Sigma Xi Abstracts 2006

Sigma Xi
2006
Student Research
Poster Symposium
Abstracts
University of Mississippi
E.F. Yerby Center
04 April 2006
The University of Mississippi
Chapter 184 of Sigma Xi
Sponsored by:
The Office of Research & Sponsored Programs,
The Graduate School,
Sally McDonnell Barksdale Honors College,
School of Pharmacy, School of Applied Sciences,
School of Liberal Arts, School of Engineering,
National Institute for Undersea Science and
Technology, National Center for Natural Product
Research and American Association of University
Women
Student Poster Symposium
April 04, 2006
E.F. Yerby Center
Schedule of events:
1:30 – 3:30 PM
Poster Judging
6:00 PM
Poster Awards Ceremony
Brandt Memory House
406 University Ave.
i
Poster Summary Statistics
This year 61 posters were presented by OleMiss graduate (50) and undergraduate (11) students
representing 16 University departments. Thirty-six females and 25 males presented posters.
Thirty-seven advisors from 17 University departments encouraged their students to participate.
Fifteen awards will be presented this year: SigmaXi, 10; Sally McDonald Barksdale Honors
College, 1; American Association of University Women, 2; National Institute of Undersea
Science and Technology, 1 and National Center for Natural Products Research, 1.
Category
Biological Sciences
Chemical Sciences
Engineering Sciences
Environmental Sciences
Health Sciences
Math and Computer Sciences
Social Sciences
2002 2003 2004 2005 2006
4
6
7
9
5
8
15
16
10
18
15
11
6
22
15
5
5
8
7
6
8
9
6
15
7
6
9
6
5
4
7
7
7
6
46
62
56
75
ii
61
Total
Number Percent
31
10.33
67
22.33
69
23.00
31
10.33
45
15.00
30
10.00
27
9.00
300
100
Abstract Index
Category
Biological Sciences
Chemical Sciences I
Chemical Sciences II
Chemical Sciences III
Engineering Sciences I
Engineering Sciences II
Environmental Sciences
Health Sciences
Math & Computer Sciences
Social Sciences
Pages
1-3
4-7
8-10
11-14
15-19
20-23
24-27
58-31
32-33
34-37
iii
#
Abstracts
5
6
6
6
9
6
6
7
4
6
Author Index
Author (last, first)
Akay, Onur
Al-Zoubi, Asem
Ballas, Mary Anastasia
Budukh, Parag
Burt, S. Duane
Chaudhary, Amit
Crocker, Rachel
Ding, Yuanyuan
Elshahawi, Sherif
Emerson, Beth
Faulkner, Alison A.
Faulks, Emily R.
Fuchs, John W.
Goyal, Ravi
Grisham, Katy
Gupta, Kapil
Hickman, Cammi
Huang, Wei
Jaiswal, Adarsh K.
Jayne, Christy
Klymko, Victor
Kutrzeba, Lukasz
Lacey, Suzanne
Ledbetter, Amanda
Loo, Chye-Hwa
Mathew, Frank
McElwain, Lucas
Mididoddi, Praveen K.
Mikki, Said
Moak, Teri
Mohammed, Asad Kareem
Moodley, Deshi
Patny, Akshay
Sammeta, Rohit
Singh, Nidhi
Sivaprakasam, Prasanna
Speaker, Anton
Staten, Shea
Category
Poster #
Page #
Environmental Sciences
1
24
Engineering Sciences I
2
15
Biological Science
3
1
Chemical Sciences II
4
8
Chemical Sciences I
5
4
Health Sciences
6
28
Chemical Sciences I
7
Math and Computer Sciences
8
4
32
Chemical Sciences I
9
5
Environmental Sciences
10
24
Environmental Sciences
11
25
Engineering Sciences II
12
20
Environmental Sciences
13
25
Biological Science
14
1
Biological Science
15
2
Engineering Sciences II
16
20
Chemical Sciences I
17
5
Engineering Sciences II
18
20
Engineering Sciences I
19
15
Social Sciences
20
34
Engineering Sciences II
21
21
Health Sciences
22
28
Social Sciences
23
34
Health Sciences
24
29
Engineering Sciences I
25
16
Math and Computer Sciences
26
32
Chemical Sciences II
27
8
Chemical Sciences III
28
11
Engineering Sciences I
29
16
Chemical Sciences III
30
11
Math and Computer Sciences
31
32
Chemical Sciences II
32
9
Chemical Sciences III
33
12
Engineering Sciences I
34
17
Chemical Sciences III
35
12
Chemical Sciences III
36
13
Health Scineces
38
29
Social Sciences
39
35
iv
Author (last, first)
Sun, Yang
Telang, Nakul
Thomas, Anwen
Thumma, Sridhar
Tilak, Amey S.
Tucker, Christina
van Dyke, Jessica G.
Vedam, Shree Deepa
Wan, Shaolong
Wang, Lei
Wang, Lu
Wang, Xueqing
Warnick, Jason E.
Weng, Wei-Chung
Weston, James
Wu, Xuan Hui
Zaiser, Jarrad
Zhang, Xu
Zhang, Yizhe
Zhao, Huaying
Zhao, Jianping
Zheng, Guiping
Zhu, Shiqian
Category
Poster #
Page #
Engineering Sciences I
40
17
Health Sciences
41
30
Biological Science
42
2
Chemical Sciences III
43
13
Environmental Sciences
44
26
Social Sciences
45
35
Social Sciences
46
36
Biological Science
47
3
Engineering Sciences II
48
22
Chemical Sciences II
49
Health Science
50
9
30
Health Sciences
51
Social Sciences
52
31
37
Engineering Sciences I
53
17
Environmental Sciences
54
27
Engineering Sciences I
55
18
Engineering Sciences II
56
22
Chemical Sciences II
57
10
Math and Computer Sciences
58
33
Chemical Sciences II
59
10
Chemical Sciences I
60
Engineering Sciences I
61
6
18
Chemical Sciences I
62
6
iv
Biological Sciences
Biological Sciences
3) BELIZE SEAGRASS COMMUNITIES ARE DECLINING
Anastasia Ballas and Gary R. Gaston. Department of Biology, University of Mississippi,
University, MS.
Belize shallow-water lagoons support extensive beds of seagrass that are critical to the health and
survival of the coral reefs and seafood industry. Seagrass ecosystems are among the most highly
productive on earth, and their importance ecologically and economically is well established.
There is concern that seagrass beds are diminishing worldwide. Monitoring the seagrass
communities of Belize is possible using remotely sensed images and GIS, and these methods
eliminate the labor-intensive field-based techniques of the past. PURPOSE: This study
assessed the scale of spatial and temporal change in the dominant seagrass species Thalassia
testudinum (turtlegrass) in the South Water Caye Marine Reserve, Belize, Central America (16º
54’ to 16º 46’N; 88º 04’ to 88º 07’ W) over a 43-month period. METHODS AND RESULTS:
Two remotely sensed images were classified and analyzed according to the coverage of
Thalassia testudinum: an Ikonos image acquired on 12 September 2001 (1-m resolution) and a
QuickBird image acquired on 10 April 2005 (0.61-m resolution). Using Erdas Imagine 8.7 and
ENVI software, the two images were divided into a grid of 125m x 125m squares, and then a
random-number generation selected for the squares to be analyzed. Unsupervised classifications
using an ISODATA algorithm allowed for the coverage of seagrass to be classified and
compared for the two images. A change detection was then performed to determine the
percentage change in seagrass coverage over the 48 month period. The areas of change were
then compared to determine if the gains and/or losses varied throughout the region.
CONCLUSIONS: Seagrass beds in much of the South Water Caye Marine Reserve appear to be
diminishing; however, several areas show promise of new growth. These data indicate a trend of
moderate seagrass-habitat loss in Belize, which may indicate a downturn in habitat quality.
14) MATURATION OF CA2+ SIGNALING IN OVINE PULMONARY ARTERIAL
MYOCYTES
Ravi Goyal1, Kara Creel1, Erica Chavis1, Lawrence D Longo2, Sean M Wilson1.
1
Department of Pharmacology, University of Mississippi, University, MS, 38677; 2
Department of Physiology and Pharmacology, Loma Linda University, Center for
Perinatology, Loma Linda, CA, 92350.
Maturational adaptations in Ovine cerebral arterial smooth muscle function and Ca2+ regulation
of arterial tone have been clearly demonstrated. However, far less is known regarding the
maturational adaptations in Ca2+ homeostasis in arterial myocytes of the pulmonary vasculature,
even though this tissue undergoes dramatic changes in blood flow following parturition. Thus,
we tested the general hypothesis that with maturation there are changes in Ca2+ signaling in
isolated pulmonary arterial smooth muscle cells (PASMCs) studied by imaging cytosolic Ca2+
with fura 2. The results show that cells from fetal and adult have functional sarcoplasmic
reticulum (SR), in that cytosolic Ca2+ increases were induced by 10 µM cyclopiazonic acid, a
sarcoplasmic-endoplasmic Ca2+ ATPase inhibitor. Maturation, however, greatly affects Ca2+
release responses from the SR Ca2+ pool. PASMCs from fetal and adult had similar Ca2+
responses to 10 mM caffeine, a selective ryanodine receptor agonist; the percentage of
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responding PASMCs and the magnitude of the Ca2+ response were both similar. However, 100
µM ATP and 10 uM serotonin (5HT) elicited responses in fewer fetal cells. Notably, only a few
adult and fetal cells responded to 10-100 µM phenylephrine (PE). In responsive cells, Ca2+
elevations were significantly reduced in response to 100 µM ATP and 10-100 µM PE. However,
in fetus and adult 10 µM 5HT elicited small Ca2+ responses that were of similar magnitude. This
work supports the general hypothesis that Ca2+ signaling is changed with maturation. These
changes in responsiveness are diverse with heterogeneity in coupling based on developmental
age as well as the receptor-signaling system examined. NIH 2P01HD031226 (LDL),
R03AI55642, NIH 2P01HD031226 (LDL), R03AI55642 and UM FRP (SMW), UM GSC (RG).
