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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
721

Magnetic domain walls in highly anisotropic metals

Stathopoulos, Eustathios. January 1975 (has links)
No description available.
722

Intraspecific Phylogeography of Cycladenia humilis (Apocynaceae)

Last, Mariana P. 10 November 2009 (has links) (PDF)
Cycladenia humilis (Apocynaceae) is a rare perennial herb native to western North America and has a fragmented distribution in California, Utah, and Arizona. Populations in Utah and Arizona are federally listed as threatened, while there is no conservation status applied to California populations. Using genetic (three chloroplast and two nuclear DNA loci) and morphological characters, intraspecific variation between populations of C. humilis and current taxonomic conventions were assessed. Nested Clade Phylogeographic Analysis and Bayesian phylogenies were used to assess patterns within C. humilis and supported three main population groupings: a northern California, southern California, and Colorado Plateau group. The northern California populations represent a distinct group and include populations from the Santa Lucia Mountains contrary to current classifications. The southern California group consistently includes populations in the San Gabriel and Inyo Mountains and was unique from any other region. The Colorado Plateau represents a group distinct from all other groups. The resilience of C. humilis on the Colorado Plateau to human threats remains unknown, but based on its frequency being comparable to California and our findings that considerable genetic variation exists within the species and within populations on the Colorado Plateau, we recommend that the threatened status of C. humilis be lifted.
723

Atypical Presentation of Cerebral Palsy and Seizures: A Case Report on Rasmussen's Encephalitis in an Adolescent

Noordin, Naveed S., Deyo, Logan J., Ryon, Connor W., Anderson, Willie T. 04 March 2021 (has links)
Rasmussen's encephalitis is a rare neurological disease first described in 1958 that is characterized by medico-refractory seizures, focal unilateral cerebral inflammation, and deficits such as hemiparesis. While we still do not have a full understanding of this disease, proposed theories behind its etiology include auto-immune manifestations, immune attack by T cells, and malfunctional alterations in genetic expression. It is classically considered a rare childhood malady with a median age of onset of six years, and cases in adolescents and adults are even rarer, representing up to 10% of all cases to date. In this report, we would like to share a rare case of Rasmussen's encephalitis that occurred in an adolescent. Our 17-year-old male patient presented with signs and symptoms beginning at age 14 and was initially diagnosed with cerebral palsy only to later present with additional symptoms and characteristic EEG and MRI findings that ultimately led to a diagnosis of Rasmussen's encephalitis. Thus, with this case report, our intent is twofold: to shed light on an atypical presentation of an already rare disease, even rarer in adolescents and adults, and to underscore the importance of keeping a broad differential when it comes to evaluating a patient with seizures.
724

Evidence synthesis for guideline development of a rare disease — chronic hypoparathyroidism

Yao, Liang January 2023 (has links)
Rare diseases currently impact over 250 million people worldwide, accounting for over 3.5% of the global population. Clinicians caring for individuals living with rare diseases face difficulties providing accurate diagnosis and effective treatments. The low prevalence of individual rare diseases, and limited data and constrained resources available for research, makes it challenging to develop useful clinical guidelines. The objective of this thesis is to share our experience in conducting evidence synthesis for the guideline development of a rare disease—chronic hypoparathyroidism, and show how we addressed the challenges encountered during the review process. The thesis begins by describing the challenges of evidence synthesis for guideline development in the context of rare diseases. I then present our strategies to overcome these challenges in three systematic reviews prepared for a chronic hypoparathyroidism guideline. The thesis ends by summarizing the challenges and solutions, highlighting strengths and limitations, and describing opportunities and challenges for future research in evidence synthesis for rare diseases. / Thesis / Candidate in Philosophy
725

New Methodologies for the Characterization and Separation of Rare Earth Elements Present in Coal

Kiser, Michael James 24 November 2015 (has links)
Three phases of work were performed for this study. First a new form of liberation analysis was created and applied to two coal samples from separate formations. This new method of liberation analysis attempts to remove sources of error found in the traditional form of liberation analysis. This new method is capable of producing results comparable to multiple iterations of the traditional liberation analysis while using only one head sample. The new method relies on the mathematical reconstruction of the data to produce the resulting liberation profile. This allows the user to easily expand the method to include more liberation profiles without greatly increasing the amount of head weight needed. The results of this phase confirm that the products of each liberation profile reconstitute the correct feed ash. The second phase of work focused on the evaluation and concentration of rare earth elements (REEs) present in the refuse streams of coal processing plants found in the eastern United States. Twenty plants were sampled for the fleet study. Samples of these plants' refuse streams were collected and their REE and ash contents were determined. Coal from the Eagle seam, Fire Clay seam, and Fire Clay Rider were collected and tested during the concentration phase. Samples of a waste coal from the Pittsburgh seam and a coal combustion by prodcut were also provided by a third party. The separation methods investigated include multi-gravity separation, electrostatic separation, and selective oil agglomeration. Partition curves from x-ray sorting devices were also applied to REE float-sink data as well. The results of this work show that REEs tend to partition with low ash material when viewing the results on an ash basis. Finally, the third phase of this work involved the application of x-ray sorting technology on different coals. This work showed that the x-ray sorting technology in question is capable of effectively treating prescreened feed with a size range of 2" x 1/4". The work also shows that the x-ray sorting technology also has applications in the power generation field, where it can be used to eliminate elements of environmental concern. / Ph. D.
726

