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The Allelopathic Effects of Juniperus Virginiana on Native Iowa Plants
No full textAdvisor: Tom RosburgSome plants are known to produce allelopathic compounds that affect the growth of surrounding
plants and organisms. This study explores the effect of potential allelopathic chemicals produced by Juniperus virginiana on representative monocot and dicot species. Leachate was made by boiling cedar
foliage to represent rainwater leachate. A full strength and half strength solution was made and applied to corn and pea plants for about a month, with water used as a control. After a month of treatment, germination data and above ground biomass data were collected. Data collected from corn indicated a statistically significant difference between the control and full treatments for both germination and biomass growth (p = 0.016, P = 0.0032). Data from pea plants indicated no significant difference between the means for either germination or biomass growth data (p = 0.896, p = 0.968). The differences in responses are explored, and further research is suggested. The effect of allelopathy and the
degree to which certain individuals are affected is important for conservation.Drake University, College of Arts and Sciences, Department of Biology, Environmental Science and Policy Progra
Interactions of Miltefosine and Phospholipid DPPC at the Air/Water Interface
Get PDFAdvisor: Maria BohorquezSeveral Langmuir monolayer studies have suggested that the drug Hexadecylphosphocholine
(miltefosine) has a mode of action which is directly related to the cell membrane. Because the exact mode of action still unknown, the current study was aimed at examining the interaction of miltefosine and phospholipids. Specifically, the interaction of the phospholipid 1,2-Dihexadecanoyl-sn-glycero-3-
phosphocholine (DPPC) and miltefosine was investigated. Pure surface pressure-area (pi) isotherms of each component were obtained and analyzed through compression modulus (Cs-
1). Solutions analyzed were DPPC and miltefosine mixed monolayer solutions of 0.25, 0.40, 0.50, 0.60, 0.75, 0.82, and 0.90
XDPPC. The films were spread at room temperature on an ultra pure water subphase. Surface pressure area (pi) isotherms of the various mixed monolayer solution concentrations were recorded and characterized. Interactions of the molecules were analyzed through mean molecular area (A12) plots, and quantified through calculated excess free energy of mixing (Aexc) values. The results indicated DPPC and miltefosine mixed monolayers showed slight miscible behavior was seen due to the small deviations from ideality at low concentrations of DPPC. At higher concentrations and pressures, the DPPC and miltefosine monolayers showed positive deviations. This can be interpreted as being caused by a change in orientation of the polar groups during the compression of the monolayer and a result of the double bond in the hydrocarbon tail of the DPPC molecule.Drake University, College of Arts and Sciences, Department of Chemistr
The Effects of Acute Cocaine and Cocaine Withdrawal on Rats' Short-Term Memory Performance During Delayed Match to Sample Tasks in Y-Maze and Two-Lever Operant Paradigm
No full textAdvisor: W. D. KlipecWhile an extensive literature exists on the effects of cocaine on many different behaviors, there has been little research on the effects of cocaine withdrawal in rats. Recently we have been developing delayed match to sample tasks (DMTS) in a Y-Maze paradigm and two-lever operant task pursuant to examining the effects of cocaine withdrawal on short term memory (STM). The absence of an observing response made the Y-maze task difficult to learn for many of the rats, and performance was highly variable. Nonetheless, rats that were able to master the task, showed a marginally significant decrease in STM performance during a week following 7 days of exposure to 45 mg/kg of cocaine per day over three hours compared to saline control conditions. Using a two lever DMTS task, we found consistently faster learning and less variability in performance with memory delays ranging from 3 to 8-sec. Using four pilot rats, we found a weak, transient decrease in DMTS performance compared to saline control conditions, during a week where 45 mg/kg of cocaine was administered after each daily
training session, and after complete withdrawal from cocaine. Subsequently, we found that acute cocaine injections at 15 and 10 but not 5 mg/kg, prior to training sessions, disrupted DMTS performance. Although the two-lever DMTS task generates more accurate and less variable performance, it is
more difficult to disrupt STM. Accordingly, we are modifying the training conditions to make STM more difficult, and therefore more sensitive to disruption.Drake University, College of Arts and Sciences, Department of Psycholog
Granular Activated Carbon Versus Carbon Molecular Sieve as an Adsorbent inthe Lightweight Contingency Water Recovery System
No full textAdvisor: Charisse BuisingSeveral different carbon-based materials are contenders for use as an absorbent in the first stage of the Lightweight Contingency Water Recovery System (LWC-WRS). Granular activated carbon has been proven as an effective adsorbent, and is commonly used in water filtration. However, studies have
shown that carbon molecular sieve membranes outperform the activated carbon in adsorption capacity and efficiency. The adsorption capability of the carbon molecular sieve was examined to determine its ability to remove contaminants, primarily urea and ammonia, from wastewater through the LWCWRS. In addition, the endurance of both the activated carbon and the molecular sieve was tested to determine the volume of fluid that can be filtered through each matrix before adsorbent saturation. Preliminary data from column and batch tests run over a period between 4 to 12 hours showed the Total Organic Carbon (TOC) removal capability of the molecular sieve to be twenty times that of the activated carbon, with over 99% removal. After 11 hours and 1 L of urine processed, the molecular sieve continued to remove over 97% of the TOC in the initial urine volume. However, in line with its