15) SIGMA RECPTOR MODULATION OF INTRACELLULAR CALCIUM IN SMOOTH
MUSCLE
Katy Anna Grisham, Olga Ostrovskaya, Ravi Goyal, Rae Matsumoto, Sean Wilson,
Department of Pharmacology, The University of Mississippi, University, Mississippi
Cell signaling is an integral part of all body processes, including smooth muscle contraction.
The main mechanism of signal transduction is through activation of receptors many of which are
on the plasma membrane of cells. Sigma (σ) receptors are relatively unstudied receptors that are
distributed throughout the central and peripheral nervous system and in peripheral organ and
cellular systems. It is known that they may be useful in psychiatric disorders as well as cancer
biology, immunological responsiveness and cardiac and smooth muscle contractility. Sigma
receptors may act, at least in part, through the regulation of the intracellular calcium
concentration. We therefore tested the general hypothesis that sigma receptor stimulation
modulates cytosolic calcium in vascular smooth muscle, which are thought to express sigma
receptors. This increase leads to an increase in muscle contractility. This hypothesis was tested
by exposing vascular smooth muscle cells from mice and rat as well as canine to DTG, a sigma
ligand while monitoring the cytosolic calcium using a digital fluorescence imaging system. The
interaction between α-adrenergic stimulation and sigma-receptor stimulation was examined in
some experiments. The results show that there were differing responses depending on the types
of tissues and species examined. Mouse mesenteric arterial smooth muscle cells were fairly
unresponsive to DTG while those from rat exhibited a limited response and canine pulmonary
arterial smooth muscle cells responded modestly to the sigma agonist. These results provide
evidence that sigma receptors are expressed in vascular smooth muscle cells from some species
and that there is heterogeneity in the responses observed. While the present studies are far from
definitive they illustrate that sigma receptors may have potential therapeutic value, which
warrants further investigation.
42) PHENOTYPIC CHANGES IN ADULT RHESUS NEURAL STEM AND PROGENITOR
CELLS TOWARD AN OLIGODENDROCYTE PRECURSOR FATE
Anwen Thomas1, Dr. Bruce Bunnell2, Dr. Scott Davis2. 1Department of Anthropology,
University of Mississippi, University, MS; 2Tulane National Primate Research Center, LA
Adult stem cells are believed to be multipotent, that is having the ability to differentiate
into many different cells within the germ layer of origin. This study tested the hypothesis that
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neural stem and progenitor cells (NSPCS) from the adult rhesus monkey could be induced along
an oligodendrocyte precursor pathway.
Gene and protein expression profiles of naïve NSPCs were studied by RT-PCR,
immunocytochemistry, and Western blotting. The cells were then cultured in serum free media
containing bFGF and EGF resulting in neurosphere formation. These spheres were differentiated
for 10 days in serum free media containing NGF, BDNF, and NT-3 to which 1 µL retinoic acid
was added daily. Immunocytochemistry for the neuronal protein MAP2ab and the glial proteins
GFAP and O4 were performed on NSPCs prior to and after differentiation.
Results of these experiments suggest that adult rhesus NSPCs express “stemness” related
genes as well as several genes associated with neuronal and glial differentiation potential. The
neuronal marker MAP2ab was expressed in these cells at the gene and protein level. Following
neurosphere formation and differentiation, MAP2ab protein was absent from most cells and
translocated to a perinuclear location in other cells. In addition to a morphological change into an
oligodendrocyte precursor-like form, the oligodendrocyte/precursor marker O4, which was
absent in the naïve cells, was strongly expressed in the differentiated cells. GFAP, a marker of
type 2 astrocytes or O2A progenitor cells was co-expressed with O4.
Taken together, these results support the hypothesis that adult NSPCs can be coaxed
along different developmental lineages in vitro. By continuing to study the mechanism by which
adult stem and progenitor cells differentiate, we may discover the clues to manipulating
endogenous NSPCs in vivo to participate in the repair of demyelination resulting from many
debilitating diseases.
47) SIGMA RECEPTOR MODULATION OF RECEPTOR TRAFFICKING IN PC12 CELLS
Shree Deepa Vedam, M Loftin, RR Matsumoto, SM Wilson. Department of Pharmacology,
School of Pharmacy, University of Mississippi, University, MS
Sigma receptors are unique receptors with a wide distribution in CNS, PNS and non neuronal
tissues. Sigma receptors are found to have a role in cell proliferation, migration , cancer and in
the modulation of Kv and NMDA channels. Recent evidence suggests that sigma receptors
traffic from the Endoplasmic reticulum (ER) to plasma membrane (PM). Our studies are
designed to test the hypothesis that sigma receptor activation induces membrane trafficking.
Differentiated PC12 cells were used to study membrane trafficking as they express sigma-1
receptors. A fluorescent dye FM1-43, which selectively intercalates into membrane exposed to
the bathing solution, was used to measure total membrane turnover. DTG, a well characterized
sigma agonist and Ionomycin which induces calcium responses, and thus calcium-dependent
trafficking, were used to test the central hypothesis. We observed heterogeneous responses in the
cells treated with DTG and Ionomycin (N =109). 62 of the 109 cells examined responded to both
DTG and Ionomycin while 72 cells responded moderately to DTG and 96 to ionomycin. We
found there to be a poor correlation between the DTG and Ionomycin induced trafficking events.
This suggests that the pathways responsible for generalized calcium-induced membrane
trafficking and sigma-receptor mediated trafficking are independent. This work was supported by
NIH R01 DA011979-04, R01 DA013978 (RRM) and R03 AI55642 (SMW).
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5) A BIOASSAY-GUIDED INVESTIGATION OF THE CHEMISTRY AND
ANTIMALARIAL ACTIVITY OF A MARINE SOFT CORAL OF THE GENUS
ASTEROSPICULARIA
S. Duane Burt, S. Ankisetty, and M. Slattery. Department of Pharmacognosy, School of
Pharmacy, University of Mississippi, University, MS 38677
Asterospicularia is a genus of soft coral predominant in the Indo-Pacific. A crude extract of this
genus was tested for antimalarial activity, and revealed to have an 83% inhibition of the
protozoan Plasmodium falciparum (D6 clone) in primary screening. Secondary screening
produced a S.I. >11.0 and an IC50 at 4300 ng/ml for the D6 clone, and, a S.I. >14.0 and an IC50 at
4300 ng/ml for the W2 clone, indicating definite antimalarial activity. Throughout several
bioassay-guided fractionations, however, the antimalarial activity continually diminished. The
original goal of isolating the antimalarial active compound(s) subsided; nevertheless, the
bioassay-guided fractions had compounds present that perhaps once had antimalarial activity,
thus producing the new goal of identifying the chemistry present within these fractions.
This investigation afforded the two steroids gorgosterol and cholesterol. Additionally, a
triglyceride and a fatty acid ester were also isolated. Liquid chromatagraphic techniques such as
TLC, VLC, GLC, and HPLC were extensively used in separation and isolation. Furthermore,
multiple 1D and 2D NMR experiments, as well as GC-MS, were combined for structure
elucidation. Additional physical properties of the isolated compounds were also obtained in the
form of optical rotation, IR and UV data.
7) QUANTITATIVE ANALYSIS OF COMMON DRUG PRECURSORS BY FOURIER
TRANSFORM INFRARED SPECTROSCOPY
Rachel Crocker, Rilwan Oyetunji, Jennifer Greaux and Murrell Godfrey. Department of
Chemistry and Biochemistry, University of Mississippi, University, MS.
Fourier Transform Infrared Spectroscopy (FTIR) is widely used in the qualitative analyses of
both organic and inorganic samples. For example, many state and national crime laboratories
tend to use FTIR spectroscopy when identifying and characterizing substances retrieved at
different crime scenes. However, the majority of the crime laboratories rarely quantitate case
work due to lack of time and manpower. Therefore the main objective of this study is to quantify
different drugs based on previously generated spectra. This was achieved by improving upon the
previous technique of creating standard (calibration) curves for compounds of known
concentrations, making it easier to determine the percent of a drug in a sample. In the present
work, solid and liquid samples are prepared using the transmission technique of potassium
bromide (KBr) pellets. The samples are analyzed using least squares analysis and the data plotted
in a graph of amount versus area under the curve (AUC). The potassium bromide pellet results
yielded correlations between 0.84 and 0.93 for the five different active ingredients found in
nonprescription pain relievers. The resulting standard curves (calibration) from the solids are
compared to data obtained through liquid sample analysis and compared to samples of unknown
amounts. The unknowns are placed in an ultraviolet-visible spectrometer to confirm actual
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concentrations. The spectra obtained in this study will be used to establish a more diverse library
of known compounds. This data will in turn decrease the amount of time and money invested
into the forensic analysis of various compounds making identification and quantification in crime
laboratories achievable.
9) HPLC/PDA COMPARISON OF THE SOFT CORALS SINULARIA MAXIMA, S.
POLYDACTYLA AND THEIR HYBRID
S. Elshahawi 1, S. Ankisetty 1, M. Slattery 1,2. 1Department of Pharmacognosy, 2National
Center for Natural Products Research, The University of Mississippi, University, MS, 38677.
