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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

Perceptions of Failed Foster Care

Mitchell, Nathaniel 01 January 2019 (has links)
Abstract The purpose of this action research study was to investigate social workers' perceptions of the problems that prevent successful family reunifications after foster care. The study explored social workers' perceptions of barriers that prevent family reunifications in central Mississippi. Using Bronfenbrenner's ecological theory as the framework, the research question explored the problem from multiple levels of practice including family, individual, institutional, and community. The focus group approach aligned with the project goal by allowing participants opportunities to share experiences and perspectives regarding family reunifications. The study used a purposive sample of 10 participants who were practicing licensed social workers or certified mental health professionals in central Mississippi. Focus group responses were transcribed and coded by defining categories, assigning labels, and classifying relevant information using the comparative method. The key results of the study included that family reunification was impeded by the lack of training of child welfare social workers and limited resources to address psychosocial issues. The recommendations of the study included improving practice by engaging in mental health screening for foster children and families, promoting current knowledge and interventions by addressing psychosocial issues, and participating in program evaluation by targeting and strengthening policies. The impact of this study for positive social change includes understanding critical issues of family reunification after foster care stemming from lack of resources, unstable placements, and mental health issues.
32

Inflammation and Coagulation Activity in Unstable Coronary Artery Disease and the Influences of Thrombin Inhibition

Oldgren, Jonas January 2001 (has links)
<p>In patients with unstable coronary artery disease, this study evaluated the degree of inflammation and coagulation activity, relations to myocardial cell damage, prognosis, and influences of randomisation to 72 h infusion with three different doses of inogatran, a direct thrombin inhibitor (n=904), or unfractionated heparin (n=305). </p><p>Anticoagulant treatment effects were evaluated with aPT time. In inogatran treated patients with aPT times ≥ 44 s (median), the 7-days event rate - death, myocardial infarction or refractory angina – was 11.6 %, compared to 6.6 % with aPT times < 44 s (p=0.01). Higher aPT times was related to improved outcome during heparin treatment.</p><p>Markers of inflammation, i.e. fibrinogen and C-reactive protein (CRP), and coagulation, i.e. prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), soluble fibrin (SF) and D-dimer were analysed in serial samples (n=320). High fibrinogen, F1+2 and D-dimer levels persisted at 30 days. Patients with myocardial damage, detected by elevated troponin, had higher levels of all markers except TAT.</p><p>Ischemic events occurred at 30 days in 17 % of patients with high (pre-treatment top tertile) and 8.5 % of patients with lower fibrinogen levels (p=0.03), while high CRP levels only were related to increased mortality. At 30 days, patients with high compared to low pre-treatment levels of TAT or SF had 40 % lower event rate. Patients with early decreased compared to raised F1+2 or TAT levels during treatment had 50 % lower 30-days event rate (p<0.05). </p><p>Conclusions: The aPT time is an inappropriate indicator of antithrombotic efficacy. The raise in fibrinogen in the acute phase is sustained, and indicates risk of thrombosis and new ischemic events. The pronounced CRP elevation is transient, but associated with increased mortality. Higher coagulation activity may identify patients with a thrombotic condition as the major cause of instability, who are best responders to anticoagulant therapy. However, reactivation of coagulation activity with raised risk of ischemic events is a concern at cessation of treatment.</p>
33

Inflammation and Coagulation Activity in Unstable Coronary Artery Disease and the Influences of Thrombin Inhibition

Oldgren, Jonas January 2001 (has links)
In patients with unstable coronary artery disease, this study evaluated the degree of inflammation and coagulation activity, relations to myocardial cell damage, prognosis, and influences of randomisation to 72 h infusion with three different doses of inogatran, a direct thrombin inhibitor (n=904), or unfractionated heparin (n=305). Anticoagulant treatment effects were evaluated with aPT time. In inogatran treated patients with aPT times ≥ 44 s (median), the 7-days event rate - death, myocardial infarction or refractory angina – was 11.6 %, compared to 6.6 % with aPT times &lt; 44 s (p=0.01). Higher aPT times was related to improved outcome during heparin treatment. Markers of inflammation, i.e. fibrinogen and C-reactive protein (CRP), and coagulation, i.e. prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), soluble fibrin (SF) and D-dimer were analysed in serial samples (n=320). High fibrinogen, F1+2 and D-dimer levels persisted at 30 days. Patients with myocardial damage, detected by elevated troponin, had higher levels of all markers except TAT. Ischemic events occurred at 30 days in 17 % of patients with high (pre-treatment top tertile) and 8.5 % of patients with lower fibrinogen levels (p=0.03), while high CRP levels only were related to increased mortality. At 30 days, patients with high compared to low pre-treatment levels of TAT or SF had 40 % lower event rate. Patients with early decreased compared to raised F1+2 or TAT levels during treatment had 50 % lower 30-days event rate (p&lt;0.05). Conclusions: The aPT time is an inappropriate indicator of antithrombotic efficacy. The raise in fibrinogen in the acute phase is sustained, and indicates risk of thrombosis and new ischemic events. The pronounced CRP elevation is transient, but associated with increased mortality. Higher coagulation activity may identify patients with a thrombotic condition as the major cause of instability, who are best responders to anticoagulant therapy. However, reactivation of coagulation activity with raised risk of ischemic events is a concern at cessation of treatment.
34

