The ethics of workforce drug testing and HRM

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The pathogenicity and seasonal development of Gymnosporangium in Iowa

Seven species of the genus Gymnosporangium occur in Iowa, but only G. juniperi-virginianae, causing cedar-apple rust, and G. globosum, causing hawthorn rust, are common. The latter is of little economic importance. The epidemic of cedar-apple rust in 1928 caused an estimated loss of $200,000 in Iowa. Six to seven hours were required to produce abundant sporulation from air dry galls of G. juniperi-virginianae regardless of whether the period of soaking was 30 or 180 minutes. Newly-matured aecidiospores of G. juniperi-virginianae germinated to the extent of 54 percent in July. A lot was divided and the percentage of germination in the portion refrigerated at 5 to 13°C. increased rapidly for at least 22 days, while that in the portion held at room temperature for the same interval dropped to zero. At Shenandoah the interval between infection and first opening of aecidia of cedar-apple rust on Bechtel\u27s flowering crab was about 72 days. That for hawthorn rust on Crataegus mollis was about 81 days. Seedlings of red cedar were successfully inoculated using aecidiospores of G. juniperi-virginianae. Large differences in the number of galls on trees which had received similar treatments suggested a variation in disease resistance. The only appreciable germination of aecidiospores of G. globosum was obtained in November from diseased hawthorn leaves which had fallen to the ground and others which were refrigerated 41 days at 5°C. Differences in the degree of maturity reached by the cedar rusts are utilized in defining the relative susceptibility of their aecidial hosts. The percentage of leaf area covered by lesions of cedar-apple rust is recorded for 138 varieties of apples and 28 varieties of crabapples which were growing in nursery rows at Shenandoah during the years, 1928 to 1930. Aecidiospores were matured on only 30 percent of these hosts. The percentage of infected apple leaves seemed to vary roughly as the percentage. of diseased leaf area, but leafiness was not related to the amount of rust infection. These lines of evidence suggest that the period of susceptibility in leaves of susceptible varieties may be longer than that of resistant ones. Artificial inoculations show that Tolman and York Imperial varieties of apple are very susceptible to the strain of G. juniperi-virginianae from Morgantown, W. Va., but are resistant to other strains from Ames and Shenandoah, Iowa; Manhattan, Kan., and Cochrane, ,Vis. The results indicate the presence of physiologic specialization within the species. There is little evidence that the susceptibility of trees of one variety of apple may vary in different sections of the country. None of the observed varieties of apple or crabapple seem to be susceptible to G. globosum, in Iowa

Variation in parasite prevalence of kinosternid turtles across multiple hydration regimes.

Complex ecological interactions or physiological adaptations increasing immunity may limit parasite establishment in some host populations. The Madrean Sky Islands are regarded as a series of complex ecological systems rife with speciation and biodiversity. These desert ecosystems are subject to extreme abiotic fluctuation. The Sonoran mud turtle (Kinosternon sonoriense) is one of the only semi-aquatic turtle species capable of surviving in these habitats. Fecal analysis (n=217), blood smears (n=18), and dissection (n=4) were utilized to characterize the interpopulational variation in parasite prevalence among three closely-related Kinosternid species. These species occupy environments along a gradient with varying degrees of hydration and aquatic permanence. Kinosternon sonoriense populations occupying extreme habitats within the Madrean Sky Islands had a significantly lower parasite prevalence than yellow mud turtle (Kinosternon flavescens) populations (p = < 0.001, 95% CI [14.688, 153.306]) and eastern mud turtle (Kinosternon subrubrum) populations (p = 0.04762, 95% CI [0.814, 15.598]). White blood cell estimates among species were also significantly different (df= 2, p = < 0.05) providing further evidence that Kinosternon flavescens and Kinosternon subrubrum harbor larger parasite communities than Kinosternon sonoriense populations. Necropsy of Kinosternon sonoriense yielded no evidence of parasitism or pathology. Differential habitat use as well as the extreme environment itself likely contributes to these differences. However, further study should be conducted on parasite-host interactions in extreme environments to better understand the ecological mechanisms preventing parasite establishment in the Madrean Sky Islands. Understanding the ecology of Kinosternon sonoriense and the utilization of ephemeral aquatic habitats will aid in future conservation efforts in the Southwestern United States

