ACTH and polymorphisms at steroidogenic loci as determinants of aldosterone secretion and blood pressure

The majority of genes contributing to the heritable component of blood pressure remain unidentified, but there is substantial evidence to suggest that common polymorphisms at loci involved in the biosynthesis of the corticosteroids aldosterone and cortisol are important. This view is supported by data from genome-wide association studies that consistently link the CYP17A1 locus to blood pressure. In this review article, we describe common polymorphisms at three steroidogenic loci (CYP11B2, CYP11B1 and CYP17A1) that alter gene transcription efficiency and levels of key steroids, including aldosterone. However, the mechanism by which this occurs remains unclear. While the renin angiotensin system is rightly regarded as the major driver of aldosterone secretion, there is increasing evidence that the contribution of corticotropin (ACTH) is also significant. In light of this, we propose that the differential response of variant CYP11B2, CYP11B1 and CYP17A1 genes to ACTH is an important determinant of blood pressure, tending to predispose individuals with an unfavourable genotype to hypertension

Polyenamines from aromatic diacetylenic diketones and diamines

The synthesis and characterization of several polyenamine ketones are discussed wherein conjugated diacetylenic diketones and aromatic diamines are used as a route to the formation of high molecular weight polyenamine ketones which exhibit good mechanical properties and can be cast into creasible films. Typical polymerization conditions involved the reaction of stoichiometric amounts of 1,4- or 1,3-PPPO and a diamine at 60 to 130 C in m-cresol at (w/w) solids content of 8 to 26% for a specified period of time under a nitrogen atmosphere. Novel polyenamine ketones were prepared with inherent viscosities as high as 1.99 dl/g and tough, clear amber films with tensile strengths of 12,400 psi and tensile moduli of 397,000 psi were cast from solutions of the polymers in chloroform. In most cases, the elemental analyses for the polyenamine ketones agree within + or - 0.3% of the theoretical values

Effects of plant-soil interactions on grassland carbon dynamics in a changing world

Doctor of PhilosophyDivision of BiologyJohn M. BlairPlants are a major conduit through which carbon moves between the atmosphere and the terrestrial biosphere. The organic inputs from plants provide energy to soil microbes which fuels microbial extracellular enzyme production. Soil microbial activity determines the proportion of plant organic inputs that remains stored in soil as organic matter or is mineralized and released back into the atmosphere as carbon dioxide. Plant-soil interactions are, therefore, a critical driver of terrestrial carbon cycling. We live in an era of human-driven change which affects every aspect of ecosystem functioning, so it is critical to understand how different global change factors modulate the plant-soil interactions that influence carbon cycling. In this dissertation I focus on the effects of four specific global change factors on plant-soil interactions in a tallgrass prairie ecosystem: (1) land-use change (i.e., fire suppression and bison removal), (2) woody encroachment, (3) plant invasion, and (4) nutrient enrichment. The overall conclusion from my dissertation research is that all four of these global change factors alter plant-soil interactions in ways that change the storage or turnover of soil carbon. First, long-term fire suppression and/or bison exclusion increases soil C content over time. This change in soil C content is associated with an increase in woody plants in the case of fire suppression or an increase in the dominance of warm-season grasses in the case of bison exclusion under a frequent fire regime. Second, potential C mineralization rates under clonal woody shrubs is higher when the microbial community is decomposing proportionally more shrub-derived organic matter, suggesting that the rate of soil C flux may be dependent on how long the soil has been occupied by woody species. Third, the invasive grass Bromus inermis induces legacy effects on soil microbial community composition and soil organic matter (SOM) decomposition rates. These legacy effects persist for at least six months post-invasive grass removal. Finally, phosphorus fertilization stimulates the rate of SOM decomposition in soil undergoing woody encroachment, but nitrogen fertilization does not. Collectively, these results suggest that the effects of many global change factors on carbon cycling is dependent on spatiotemporal context and historical factors. Additionally, since each of the global change factors I studied affected carbon cycling independently, it will be important to study the combined effects of multiple global change factors acting simultaneously in order to better predict how carbon cycles through terrestrial ecosystems as the world continues to change

