• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 539
  • 266
  • 78
  • 72
  • 49
  • 46
  • 27
  • 14
  • 14
  • 9
  • 9
  • 9
  • 9
  • 9
  • 9
  • Tagged with
  • 1400
  • 336
  • 303
  • 200
  • 188
  • 175
  • 153
  • 150
  • 139
  • 126
  • 122
  • 116
  • 106
  • 92
  • 91
  • 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.
671

The effect of pressure afterload due to aortic coarctation on left ventricular function in children

Jashari, Haki January 2016 (has links)
Background: Coarctation of the aorta (CoA) is a congenital heart disease which represents a narrowing of the proximal descending aorta, hence increasing pressure afterload to the left ventricle (LV). Conventional treatment of native CoA is surgical repair, however potential recurrence or other related complications e.g. aortic rupture, heart failure and cerebrovascular events are common. Thus, lifelong follow-up of these patients is required. Echocardiography is the most patient’s friendly method to evaluate CoA and in particular its effect on LV function. Moreover, the novel speckle tracking echocardiography (STE) is an important method to assess subclinical LV dysfunction, a technique that promises better evaluation of LV function in these patients. The aims of this thesis were to review the literature on LV function in children with CoA using myocardial deformation imaging technologies, hence, to better understand the current knowledge and vagueness of the scientific evidence. We also aimed to study the effect of early CoA repair on the structure and function of LV and ascending aorta. In addition, we wished to establish in a meta-analysis format normal values of speckle tracking derived strain and strain rate values. Methods: Study 1. We have systematically searched the PubMed, and studies that fulfilled the inclusion criteria were critically analyzed and presented on a narrative form. Study 2 and 3. In addition to conventional echocardiographic measures of LV and ascending aorta, we measured longitudinal strain and strain rate of the LV using a vendor independent software, TomTec. We have also measured the aorto-septal angle (AoSA). Data was compared with normal healthy controls. Study 4. Electronic databases were systematically searched and suitable studies were meta analyzed using Comprehensive meta-analysis version 3 software. Results: Study 1. In 7/4945 included articles, 123 and 76 patients with congenital aortic stenosis (CAS) and CoA were reported, respectively. Normal conventional LV function, with subclinical myocardial dysfunction were reported in all studies before intervention. After intervention, a consistent improvement of myocardial deformation parameters was documented, even though not reaching normal values. Study 2. In 21 patients with CoA, LV function significantly improved after intervention (p <0.001), however normal values were not reached even at medium-term follow-up (p = 0.002). Medium-term longitudinal strain correlated with pre intervention LV ejection faction (EF) (r = 0.58, p = 0.006). Medium-term subnormal values were more frequently associated with Bicuspid aortic valve (BAV) (33.3% vs. 66.6%; p <0.05). Study 3. AoSA was abnormally wide before intervention, in particular at peak ejection in the descending aorta (p <0.0001), and correlated with CoA pressure gradient. After intervention, AoSA normalized and significantly correlated with the increase of LV cavity function and overall LV deformation parameters. Study 4. In a meta-analysis of 28/282 studies including 1192 subjects, strain and strain rate values were established. Longitudinal strain normal mean values varied from -12.9 to -26.5 (mean, -20.5; 95 % CI, -20.0 to -21.0). Normal mean values of circumferential strain varied from -10.5 to -27.0 (mean, -22.06; 95 % CI, -21.5 to -22.5). Radial strain normal mean values varied from 24.9 to 62.1 (mean, 45.4; 95 % CI, 43.0 to 47.8). Meta-regression showed LV end-diastolic diameter as a significant determinant of variation of longitudinal strain. Longitudinal systolic strain rate was significantly determined by age and radial strain was influenced by the type of vendor used. Conclusion: The systematic review showed subclinical LV dysfunction in children with CoA before and after correction. However, since most of the patients were operated at an older age and had preserved LV EF, the effect of early intervention on LV function was only speculated. Our children with CoA who were operated at an earlier age showed LV subclinical dysfunction even at medium- term after intervention while the AoSA returned to normal shortly after intervention. Lower longitudinal strain values were found in patients with LV dysfunction (LV EF <50%) before intervention and BAV. Finally, normal range values for strain and strain rate have been established and seem to be influenced by patients’ age, LV end-diastolic diameter and vendor used.
672

