD
Published: March 2009

The special considerations which must be given to the collection and handling of physical evidence from the scene of a crime for a forensic laboratory are presented. Specifically covered are the handling of physical evidence from criminal acts which violate those jurisdictions comprising an important segment of the responsibilities of the Bureau of Alcohol, Tobacco and Firearms in the U.S. Treasury Department.

Many of the unique characteristics of this unusual type of sampling are discussed, particularly those aspects differing markedly from the more routine types of chemical sampling. Topics covered in detail include the following: the selection of materials of possible evidential value; the process of collecting and gathering such items of interest; the importance of marking and labeling properly; the packaging of these materials; their preservation; the proper transmission to the forensic laboratory; and the associated legal requirements which must be adhered to throughout this procedure.
Sampling and On-Stream X-Ray Control of Portland Cement Raw Mix Slurry
Authors: Moore CW , Maars CD
Published: March 2009

The trend in the cement industry toward large grinding mills, kilns, and kiln feed storage facilities has emphasized the need for continuous on-stream control of the chemical composition of the raw mix. This paper describes a sampling and control system in which the chemical composition of the solids in a continuous sample of flowing slurry is monitored by X-ray emission techniques. The chemical composition is used by a raw mill blending and control program to adjust feed rates of the raw material streams entering the raw grinding mill. A more uniform product in terms of certain chemical and physical properties of the cement has resulted from the combined performance of the X-ray sampling and control system, the kiln, and the finished cement grinding system.
Concepts and Applications of Multidimensional Scaling
Authors: Wish M , Carroll JD
Published: March 2009

Multidimensional scaling (MDS) is a general term for a class of techniques that can be used to develop spatial representations of psychological stimuli or other objects. The typical input data for these procedures is a matrix of distance-like numbers which indicate how similar or different every stimulus is to each of the others. These similarity or dissimilarity values may be based on objective measurements or subjective judgments. MDS techniques involve iterative algorithms, usually requiring high-speed computers, for constructing the spatial configuration, or “map.”

Although some mention is made of earlier MDS procedures, primary attention is given to describing and illustrating a new technique called “INDSCAL,” for INdividual Differences SCALing. The input to INDSCAL is several matrices of similarities or dissimilarities among the objects, usually one for each subject participating in a study. The output from INDSCAL includes information about the weight, or perceptual importance, of each dimension for every subject, as well as a multidimensional space for the stimulus objects. The applications illustrate the wide range of stimuli and experimental methods that can be used in studies involving MDS, and demonstrate some special advantages of INDSCAL.
Radiation-Induced Changes in the Fracture Extension Resistance (R-Curve) of Structural Steels
Authors: Hawthorne JR , Watson HE
Published: March 2009

The effects of irradiation on the fracture extension resistance of low- and medium-strength steel plates were explored using R-curve assessment procedures newly developed at the Naval Research Laboratory. The study employed four thick plates of A212-B, A302-B, A533-B, and A543-1 steel. The plates were specifically selected to depict a broad range of pre-irradiation dynamic tear (DT) upper-shelf toughness. Irradiations were conducted at low temperatures, < 450 F (232 C), and at an elevated temperature, ∼ 550 F (288 C).

A subsize R-specimen (0.4 in. thick), patterned after the 5/8-in. dynamic tear specimen, was employed for pre- and postirradiation R-curve determinations. R-curves were constructed by plotting specimen energy absorption per unit fracture surface area against relative crack extension distance.

Radiation exposure was revealed to have a highly detrimental effect on R-curve performance. The effect was observed for all test plates regardless of their pre-irradiation shelf toughness level. The effect encompassed R-curve performance at temperatures corresponding to the dynamic tear upper shelf and at temperatures within the dynamic tear transition regime. The primary detrimental change for the upper-shelf condition was a reduction in R-curve level. A tendency for irradiation to reduce R-curve slope was also evident. The analysis suggests that, with sufficiently high fluence, neutron irradiation can cause a transition from rising R-curve to flat R-curve behavior at upper-shelf temperatures.
Chapter 18—Pore Structure
Authors: Verbeck G
Published: March 2009

The pores, or voids, in concrete consist of pores in the hardened cement paste, entrained or entrapped air voids, and voids in the pieces of aggregate. The porosity of the aggregate is treated extensively elsewhere in this volume. Other void spaces such as honeycombing, which is the result of gross failure properly to consolidate the concrete, and bleeding channels and pockets, which result from excess water content or poor mix proportioning, are also important but are not treated in detail here, because they are the result of poor practice and are not inherent to properly prepared concrete.
Chapter 38—Abrasion Resistance, Strength, Toughness, and Related Properties
Authors: Meininger RC
Published: March 2009

Aggregates for use in concrete, and to a large extent the individual constituent particles, must possess a reasonably high degree of inherent strength, tenacity, and stability to resist, without detrimental degradation, the static and dynamic stresses, impacts, and wearing actions to which it may be exposed both in concrete production operations and, ultimately, in concrete in service. In many uses of concrete the roughest treatment to which an aggregate may be subjected in terms of mechanical forces and attrition is in the concrete production process. Actions involved in production are fairly predictable; those in service may be less predictable. In end uses such as beams, columns, covered slabs, walls, footings, and other mostly structural or architectural elements the only real strength property needed of the aggregate after the concrete is in place is that necessary to give the concrete enough strength to resist the distributed service loads. Other uses may expose aggregate near or at the surface to a variety of localized impact and abrasive stresses which will be of overriding importance in aggregate evaluation and selection. Examples include pavements and slabs exposed to heavy traffic and hydraulic structures subject to eroding forces of moving water and sediment material.
Chapter 39—Thermal Properties
Authors: Cook HK
Published: March 2009

The thermal properties of concrete aggregates are of greater or lesser concern to the user, depending upon the nature of the concrete structure and the exposure to which it is subjected. Examples of where knowledge of thermal properties are of greater concern are in the design of massive structures, such as dams, where thermal and volume stability are important and in lightweight concrete structures where insulating value is a primary factor. Except for thermal coefficient of expansion, the thermal properties of the aggregates used in normal concrete structures, such as office buildings, warehouses, pavements, and the like, seldom are considered. An understanding of the effects of the thermal properties of aggregates on the properties of concrete can have an effect on improving concrete quality and in some instances may well be mandatory.
Introduction to a Discussion of the Use of Aquatic Toxicity Tests for Evaluation of the Effects of Toxic Substances
Authors: Brungs WA , Mount DI
Published: March 2009

A variety of classes of aquatic toxicity tests are presented and discussed in relation to their ability to provide useful estimates of the environmental effects of chemicals or discharges. These classes of tests can be judged and compared numerically by several standards: ability to permit extrapolation to meaningful effect; ease and cost of conducting tests; applicability to response to a wide variety of chemicals; availability of documented detailed procedures; ecological importance and persistence of effect; and scientific and legal defensibility of the procedure. No single class of tests can be expected to be clearly superior to all others, indicating the need for a variety of testing at successive tiers of intensity of study.