Analyzing the Carbon Footprint of an Intravitreal Injection

Purpose: To estimate the carbon footprint of a single intravitreal injection in a hospital-based intravitreal service. Methods: Greenhouse gas emissions attributable to the delivery of an intravitreal injection were calculated using a hybrid lifecycle analysis technique. Data were collected regarding procurement of materials, patient travel, and building energy use. Results: Carbon emissions associated with a single intravitreal injection, excluding the anti-VEGF agent, were 13.68 kg CO2eq. This equates to 82,100 kg CO2eq annually for our service. Patient travel accounted for the majority of emissions at 77%, with procurement accounting 19% for and building energy usage for 4% of total emissions. The omission of items considered dispensable from injection packs would reduce carbon emissions by an estimated 0.56 kg per injection – an annual saving of 3,360 kg CO2eq for our service. Similar savings, if extrapolated to a country the size of the United Kingdom, could yield annual carbon savings of 450,000 kg CO2eq. For context, a single one-way economy transatlantic flight produces 480 kg CO2eq per person. Conclusion: Wasteful practice in healthcare increases greenhouse gas production and drives climate change. The healthcare sector should be a leader in sustainable practice promotion and changes to high volume procedures have the largest impact on emissions. Long-acting agents offer the greatest future potential for meaningful reductions

Discharge coefficients of flat-fan nozzles

The discharge coefficient (Cd) is a measure of how much of the pressure energy of a nozzle is converted into kinetic energy. With the discharge coefficient known, the exit velocity of the liquid sheet from the nozzle can be calculated from the pressure. It is important to be able to accurately calculate this nozzle exit velocity for use in initializing computational simulations such as AGDISP or CFD. The objective of this work was to measure the discharge coefficients for different types of flat-fan nozzles. In this work, a phase-Doppler interferometer was used to measure the exit velocity for standard, pre-orifice, and air-induction flat-fan nozzles, for rated sizes from 01 to 06, at pressures from 1 to 6 bar. From these velocities, discharge coefficients were calculated. The standard flat-fan nozzles had the highest discharge coefficients, while the air-induction nozzles had the lowest discharge coefficients. For a fixed type of nozzle design, the discharge coefficient increased slightly with the rated flow rate. The discharge coefficient decreased slightly with increasing pressure for a given nozzle. Much of the differences in droplet size for different types of nozzles can be explained by atomization theory as a result of the differences in discharge coefficients for the different nozzle designs

Polyimide-Clay Composite Materials for Space Application

The introduction of nanometer-sized clay particles into a polyimide matrix has been shown to enhance the physical properties of specific polymer systems. The clay comprises large stacked platelets of the oxides of aluminum and silicon. These sheets have long dimensions on the order of tenths of a micrometer and thicknesses of several nanometers. Homogeneous dispersion of the clay platelets in the polymer matrix is necessary to achieve those enhancements in polymer properties. Natural montmorillonite with the empirical formula Na0.33Mg0.33Al1.67(OH)2(Si4O10) contains exchangeable inorganic cations. The clay lamellae stack together with the positive sodium ions situated between the surfaces of the individual sheets to balance negatively charged oxygen atoms that are on the surfaces of the sheets. These surface charges contribute to strong electrostatic forces which hold the sheets together tightly. Exfoliation can be accomplished only with unusual measures. In preparing clay nanocomposites, we have taken two steps to try to reduce these interlamellar forces in order to promote the separation (exfoliation) of the sheets and the dispersion of the individual clay particles throughout the organic polymer matrix. In the first step, some of the surface Na(+) ions are replaced with Li(+) ions. Unlike sodium cations, the lithium cations migrate into the interior of the lamellae when the system is heated. Their departure from the surface reduces the surface charge and therefore the attractive forces between the sheets. The loss of alkali metal cations from the surface can be measured as the cation exchange capacity (CEC) of the clay. For example, we found that the CEC of montmorillonite clay was reduced by almost two thirds by treating it with lithium ions and heating to 250 C for 24 hr. Lesser heating has a smaller effect on the CEC. X-ray diffraction measurements show that the d-spacing decreased from ca. 1.34 to 0.97 nm, apparently a consequence of a collapse of the clay layers. We observed that the d-spacing can be varied by altering the heat treatment. In the second part of our effort to reduce the interlamellar forces, the remaining inorganic surface cations were replaced by the trimethylphenylammonium ion (TMPA), the biphenyltrimethylammonium ion (BTMA), or the tetraphenylphosphonium ion (TPP)

