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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.
31

Sediment Dynamics of a Shallow Hypereutrophic lake: Lake Jesup, Florida, USA

Nielsen, Shauna 08 November 2011 (has links)
Improved knowledge of sediment dynamics within a lake system is important for understanding lake water quality. This research was focused on an assessment of the vertical sediment flux in Lake Jesup, a shallow (1.3 m average depth) hypereutrophic lake of central Florida. Sediment dynamics were assessed at varying time scales (daily to weekly) to understand the transport of sediments from external forces; wind, waves, precipitation and/or runoff. Four stations were selected within the lake on the basis of water depth and the thicknesses of unconsolidated (floc) and consolidated sediments. At each of these stations, a 10:1 (length to diameter) high aspect ratio trap (STHA) was deployed to collect particulate matter for a one to two week period. The water and sediment samples were collected and analyzed for total carbon (TC), total phosphorus (TP) and total nitrogen (TN). Mass accumulation rates (MAR) collected by the traps varied from 77 to 418 g m-2 d-1 over seven deployments. TN, TP and TC sediment concentrations collected by the traps were consistently higher than the sediments collected by coring the lake bottom and is most likely associated with water column biomass. A yearly nutrient budget was determined from August 2009 to August 2010 with flux calculated as 2,033,882 mt yr-1.
32

Coupling Of Hydrodynamic And Wave Models For Storm Tide Simulations: A Case Study For Hurricane Floyd (1999)

Funakoshi, Yuji 01 January 2006 (has links)
This dissertation presents the development of a two-dimensional St. Johns River model and the coupling of hydrodynamic and wave models for the simulation of storm tides. The hydrodynamic model employed for calculating tides and surges is ADCIRC-2DDI (ADvanced CIRCulation Model for Shelves, Coasts and Estuaries, Two-Dimensional Depth Integrated) developed by Luettich et al. (1992). The finite element based model solves the fully nonlinear shallow water equations in the generalized wave continuity form. Hydrodynamic applications are operated with the following forcings: 1) astronomical tides, 2) inflows from tributaries, 3) meteorological effects (winds and pressure), and 4) waves (wind-induced waves). The wave model applied for wind-induced wave simulation is the third-generation SWAN (Simulating WAves Nearshore), applicable to the estimation of wave parameters in coastal areas and estuaries. The SWAN model is governed by the wave action balance equation driven by wind, sea surface elevations and current conditions (Holthuijsen et al. 2004). The overall work is comprised of three major phases: 1) To develop a model domain that incorporates the entire East Coast of the United States, Gulf of Mexico and Caribbean Sea, while honing in on the St. Johns River area; 2) To employ output from the SWAN model with the ADCIRC model and produce a uni-directional coupling of the two models in order to investigate the effects of the wave radiation stresses; 3) To couple the ADCIRC model with the SWAN model to describe the complete interactions of the two physical processes. Model calibration and comparisons are accomplished in three steps. First, astronomical tide simulation results are calibrated with historical NOS (National Ocean Service) tide data. Second, overland and riverine flows and meteorological effects are included, and computed river levels are compared with the historical NOS water level data. Finally, the storm tides generated by Hurricane Floyd are simulated and compared with historical data. This research results in a prototype for real-time simulation of tides and waves for flash flood and river-stage forecasting efforts of the NWS Forecasting Centers that border coastal areas. The following two main conclusions are reported: 1) regardless of whether one uses uni-coupling or coupling, wind-induced waves result in an approximately 10 – 15 % higher peak storm tide level than without any coupling; and 2) the wave-current interaction described by the coupling model results in decreasing peaks and increasing troughs in the storm tide hydrograph. Two main corollary conclusions are also drawn from a 122-day hindcast for the period spanning June 1 – October 1, 2005. First, wind forcing for the St. Johns River is equal to or greater than that of astronomic tides and generally supersedes the impact of inflows, while pressure variations have a minimal impact. Secondly, water levels inside the St. Johns River depend on the wind forcings in the deep ocean; however, if one applies an elevation hydrograph boundary condition from a large-scale domain model to a local-scale domain model the results are highly accurate.
33

Analysis Of The Physical Forcing Mechanisms Influencing Salinity Transport For The Lower St. Johns River

