354 research outputs found
FIGURE 14 in Three new ghost moths of the genus Oxycanus Walker, 1856 from Australia (Lepidoptera: Hepialidae)
No full textFIGURE 14. Inman Valley, Fleurieu Peninsula, South Australia. Highly degraded habitat of Oxycanus ephemerous sp. n., ©Ethan P. Beaver.Published as part of Beaver, Ethan P., Moore, Michael D., Velasco-Castrillón, Alejandro & Stevens, Mark I., 2020, Three new ghost moths of the genus Oxycanus Walker, 1856 from Australia (Lepidoptera: Hepialidae), pp. 351-374 in Zootaxa 4732 (3) on page 371, DOI: 10.11646/zootaxa.4732.3.1, http://zenodo.org/record/366712
Management of Exercise-Induced Bronchoconstriction
No full textExercise-induced bronchoconstriction (EIB) is a common clinical manifestation of asthma, occurring in 70% to 80% of asthmatics. Evidence suggests that exercise and the ensuing bronchoconstriction do not contribute to a worsening of asthmatic inflammation. Asthmatics should not be discouraged from exercising, and, with adequate management, most patients should be able to exercise regularly with only minor symptoms. The first step in the management of patients with EIB should be to obtain optimum control of the underlying asthma, often requiring regular treatment with inhaled steroids. Regular treatment with inhaled corticosteroids usually reduces the extent of EIB by 50% or more. Frequently, despite optimal management of the underlying asthma, patients develop EIB symptoms requiring additional treatment. Short and long acting inhaled beta2-agonists are highly effective at reducing the magnitude of EIB, although there are concerns that the extent of protection diminishes during periods of regular use of these agents. Inhaled cromolyn and nedocromyl are effective at reducing the extent of EIB in some patients, although this protection does not extend beyond 2 to 3 h after treatment. The recently developed leukotriene receptor antagonists are effective at reducing the extent of EIB by 40% to 70%, and have the advantage that this protection lasts throughout the day and does not appear to diminish with regular use. Other agents, including anticholinergics and antihistamines, have been shown to offer partial protection against EIB, suggesting the possibility of using a combination treatment to manage some patients’ symptoms. Finally, there is encouraging evidence suggesting that modifications of the pattern of exercise can markedly reduce the extent of EIB
Topological chaos and chaotic mixing of viscous flows
No full textSince it is difficult or impossible to generate turbulent flow in a highly viscous fluid or a microfluidic system, efficient mixing becomes a challenge. However, it is possible in a laminar flow to generate chaotic particle trajectories (well-known as chaotic advection), that can lead to effective mixing. This dissertation studies mixing in flows with the limiting case of zero Reynolds numbers that are called Stokes flows and illustrates the practical use of different theories, namely the topological chaos theory, the set-oriented analysis and lobe dynamics in the analysis, design and optimization of different laminar-flow mixing systems.
In a recent development, the topological chaos theory has been used to explain the chaos built in the flow only based on the topology of boundary motions. Without considering any details of the fluid dynamics, this novel method uses the Thurston-Nielsen (TN) classification theorem to predict and describe the stretching of material lines both qualitatively and quantitatively. The practical application of this theory toward design and optimization of a viscous-flow mixer and the important role of periodic orbits as "ghost rods" are studied.
The relationship between stretching of material lines (chaos) and the homogenization of a scalar (mixing) in chaotic Stokes flows is examined in this work. This study helps determining the extent to which the stretching can represent real mixing. Using a set-oriented approach to describe the stirring in the flow, invariance or leakiness of the Almost Invariant Sets (AIS) playing the role of ghost rods is found to be in a direct relationship with the rate of homogenization of a scalar. The mixing caused by these AIS and the variations of their structure are explained from the point of view of geometric mechanics using transport through lobes. These lobes are made of segments of invariant manifolds of the periodic points that are generators of the ghost rods.
