1,060 research outputs found
Age-Specific 18F-FDG Image Processing Pipelines and Analysis Are Essential for Individual Mapping of Seizure Foci in Paediatric Patients with Intractable Epilepsy
Fluoro-18-deoxyglucose positron emission tomography (FDG-PET) is an important tool for the pre-surgical assessment of children with drug-resistant epilepsy. Standard assessment is carried out visually and this is often subjective and highly user-dependent. Voxel-wise statistics can be used to remove user-dependent biases by automatically identifying areas of significant hypo/hyper-metabolism, associated to the epileptogenic area. In the clinical settings, this analysis is carried out using commercially available software. These software packages suffer from two main limitations when applied to paediatric PET data: 1) paediatric scans are spatially normalised to an adult standard template and 2) statistical comparisons use an adult control dataset. The aim of this work is to provide a reliable observer-independent pipeline for the analysis of paediatric FDG-PET scans, as part of pre-surgical planning in epilepsy. METHODS: A pseudo-control dataset (n = 19 for 6-9y, n = 93 for 10-20y) was used to create two age-specific FDG-PET paediatric templates in standard paediatric space. The FDG-PET scans of 46 epilepsy patients (n = 16 for 6-9y, n = 30 for 10-17y) were retrospectively collated and analysed using voxel-wise statistics. This was implemented with the standard pipeline available in the commercial software Scenium and an in-house Statistical Parametric Mapping v.8 (SPM8) pipeline (including age-specific paediatric templates and normal database). A kappa test was used to assess the level of agreement between findings of voxel-wise analyses and the clinical diagnosis of each patient. The SPM8 pipeline was further validated using post-surgical seizure-free patients. RESULTS: Improved agreement with the clinical diagnosis was reported using SPM8, in terms of focus localisation, especially for the younger patient group: kScenium=0.489 versus kSPM=0.805. The proposed pipeline also showed a sensitivity of ~70% in both age ranges, for the localisation of hypo-metabolic areas on paediatric FDG-PET scans in post-surgical seizure-free patients. CONCLUSION: We show that by creating age-specific templates and using paediatric control databases, our pipeline provides an accurate and sensitive semi-quantitative method for assessing FDG-PET scans of patients under 18y
Measurement of the impact of Winona Health Online
The purpose of this article is to present the methodology to study the clinical and financial outcomes associated with the use of Winona Health Online, a novel community-wide interactive healthcare Website in Winona, Minnesota. Outcome methodology was developed by the University of Minnesota School of Public Health and the Carlson School of Management in cooperation with nationally recognized outcomes and disease state management experts, healthcare practitioners in Winona, statisticians, and health economists. The main areas of measurement include health status, satisfaction, cost and utilization of services, and clinical quality
Early bearing fault analysis using high frequency enveloping techniques
High frequency acceleration enveloping is one of many tools that vibration analysts have at their disposal for the diagnosis of bearing faults in rotating machinery. This technique is believed to facilitate very early detection of potential failures by detecting low amplitude repetitive impacts in frequency ranges above conventional condition monitoring. One traditional enveloping method uses a mathematical operation known as the Hilbert transform along with other signal processing procedures such as band-pass filtering and full-wave rectification. For comparison, another method uses a proprietary algorithm included in National Instruments’ LabVIEWTM add-on package: Sound and Measurement Suite. Enveloping’s inherent problem with noise introduction is also addressed herein. A controlled, three-stage fault was induced and diagnosed utilizing both acceleration enveloping methods and traditional fast Fourier transformation (FFT) described herein. A performance assessment of the enveloping process with respect to FFT as well as the performance between individual enveloping methods is presented. In summary, several high frequency acceleration enveloping methods exist that can be effective tools in detection of bearing faults earlier than FFT alone
Styrene-Maleic Anhydride and Styrene-Ma1eimide Based Copolymers as Building Blocks in Microencapsulation Procedures
