Geotechnical Baseline Reports (GBRs) have become a prevalent risk sharing mechanism on North American tunneling projects as they are based on the following risk allocation concept: the subsurface ...ground conditions described within the GBR are the financial responsibility of the Contractor, whereas encountered conditions which exceed those described belong to the Owner. This interpretation is intended to reduce project bid prices due to subsurface ground conditions uncertainty and the geotechnical rationale for a differing site conditions claim. However, recent tunnel project case studies have used the GBR as a risk transfer mechanism by presenting a conservative and/or limited interpretation of the expected ground conditions. In particular, the expected ground conditions are described with a summary of the intact and rockmass properties and empirical rockmass classification systems. This research has shown that the application of intact rock properties and rockmass classification systems to describe the various rockmasses along the tunnel alignment leads to rockmass behavioural uncertainty. Empirical rockmass classification systems are not able to adequately capture the effects of geologic uncertainty and the collective impact of the individual controls on rockmass behaviour. A new rock engineering design tool was developed which utilized geologic uncertainty and the capabilities of numerical modelling methods to predict and quantify rockmass behaviours. The 3D Rockmass Behaviour Map reduces subsurface ground conditions uncertainty as the range of possible rockmass behaviours is presented as a function of the three critical geomechanics parameters. Quantifying rockmass behaviours per tunnel domain demonstrates the effects of geologic uncertainty with rockmass behaviour mode switching. GBRs should include this 3D Rockmass Behaviour Map and quantified rockmass behaviours as these tools reduce uncertainty in the expected ground conditions and provide a greater understanding of the anticipated rockmass behaviours. Rather than using a conservative GBR which shifts subsurface ground conditions risk to a Contractor, this improved prediction of the expected ground conditions may result in better subsurface risk allocation, reduced construction contingencies, aid excavation means and methods selection, reduced geotechnical basis for a differing site condition claim, and provide greater certainty in the final project price and schedule.
To assess the immunological changes occurring during filarial infection with or without elephantiasis, 145 patients in different clinical groups from an endemic area in Indonesia were compared with ...respect to plasma levels of both soluble CD25 (sCD25) and sCD27; interleukin-4 (IL-4) and interferon-gamma release by peripheral blood mononuclear cells was also measured in a smaller subset of individuals. Levels of sCD27 were significantly elevated in elephantiasis and microfilaremic patients compared with endemic normals (p < 0.002), whereas sCD25 levels remained low in microfilaremics and was only slightly elevated in elephantiasis patients compared with endemic normals (p < 0.02). As activated T cell populations release both sCD27 and sCD25, these findings imply that there is filarial-driven activation of a T cell subset that releases sCD27 rather than sCD25. The expansion of a particular T cell population by filarial parasites is further suggested by the enhancement in both IL-4-producing and CD4+CD27-T cells in PBMC from elephantiasis and microfilaremic patients compared with endemic normals. More detailed characterization and comparison of CD27-lymphocytes from these individuals may identify mechanisms involved in the pathogenesis of lymphatic filariasis.
A number of reports have described the monoallelic expression of murine cytokine genes. Here we describe the monoallelic expression of the human IL-1alpha gene in CD4 super(+) T cells. Analysis of ...peripheral blood T cell clones derived from healthy individuals revealed that the IL-1alpha gene shows predominantly monoallelic expression. Monoallelic expression was observed in Th0, Th1, and Th2 cell clones. In addition, we demonstrate monoallelic expression in T cell clones from rheumatoid arthritis patients derived from synovial fluid of the knee joint, suggesting that the occurrence of this phenomenon is not different from that in clones derived from healthy individuals. The finding of monoallelic expression of a cytokine gene in human CD4 super(+) T cell clones provides evidence for allele-specific silencing/activation as another layer of regulation of IL-1alpha gene expression.
The occurrence of monoallelic expression of cytokine genes in single cells has been convincingly demonstrated, but there have been few reports of this phenomenon in T cell clones. Here we describe ...studies on the expression of alleles of the human genes encoding IL-2, IL-3, IL-4, and IL-13 in human CD4 super(+) T cell clones. In contrast to the results reported in mouse T cell clones and single human T cells, we found no evidence for the monoallelic expression of the IL-2, IL-3, and IL-13 genes. The gene for IL-4 showed an imbalance in expression from each allele, indicating differential expression of IL-4 alleles within or between IL-4-expressing cells.
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