Soft corals are a group of colonial invertebrates belonging to the phylum Cnidaria. Sinularia
constitutes a major portion of the biomass in the tropical reef environment. Hybridization may
lead to the generation of qualitiative and quantitative differences in the secondary metabolite
production (Orians, 2000). Less attention has been paid to this phenomenon in the sea. Our lab
has discovered hybridization between the soft corals S. maxima X S. polydactyla. (hybrid was
confirmed using sclerite structures, molecular techniques and cross fertilization) (Slattery et al,
unpublished data). Chemical investigation of the hybrid has offered a novel compound;
polymaxenolide, in addition to four other new compounds (Kamel et al, 2004). We sought to
study the chemical differences and similarities between the hybrid and each of the two parents.
The organic extracts of the parents S. maxima and S. polydactyla and their hybrid were subjected
to silica gel chromatography. Marker compounds were isolated using various chromatographic
techniques (Open normal and reverse phase columns, vacuum liquid chromatography, prep TLC,
crystallization, size exclusion chromatography, and HPLC). Structure elucidation was performed
using different spectroscopic methods (1D and 2D NMR), GC, UV, IR, and specific rotation.
Extracts of S. maxima, S. polydactyla and their hybrid collected from different places and years
were all extracted by accelerated solvent extraction (ASE) method under the same conditions.
Method development using HPLC/PDA was performed and the various crude extracts were
examined for marker compounds. Up to our knowledge, this is the first study to investigate the
variation in the chemistry between the hybrid and its parents in the marine system.
17) THE ANALYSIS OF A TWO OR MORE COMPONENT MIXTURE OF
PHARMACEUTICAL DRUGS BY THE USE OF ULTRAVIOLET/VISIBLE
SPECTROSCOPY
Cammi Hickman and Murrell Godfrey. Department of Chemistry and Biochemistry,
University of Mississippi, University, MS, 38677
The purpose of this study is to identify two or more pharmaceutical drugs present in a solution
and to accurately determine the concentration of those existing drugs. The UV-vis
spectrophotometer is used to measure the absorbance of organic chromophores in the ultraviolet
or visible spectrum. Drug concentrations are determined using the Beer Lambert relationship:
A=εbc where A is total absorbance, ε is the molar absorptivity constant of the free drug in
solution (M-1cm-1), b is the path length in centimeters (cm), and c is the concentration in moles
per liter (M). Absorbance of ligands is dependent on factors such as concentration, temperature,
and pH.
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The analysis of a two-component mixture theory is also applied in this study. This theory states
that if one of the components in the mixture absorbs well at one wavelength and the other
component absorbs weakly at this same wavelength and the same is true for the second
component at a different wavelength, then the concentration of both components can be
determined by the following equation: A1 = k11c1 and A2 = k21c2. Solving for these equations
simultaneously yields: c1 = (k22A1 – k12A2)/(k11k22 – k12k21) and c2 = (k11A2 – k21A1)/(k11k22 –
k12k21), where c1 is the concentration of component 1 at wavelength X, c2 is the concentration of
component 2 at wavelength Y, A1 is the absorbance at wavelength X, A2 is the absorbance at
wavelength Y, k11 is the molar absorptivity(ε) of component 1 at wavelength X, k12 is the ε of
component 2 at wavelength X, k21 is the ε of component 1 at wavelength Y, and k22 is the ε of
component 2 at wavelength Y. The results of this experiment will be useful in the field of
forensic toxicology/chemistry to identify and quantitate crime scene samples that are not pure
but are mixtures of drugs.
60) PHYTOCHEMICAL INVESTIGATION OF DAMIANA – A CONVENTIONAL HERBAL
APHRODISIAC
Jianping Zhao1 and Ikhlas A. Khan1, 2. 1Department of Pharmacognosy; 2National Center for
Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of
Mississippi, University, MS 38677
Damiana (Turnera diffusa Willd.), a plant that grows in the Central American, as well as in parts
of South America, was used by the ancient Mayan in treatment of giddiness and falling (loss of
balance). Mexican Indians have used it as an aphrodisiac beverage with a long history. Although
many other healing properties of this plant were reported, the aphrodisiac effect has been most
commonly employed as its principle use. In 1874, the damiana product was marketed in the U.S.
and was collected into the National Formulary from 1888 to 1947. The history of use of damiana
is full of interesting stories, as well as controversy. Once it was said to be a marvelous plant, and
later it was said to be a hoax. In recent years, plenty of botanical products containing damiana
appear on the market. The authentication of the material source, safety and efficacy of these
botanical products become big issues. Surprisingly, in spite of the long history of use, a
literature survey indicated that the phytochemistry of damiana has not been studied extensively.
Until now, there have been no sufficient chemical and pharmacological studies to substantiate
the alleged aphrodisiac effect. We report here some terpenoids and flavanoids isolated from this
plant. Their structures were elucidated by using spectroscopic and spectrometric methods.
62) ULTRA PERFORMANCE LIQUID CHROMATOGRAPHY COUPLED TO
QUADRUPOLE MASS SPECTROMETRY AS A TOOL FOR INVESTIGATING THE
METABOLISM OF BENZO[A]PYRENE BY CYTOCHROMES P450
Shiqian Zhu1, Paulo Carvalho2, Lie Li3, Bonnie Avery3, Kristine Willett1. 1Department of
Pharmacology, 2Department of Medicinal Chemistry, 3Department of Pharmaceutics,
University of Mississippi, University, MS
Benzo[a] pyrene (BaP) is a ubiquitous environmental, tobacco and dietary carcinogen which has
been implicated in human cancer etiology. BaP requires activation by the microsomal
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Chemical Sciences I
cytochrome P450s to reactive metabolites that cause DNA damage. High- performance liquid
chromatography (HPLC) has been widely used for the study of BaP metabolism. Recently, ultraperformance liquid chromatography (UPLC) has been introduced with improved performance.
UPLC takes full advantage of the small stationary phase particles and the high mobile phase flow
rate for superior resolution and increased speed. The overall enhancement in the
chromatographic resolution and peak capacity leads to an improvement in the MS sensitivity. We
currently established a new UPLC-MS method to separate and analyze BaP and the following
BaP metabolites: BaP-1, 6-dione, BaP-3, 6-dione, BaP-6, 12-dione, BaP-9, 10-dihydrodiol, BaP7, 8-dihydrodiol, BaP-7, 8, 9, 10-tetrol, 9-hydroxyBaP, 3-hydroxyBaP and internal standard 6hydroxy chrysene. In the present work this method has been applied to both in vivo and in vitro
samples, which showed the improvement in sensitivity, chromatographic resolution and speed
compared to the conventional regular HPLC.
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4) CORRELATING FUNCTIONAL STABILITY OF ENZYMES WITH ENZYMEINHIBITOR INTERACTIONS STUDIED BY ISOTHERMAL TITRATION
CALORIMETRY
Parag P. Budukh1, John Williamson2, and Christy M. Wyandt1. 1 Department of
Pharmaceutics, 2 Department of Medicinal Chemistry, The University of Mississippi,
University, MS 38677.
Purpose: Isothermal Titration Calorimetry (ITC) has emerged as a powerful tool to determine
the thermodynamic parameters of protein ligand interactions. It has been widely used to study
the activity and functional stability of biomacromolecules such as proteins, DNA and enzymes.
ITC is a valuable tool in the design and development of enzyme inhibitors due to the ability to
provide direct measurement of binding constants and enthalpy of enzyme-inhibitor interactions.
This study is an effort to combine these two applications of ITC by demonstrating that ITC can
be used to correlate enzyme activity with enzyme-inhibitor interactions. Methods: Carbonic
anhydrase II (CA-II) from bovine erythrocytes was selected as a model enzyme and topiramate
was used as its inhibitor for ITC experiments. Traditional enzyme activity assays were performed
simultaneously with the ITC experiments. VP-ITC from MicroCal (Northampton, MA) was
used. A suitable ITC method was developed to measure binding parameters for the interaction
between fully active CA-II and topiramate. Then the enzyme in pH 8 buffer solution was
incubated at 60 0 C. Samples were drawn at various time points and subjected to ITC and activity
studies. Results: The stoichiometric parameter ‘N’ obtained by ITC varied from 0.9 to 0.0012.
The binding constant and enthalpy did not change significantly. The amount of heat (Q) was
calculated. A nearly linear correlation is established when the amount of heat measured by ITC is
plotted as a function of enzyme activity determined using the traditional assay. Conclusions:
Enzyme-inhibitor binding data obtained by ITC can be used to estimate the activity and
functional stability of enzymes.
27) EFFECTS OF DNA METHYLATION ON FORMATION OF SECONDARY
STRUCTURES WITHIN PLASMID DNA REGULATORY REGIONS
Lucas M. McElwain and Randy M. Wadkins; Department of Chemistry & Biochemistry,
University of Mississippi, University, MS.
The presence of DNA secondary structures in genomic DNA has been observed in both
prokaryotes and eukaryotes.
Specifically, the extrusion of ssDNA and formation of
cruciform/hairpin structures within palindromic sequences or areas of high purine content may
occur during transcription. Secondary structures associated with regulatory regions are of
particular interest as potential sites for the binding of small molecules, which could alter the
expression of genes. The effect of DNA methylation on extrusion of secondary structures has
not been examined. This study characterized the qualitative effect of methylation of plasmid
DNA on the formation of hairpin structures. The plasmid pBR322 was transformed into three
different strains of E. coli: wild type with functional deoxycytosine and deoxyadenine
methyltransferases (dcm+ and dam+), BL21 strain (dcm+, dam-), and ER 2925 with no
methyltransferase activity (dcm-, dam-). The resulting purified plasmids were then digested with
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Chemical Sciences II
Mung Bean nuclease (MBN), a ssDNA-specific nuclease that cleaves in the terminator of the
ampR cassette. Hind III nuclease was used to linearize the circular DNA, and the digest reaction
mixtures were analyzed by gel electrophoresis for fragments characteristic of cleavage by MBN.
Initial observations of methylation on cleavage patterns among the varying plasmids will be
reported.
