261 research outputs found

    Behavioral and Quantitative Electroencephalogram Alterations During the Whisker Nuisance Task Following Mild Traumatic Brain Injury in Mice

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    Mild traumatic brain injury (mild TBI) has been shown to cause an array of symptoms in individuals lasting up to several years. Several publications have lead researchers to believe that parvalbumin axotomy and its associated changes with gamma oscillations may be the driving force for these symptoms. Several publications have demonstrated alterations in both resting gamma and evoked gamma by way of parvalbumin dysfunction. Our research analyzed resting and evoked gamma obtained by electroencephalograms (EEG) in nine mild TBI mice and six SHAM mice by utilizing a behavioral test known as the Whisker Nuisance Task (WNT). The central fluid percussion model was used to ensure only mild injuries were being produced and has demonstrated as much as 10% of parvalbumin axotomy. Through the use of several statistical analyses, our data revealed no changes in resting state EEG spectra of injured mice, however; higher frequency ranges of gamma revealed a decrease in power during WNT testing at week one. Our data also displayed an increase in WNT scores of injured mice at week one, which persisted at week four. While our resting gamma results revealed data that is inconsistent with previous publications, it is important to note that our evoked gamma is consistent with several other papers. In order to solidify the relationship between evoked gamma and abnormal responses to the WNT, several future experiments will be considered. Experiments such as changing the placement of EEG devices, recording at specific time points rather than a range of 30 minutes, and utilizing cfos staining to determine the level of neuronal activity will help clarify that relationship of evoked gamma and abnormal WNT scores

    Gaseous Electronics

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    Contains reports on one research project.Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DAAB07-71-C-030

    Design framework for multifunctional additive manufacturing: coupled optimization strategy for structures with embedded functional systems

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    The driver for this research is the development of multi-material additive manufacturing processes that provide the potential for multi-functional parts to be manufactured in a single operation. In order to exploit the potential benefits of this emergent technology, new design, analysis and optimization methods are needed. This paper presents a method that enables in the optimization of a multifunctional part by coupling both the system and structural design aspects. This is achieved by incorporating the effects of a system, comprised of a number of connected functional components, on the structural response of a part within a structural topology optimization procedure. The potential of the proposed method is demonstrated by performing a coupled optimization on a cantilever plate with integrated components and circuitry. The results demonstrate that the method is capable of designing an optimized multifunctional part in which both the structural and system requirements are considered

    A novel approach to design lesion-specific stents for minimum recoil

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    Stent geometries are obtained by topology optimization for minimized compliance under different stenosis levels and plaque material types. Three levels of stenosis by cross-sectional area, i.e., 30%, 40%, and 50% and three different plaque material properties, i.e., calcified, cellular, and hypocellular, were studied. The raw optimization results were converted to clear design concepts and their performance was evaluated by implanting them in their respective stenosed artery types using finite element analysis. The results were compared with a generic stent in similar arteries, which showed that the new designs showed less recoil. This work provides a concept that stents could be tailored to specific lesions in order to minimize recoil and maintain a patent lumen in stenotic arteries

    Adapting Cohort-Component Methods to a Microsimulation: A case study

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    Social scientists generally take United Nations (UN) population projections as the baseline when considering the potential impact of any changes that could affect fertility, mortality or migration, and the UN typically does projections using the cohort-component method (CCM). The CCM technique is computationally simple and familiar to demographers. However, in order to avoid the exponential expansion of complexity as new dimensions of individual difference are added to projections, and to understand the sensitivity of projections to specific conditions, agent-based microsimulations are a better option. CCMs can mask hidden assumptions that are surfaced by the construction of microsimulations, and varying such assumptions can lead to quite different projections. CCM models are naturally the strongest form of validation for population projection microsimulations but there are many complexities and difficulties associated with matching microsimulation projections and CCM projections. Here, we describe our efforts to tackle these challenges as we validated a microsimulation for Norway by replicating a UN CCM projection. This provides guidance for other simulationists who seek to use CCMs to validate microsimulations. More importantly, it demonstrates the value of microsimulations for surfacing assumptions that frequently lie hidden, and thus unevaluated, within CCM projections.publishedVersio

    Adapting Cohort-Component Methods to a Microsimulation: A case study

    Get PDF
    Social scientists generally take United Nations (UN) population projections as the baseline when considering the potential impact of any changes that could affect fertility, mortality or migration, and the UN typically does projections using the cohort-component method (CCM). The CCM technique is computationally simple and familiar to demographers. However, in order to avoid the exponential expansion of complexity as new dimensions of individual difference are added to projections, and to understand the sensitivity of projections to specific conditions, agent-based microsimulations are a better option. CCMs can mask hidden assumptions that are surfaced by the construction of microsimulations, and varying such assumptions can lead to quite different projections. CCM models are naturally the strongest form of validation for population projection microsimulations but there are many complexities and difficulties associated with matching microsimulation projections and CCM projections. Here, we describe our efforts to tackle these challenges as we validated a microsimulation for Norway by replicating a UN CCM projection. This provides guidance for other simulationists who seek to use CCMs to validate microsimulations. More importantly, it demonstrates the value of microsimulations for surfacing assumptions that frequently lie hidden, and thus unevaluated, within CCM projections.publishedVersio

    A proposed framework for point of care musculoskeletal ultrasound and ultrasound image-guided interventions by physiotherapists: scope of practice, education and governance

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    Background: The use of point of care ultrasound (PoCUS) in the management of musculoskeletal (MSK) disorders is a diverse area of PoCUS practice. Its use by clinicians, such as physiotherapists, can occur across a wide range of roles and care pathway configurations; however, professional, educational and regulatory uncertainties can leave clinicians, managers and patients at risk. Main body: A PoCUS framework approach (previously applied to support PoCUS consolidation and expansion) is used to frame these proposals. Central to this is the defining of (clinical and sonographic) scope of practice (ScoP). A number of indicative ScoPs are described to both (i) illustrate application of the principles and (ii) provide templates for ScoP derivations for individual services or clinicians. Image-guided MSK interventions are increasingly an aspect of MSK physiotherapy PoCUS. Given the utility of physiotherapists drawing upon their imaging to fully inform the selection (and performance) of such techniques, we present a rationale for competency in undertaking sonographic differentials as a pre-cursor to performing ultrasound image-guided MSK interventions. Alignment of ScoP with the relevant education and formal competency assessments are a cornerstone of the PoCUS framework approach; as such, key aspects of MSK PoCUS education and competency assessment are outlined. Strategies for addressing such requirements in healthcare settings where formal provision is not accessible, are also presented. Governance considerations are aligned with the regulatory environment, including those pertaining to professional guidance and insurance considerations. In addition, generic quality assurance elements are emphasised, as core aspects of high-quality service provision. Whilst the paper clarifies the situation for MSK physiotherapists using PoCUS in the UK, prompts are provided to support other professional groups working in MSK services in the United Kingdom (UK) and MSK physiotherapists/physical therapists in other countries—to facilitate their application of the principles. Conclusion: Acknowledging the breadth of MSK physiotherapy PoCUS practice, this paper draws upon a framework approach to provide integrated ScoP, education/competency and governance solutions, along with mechanisms for other professions working with MSK PoCUS—and physiotherapists/physical therapists outside of the UK—to consolidate and expand their practice
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