Das Weltbild der Autonomen im Spiegel der Zeitschrift <em>Interim</em> / The Autonomist Worldview As Reflected By the Magazine <em>Interim</em> : A content analysis of themes and discourses

Dietze, Sascha 06 April 2017 (has links) (PDF)
Die Autonomen sind die wichtigste Kraft im militanten Linksextremismus. Seit den 1980er Jahren machen sie mit Anschlägen oder „Massenmilitanz“ auf sich aufmerksam. Dietze beschäftigt sich in seiner Studie mit einem über lange Zeit zentralen Periodikum der Szene. Die Zeitschrift „Interim“ untersucht er hinsichtlich der in ihr geführten Themen und Diskurse. Ziel seiner Untersuchung ist es, Einblicke in das Denken der Autonomen zu geben. Hierfür arbeitet er zentrale, identitätsstiftende Positionen heraus. / The autonomists are the most important force in militant left-wing extremism. Since the 1980s they have been putting themselves in the public eye with attacks and "mass militance". In his study, Dietze focuses on a periodical that has been a lynchpin of the scene for many years. He examines the magazine "Interim" in terms of the themes and discourses it presents. His investigation aims to bring some insight into the mindset of autonomists. To this end, he maps out central identity-forming positions.
673

Museums in the Classroom: Preservation Virginia’s John Marshall House Trunk

De Leon, Denisse Marie 19 April 2010 (has links)
Since the No Child Left Behind Act (NCLB) was passed in 2001, museum educators have faced new challenges in designing programming that incorporates state standards of education while remaining faithful to the integrity of the museum’s collection and mission. Some museums have created programs that address these educational standards and can be used in school classrooms. This project is a case study of how one Virginia museum, Preservation Virginia, created a classroom program that addresses the state mandated Standards of Learning (SOLs). The report of this project includes discussion of the current debates that surround NCLB and its relationship to museum education. It also describes the five lesson plans included in the John Marshall House Trunk and explains why additions to those lesson plans have recently been created in order to incorporate inquiry-based teaching methods endorsed within museum education literature.
674

The Need for Caring Pedagogies: A personal look at education in depressed economies

Curran, Catherine 01 January 2007 (has links)
By grounding my work in this series of four essays in literary theory, but telling stories to which almost anyone can relate I hope to begin making the connection between sometimes heady academics and everyday working-class Americans. Only when learners understand their circumstances and the need for education, can they begin to take control of what they learn and how they employ that knowledge.
675

Tracking delivery of a drug surrogate in the porcine heart using photoacoustic imaging and spectroscopy

Furdella, Kenneth J., Witte, Russell S., Vande Geest, Jonathan P. 13 February 2017 (has links)
Although the drug-eluting stent (DES) has dramatically reduced the rate of coronary restenosis, it still occurs in up to 20% of patients with a DES. Monitoring drug delivery could be one way to decrease restenosis rates. We demonstrate real-time photoacoustic imaging and spectroscopy (PAIS) using a wavelength-tunable visible laser and clinical ultrasound scanner to track cardiac drug delivery. The photoacoustic signal was initially calibrated using porcine myocardial samples soaked with a known concentration of a drug surrogate (Dil). Next, an in situ coronary artery was perfused with DiI for 20 min and imaged to monitor dye transport in the tissue. Finally, a partially DiI-coated stent was inserted into the porcine brachiocephalic trunk for imaging. The photoacoustic signal was proportional to the DiI concentration between 2.4 and 120 mu g/ml, and the dye was detected over 1.5 mm from the targeted coronary vessel. Photoacoustic imaging was also able to differentiate the DiI-coated portion of the stent from the uncoated region. These results suggest that PAIS can track drug delivery to cardiac tissue and detect drugs loaded onto a stent with sub-mm precision. Future work using PAIS may help improve DES design and reduce the probability of restenosis. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)
676