Rare Decays in BaBar: Search for Decays of the Neutral B Meson into Two Leptons and Measurement of CP Asymmetry in Inclusive Radiative Decays of the B Meson into a Strange-quark System

Salvati, Emmanuele 01 February 2010 (has links)
No description available.
727

Some Thermodynamic Properties of Rare Earth Thiofluoride and Caβ"-Alumina Compounds

Koch, Mark 04 1900 (has links)
Abstract Specifics included in thesis. / Thesis / Master of Engineering (MEngr)
728

Perturbed Angular Correlation Studies in the Ferromagnetic Rare Earths

McMath, Thompson Andrew 10 1900 (has links)
<p> A low temperature apparatus has been constructed for the purpose of studying perturbed angular correlations in the ferromagnetic rare earth elements. The rotation of the 966.4 keV gamma vibrational state in 160Dy was measured to be (1.61 ± 0.33) milliradians.</p> / Thesis / Master of Science (MSc)
729

Polynuclear Rare-earth (RE) based Metal-Organic Frameworks (MOFs): From Topological Exploration to Preparation of Tailor-made MOFs

Assen, Ayalew H. 09 1900 (has links)
Metal-organic frameworks (MOFs) have emerged as a unique class of solid-state materials, exemplifying the power of combining organic and inorganic chemistries to address the enduring challenge pertaining to designing solid state materials with desired attributes. Notably, a myriad of MOFs were constructed in the last two decades. In particular, the use of well-defined polyatomic clusters as molecular building blocks (MBBs) permitted access to the looked-for geometrical features, incorporated in preselected building units prior to the assembly process, guiding the assembly of a targeted network. Nevertheless, the diverse coordination modes and geometries of rareearth (RE) elements requires the introduction of a sophisticated controlled approach for their use as polynuclear cluster MBBs. Subsequently, our group has introduced the use of 2-fluorobenzoic acid (2-FBA) modulator that consistently allows the in situ control and formation of multi-nuclear RE MBBs. The presented work in this thesis demonstrates the use of elaborate RE MBBs and their successful deployment in reticular chemistry for the construction of particular MOF platforms expressing unique properties in term of gas separations. Accordingly, the RE hexanuclear clusters were used to construct fcu- and fluMOF platforms with controlled pore-aperture sizes. Markedly, the isolated RE-MOFs, REfum-fcu-MOF and RE-bqdc-flu-MOF, showed unprecedented paraffin/isoparaffin molecular sieving. Further tuning of the windows of RE-fcu-MOFs afforded the assembly of a MOF suitable for propylene/propane separation. The exceptional thermal and chemical stability and high adsorption selectivity of some of these MOFs prompted us to explore the fcu-MOF platform for selective removal of H2S/CO2 from CH4 and for sensing of toxic gases, namely H2S and NH3. Additionally, the research presented in this dissertation highlights the topological exploration for the formation of new MOFs: i) highly-connected polyatomic RE-MOFs in combination with tetrahedrally oriented tetracarboxylate ligands afforded the formation MOFs with new underlying topologies, namely kna-, kel- and kem-MOFs; ii) mixed-metal approach (RE plus other elements) was employed to fabricate MOFs containing in situ formed metalo-linker MBBs that are difficult to be pre-assembled by organic synthesis; iii) supermolecular building layer (SBL) approach was extended from the prevalent sql to the less explored double sql layer for the rational design of pillared MOFs.
730

Perspectives and Experiences of Canadian Pediatric Rare Disease Researchers in Collaborative Research with Industry: A Mixed Methods Study

Degen, Charlena 09 January 2024 (has links)
Objectives: We investigated pediatric rare disease researchers’ experiences and perspectives with research collaborations involving industry partners. Methods: This mixed methods study included a cross-sectional survey of academic/hospital-based Canadian pediatric rare disease researchers which informed semi-structured interviews with a subsample of survey participants. We analyzed survey data descriptively and interview data thematically, integrating findings narratively. Results: Of 126 survey respondents, 59 (47%) reported research collaborations with industry; we interviewed 10 of these researchers. Important benefits to collaborations with industry reported by survey participants and interviewees included access to funding and resources, while disadvantages stemmed from perceptions that partners had different motivations. Interviewees provided advice for future researchers including careful selection of an industry partner, relationship building, clear expectations, and utilizing supportive institutional structures. Conclusion: Our findings provide insights into the experiences of pediatric rare disease researchers and offer suggestions on how to conduct successful collaborative research with industry.

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