White wine continuous protein stabilisation: industrial viablity

Salazar González, Fernando Noé 25 January 2008 (has links)
Las proteínas térmicamente inestables que están presentes en uvas, jugos de uva y vinos podrían llegar a ser insolubles y precipitar causando la formación de turbidez o precipitados indeseables en vinos blancos después del embotellado durante el almacenamiento.La turbidez proteica en vinos blancos es evitada tradicionalmente, mediante la adición de bentonita, aunque esta técnica presenta algunas desventajas tales como efectos negativos sobre las propiedades sensoriales del vino debido principalmente a la remoción de componentes aromáticos o gustativos y por la merma de vino, debido al gran aumento de volumen y poder de sedimentación de la bentonita. Además, el recurso humano, los tiempos de proceso y la descarga de residuos al ambiente sigue siendo una inmensa preocupación, debido a los significativos costos asociados a la salud y seguridad laboral, y así como también las responsabilidades y obligaciones legales de la industria en material de impacto ambiental. Es estimado que los costos del uso de la bentonita en la industria del vino a nivel mundial son del orden de los 300-500 millones de dólares por año. Por lo tanto es necesario el desarrollo de nuevas tecnologías alternativas a la bentonita que sean económicamente viables y que mantengan la calidad del vino, así como también la generación de un menor impacto ambiental. No obstante, nuevas técnicas exitosas a nivel industrial aun no han sido desarrolladas, por que afectan la calidad del vino o porque su aplicación no es viable económicamente bajo normales condiciones de operación de producción de vino. Por lo tanto, es muy atractivo investigar la viabilidad de nuevas prácticas que tengan un menor impacto sobre el ambiente y sean económicamente viables.Por esa razón la principal motivación de nuestra investigación ha sido estudiar la viabilidad industrial de una tecnología alternativa al uso de la bentonita, la cual permita remover proteínas inestables de los vinos blancos usando zirconia como material adsorbente. Además, nosotros nos hemos concentrado en el desarrollo de un proceso continuo que permita conseguir vinos estables proteicamente sin afectar sus propiedades fisicoquímicas y sensoriales, probando diferentes técnicas de regeneración del material adsorbente. Primeramente nosotros hemos estudiado la estructura, morfología y propiedades superficiales de la zirconia, así como también su capacidad de adsorción para remover proteínas inestables de vinos blancos, aplicando tratamientos regenerativos químicos y térmicos. Después hemos comparado las propiedades fisicoquímicas y sensoriales de un vino blanco estabilizado proteicamente mediante zirconia y bentonita.Además, nosotros hemos desarrollado un proceso híbrido integrando un proceso de adsorción en columna y un proceso de microfiltración tangencial de vino, para conocer los efectos de este nuevo proceso sobre el ensuciamiento de la membrana y la estabilidad proteica del vino.Por otro lado, nosotros también hemos aplicado un nuevo proceso de estabilización proteica de vino base para cava, comparando los resultados con el método tradicional usando bentonita como agente estabilizante y observando los efectos de ambos tratamientos sobre la calidad de la espuma y las fracciones proteicas del vino. Finalmente, hemos aplicado el nuevo proceso de estabilización proteica a escala industrial, empacando zirconia sobre una columna fija y realizando el proceso mediante sistema continuo y discontinuo.Los resultados demuestran que la zirconia puede ser regenerada química o térmicamente, que sus propiedades físicas, morfológicas y químicas no son alteradas y que incluso su capacidad de adsorción proteica podría ser aumentada probablemente producto de la adsorción de algunos componentes o centros activos derivados de las proteínas del vino. A través del proceso híbrido ha sido posible conseguir vinos estables proteicamente y aumentar la densidad de flujo del permeado durante la microfiltración del vino. De hecho, hemos observado que la reducción de proteínas mediante la adsorción en columna usando zirconia también ocurre durante la microfiltración tangencial, por lo tanto ambos procesos pueden actuar conjuntamente en la reducción y estabilización proteica.Por otro lado, comparando las propiedades fisicoquímicas y sensoriales de vinos blancos estabilizados proteicamente mediante zirconia y bentonita, podemos afirmar que los mejores resultados son conseguidos usando zirconia como agente estabilizante.La estabilización proteica de vinos blancos en continuo también puede ser útil para estabilizar vinos