The Quest for the Ideal Fluorescent Cell Stain

Undergraduate Applie

A New Outcrop of the Rockville Conglomerate

During the summer of 1953, an outcrop of ferruginous pebble conglomerate was found in central Jones county, Iowa. This outcrop is located about three miles north of the town of Olin, along the eastern edge of Iowa Highway 38 between Olin and the junction of Highways 38 and 64. It is near the center of the SE¼ of section 25, T. 84 N., R. 3W. (Jackson Township) Jones County. Topographically, it occurs about midway up the gentle north side of the valley of the Wapsipinicon River. The rock at this locality extends horizontally for about thirty feet and has about five feet of its thickness exposed. Along the tops of the exposed bedding planes, weathering has produced a mottled black-gray color. On fresh surfaces and on some of the vertical fractures, the rock is light-gray, pale yellow-brown, or dull-red in color

Attention Function Structure of Older and Younger Adult Drivers

Groups of younger (n=49, M age = 21.7 years) and older (n=52, M age = 73.0 years) adults performed computer-based cognitive tests and simulated driving. Results from the cognitive tests were submitted to Principal Components Analysis (PCA) and 6 components were extracted that explained more than 77% of the variance. The components were labeled speed, divided, sustained, executive, selective/inhibition, and visual search in descending order of amount of variance explained. The component scores were used to predict simulated driving performance. Hierarchical step-wise regressions were computed with driving performance as the criterion, and age group (forced) and the component scores (step-wise) as predictors. Results showed that the speed and divided components were more likely to explain additional driving performance variance beyond age group than the other components

A Massive Chert Bed in the Hopkinton Formation and an Associated Boulder Train Near Strawberry Point, Clayton County, Iowa

Feulner, while mapping the bedrock of Clayton county during the summer of 1951, observed numerous large chert erratics scattered over the landscape west of Strawberry Point. These erratics lie near the edge of the Iowan drift plain just south of the northfacing Niagaran escarpment, which is formed by the erosion of Silurian rocks

Attention Factors Compared to Other Predictors of Simulated Driving Performance Across Age Groups

Groups of young, middle-aged, and older adults performed a battery of computer-based attention tasks, the UFOV® and neuropsychological tests, and simulated low-speed driving in a suburban scenario. Results from the attention tasks were submitted to Maximum Likelihood factor analysis and 6 factors were extracted that explained more than 57% of the task variance. The factors were labeled speed, switching, visual search, executive, sustained, and divided attention in descending order of amount of task variance explained. The factor scores were used to predict simulated driving performance. Step-wise regressions were computed with driving performance as the criterion, and age, sex and the factor scores, the UFOV® scores, or the neuropsychological test scores as predictors. Results showed that the perceptual-motor speed and divided attention measures from the UFOV® and attention battery were more likely to explain driving performance variance than the neuropsychological tests

The Distribution of Climatic Factors in Iowa and Their Influence on Geomorphic Processes

This paper undertakes to evaluate effects of climate upon geormorphic processes in Iowa. Iowa\u27s climate is described as humid continental long summer, with three-fourths of the annual precipitation falling between the end of March and the beginning of October. In almost all climatic factors, the variation trends or changes from the north-northwest toward the south-southeast. Using the two parameters of mean annual temperature and mean annual rainfall for 119 stations in Iowa, a scattergram was constructed. Statistical analyses of the data suggest the presence of three microclimatic zones or regions in Iowa--northern, central, and southern. Comparisons of climatically controlled aspects of erosion and weathering showed that (1) drainage composition has had greater development in the south; (2) climatic factors affect the distribution and transportation of the dissolved and suspended load in streams: (3) soils of similar type and origin are more mature and have undergone more leaching of potassium, magnesium, and phosphorus in the southeast than in the northwest; (4) employment of the universal soil loss equation indicates that more soil is likely to be removed per acre by erosion in the southeast than in the northwest. In comparing degrees of erosion and weathering between the three microclimatic regions, slight differences become apparent, indicating that in terms of climatic geomorphology, these regions are distinct

Cotton fiber: a powerful single-cell model for cell wall and cellulose research

Cotton fibers are single-celled extensions of the seed epidermis. They can be isolated in pure form as they undergo staged differentiation including primary cell wall synthesis during elongation and nearly pure cellulose synthesis during secondary wall thickening. This combination of features supports clear interpretation of data about cell walls and cellulose synthesis in the context of high throughput modern experimental technologies. Prior contributions of cotton fiber to building fundamental knowledge about cell walls will be summarized and the dynamic changes in cell wall polymers throughout cotton fiber differentiation will be described. Recent successes in using stable cotton transformation to alter cotton fiber cell wall properties as well as cotton fiber quality will be discussed. Futurec prospects to perform experiments more rapidly through altering cotton fiberwall properties via virus-induced gene silencing will be evaluated

An Examination of the Relationship Between Attention Profiles and Simulated Driving Performance

This study examined whether attention profiles from a computerized test battery relate to simulated driving performance. Five attention abilities were examined in the study: sustained, divided, selective, switching, and scanning. Participants completed eight tasks in a computer-based test battery and four driving scenarios designed to tap the same attention abilities. Physiological measures were collected during the test battery and the driving scenarios. Principal components analysis (PCA) with varimax rotation extracted seven components from the test battery, including the five proposed abilities along with speed and orienting components. Component scores were used as predictors of simulated driving performance in stepwise regressions and explained a significant proportion of variance (ranging from 7% - 26%) for most measures of driving performance. The speed, visual search, and divided attention components appeared as significant predictors more often than did the sustained, switching, orienting, and selective components. When physiological measures were added to the regressions, they explained additional variance beyond that explained by the component scores, but there was no consistent relation between simulated driving performance and any particular physiological measure

Design, assembly, and validation of a nose-only inhalation exposure system for studies of aerosolized viable influenza H5N1 virus in ferrets

<p>Abstract</p> <p>Background</p> <p>The routes by which humans acquire influenza H5N1 infections have not been fully elucidated. Based on the known biology of influenza viruses, four modes of transmission are most likely in humans: aerosol transmission, ingestion of undercooked contaminated infected poultry, transmission by large droplets and self-inoculation of the nasal mucosa by contaminated hands. In preparation of a study to resolve whether H5N1 viruses are transmissible by aerosol in an animal model that is a surrogate for humans, an inhalation exposure system for studies of aerosolized H5N1 viruses in ferrets was designed, assembled, and validated. Particular attention was paid towards system safety, efficacy of dissemination, the viability of aerosolized virus, and sampling methodology.</p> <p>Results</p> <p>An aerosol generation and delivery system, referred to as a Nose-Only Bioaerosol Exposure System (NBIES), was assembled and function tested. The NBIES passed all safety tests, met expected engineering parameters, required relatively small quantities of material to obtain the desired aerosol concentrations of influenza virus, and delivered doses with high-efficacy. Ferrets withstood a mock exposure trial without signs of stress.</p> <p>Conclusions</p> <p>The NBIES delivers doses of aerosolized influenza viruses with high efficacy, and uses less starting material than other similar designs. Influenza H5N1 and H3N2 viruses remain stable under the conditions used for aerosol generation and sample collection. The NBIES is qualified for studies of aerosolized H5N1 virus.</p