72 research outputs found

    Safety Climate as an Indicator and Predictor of Safety Performance: A Case Study

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    This study compared and objectively gauged the safety climate in the manufacturing facilities (high safety performing vs. low safety performing) to identify the most impactful areas to focus to reduce or prevent workplace injuries. In order to accomplish the study objective, we employed the Nordic Safety Climate Questionnaire (NOSACQ-50) consisted of 50 items across seven dimensions. A total of 116 operations employees in the paper laminate manufacturing completed the survey. The two sites were both within the United States and had structured the same operations. The results of the comparisons showed that there was a significant difference in the total scores for the sites. The high performance site had significantly higher NOSACQ-50 scores than the underperforming site in all dimensions. The high performing site had the greater safety climate scores in the area of “management safety priority & ability”. The underperforming site recorded comparatively lower scores in the areas of “management safety empowerment”, “group safety priority”, and “worker safety commitment”. We provided the recommendations of three focus areas: commitment, involvement, and accountability. The outcomes from this study could be useful to apply resources and focus to the appropriate areas in order to make safety improvements. In turn, improving safety climate can have positive impacts on increasing employee safety while improving the viability of the organization

    Redox Regulation Facilitates Optimal Peptide Selection by MHC Class I during Antigen Processing

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    SummaryActivated CD8+ T cells discriminate infected and tumor cells from normal self by recognizing MHC class I-bound peptides on the surface of antigen-presenting cells. The mechanism by which MHC class I molecules select optimal peptides against a background of prevailing suboptimal peptides and in a considerably proteolytic ER environment remained unknown. Here, we identify protein disulfide isomerase (PDI), an enzyme critical to the formation of correct disulfide bonds in proteins, as a component of the peptide-loading complex. We show that PDI stabilizes a peptide-receptive site by regulating the oxidation state of the disulfide bond in the MHC peptide-binding groove, a function that is essential for selecting optimal peptides. Furthermore, we demonstrate that human cytomegalovirus US3 protein inhibits CD8+ T cell recognition by mediating PDI degradation, verifying the functional relevance of PDI-catalyzed peptide editing in controlling intracellular pathogens. These results establish a link between thiol-based redox regulation and antigen processing

    Human Cytomegalovirus UL18 Utilizes US6 for Evading the NK and T-Cell Responses

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    Human cytomegalovirus (HCMV) US6 glycoprotein inhibits TAP function, resulting in down-regulation of MHC class I molecules at the cell surface. Cells lacking MHC class I molecules are susceptible to NK cell lysis. HCMV expresses UL18, a MHC class I homolog that functions as a surrogate to prevent host cell lysis. Despite a high level of sequence and structural homology between UL18 and MHC class I molecules, surface expression of MHC class I, but not UL18, is down regulated by US6. Here, we describe a mechanism of action by which HCMV UL18 avoids attack by the self-derived TAP inhibitor US6. UL18 abrogates US6 inhibition of ATP binding by TAP and, thereby, restores TAP-mediated peptide translocation. In addition, UL18 together with US6 interferes with the physical association between MHC class I molecules and TAP that is required for optimal peptide loading. Thus, regardless of the recovery of TAP function, surface expression of MHC class I molecules remains decreased. UL18 represents a unique immune evasion protein that has evolved to evade both the NK and the T cell immune responses

    Three-Dimensional Finite Element Simulations of a Turbulent Push-Pull Ventilation System

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    A finite element model is used to simulate a push-pull ventilation system in three spatial dimensions. The turbulent Navier-Stokes equations and the turbulence kinetic energy equation are solved employing a one equation turbulence model. A test case is a simple push-pull system consisting of a square jet and square hood. Velocity and turbulence fields are calculated for the test case with cross draft velocities of 0, 100, and 250 fpm. Measurements of velocity and turbulence fields were performed to validate the numerical predictions using a visualization technique and hot-film anemometry. Velocity field predictions were reasonable, however, turbulence predictions were not as good. The discrepancy is probably due to an inadequate turbulence model and numerical errors resulting from calculations on coarse grids.Master of Science in Environmental Engineerin

    A signal for retention of cytochrome P450 2C1 in the endoplasmic reticulum

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    To determine whether the N-terminal hydrophobic sequence is also responsible for retention, the N-terminal 29 amino acids of cytochrome P450 2C1, with and without an additional 29 amino acids containing an N-glycosylation site, were fused to a soluble cytoplasmic protein, Escherichia coli β\beta-galactosidase, or to a secreted protein, Escherichia coli alkaline phosphatase, and the hybrid proteins were expressed in COS1 cells and cellular localization was determined by subcellular fractionation, immunolocalization and the glycosylation state of the proteins. Both the β\beta-galactosidase and alkaline phosphatase hybrid proteins were retained in the endoplasmic reticulum establishing that a specific sequence or property in the N-terminal 29 amino acids is responsible for ER retention. To further examine the possibility that retention of proteins with a large cytoplasmic domain is the default pathway, the cellular distributions of a series of P450 2C1 and EGFR chimeric proteins were examined. The data indicate that the cytoplasmic domain of the protein also has retention properties. Protein containing only the transmembrane domain of EGFR at the amino-terminus and the EGFR cytoplasmic domain were transported to the plasma membrane, while the equivalent construction with the cytoplasmic domain of cytochrome P450 was retained in the ER. The reciprocal construction with the N-terminal sequence of P450 and the cytoplasmic domain of EGFR was retained in the ER confirming the previous studies that the N-terminal sequence has ER retention properties. The retention properties of the normally N-terminal 29 amino acids was dependent on their position in the protein. We subjected the N-terminal region of P450 to extensive mutagenesis to further define the specific sequence requirements for retention. We demonstrated that the C-terminal flanking sequences following the transmembrane domain are not important for ER retention. Substitutions of either leucine or alanine for non-leucine residues did not alter the ER retention properties of the transmembrane domain. Therefore, it seems likely that another property like secondary structure, hydrophobicity, hydrophilicity, or length of the transmembrane domain of P450 may be important for ER retention.Ope