base para cava, ya que comparando la calidad de la espuma de un vino base para cava tratado con zirconia y bentonita, los resultados demuestran que la calidad de la espuma de aquellos vinos bases es mejor usando zirconia, ya que la adicción de bentonita produce considerables efectos negativos sobe la calidad de la espuma.Finalmente, los resultados obtenidos a escala industrial, muestran que es viable la estabilización proteica de vinos blancos usando zirconia como material adsorbente ya sea mediante un sistema continuo o discontinuo sin afectar la calidad del vino inicial. / Heat-unstable soluble proteins in grapes, grape juices and wines may become insoluble and precipitate causing the formation of undesirable hazes or deposits in white wines after bottling and during storage. Proteins are commonly prevented from forming hazes with bentonite, though this technique does have drawbacks: for example, the sensory properties of the wine are affected adversely because flavour compounds are removed and wine volume is lost as lees because of the swell and settling of the bentonite. In addition, the handling and disposal of spent bentonite continues to be a concern, because it involves high labour input and the associated costs, occupational health and safety issues, and the wine industry's environmental responsibilities and legislative requirements. It is estimated that the cost of bentonite fining to the wine industry worldwide is in the order of US$300-500 m per annum. Alternative fining technologies to bentonite, which are economically viable and maintain wine quality, are currently being sought. However, no successful techniques have been developed to date: all the attempts so far have either affected the quality of the wine or not been economically viable under standard winemaking conditions. Therefore, research on the implementation of new practices that have a less negative impact on the environment and are economically viable is particularly challenging.For this reason the aim of this thesis was to study the industrial viability of an alternative technology to bentonite fining which enables unstable proteins to be removed from white wines using zirconia as the adsorbent material. We also attempted to develop a continuous process, which stabilizes wine protein without having any negative effects on the physicochemical and sensory properties of the wine. Likewise we tried to make the process have a lower environmental impact by testing various regenerative treatments of the adsorbent material.First we studied the structure, morphology and surface properties of the zirconia and its capacity to remove unstable proteins from white wine versus thermal and chemical regeneration treatments. Subsequently we compared the physicochemical and sensory properties of a white wine fined by zirconia and bentonite. To further our understanding of the effect on membrane fouling and wine protein stability, we developed a hybrid process consisting of in-column adsorption with crossflow microfiltration. We also applied this new method to stabilize the base sparkling wine and compared the results with the conventional method of using bentonite as the fining agent to see the effects of the treatments on the foam quality and protein fractions. Finally, we applied the new method on an industrial scale by packing zirconia into a fixed bed column and by using the batch and continuous systems.The results show that the zirconia can be regenerated by thermal and chemical treatments, and that its physical, morphological and chemical properties are not altered. In fact its protein adsorption capacity can increase probably because some compounds or active centres derived from wine proteins are absorbed.The hybrid process was used to increase the permeate flux during crossflow microfiltration and stabilize wine proteins. We observed that proteins were reduced when the zirconia column adsorption was used during the crossflow microfiltration. Therefore both processes may act together.By comparing the physicochemical and sensory analyses of white wine proteins stabilized by zirconia and bentonite, we found that results were best when zirconia was used.The continuous protein stabilization of white wines by zirconia may also be useful for stabilizing proteins in base sparkling wines. Treating base sparkling wines with zirconia definitely gives better foam quality than with bentonite. Finally the results obtained in our industrial scale experiment showed that white wine continuous protein stabilization with zirconia as the adsorbent material is not only viable in both the continuous and batch systems, it also leaves the quality of the wine unchanged.
35

