1941 research outputs found
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Powerful Outflows in Seyfert Galaxies : Wind- Vs. Jet-Driven Models
No full textAdvisor: Charles NelsonSeyfert galaxies are active galaxies characterized by luminous outflows from a central super massive black hole. The outflow mechanism has not been fully determined, but the two primary competing systems are a wind-driven conical outflow and a jet-driven cylindrical outflow. We are developing
models with a variety of parameters, including inclination, cone opening angle, etc. By varying these parameters, we can add detail to the model to more completely match the observed velocities. We compare the models to the Hubble Space Telescope long-slit spectra of the Seyfert galaxies NGC 1068 and NGC 4151 in an effort to more fully understand the actual outflow mechanism of these galaxies.Drake University, Department of Physics and Astronom
Ectoparasite Abundance and Individual Color Variation in Three Cardueline Finch Species
No full textAdvisor: Muir EatonElaborate and/or colorful bird plumages have often been hypothesized to evolve via sexual selection for increased ornamentation. Differences in coloration among individuals can be influenced by a number of variables, including diet, hormones, and disease resistance. Specifically, Hamilton and Zuk
22 (1892) hypothesized a link between an individual’s parasite resistance and more colorful plumage signals, as a mechanism for individuals to advertise their ‘quality’. While much data has accumulated documenting the nutritional and hormonal regulation of various types of plumage coloration, relatively
little data exists reporting the effects of parasite load on individual plumage colors (i.e. melanin and carotenoid pigmented feathers). We collected ectoparasites and plumage color data from 24 purple finches (Carpodacus purpureus), 11 pine siskins (Carduelis pinus), and 21 American goldfinches
(Carduelis tristis). We found substantial individual variation in both total parasite load and quantified measures of feather coloration, and we report on the association between these variables among individuals
within each species.Drake University, Department of Biolog
Design Of An All-Optical WDM Lightpath Concentrator
Get PDFA design of a nonblocking, all-optical lightpath concentrator using wavelength exchanging optical crossbars and WDM crossbar switches is presented. The proposed concentrator is highly scalable, cost-efficient, and can switch signals in both space and wavelength domains without requiring a separate wavelength conversion stage
Relationship Between Field Soccer Skills and Computer-Simulated Soccer Skills
No full textAdvisor: Davis S. SenchinaThe evolution of video games seems to have revolutionized the way many pursue entertainment, activities, and now, even fitness. With physically interactive games systems such as the Wii being taken by a storm it may lead one to question where the virtual aspect ends and actual physical skill begins.
What role, if any, does skill in the suggested physical subject have on the virtual world and visa versa? The purpose of this experiment was to explore this matter. This research was conducted collecting data from 15 subjects. We examined both field soccer tests (shooting, slalom completion, and sprint with dribble) and Wii FIFA performance as our model for comparison. Our research project was hypothesis-driven and we predicted to uncover a positive correlation between field soccer skills and Wii soccer skills because theoretically skill in one area should enhance performance in the other. First, we found no difference in Wii soccer video game performance when subjects were playing another human versus playing the Wii computer itself. We then focused on just the subject vs. Wii data set. Statistical analysis of 3 separate comparisons between Wii performance and field skill performance
uncovered no significant correlations. Further research can and should be explored to consider
alternative variables that may yield different results.Drake University, International Relations Program, Biochemistry, Cell, and Molecular Biology Program, Department of Biolog
Examination of the Relationship Between Dribbling Footstrikes and Shots-on-Goal Scored in Soccer Field Tests
No full textAdvisor: David S. SenchinaTeam sports require coaches to determine which skills are most beneficial to scoring opportunities and how to divide practice time for maximum benefit for players. This experiment was designed to determine if a relationship existed in skills between 2 physical tests: 100 m sprint with ball dribble
and shots-on-goal from 5 sites on the field. Foot contacts, time to completion, and heart rate at end of sprint were all measured. It was hypothesized that there would be a positive linear relationship between ball touches and goals scored. Subjects with soccer experience would use more touches to keep the ball close and in control, to prevent opponents from taking the ball. Pearson correlation was performed. No significant correlation was found between goals scored and ball touches, within all subjects or within soccer participants. A general positive correlation appeared, but in each case, these results were not significant. Participants with soccer experience on a turf field specifically could be used in further studies to have a better sample. Additionally, competitive players could be compared to amateur players to examine for a difference.Drake University, Department of Biology, Neuroscience Progra
Electrolyte (Na+, K+, Cl-) Concentrations in Assorted Sports Drinks and Milk
No full textAdvisor: David S. SenchinaSweat production during exercise results in a loss of electrolytes, particularly chloride, sodium and potassium ions as well as a loss of water. Sports drinks attempt to give athletes the proper ions needed to replenish the body, as well as increase the osmolality to improve fluid balance. Research in this field currently focuses on the effects of consumption of different rehydration solutions used both preand
post-exercise. However, the analysis and comparison of concentrations of ions in different sports rehydration drinks has not been performed by third parties. This experiment focused on comparing the concentrations of chloride, sodium and potassium ions of Gatorade, Powerade, HyVee, All Sport, Propel, Muscle Milk and milk; when possible, we compared fluid versus powdered forms also. Samples from each type of sports drink were diluted and analyzed using EasyLyte Plus(TM), an electrolyte analyzer, examining concentrations of chloride, sodium and potassium ions. Significant differences