    Interplay between RNASEH2 and MOV10 controls LINE-1 retrotransposition

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    Long interspersed nuclear element 1 is an autonomous non-long terminal repeat retrotransposon that comprises similar to 17% of the human genome. Its spontaneous retrotransposition and the accumulation of heritable L1 insertions can potentially result in genome instability and sporadic disorders. Moloney leukemia virus 10 homolog (MOV10), a putative RNA helicase, has been implicated in inhibiting L1 replication, although its underlying mechanism of action remains obscure. Moreover, the physiological relevance of MOV10-mediated L1 regulation in human disease has not yet been examined. Using a proteomic approach, we identified RNASEH2 as a binding partner of MOV10. We show that MOV10 interacts with RNASEH2, and their interplay is crucial for restricting L1 retrotransposition. RNASEH2 and MOV10 co-localize in the nucleus, and RNASEH2 binds to L1 RNAs in a MOV10-dependent manner. Small hairpin RNA-mediated depletion of either RNASEH2A or MOV10 results in an accumulation of L1-specific RNA-DNA hybrids, suggesting they contribute to prevent formation of vital L1 heteroduplexes during retrotransposition. Furthermore, we show that RNASEH2-MOV10-mediated L1 restriction downregulates expression of the rheumatoid arthritis-associated inflammatory cytokines and matrix-degrading proteinases in synovial cells, implicating a potential causal relationship between them and disease development in terms of disease predisposition. c. The Author(s) 2018

    Indirect Prediction of Welding Fume Diffusion inside a Room Using Computational Fluid Dynamics

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    Welding is an important and widely used process in the manufacturing and maintenance of various works involving metals and alloys. While welding has broad applications, the welding fume generated during the process has impacts on workers’ health, which needs to be addressed. One of the major steps that can be undertaken to take care of this issue is the use of ventilation, which requires knowledge of characteristics and dispersion of the welding fume in the workers’ breathing zone. It is difficult to assess welding fume dispersion from manual measurement due to numerous welding processes and sufficient data requirement. Numerical prediction of welding fume is dubious due to several errors. This paper considers the use of numerically predicted CO2 concentrations to indirectly predict welding fume distribution in workshops. This is based on the assumption that if the particles are sufficiently small size, they follow the diffusion pattern of gases. Experiments are carried out in a room with an opening and a welding fume generation system for measurement of CO2 and fume diffusion. The results show high possibility of predicting welding fume concentration based on Computational Fluid Dynamics (CFD) simulated CO2 concentration with a correlation coefficient of 0.74

    Determinant for Endoplasmic Reticulum Retention in the Luminal Domain of the Human Cytomegalovirus US3 Glycoprotein

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    US3 of human cytomegalovirus is an endoplasmic reticulum resident transmembrane glycoprotein that binds to major histocompatibility complex class I molecules and prevents their departure. The endoplasmic reticulum retention signal of the US3 protein is contained in the luminal domain of the protein. To define the endoplasmic reticulum retention sequence in more detail, we have generated a series of deletion and point mutants of the US3 protein. By analyzing the rate of intracellular transport and immunolocalization of the mutants, we have identified Ser(58), Glu(63), and Lys(64) as crucial for retention, suggesting that the retention signal of the US3 protein has a complex spatial arrangement and does not comprise a contiguous sequence of amino acids. We also show that a modified US3 protein with a mutation in any of these amino acids maintains its ability to bind class I molecules; however, such mutated proteins are no longer retained in the endoplasmic reticulum and are not able to block the cell surface expression of class I molecules. These findings indicate that the properties that allow the US3 glycoprotein to be localized in the endoplasmic reticulum and bind major histocompatibility complex class I molecules are located in different parts of the molecule and that the ability of US3 to block antigen presentation is due solely to its ability to retain class I molecules in the endoplasmic reticulum

    Stretch & Flex Programs: Effects on the Reduction of Musculoskeletal Disorders & Injuries

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    This study evaluated the impact of stretch-and-flex (SF) programs on construction worker safety and health by comparing construction firms’ safety performance/injury rates before and after the implementation of workplace SF programs.Sprain/strain was the most frequent musculoskeletal disorder (MSD) injury type followed by rotator cuff injury, back injury, tendinitis, epicondylitis and carpal tunnel syndrome due to overexertion, motion/position, tools/machinery, lifting improperly and wear/tear.The authors analyzed information on pre- and post-SF program implementation and safety performance (i.e., number of MSDs, OSHA-recordable injuries, lost-workday injuries).Data suggest that work-related MSDs and injuries can be reduced by implementing SF programs
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