32) POLARITY OF POLAR-SOLVATED ZEOLITE INTERIORS AS PROBED BY THE
FLUORESCENCE OF PYRENE AND 1-PRYENECARBOXALDEHYDE
D. Moodley and E.H Ellison. Deptartment of Chemistry and Biochemistry, University of
Mississippi, University, MS.
Fluorescence spectroscopy has been used to investigate microenvironmental polarity in the
intraparticle cavity domains of zeolites X, Y, and ultra stabilized Y (USY) interfaced with
bathing polar solvents. Pyrene (PY) and 1-pyrenecarboxaldehyde (1-PCA) were employed as
fluorescent probes. Both probes reported a more polar environment in polar-solvated NaX and
NaY as compared to the corresponding bulk solvent. Typical pyrene III/I values obtained in
NaX and NaY ranged from 0.49-0.75, while those in bulk solvents ranged from 0.77-1.06. The
results show USY to be nonpolar relative to the ionic zeolites. III/I values obtained for USY
were 0.88-1.30. The studies show that the ionic nature of NaX and NaY and the hydrophobic
nature of USY strongly influence the microenvironment of the probe despite the presence of
highly polar solvents. Longer chained alcohols result in a more rigid environment within USY
as compared to shorter chained alcohols and hydrocarbons hence excimer formation is
substantially lowered with the use of longer chained alcohols, like hexanol as compared to
shorter chained alcohols such as methanol and ethanol. The uptake of naphthalene and
anthracene from 50% v/v, H2O/methanol solutions into USY has been shown.
49) FRET STUDIES OF CRO VARIANTS-DNA INTERACTION
Lei Wang, Haifeng Jia and Michael C. Mossing. Department of Chemistry and
Biochemistry, University of Mississippi, University, MS 38677
The Cro repressor of bacteriophage lambda is a simple DNA binding protein. Cro recognizes
lambda operator sequences as a homodimer of 66-residues subunits (Jana, Hazbun et al. 1997). A
number of Cro variants have been engineered to study dimerization and protein stabilities. Here
we investigated the kinetics and equilibrium of Cro variants to DNA binding properties. By
placing fluorophore 5-iodoacetamido-fluorescein (IAF) on Cro variants which transferred energy
to the acceptor Rhodamine labeled OR3 when they were mixed, we can monitor complex
formation through Fluorescence Resonance Energy Transfer (FRET). Either by Equilibrium
competition experiments or regular titration experiments similar equilibrium dissociation
constant (Kd = 1±0.2nM) values of single proline mutant Cro were obtained. The data shows that
single proline mutant Cro has the same affinity as wild type Cro, but the association is much
faster than wild type Cro through kinetics study by stopped-flow. The dependence of the
equilibrium extent of binding on the salt concentration was investigated. Linear plots of logKeq
versus logKCl were obtained and the slopes are 4±1. The results show that the affinities of
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Single Chain Cro and single proline mutant Cro for OR3 change dramatically over the range of
salt concentration investigated.
57) MONITORING THE FORMATION OF HAIRPIN SECONDARY STRUCTURE USING
LIFETIME-RESOLVED FLUORESCENCE
Xu Zhang and Randy M. Wadkins. Chemistry and Biochemistry Department, University of
Mississippi, University, MS
DNA secondary structures such as hairpins and cruciforms in gene regulatory regions play an
important role in regulation of transcription. We have investigated DNA hairpins as a model
system for studying the formation of secondary structures within single-stranded DNA. The
fluorescence properties of PdC (pyrrolodeoxy-citidine) and its dependence on DNA structures
characterized by intensity changes due to different lifetimes in duplex VS single-strand DNA.
Our results indicate that PdC could be used to monitor DNA transitions from duplex to hairpins.
We also demonstrate that PdC can act as an energy transfer donors for probing the binding of
small molecules to DNA.
59) CALCIUM BINDING TO EPITHELIAL CADHERIN DOMAINS
Huaying Zhao and Susan Pedigo. Department of Chemistry and Biochemistry, University of
Mississippi, MS, 38677
Cadherins are a family of calcium binding cell-adhesion molecules. Epithelial-cadherin is a
transmembrane protein that has 5 independently folded β-barrel extracellular domains. It
mediates calcium-dependent cell-cell adhesion through the most N-terminal extracellular
domains. Calcium ions bind at the interface of the extracellular domains changing the relative
disposition of the domains. Our work focuses on the first two-extracellular domains of
epithelial-cadherin (MECAD12). The crystal structure of ECAD12 (Nagar et al (1996) Science
380: 360-4) showed 3 calciums binding at the interface between the domains and requiring
residues from both domains as well as the short linker peptide that joins them. We used
tryptophan-fluorescence and circular dichroism to monitor the local and global conformational
change as a function of calcium concentration. Titration curves were analyzed according to two
models (Equal/independent, and Unequal/cooperative). There was no wavelength-dependent
difference indicating that tryptophan signal at 235 nm monitors 2o structure. Resolved binding
constant is 30,000M-1 which is consistent with the result from fluorescence experiments
(20,000M-1). We report stoichiometric binding studies of MECAD12 at different protein concentration
by Isothermal Titration Calorimetry. We used both direct and indirect titrations to determine the binding
parameters. Indirect titrations utilize the addition of excess metal ion or chelator. The results have
important implications of the mechanism of calcium binding to cadherin molecules.
(Funded by NSF MCB 0212669)
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Chemical Sciences III
28) INFLUENCE OF HYDROXYPROPYL CELLULOSE MOLECULAR WEIGHT ON THE
DRUG RELEASE PROPERTIES OF POLYMERIC FILMS CONTAINING A MODEL
ANTIFUNGAL DRUG
P. Mididoddi1, T. Durig2, R. Grasso3, M. Repka4. 1Department of Pharmaceutics, 4The
National Center for Natural Products Research, The University of Mississippi, University,
MS, USA; 2Aqualon, A Business Unit of Hercules Inc., Wilmington, DE 19808; 3Analytical
Service Division, Hercules Inc., Wilmington, DE 19808.
Purpose. To determine the influence of hydroxypropyl cellulose (HPC) molecular weight (MW)
on the drug release properties of polymeric films produced by hot-melt extrusion (HME)
technology. Methods. HME technology was used to prepare thin polymer films containing
itraconazole and Klucel® HPC grades EF, LF, JF, GF or MF Pharm respectively (spanning the
MW range of 80 to 850 kDA). Random samples (n=4) were taken and analyzed for drug
concentration by a stability-indicating HPLC assay. Release studies were performed using a
Hanson SR8-Plus™ dissolution test system according to USP XXVIII apparatus 5, paddle over
disk method. Results. The theoretical post-extrusion content of itraconazole remaining in the
five film batches was excellent for these preliminary studies. For example, post-extrusion drug
content was 97.2% (±3.0) for the Klucel® HPC JF (MW:140 kDA) film. The release profiles
suggested that all five film formulations containing different MW HPC were able to control
itraconazole release. However, approximately 52% (±0.8) and 41% (±0.1) was released at the
end of 10h from the Klucel® HPC GF (MW:370 kDA) and Klucel® HPC MF (MW: 850 kDa)
films, respectively, whereas 80% (±2.0) release occurred from Klucel® EF and Klucel® LF (MW:
80-95 kDA) films at the same time interval. The dissolution rate decreased with an increase in
polymer molecular weight. Conclusion. HME is a viable technology to produce thin, stable, and
homogenous drug-incorporated HPC films. Data from this study indicate that matrices produced
via HME utilizing various Klucel® HPC grades can be used for the controlled-release of poorly
water-soluble drugs.
30) IN SILICO SELECTION OF INHIBITORS OF CARBOXYLESTERASES.
Teri Moak1, RM Wadkins1 and PM Potter2. 1Department of Chemistry and Biochemistry,
University of Mississippi, University, MS; 2Department of Molecular Pharmacology, St. Jude
Children’s Research Hospital, Memphis, TN.
Carboxylesterases (CE) are ubiquitous enzymes responsible for the metabolism of xenobiotics.
In humans, there exist two CE’s: one localized to the liver (hCE1) and the other to the small
intestine (hiCE). Both enzymes convert the anticancer pro-drug CPT-11 into its active form.
The hiCE is more effective in this activation. Harmful side-effects due to byproducts produced
from the hiCE activity in the human intestine make it an undesirable location for activation. A
series of selective inhibitors of hiCE have recently been identified, and QSAR models describing
their activity have been developed. In this poster, we utilize computational chemistry techniques
to generate in silico ligands developed via fusion of chemical fragment libraries. These new
virtual ligands were screened against the QSAR models to predict novel ligands for subsequent
synthesis. In particular, indole-containing ligands were predicted to be highly active and
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Chemical Sciences III
selective against hiCE. Consequently, these compounds are currently being synthesized for
experimental testing.
33) COMPARATIVE PROTEIN STRUCTURE MODELING OF THE HUMAN
ANGIOTENSIN II TYPE 1 (AT1) RECEPTOR: INSIGHTS INTO THE MOLECULAR
DETERMINANTS OF THE AT1-LIGAND INTERACTIONS
Akshay Patny1, Prashant V. Desai1, and Mitchell A. Avery1. 1Department of Medicinal
Chemistry, University of Mississippi, School of Pharmacy, University, MS, 38677.
Angiotensin II Type 1 receptor (AT1) belongs to the family of G-protein coupled receptors
(GPCRs). AT1 antagonists like losartan and telmisartan are effectively used in the treatment of
hypertension. A model of the human AT1 receptor with all connecting loops was constructed
from the 2.6 Å resolution crystal structure (PDB id: 1L9H) of the bovine rhodopsin. Initial model
generated by MODELLER was subjected to stepwise refinement by first docking one of the
representative non-peptide AT1 antagonist followed by several rounds of iterative molecular
dynamics simulations and energy minimizations. The model was validated based on its ability to
explain several site-directed mutagenesis results and known ligand-receptor interactions. For
further validation, additional non-peptide AT1 inhibitors were docked in the active site of the
model. Promising correlation between the docked score and the corresponding binding affinity of
the ligands clearly indicates that a reasonable model of the AT1 receptor has been derived which
can be utilized for future structure based drug design projects.