A variety of the concentration-based measures, the important parameters of their calculation, and the implicit effect of diffusion are described. The studies, measures and methods of this dissertation help in the evaluation and understanding of chaotic mixing systems in nature and in industrial applications. They provide theoretical and numerical grounds for selection of the appropriate mixing protocol and design and optimization of mixing systems, examples of which can be seen throughout the dissertation.Ph. D
Shoot and stalk dynamics and the yield of sugarcane crops in tropical and subtropical Queensland, Australia
No full textYield constraints have become an important feature of sugarcane farming systems in Australia, with significant yield increases obtainable by manipulating farming system components (e.g. crop rotation). However, to identify key crop targets for new farming systems, an improved understanding of the physiological mechanisms mediating these yield responses is required. Data from experiments investigating impacts of crop rotation, plant population, tillage and trash management have been analysed to determine the impact of treatments on shoot and stalk dynamics and crop yield.
Crop rotation or soil fumigation resulted in significantly improved crop establishment, with production of greater numbers of both primary and higher order shoots. Manipulation of soil N status in these experiments had limited effect on the initiation of secondary tillers, regardless of whether the N was the result of a rotation treatment or of fertiliser N applications within a common rotation history. In all cases, effects of N were minimal compared to those of other components of soil health affected by fumigation (primarily detrimental soil biota) and rotation (differing elements of physical and chemical fertility and soil biota). Survival of tillers until final harvest was strongly influenced by the population density of established primary shoots and the growing conditions during the latter part of the growing season. Reduced water stress and application of N fertiliser near the time of maximum tiller numbers increased tiller survival.
The relative importance of final stalk population density and individual stalk dry mass to variation in yield in each experiment, varied widely. The cultivar Q117, which was used in experiments in northern regions of Mackay, Burdekin and Tully, achieved relatively low final stalk densities (4–8 stalks m−2) and yield variation in these experiments was primarily due to treatment effects on this attribute. Experiments in the south at Bundaberg used a number of cultivars (Q124, Q141, Q188) which all achieved higher stalk population densities (9–12 stalks m−2) with yield variation primarily affected by individual stalk mass.
Experiments designed to broaden the range of plant densities tested revealed a negative relationship between individual stalk mass and stalk population density. These data show that treatments that increase stalk population densities at harvest without also increasing rates of dry matter accumulation during stalk filling are unlikely to increase yields. Improvements in soil health afforded by crop rotation and soil fumigation deliver yield benefits by achieving both higher population densities and heavier stalks
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A narrative policy framework analysis of food assistance programs in Oregon
No full textWhile policies like the Supplemental Nutrition Assistance Program (SNAP) and National School Lunch Program (NSLP) are complex, we can leverage policy narratives to order that complexity and help distill meaning. We can also examine food policy narratives to help identify policy solutions for families navigating poverty and subsistence living. This research investigates SNAP and NSLP policy narratives using two theoretical approaches. First, I leverage the Narrative Policy Framework (NPF) which provides the theoretical tools to describe and compare the structure of stakeholder food stories and identify narrative characters, plots, and morals of the story. Secondly, I employ Cultural Theory (CT) to help understand how people systematically make sense of the content of their stories. Together, the NPF and CT allow me to examine how the structure and content of food policy stories vary, and what this variation means to the policy process.
Paper 1 leverages participant observation, qualitative interviews, and survey data to explore Corvallis, Oregon NSLP policy, contrasting local and national policy perspectives to identify distinct food policy narratives among Corvallis, Oregon stakeholders and across cultural groups. This paper’s main findings were a predominantly egalitarian worldview among Corvallis stakeholders whose narratives feature children as victims, with community institutions and advocates in the roles of the heroes and/or villains. Sustainability and the value of market forces were also identified as key themes in local and national school lunch narrative plots and morals.
Paper 2 employs similar methods and analysis tools used for paper 1 but includes an expanded sample frame to include SNAP program beneficiaries and administrators from Lincoln, Benton, and Linn, Oregon counties. Paper 2 is an investigation of policy narratives surrounding the Covid-19 SNAP temporary Emergency Allotments (EAs) policy termination. I define this policy termination as a ‘policy cliff,’ as it is the time at which the economic stimulus abruptly ended. Key findings include stakeholders with a shared egalitarian-leaning worldview and how the expanded investment in food programs during the Covid-19 public health emergency helped reduce food insecurity and aid families navigating poverty. Another key finding was that program beneficiaries and administrators faced the policy cliff together, facing down the incoming crisis with various motivations, perspectives, and tools which impacted policy learning.
