66 research outputs found

    Dynamic Shear Modulus and Damping Ratio Predicted by a Unified 3-D Critical State Bounding Surface Plasticity Model

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    A unified 3-d critical state bounding surface plasticity model (gUTS) has been developed which is able to provide realistic simulations of the behavior of clays, silts and sands both in drained and undrained conditions over a wide range of monotonic and complex cyclic paths. A strong feature of this model is its ability to treat loose and dense states of the same material with a single set of material constants. The link between the two states is made by introducing an apparent normal consolidation line for sands and adopting a volumetric plastic strain hardening/softening model (similar to the critical state models for clays). This and other features enable the model to degenerate to simpler forms including the classic modified Cam-Clay formulation. To date, simulations have concentrated on the medium to high strain range (10-3 to 10-1). To address a wider strain range, this paper reports on a new series of simulations for sand in the range 10-6 to 10-

    The Flagellum of Pseudomonas aeruginosa Is Required for Resistance to Clearance by Surfactant Protein A

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    Surfactant protein A (SP-A) is an important lung innate immune protein that kills microbial pathogens by opsonization and membrane permeabilization. We investigated the basis of SP-A-mediated pulmonary clearance of Pseudomonas aeruginosa using genetically-engineered SP-A mice and a library of signature-tagged P. aeruginosa mutants. A mutant with an insertion into flgE, the gene that encodes flagellar hook protein, was preferentially cleared by the SP-A(+/+) mice, but survived in the SP-A(-/-) mice. Opsonization by SP-A did not play a role in flgE clearance. However, exposure to SP-A directly permeabilized and killed the flgE mutant, but not the wild-type parental strain. P. aeruginosa strains with mutation in other flagellar genes, as well as mucoid, nonmotile isolates from cystic fibrosis patients, were also permeabilized by SP-A. Provision of the wild-type fliC gene restored the resistance to SP-A-mediated membrane permeabilization in the fliC-deficient bacteria. In addition, non-mucoid, motile revertants of CF isolates reacquired resistance to SP-A-mediated membrane permeability. Resistance to SP-A was dependent on the presence of an intact flagellar structure, and independent of flagellar-dependent motility. We provide evidence that flagellar-deficient mutants harbor inadequate amounts of LPS required to resist membrane permeabilization by SP-A and cellular lysis by detergent targeting bacterial outer membranes. Thus, the flagellum of P. aeruginosa plays an indirect but important role resisting SP-A-mediated clearance and membrane permeabilization

    Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

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    The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe

    Meta-analysis of genome-wide association studies discovers multiple loci for chronic lymphocytic leukemia.

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    Chronic lymphocytic leukemia (CLL) is a common lymphoid malignancy with strong heritability. To further understand the genetic susceptibility for CLL and identify common loci associated with risk, we conducted a meta-analysis of four genome-wide association studies (GWAS) composed of 3,100 cases and 7,667 controls with follow-up replication in 1,958 cases and 5,530 controls. Here we report three new loci at 3p24.1 (rs9880772, EOMES, P=2.55 × 10(-11)), 6p25.2 (rs73718779, SERPINB6, P=1.97 × 10(-8)) and 3q28 (rs9815073, LPP, P=3.62 × 10(-8)), as well as a new independent SNP at the known 2q13 locus (rs9308731, BCL2L11, P=1.00 × 10(-11)) in the combined analysis. We find suggestive evidence (P<5 × 10(-7)) for two additional new loci at 4q24 (rs10028805, BANK1, P=7.19 × 10(-8)) and 3p22.2 (rs1274963, CSRNP1, P=2.12 × 10(-7)). Pathway analyses of new and known CLL loci consistently show a strong role for apoptosis, providing further evidence for the importance of this biological pathway in CLL susceptibility

    Progression from normal breast pathology to breast cancer is associated with increasing prevalence of mouse mammary tumor virus-like sequences in men and women

