218 research outputs found

    Potential Impacts of Shipping Nationalism upon a Round-the-World Shipping Service

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    Traditionally, carriers flying the American flag have concentrated on U. S. trades. The advent of new routing strategies in the container age has increased their ability to move cargo between foreign ports. As a result, their dependence on these cargoes is growing. An example is the Sea Bridge service introduced by United States Lines. With a round-the-world itinerary, this service may very well depend upon cargo carried between foreign ports in order to succeed. The ability of United States Lines to capture these foreign-to-foreign cargoes may be hampered by rising protectionism worldwide. The analysis presented here is in two separate disciplines. The first section is an analysis of the political impediments to cargo access United States Lines potentially faces with their new service. The second section is an economic analysis of the service itself to determine its viability. The relevance of protectionism to the success of the Sea Bridge service was then inferred by combining the two sections. it was established that protectionism was a threat over the long term. However, other factors, such as the level of world trade, and the actions of competitors, would play a greater role in the success or failure of the United States Lines service

    Neoplasia in IBD

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    Toward a better understanding of the placement of shotcrete: Nozzles and velocities

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    A lot of developments and improvements seen in the shotcrete industry over the last few decades have mostly arisen through the improvement of mixture designs and admixture efficiency. Unfortunately, limited efforts have been put into the modelling and optimization of one of the most important portions: the acceleration of the material through the nozzle and its subsequent travelling toward the surface. The paper first presents a clear explanation and demonstration, based on spray patterns analysis, of the differences between dry-mix and wet-mix shotcrete. It then follows with practical examples of ways to improve the technology behind the nozzle (for both processes) along with unique experimental results. The paper offers a discussion on where our efforts should be put to further reduce losses due to rebound and increase in-place shotcrete homogeneity to promote strength and durability

    UNDERSTANDING THE PUMPABILITY OF CONCRETE

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    With the increasing need for underground opening\u27s support and the increasing knowledge available today in concrete technology, shotcreting, and particularly the wet-mix process, is in great demand. Successful pumping operations however usually require a certain amount of experience. On the one hand, engineers design a mixture with high workability for ease of transport through the hose system, and on the other hand, they strive for a mixture that is relatively stiff, adhesive, and cohesive to achieve good adhesion and build-up on vertical or overhead shooting surfaces. This article presents some of the most recent research on the understanding of the key parameters affecting concrete mobility and stability under pressure, i.e. pumpability. Taking into account the mechanics of full size pumping equipment, the concept of Real Paste Content is introduced as a minimal quantity of effective paste under pressure available for mobility through a hose system. Experimental results used to validate the concept allow explanation of behavioral variations between the different concrete mixtures

    Studies on the Influence of Drying Shrinkage Test Procedure, Specimen Geometry, and Boundary Conditions on Free Shrinkage

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    Although considerable progress has been made in enhancing the use and interpretation of free ring shrinkage test, little is known about the impact of the test procedure, the specimen geometry, the surface area-to-volume (S/V) ratio exposed to drying, and the boundary conditions (sealing configuration) on the measured shrinkage. This paper highlights recent findings illustrating the influence of the test procedure, the S/V ratio exposed to drying, the geometry of specimen, and the boundary conditions. A series of experimental results are presented from free shrinkage on ring test specimens to illustrate that the test procedure can significantly influence the measured free shrinkage. A second series of experimental results are presented from specimens with different geometries and S/V ratio exposed to drying to illustrate that drying shrinkage is dependent on both the specimen geometry and the surface exposed to drying. Test results further show that, even for the same S/V ratio exposed to drying, shrinkage is strongly dependent on the specimen’s geometry and boundary conditions

    The Microbe-Derived Short Chain Fatty Acid Butyrate Targets miRNA-Dependent p21 Gene Expression in Human Colon Cancer

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    Colonic microbiota ferment non-absorbed dietary fiber to produce prodigious amounts of short chain fatty acids (SCFAs) that benefit the host through a myriad of metabolic, trophic, and chemopreventative effects. The chemopreventative effects of the SCFA butyrate are, in part, mediated through induction of p21 gene expression. In this study, we assessed the role of microRNA(miRNA) in butyrate's induction of p21 expression. The expression profiles of miRNAs in HCT-116 cells and in human sporadic colon cancers were assessed by microarray and quantitative PCR. Regulation of p21 gene expression by miR-106b was assessed by 3′ UTR luciferase reporter assays and transfection of specific miRNA mimics. Butyrate changed the expression of 44 miRNAs in HCT-116 cells, many of which were aberrantly expressed in colon cancer tissues. Members of the miR-106b family were decreased in the former and increased in the latter. Butyrate-induced p21 protein expression was dampened by treatment with a miR-106b mimic. Mutated p21 3′UTR-reporter constructs expressed in HCT-116 cells confirmed direct miR-106b targeting. Butyrate decreased HCT-116 proliferation, an effect reversed with the addition of the miR-106b mimic. We conclude that microbe-derived SCFAs regulate host gene expression involved in intestinal homeostasis as well as carcinogenesis through modulation of miRNAs

    Analysis of genome-wide 5-hydroxymethylation of blood samples stored in different anticoagulants: Opportunities for the expansion of clinical resources for epigenetic research

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    Background: Elucidating epigenetic mechanisms could provide new biomarkers for disease diagnosis and prognosis. Technological advances allow genome-wide profiling of 5-hydroxymethylcytosines (5hmC) in liquid biopsies. 5hmC-Seal followed by NGS is a highly sensitive technique for 5hmC biomarker discovery in cfDNA. Currently, 5hmC Seal is optimized for EDTA blood collection. We asked whether heparin was compatible with 5hmC Seal as many clinical and biobanked samples are stored in heparin. Methods: We obtained 60 samples in EDTA matched to 60 samples in heparin from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Samples were comprised of 30 controls and 30 individuals who were later diagnosed with colon cancer. We profiled genome-wide 5hmC in cfDNA using 5hmC-Seal assay followed by NGS. The 5hmC profiling data from samples collected in EDTA were systematically compared to those in heparin across various genomic features. Results: cfDNA isolation and library construction appeared comparable in heparin vs. EDTA. Typical genomic distribution patterns of 5hmC, including gene bodies and enhancer markers, were comparable in heparin vs. EDTA. 5hmC analysis of cases and controls yielded highly correlated differential features suggesting that both anticoagulants were compatible with 5hmC Seal assay. Conclusions: While not currently recommended for the 5hmC-Seal protocol, blood samples stored in heparin were successfully used to generate analysable and biologically relevant genome-wide 5hmC profiling. Our findings are the first to support opportunities to expand the biospecimen resource to heparin samples for 5hmC Seal and perhaps other PCR-based technologies in epigenetic research.</p
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