Giardino, Derek 01 January 2009 (has links)
The focus of this thesis is the forcing mechanisms incorporated with salinity transport for the Lower St. Johns River. There are two primary analyses performed: a historical data analysis of primary forcing mechanisms to determine the importance of each individual influence, and a tidal hydrodynamics analysis for the Lower St. Johns River to determine the required tidal constituents for an accurate resynthesis. This thesis is a preliminary effort in understanding salinity transport for the Lower St. Johns River for engineering projects such as the dredging of navigation canals and freshwater withdrawal from the river. The analysis of the physical forcing mechanisms is performed by examining the impact of precipitation, tides, and wind advection on historical salinity measurements. Three 30-day periods were selected for the analysis, to correspond with representative peak, most-variable, and low-salinity periods for 1999. The analysis displays that wind advection is the dominant forcing mechanism for the movement of salinity over a 30 day duration; however all mechanisms have an impact at some level. The dominant forcing mechanism is also dependent on the period of record examined where tidal influence is vital for durations of hours to a day, while freshwater inflow has more significance over a longer period due to climatological variation. A two-dimensional finite difference numerical model is utilized to generate a one month tidal elevations and velocities simulations that incorporates geometry, nonlinear advection and quadratic bottom friction. Several combinations of tidal constituents are extracted from this modeled tidal signal to investigate which combination of tidal constituents produces an accurate tidal resynthesis for the Lower St. Johns River. The analysis displays the need for 39 total tidal harmonic constituents to accurately resynthesize the original tidal signal. Additionally, due to the nonlinear nature of shallow water, the influence of the overtides for upstream or downstream locations in the Lower St. Johns River is shown to be spatially variable for different frequencies depending on the geometry. The combination of the constituent analysis and the historical analysis provides the basis information needed for the development of an accurate salinity transport model for the Lower St. Johns River.
34

An Examination of the Validity of the Rorschach Ego Impairment Index (EII-2) Using the Johns Hopkins Precursors Study Cohort

Bombel, George 25 September 2009 (has links)
No description available.
35

Non-viral delivery of nucleic acid gene editing components to the liver and brain

Cai, Shuting Sarah January 2024 (has links)
In the growing landscape of innovative non-viral delivery vehicles, polymeric and lipid nanoparticles remain at the forefront for their versatility in encapsulating a variety of therapeutic payloads. This thesis investigates their potential for facilitating the transport of nucleic acid components into cells, with a focus on targeted delivery to the liver and brain. To achieve this, we address key considerations including the composition of the delivery vector, the nature of the therapeutic cargo, and the chosen delivery route. The challenge of targeted delivery to specific organs or cell types, i.e. hepatocytes or neurons, is addressed through rational design and development of libraries of nanoparticulate systems tailored for nucleic acid therapeutics. Although liver gene editing using non-viral systems has been extensively studied, oral delivery for liver targeting remains challenging due to the mucosal barrier. To that end, we explore intraduodenal delivery as a strategy to bypass the mucosal barrier and target the liver. Furthermore, insights from collaborative research with the Mao lab at Johns Hopkins University reveal that tuning the composition of lipid nanoparticles (LNPs) can influence their preferential targeting of specific cell types. Leveraging this, we employed an in vitro library screening and machine learning approach to identify populations of LNPs capable of preferentially transfecting hepatocytes. The efficacy of these LNPs in liver gene editing is then evaluated through “cluster-mode” screening in vivo, and therapeutic efficacy was demonstrated using a proof-of-concept in vivo model for PCSK9 and ANGPTL3 knockdown, resulting in 27% serum cholesterol knockdown. In addition to liver-targeted gene delivery, this thesis also investigates the potential of polymeric and lipid nanoparticles for delivering nucleic acid therapeutics to the brain. However, overcoming the blood-brain barrier (BBB) is crucial for systemic delivery to the brain. To circumvent the BBB, we explored two methods: intracranial injection and theranostic ultrasound (THUS)-mediated temporary opening of the BBB. While intracranial injection achieves localized gene editing, THUS offers a non-invasive approach for transient and widespread BBB opening. Utilizing the previously validated in vitro screening and machine learning approaches for chitosan-grafted bPEI (CS-PEI) and lipid nanoparticle (LNP) carriers with tunable compositions, we assessed their efficacy in systemic gene delivery to the brain, and specifically their capability in preferentially transfecting neuronal cells over hepatocytes. Subsequently, we validated their efficiency via intracranial administration using the Ai14 reporter mouse model and observed up to 20% gene editing of the targeted cross-sectional area of the brain hemisphere using the top-performing cluster. Through comprehensive investigations into both brain and liver gene delivery, this thesis aims to contribute to the advancement of non-viral nanoparticle-based gene therapy strategies for treating a range of cholestatic liver diseases and hereditary neurodegenerative diseases.
36

Description de l’évolution du savoir infirmier chez les infirmières en prévention et contrôle des infections ayant suivi un cours en microbiologie et infectiologie / Examination of the evolution of patterns of knowing in nursing in infection prevention and control among nurses who have completed a course in microbiology and infectious diseases

