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A Structurally Based Investigation of Abdominal Aortic Aneurysms in Mouse ModelsCollins, Melissa 2011 December 1900 (has links)
Understanding the mechanical properties of Abdominal Aortic Aneurysms is paramount to improving treatment of this deadly condition. Here, we present work that makes strides in understanding not only the mechanical behavior and constitutive parameters of the two vessels that experience AAAs in different models, but also the
effects of three major components of AAA formation. Biaxial mechanical tests were performed using a modified computer- controlled device.
We examined the solid mechanics of the infrarenal and suprarenal aorta to examine why non-targeted models of AAAs (like Ang-II infusion) form exclusively in
the suprarenal aorta whereas in humans the lesions preferentially form in the infrarenal aorta. The major difference between the two vessels is the elastin content and lamellar thickness in the suprarenal aorta.
We analyzed the mechanical and constitutive effects of an acute loss of functional elastin via intraluminal exposure to elastase. We found that after elastase exposure, vessels were less distensible and experienced non-uniform, but modest dilatation. The constitutive parameters reflect elastin loss and increased collagen loading.
We detailed the loss of smooth muscle cell contractility as found in human lesions that form in the thoracic aorta. We examined wild-type (WT), heterozygous
(HET), and null (KO) a-smooth muscle actin (a-SMA) mice. The data and associated constitutive parameters were nearly identical amongst the three groups.
We studied the biaxial mechanical tests on Angiotensin-II-infused ApoE-/- mice. This model is common model of AAA; however, instead of dilation and a thinning of the
wall as in AAAs, Ang-II results in a dissecting aneurysm with adventitial growth. The pressure-diameter curves show a lack of sigmoidal shape attributed to elastin, there is some distensibility. The pressure-force behavior of these vessels is similar to a native vessel, unlike the pressure-force behavior of the elastase vessels.
We have added a piece to the puzzle in understanding why AAAs occur preferentially in the suprarenal in mice as opposed to the infrarenal in humans. Our
work with the a-SMA mice, introduces the idea that missense mutations in the ACTA2 gene, rather than the knocking out of the gene, leads to vascular diseases. We have increased the knowledge of the Ang-II infusion model by presenting biaxial mechanical data of the resulting dilatations. We have also further explored this widely used AAA
model via histology to determine that in it is not a model for aneurysm development, but
is a dissecting adventitial disease.
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Tala är silver, tiga är guld : En studie om barnperspektivet inom socialtjänsten i de kommuner där BBIC användsRippling, Jessica January 2014 (has links)
Syftet med studien är att undersöka hur barnperspektivet används i det dagliga arbetet. Avsikten är också att undersöka hur barnens inflytande ser ut över de beslut som fattas kring deras livssituation. Studien genomfördes genom intervjuer med socialsekreterare på socialtjänsten. Teorin som användes är systemteori, även barnperspektivet och ett teoretiskt perspektiv på dominansförhållanden i samtal med barn tillämpas. Med hjälp av ovan nämnda teorier och teoretiska perspektiv analyseras och förklaras hur socialsekreterarna använder barnperspektivet. Resultatet visar att socialsekreterarna använder barnperspektivet i begränsad omfattning men att det finns en ambition att alltid utgå från barnets bästa. / The aim of this study is to examine how social workers use the child’s perspective in their daily work. The purpose is also to examine how the children are able to influence the decisions made about their lives. The study is conducted using a qualitative approach. The theory used is system theory and two theoretical perspectives: children’s perspective and the fact that there is a dominance relationship in conversations with children. The conclusion that can be drawn from this study is that social workers use children's perspective on a limited basis but there is an ambition to always proceed in a manner on the child’s best.
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Clinical signs and electrophysiological studies of naturally occurring and experimentally induced bovine spongiform encephalopathy and their relationship to pathological diagnosisKonold, Timm January 2011 (has links)
No description available.
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Direct observation as a measuring instrument in caregiver-and-child attachment : a social work investigation / by Lindie NellNell, Lindie January 2008 (has links)
In this dissertation 9 social workers working in Pretoria, Gauteng Province were interviewed. The focus of these interviews was regarding the use of direct observation as a measuring instrument for the purpose of assessing attachment of the caregiver-and-child's relationship. This information jointly with a two-fold literature study served as the foundation for a proposed preliminary practise framework.