An American Beauty Rose

https://digitalcommons.library.umaine.edu/mmb-vp/1019/thumbnail.jp

A kinematic analysis of the role of the upper-extremities during vertical jumping

Over the last two decades, plyometric training has been extensively adopted by athletes, coaches and sport scientists with a primary aim to improve vertical jump height. The focus of these plyometric programmes has been to train the lower-extremity musculature in order to enhance jump performance. However, the lower-extremities are not the only contributing factor to vertical jump performance, as the use of an arm-swing during vertical jumping has also been shown to contribute to achieving maximum vertical jump height, yet training programmes for improving the arm-swing during the vertical jump are limited. Therefore, the primary aim of this thesis was to examine the full arm-swing mechanics during vertical jumping, and to then develop and assess the suitability of an upper-extremity plyometric programme for increasing both arm-swing kinematics and jump height. Firstly, a descriptive study was conducted to assess if an arm-swing countermovement was utilised during the vertical jump, which was deemed the prerequisite for using plyometric training to improve the arm-swing. Then an experimental study was conducted comparing vertical jumps performed with and without an arm-swing countermovement. The results showed that jumps performed with an arm-swing countermovement significantly increased mean peak shoulder angular velocity (ω) (+67.5 deg·s-1) and mean jump height (+ 6.2 cm) when compared to jumps performed using no arm-swing countermovement. During the final chapter of this thesis, a group of elite basketball players volunteered to participate in upper-extremity plyometric training aimed at increasing vertical jump height by training only the upper-extremities. Vertical jump height and full body kinematics were analysed using a 3 dimensional (3D) motion capture system, and key kinematic jump variables and various arm-swing performance measurements were collated both before and after a 4 week upper-extremity plyometric intervention. The use of upper-extremity plyometric training significantly increased the mean jump height (+ 7.2 cm), mean peak shoulder ω (+ 167.1 deg·s-1), mean peak frontal shoulder ω (+ 121 deg·s-1) and mean active range of motion at the shoulder joint (+ 5.3°), when compared to a control group. Furthermore, the use of a large active range of motion armswing during the arm-swing countermovement was shown to be the preferred arm-swing condition for increasing arm-swing kinematics. The increase in arm-swing kinematics and jump height after the 4 week upper-extremity plyometric programme was attributed to the participants’ improved ability to use the stretch-shortening cycle, elastic energy transfer system and stretch reflex system. Therefore, the use of upper-extremity plyometric exercises as part of a training regime for improving vertical jump performance should be advocated

Developing strategic partnerships through a sustainability enrichment week

This paper describes the development of a mini-module focused on sustainability and timber engineering as a component of a strategic partnership designed to broaden Transnational Education, increase staff/student mobility, and further develop industry and community links within two universities. Edinburgh Napier University (ENU) draws students from around the world and is internationally recognised for timber construction and wood science. The New Model Institute for Technology and Engineering (NMITE) is a new higher education provider in England pioneering an innovative approach to engineering education integrating business, engineering, the liberal arts, and professional skills. ENU and NMITE leveraged these strengths to develop a strategic partnership that brings together staff, students, industry, and the community for opportunities that create impact beyond traditional learning approaches. This can be seen through the development of a Sustainability Enrichment Week hosted by NMITE’s Centre for Advanced Timber Technology (CATT) and attended by ENU Master’s in Environmental Sustainability students. Students investigated interfaces between buildings, humans, and nature through experiential learning based around the construction of the CATT building, which has been developed as a Living Lab. Each day featured activities aligned to identified learning outcomes and was themed around one of five sustainability competencies: systems thinking, values thinking, strategic thinking, future thinking, and collaboration. The Sustainability Enrichment Week also served as a trial for a short course soon to be offered as part of a Timber Technology, Engineering, and Design programme. This project could be a model for other universities seeking to create similar strategic partnerships and learning experiences