718 research outputs found
Computation Research
Contains report on one research project.Joint Services Electronics Programs (U.S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E
Computation Research
Contains reports on three research projects.Joint Services Electronics Programs (U.S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E
Investigating the relationship between cholinergic system integrity and Parkinsonâs disease symptoms using MRI and EEG
Cholinergic cells of the basal forebrain (cBF) and pedunculopontine nucleus (PPN) are implicated in Parkinsonâs disease (PD), but current understanding of their role in PD symptomology is limited. Neuropathological and recent in vivo imaging research implies that cBF and PPN degeneration is associated with PD cognitive and mobility impairments. There remains a need to identify and validate widely accessible markers of cholinergic system degeneration to better understand its contribution to these symptoms. The aim of this thesis was to investigate how structural changes in the cBF and PPN relate to cortical activity and cognitive and mobility performance in people with PD, people with mild cognitive impairment (MCI), and healthy age-matched controls.
T1 and diffusion-weighted images were used in combination with stereotactic maps of the cBF and PPN to extract volumetric and diffusivity metrics from these regions as in vivo surrogate markers of structural integrity. These structural measures were assessed for their relationship with resting-state EEG, and cognitive and functional mobility performance.
People with PD showed reduced cBF volumes compared to healthy controls, and elevated PPN diffusivity compared to people with MCI. Subregional cBF volumes correlated with EEG changes in the theta-alpha range in people with PD and people with MCI. Volume loss in the cBF was also shown to mediate the relationship between executive function and Timed Up and Go dual-task performance in people with PD. PPN diffusivity metrics demonstrated correlations with cognitive performance and EEG changes in the alpha range in people with PD, and in the beta-gamma range in people with MCI.
Cortical activity measured with EEG may hold physiological relevance for structural changes occurring in the cBF and PPN. Volumetric loss in the cBF may impair the attentional-executive control of mobility functions. Elevated PPN diffusivity may impair attentional performance during tasks that require sensorimotor integration
Computation Research
Contains reports on four research projects.Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E
Response to Kamath et al 'A syncretic approach can yield dividends'
We welcome the response from Kamath et al. and their insight into the issues and culture within medicine in India, and their thoughts about how to address these issues. We also agree that a drama-based approach is not sufficient on its own to deal with entrenched power issues which affect students adversely. As we have indicated, we believe âa multipronged approach is needed to generate systemic change.â These authors similarly advocate that student mistreatment be dealt with âin a comprehensive mannerâ including a âgrievance redressal systemâ and other measures to withhold accreditation where there are issues of abuse of power. Nevertheless, we note that Kamath et al. have responded positively to our approachâas a part of that mixâand it would be of great interest to see whether drama-based workshops could support medical students developing embodied acting skills in their institution and whether they may have similar transformative effects. Weâd like to refer the authors to an excellent Medical Humanities paper we referenced that outlined drama-based activities in medical education in India: Gupta S, Singh S. Confluence: understanding medical humanities through street theatre. Medical Humanities. 2011;37(2):127-128. Despite the above article, the authors note that medical education in India has not embraced the medical humanities. We would draw a distinction within the medical humanities between activities which are primarily studious (reading literature, studying medical history) and workshops that are based on participative and embodied activity. Our experience has indicated the effectiveness of drama-based workshops in addressing both the cognitive and emotive aspects of harmful practices and we believe that it is the embodied nature of acting skills workshops that is transformative
Speech Communication
Contains research objectives and reports on three research projects.U. S. Air Force (Electronic Systems Division) under Contract AF19(628)-5661National Institutes of Health (Grant 5 RO1 NB-04332-04
Test Results Using A Bell Jar To Measure Containment Vessel Pressurization
ABSTRACT A bell jar is used to determine containment vessel pressurization due to outgassing of plutonium materials. Fifteen food cans containing plutonium bearing materials, including plutonium packaged in direct contact with plastic and plutonium contaminated enriched uranium oxide have been tested to date. As expected, minimal pressurization occurs and in some cases a slight depressurization has been observed. Linear extrapolation of the greatest pressurization observed in the bell jar to a typical drum shipping container (such as a 9975) has been performed. Pressurization from this particular can packaged for one year in a 9975 container is negligible
Office-based optical coherence tomographic imaging of human vocal cords
Optical coherence tomography (OCT) is an evolving noninvasive imaging modality and has been used to image the larynx during surgical endoscopy. The design of an OCT sampling device capable of capturing images of the human larynx during a typical office based laryngoscopy examination is discussed. Both patientâs and physician\u27s movements were addressed. In vivo OCT imaging of the human larynx is demonstrated. Though the long focal length limits the lateral resolution of the image, the basement membrane can still be readily distinguished. Office-based OCT has the potential to guide surgical biopsies, direct therapy, and monitor disease. This is a promising imaging modality to study the larynx
Reevaluation of Vitrified High-Level Waste Form Criteria for Potential Cost Savings at the Defense Waste Processing Facility -13598
ABSTRACT At the Savannah River Site (SRS) the Defense Waste Processing Facility (DWPF) has been immobilizing SRS's radioactive high level waste (HLW) sludge into a durable borosilicate glass since 1996. Currently the DWPF has poured over 3,500 canisters, all of which are compliant with the U. S. Department of Energy's (DOE) Waste Acceptance Product Specifications for Vitrified High-Level Waste Forms (WAPS) and therefore ready to be shipped to a federal geologic repository for permanent disposal. Due to DOE petitioning to withdraw the Yucca Mountain License Application (LA) from the Nuclear Regulatory Commission (NRC) in 2010 and thus no clear disposal path for SRS canistered waste forms, there are opportunities for cost savings with future canister production at DWPF and other DOE producer sites by reevaluating high-level waste form requirements and compliance strategies and reducing/eliminating those that will not negatively impact the quality of the canistered waste form
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