CFAES Undergraduate Research Forum

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The CFAES Undergraduate Research Forum provides a means for undergradute students to share their research with members and friends of the OSU community; recognizes the significant contributions to research by OSU undergraduates; facilitates exchange between students, faculty, and the public. The CFAES Undergraduate Research Forum started in 2004.

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Now showing 1 - 7 of 7
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    Managing corn in narrow row spacing - does intensive management make sense?
    (2017-02-28) Ritchie, Ashley; Lindsey, Alex
    Corn (Zea mays) in the United States is one of the most common plants planted by producers. The objective of this research was to compare how 15 inch and 30 inch row spacing in corn impacts foliar disease development, ear leaf nitrogen (N) content, response to foliar fungicide and N application, and grain yield. The rationale for the research was to inform farmers about the advantages and disadvantages of altering corn row spacing. A field trial was conducted at two Ohio locations (OARDC Northwest and Western Research Stations in Hoytville and South Charleston respectively). Two corn hybrids were grown in 15 and 30 inch rows, and were sprayed at corn silking (R1) with a foliar fungicide, foliar N, a combination of fungicide + N treatment and were compared to an untreated control. Measurements included foliar disease rating and ear leaf N content before and 14 days after application, and grain yield at maturity. The only disease that was seen on the corn ear leaf was gray leaf spot in the 15 inch and the 30 inch row spacing. Low disease levels at each location (< 11% leaf area covered by lesions) did not affect grain yield. The corn plants had little response to the four foliar treatments. Other findings were that row spacing had very little difference on ear leaf nitrogen uptake. The results from summer 2016 suggest intensive management (foliar fungicides and N application) may not provide yield benefit regardless of row spacing. This study will be conducted for another two years to validate the observed results. This research will help producers make management decisions to address questions related to increasing production on current agricultural land to support the growing global population.
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    Green Flourescent Protein Expression in Bone Marrow-Derived Mesenchymal Stem Cells of Immunocompetent and Athymic Nude Rats
    (2006-06-05T12:21:51Z) Ielapi, Joseph
    Concerns exist regarding potential differences in transgene product expression following gene delivery in immunocompetent versus immunocompromized animal models. To address this question in vitro, this study evaluated expression of green flourescent protein (GFP) in bone marrow-derived mesenchymal stem cells (BMDMSC) from immuncompetent and athymic nude rats following GFP gene delivery using a first-generation adenoviral vector. Cell types used were from 2-4-week old Wistar (Wstr) rats and 10-week-old NIH-rnu nude rats (Nude) of both sexes, and a BMDMSC from Lewis rats (Tul). Intensity and duration of GFP expression were documented every 48 hours in live cells using an in vivo imaging system with a cooled charge-coupled device camera. Intensity was measured in flux (photons/cm2/second/steradian). Expression was compared between cell types in cells in monolayer and three-dimensional alginate culture conditions. Flux values from days 0, 7, 12, and 22 were used for statistical comparisons. There was no significant difference in GFP expression between groups (immunocompetent versus immunocompromized). Rat breed and immune status had no effect on GFP expression (P >0.8, monolayer; P>.60, alginate). Flux values, expressed as a ratio of median expression in AdGFP-transduced cells to background levels, were as follows: Monolayer Day 0 -7792/1; Day 7 – 2634/1; Day 12 – 2592/1; Day 22 – 3819/1; Alginate Day 0 – 2304/1; Day 7- 529/1; Day 12 – 488/1; Day 22 421/1. Background flux was 2.50x106 for cells in monolayer culture and 1.42x106 for cells in alginate constructs. The AdGFP-transduced cells had 1800-fold greater expression, when compared with background values, in monolayer culture, and 525-fold greater expression in alginate constructs. Cells cultured in monolayer showed significantly greater expression compared to those in alginate constructs (P<0.05). These findings will provide valuable information for selection of optimal target cells for gene delivery using Ad vectors, and may alleviate concerns regarding potential differences in transgene expression between and immunocompromized and immunocompetent animal models.