35) A COMBINED TARGET-BASED AND LIGAND-BASED APPROACH FOR THE
IDENTIFICATION OF NOVEL INHIBITORS: APPLICATION TO SALVINORIN A, A
SELECTIVE KAPPA OPIOID RECEPTOR (KOP) AGONIST
Nidhi Singh1, Gwénaël Chevé1, Sanju Narayanan1, Christopher R. McCurdy1,2. 1Department
of Medicinal Chemistry and Laboratory for Applied Drug Design and Synthesis, 2Research
Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi,
University, MS 38677.
A molecular modeling strategy using Salvinorin A derivatives recently reported in the literature
as kappa opioid receptor (KOP) agonist was designed. A 3D pharmacophore model was
developed using Catalyst software, which produced 10 pharmacophore hypotheses. The topranked hypothesis, characterized by a high correlation coefficient (r2 = 0.93), consisted of two
hydrogen bond acceptor and three hydrophobic features. This hypothesis was in agreement with
the site directed mutagenesis studies on KOP and correlated well with the actual and estimated
activity both in, training and test sets. Additionally, the hypothesis complements a threedimensional KOP model developed in our laboratory. This pharmacophore will be used in
conjunction with the comparative model to screen large chemical databases for the identification
of potential KOP agonists. It is anticipated that this hybrid computational screening approach
may be more effective for lead discovery as against making use of pharmacophore or
comparative model alone.
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36) PHYSICO-CHEMICAL AND STRUCTURAL REQUIREMENTS AMONG 3-ANILINO4-ARYLMALEIMIDES FOR GSK-3α INHIBITORY ACTIVITY ENHANCEMENT
THROUGH 2D AND 3D QUANTITATIVE STRUCTURE ACTIVITY RELATIONSHIPS
(QSARs)
Prasanna Sivaprakasam1, Pankaj R. Daga1, Aihua Xie1, Robert J. Doerksen1,2. 1Department
of Medicinal Chemistry, 2Research Institute of Pharmaceutical Sciences, University of
Mississippi, MS, 38677-1848, USA
Reported herein is our exploration of the binding forces and physico-chemical (hydrophobic,
electronic and steric) requirements among reported 3-anilino-4-arylmaleimides for glycogen
synthase kinase-3α (GSK-3α) inhibition. The lack of any reported 3D structure impedes
structure-based drug design for this novel target, which has been implicated in type-II diabetes
and in neurodegenerative conditions such as Alzheimer’s disease. 2D-QSAR investigations
based on the Fujita-Ban and Hansch methods on 3-anilino- and 3-N-methyl anilino-4arylmaleimides revealed electronic and steric interactions at the 4-phenyl ring and hydrophobic
interactions at the 3-anilino ring to be crucial for GSK-3α inhibition. Optimization of the 4phenyl ring of these compounds using Hansch-type QSAR analysis showed electron
withdrawing ortho-substituents as imperative for GSK-3α inhibition. The negative Esortho term
indicates that bulky ortho-substituents at the 4-phenyl ring enhance the activity. Hydrogen
bonding interactions between the acceptor groups like nitro or methoxy at 4-phenyl ring of these
congeners and the complementary donor groups of amino acids in the active site of GSK-3α
were identified. A combined analysis of 67 compounds with 3-anilino- and 3-N-methylanilinoderivatives showed that 3-N-methylation is not favorable for GSK-3α inhibition. Optimization of
the 3-anilino and 3-N-methylanilino rings showed hydrophobic meta substituents are crucial for
enhancement of GSK-3α inhibitory activity. 3D-QSAR studies using the CoMFA and CoMSIA
methods resulted in interesting insights to further probe the nature of interactions between these
compounds and the binding site of the α isoform. CoMSIA investigations suggest that hydrogen
acceptor features and hydrophobicity in addition to sterics and electrostatics are crucial for
determining binding towards GSK-3α for these compounds. Results discussed herein could be
used in designing more potent analogs to target the GSK-3α protein which in turn may prove to
be an efficient way to treat Alzheimer’s disease and diabetes.
43) FORMULATION OF A DELTA-9-TETRAHYDROCANNABINOL PRO-DRUG
UTILIZING POLY (ETHYLENE OXIDE) MATRICES
Sridhar Thumma1 and Michael A. Repka1,2. 1Department of Pharmaceutics, 2The National
Center for Natural Products Research, School of Pharmacy, The University of Mississippi,
University, MS, USA
PURPOSE: To study the effect of molecular weight of poly (ethylene oxide) (PEO) on the
bioadhesive properties, release characteristics, and stability of hot-melt casted films containing a
pro-drug of delta-9-Tetrahydrocannabinol (THC), THC-hemiglutarate (THC-HG). METHODS:
A hot-melt casting method was used to prepare PolyOx®PEO polymeric matrices incorporated
with 5% THC-HG. Bioadhesive measurements were performed on both placebo polymeric films
and those containing the drug (THC-HG) utilizing the TA.XT2i Texture analyzer equipped with
a TA-57R probe. The data was analyzed using Texture Expert™ software. Release studies were
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Chemical Sciences III
performed according to USP 28 apparatus-5, paddle-over-disk method. Film samples were
analyzed by HPLC. Stability studies were performed on the films at four different temperature
conditions (-18, 4, 25 and 40º C) to determine the % THC-HG remaining for up to 6 months.
RESULTS: Peak adhesive force and work of adhesion of each of the polymeric matrices was
found to increase with an increase in molecular weight of PolyOx®PEO. The presence of THCHG at a concentration of 5% did not significantly effect the peak adhesive force or work of
adhesion of the matrices. Sustained-release of the drug was observed from films containing
higher molecular weight PEO (80% drug released from PolyOx®PEO N-750 and PolyOx®PEO
WSR1105 in 9hrs and 12 hrs, respectively) while a faster release was observed from the lower
molecular weight PEO (100% drug release from PolyOx®PEO N-10 and PolyOx®PEO N-80 in 2
and 3 hrs, respectively). No significant degradation of THC-HG was observed in all of the
polymer matrices after one week. CONCLUSIONS: The results of the present study suggest
that lower molecular weight PEO can be optimized, both in terms of bioadhesion and release
characteristics, for the mucosal delivery of THC-HG.
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Engineering Sciences I
2) DESIGN OF LINEAR DIELECTRIC RESONATOR ANTENNA ARRAY FED BY
DIELECTRIC IMAGE LINE THROUGH NARROW SLOTS.
Asem Al-Zoubi, Ahmed Kishk, and Allen W. Glisson. Department of Electrical
Engineering, Ceneter for Applied Electromagnetic System Research, University of
Mississippi, University, MS.
Dielectric resonator antennas (DRAs) have been developed for use in the microwave and
millimeter frequency bands. Recently, the aperture coupled rectangular DRA fed by a microstrip
line was analyzed. For high-frequency applications microstrip feed lines have high conductive
losses, and surface modes could be excited which affect the gain of the antenna. Dielectric image
lines (DILs) are an alternate feed method that have lower losses at higher frequencies. The
aperture-coupled microstrip patch antenna fed by a DIL was analyzed and designed, and a good
gain, low return loss, and low back radiation were obtained. This work presents an aperture
coupled dielectric resonator antenna and arrays fed by dielectric image line. The modal
expansion method is used to describe the field on the DRA side and the change in the modal
voltage of the image line at the aperture is developed to analyze the single element DRA. The
DIL is assumed to propagate only the fundamental mode. The aperture is assumed to be narrow
compared to the wavelength of the DIL and the electric field in the aperture is assumed to be a
half-sinusoidal wave. The normalized input impedance can be determined from the power at the
aperture and the voltage difference across the slot. In exciting the DIL, the DIL is connected to
an X-band rectangular waveguide three-section transition in order to reduce the return loss.
HFSS commercial software is used to obtain the results for the transmission coefficient, return
loss, and radiation patterns.
19) DESIGN OF SMALL SIZE WIDEBAND QUADRATIC HYBRID.
Adarsh K. Jaiswal, Dr. Ahmed A. Kishk, Department of Electrical Engineering, The
University of Mississippi, University ,MS.
Compact and wideband quadratic hybrids are in great demand in communication systems as they
facilitate data transmission at microwave frequencies and are also preferred for their simple
designs and ease in fabrication. However, the conventional hybrid designs are narrowband and
occupy large size. Many attempts are being made to enhance the bandwidth of the quadratic
hybrids and also reduce their size. Here, the equivalent transmission line technique, which
converts a transmission line into a series transmission line and two open stubs, is employed to a
cascaded quadratic hybrid. The resulting stubs at the junctions of the two series lines are
combined and a narrow and short line is judiciously introduced at the junctions to further
enhance the bandwidth of the hybrid. The stubs are placed strategically to reduce the size of the
quadratic hybrid.
The designed hybrid is constructed on a RO3203 substrate having a dielectric constant of 3.05
and thickness of 1.54mm. Circuit analysis as well as the full wave simulations is performed for
the laid out design using Agilent ADS at a centre frequency of 2 GHz. Bandwidths greater than
50% were obtained from the simulation results which show a 46% size reduction when compared
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Engineering Sciences I
to the conventional cascaded quadratic hybrid. This design can be a judicious choice for
wideband applications with compact sizes. The designed hybrid is economical and can be easily
fabricated as it does not contain any air-bridged structures.
