Intravascular ultrasound and magnetic resonance imaging of the pulmonary arteries in pulmonary hypertension

Two relatively new techniques by which the pulmonary arteries can be imaged in life are intravascular ultrasound and magnetic resonance imaging. The main aim of this thesis is to describe the changes which are detectable on intravascular ultrasound and magnetic resonance imaging in patients with pulmonary hypertension and to determine whether these imaging modalities could be of use for the clinical assessment of the condition.Intravascular ultrasound was performed in 10 young adults with Eisenmenger's Syndrome and 4 infants with pulmonary hypertension secondary to a left to right shunt. Vasodilator studies were performed in 5 of the patients with Eisenmenger's. The vessel wall appeared as a single echogenic layer in all patients, making it difficult to define or measure medial thickness with certainty. Morphological changes of intimal hypertrophy and atherosclerosis were evident in patients with Eisenmenger's whereas in the infants the intima appeared thin and smooth, typical of normal artery. The technique gave excellent definition of the vessel lumen allowing continuous measurement of changes in luminal dimensions in response to vasodilators.MRI of the pulmonary arteries was performed in 11 patients with Eisenmenger's and 6 normal controls. In patients with pulmonary hypertension the pulmonary arteries were found to be dilated with reduced distensibility 4 when compared with normals. Calculations of Qp:Qs by MRI in patients with systemic to pulmonary shunts and pulmonary hypertension did not correlate well with values from cardiac catheterisation in all patients.As intravascular and magnetic resonance imaging are confined to the elastic pulmonary arteries, quantitative morphological studies were peformed on 24 post mortem specimens of lungs from patients who had died with pulmonary hypertension to determine whether there was any correlation between changes in the elastic pulmonary arteries and severity of pulmonary vascular disease. When compared with normals there was medial thickening in those with pulmonary hypertension but this was of an insufficient degree to be detectable by current ultrasound catheters. There was no correlation between degree of medial thickening in the elastic pulmonary arteries and severity of pulmonary vascular disease but intimal thickening and atherosclerosis were evident in those with more advanced disease.In conclusion, magnetic resonance imaging was found to have limited role in the assesssment of pulmonary hypertension but with new technical developments could become a non-invasive method of studying pulmonary hypertension in the future. The morphological changes detectable by intravascular ultrasound tend to be in severe disease only but the technique provides a unique method of studying pulmonary vascular reactivity in life

Australian College of Nursing Rural Nursing and Midwifery Faculty: advocating for greater equity in rural health

[Extract] Working in rural Australia is a privilege and challenge that all rural nurses and midwives understand. Knowing the community, being known by the community, doing without, yet understanding much, can be achieved through innovative thinking and practice

A Multiple Indicators, Multiple Causes Analysis of Farmers\u27 Information Use

A multiple indicators, multiple causes, or MIMIC, modeling framework can be used for analyzing a variety of farmer decision-making situations where multiple outcomes are possible. Example applications include analyses of farmer use of multiple information sources, management practices, or technologies. We applied the framework to analyze use of multiple information sources by beef cattle farmers. We provide measures of how farmer demographics, farm characteristics, and risk attitudes influenced farmer use of information from Extension, producer groups, popular press, the U.S. Department of Agriculture, the Internet, and other farmers. Education and greater willingness to take risk positively influenced information use among the farmers we studied. Our process has implications for broader use within Extension

Population dynamics of coral-reef fishes : spatial variation in emigration, mortality, and predation

Understanding the dynamics of open marine populations is difficult. Ecological processes may vary with the spatial structure of the habitat, and this variation may subsequently affect demographic rates. In a series of observational and experimental studies in the Bahamas, I examined the roles of emigration, mortality, and predation in the local population dynamics of juvenile coral-reef fishes. First, I documented mortality and emigration rates in populations of bluehead and yellowhead wrasse. Assuming that all losses were due solely to mortality would have significantly underestimated survivorship for both species on patch reefs, and for yellowheads on continuous reefs. Mortality differed between species, but emigration did not differ between species or reef types. Mortality of blueheads was density-dependent with respect to both conspecific density and total wrasse density on continuous reefs. In contrast, mortality of yellowheads varied inversely with the density of blueheads on patch reefs. Emigration rates varied inversely with distance to the nearest reef inhabited by conspecifics. In subsequent experiments, I manipulated densities of yellowhead wrasse and beaugregory damselfish, and determined that the relationship between density and mortality varied with reef spatial structure. On natural reefs, mortality rates of the wrasse were highly variable among reefs. On artificial reefs, mortality rates of both species were density-dependent on spatially isolated reefs, yet high and density-independent on aggregated reefs. Heterogeneity in the spatial structure of natural reefs likely caused variation in predation risk that resulted in high variability in mortality rates compared to artificial reefs. A final experiment demonstrated that a single resident predator caused substantial mortality of the damselfish, regardless of reef spacing. Patterns suggested that resident predators caused density-dependent mortality in their prey through a type 3 functional response on all reefs, but on aggregated reefs this density dependence was overwhelmed by high, density-independent mortality caused by transient predators. These results (1) suggest post-settlement movement should be better documented in reef-fish experiments, (2) demonstrate that the role of early post-settlement processes, such as predation, can be modified by the spatial structure of the habitat, and (3) have ramifications for the implementation of marine reserves

Learning to Look, Looking to Learn

In order to plan and implement lessons that will be effective for a wide variety of learners, teachers must assess what students know and how they know it. They must also know students’ academic strengths, challenges, and preferences. Careful observation of what students do and say as they work provides a rich source of data about both their knowledge and ways of learning. We highlight three strategies we use to help teachers refine their understanding of individual students: (a) building teachers’ skills in observing without making judgements; (b) teaching teachers to use a shared, neurodevelopmental framework through which to view student learning and behavior; and (c) facilitating collaboration among general education and special education teachers in using these tools to assess student learning and plan lessons. The combination of careful observations, a neurodevelopmental lens through which to see and interpret the observations, and the different perspectives of general and special education teachers, builds a foundation for planning appropriately leveled and rigorous lessons that leverage students’ strengths while supporting them in their weaker areas.https://educate.bankstreet.edu/faculty-staff/1057/thumbnail.jp

Perspectives on Initiating Community-Based Participatory Research Partnerships

Community-based participatory research (CBPR) involves partnerships between academics and communities to address community priorities through collaborative research. Undergraduate student engagement in CBPR as part of an academic course is uncommon and there is limited evidence on the lessons learned about partnership initiation from course-based partnerships. This paper shares lessons from Medford and Tufts Community Health (MATCH), a course-based CBPR initiative. At the end of this course, three students, the instructor, and two community partners identified a list of four key lessons learned about partnership initiation. First, undergraduates should understand and explicitly attend to the privileges they bring to CBPR as students. Second, internal “champions,” who serve in a dual role in the community and university can provide students with important historical context to support partnership initiation. Third, students should assess and communicate what they can offer to community partners. Fourth, instructors should facilitate relationship building within student research teams. These lessons are critical for undergraduate instructors teaching CBPR courses and looking to initiate community partnerships with students