Gaudreau, Marie-Andrée January 2015 (has links)
Résumé : L’Ordre des infirmières et infirmiers du Québec (OIIQ) a créé en 2011 une spécialisation pour les infirmières en PCI qui doivent maintenant suivre une formation de 2e cycle pour l’obtention de leur titre d’infirmière clinicienne spécialisée en PCI. Au sein de cette formation figure un cours de microbiologie et infectiologie (MI) qui vise à parfaire les connaissances et l’expertise en la matière. Jusqu’à présent, aucune étude n’avait été réalisée pour évaluer l’influence de ce cours sur le savoir infirmier des infirmières en PCI. Cette étude vise à décrire l’évolution du savoir infirmier des infirmières en PCI qui participent au cours de MI du programme de 2e cycle en PCI. Un devis qualitatif descriptif a été utilisé au cours de cette étude pour décrire l’évolution du savoir infirmier. Le modèle de réflexion structurée (MRS) de Johns (1995) a servi à l’élaboration d’entrevues semi-dirigées individuelles avant et après le cours de MI, afin de permettre l’identification du savoir infirmier selon un processus déductif. La méthode de codification de Miles et Huberman (2003) a ensuite favorisé un processus semi-inductif. Une analyse horizontale a finalement permis de repérer les récurrences ou les changements dans le savoir infirmier entre les entrevues de chaque participante ainsi qu’entre les participantes elles-mêmes. Des manifestations des dimensions du savoir infirmier telles que définies par Johns et influencées par Carper (1978) sont décrites, ainsi que l’évolution du savoir infirmier suite à la participation au cours de MI. Les thèmes qui ont découlé des entrevues sont : le développement d’un vocabulaire favorisant la communication dans l’équipe, la capacité d’aller au-delà des protocoles, une meilleure confiance en leurs capacités et l’élargissement d’une vision éthique qui comprend tous les acteurs de la communauté. Les retombées de l’étude se retrouvent au plan de la formation par la mise en valeur de la perspective infirmière dans le cours de MI et par l’évolution du savoir infirmier après avoir suivi ce cours. Sur le plan de la recherche, cette étude présente une nouvelle approche, pour de futures recherches, permettant d’évaluer la contribution d’un cours universitaire. / Abstract : As the Ordre des infirmières et infirmiers du Québec (OIIQ) has created in 2011 a specialty, making it possible for nurses to develop their expertise in infection prevention and control (IPC). In order to become an IPC clinical nurse specialist, nurses must fulfil a graduate program, which includes a course in microbiology and infectious diseases (MID), among others. Until now, there has been no study evaluating the influence of this training or course on patterns of knowing in nursing for IPC nurses. The goal of this study was to determine the evolution of the patterns of knowing in nursing for IPC nurses who have completed an MID course as part of a graduate program in IPC. A qualitative descriptive evaluation made it possible to determine the evolution of the patterns of knowing. Johns’ model (1995) for structured reflection (MSR) which was used in semi-structured, individual interviews before and after an MID course, helped identify patterns of knowing through a deductive process. Furthermore, Miles and Huberman’s (2003) codification method ensured a semi-inductive process. A horizontal analysis allowed for the detection of recurrence or change in patterns of knowing between each participant’s interviews, as well as between participants. The illustration of the scope of the patterns of knowing in nursing, as defined by Johns and influenced by Carper (1978), as well as the evolution of the patterns of knowing after completing an MID course, were described. The topics that surfaced during the interviews were: the development of a vocabulary fostering team communication, the capacity to go beyond protocols, a greater confidence in their abilities, and the expansion of an ethical view that includes all stakeholders in the community. The benefits of the study are at the level of training and research. Training is represented by the development of nursing perspective in the MID courses and the development of nursing knowledge after completing a course in MID. Finally, towards the research, this has put forward a new approach to assess the contribution of a university course.
37

Aldo Crommelynck (1931 - 2008) : un imprimeur de gravures entre Paris et New-York / Aldo Crommelynck ( 1931 - 2008) : an etching printer between Paris and New York