25) REAL-TIME DISTORTION INVARIANT OBJECT CLASSIFICATION WITH SDF
BASED FJTC
Chye-Hwa Loo and Atef Elsherbeni. Department of Electrical Engineering, University of
Mississippi, MS.
The task of object classification is complicated by variations in the three-dimensional (3D)
object, which translate into distortions in 2-D images. Distortions due to scale variations,
illumination, background clutter, occlusion, and in-plane and out of plane rotation hinder
successful recognition. The pattern matching for invariance classification requires a large amount
of data and computation time. PURPOSE: Proposed here is an efficient distortion invariant
object classification algorithm for real-time fringe-adjusted joint transform correlator (FJTC)
based automatic target recognition (ATR) system. METHOD: The proposed classification
technique employed fragment based ATR approach as well as a modified synthetic discriminant
function (SDF) in the generation of distortion invariant correlation filter sets. The optoelectronic
FJTC is then used to provide correlation of the filter sets and input under a proper arrangement.
This classification method is simple and fast and hence is relevant to be in use by real-time ATR
systems. A description of the optoelectronic system and the entire process is presented.
RESULTS: Simulation results are provided to prove the effectiveness of the proposed system in
the classification of objects invariant to scale as well as in-plane and out-of-plane rotations.
CONCLUSION: The proposed ATR method demonstrated invariant to aforementioned
distortions and is a very practical classification method for real-time object tracking applications.
29) PRACTICAL IMPLEMENTATION OF INFINITESIMAL DIPOLE MODELS AND
THEIR APPLICATIONS
Said Mikki and Ahmed Kishk. Department of Electrical Engineering, Center of Applied
Electromagnetic Systems Research, University of Mississippi, University, MS 38677-1848,
USA
Equivalent sets of ideal infinitesimal dipoles are used to represent a dielectric resonator antenna
(DRA). Since WIPL-D does not support sources of infinitesimal dipoles, a calibration procedure
is proposed to construct a realization of ideal dipoles within WIPL-D. Such a model facilitates
the study of the interaction of the DRA with other objects assuming that the presence of these
objects has negligible effect on the current distribution of the actual antenna. Therefore, the set
of dipoles can be used to study the interaction of the antenna under consideration with other
objects. The model is tested by comparing the fields radiated by the dipoles with the actual
fields of the DRA.
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34) UNDERSTANDING THE CROSSED FIELD TYPE OF ANTENNAS
Rohit Sammeta and Ahmed A. Kishk. Department of Electrical Engineering and Center of
Applied Electromagnetic System Research, University of Mississippi, University, MS.
One of the most recent developments in the field of antennas has been the introduction of the
Crossed Field Antenna (CFA). Invented in 1990 by Hately et al (Hately,M.C., Kabbary,F.M.,
Stewart,B.G., “Crossed-field-antennas”, IEE Colloquium on Electrically Small Antennas, 23 Oct
1990, Pages:5/1-5/5) the CFA gives extremely low inductive fields, small size at low
frequencies and very high field strengths. The authors claim that these unprecedented advantages
of the CFA are due to its unconventional working principle. Unlike other antennas, which radiate
electromagnetic waves due to a single time varying source, the CFA employs a method of direct
synthesis of the Poynting vector. Using different sources, the E and the H fields are synthesized
separately and after appropriate phase correction are made to ‘link’ to each other in an
‘Interaction Zone’. It is claimed that due to this artificial creation of the Poynting vector, which
uses no concepts of resonance, the size of the CFA is made frequency independent thus giving it
one of its biggest advantages over other antennas used at very low frequencies.
In this work we have tried to understand the working nature of the CFA and consolidate this with
simulations in the commercial software WIPL-D. We believe that the current explanation of the
working of the CFA rests on shaky mathematical background and a more intuitive and physical
explanation is warranted. Nevertheless the CFA works and the authors claim that along with the
presently functioning antennas in Egypt more are being built in other parts of the world.
40) A SOURCE MODEL OF VIDEO TRAFFIC BASED ON FULL-LENGTH VBR MPEG4
VIDEO TRACES
Yang Sun and John N. Daigle. Center for Wireless Communications, Department of
Electrical Engineering, The University of Mississippi, University, MS.
MPEG encoded video accounts for a considerable share of high-volume traffic in both wireline
and wireless networks of the next generation. MPEG video requires high bandwidth, and its
QoS is highly sensitive to packet loss, delay and bit error rate. Such unique features raise great
challenges for traffic engineering. However, the scarcity of video traces bottlenecks the
advances in video traffic study. In this paper, we propose a VBR video traffic model that
accurately characterizes VBR MPEG4 video traces and mimics their statistical properties. Two
highlights of our model include a novel scene-based Markov modulated process and the
feedback control on the frame size distribution. We validate our model by comparing various
statistics of the simulated traces with those of the original traces. It is shown that our model
provide an effective and efficient solution to obtain ample traces for video traffic analysis and
network performance evaluation.
53) IMPLEMEMNATION OF TAGUCHI METHOD FOR OPTIMAL DESIGN OF LINEAR
ANTENNA ARRAYS
Wei-Chung Weng, Fan Yang, and Atef Z. Elsherbeni. Department of Electrical Engineering,
The University of Mississippi, University, MS
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Engineering Sciences I
This study presents a novel implementation of an optimization technique to design linear antenna
arrays using Taguchi method. Taguchi method is developed based on orthogonal array (OA)
concept, which offers systematic and efficient characteristics. This study illustrates the
implementation procedures of Taguchi method in electromagnetic optimization problems.
Optimizations of linear antenna arrays have received great attention in the electromagnetic
community for many civilian and military applications. The proposed optimization procedure is
used to design three linear antenna arrays with specific array pattern requirements. Compared to
other optimization techniques, such as the genetic algorithm and particle swarm optimization,
Taguchi method is found to be easy to implement and is efficient in reaching the optimum
solutions. Numerical results show that a null controlled pattern, a sector beam pattern, and a
suppressed sidelobe level pattern are all successfully achieved using the versatility and
robustness of the proposed method.
55) ANTENNA MODELING BY FREQUENCY DEPENDENT HERTZIAN DIPOLES USING
PARTICLE SWARM OPTIMIZATION
Xuan Hui Wu, Ahmed A. Kishk, and Allen W. Glisson. Department of Electrical
Engineering, University of Mississippi, University, MS.
The Particle Swarm Optimization (PSO) method is used to obtain a set of frequency dependent
Hertzian dipoles to model the radiation characteristics of a wideband antenna. All the dipole
parameters are polynomials in the phase constant. The tangential electric field on a surface
enclosing the antenna is first obtained by full wave analysis or measurement at multiple
frequencies. The PSO method is then applied to determine the polynomial coefficients for each
dipole parameter, by minimizing the error between the exact or measured field and the field due
to the dipoles. The polynomial coefficients are not directly used to construct the optimization
parametric space because no knowledge of their ranges is available. Instead, several values of the
dipole parameters at different frequencies are chosen to construct the parametric space, and the
polynomial coefficients are computed afterwards by solving a linear system for each dipole
parameter. As an example, a wideband stacked DRA is modeled by four electric and three
magnetic Hertzian dipoles. The near-field data at 8 frequencies, from 7.5 to 11 GHz, are used to
compute the error of the dipole model. Four dipole models with different polynomial orders are
obtained and compared. The optimal one with second order polynomials is validated by WIPLD, by comparing both the near and far fields at different frequencies. Moreover, several cases
with the near-field data corrupted with Gaussian noise are investigated. It is found that the
Gaussian noise can be rejected by obtaining the Hertzian dipole model, and that the obtained
model is frequency scalable.
61) A NOVEL IMPLEMENTATION OF MODIFIED MAXWELL’S EQUATIONS IN THE
PERIODIC FDTD METHOD
Guiping Zheng, Ahmed A. Kishk, Alexander B. Yakovlev, and Allen W. Glisson.
Department of Electrical Engineering, Center for Applied Electromagnetic Systems
Research, The University of Mississippi, University, MS.
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To model periodic structures with oblique incident waves/scan angles in FDTD, the field
transformation method is successfully used to analyze their characteristics. In the field
transformation method, Maxwell’s equations are Floquet-transformed so that only a single period
of the infinite periodic structure can be modeled in FDTD by using periodic boundary conditions
(PBCs). A new discretization method based on the exponential time differencing (ETD)
algorithm is used to discretize the modified Maxwell’s equations in the periodic FDTD method.
This new discretization method provides an alternative way to discretize the modified Maxwell’s
equations with simpler updating forms that requires less CPU time and memory than the
traditional stability factor method (SFM). These two methods have the same numerical accuracy
and stability in the periodic FDTD method. Excellent agreement between the two methods is
obtained.
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Engineering Sciences II
12) USING BIOFORCE PROBE TECHNIQUE TO STUDY PRIMITIVE RED BLOOD CELL
MEMBRANE STABILITY.
Emily R. Faulks1 and R. Waugh2. 1Department of Chemical Engineering, University of
Mississippi, University, MS; 2Department of Biomedical Engineering, University of
Rochester, Rochester, NY.
Fetal mice exhibit two types of red blood cell lineages: primitive and definitive. Primitive mouse
red blood cells lacking erythroid Krüppel-like factor (EKLF) exhibit abnormal morphology and
disappear before achieving the biconcave shape of normal primitive blood cells. To explore
whether a mechanical instability in the cell surface contributes to this phenomenon, the cell
membrane stability of the EKLF -/- red blood cells was measured using a bioforce probe
technique and compared to the properties of primitive red blood cells from normal embryos. In
this technique, a long cylinder of membrane bilayer (tether) was formed between the primitive
cell surface and a bead. The process was observed in a light microscope, and the force required
to form the tether was measured. This force depends on the mechanical tension in the membrane
and the natural tendency of the membrane bilayer to remain attached to the cell surface. Our
preliminary data show that normal primitive blood cells and primitive EKLF -/- blood cells both
exhibit heterogeneous properties similar to those of maturing red blood cell populations of the
definitive lineage.
