The baroreceptor reflex emanating from the carotid sinus and common carotid artery of the sheep : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Physiology at Massey University

The aim of this project was to improve understanding of the role of the common carotid arterial baroreceptor mechanism in controlling peripheral blood pressure in the sheep. The responses to clamping of one or both common carotid arteries were examined under chloralose anaesthesia with the vagus nerves intact and after they had been sectioned. Unilateral clamping of a common carotid artery immediately reduced the mean blood pressure and pulse pressure in the ipsilateral carotid sinus and raised the peripheral mean blood pressure and pulse pressure. The failure of sinus pressures to show any recovery in the clamped vessel suggests that there was minimal flow through anastomoses into the occluded artery. Bilateral clamping of the common carotid arteries reduced the mean blood pressure within both carotid sinuses to a lower level than unilateral clamping, but raised the peripheral mean blood pressure and pulse pressures to a greater degree. This pressor response was interpreted as being due to the larger population of baroreceptors detecting the low carotid sinus pressures during bilateral occlusion. To test whether there was a tendency for common carotid arterial clamping at different levels to produce different reflex responses of peripheral blood pressure, the carotid arteries were occluded at the caudal, mid- and cranial cervical levels. There was a trend towards a greater rise in peripheral mean blood pressure during caudal clamping compared with cranial clamping. This too may be due to a larger population of baroreceptors detecting the low carotid sinus and common carotid arterial pressures and suggests baroreceptors are distributed in regions of the common carotid artery caudal to the sinus. In one third of the sheep, clamping the left common carotid artery caused a greater rise in peripheral mean blood pressure than clampinq of the right vessel. Possible reasons for this include the presence of a larger population of baroreceptors in the left artery than the right and differences in the sensitivity of receptors in the two vessels. The variability of responses to clamping and vagotomy was emphasised by the responses of two sheep in which section of the right vagus nerve totally abolished the reflex response to right common carotid arterial occlusion. Since in these animals neither the size of the baroreceptor population nor its sensitivity appeared to be responsible, a conclusion consistent with the evidence is that the baroreceptors in the vessel were innervated by the recurrent laryngeal or vagus nerves. Overall in the experiments, bilateral vagotomy enhanced the peripheral mean blood pressure and pulse pressure responses to clamping the common carotid arteries in keeping with a loss of the input from the aortic arch and cardio-pulmonary baroreceptors. Histological evidence of the distribution of sensory areas along the common carotid artery was obtained for three discrete areas (A, B and C). It is suggested that baroreceptors located in the common carotid artery may be less sensitive than those in the carotid sinus region because of the low elastin content and lack of tunica medial thinning at the sites of carotid arterial baroreceptor innervation

Trois Pieces en Forme de Poire (Three Pieces in the Shape of a Pear)

We all play roles in life. This paper is a personal reflection on identity, and the questioning of this identity. The writer allows the reader into a dream like environment where a life role is acted out as autobiographical narrative through appropriation and reference to the other. Theoretical sources include Walter Benjamin, Roland Barthes, Jacques Lacan and Joseph Kosuth. With reference to these sources, comparison is made between Jan Vermeer’s seventeenth century portraits of women and Bertolt Brecht’s early twentieth century epic theatre

Asymptotic analysis of multiscale approximations to reaction networks

A reaction network is a chemical system involving multiple reactions and chemical species. Stochastic models of such networks treat the system as a continuous time Markov chain on the number of molecules of each species with reactions as possible transitions of the chain. In many cases of biological interest some of the chemical species in the network are present in much greater abundance than others and reaction rate constants can vary over several orders of magnitude. We consider approaches to approximation of such models that take the multiscale nature of the system into account. Our primary example is a model of a cell's viral infection for which we apply a combination of averaging and law of large number arguments to show that the ``slow'' component of the model can be approximated by a deterministic equation and to characterize the asymptotic distribution of the ``fast'' components. The main goal is to illustrate techniques that can be used to reduce the dimensionality of much more complex models.Comment: Published at http://dx.doi.org/10.1214/105051606000000420 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

An Investigation of the Attitudes of School Leaders toward the Inclusion of Students with Disabilities in the General Education Setting

Public laws mandating access to free appropriate public education in the least restrictive environment have been in place for decades. Yet, many students with disabilities are still educated in segregated environments that fail to provide them with quality learning opportunities and supports. Inclusive practices have been implemented in many schools. However, the extent to which these practices meet the intent of the law depends on characteristics of the school leader. The purpose of this study was to examine the attitudes and perceptions of school leaders in a Southeast United States public school district relative to inclusion of students with disabilities in the general education setting. A self-reporting survey instrument entitled the Principals and Inclusion Survey was used to collect data from 138 school principals and assistant principals. Variables selected for study included demographic factors, training and experience, attitudes toward inclusion, and perceptions of the most appropriate placement for students with disabilities. Descriptive statistics, Pearson Correlations, and multiple regression were utilized to analyze the data and to answer six research questions posed by the researcher. Results from the analyses revealed that school leaders were limited in their training and experience relative to special education and inclusive practices and that their attitudes were slightly negative. While school leaders supported more inclusive placements for students with moderate disabilities, they perceived less inclusive placements were more appropriate for students with severe and profound disabilities. Results revealed a negative correlation between the training and experience and attitudes of school leaders. Results also revealed that the most appropriate placement for students with disabilities could be predicted from knowing the approximate number of students with IEPs that are included in regular education classrooms for at least 75% of their school day. Results strongly emphasize the need for quality training and experience for pre-service and practicing school leaders. Results of this study may assist school districts and university principal preparation programs in determining the type and the extent of coursework, professional development training, and practicum experiences required for pre-service and practicing school leaders to manage the daily special education challenges they face in their schools