Aynard, Emmanuelle 18 March 2017 (has links)
Aldo Crommelynck (1931-2008) a animé l'atelier Crommelynck à Paris de 1956 à 1986, en compagnie de son frère Piero, puis a travaillé seul entre Paris et New York en partenariat avec Pace Editions, jusqu'en 1998. Sa collaboration avec les peintres modernes, dont Picasso à Mougins, a inauguré une carrière internationale auprès d'une quarantaine d'artistes contemporains. Sa maîtrise de l'eau-forte s'est intégrée au milieu artistique international, entre Paris, Londres et New York, dans un contexte profitable au marché de l'art. Son nom est associé à un mouvement de retour à la taille­douce qui coïncide avec le goût des artistes issus du Pop pour le travail de la main et pour la figuration du quotidien. D'autres, issus du minimalisme et du néo-expressionnisme, verront en lui le dépositaire d'un certain métier de la gravure identifié à Paris. Cette thèse entend déterminer ce que fut le «style Crommelynck», dans toutes ses dimensions. / Aldo Crommelynck (1931-2008) run the Crommelynck studio, in Paris from 1956 to 1986, with his brother Piero, and then worked alone between Paris and New York in partnership with Pace Editions until 1998. His collaboration with modem painters, including Picasso in Mougins, preceded his international career with forty or so contemporary artists. His mastery of etching well integrated into the artistic world of Paris, London and New York, in a context profitable to the art market. His name is associated with the revival of printmaking in the United States that coincided with the taste of the artists coming from Pop Art for handmade creation and for the representation of daily life. Others, who came afterwards, impregnated with Minimalism or Neo-expressionism, saw him as the repository of a certain etching craft identified with Paris. This thesis intends to determine what was the « Crommerlynck style » in all its dimensions.
38

Use of Simulation for Tracheostomy Care, a Low Volume, High Risk Nursing Procedure

Ramakrishnan, Vijaya 01 January 2018 (has links)
Often, education regarding low volume and high-risk procedures, like tracheostomy, are ignored. Lack of experience, skills, and human resources can lead to decreases in confidence levels, diminished quality of care, and potentially an adverse event. The purpose of this DNP project was to prepare simulation-based education on the tracheostomy procedure and provide hands-on education to bedside nurses. The project answered the question: To what extent will a simulation-based teaching method adequately prepare staff nurses in a post-acute surgical unit to perform this high risk low volume procedure? The Johns Hopkins evidence-based model method was used to assist in translation of the practice change process. The International Nursing Association for Clinical Simulation and Learning standards were used to design simulation scenarios. Surgical acute care nurses (n = 35) including day and night shift nurses, new graduates, and experienced nurses participated. Groups of five to eight nurses participated in a two-hour simulation session at hospital simulation center. Pre- and post-surveys on confidence level data, and National League of Nursing evaluation tool data on educational practices and simulation designs were collected from all participants. Paired t-test statistics showed a significant increase in confidence level from pre to post education (p < .001). Because of the significant impact on patient care due to preventing complications and by improving nursing staff's level of confidence, the project may contribute to positive social change.
39

The Development and Failure of Historic Agricultural Communities of Utah: A Case Study of Johns Valley, Utah

Shelley, Wayne R. 01 January 1989 (has links) (PDF)
Many agricultural communities have developed in Utah since the first settlement, but many no longer exist today. Some of these early communities experienced a "boom and bust," while others struggled for several years and were eventually abandoned. Johns Valley is a good example of these historic communities, as it experienced rapid growth and times of success and prosperity, yet it struggled and was eventually abandoned. The situation in Johns Valley, from its early settlement to its demise, demonstrates the hope of the people who settled there and their efforts to make Johns Valley a productive and successful area. History also shows the growth of the area and the development of communities, with schools, churches, businesses, and other institutions - as was the case with most historic agricultural communities of Utah. Despite the hope and hard work, these agricultural communities could not overcome the environment, or other factors that led to their demise. Dry farming was the main source of economic activity in Johns Valley and farmers had to rely upon adequate precipitation for crop growth. Dry farming is a technique often practiced in drier climates where irrigation is not readily available. Such areas do not have adequate precipitation in a single year, but in consecutive years there is often sufficient moisture for crop production. The main objective in dry farming is to maintain the soil in such a way that the soil will absorb and retain as much water as possible. The primary technique of dry farming is to allow the soil to remain fallow every other year. This practice allows the soil to store up water for two years so that there will be sufficient water for one year of crops. Regardless of the hope and efforts of the farmers in Johns Valley, they too could not overcome the environment. Annual precipitation was often insufficient for dry farming in Johns Valley. Also, the erratic nature of the precipitation added to the downfall of farming activity in the valley, as adequate precipitation could not be relied upon from year to year or from month to month. Additionally, with Johns Valley being located 7,500 feet above mean sea level, the growing season was often too short to adequately allow crops to mature and produce a good yield. Other factors perhaps added to the discouragement of the people of Johns Valley, but the insufficient and erratic nature of the precipitation, coupled with the short growing season, were major factors in the abandonment of the area. The people of the valley voted to leave the area and sell their land and farms to the federal government.
40

Co-designing with “She Has a Name”: Active Learning for Johns and Best Practice Tools for John School Administrators

Fontenele de Matos Rodrigues, Natalia January 2022 (has links)
No description available.

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