1,687 research outputs found

    Application of Confocal Laser Scanning Microscopy to Cytocompatibility Testing of Potential Orthopaedic Materials in Immortalised Osteoblast-Like Cell Lines

    Get PDF
    Confocal laser scanning microscopy (CLSM) was used in conjunction with in vitro cell culture to investigate cellular interactions with orthopaedic biomaterials. Transfected rat and human osteoblasts were seeded on two potential isoelastic hip prosthesis materials, carbon fibre reinforced polyetheretherketone (PEEK) and epoxy. Titanium 318 alloy was employed as a control. Determination of the material surface contour, an important factor influencing cellular adhesion, proliferation and function, was performed using the industry standard Talysurf® and compared to analogous results obtained using the CLSM. The latter technique consistently gave higher values of material roughness but offers the advantage that it can be used to correlate roughness with cell distribution on the same samples, whereas Talysurf® measurement of roughness requires clean rigid samples. Image analysis and processing, performed on cells after attachment and culture on the materials for 48 hours, provided cell morphology data. Cells cultured on titanium were larger, with a higher percentage of cytoplasm, than those grown on either of the other materials. The macroscopic surface of epoxy resulted in smaller cells with altered morphology, which orientated themselves along carbon fibres. In conclusion, we believe CLSM offers great potential for investigating the cellular interactions of biomaterials involving minimal sample preparation, non-invasive optical sectioning of samples and minimal opportunity for generation of cellular deformation and sample preparation artefacts

    No Detectable Fertility Benefit from a Single Additional Mating in Wild Stalk-Eyed Flies

    Get PDF
    Background: Multiple mating by female insects is widespread, and the explanation(s) for repeated mating by females has been the subject of much discussion. Females may profit from mating multiply through direct material benefits that increase their own reproductive output, or indirect genetic benefits that increase offspring fitness. One particular direct benefit that has attracted significant attention is that of fertility assurance, as females often need to mate multiply to achieve high fertility. This hypothesis has never been tested in a wild insect population.Methodology/Principal Findings: Female Malaysian stalk-eyed flies (Teleopsis dalmanni) mate repeatedly during their lifetime, and have been shown to be sperm limited under both laboratory and field conditions. Here we ask whether receiving an additional mating alleviates sperm limitation in wild females. In our experiment one group of females received a single additional mating, while a control group received an interrupted, and therefore unsuccessful, mating. Females that received an additional mating did not lay more fertilised eggs in total, nor did they lay proportionately more fertilised eggs. Female fertility declined significantly through time, demonstrating that females were sperm limited. However, receipt of an additional mating did not significantly alter the rate of this decline.Conclusions/Significance: Our data suggest that the fertility consequences of a single additional mating were small. We discuss this effect (or lack thereof), and suggest that it is likely to be attributed to small ejaculate size, a high proportion of failed copulations, and the presence of X-linked meiotic drive in this species

    A re-appraisal of the reliability of the 20 m multi-stage shuttle run test

    Get PDF
    This is the author's PDF version of an article published in European journal of applied physiology in 2007. The original publication is available at www.springerlink.co

    Exploring the value of a cyber threat intelligence function in an organization

    Get PDF
    Organizations can struggle to cope with the rapidly advancing threat landscape. A cyber threat intelligence (CTI) function broadly aims to understand how threats operate to better protect the organization from future attacks. This seems like a natural step to take in hardening security. However, CTI is understood and experienced differently across organizations. To explore the value of this function this study used a qualitative method, guided by the Socio-Technical Framework, to understand how the CTI function is interpreted by organizations in South Africa. Thematic analysis was used to provide an in-depth view of how each organization implemented its CTI function and what benefits and challenges they’ve experienced. Findings show that CTI tasks tend to be more manual and resource-intensive, but these challenges can be resolved through automation. It was noted that only larger organizations seem to have the budget and resources available to implement the CTI function, whereas smaller organizations put more reliance on tools. It was observed that skills for the CTI function can be learned on the job, but that formal education provides a good foundation. The findings illustrate the value the CTI function can provide an organization but also the challenges, thereby enabling other organizations to improve preparation before such a function is adopted

    Building professional discourse in emerging markets: Language, context and the challenge of sensemaking