How States are Meeting the Highly Qualified Teacher Component of NCLB

Pinney, Jean 20 May 2005 (has links)
As part of the reauthorization of the Elementary and Secondary Education Act the federal government has added the requirement that all schools receiving Title I funds must have "highly qualified teachers" in every classroom. The term "highly qualified teacher" comes from the No Child Left Behind Act of 2001. What exactly is a "highly qualified" teacher? This part of the law is widely debated throughout the fifty states, but most agree that a teacher's subject-matter knowledge and experience result in increased student achievement.(Ansell& McCase, 2003) Some states have made progress in meeting the "highly qualified" requirement of NCLB. However, most states have merely established the criteria for determining if a teacher is highly qualified (Keller, 2003). The Education Trust has called for clarification from the Department of Education on the guidelines for the teacher quality provision of the law. Ten states have put into law all the requirements of the federal law, 22 have done some work toward that goal, and 18 states still have a long way to go (Keller). With so many states still grappling with compliance to the law, this study may well give policy makers in those states options that are being used in other states to consider. In addition, the study focuses on middle school and the possible impact these requirements will have on staffing of middle schools. Policy makers would do well to look at this aspect closely since middle school is often where education "loses" many students to dropping out. Also, the middle school is where the greatest number of non-certified teachers are working and where the greatest percentage (44%) of teachers are teaching without even a minor in the subject they teach (Ingersoll, 2002).
677

The Brutal Reality of Bringing Kids up to Level: Are Critical Thinking and Creativity Lost in the World of Standardized Testing?

Carroll, Jamie M. 17 May 2013 (has links)
Since the passage of No Child Left Behind, the output of education has been measured through student achievement on standardized tests. School ratings, student graduation, teacher jobs and school charters are all tied to these tests. This study analyzes the extent to which math and science public high school teachers in New Orleans focus on critical thinking and creativity, skills needed to be successful in the future. Through a framework of Richard Paul’s model of critical thinking and Theresa Amabile’s social psychology of creativity, this study evaluates support for critical thinking and creativity through classroom observations, analysis of instructional materials and teacher interviews. Findings indicate that teachers at academically selective schools are more likely to support critical thinking and creativity in their classrooms than teachers at open enrollment schools. Classroom tests of participating teachers mainly focus on assessing basic knowledge and skills, not critical thinking and creativity.
678