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    Mouse mammary tumor virus (MMTV)-like sequences have been found in up to 40% of breast cancer samples but in <2% of normal breast tissue samples from Australian women studied by our group. Screening of a larger and more diverse cohort of female breast cancer samples has now shown a correlation of MMTV-like sequences with the severity (grade) of breast cancer. Thirty-two percent (43 of 136) of female breast cancer samples were positive for MMTV-like sequences when screened using PCR. A significant gradient of MMTV positivity was observed with increasing severity of cancer from 23% of infiltrating ductal carcinoma (IDC) grade I tumors to 34% of IDC grade II tumors (P = 0.00034) and 38% of IDC grade III tumors (P = 0.00002). We also report for the first time the detection of MMTV-like sequences in 62% (8 of 13) of male breast cancer samples and 19% (10 of 52) of male gynecomastia samples screened. MMTV-like sequences were demonstrated in various premalignant breast lesions of females, including fibroadenoma (20%) and fibrocystic disease (28%) samples, at a significantly higher prevalence than that seen in normal breast tissue (1.8%; P = 0.00001). Study of a longitudinal cohort of female breast cancer patients indicated that MMTV was co-incident with tumor but was not present when tumor was absent on histology. These results support the association of MMTV-like sequences with development of breast tumors in men and women and suggest association of MMTV with increasing severity of cancer

    Progression from Normal Breast Pathology to Breast Cancer Is Associated with Increasing Prevalence of Mouse Mammary Tumor Virus-Like Sequences in Men and Women

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    Mouse mammary tumor virus (MMTV)-like sequences have been found in up to 40% of breast cancer samples but in <2% of normal breast tissue samples from Australian women studied by our group. Screening of a larger and more diverse cohort of female breast cancer samples has now shown a correlation of MMTV-like sequences with the severity (grade) of breast cancer. Thirty-two percent (43 of 136) of female breast cancer samples were positive for MMTV-like sequences when screened using PCR. A significant gradient of MMTV positivity was observed with increasing severity of cancer from 23% of infiltrating ductal carcinoma (IDC) grade I tumors to 34% of IDC grade II tumors (P = 0.00034) and 38% of IDC grade III tumors (P = 0.00002). We also report for the first time the detection of MMTV-like sequences in 62% (8 of 13) of male breast cancer samples and 19% (10 of 52) of male gynecomastia samples screened. MMTV-like sequences were demonstrated in various premalignant breast lesions of females, including fibroadenoma (20%) and fibrocystic disease (28%) samples, at a significantly higher prevalence than that seen in normal breast tissue (1.8%; P = 0.00001). Study of a longitudinal cohort of female breast cancer patients indicated that MMTV was co-incident with tumor but was not present when tumor was absent on histology. These results support the association of MMTV-like sequences with development of breast tumors in men and women and suggest association of MMTV with increasing severity of cancer

    Connecting People and Place Prosperity: Workforce Development and Urban Planning in Scholarship and Practice

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    In recent years, the field of workforce development has emerged as a distinct area of policy and practice. While planning scholars have begun to engage with the workforce development field, its relevance and points of connection to planning scholarship remain underexplored. This article attempts to define the workforce development field by articulating its core concerns as well as its domains of practice and scholarship outside the planning field. The article locates workforce development within three stands of planning scholarship, concluding that workforce development represents an important bridge for planners between “place” and “people” prosperity within communities

    Union autonomy in context: An international comparison

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    This is the second of two linked articles on the question of union autonomy; the first appeared in the previous issue of this journal. It considers state control and approach to union autonomy in the wider context of state controls on unions' bargaining activities including industrial action. Two questions are posed: whether there is any “balance” between state respect for union autonomy and state confidence that union collective bargaining activities take place within a legally prescribed framework; and how the state in the UK was able to shift so rapidly from the traditional, voluntary approach and the incipient neo-corporatism of the 1970s, to the detailed and onerous regulation of union internal and external activities in the 1980s and 1990s
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