performance, the molecular sieve is ten times more expensive per kilogram, than the activated carbon. This must be taken into account in the creation of L WC-WRS, especially if it is to be further developed
into a possible primary water treatment system for future spaceflight.Drake University ; University of Puerto Rico ; National Space Grant Foundation ; NASA Ames Research Cente
The Utilization Initial Testing of the Closed Loop Enthalpy Recovery DRYER System in Biological Environmental Systems for Microgravity Environments
No full textAdvisor: Charisse Buising, Kanapathipillai Wignarajah ; Sonny Kim of the NASA Ames Research CenterScientists and biologists at the National Aeronautics and Space Administration have dedicated thousands of man hours over the last 30 years searching for one important substance on distant heavenly bodies: water. It has often been theorized that a necessary component for almost certain existence of
life elsewhere in the universe is the existence of liquid water on that body. The recent possible discovery of frozen water on Mars illustrates both the necessity and excitement of this substance considered
common on Earth. The additional discovery of a possible ice geyser on Enceladus, one of Saturn's 18 moons, has prompted the possibility of other hospitable locations further out in the universe (1). Extended human missions into deeper space, as well as the beginnings of the lunar outpost, have
a few necessary factors for sustaining astronauts. The basic needs that we take for granted on Earth are devoid in space. The ability to safely and effectively recover water, oxygen, carbon sources and many other substances are important to moving from simply visiting space to becoming sustainable
fixtures. The ability to recover the water used by crew members is closely linked to the possible length of future missions (2). Creating a contained biome on a distant body means that every important substance must be recycled and reused. When looking at water recovery on lunar, Mars and microgravity
missions, there are a few different factors that must be considered. The safety of the crew, the duration of the mission, the energy draw of the machines, the autonomy of the machine in conjunction with other steps, the variety of moving parts and the amount of space taken up in the cabin by the apparatus. Research done by Dr. Michael Flynn at the NASA Ames Research Center have shown that being able to recover 100% of the water that would otherwise be lost or jettisoned out of
the cabin would save approximately $2.9 billion by ridding the need for additional water (4). There are many important substances from which the water must be recovered on an extended mission. These include food wastes, human metabolic wastes, inedible biomass and trash, salt brines and, eventually, crew clothing and composts. All these necessities must be addressed to establish the 10-year base on the moon (3). In addition, these hazardous substances must be contained in a space efficient manner until their resources must be utilized. A simple, new method, a closed loop dryer system was tested at Ames Research Laboratories. Called the "DRYER" and produced through an SBIR/STTR grant with the help of Orbitec Technologies and Cornell University, this method was compared to other ways of drying out and containing various substances.Drake University, College of Arts and Sciences, Department of Biology, Biochemistry, Cell and Molecular Biology Program ; Enterprise Advisory Services, Inc. ; NASA Ames Research Cente
Peripheral Blood Mononuclear Cell Cytokine and Proliferative Response to In Vitro Echinacea Stimulaton in Male College Wrestlers andSoccer Players During Preseason Practice
Get PDFAdvisor: David S. SenchinaThe effects of dietary botanical supplements on the immune response in athletes are unknown, despite a recent increase in herbal supplement use by both college and professional athletes. We conducted 2 separate studies to examine the effects of in vitro Echinacea stimulation on the immune responses of peripheral blood mononuclear cells (PBMCs) taken from athletes during preseason training. College-level male competitive athletes from 2 sports (wrestling and soccer) participated in the studies. PBMCs were isolated from blood sampled either pre- or post-practice, standardized to the same concentration, and then stimulated with extracts from Echinacea pallida, Echinacea simulata, or solvent
vehicle control. Cytokine production (TNF, IL-Ib, IL-I0, and IFN-g) was measured from super-natants collected between 24-72 hrs contingent on the specific cytokine; proliferation was assessed at 72 hrs. Extracts were phytochemically profiled by high pressure liquid chromatography to quantify known bioactive compounds including alkamides and caffeic acid derivatives. Results differed between the wrestlers and soccer players. In general, E. simulata was a more potent immunomodulator than E. pallida in both studies. Following exercise, PBMC production of TNF, IL-l0, and IFN-g production either decreased or was unaffected. IL-lb levels showed no change in either study. PBMC
proliferation increased in the wrestlers as a result of training, but decreased in the soccer players. In conclusion, observed effects were contingent on species chosen, time point within preseason training, and sport (training type).Drake University, College of Pharmacy and Health Sciences, Department of Biolog
The Effect of Aversive Early Experience on the Behavioral and Biological Fear Response in Rats
No full textAdvisor: Brian J. SandersThe effects of both positive and negative early life experiences on subsequent emotional reactivity are a major focus in current research on the etiology of neuropsychiatric disorders. Specifically, traumatic events, particularly when combined with genetic vulnerability, may exert a profound influence on the future psychological and biological development of an organism. In this study our lab examined the effects of a traumatic event early in life, maternal separation, on the future biobehavioral reactivity in animals with (borderline hypertensive rats) and without (Sprague-Dawley) a genetic predisposition for cardiovascular and emotional reactivity. Subjects were separated from the litter for two hours from post-natal days 1 through 14. Beginning at 6 weeks of age, anxiety-like behavior and locomotor
