Monitoring and Failure Analysis of Corroded Bridge Cables under Fatigue Loading Using Acoustic Emission Sensors

Cables play an important role in cable-stayed systems, but are vulnerable to corrosion and fatigue damage. There is a dearth of studies on the fatigue damage evolution of corroded cable. In the present study, the acoustic emission (AE) technology is adopted to monitor the fatigue damage evolution process. First, the relationship between stress and strain is determined through a tensile test for corroded and non-corroded steel wires. Results show that the mechanical performance of corroded cables is changed considerably. The AE characteristic parameters for fatigue damage are then established. AE energy cumulative parameters can accurately describe the fatigue damage evolution of corroded cables. The failure modes in each phase as well as the type of acoustic emission source are determined based on the results of scanning electron microscopy. The waveform characteristics, damage types, and frequency distribution of the corroded cable at different damage phases are collected. Finally, the number of broken wires and breakage time of the cables are determined according to the variation in the margin index

Dynamics of Spontaneous Magnetization Reversal in Exchange Biased Heterostructures

The dependence of thermally induced spontaneous magnetization reversal on time-dependent cooling protocols was studied. Slower cooling and longer waiting close to the N\`{e}el temperature of the antiferromagnet ($T_N$) enhances the magnetization reversal. Cycling the temperature around $T_N$ leads to a thermal training effect under which the reversal magnitude increases with each cycle. These results suggest that spontaneous magnetization reversal is energetically favored, contrary to our present understanding of positive exchange bias

Evaluation of gene importance in microarray data based upon probability of selection

BACKGROUND: Microarray devices permit a genome-scale evaluation of gene function. This technology has catalyzed biomedical research and development in recent years. As many important diseases can be traced down to the gene level, a long-standing research problem is to identify specific gene expression patterns linking to metabolic characteristics that contribute to disease development and progression. The microarray approach offers an expedited solution to this problem. However, it has posed a challenging issue to recognize disease-related genes expression patterns embedded in the microarray data. In selecting a small set of biologically significant genes for classifier design, the nature of high data dimensionality inherent in this problem creates substantial amount of uncertainty. RESULTS: Here we present a model for probability analysis of selected genes in order to determine their importance. Our contribution is that we show how to derive the P value of each selected gene in multiple gene selection trials based on different combinations of data samples and how to conduct a reliability analysis accordingly. The importance of a gene is indicated by its associated P value in that a smaller value implies higher information content from information theory. On the microarray data concerning the subtype classification of small round blue cell tumors, we demonstrate that the method is capable of finding the smallest set of genes (19 genes) with optimal classification performance, compared with results reported in the literature. CONCLUSION: In classifier design based on microarray data, the probability value derived from gene selection based on multiple combinations of data samples enables an effective mechanism for reducing the tendency of fitting local data particularities

The gene expression data of Mycobacterium tuberculosis based on Affymetrix gene chips provide insight into regulatory and hypothetical genes

<p>Abstract</p> <p>Background</p> <p>Tuberculosis remains a leading infectious disease with global public health threat. Its control and management have been complicated by multi-drug resistance and latent infection, which prompts scientists to find new and more effective drugs. With the completion of the genome sequence of the etiologic bacterium, <it>Mycobacterium tuberculosis</it>, it is now feasible to search for new drug targets by sieving through a large number of gene products and conduct genome-scale experiments based on microarray technology. However, the full potential of genome-wide microarray analysis in configuring interrelationships among all genes in <it>M. tuberculosis </it>has yet to be realized. To date, it is only possible to assign a function to 52% of proteins predicted in the genome.</p> <p>Results</p> <p>We conducted a functional-genomics study using the high-resolution Affymetrix oligonucleotide GeneChip. Approximately one-half of the genes were found to be always expressed, including more than 100 predicted conserved hypotheticals, in the genome of <it>M. tuberculosis </it>during the log phase of in vitro growth. The gene expression profiles were analyzed and visualized through cluster analysis to epitomize the full details of genomic behavior. Broad patterns derived from genome-wide expression experiments in this study have provided insight into the interrelationships among genes in the basic cellular processes of <it>M. tuberculosis</it>.</p> <p>Conclusion</p> <p>Our results have confirmed several known gene clusters in energy production, information pathways, and lipid metabolism, and also hinted at potential roles of hypothetical and regulatory proteins.</p

14-02 Developing Public Health Performance Measures to Capture the Effects of Transportation Facilities on Multiple Public Health Outcomes

