238 research outputs found

    Implementation of a disability management policy in a large healthcare employer: a quasi-experimental, mixed-method evaluation

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    Objective: This study describes the process and outcomes of the implementation of a strengthened disability management policy in a large Canadian healthcare employer. Key elements of the strengthened policy included an emphasis on early contact, the training of supervisors and the integration of union representatives in return-to-work (RTW) planning. Design: The study applied mixed methods, combining a process evaluation within the employer and a quasi-experimental outcome evaluation between employers for a 3-year period prior to and following policy implementation in January 2012. Participants: Staff in the implementation organisation (n=4000) and staff in a peer group of 29 large hospitals (n=1 19 000). Outcomes: Work disability episode incidence and duration. Results: Both qualitative and quantitative measures of the implementation process were predominantly positive. Over the 6-year observation period, there were 624 work disability episodes in the organisation and 8604 in the comparison group of 29 large hospitals. The annual per cent change in episode incidence in the organisation was −5.6 (95% CI −9.9 to −1.1) comparable to the annual per cent change in the comparison group: −6.2 (-7.2 to –5.3). Disability episode durations also declined in the organisation, from a mean of 19.4 days (16.5, 22.3) in the preintervention period to 10.9 days (8.7, 13.2) in the postintervention period. Reductions in disability durations were also observed in the comparison group: from a mean of 13.5 days (12.9, 14.1) in the 2009–2011 period to 10.5 days (9.9, 11.1) in the 2012–2014 period. Conclusion: The incidence of work disability episodes and the durations of work disability declined strongly in this hospital sector over the 6-year observation period. The implementation of the organisation’s RTW policy was associated with larger reductions in disability durations than observed in the comparison group

    Implementation of a disability management policy in a large healthcare employer: a quasi-experimental, mixed-method evaluation

    Get PDF
    Objective: This study describes the process and outcomes of the implementation of a strengthened disability management policy in a large Canadian healthcare employer. Key elements of the strengthened policy included an emphasis on early contact, the training of supervisors and the integration of union representatives in return-to-work (RTW) planning. Design: The study applied mixed methods, combining a process evaluation within the employer and a quasi-experimental outcome evaluation between employers for a 3-year period prior to and following policy implementation in January 2012. Participants: Staff in the implementation organisation (n=4000) and staff in a peer group of 29 large hospitals (n=1 19 000). Outcomes: Work disability episode incidence and duration. Results: Both qualitative and quantitative measures of the implementation process were predominantly positive. Over the 6-year observation period, there were 624 work disability episodes in the organisation and 8604 in the comparison group of 29 large hospitals. The annual per cent change in episode incidence in the organisation was −5.6 (95% CI −9.9 to −1.1) comparable to the annual per cent change in the comparison group: −6.2 (-7.2 to –5.3). Disability episode durations also declined in the organisation, from a mean of 19.4 days (16.5, 22.3) in the preintervention period to 10.9 days (8.7, 13.2) in the postintervention period. Reductions in disability durations were also observed in the comparison group: from a mean of 13.5 days (12.9, 14.1) in the 2009–2011 period to 10.5 days (9.9, 11.1) in the 2012–2014 period. Conclusion: The incidence of work disability episodes and the durations of work disability declined strongly in this hospital sector over the 6-year observation period. The implementation of the organisation’s RTW policy was associated with larger reductions in disability durations than observed in the comparison group

    The manufacture of honeycomb cores using Fused Deposition Modeling

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    Sandwich panels are used in many industries for the advantageous properties of high stiffness, good strength to weight ratio, and impact resistance. This paper investigates properties of thin-walled cores manufactured through Fused Deposition Modeling (FDM); a process which, through a wider design space, could improve the functionality of sandwich panels. The bond strength between the layers of thin walls manufactured through FDM was evaluated through tensile testing. To measure the effect of modified manufacturing speeds, wall thicknesses were varied through the flow rate and nozzle speed. Honeycomb cores using FDM were produced with different toolpaths, and compared with an example of an industry standard Nomex honeycomb core. During tensile testing, thick-walled FDM components exhibited a more ductile failure with a lower yield point when compared to thinner specimens. The ultimate tensile stress remained constant across samples within each of the tested ABS and PLA polymers used. Honeycomb cores produced using FDM were found to have a higher compressive failure force than Nomex honeycomb, and a lower specific strength. The force–displacement curves of compressive failure show a ductile response for thick specimens, consistent with the previous result. These results, combined with the increased flexibility of additive manufacture technologies, could provide a method of manufacturing high strength cores with complex geometry

    The manufacture of honeycomb cores using Fused Deposition Modeling

    Get PDF
    Sandwich panels are used in many industries for the advantageous properties of high stiffness, good strength to weight ratio, and impact resistance. This paper investigates properties of thin-walled cores manufactured through Fused Deposition Modeling (FDM); a process which, through a wider design space, could improve the functionality of sandwich panels. The bond strength between the layers of thin walls manufactured through FDM was evaluated through tensile testing. To measure the effect of modified manufacturing speeds, wall thicknesses were varied through the flow rate and nozzle speed. Honeycomb cores using FDM were produced with different toolpaths, and compared with an example of an industry standard Nomex honeycomb core. During tensile testing, thick-walled FDM components exhibited a more ductile failure with a lower yield point when compared to thinner specimens. The ultimate tensile stress remained constant across samples within each of the tested ABS and PLA polymers used. Honeycomb cores produced using FDM were found to have a higher compressive failure force than Nomex honeycomb, and a lower specific strength. The force–displacement curves of compressive failure show a ductile response for thick specimens, consistent with the previous result. These results, combined with the increased flexibility of additive manufacture technologies, could provide a method of manufacturing high strength cores with complex geometry