Redefining the anthropomorphic animal in animation

The use of anthropomorphic animal characters is pervasive in animation, but there has been little examination of how and why these are created, and how a viewing audience understands them. This Practice-based PhD examines how a re-defining of anthropomorphic and zoomorphic representation might bring a new impetus to the use of animal imagery within contemporary animation practice. An initial stage of research was to define the term anthropomorphism both as a visual language within animation practice and in the wider contexts of scientific and philosophical discourse. Social and psychological aspects are discussed, recognising this form of hybrid representation throughout the development of human culture. Links with Human Animal Studies disciplines raised the question of relating anthropomorphism to negative aspects of anthropocentrism and this led to a second stage of the research that explores ways of working with anthropomorphism that do not promote an anthropocentric bias. This is firstly achieved through the devising of a new theoretical approach to character analysis that is based on the recognition of perceptual aesthetic and sensual animal qualities in human-led , animal-led and design-led anthropomorphic characters, rather than a reliance on conceptual symbolic referencing of human experiences, goals, and narratives. Moving into the practice and influence from historical animation work provides impetus for a move away from character and narrative based work. Experimental animation techniques are used to create rhythms and patterns of abstracted animal and human imagery. This new work is based on contemporary ecological ideas that discuss relationships between humans and animals as interconnected species, thus providing a second way of lessening of anthropocentric bias in the subject matter. Having a starting point of aesthetic and sensual responses to actual experiences with animals is an important factor and live action film is re-animated to create digitally manipulated rhythms of colour, texture, movement and sound. The practical research outcomes are animation samples that evidence the coming together of experimental digital techniques and contemporary ecological subject matter. An action research model was devised for the research to enable the integration of theory and practice, and reflection on theory and practice to have an important influence on the practical outcomes. The approach taken was dependent on experience as a creative practitioner and as a teacher helping others to develop a sustainable creative practice, in allowing an open and intuitive discovery of ideas from both theoretical and practical explorations to create a flow through the research. The combination of theoretical and practical research undertaken provides an impetus towards the creation of future animation work using an anthropomorphic visual language redefined as zooanthropomorphic animation . The submission includes outcomes of a written thesis and links to practical animation work

Preservation of long-term memory and synaptic plasticity despite short-term impairments in the Tc1 mouse model of Down syndrome

Down syndrome (DS) is a genetic disorder arising from the presence of a third copy of the human chromosome 21 (Hsa21). Recently, O’Doherty and colleagues in an earlier study generated a new genetic mouse model of DS (Tc1) that carries an almost complete Hsa21. Since DS is the most common genetic cause of mental retardation, we have undertaken a detailed analysis of cognitive function and synaptic plasticity in Tc1 mice. Here we show that Tc1 mice have impaired spatial working memory (WM) but spared long-term spatial reference memory (RM) in the Morris watermaze. Similarly, Tc1 mice are selectively impaired in short-term memory (STM) but have intact long-term memory (LTM) in the novel object recognition task. The pattern of impaired STM and normal LTM is paralleled by a corresponding phenotype in long-term potentiation (LTP). Freely-moving Tc1 mice exhibit reduced LTP 1 h after induction but normal maintenance over days in the dentate gyrus of the hippocampal formation. Biochemical analysis revealed a reduction in membrane surface expression of the AMPAR (α-amino-3-hydroxy-5-methyl-4-propionic acid receptor) subunit GluR1 in the hippocampus of Tc1 mice, suggesting a potential mechanism for the impairment in early LTP. Our observations also provide further evidence that STM and LTM for hippocampus-dependent tasks are subserved by parallel processing streams