Coarctation of the aorta : register and imaging studies

Rinnström, Daniel January 2016 (has links)
Background Coarctation of the aorta (CoA) constitutes 5-8 % of all congenital heart disease (CHD) and is associated with long-term complications such as hypertension (HTN) and left ventricular hypertrophy (LVH). Factors associated with HTN, LVH, and diffuse myocardial fibrosis, are not yet fully explored in this population. Methods Papers I-III: The Swedish national register of congenital heart disease (SWEDCON) was used to identify adult patients with repaired CoA. Paper IV: Data on 2,424 adult patients with CHD was extracted from SWEDCON and compared to controls (n = 4,605) regarding height, weight and body mass index (BMI). Paper V: Adults with CoA (n = 21, age 28.5 (19.1-65.1) years, 33.3 % female) referred for CMR were investigated with T1 mapping to determine left ventricular extracellular volume fraction (ECV). Results Papers I-II: Out of 653 patients, 344 (52.7 %) had HTN. In a multivariable model, age (years) (OR 1.07, CI 1.05-1.10), sex (male) (OR 3.35, CI 1.98-5.68) and BMI (kg/m2) (OR 1.09, CI 1.03-1.16) were associated with having HTN, and so was systolic arm-leg blood pressure (BP) gradient where an association was found at the ranges (10, 20] mmHg (OR 3.58, CI 1.70-7.55) and &gt; 20 mmHg (OR 11.38, CI 4.03-32.11), in comparison to the range [0, 10] mmHg. When investigating 243 patients with diagnosed HTN, 127 (52.3 %) had elevated BP (≥ 140/90 mmHg). Age (years) (OR 1.03, CI 1.01-1.06) was associated with elevated BP, and so was systolic arm-leg BP gradient in the ranges (10, 20] mmHg (OR 4.92, CI 1.76-13.79), and &gt; 20 mmHg (OR 9.93, CI 2.99-33.02), in comparison to the reference interval [0, 10] mmHg. Patients with elevated BP had more classes of anti-hypertensive medication classes prescribed (1.9 vs 1.5, p = 0.003). Paper III: Out of 506 patients, 114 (22.5 %) were found to have LVH. Systolic BP (mmHg) (OR 1.02, CI 1.01-1.04), aortic valve disease, (OR 2.17, CI 1.33–3.53), age (years) (OR 1.03, CI 1.01–1.05), and HTN (OR 3.02, CI 1.81-5.02), were associated with LVH, while sex (female) (OR 0.41, CI 0.24-0.72) was negatively associated with LVH. Paper IV: There was no difference in height, weight, or BMI between patients with CoA (n = 414) and the reference population. Paper V: In the population of 21 patients, an increased left ventricular myocardial ECV was found in 6 cases (28.6 %). Of the patients with increased ECV, 5/6 (83.3 %) were female (p = 0.002). Patients with increased ECV did not otherwise differ from the rest of the study population. iv Conclusions In adults with repaired CoA, HTN and LVH were common, and many patients with HTN had elevated BP despite treatment. The potentially modifiable factors BMI and systolic arm-leg BP gradient were associated with HTN, and the gradient was also associated with elevated BP among patients with diagnosed HTN. The gradient’s significance remained even within what the current guidelines consider acceptable ranges. Potentially modifiable factors associated with LVH were systolic BP and aortic valve disease. We found no general difference in height, weight, or BMI between patients with CoA and the reference population. While LVH was more common among men, increased myocardial ECV was more common among women.
679

Biomarqueurs de la fonction ventriculaire après un infarctus du myocarde : différences hommes-femmes / Biomarkers of left ventricular function after acute myocardial infarction : sex-biased differences

