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

Criminological Theories: Nontraditional Voices and Themes.

Book review of Criminological Theories: Nontraditional Voices and Themes.” by Imogene L. Moyer

Substance abuse in rural and small town America

Alcohol abuse exceeds illicit drug abuse in rural America and is a serious problem among rural youth, as highlighted here. The report also confirms that the abuse of stimulants, including methamphetamine, is high among certain rural populations, particularly among the rural unemployed

Comparing teen substance use in northern New Hampshire to rural use nationwide

Using data administered in 2011 from the Carsey Institute’s Coös Youth Study and the National Survey on Drug Use and Health, this brief compares teen substance use patterns in New Hampshire’s most rural county to patterns among rural youth nationwide. Author Karen Van Gundy reports that about half of the teens in Coös County and in rural areas nationwide reported using any substance in the previous year. Alcohol use was reported most often, followed by tobacco or marijuana, and other illicit substances. Rural boys nationwide reported using tobacco at significantly higher rates than Coös boys and girls and rural girls nationwide, while Coös boys reported significantly higher rates of frequent use (that is, three or more times weekly) of marijuana or any substance than Coös girls and rural boys and girls nationwide. Previous research has shown that teens who use marijuana are more “stressed out,” and that such stress can increase their risk for other illicit drug abuse in young adulthood. Van Gundy suggests that substance abuse policies and practices that prevent, reduce, or buffer the stresses faced by Coös teens can also enhance their general well-being as they make the transition to adulthood

Mental health among northern New Hampshire young adults: depression and substance problems higher than nationwide

This brief uses data on depressive and substance abuse symptoms from two surveys administered in 2011—the Coös Youth Study and the National Survey on Drug Use and Health—to compare mental health patterns among young adults in Coös County, New Hampshire, to patterns among rural young adults nationwide. The analyses focus on 214 Coös young adults and 1,477 young adult respondents, ages 18 to 21, who were living in non-metropolitan areas in 2011 and who provided usable data on depressive and substance abuse symptoms. Author Karen Van Gundy reports that Coös County young adults are more likely than rural young adults nationwide to suffer from symptoms of depression and substance abuse, and these patterns vary by sex. Coös young women tend to experience more depressive symptoms than their national counterparts, and Coös young men tend to experience more substance abuse symptoms than their national counterparts. Van Gundy concludes that programs fostering community attachment could lessen adult substance abuse in Coös County and that combined or co-occurring symptoms of depression and substance abuse in Coös County require careful consideration

Sound propagation and force chains in granular materials

Granular materials are inherently heterogeneous, leading to challenges in formulating accurate models of sound propagation. In order to quantify acoustic responses in space and time, we perform experiments in a photoelastic granular material in which the internal stress pattern (in the form of force chains) is visible. We utilize two complementary methods, high-speed imaging and piezoelectric transduction, to provide particle-scale measurements of both the amplitude and speed of an acoustic wave in the near-field regime. We observe that the wave amplitude is on average largest within particles experiencing the largest forces, particularly in those chains radiating away from the source, with the force-dependence of this amplitude in qualitative agreement with a simple Hertzian-like model of particle contact area. In addition, we are able to directly observe rare transient force chains formed by the opening and closing of contacts during propagation. The speed of the leading edge of the pulse is in quantitative agreement with predictions for one-dimensional chains, while the slower speed of the peak response suggests that it contains waves which have travelled over multiple paths even within just this near-field region. These effects highlight the importance of particle-scale behaviors in determining the acoustical properties of granular materials

Improving Community Adaptation Outcomes for Youth Graduating from Residential Mental Health Programs: A Synthesis Review (FULL REPORT)

The focus of this synthesis review was to understand the capacity of systems of care and integrated program models to foster successful community adaptation for children and youth graduating from children\u27s residential mental health treatment

NE- 165 Case Study : LEANER PORK: Can New Sector Linkages Be Formed?

A more demanding and evolving consumer is creating change in the market for pork and many working within the industry are predicting opportunities for leaner products. However, leaner pork enthusiasts also are frustrated by the established industry food chain that offers little incentive for modification. Modification would require change on the part of genetic suppliers, commercial producers, packers and processors, and retailers. However, many of these food chain participants traditionally have not collaborated with others in the sector. Yet the establishment of these new linkages may be key to the success of a leaner pork industry. This case study documents several of the activities currently occurring within the leaner pork industry and explores new linkages which may be critical in the future. Currently, genetic suppliers are struggling with short-term needs of producers, while attempting to look at the long-term demands of consumers. Hog producers have been profitable and lack incentives to alter practices which would produce leaner animals. Packers are interested in efficiently running large scale operations with large quantities of low cost meat. Retailers struggle with labeling inconsistencies and a low cost mentality that make it difficult to market leaner pork in the meatcase. Leaner pork enthusiasts are making strides to overcome the disadvantages found in the traditional system. Some genetic suppliers are now working with packers to determine animal quality beyond the producer's feedlot. Some packers are creating incentive programs that pay producers for leaner quality. These lean incentive programs may become more attractive for packers and producers if new technologies measuring lean become less prohibitive for larger operations. Many packers are moving into branded products, resulting in incentive programs for producers who supply animals with the desired quality. Overall, these efforts have remained a small portion of total pork industry activities.Agribusiness, Livestock Production/Industries,

Improving Community Adaptation Outcomes for Youth Graduating from Residential Mental Health Programs: A Synthesis Review (SUMMARY)

The focus of this synthesis review was to understand the capacity of systems of care and integrated program models to foster successful community adaptation for children and youth graduating from children\u27s residential mental health treatment

Improving Community Adaptation Outcomes for Youth Graduating from Residential Mental Health Programs: A Synthesis Review (EXECUTIVE SUMMARY)

Based on results from a synthesis review, this Executive Summary highlights elements of a proposed integrated program configuration that shows a demonstrated capacity to foster successful community adaptation for children and youth graduating from children\u27s residential mental health programs. An expanded discussion of the synthesis review findings is available in both a full length synthesis report and summary version