The completed research is described in the article format in two articles. Article 1 contains the literature study on attachment theory and its application to direct observation of attachment of the caregiver and child's relationship. Article 2 contains the literature study on direct observation measuring instruments for the purpose of assessing attachment of the caregiver-and-child's relationship. Direct observation measuring instruments used by experienced social workers were also examined by means of an empirical investigation.
The practise framework acts as preliminary guidelines giving direction into the usage of direct observation as a structured measuring instrument in assessing the caregiver-and-child's attachment relationship. / Thesis (M.A. (MW))--North-West University, Potchefstroom Campus, 2009.
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Direct observation as a measuring instrument in caregiver-and-child attachment : a social work investigation / by Lindie NellNell, Lindie January 2008 (has links)
In this dissertation 9 social workers working in Pretoria, Gauteng Province were interviewed. The focus of these interviews was regarding the use of direct observation as a measuring instrument for the purpose of assessing attachment of the caregiver-and-child's relationship. This information jointly with a two-fold literature study served as the foundation for a proposed preliminary practise framework.
The completed research is described in the article format in two articles. Article 1 contains the literature study on attachment theory and its application to direct observation of attachment of the caregiver and child's relationship. Article 2 contains the literature study on direct observation measuring instruments for the purpose of assessing attachment of the caregiver-and-child's relationship. Direct observation measuring instruments used by experienced social workers were also examined by means of an empirical investigation.
The practise framework acts as preliminary guidelines giving direction into the usage of direct observation as a structured measuring instrument in assessing the caregiver-and-child's attachment relationship. / Thesis (M.A. (MW))--North-West University, Potchefstroom Campus, 2009.
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Biased perceptions of alibis and suspects: an elaboration likelihood model perspective on alibi believabilityAllison, Meredith 18 December 2009 (has links)
When do stereotypes and biases affect judgments of alibis and crime suspects? Two studies addressed this question. Undergraduates (N- 192 in Study 1, N= 339 in Study 2) listened to an audio-taped police interview with a suspect concerning his/her alibi. Participants then rated the believability of the alibi and the likelihood that the suspect was guilty. The impact of: (1) the strength of the evidence that supported the alibi; (2) characteristics of the suspect (e.g., gender, attractiveness, and prior convictions); (3) judge's instructions on prior conviction evidence; and (4) perceivers' motivation to process the alibi (using scores on the Need for Cognition Scale) on alibi believability and likelihood of suspect guilt ratings was studied. Other dependent measures were assessments of the suspect's character and participant-jurors' understanding of judicial instructions. It was found that the suspect's gender and level of physical attractiveness did not affect alibi believability and guilt ratings, but were important when it came to assessing the suspect's character. Participants took the defendant's prior record into consideration when assessing guilt: Defendants previously convicted of the same crime as the current charge were seen as more likely to be guilty than defendants previously convicted of a different crime. Judge's instructions did not affect guilt ratings, which suggests that participants did not use the prior conviction evidence as they had been instructed. In contrast to predictions, need for cognition played less of a role in terms of alibi believability ratings and guilt judgments. However, NFC did affect participants' understanding of judicial instructions and their recall of those instructions. The two studies suggest that alibi strength consistently influences believability and guilt ratings. Strong alibis were seen as more believable and led to lower guilt ratings than weak alibis. Limitations of this dissertation, legal implications, and future directions are discussed.