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    PGF2a Inhibits VEGF Expression in the Corpus Luteum in the Mid but not Early Luteal Phase of the sheep Estrous Cycle
    (2006-04-25) Moritz, Stacey
    Vascular Endothelial Growth Factor (VEGF) is important for blood vessel development in a variety of tissues including an ovarian structure, the corpus luteum (CL). The CL is a transient endocrine gland that secretes progesterone, which prepares the uterus for pregnancy. In the absence of pregnancy, the corpus luteum regresses in response to endogenous prostaglandin (PG) F2α. Deficiencies in luteal function during early pregnancy may result in embryonic loss. Understanding of the mechanisms of luteal function could aid in the development of new methods to regulate fertility. Corpora lutea are susceptible to the luteolytic effects of PGF2αafter day 4 of the luteal phase; prior to that time the CL does not regress in response to treatment with PGF2α. The mechanisms responsible for the acquisition of responsiveness to PGF2α and the specific intracellular mediators of PGF2α induced luteolysis are unclear. The objectives of this research were to investigate if exogenous PGF2α affects VEGF mRNA expression in sheep corpora lutea and to determine if the effect is dependent upon whether the corpus luteum has not (early CL) or has (late CL) acquired luteolytic capacity. Mature female sheep (n=18) were randomly separated into two groups (early luteal phase, day 3, and mid luteal phase, day 10). Each group was divided into two treatment groups, PGF2αtreated and saline-treated (control). From each animal, one CL was removed at 2h and a second CL was removed 24h after treatment. Total RNA was isolated from each CL, purified, and verified for integrity. Real-time PCR was used for relative quantification of VEGF mRNA. The real-time methods were optimized and validated using two endogenous reference genes; β-actin and L-19. The quantity of mRNA present in each sample was standardized using the reference genes. The quantity of VEGF mRNA present in each sample was expressed as fold change from the mean value for the control CL collected on day 3 at 2h. Luteal progesterone concentrations were determined using radioimmunoassay. Data were analyzed using analysis of variance for a split plot design with sheep as the main plot and CL as the sub-plot. Quantities of VEGF mRNA were similar among CL collected during the early versus mid-luteal phase in the control animals (p>0.05). PGF2α had no effect on VEGF mRNA levels in early luteal phase CL collected at 2h or 24h after injection. In contrast, on day 10 of the estrous cycle, PGF2α treatment resulted in a marked (i.e., 10 fold, p<0.002) reduction of VEGF expression within 24h after injection; it is unclear if VEGF expression was changed during the first 2h after PGF2α administration at this stage of the cycle. There was no effect of PGF2α on luteal concentrations of progesterone during the early luteal phase (p>0.05). This is consistent with the expected lack of response at this stage. In contrast, PGF2α caused a decrease (p<0.03) in luteal progesterone in mid-luteal phase CL, demonstrating that these corpora lutea have acquired luteolytic capacity. Since the mid-cycle CL has acquired luteolytic capacity, it will regress in response to PGF2α. As such, the decline in the message for VEGF was associated with luteal regression. We conclude that inhibition of VEGF and subsequent vascular destabilization may be an important component of the luteolytic cascade invoked by PGF2α.