Paper 3 builds on the data from papers 1 and 2, using a similar theory and data analysis method. I applied a lens of rural poverty and food insecurity to student families, with the goal of qualifying and quantifying the rural and non-rural narratives observed in my field research and interviews across ODHS District 4. Findings suggest that CT worldviews expressed by both rural and non-rural interviewees are profoundly egalitarian. Thematic variations in the egalitarian narratives emerged using a CT weighted measure and in discussions of geographic proximity to food program access and distance to full-service grocery stores.
Together these papers contribute to the study of food-focused social policy narratives, comparing a sample population of SNAP and NSLP program advocates, beneficiaries, and administrators from across Oregon Department of Human Services (ODHS) District 4, spanning Lincoln, Benton, and Linn counties. My research goals were exploratory and descriptive. Resultant data may be used to inform future ODHS and school district policy processes
Time-of-flight mass spectrometry with KeV and MeV projectiles using coincidence counting
No full textTypescript (photocopy)VitaMajor subject: ChemistryThe goal of this study was to explore sample-projectile interactions by examining secondary ion (SI) yields in an event-by-event impact and detection mode. Cluster secondary ion mass spectrometry (SIMS) was evaluated in comparison to plasma desorption mass spectrometry (PDMS) and monoatomic SIMS. A cluster ion source was designed based on the spontaneous desorption (SD) process. The parameters affecting the SD were studied to optimize the cluster source performance. These factors were extraction grid vs. aperture, aperture size, source bias, source distance, and time. Under optimized SD conditions signal-to-noise ratios (S/N) up to approximately 27 were obtained for the production of CsI cluster ions. The ions of interest from the source were I' and (CsI)[n]I' clusters (where n is the cluster order). For our source a 3 mm gridless aperture 8 mm from the source foil produced the highest signal-to-noise ratio at 18 kV on the source. A signal-to-noise maximum was reached after the sample was biased for 12 hours. The SI yields from organic targets were compared for monoatomic keV ions, MeV ions (252Cf fission fragments), and polyatomic keV ions. The energy range of the clusters used was 18 to 27 keV. This comparison was made by calculating secondary ion yields for the molecular ions from a given sample. The organic samples used were epinephrine, ����-aminobutyric acid, phenylalanine, and valine. For cluster bombardment secondary ion yields ranged from 0.53% for epinephrine to 3.45% for phenylalanine. These yields are less than the molecular ion yields from PDMS which ranged from 3.09% for epinephrine to 7.00% for phenylalanine. The secondary ion yields for monoatomic bombardment were 0.05% for epinephrine and 0.29% for phenylalanine. The higher yields observed with cluster primary ions are attributed to an enhancement effect related to the number of constituents in a cluster..
Una lamentación de Jeremías compuesta en el siglo XVI para el uso de la Catedral de México. Anales del Instituto Nacional de Antropología e Historia. Num. 47 Tomo XVIII (1965) Sexta Época (1939-1966)
No full textBal y Gay, J., ed. Tesoro de la Música Polifónica en México, 1, El Códice del Convento del Carmen, Instituto Nacional de Bellas Artes. México, 1952.Barwick, S. Sacred Vocal Polyphony in Early Colonial Mexico. Harvard University Ph. D. dissertation,1949.Barwick, S. The Franco Codex, Transcription and Commentary. Southern Illinois University Press, 1965.Estrada, J. Clásicos de Nueva España: Ensayo histórico sobre los Maestros de Capilla de la Catedral de México, Scola Cantorum. Morelia, 1945.Saldívar, G. Historia de la Música en México: Epocas Precortesiana Colonial. México. 1934.Spell, L. M. Music in the Cathedral of Mexico in the Sixteenth Century. The Hispanic American Review, Agosto de 1946.Stevenson, R. Music in Mexico, A Historical Survey. New York, 1952
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