    Influence of asymmetry and nodal planes on high-harmonic generation in heteronuclear molecules

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    The relation between high-harmonic spectra and the geometry of the molecular orbitals in position and momentum space is investigated. In particular we choose two isoelectronic pairs of homonuclear and heteronuclear molecules, such that the highest occupied molecular orbital of the former exhibit at least one nodal plane. The imprint of such planes is a strong suppression in the harmonic spectra, for particular alignment angles. We are able to identify two distinct types of nodal planes. If the nodal planes are determined by the atomic wavefunctions only, the angle for which the yield is suppressed will remain the same for both types of molecules. In contrast, if they are determined by the linear combination of atomic orbitals at different centers in the molecule, there will be a shift in the angle at which the suppression occurs for the heteronuclear molecules, with regard to their homonuclear counterpart. This shows that, in principle, molecular imaging, which uses the homonuclear molecule as a reference and enables one to observe the wavefunction distortions in its heteronuclear counterpart, is possible.Comment: 14 pages, 7 figures. Figs. 3, 5 and 6 have been simplified in order to comply with the arXiv size requirement

    Sperm: seminal fluid interactions and the adjustment of sperm quality in relation to female attractiveness

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    An important predictor of male fitness is the fertilizing efficiency of their ejaculates. Ejaculates are costly to produce and males are predicted to devote greater resources to copulations with reproductively superior females. It is well established that males allocate different numbers of sperm to ejaculates. However, less is known about how males adjust their sperm quality, which has important implications for our understanding of fertilization and the evolution of sexual strategies. Here we test in the fowl, Gallus gallus, whether males adjust their sperm velocity by differentially allocating seminal fluid to copulations with attractive and unattractive females. To disentangle the contributions of sperm and seminal fluid to sperm velocity, we separated and remixed sperm and seminal fluid from ejaculates allocated to females of different attractiveness. We show that dominant males increase the velocity of the sperm they invest in more attractive females by allocating larger ejaculates that contain seminal fluid that increases sperm velocity. Furthermore, we find weak evidence that males also allocate sperm with higher velocity, irrespective of seminal fluid, to more attractive females

    Single source three dimensional capture of full field plate vibrations

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    Measurement of the vibrations of plates can offer significant challenges to the experimentalist, particularly when the plates are lightweight, exhibit large amplitude deflections, nonlinear responses or are initially curved. The use of accelerometers adds masses which can change the dynamics of lightweight plates. Large amplitude oscillations and initial curvatures cause complications when using a laser vibrometer, as they make it difficult to get consistent reflections back to the receiver. Furthermore, large or nonlinear oscillations challenge inherent assumptions on which the vibrometer’s algorithms depend. A high speed video camera avoids these issues, but makes it hard to extract numerical data. This paper describes a method that extends the capabilities of a high speed video camera by using a mirror, allowing post-processing software to stereoscopically resolve an array of points on the plate surface to 3D coordinates, capturing the complete shape and position of the plate throughout vibration. This method avoids all the problems mentioned above and gives very clear insight into plate vibration. Some example results of this method are presented, using thermally bistable carbon laminate plates filmed at a 1000 frames per second. These plates pose the challenges described, and also exhibit an unusual oscillatory motion where the plates ‘snap’ between two statically stable states. The method is shown to provide clear insight into the rich dynamics of these plates

    Genome editing to the rescue: sustainably feeding 10 billion global human population

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    Modern animal breeding strategies based on population genetics, molecular tools, artificial insemination, embryo transfer and related technologies have contributed to significant increases in the performance of domestic animals, and are the basis for a regular supply of high quality animal derived food at acceptable prices. However, the current strategy of marker- assisted selection and breeding of animals to introduce novel traits over multiple generations is too pedestrian in responding to unprecedented challenges such as climate change, global pandemics, and feeding an anticipated 33% increase in global population in the next three decades. Here, we propose site-specific genome editing technologies as a basis for “directed” or “rational selection” of agricultural traits. The animal science community envisions genome editing as an essential tool in addressing critical priorities for global food security and environmental sustainability, and seeks additional funding support for development and implementation of these technologies for maximum societal benefit

    Interspecific Germline Transmission of Cultured Primordial Germ Cells

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    In birds, the primordial germ cell (PGC) lineage separates from the soma within 24 h following fertilization. Here we show that the endogenous population of about 200 PGCs from a single chicken embryo can be expanded one million fold in culture. When cultured PGCs are injected into a xenogeneic embryo at an equivalent stage of development, they colonize the testis. At sexual maturity, these donor PGCs undergo spermatogenesis in the xenogeneic host and become functional sperm. Insemination of semen from the xenogeneic host into females from the donor species produces normal offspring from the donor species. In our model system, the donor species is chicken (Gallus domesticus) and the recipient species is guinea fowl (Numida meleagris), a member of a different avian family, suggesting that the mechanisms controlling proliferation of the germline are highly conserved within birds. From a pragmatic perspective, these data are the basis of a novel strategy to produce endangered species of birds using domesticated hosts that are both tractable and fecund
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