Performance optimization for rotors in hover and axial flight

Performance optimization for rotors in hover and axial flight is a topic of continuing importance to rotorcraft designers. The aim of this Phase 1 effort has been to demonstrate that a linear optimization algorithm could be coupled to an existing influence coefficient hover performance code. This code, dubbed EHPIC (Evaluation of Hover Performance using Influence Coefficients), uses a quasi-linear wake relaxation to solve for the rotor performance. The coupling was accomplished by expanding of the matrix of linearized influence coefficients in EHPIC to accommodate design variables and deriving new coefficients for linearized equations governing perturbations in power and thrust. These coefficients formed the input to a linear optimization analysis, which used the flow tangency conditions on the blade and in the wake to impose equality constraints on the expanded system of equations; user-specified inequality contraints were also employed to bound the changes in the design. It was found that this locally linearized analysis could be invoked to predict a design change that would produce a reduction in the power required by the rotor at constant thrust. Thus, an efficient search for improved versions of the baseline design can be carried out while retaining the accuracy inherent in a free wake/lifting surface performance analysis

Impairments in motor coordination without major changes in cerebellar plasticity in the Tc1 mouse model of Down syndrome

Down syndrome (DS) is a genetic disorder arising from the presence of a third copy of human chromosome 21 (Hsa21). Recently, O’Doherty et al. [An aneuploid mouse strain carrying human chromosome 21 with Down syndrome phenotypes. Science 309 (2005) 2033–2037] generated a trans-species aneuploid mouse line (Tc1) that carries an almost complete Hsa21. The Tc1 mouse is the most complete animal model for DS currently available. Tc1 mice show many features that relate to human DS, including alterations in memory, synaptic plasticity, cerebellar neuronal number, heart development and mandible size. Because motor deficits are one of the most frequently occurring features of DS, we have undertaken a detailed analysis of motor behaviour in cerebellum-dependent learning tasks that require high motor coordination and balance. In addition, basic electrophysiological properties of cerebellar circuitry and synaptic plasticity have been investigated. Our results reveal that, compared with controls, Tc1 mice exhibit a higher spontaneous locomotor activity, a reduced ability to habituate to their environments, a different gait and major deficits on several measures of motor coordination and balance in the rota rod and static rod tests. Moreover, cerebellar long-term depression is essentially normal in Tc1 mice, with only a slight difference in time course. Our observations provide further evidence that support the validity of the Tc1 mouse as a model for DS, which will help us to provide insights into the causal factors responsible for motor deficits observed in persons with DS

Lower Bounds for Simplicial Covers and Triangulations of Cubes

We show that the size of a minimal simplicial cover of a polytope P is a lower bound for the size of a minimal triangulation of P, including ones with extra vertices. We then use this fact to study minimal triangulations of cubes, and we improve lower bounds for covers and triangulations in dimensions 4 through at least 12 (and possibly more dimensions as well). Important ingredients are an analysis of the number of exterior faces that a simplex in the cube can have of a specified dimension and volume, and a characterization of corner simplices in terms of their exterior faces

Control of cherry yellow-leaf on nursery stock

Yellow-leaf, caused by the fungus Coccomyces hiemalis Higgins, is the most prevalent and destructive cherry disease in Iowa, since it often causes premature defoliation of both nursery and orchard trees. Early defoliation in nursery stock results in decreased growth during the current and subsequent years, and precludes all possibility of forcing the trees into marketable size in one growing season. In the orchard, defoliation may decrease fruit bud formation and vegetative growth and increase the amount of winterkilling. All defoliated nursery stock must be held in the nursery row a second season, and even then many of the trees must be marketed at lower grades because of inferior size. Winterkilling in severely defoliated blocks is so common that yellow-leaf becomes the limiting factor in cherry culture