Does a PEEK femoral TKA implant preserve intact femoral surface strains compared with CoCr? A preliminary laboratory study

BACKGROUND: Both the material and geometry of a total knee arthroplasty (TKA) component influence the induced periprosthetic bone strain field. Strain, a measure of the local relative deformation in a structure, corresponds to the mechanical stimulus that governs bone remodeling and is therefore a useful in vitro biomechanical measure for assessing the response of bone to new implant designs and materials. A polyetheretherketone (PEEK) femoral implant has the potential to promote bone strains closer to that of natural bone as a result of its low elastic modulus compared with cobalt-chromium (CoCr).QUESTIONS/PURPOSES: In the present study, we used a Digital Image Correlation (DIC) technique to answer the following question: Does a PEEK TKA femoral component induce a more physiologically normal bone strain distribution than a CoCr component? To achieve this, a DIC test protocol was developed for periprosthetic bone strain assessment using an analog model; the protocol aimed to minimize errors in strain assessment through the selection of appropriate analysis parameters.METHODS: Three synthetic bone femurs were used in this experiment. One was implanted with a CoCr femoral component and one with a PEEK femoral component. The third (unimplanted) femur was intact and used as the physiological reference (control) model. All models were subjected to standing loads on the corresponding polyethylene (ultrahigh-molecular-weight polyethylene) tibial component, and speckle image data were acquired for surface strain analysis using DIC in six repeat tests. The strain in 16 regions of interest on the lateral surface of each of the implanted bone models was plotted for comparison with the corresponding strains in the intact case. A Wilcoxon signed-rank test was used to test for difference at the 5% significance level.RESULTS: Surface analog bone strain after CoCr implantation indicated strain shielding (R2 = 0.6178 with slope, ? = 0.4314) and was lower than the intact case (p = 0.014). The strain after implantation with the PEEK implant deviated less from the intact case (R2 = 0.7972 with slope ? = 0.939) with no difference (p = 0.231).CONCLUSIONS: The strain shielding observed with the contemporary CoCr implant, consistent with clinical bone mineral density change data reported by others, may be reduced by using a PEEK implant.CLINICAL RELEVANCE: This bone analog in vitro study suggests that a PEEK femoral component could transfer more physiologically normal bone strains with a potentially reduced stress shielding effect, which may improve long-term bone preservation. Additional studies including paired cadaver tests are necessary to test the hypothesis further

Development of the Fabry-Perot Spectrometer Application

Methane is a greenhouse gas with global warming effects 20 times more detrimental than carbon dioxide. Currently, only aircraft missions measure methane and do not provide continuous monitoring, This presentation will cover the Fabry-Perot spectrometer which will provide continuous monitoring of methane. It will also cover the development of the software used to extract and process the data the spectrometer collects

Interdisciplinarity and insularity in the diffusion of knowledge: an analysis of disciplinary boundaries between philosophy of science and the sciences

Two fundamentally different perspectives on knowledge diffusion dominate debates about academic disciplines. On the one hand, critics of disciplinary research and education have argued that disciplines are isolated silos, within which specialists pursue inward-looking and increasingly narrow research agendas. On the other hand, critics of the silo argument have demonstrated that researchers constantly import and export ideas across disciplinary boundaries. These perspectives have different implications for how knowledge diffuses, how intellectuals gain and lose status within their disciplines, and how intellectual reputations evolve within and across disciplines. We argue that highly general claims about the nature of disciplinary boundaries are counterproductive, and that research on the nature of specific disciplinary boundaries is more useful. To that end, this paper uses a novel publication and citation network dataset and statistical models of citation networks to test hypotheses about the boundaries between philosophy of science and 11 disciplinary clusters. Specifically, we test hypotheses about whether engaging with and being cited by scientific communities outside philosophy of science has an impact on one’s position within philosophy of science. Our results suggest that philosophers of science produce interdisciplinary scholarship, but they tend not to cite work by other philosophers when it is published in journals outside of their discipline. Furthermore, net of other factors, receiving citations from other disciplines has no meaningful impact—positive or negative—on citations within philosophy of science. We conclude by considering this evidence for simultaneous interdisciplinarity and insularity in terms of scientific trading theory and other work on disciplinary boundaries and communication