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    Use of Landfill Leachate to Generate Electricity in Microbial Fuel Cells
    (2006-05-26T20:03:04Z) Frew, Bethany
    Microbial fuel cells, in which microorganisms catalyze the transfer of electrons released from the oxidation of organic compounds onto an electrode, are a promising biotechnological approach for harvesting energy in the form of electricity from certain wastes. The purpose of this study was to determine if landfill leachate is a productive source of substrate and microbes for generating electricity in microbial fuel cells. Research methods included filling the anodic chambers of multiple fuel cells with landfill leachate. The cathodic chambers were filled with a buffer solution of KH2PO4 and were separated from the anodic chambers by a proton exchange membrane (NafionTM). Graphite plates were used as the electrodes in both chambers. Findings from this study show that microorganisms in landfill leachate are electrochemically active, and thus, landfill leachate can be an effective source of bio-electricity. Further results indicate that these electricity-producing microbes reside on the graphite anode, as opposed to being suspended throughout the leachate fluid. Experiments indicated that the leachate may lack enough carbon constituents (or food sources) to support long-term electrical generation. The addition of 10 mL of a 0.4% soluble sugar mixture (0.1% each of glucose, cellobiose, maltose, and xylose) provided enough food source for the microorganisms in the leachate to generate electrical voltage that was nearly three times the amount produced without the sugar mixture (0.120 volts). Furthermore, this maximum voltage generation (0.450 volts) continued for nearly two weeks, over twice the length of generation for the leachate without sugar. Additionally, leachate Chemical Oxygen Demand (COD) levels were reduced in initial tests after fuel cell electrical generation was complete, indicating that microbial fuel cells are potentially effective in treating landfill leachate. A cost analysis of a conceptual large scale design indicated that MFC technology is not mature enough to justify the implementation of this design based on economics alone. However, as energy costs continue to rise and MFC power production is maximized, MFC implementation could become more feasible.
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    Effects of dietary supplementation of unsaturated fat, vitamin E, and sorbitol on the performance of dairy cows and the fatty acid concentrations in milk.
    (2006-05-26T19:54:30Z) Todd, Amanda M.
    Dietary supplementation of soybean oil will increase conjugated linoleic acid (CLA) in milk but not to the extent that results from supplementing diets with fish oil. Data are limited on CLA in milk from feeding a combination of soybean and fish oils to provide different sources of fatty acids. There is some evidence that increasing dietary concentration of vitamin E may affect milk CLA when feeding unsaturated fat. Even though sorbitol is being used in commercial feed, limited published data are available as to its effects on animal performance and milk composition. Eight lactating dairy cows (4 Holstein and 4 Jersey) were used in a Latin square design. Each period consisted of 3 wk, with wk 3 being used for data analysis. Rumen samples were taken from the Holstein cows (one with rumen cannula and via stomach tube for the other 3 cows). Diets consisted of 44% forage (80% corn silage and 20% alfalfa hay), were mixed once daily as a total mixed ration (TMR), and fed twice daily. The cows were fed 4 diets: 1) control diet (CNTL; 500 IU vitamin E), 2) 2% fish oil, 0.5% soybean oil, and 500 IU of vitamin E (FSO), 3) 2% fish oil, 0.5% soybean oil, and 2000 IU of vitamin E (FSOE), and 4) 1% sorbitol (SORB, dry form; 500 IU vitamin E). Diets with oil reduced dry matter intake (DMI) (18.8 versus 22.7 kg/d), but DMI was similar between CNTL and SORB. Milk yield (31.7 kg/d) and milk urea nitrogen (MUN) (17.0 mg/dl) were similar among diets. Diets with oil reduced milk fat and protein percentages (3.87, 2.50, 2.58, and 3.96%; and 3.38, 3.09, 3.16, and 3.32% for CNTL, FSO, FSOE, and SORB, respectively). Body weight and rumen volatile fatty acids (VFA) were similar among diets. Concentrations of vaccenic acid (3.49, 8.03, 11.8, and 1.96% of fatty acids, respectively) and CLA (0.63, 1.28, 2.00, and 0.39%, respectively) in milk were increased with the diets containing oil; concentrations of vaccenic acid tended to be higher and CLA was higher for FSOE versus FSO. Both breeds responded similarly to the dietary treatments with respect to performance and most individual milk fatty acids. Addition of soybean and fish oils increased CLA in milk, but the higher concentration of vitamin E in combination with the oils further increased milk CLA. Feeding the sorbitol resulted in similar responses as to feeding the CNTL diet.