were found between levels of sodium and potassium of (1) Gatorade Endurance and Gatorade, (2) Gatorade and Propel,(3) milk and all sports drinks, (4) Muscle Milk and all sports drinks. Differences in chloride levels were found in all of the above, except between Gatorade Endurance and Gatorade. No differences in electrolyte concentrations were found between liquid and powder versions of sports drinks. Concentrations of electrolytes differed in some rehydration drinks and could impact
ion concentration and resultant fluid balance in athletes and dehydrated individuals.Drake University, Department Biology, Neuroscience Progra
The Adults Talk Too Much : Interviews With Low-Income Urban Middle School Girls
No full text96 leavesThe focus of this study is to examine the social and academic experiences of low-income
girls in an urban middle school, and to understand, from the girls' perspectives, how to
improve urban education for their benefit. Study participants included seven girls who
were interviewed three times toward the end of their eighth grade year. In addition to
interviews, the girls also provided written artifacts that they believed described them as
people and students. After the researcher extracted and coded themes from what the girls
said about their experiences, member checking was completed. The results of the study
were written as seven separate case studies. Additionally, the themes that arose from the
study were explored and discussed. This study found that, while the girls generally
enjoyed middle school more than they expected to, they had suggestions for improving
the middle school experience. The most salient theme to arise from the study was that the
girls felt that teachers and educators talk too much and seldom listen. Recommendations
for educators include the following: provide school day time for students to discuss race
and gender issues; find ways to make school more personal for students; listen to what
girls have to say; and talk less
Direct Contact Membrane Distillation
Get PDFAdvisor: Michael Flynn, NASA Ames Research Center, Moffett FieldDirect Contact Membrane Distillation (DCMD) is a primary membrane treatment process of the Direct Osmotic Concentration System (DOC), designed to recycle spacecraft wastewater. The DOC combines three separate processes to generate potable water from source separated hygiene water, urine, and humidity condensate. The DOC can achieve a high water recovery rate, has relatively low power requirements and can accommodate wastewater generated by six crewmembers. This system is designed for long-term human space missions, such as Mars exploration, because it minimizes the
need to resupply fresh water for crewmember use. The DCMD reclaims water from a feed solution consisting of urine, urine flush, and humidity condensate by creating a 15ºC temperature difference between the concentrated urine loop (at 40ºC) and the product water loop (at 25ºC). This induces a vapor pressure differential across the hydrophobic membrane, allowing water vapor to cross the microporous
membrane, while rejecting urea and ammonia nitrogen, among other foulants. The water
produced during pretreatment by both the Forward/Reverse Osmosis subsystems (FO/RO) and the DCMD is combined and undergoes secondary treatment by the Aqueous Phase Catalytic Oxidizer (APCO). A Total Organic Carbon (TOC) Analyzer determined the quality of the water produced by the DOC system. The TOC of water produced by the APCO was less than 3mg/L, which fulfills NASA drinking water standards. Testing resulted in an average of 96% water recovery with 98% TOC rejection. The average water production rate was 1.2 L/hr.Drake University, Biochemistry, Cell and Molecular Biolog
The Effectiveness of Innovative Wildlife Harvest Tools : Field Assessments of Behavior and Hunter Harvest Success
No full textAdvisor: Muir EatonFor centuries hunters have been using waterfowl decoys in an attempt to attract more birds for harvest, yet what makes a decoy effective is relatively unstudied. More recently, new paint technology has introduced decoy colors that aim to look more like real feather colors due to the addition of UVreflecting properties. This stems from research showing that birds have the ability to see UV reflectance due to a fourth type of cone cell sensitive from 300-410 nm (humans are blind to UV wavelengths, having only three cone cells, none sensitive to UV), and that duck feathers of many colors reflect UV light. Hence, our study aimed to investigate duck responses to decoys painted with UV
reflecting paint, with the prediction that these decoys will attract more waterfowl compared to decoys painted with traditional colored paints. During fall 2008 and 2009, we collected both behavioral data, recording the number of ducks and number of flocks to come within 50 m of the two types of decoys and the total time ducks spent within 50m of the decoys, and hunter success data, recording the number of ducks harvested using each type of decoy. We found more ducks and more flocks visited, and more total time was spent among, the UV-painted decoys, indicating an overall preference for these decoys compared to the traditionally painted decoys. However, success by hunters was similar using both types of decoys, suggesting that other factors involved with hunting may be more important than decoy appearance.Drake University, Department of Biolog
Malaria in Developing Countries : The Elusive Silent Killer
No full textAdvisor: John N. GituaMalaria is the most prevalent disease in Asia, Africa, Central and South America. Malaria is a serious, sometimes fatal disease caused by a parasite that is spread to humans through the bite of infected mosquitoes. The disease is a major health problem in tropical and sub tropical countries and the CDC estimates 300 -500 million new cases of malaria each year which results in the death of more than 1
million people. The most vulnerable to malaria infection include children less than five years of age, pregnant women and individuals with little resistance to malaria. Our study in this area is centered on the challenges involved in the prevention and cure of this disease as well as the opportunities now available in combating the spread of the malaria disease.Drake University, Department of Chemistr