Astrobee Robot Software: A Modern Software System for Space

Astrobee is a new free-flyer robot designed to operate inside the International Space Station (ISS). Astrobee capabilities include markerless navigation, autonomous docking for recharge, perching on handrails to minimize power and modular payloads. Astrobee will operate without crew support, controlled by teleoperation, plan execution, or on-board third parties software. This paper presents the Astrobee Robot Software, a NASA Open-Source project, powering the Astrobee robot. The Astrobee Robot Software relies on a distributed architecture based on the Robot Operating System (ROS). The software runs on three interconnected smart phone class processors. We present the software approach, infrastructure required, and main software components. The Astrobee Robot Software embrace modern software practices while respecting flight constraints. The paper concludes with the lessons learned, including examples usage of the software. Several research teams are already using the Astrobee Robot Software to develop novel projects that will fly on Astrobee

Why Are Native Hawaiians Underrepresented in Hawai‘i's Older Adult Population? Exploring Social and Behavioral Factors of Longevity

Native Hawaiians comprise 24.3% of Hawai‘i's population, but only 12.6% of the state's older adults. Few published studies have compared health indicators across ethnicities for the state's older adult population or focused on disparities of Native Hawaiian elders. The current study examines data from two state surveillance programs, with attention to cause of death and social-behavioral factors relevant to elders. Findings reveal that Native Hawaiians have the largest years of productive life lost and the lowest life expectancy, when compared to the state's other major ethnic groups. Heart disease and cancer are leading causes of premature mortality. Native Hawaiian elders are more likely to report behavioral health risks such as smoking and obesity, live within/below 100–199% of the poverty level, and find cost a barrier to seeking care. Indicated is the need for affordable care across the lifespan and health services continuum. Future research might explain behavioral factors as influenced by social determinants, including historical trauma on Native Hawaiian longevity

Dynamics of antimicrobial resistance in intestinal Escherichia coli from children in community settings in South Asia and sub-Saharan Africa.

The dynamics of antimicrobial resistance (AMR) in developing countries are poorly understood, especially in community settings, due to a sparsity of data on AMR prevalence and genetics. We used a combination of phenotyping, genomics and antimicrobial usage data to investigate patterns of AMR amongst atypical enteropathogenic Escherichia coli (aEPEC) strains isolated from children younger than five years old in seven developing countries (four in sub-Saharan Africa and three in South Asia) over a three-year period. We detected high rates of AMR, with 65% of isolates displaying resistance to three or more drug classes. Whole-genome sequencing revealed a diversity of known genetic mechanisms for AMR that accounted for >95% of phenotypic resistance, with comparable rates amongst aEPEC strains associated with diarrhoea or asymptomatic carriage. Genetic determinants of AMR were associated with the geographic location of isolates, not E. coli lineage, and AMR genes were frequently co-located, potentially enabling the acquisition of multi-drug resistance in a single step. Comparison of AMR with antimicrobial usage data showed that the prevalence of resistance to fluoroquinolones and third-generation cephalosporins was correlated with usage, which was higher in South Asia than in Africa. This study provides much-needed insights into the frequency and mechanisms of AMR in intestinal E. coli in children living in community settings in developing countries