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    Supplemental rumen-protected choline and methionine for lactating dairy cows
    (2006-04-25) Engel, Joanna; Eastridge, Maurice; Ribeiro, Claudio
    The purpose of the experiment was to determine the effects of supplemental rumen-protected choline [Reashure® (REA)] and rumen protected methionine (Smartamine MTM). Analyses were performed to measure both milk and plasma choline, nonesterified fatty acids (NEFA) and plasma glucose and milk samples were sent out to be analyzed for milk fat, milk protein and milk urea nitrogen (MUN). 56 lactating dairy cows were fed one of 4 diets at parturition: 1) Control (duodenal flow of lysine:methionine (lys:met) 3.8, NRC 2001), 2) 0.26% rumen protected choline (RPC) (REA fed at 60 g/d to provide 15 g/d of choline; lys:met 3.8; REA-L), 3) 0.52% RPC (REA fed at 120 g/d to provide 30 g/d of choline; lys:met 3.8; REA-H), or 4) 0.096% rumen protected methionine (Smartamine MTM, Adisseo, Antony Cedex, France; lys:met 3.0; MET). The diets were fed as a TMR for 13 weeks and were composed of 52% forage (76% corn silage and 24% alfalfa hay), 9% whole linted cottonseed and 39% concentrates. The diets were 16.8% crude protein, 39.2% NDF and 20% forage NDF. 31 Holstein and 17 Jersey (48 total) completed the trial. Upon analysis, DMI (20.6 kg/d), milk yield (36.5 kg/d), milk fat (4.35%) and milk protein (3.14%) were found to be the same between all 4 diets. MUN was the highest for REA-H (19.1 mg/dl) and intermediate for MET (18.1 mg/dl). Milk choline showed a significant increase for MET, but plasma choline and NEFA were not different for the diets. Plasma glucose was higher for both the control and MET diets than for either REA diet. Plasma methionine was significantly higher for the MET diet than for other diets. Milk choline was a better indicator for choline status than was plasma choline and cows on the MET diet showed a higher milk choline concentration than did those on the RPC diet.
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    Adapting USEPA protocol for the detection and enumeration of Giardia and Cryptosporidium in an agricultural setting
    (2006-05-23T17:46:13Z) May, Cynthia L.
    An ecological water treatment system that utilizes a series of plants and water tanks is being tested at the Ohio State University Waterman Dairy as an alternate method for agriculture waste management. Giardia and Cryptosporidium are two genuera of parasites that can be found in most surface water supplies due to runoff from agricultural facilities, sewage treatment plants, or wildlife areas such as forests. As a result, the level of these two parasites in the water supply is a concern in regards to public health. The purpose of this study, initially, was to evaluate viability of the United States Environmental Protection Agency (USEPA) Method 1623 commonly used for detection of Giardia and Cryptosporidium in surface water with an untraditional sample source—agricultural waste. An additional purpose was to evaluate the level of Giardia and Cryptosporidium cysts and oocysts entering the ecological treatment system and the level exiting the system, thus determining the efficiency of the system for reduction of parasitic load. Method limitations were established by enumerating stock organisms, running spiked distilled water controls, and finally using experimental samples from the agricultural waste entering the water treatment facility. The USEPA Method 1623 was used to evaluate the level of Giardia and Cryptosporidium in the samples. Eluted samples were concentrated, stained, and observed via immufluorescence. Modifications to the published protocol were made to account for the difference of this project’s sample type (agricultural waste verses surface water) and to account for not using immunomagnetic separation (IMS) for the concentration of the sample. The major finding from this project is the inability of a capsule filtration unit recommended in the the USEPA Method 1623 to evaluate the parasitic load in agricultural waste samples. The particle size and load, despite sieving of the sample, overtaxes the filter used in the sample processing system. This makes elution and recovery of the cysts and oocysts near impossible. An accidental finding occurred in regards to cysts and oocyst integrity and the ability to detect their presence efficiently with immunofluorescent staining. Alternate methods will need to be investigated in order to properly detect and quantify Giardia cyst and Cryptosporidium oocyst levels for the ecological water treatment system processing agricultural waste as this capsule filtration testing system is ineffective because of particle size and load in the waste. In addition, further research into cyst and oocyst integrity verses the ability to detect with immunofluorescent staining will need to be pursued.