16) THERMAL MANAGEMENT OF A 4 X 4 TRANSMITTER/RECEIVER MODULE
ARRAY USING COPPER NANO PARTICLES AND ZIG-ZAG FIN CONFIGURATION
Kapil Gupta, Anil L. Jeswani and Jeffrey A. Roux. Department of Mechanical Engineering,
The University of Mississippi, MS, 38677.
Due to continuing reduction in size and increase in the functional performance of electronic
devices, heat removal has become a significant interest. Hence, in order to keep electronic
devices within the allowable temperature limits, proper heat dissipation, is very essential so that
the electronic devices can perform the intended task with maximum efficiency. This work
focuses in the same direction with a new approach; using copper nano particles in the cooling
fluid and zig-zag fins in the fluid channel to achieve maximum thermal management for the T/R
module array. The main objective of this analysis is to keep the maximum temperature of the
power amplifier chip below failure temperature. The simulations are performed for different
ambient conditions, flow rates and power settings. For simulation purpose Icepak (an electronics
cooling software package) has been used.
18) WIDEBAND DIELECTRIC RESONATOR SENSOR FOR MICROWAVE BREAST
CANCER DETECTION
Wei Huang and Ahmed A. Kishk. Department of Electrical Engineering, University of
Mississippi, University, MS 38677, USA
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Engineering Sciences II
According to the recent released statistics by the American Cancer Society, breast cancer is the
most leading cause of cancer death (other than lung cancer) of women, which means one in
seven American women has breast cancer during their lifetime. Early detection of breast cancer
is key element for reducing the mortality. Currently X-ray mammography is the most widely
used tool to diagnose and evaluate breast cancer. However, mammography and other ionizing Xray based methods are not safe for the patients since the ionizing radiation properties of the Xray may induce a new breast tumor. Also, mammography is not precise since it is very sensitive
to lesions (but not all lesions are cancerous). Moreover, it is too costly especially for low-income
women and women live in developing countries. As a new promising non-ionizing and
noninvasive radar-based breast detection method, microwave breast cancer detection based on
the contracts in dielectric properties between healthy (epsilonr=9 and sigma=0.4S/M) and
malignant (epsilonr=50 and sigma=4S/M) tissue, can achieve early detection and has the
advantages of low health risk, noninvasive and comfortable, and cost effectively and widely
available. One of the biggest challenges of microwave breast cancer detection is the sensor
design. The sensor should be compact, lightweight, suitable to be placed directly on the breast,
and with minimized ground plane. Additionally, it requires wide bandwidth for short pulse
radiation, and retains good matching when the sensors are in direct contact with the tissue. Here,
a wideband DRA sensor with small ground plane is designed for microwave breast cancer
detection. A coaxial probe excites a two-steps stair shaped DRA. To reduce the backward
leakage with the small ground plane size a quarter wavelength choke is added to the back of the
ground plane. The impedance bandwidth of 46% is achieved. The effect of attaching the sensor
to the breast tissue is investigated when the sensor is directly attached to the breast tissue.
21) DISPERSION CHARACTERISTICS OF THE PLATE WAVES IN PERIODICALLY
POLED LITHIUM NIOBATE.
Victor A. Klymko, AB Nadtochiy, and IV Ostrovskii. Department of Physics and
Astronomy, University of Mississippi, University, MS.
The dispersion dependencies k (ω ) of the acoustic waves in crystalline plates are under
study. We consider ultrasonic modes that propagate in two different substrates of lithium niobate
(LNO) including single crystal and periodically poled ferroelectric. The numerical calculations
and experimental measurements from ZX cut chip are done.
The surface electric potential and mechanical displacements along crystallographic axes
x, y, z are evaluated by the Finite Element method (FEM). We use further the discrete Fourier
transform to convert the acoustic displacements depending on frequency and coordinate into
theoretically calculated dispersion curves k (ω ) .
The electric potential is measured with the help of a metal probe sliding over the sample
surface. The double discrete Fourier transform of the experimental data are plotted in k (ω ) space
to observe the experimental dispersion dependency for a number of modes.
When the results from periodically poled crystal are compared to those from single
crystal, several new effects are observed. The set of periodically poled domains produce a
number of acoustic and vibrational resonances at certain frequencies that correspond to the
dimensions of the domains. These resonances appear as vertical lines on the k (ω ) plot. The
second effect is the reflection of all propagating modes from periodically poled domain structure.
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Engineering Sciences II
The set of the dispersion curves reproduce itself every k = 1 d mm-1 on k (ω ) plot, where d is the
period of the domain array. The third effect is a nonlinear interaction of two plate waves at a
frequency, where the waves have the same magnitudes of their wave vectors. At these
frequencies, two close dispersion curves that represent different modes are “pushed out” against
each other (“repulsion” of the modes). Fourth effect is nonlinear interaction of the direct and
reflected waves.
The results of this work can be used for design of new piezoelectric devices of next
generation that are based on periodically poled ferroelectrics.
48) REACTIONS OF COMMONLY USED TUBES AND SUPPORTING MATERIALS IN
THE STUDY OF SURFACE OXIDES ON CHARS AT HIGH TEMPERATURES
Shaolong Wan, Guang Shi and Wei-Yin Chen. Department of Chemical Engineering,
University of Mississippi, University, MS.
During temperature-programmed desorption (TPD) of oxidized chars and un-oxidized graphite in
highly purified He, we found unexpectedly large amounts of CO emission in the temperatures
range of 1100 and 1700°C. Thus, the role of alumina reactor tube at high temperatures became a
focal point in the search for the oxygen source for these CO emissions. In addition, the possible
reactions of silicon carbide tube and materials supporting the carbon sample, including ceramic
wool, beads, foam and rod have also been examined. All of them have been commonly adopted
in combustion research laboratories; their interferences have not been systematically reported.
It was discovered that the alumina tube with 99.7% Al2O3 is involved in two types of reactions at
high temperatures: oxygen release and adsorption of CO. Oxygen released from blank tubes
between 1100 and 1700°C seems to be due to the decomposition of Al2O3 to Al2O(g); the rate of
this reaction is greatly accelerated by the presence of reducing agents, such as carbon and CO.
The equilibrium calculations based on JANAF Thermochemical Tables reveal that equilibrium
O2 concentration from Al2O3 decomposition is only about 10-42 atm, but O2 release can be as
high as those observed experimentally when carbon is present. Adsorption of CO and its
subsequent reaction with the reactor tube result in formation of CO2 above 1200°C. SiC tube
does not suffer these shortcomings, but it is oxidized by O2 and CO2 during oxidation and forms
SiO(g) and CO above 650°C and 1200°C. SiC rod and foam do not emit CO in inert gas. SiC
powders release CO at high temperature, but repeated heat treatments eventually suppress the
CO emissions and render it possible for TPD. Alumina beads and wool release O2 and are not
suitable for study of reactions where the presence of a trace amount of oxidizing agent can be
detrimental to data integrity. Thus, SiC seems to be a good choice for TPD study but not suitable
for oxidative environments. Alumina is suitable for oxidizing environments where a small
amount of oxygen emission is tolerable.
56) EFFECTS OF MOISTURE, SALTWATER, AND TEMPERATURE ON AN AOC P920
POLYESTER E-GLASS PULTRUDED COMPOSITE
Jarrad Zaiser, James G. Vaughan and Ellen Lackey. Department of Mechanical Engineering,
University of Mississippi, University, MS.
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Engineering Sciences II
Composites are now being used in a variety of environmental conditions, and the effects of these
conditions are unknown. The objective of this study was to determine how AOC P920
polyester/E-glass pultruded composite, a unidirectional fiberglass reinforced composite, would
react to various environmental conditions. The conditions examined are elevated relative
humidity, increased temperature, saltwater submersion, and preloading. These conditions were
evaluated over several periods of time. The properties that were observed were weight and
flexural stress.
The results showed that in any environment of elevated moisture content, the test samples gained
weight. Figure 1 shows that samples submersed in saltwater gain more weight the longer they
are exposed. Some samples gained more weight than others according to the level of humidity
that they were exposed to. The peak stresses also show a decrease over an extended period of
time of exposure, seen in Figure 2. Figure 2 also shows that the higher the humidity levels the
more the peak stress decreases. A correlation can be drawn between the weight gain and the
peak stress decrease. The more weight the sample gains the weaker it becomes.
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Environmental Sciences
Environmental Sciences
1) INTERCONNECTIVITY OF MACROPORES AND SUBSURFACE DRAINS: IMPACT
ON BTCS
Onur Akay and Garey A. Fox. Civil Engineering, The University of Mississippi, MS, 38677.
Recent research indicates immediate breakthrough of solutes and pesticides in subsurface
drainage by extraordinarily efficient transport through directly connected macropores.
Macropores, such as those created by earthworm burrows, allows water and solute to transfer
directly to subsurface drains. Laboratory experiments are commonly utilized for investigating
this effect of macropore flow on contaminant transport. In this study, the interrelationship
between macropores and subsurface drains was investigated by conducting infiltration
experiments in a laboratory column packed with a sandy loam soil with an artificial macropore
directly connected. The goal of this study is to develop relationships relating soil, macropore and
subsurface drain properties to the probability of direct connection. A novel design of the
experimental setup allowed open surface and buried macropore lengths to be varied from the
subsurface drain to the surface without disturbing the soil column. Experiments were completed
for various macropore lengths ranging from zero (no macropore effect) to 75 cm (surface
connected macropore). Breakthrough curves were plotted for both matrix and macropore flow at
the outlet. The movement of the wave front of the infiltrated water down the column was
observed with pencil size tensiometers mounted on the side of the column at various depths.