    Get PDF
    Using ethnographic evidence from the former Soviet republics, this article examines a relatively new and mainly unobserved in the International Business (IB) literature phenomenon of communication disengagement that manifests itself in many emerging markets. We link it to the deficiencies of the local professional business discourse rooted in language limitations reflecting lack of experience with the market economy. This hampers cognitive coherence between foreign and local business entities, adding to the liability of foreignness as certain instances of professional experience fail to find adequate linguistic expression, and complicates cross-cultural adjustments causing multi-national companies (MNCs) financial losses. We contribute to the IB literature by examining cross-border semantic sensemaking through a retrospectively constructed observational study. We argue that a relative inadequacy of the national professional idiom is likely to remain a feature of business environment in post-communist economies for some time and therefore should be factored into business strategies of MNCs. Consequently, we recommend including discursive hazards in the risk evaluation of international projects

    Predictors of vitamin D status and its association with parathyroid hormone in young New Zealand children.

    No full text
    BACKGROUND: Despite increased awareness of the adverse health effects of low vitamin D status, few studies have evaluated 25-hydroxyvitamin D [25(OH)D] status in young children. OBJECTIVES: We aimed to assess vitamin D status on the basis of 25(OH)D and its relation with parathyroid hormone (PTH) and to identify possible predictors of 25(OH)D status in young children living in a country with minimal vitamin D fortification. DESIGN: Serum 25(OH)D and PTH concentrations were measured in a cross-sectional sample of children aged 12-22 mo [n = 193 for 25(OH)D, n = 144 for PTH] living in Dunedin, New Zealand (latitude: 45 degrees S). Anthropometric, dietary, and sociodemographic data were collected. RESULTS: The majority of children sampled in the summer (94%; 47 of 50) had 25(OH)D >50 nmol/L; however, nearly 80% of children sampled in the winter (43 of 55) had serum concentrations 60-65 nmol/L, a plateau in PTH was evident. CONCLUSIONS: Seasonal variation in 25(OH)D concentration implies that postsummer vitamin D stores were insufficient to maintain status >50 nmol/L year-round. Examination of the predictors of 25(OH)D in our model shows few modifiable risk factors, and thus effective dietary strategies may be required if future research determines that children with 25(OH)D concentrations <50 nmol/L are at significant health risk. This trial was registered at www.actr.org.au as ACTRN12605000487617

    Using Policy Labs as a process to bring evidence closer to public policymaking: a guide to one approach

    Full text link
    While robust evidence is one ingredient in the policymaking process, it is by no means the only one. Engaging with policymakers and the policymaking process requires collaborative working models, navigating through the experiences, values and perspectives of policymakers and other stakeholders, as well as communicating evidence in an accessible manner. As a response to these requirements, over recent years there has been proliferation of activities that engage producers of evidence (specifically, academics), policymakers, practitioners, and the public in policy formulation, implementation and evaluation. In this article, we describe one engagement approach for facilitating research evidence uptake into policy and practice—an activity called a ‘Policy Lab’—as conducted by the team at The Policy Institute at King’s College London on numerous policy challenges over the past four years. Drawing on our experience in running 15 Policy Labs between January 2015 and September 2019, we (a) provide a guide to how we have run Policy Labs, while sharing our learning on what has worked best in conducting them and (b) demonstrate how these labs can contribute to bringing evidence closer to policymaking, by comparing their characteristics to enablers for doing so identified in the literature. While this approach to Policy Labs is not the only one of its kind, we suggest that these types of Labs manifest characteristics identified in previous studies for influencing the policymaking process; namely: providing a forum for open, honest conversations around a policy topic; creating new networks, collaborations and partnerships between academics and policymakers; synthesising available evidence on a policy topic in a robust and accessible format; and providing timely access to evidence relevant to a policy issue. We recognise the limitations of measuring and evaluating how these Labs change policy in the long-term and recommend viewing the Policy Lab as part of a process for engaging evidence and policymaking and not an isolated activity. This process serves to build a coalition through participation of diverse communities (thereby establishing ‘trust’), work on the language and presentation of evidence (thereby enabling effective ‘translation’ of evidence) and engage policymakers early to respond when policy windows emerge (thereby taking into account ‘timing’ for creating policy action)
    corecore