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Laboratory Investigation Of Natural Air Convection In A Porous Medium In A Cylindrical TankChen, Jianfeng 11 1900 (has links)
Natural convection with high cooling effects is of increasing interest in cold region geotechnical engineering. To study natural air convection in a highly-permeable porous medium, convective and conductive heat transfer experiments were carried out using an insulated cylindrical tank filled with styrofoam chips. Convection and conduction were caused by controlling the temperatures at the top and bottom of the tank, and a series of cross-sectional conductive and convective isotherms were generated from collected temperature data. Additional convective patterns were obtained from tests by centrally localized heating below or cooling above. Flow velocities were measured at the center of the tank. Results showed that convective heat transfer rate was higher than thermal conduction. Convective isothermal patterns varied with various boundary conditions and could be influenced by small temperature perturbation. Given appropriate environmental conditions, efficient convective cooling effects can be used to enhance ground freezing or to protect permafrost from degradation. / Geotechnical Engineering
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Police corruption and strategies for its prevention in the emirate of Abu DhabiAl-Muhairi, Humaid Mohamed Saed January 2008 (has links)
Police Corruption is a complex widespread phenomenon in many developed and developing countries though the intensity varies from country to country. The current study is one of several studies supported by the UAE government will explore the different ways of police corruption and examine the potential ways of external mechanisms to control and minimize police corruption in the state of Abu Dhabi, which is one of the emirates of the United Arab Emirates. The methodology used for this research was by means of collecting data through a survey method distributed in the form of a questionnaire among a large population of police personnel and the public. The collected data was then analysed quantitatively and qualitatively. This research proved that unacceptable police behaviour existed (64.4%), with traffic, investigation and the immigration departments being the highest. Favouritism and nepotism have been identified as the most types of unacceptable behaviour which exists within the Abu Dhabi police force. Police officers (70%) agree to use violence and excessive force against suspects and (54%) believed that the public were worried about repercussions if any complaint was made about corrupt officers. It was established that unacceptable police behaviour exists in Abu Dhabi police force and traffic, investigation and the immigration departments have been identified with the highest levels of unacceptable police behaviour. Police corruption is more often a local police culture involving favouritism and nepotism that protects and even encourages unacceptable police behaviour. Finally, the research suggests the important role of media, public awareness, and training as remedies that should be adopted for instituting long term reforms. A combination of approaches, as well as federal supervision, is needed.
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Dendroclimatological investigation of river red gum (Eucalyptus camaldulensis Dehnhardt)Argent, Robert Murray Unknown Date (has links) (PDF)
This thesis examines the growth ring structure of Eucalyptus camaldulensis Dehnhardt and investigates links between ring features and the climatic conditions under which growth took place. Samples of E. camaldulensis from the Barmah Forest (near the River Murray in northern Victoria) were used in the study. E. camaldulensis growth is linked to periodic flooding, and the Barmah Forest contains sites that are frequently flooded. Wood samples were obtained from sites subject to different average flooding frequencies. Trees used in the study grew out of natural regeneration in the 1920’s and 1930’s and from regeneration trials in the early 1960’s. Initial investigation of E. camaldulensis samples revealed ring-like features that were able to be traced on samples by eye. Microscopic investigation showed that there existed considerable variations in the properties of individual rings at different positions on the samples, and that the boundaries between rings were often indistinct.
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Radar and optical studies of the atmosphere.Reid, Iain M. January 2008 (has links)
The research described in this thesis can be categorized into three main areas. The first area concerns the interpretation of observations of various atmospheric processes and phenomena. The focus here has been on internal atmospheric gravity waves and their manifestation in radar winds and in airglow intensities, but also includes investigation of atmospheric tides and planetary scale waves, D-region electron densities and collision frequencies, the aspect sensitivity of backscattering and partially reflecting regions of the atmosphere, Polar Mesosphere Summer Echoes and Mesosphere Summer Echoes, meteor trails, mesospheric temperatures, long period variations in airglow intensities, and Kelvin Helmholtz Instabilities. The second major area has been in the development of new experimental techniques and the validation of existing techniques for investigating the atmosphere. New techniques have included the dual–beam radar technique for measuring momentum fluxes, and radar Time Domain Interferometry and Hybrid Doppler Interferometry for use with multi-receiver channel Doppler radars. The Doppler Beam Steering technique in the presence of non-uniform and periodically varying wind fields has been investigated analytically, and various spaced sensor techniques have been investigated using a numerical model of atmospheric radar backscattering and by direct comparison with other techniques. The Sodium Lidar technique has been investigated through numerical model calculations and a solid state system is currently being developed. Finally, a major activity has been the development of new radars and radar subsystems. This has included the development of a modular Medium Frequency Doppler radar and a Medium Frequency Spaced Antenna radar, a variety of Stratosphere Troposphere / Mesosphere Stratosphere Troposphere radars, an Ionospheric radar, a Boundary Layer Tropospheric radar and an All-Sky meteor radar. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1347218 / Thesis (D.Sc.) - University of Adelaide, School of Chemistry and Physics, 2008
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