Family food environment and dietary behaviors likely to promote fatness in 5-6 year-old children

Background: The family food environment (FFE) is likely to exert important influences on young children\u27s eating. Examination of multiple aspects of the FFE may provide useful insights regarding which of these might most effectively be targeted to prevent childhood obesity. Objective: To assess the associations between the FFE and a range of obesity-promoting dietary behaviors in 5&ndash;6-year-old children. Design: Cross-sectional study. Subjects: Five hundred and sixty families sampled from three socio-economically distinct areas. Measurements: Predictors included parental perceptions of their child\u27s diet, food availability, child feeding practices, parental modeling of eating and food preparation and television (TV) exposure. Dietary outcomes included energy intake, vegetable, sweet snack, savory snack and high-energy (non-dairy) fluid consumption. Results: Multiple linear regression analyses, adjusted for all other predictor variables and maternal education, showed that several aspects of the FFE were associated with dietary outcomes likely to promote fatness in 5&ndash;6-year-old children. For example, increased TV viewing time was associated with increased index of energy intake, increased sweet snack and high-energy drink consumption, and deceased vegetable intake. In addition, parent\u27s increased confidence in the adequacy of their child\u27s diet was associated with increased consumption of sweet and savory snacks and decreased vegetable consumption.&nbsp; Conclusion:&nbsp; This study substantially extends previous research in the area, providing important insights with which to guide family-based obesity prevention strategies.<br /

LCD 322 Disorders of Speech

LCD 322 is an undergraduate class that provides an overview of the symptoms, etiology, diagnosis, and treatment of various speech disorders including disorders of phonology/articulation, voice/resonance, fluency, swallowing, and speech impairment associated with neurological impairment. Speech disorders will be considered across the lifespan

Statistical approaches used to assess the equity of access to food outlets: a systematic review

Abstract: Background Inequalities in eating behaviours are often linked to the types of food retailers accessible in neighbourhood environments. Numerous studies have aimed to identify if access to healthy and unhealthy food retailers is socioeconomically patterned across neighbourhoods, and thus a potential risk factor for dietary inequalities. Existing reviews have examined differences between methodologies, particularly focussing on neighbourhood and food outlet access measure definitions. However, no review has informatively discussed the suitability of the statistical methodologies employed; a key issue determining the validity of study findings. Our aim was to examine the suitability of statistical approaches adopted in these analyses. Methods: Searches were conducted for articles published from 2000&ndash;2014. Eligible studies included objective measures of the neighbourhood food environment and neighbourhood-level socio-economic status, with a statistical analysis of the association between food outlet access and socio-economic status.Results Fifty four papers were included. Outlet accessibility was typically defined as the distance to the nearest outlet from the neighbourhood centroid, or as the numberof food outlets within a neighbourhood (or buffer). To assess if these measures were linked to neighbourhood disadvantage, common statistical methods included ANOVA, correlation, and Poisson or negative binomial regression. Although all studies involved spatial data, few considered spatial analysis techniques or spatial autocorrelation.Conclusions: With advances in GIS software, sophisticated measures of neighbourhood outlet accessibility can be considered. However, approaches to statistical analysis often appear less sophisticated. Care should be taken to consider assumptions underlying the analysis and the possibility of spatially correlated residuals which could affect the results.<br /

Employment status, residential and workplace food environments: associations with women\u27s eating behaviours

There remains a lack of consistent evidence linking food environments with eating behaviours. Studies to date have largely ignored the way different individuals interact with their local food environment and have primarily focussed on exposures within the residential neighbourhood without consideration of exposures around the workplace, for example. In this study we firstly examine whether associations between the residential food environment and eating behaviours differ by employment status and, secondly, whether food environments near employed women\u27s workplaces are more strongly associated with dietary behaviours than food environments near home. Employment status did not modify the associations between residential food environments and eating behaviours, however results showed that having access to healthy foods near the workplace was associated with healthier food consumption. Policies focused on supportive environments should consider commercial areas as well as residential neighbourhoods

Harnessing Marine Renewable Energy from Poole Harbour: Case Study

Global warming and its impact on our environment, society, economies and security is one of the fundamental concerns of our time. In response, the United Kingdom government has put in place a legally binding target of an 80% reduction in greenhouse gas emissions on 1990 levels by 2050. The United Kingdom will need to achieve a tenfold expansion of energy supply from renewable sources by 2020 to meet its share of the European Union renewable energy target. The marine and coastal environment’s renewable energy potential in Britain is high. It is estimated that it has 50% of the tidal energy, 35% of wave and 40% of wind resources in the European Union. Use of geothermal resources using heat pump technology is the least evolved sector, but in 2010 contributed to 0.7 TWh of energy and it is believed that non domestic heat pumps could contribute up to 22 TWh by 2020. In the Southwest of England, Poole Harbour has been recognised as a potential, highly predictable source of tidal and heat energy. Local groups are embarking on a feasibility study for harnessing this energy for the benefit of the community. The purpose of this article is to examine the potential conflict of interest between the laudable aims of promoting the use of renewable energy and of safeguarding ecosystems and their biodiversity. Using Poole Harbour as a case study, it will consider the environmental and economic costs and benefits of a Community Renewable Energy project (the Poole Tidal Energy Partnership) in the context of an area subject to a number of statutory and non-statutory designations to protect nationally and internationally important habitats and species. The paper identifies key environmental legislation, including spatial planning law and policy, which will facilitate exploring whether there is potential for reconciling what may be perceived as competing objectives for sustainable development