Perception and risk factors for cervical cancer among women in northern Ghana

Objective: This study assessed the perception of risk of cervical cancer and existence of risk factors for cervical cancer based on five known risk factors among women attending the Tamale Teaching Hospital in Tamale, Ghana.Methods: A consecutive sample of 300 women was interviewed using a semi structured questionnaire to inquire about risk factors and perception of risk of cervical cancer. Specific risk factors that were explored included early coitarche, multiple sexual partners, polygamous relationships, history of smoking, and having a current partner who had multiple sexual partners.Results: Sixty-one per cent of women reported that they had no personal risk for cervical cancer. 27% of respondents were in polygamous relationships, and of those, more than half didn’t think they were at an increased risk of cervical cancer. 2 women had a total of ≥ 5 sexual partners in their lifetime and neither believed they were at any risk for cervical cancer. 23% said their current partner had had at least 2 sexual partners in his lifetime, and of those, (61%) thought they were at no risk for cervical cancer. 46% of respondents reported not having any of the risk factors listed in the study. 23% of respondents reported having one risk factor while 21% had two risk factors and 11% had three or more risk factors.Conclusion: Women’s perception of personal risk for cervical cancer is lower than their actual risk based on the five behavioural risk factors assessed and a lack of knowledge of the personal factors for the diseaseFunding: This project was supported by NIH Research Training Grant #R25 TW009345 funded by the Fogarty International Centre, in partnership with several NIH Institutes (NIMH, NIGMS, NHLBI, OAR and OWH)Keywords: Cervical Cancer, Risk, Perceptions, Northern Ghan

Cohort Profile: The Australian Longitudinal Study of Ageing (ALSA)

In response to the expressed need for more sophisticated and multidisciplinary data concerning ageing of the Australian population, the Australian Longitudinal Study of Ageing (ALSA) was established some two decades ago in Adelaide, South Australia. At Baseline in 1992, 2087 participants living in the community or in residential care (ranging in age from 65 to 103 years) were interviewed in their place of residence (1031 or 49% women), including 565 couples. By 2013, 12 Waves had been completed; both face-to-face and telephone personal interviews were conducted. Data collected included self-reports of demographic details, health, depression, morbid conditions, hospitalization, gross mobility, physical performance, activities of daily living, lifestyle activities, social resources, exercise, education and income. Objective performance data for physical and cognitive function were also collected. The ALSA data are held at the Flinders Centre for Ageing Studies, Flinders University. Procedures for data access, information on collaborations, publications and other details can be found at [http://flinders.edu.au/sabs/fcas/].Australian Research Council ARC (DP0879152 and 130100428; LP669272 and 100200413

Making sense of bodily sensations: Do shared cancer narratives influence symptom appraisal?

Though new or altered bodily sensations are a common occurrence they rarely transition to biomedically defined symptoms. When they do, sensations are subject to an appraisal process that can culminate in help-seeking. The transition has particular relevance for cancer diagnoses. Studies of 'symptom appraisal' in cancer patients typically conclude that failure to regard sensations as serious or 'symptom misattribution' results in lengthier help-seeking intervals. Though multiple influences on appraisal processes are acknowledged, including the socio-cultural context, detailed description and analyses of how socio-cultural factors shape appraisal is lacking. In this paper we explore one substantial component of the sociocultural context, namely, publicly recognised shared cancer narratives, and their impact on appraisal. We undertook a secondary analysis of 24 interviews with Scottish colorectal cancer patients originally completed in 2006–2007. Our analysis showed that fear, death and severity dominated cancer narratives and were frequently restated throughout interviews. Yet, early bodily changes were often mild and vague, were commonly experienced in the context of 'feeling well' and failed to match preconceived ideas of what cancer 'feels like'. Moreover, few perceived themselves to be 'at risk' of cancer and diagnoses were characterised as 'shocking' events. Participants engaged in self-monitoring strategies and severe or painful changes prompted help-seeking. Far from misattributing symptoms, responses to bodily changes were sensible and measured; responses are particularly apt in relation to current policy rhetoric, which urges measured use of services. Our findings have resonance across healthcare settings as patients are required to negotiate a narrow and challenging space when making decisions to seek help. There is a pressing need for a more realistic approach to symptom appraisal in order to reduce help-seeking intervals. Future awareness campaigns should emphasise the importance of vague/minor bodily changes although this will necessitate discussions with health professionals on referral thresholds to achieve earlier detection