This thesis addresses the formation and properties of capsule walls formed from new types of wall-former materials such as styrene-maleic anhydride and styrenemaleimide based preformed hydrophobic polymers. During the course of this study two new methods of encapsulation were developed: interfacial encapsulation based on the cross-linking reaction between oil-soluble styrene-maleic anhydride (SMA) copolymer and a water-soluble polyamine, or alternatively the hydrolysis reaction of tertbutyl styrene-maleic anhydride copolymers to produce non-cross-linked microcapsules, and photoinduced phase-separation encapsulation. The internal morphologies of the produced SMA microcapsules were found to depend primarily upon polymer/core-solvent interactions and rate of amine addition. Thus, the transition from matrix structures to hollow particles was observed with increasing volume fraction of hydrophobic non-solvent, dodecyl acetate, or alternatively by slowing the rate of polyamine addition. The effect of polymer loading, type of polymer and polyamine, and molecular weight of the preformed polymer on the observed morphologies was also investigated. The interfacial reaction between styrene-maleic anhydride type of copolymers and polyamines was shown to be fast in order of minutes. Hydrolysis, as the side reaction, was not found to play a significant role in the interfacial encapsulation reaction between SMA copolymers and amines. Styrene-maleimide based capsules were prepared by photo stimulated precipitation of azobenzene-functionalized copolymers dissolved in an oil phase and dispersed in a continuous phase. This microencapsulation process was found to be irreversible, and the resulting microcapsule walls were permanent even during storage in the dark, or irradiation with visible light.Doctor of Philosophy (PhD
Measuring co-authorship and networking-adjusted scientific impact
Appraisal of the scientific impact of researchers, teams and institutions
with productivity and citation metrics has major repercussions. Funding and
promotion of individuals and survival of teams and institutions depend on
publications and citations. In this competitive environment, the number of
authors per paper is increasing and apparently some co-authors don't satisfy
authorship criteria. Listing of individual contributions is still sporadic and
also open to manipulation. Metrics are needed to measure the networking
intensity for a single scientist or group of scientists accounting for patterns
of co-authorship. Here, I define I1 for a single scientist as the number of
authors who appear in at least I1 papers of the specific scientist. For a group
of scientists or institution, In is defined as the number of authors who appear
in at least In papers that bear the affiliation of the group or institution. I1
depends on the number of papers authored Np. The power exponent R of the
relationship between I1 and Np categorizes scientists as solitary (R>2.5),
nuclear (R=2.25-2.5), networked (R=2-2.25), extensively networked (R=1.75-2) or
collaborators (R<1.75). R may be used to adjust for co-authorship networking
the citation impact of a scientist. In similarly provides a simple measure of
the effective networking size to adjust the citation impact of groups or
institutions. Empirical data are provided for single scientists and
institutions for the proposed metrics. Cautious adoption of adjustments for
co-authorship and networking in scientific appraisals may offer incentives for
more accountable co-authorship behaviour in published articles.Comment: 25 pages, 5 figure
Joint Tenancy—Creditor-Debtor Relations
By Initiative No. 208, adopted and now codified as RCW 64.28, the former prohibition against joint tenancy with the right of survivorship has been repealed and substituted with .... a form of co-ownership of property, real and personal, known as joint tenancy. \u27 The proviso that the transfer shall not derogate from the rights of creditors raises serious questions of meaning and interpretation. If the proviso means that the rights of creditors will not be changed by joint tenancy ownership, then this article will serve little purpose. If the proviso is to be applied only to the creditors existing at the time of the creation of the joint tenancy, then all subsequent creditors must look to the common law for their rights and remedies. If the proviso applies only to the original transfer creating the joint tenancy, an existing creditor may ignore the transfer and treat the debtor as the sole owner, but if the proviso be given a broader interpretation to permit its application to the passage of title occurring at the death of a joint tenant, it will create creditors\u27 rights and incidents of joint tenancy beyond the incidents at common law.8 RCW 64.28.010 further provides, ... a joint tenancy shall have the incidents of survivorship and severability as at common law. The better approach would be to limit the proviso to the original transfer, though the matter will not be laid to rest until the supreme court has passed upon this specific point
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