Lalem, Torkia 16 November 2018 (has links)
Les maladies cardiovasculaires sont la première cause de mortalité dans le monde. Les coronaropathies ischémiques dont l’infarctus du myocarde (IDM) sont responsables de la moitié de ces décès. Après un IDM, le cœur met en place un processus de cicatrisation afin de pallier la mort des cardiomyocytes et la perte de contractilité. S’il est dérégulé, ce processus peut conduire à un remodelage ventriculaire gauche (RVG) délétère qui altère la fonction ventriculaire (FV) et prédispose à l’insuffisance cardiaque. La découverte de nouveaux biomarqueurs capables de prédire le risque du RVG pourrait permettre d’améliorer la prise en charge des patients à risque et ainsi de réduire l’incidence de l’insuffisance cardiaque. De nombreuses différences ont été mises en évidence entre les hommes et les femmes avec IDM, et ce au niveau de la pathophysiologie, des symptômes, des biomarqueurs et même du processus du RVG. Ces différences impliquent le besoin de découvrir des biomarqueurs spécifiques à chaque sexe ou d’utiliser les biomarqueurs actuels différemment chez les femmes et les hommes. L’objectif de ce travail de thèse a été de mettre en évidence de nouveaux biomarqueurs de la FV après un IDM. Nous nous sommes particulièrement intéressés aux différences homme-femme dans les capacités prédictives de ces biomarqueurs. La première étude a eu pour objectif de valider l’association de cinq gènes avec la FV après un IDM établie lors d’études préliminaires. Une combinaison de trois gènes (LTBP4, TGFBR1 et TNXB) a été identifiée comme étant capable d’améliorer la prédiction de la dysfonction ventriculaire par les marqueurs actuels. Dans un second temps, nous avons montré dans une cohorte nationale d’IDM que le peptide natriurétique NT-proBNP n’était pas capable de prédire la FV chez les femmes alors que la troponine cardiaque était associée avec la dysfonction ventriculaire dans ce groupe. Dans une troisième étude, nous avons mis en évidence l’association entre le gène CDKN1C et la dysfonction ventriculaire spécifiquement chez les femmes. En conclusion, nos études contribuent à la découverte de nouveaux biomarqueurs du RVG post-IDM et attirent l’attention sur les différences hommes-femmes pour l’utilisation de ces biomarqueurs vers une médecine personnalisée / Cardiovascular disease is the first cause of mortality worldwide. Ischemic heart diseases among which myocardial infarction (MI), are responsible for half of these deaths. In order to cope with the loss of cardiomyocytes after MI and to attenuate the alteration of contractility, a repair process is implemented in the heart. If this repair process is dysregulated, it could lead to a maladaptive left ventricular remodeling (LVR) altering LV function and leading to heart failure. The discovery of novel biomarkers able to predict accurately the risk of LVR could lead to a better management of the patients at risk and reduce the incidence of heart failure. Many differences have been highlighted between men and women with MI, regarding the pathophysiology, the symptoms, levels of cardiac biomarkers and the process of LVR. These differences imply the discovery of novel sex-specific biomarkers for LVR prediction or the use of the known biomarkers in a sex-specific manner. The aim of this work was to discover novel biomarkers of left ventricular function (LVF) after an AMI, focusing on sex-differences. First, we aimed to validate the association between five genes previously found to be associated with LVF in small-scale studies. A panel of three genes (LTBP4, TGFBR1 and TNXB) was able to improve the ability of a clinical model to predict LVF. Second, we observed that the cardiac biomarker NT-proBNP was not predictor of LVF in women, whereas cardiac troponin was associated with LVF in this sex-group. A third study showed the association of the gene CDKN1C with LVF post-MI in a female-specific manner. In conclusion, our studies contribute to the discovery of novel biomarkers of LVF and draw the attention to sex differences in the clinical use of biomarkers towards the implementation of personalized medicine
680

Top-degree solvability for hypocomplex structures and the cohomology of left-invariant involutive structures on compact Lie groups / Resolubilidade em grau máximo para estruturas hipocomplexas e a cohomologia de estruturas involutivas invariantes à esquerda em grupos de Lie compactos

Jahnke, Max Reinhold 21 December 2018 (has links)
We use the theory of dual of Fréchet-Schwartz (DFS) spaces to establish a sufficient condition for top-degree solvability for the differential complex associated to a hypocomplex locally integrable structure. As an application, we show that the top-degree cohomology of left-invariant hypocomplex structures on a compact Lie group can be computed only by using left-invariant forms, thus reducing the computation to a purely algebraic one. In the case of left-invariant elliptic involutive structures on compact Lie groups, under certain reasonable conditions, we prove that the cohomology associated to the involutive structure can be computed only by using left-invariant forms. / Usamos a teoria da espaços duais de Fréchet-Schwartz (DFS) para estabelecer uma condição suficiente para resolubilidade em grau máximo para o complexo associado a estrutuas localmente integráveis hipocomplexas. Como aplicação, provamos que a cohomologia de estruturas hipocomplexas invariantes à esquerda podem ser calculadas usando apenas formas invariantes à esquerda, assim reduzindo o cálculo a um método puramente algébrico. No caso de estruturas invariantes à esquerda, sob certas condições razoáveis, provamos que a cohomologia associada à estrutura pode ser calculada usando apenas formas invariantes à esquerda.

Page generated in 0.0432 seconds