Increasingly, federal transportation and public health agencies are working together to identify transportation investments that improve public health. Investments in transportation infrastructure represent one method to utilize transportation to improve public health outcomes. The ideal transportation investment is one that not only provides safe access for pedestrians, bicyclists, motorists and transit riders, but it also promotes more utilitarian or recreational trips for walking and biking in an environment of safe air quality. However, public health objectives can be at conflict when designing transportation infrastructure to support active commuting. For example, infrastructure investments may be made that promote physical activity through utilitarian commuting, yet at the same time, the investment may be made in an area that is characterized by poor air quality or creates an unsafe condition. The purpose of the research is to identify potential performance measures that can foster improved decision making around these investments. The key research contribution is the development of performance measures that can be used in the field to evaluate multiple public health concerns and improve decision making. Secondly, it advances strategies to effectively capture the dimension of safety and physical activity in a manner that considers the conditions under which pedestrian and bicycling activity is likely to increase. The objectives of the project are accomplished through the use and integration of multiple methods, including student-based project learning, expert surveys, content analysis and quantitative statistical techniques

Dynamic Spin-Polarized Resonant Tunneling in Magnetic Tunnel Junctions

Precisely engineered tunnel junctions exhibit a long sought effect that occurs when the energy of the electron is comparable to the potential energy of the tunneling barrier. The resistance of metal-insulator-metal tunnel junctions oscillates with an applied voltage when electrons that tunnel directly into the barrier's conduction band interfere upon reflection at the classical turning points: the insulator-metal interface, and the dynamic point where the incident electron energy equals the potential barrier inside the insulator. A model of tunneling between free electron bands using the exact solution of the Schroedinger equation for a trapezoidal tunnel barrier qualitatively agrees with experiment.Comment: 4pgs, 3 fig

No Association of Obesity and Type 2 Diabetes Mellitus Related Genetic Variants With Colon Cancer

Background: Obesity and type 2 diabetes mellitus (T2D) are known risk factors for colon cancer. Recent reports from a number of genome wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) associated with obesity and T2D. Here we tested the hypothesis that these SNPs may also be associated with risk of colon cancer. Methods: We genotyped nine SNPs reported in GWAS of obesity and/or T2D, including SNPs in HHEX, KCNJ11, SLC30A8, FTO, CDKN2, CDKAL1, TCF2, and the rs9300039 SNP in an intergenic region, in 561 colon cancer cases and 721 population controls. Results: None of these SNPs were statistically significantly associated with colon cancer in our sample. Conclusions: Overall, these results suggest that these obesity and T2D genetic susceptibility loci are unlikely to influence the risk of colon cancer

Curcumin Mitigates Neuropathic-Induce Muscle Atrophy by Suppressing CaMK2/NF-kB Pathway

Neuropathy can induce inflammation that results in muscle atrophy. Curcumin has been shown to exert an anti-inflammatory effect, preserving muscle mass in diabetic rats. However, the mechanism of curcumin to preserve muscle mass in neuropathy is not known. PURPOSE: To examine the effect of curcumin on the intramuscular inflammation and muscle cross-sectional area (CSA) in a neuropathy rodent model. METHODS: Twelve rats were randomly assigned to three groups: sham (CON), spinal nerve ligation (SNL), and SNL+100curcumin/kg BW (100CUR). The right (R) lumbosacral section (i.e., L5/L6) of the spinal cord was ligated (SNL and 100CUR) or sham surgery (CON) was performed, whereas the contralateral side (left: L) was served as their own control. Rats were fed with a control diet without (i.e., CON and SNL) or with (i.e., 100CUR) curcumin supplementation for 4 weeks. Plantaris (left and right) and tibialis anterior (TA; right) muscles were collected. TA was stained for dystrophin to measure CSA. Left and right plantaris were analyzed for protein content for AChR, CaMK2, CaMK2Thr286, CaMK2Thr286/CaMK2, NF-κB, NF-κBSer536, NF-κBSer536/NF-κB, IL-1β, and GAPDH. Each protein was normalized to GAPDH then to the CON. RESULTS: A significant (p ≤ 0.05) group effect was observed for TA CSA and a group x leg interaction effect was observed for CaMK2Thr286/CaMK2, NF-κBSer536, IL-1β protein content. For muscle CSA, CON (9027.33 ± 603.39 μm2) and 100CUR (8853.68 ± 696.73 μm2) were larger than SNL (4771.01 ± 539.69 μm2). No difference was observed in CSA between CON and 100CUR. Additionally, when compared between left and right plantaris muscles, only SNL had greater CaMK2Thr286/CaMK2 (R: 2.63 ± 1.87 vs. L: 1.56 ± 1.65), NF-κBSer536 (R: 1.85 ± 0.83 vs. L: 0.55 ± 0.33), and IL-1β (R: 2.11 ± 1.32 vs. L: 0.65 ± 0.29) protein content in the right than the left leg, whereas, no difference was observed for left leg among groups. For NF-κBSer536, SNL (1.85 ± 0.83) was greater than 100CUR (0.91 ± 0.52) in the right leg. No significant differences were observed for AChR, CaMK2, CaMK2Thr286, and NF-κBSer536/NF-κB. CONCLUSION: In a neuropathic model, muscle atrophy was observed with concomitant increase in CaMK2/NF-κB/IL-1β activation in the ipsilateral plantaris. Curcumin supplementation appears to mitigate this inflammatory response and muscle mass loss