activity was tested by elevated plus maze and open field, respectively. One day following implantation of an arterial catheter, fear conditioning was used to produce an aversive emotional event (lO pairings an environmental cue (tone) followed by a brief lmA footshock). 24 hours later, emotional (e.g., freezing, vocalizations) and biological (e.g., blood pressure, corticosterone) responses were assessed in all subjects in response to re-exposure to the context (original context) and cue (altered context + tone). Results could provide an explanation for some of the differences between those susceptible
to neuropsychiatric disorders like PTSD and those who are resistant. Results may also be used to expand upon the emerging body of research concerning the link between cardiovascular disease and PTSD.Drake University, College of Arts and Sciences, Department of Psychology and the Neuroscience Progra
Effect of Stride Length Alterations on Heart Rate and Ratings of Perceived Exertion During Treadmill Running
No full textAdvisor: David S. SenchinaThis study describes results of exercise physiology research intended to examine the effects of running at normal, less than normal, and greater than normal stride length on heart rate (HR) and rating of perceived exertion (RPE). The objective of this study was to determine how running above or below
the natural stride length influences HR and RPE, and we hypothesized that any aberrations to normal stride patterns would result in increases in both HR and RPE. Three males and three females of moderate fitness were asked to run on a treadmill for three 10-minute periods, each separated by 10 minutes of recovery. The first trial allowed volunteers to select their own stride, while the remaining
runs were conducted with a metronome set at either 15% above or 15% below their normal gait. A significant increase was found in HR at both above- or below-normal stride length. RPE was increased during the below-normal stride length trial compared to other trials. We concluded that altering the normal stride length results in increased cardiac exertion and further studies into the negative
physiological consequences of this are warranted.Drake University, College of Arts and Sciences, Department of Biolog
"Punishment for my Sins," "Diet Pepsi," or "Bad Gene:" Perceived Causes of Autoimmune Diseases
No full textAdvisor: Nicole TaylorAutoimmune diseases are the fourth most common type of chronic illness yet the medical causes of the diseases remain largely unknown. Individuals who are diagnosed with autoimmune diseases often face many psychosocial consequences as a result of their disease including feelings of isolation, stress
coping with the cycles of relapse and remission, lengthy and ambiguous diagnosis processes, anxiety, and depression. The current study was part of a larger mixed-methods study that included online surveys
assessing disease severity, depression, self-efficacy, social support, positive well-being, and health promoting behaviors. Participants also completed open-ended questions asking, "What do you think caused your autoimmune disease?" and "Have you been given a medical explanation for the
cause of your disease?" Participants included 175 individuals with connective tissue or musculoskeletal autoimmune diseases and ranged in age from 18-84 years old. The most common diagnoses were rheumatoid arthritis, multiple sclerosis, systematic lupus erythematosus, and myositis. A content analysis of the open-ended questions revealed that many participants were unsure why they were diagnosed with an autoimmune disease. Participants who had received a medical reason for their diagnosis often expressed a personal belief that was different from what they were told by their
doctors. In addition, some participants blamed themselves for the etiology of their disease, even when that belief was contradictory to the medical information they had received. Lifestyle choices like drinking diet pepsi or working too hard were cited as reasons. The most common explanations were genes, environmental causes, bacterial or viral causes, medications like statins, stress, and pregnancy.Drake University, College of Arts and Sciences, Department of Psycholog
Comparison of Body Composition as Determined by Bioelectrical Impedance Analysis Using Lower-Body vs. Whole-Body Sampling
No full textAdvisor: David S. SenchinaBody fat percent measurement is an important indicator of health in the general public and important in athletics. The purpose of this study was to determine possible differences between a more expensive hand-to-foot (whole-body) bioelectrical impedance analysis (BIA) device (Bodystat1500?) and an inexpensive foot-to-foot (lower-body) BIA device (Tanita Innerscan BC534?). We hypothesized that there would be no difference in percent body fat or percent body water determination between the whole-body and lower-body method. Sixteen subjects of both genders volunteered to participate. Height and weight was taken on a physicians scale without shoes, then each subject had BIA performed
on them with both devices. It was found that there were no statistically significant differences between percent body fat and percent body water between the two machines. There was also no difference between the physicians scale and the Tanita for weight. Differences in recommended daily caloric intake (DCI) were statistically significant between the BodyStat and the Tanita with the Tanita recommending greater calorie consumption. This experiment showed that there was no difference between whole-body and lower-body BIA assessment using these specific devices. The cheaper foot-to-foot scale provides accurate measurements and is more practical for most people and regular athletes
to use.Drake University, College of Arts and Sciences, Department of Biolog