Urban Stream Channel Geomorphology: Investigating the Short-Term Channel Stability and Bed-Material Transportation within a Rehabilitated Urban Stream Reach in DeKalb County, Georgia

Shoredits, Andreas 20 December 2012 (has links)
Rivers and streams are sensitive to alterations in their watersheds and one of the greatest disturbances is from urban development. An urban stream channel in the Atlanta metropolitan area in the Georgia Piedmont was studied to establish the nature of adjustment the channel form was experiencing. This study compared a degraded channel with a channel influenced by stabilization efforts in the same stream reach, in order to investigate the behavior of channel adjustments towards a greater stability. Measurements of the short-term changes in channel cross-sectional area and bed-material volume, following a series of threshold flow events, were taken in the reach and the variation in bed sediment texture was also investigated. Results showed that channel banks were stable compared to more mobile beds and that urban effects continued to dictate sedimentation. Rehabilitation measures were aggrading channels in their reaches and were likely perpetuating the instability of upstream channels.
36

Effects Of Swiss Ball Training On Knee Joint Reposition Sense, Core Strength And Dynamic Balance In Sedentary Collegiate Students

Cug, Mutlu 01 February 2012 (has links) (PDF)
The purpose of this study was to investigate the effects of Swiss ball training on (1) knee joint reposition sense (knee proprioception), (2) core muscle strength and (3) dynamic balance in sedentary collegiate students. In this thesis, two different participant groups and two different training methods were used. In order to evaluate the effect of Swiss ball training on knee proprioception and core strength, 3 days per week training was conducted throughout 10 weeks (Study 1). In order to evaluate the effect of Swiss ball training on dynamic balance, 2 days per week training was conducted throughout 10 weeks (Study 2). 60 sedentary university students participated in Study 1. 47 sedentary university students participated in Study 2. The results of the study indicated that Swiss ball training has significant effect on knee proprioception and core muscle strength. For dynamic balance, at the end of the 10-week Swiss ball training, in both groups (Swiss ball and control), dynamic balance scores were improved significantly. Therefore, effect of the Swiss ball training on dynamic balance could not be determined. As a conclusion, an instability training program using Swiss balls with body weight as resistance can provide prolonged improvements in joint proprioception and core strength which would contribute to general health and performance.
37

Numerical analysis of random dynamical systems in the context of ship stability

Julitz, David 26 August 2004 (has links) (PDF)
We introduce numerical methods for the analysis of random dynamical systems. The subdivision and the continuation algorithm are powerful tools which will be demonstrated for a system from ship dynamics. With our software package we are able to show that the well known safe basin is a moving fractal set. We will also give a numerical approximation of the attracting invariant set (which contains a local attractor) and its evolution.
38

Stability Analysis of a MEMS Acceleration Sensor

Wolfram, Heiko, Dötzel, Wolfram 05 February 2007 (has links) (PDF)
The electrostatic actuation with its several advantages is the main principle for micro-electro-mechanical systems (MEMS). One major drawback is the nonlinear behavior, which results into instability, known as the electrostatic pull-in effect. This effect might also push a closed-loop configuration into instability and thus makes a linear time-invariant control inapplicable to the system. The paper investigates the stability of an acceleration sensor in closed-loop operation with this setting. A simplified controller adjustment gives a first insight into this topic. Practical implementations saturate on the quantizer's full-scale value, which is also considered in the stability analysis. Numerical phase-plane analysis verifies the stability and shows further surprising results.
39

A biophysical study of intranuclear herpes simplex virus type 1 DNA during lytic infection

Lacasse, Jonathan J Unknown Date
No description available.
40

Non steroidal anti-inflammatory drugs and cardiovascular risk: identifying evidence for channelling bias in a population based study

2015 July 1900 (has links)
ABSTRACT The non-steroidal anti-inflammatory drug (NSAID), diclofenac, has been associated with a high risk for cardiovascular events in observational studies. However, majority of studies identifying this association were conducted when diclofenac was the only NSAID that could be obtained as a combination product (i.e., formulated with misoprostol). As a result, channelling bias might have resulted if prescribers selected the combination of diclofenac/misoprostol (Diclo-Miso) in patients with poor health status frequently than other NSAID products. The main purpose of this study was to identify evidence for channelling bias in a cohort of patients with coronary heart disease (CHD) prescribed NSAIDs. Three independent, retrospective analyses were carried out using Saskatchewan’s health administrative databases. Patients were eligible if they were hospitalized with CHD event between January 1, 1994 and December 31, 2008. In the first analysis, a time series was conducted to examine trends in the use of NSAIDs following discharge from original hospitalization. In the second analysis, multivariate logistic regression models were constructed to identify characteristics of patients prescribed with Diclo-Miso in comparison to single-entity diclofenac. Finally, a nested case-control study was conducted to examine the risk for recurrent myocardial infarction (MI)/ Unstable Angina (UA) or death among patients prescribed with Diclo-Miso versus single-entity diclofenac. For each case, up to five controls were matched by age and sex. Between 1994 and 2008, NSAIDs were used by 20.1% (3,099/15,393) of patients in the year following discharge from their original MI/UA hospitalization. Use of these agents was relatively stable until 2004 when the COX-2 selective agent rofecoxib was withdrawn from the market. Following this date (i.e., September 30, 2004), the use of Diclo-Miso and single-entity diclofenac appeared to follow different trends. However, available patient and disease specific factors could not explain diverging utilization trends. Further, no differences were observed in the risk of experiencing recurrent MI/UA between patients receiving Diclo-Miso (OR 0.88, 95% CI 0.72-1.08, p=0.22) or single-entity diclofenac (OR 0.78, 95% CI 0.60-1.00, p=0.06) versus patients not exposed to NSAIDs. Based on the study’s result, channelling bias does not appear to be a major threat to the analysis of cardiovascular toxicity of diclofenac products.

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