With the surface connected macropore, breakthrough times decreased significantly compared to
buried macropores. It was observed that increases in buried macropore length (i.e., as the
macropore approached the soil surface) increased the percentage of total drain flow through the
macropore.
10) ANALYSIS OF MISSISSIPI AND ALABAMA WATER AND SEDIMENT SAMPLES
AFTER HURRICANE KATRINE WITH H4IIE AND YES ASSAYS
Beth Emerson1, Katherine Argote2, Amit Chaudhary2, James Weston2, Shabana Khan3
and Kristie L. Willett2. 1Chemistry and Biochemistry, 2Pharmacology and Environmental
Toxicology, 3National Center for Natural Products Research, University of Mississippi,
University, MS, USA
Hurricane Katrina struck the Mississippi and Alabama Gulf Coasts on August 29, 2005.
Following the extensive storm surges and flooding, this study was designed to test the
toxicological effects caused by the storm. On September 13, 2005, the first water and sediment
samples were collected with monthly collections following. Samples were collected from ten
sites along the Alabama and Mississippi coasts: Mobile, AL, and Biloxi, Grand Bay, Gulfport,
Ocean Springs, and Pascagoula, MS. Samples were extracted and filtered for analysis employing
the H4IIE rat hepatoma and the Yeast Estrogen Screen (YES) Assay. The H4IIE assay is used to
determine the induction of CYP1A by the presence of aromatic hydrocarbons. CYP1A activity
is measured by the deethylation of ethoxyresorufin into a fluorescent pink product, resorufin
(EROD). Maximal EROD activities for benzo(a)pyrene (BaP, 0.5 nM) and TCDD (0.5 nM)
were 6.1 ± 0.05 and 3.0 ± 0.11, respectively. Ultimately activity from Katrina extracts will be
expressed as percent of the highest concentration of BaP response measured in the EROD assays.
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Environmental Sciences
The YES assay is used for predicting the presence of potential endocrine disruptors based on
their binding and activation of the human estrogen receptor. The estrogen equivalents for the
water samples ranged from non-detectable to 5.5 ng/L at a Grand Bay, MS site (site #8). The
suspended sediment samples ranged from non-detectable to 1.4 ng/L at a Gulfport, MS site (site
#2). By the February sampling, estrogen equivalencies for all but the Back Biloxi Bay site were
below detection limits. Further analysis will be conducted with the H4IIE assay to measure
CYP1A induction of the water and sediment samples. Results from the YES assay will be
compared to NOAA’s pre-Katrina data, as available, with monthly collections and analytical
chemistry data to follow.
11) NITROGEN USE EFFICIENCY IN C3 AND C4 CYPERUS SPECIES AT THE
UNIVERSITY OF MISSISSIPPI FIELD STATION
Alison A. Faulkner¹, Marjorie M. Holland¹, M.T. Moore² and C.M. Cooper². ¹Department of
Biology, University of Mississippi, University, MS; ²USDA-ARS National Sedimentation
Laboratory, Oxford, MS.
The C4 pathway in Cyperus species is evidently an adaptation to temperate wetlands and sandy,
infertile environments. Cyperus species using the C4 pathway have high photosynthetic nitrogen
use efficiency (NUE), which appears to confer a high degree of success in wetlands with low
nitrogen concentrations. This translates to a possible competitive advantage over their C3
Cyperus counterparts where the latter conditions exist. Our six-month greenhouse experiment
was designed with two main purposes: (1) to follow up the work of Jason Beadle’s 2004 thesis
study on nitrogen and phosphorus uptake in two wetland plant species and to compare the two
studies’ results, and (2) to quantify and differentiate NUE in two co-occurring wetland species
found in ditches and wetland margins at the University of Mississippi Field Station: Cyperus
haspan, a C3 sedge, and Cyperus erythrorhizos, a C4 sedge. Each species is being subjected to
nitrogen dosing regimens at both 2.5 ppm and 4.0 ppm, representing typical lower and higher
nitrogen concentrations in agricultural runoff in Lafayette County. Mean NO3-N concentrations
analyzed from soil and interstitial water samples thus far are below analytical detection in all
treatments, while mean NH3-N concentrations range from 0.20–0.57 ppm in soil samples and
0.75-9.0 ppm in interstitial water samples. Results suggest that nitrates are being reduced into
ammonium form, which is expected in an anoxic environment. A combination of C3 and C4
sedges planted in treatment wetlands and agricultural ditches has the potential to partially treat
fluctuating levels of nonpoint source pollution better than using either of the two types singly,
since C3 sedges function to remove nitrogen at higher concentrations while C4 sedges tend to
remove nitrogen more efficiently at lower concentrations.
13) MEASURING STREAMBANK EROSION DUE TO GROUNDWATER SEEPAGE
John W. Fuchs1, Garey Fox1, Glenn Wilson2, Andrew Simon2, and Eddy Langendoen2.
1
Department of Civil Engineering, University of Mississippi, University, MS; 2USDA-ARS
National Sedimentation Laboratory, Oxford, MS
The National Water Quality Inventory continues to report sediment as the most or at least one of
the most severe pollutants of surface waters. Excessive sediment causes numerous water quality
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Environmental Sciences
problems. It increases the potential for downstream flooding, diminishes water quality and
destroys aquatic habitat. The two primary sources of sediment entering streams are erosion from
adjacent landscapes and erosion of streambank sediment. Research on upland erosion has led to
methodologies for controlling erosion from adjacent landscapes such as the use of best
management practices. However, excessive sediment continues to be a problem throughout the
United States. USDA-ARS scientists report that streambank material in many watersheds may
contribute as much as 80% of the total sediment, especially in some watersheds in Mississippi.
There exists a lack of information on one of the basic mechanisms governing sediment input to
streams from the streambank: erosion by groundwater flow or seepage erosion. The importance
of seepage erosion is not understood at this time, even though such an erosion mechanism has
been observed throughout the United States. The objective of this research was to characterize
streambank properties where seepage erosion contributes sediment to streams and causes bank
failure and quantify subsurface flows and seepage erosion of bank sediment that results in bank
failure at the two field sites. Subsurface flows and sediment loads were quantified using lateral
flow collection pans placed against exposed faces of the stream bank at pre-identified seepage
locations when seepage was occurring. Subsurface flow and sediment concentrations were
measured following rainfall events at both sites. These measurements were correlated to
precipitation data, soil pore-water pressure measurements, and stream stages to ascertain the
timing and importance of seepage erosion.
44) SYNTHESIS OF MANGANESE OXIDE COATINGS FOR ADSORPTION OF TRACE
METALS FROM GROUND WATER
Amey. S.Tilak1, Clint W. Williford2, Garey A. Fox1, and Terry Sobecki3. 1 Department of
Civil and Environmental Engineering, 2 Department of Chemical Engineering, The
University of Mississippi, MS, 38677. 3 Environmental Processes Branch, ERDC, U.S.
Army Corps of Engineers Vicksburg, MS, 39180-6199
Manganese oxide (MnOx) occurs naturally in soil and has high affinity for trace metals such as
lead, chromium, cadmium and zinc. Such heavy metals, when present in groundwater, will cause
health risks if they enter aquifer drinking water sources. Our aim is to produce and characterize
manganese oxide coatings on aquifer soil materials. The long term goal is to form a Permeable
Reactive Barrier (PRB) to adsorb trace metals. Syntheses of manganese oxide coatings were
carried out in the laboratory using continuous (column) reactor and batch reactor experiments on
clean Ottawa sand. In the column experiment, manganese and bleach solutions were cycled
alternately through a column of sand. The pH and ORP (Oxidation Reduction Potential) were
monitored during coating process. The pH ranged from (4-9).The ORP was (600-800) mV when
passing bleach and manganese solutions, and, (100-300) mV when passing DI-water. The
coating process was carried out for increasing numbers of the cycles 24, 48 and 72. Flow rate
was kept constant at 4ml\minute. After the coating process, a lead solution (50mg/L) was passed
at 4ml\min through the coated sand to determine the lead adsorption capacity on manganese
oxide coated sand. A lead selective electrode was used to plot breakthrough curves. The amount
of lead adsorbed for 24, 48 and 72 cycles was 500mg/kg, 760mg/kg and 2106mg/kg respectively.
An excavated aquifer soil will be investigated for coating synthesis and lead adsorption. The
batch studies performed on Ottawa sand used three oxidants: ozone, hydrogen peroxide and
bleach. For batch synthesis pH was investigated for a range of (6-9), and the initial amount of
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Environmental Sciences
manganese was varied from 0.3 to 3.0g Mn per100g sand. The manganese oxide formed on the
sand ranged from 63.6mg/kg to 10372.8 mg/Kg. The batch synthesis was repeated three times on
the same sand sample to examine the sequential buildup of manganese oxide coatings.
54) STORM EFFECTS ON ESTUARINE WATER QUALITY
James Weston. Department of Biology and Environmental Toxicology Research Program,
University of Mississippi, University, MS.
In 2005 the northern Gulf of Mexico experienced 1 tropical storm and 4 hurricanes, hurricane
Katrina being the most catastrophic, while the frequency and severity of tropical storms is
predicted to increase due to global warming. To better understand the impact of these pulse
disturbances on nearshore marine communities temporally and spatially explicit data are needed.
Within Grand Bay, MS, the National Oceanic and Atmospheric Administration (NOAA) and the
Mississippi Department of Environmental Quality (MSDEQ) established a National Estuarine
Research Reserve (NERR) to monitor water quality and other estuarine conditions. Four
automated dataloggers have been collecting water quality data in Grand Bay NERR since 2004.
Temperature, depth, specific conductivity, salinity, pH, dissolved oxygen, dissolved oxygen
percent saturation and turbidity are measured every 30 minutes. Because of Grand Bay NERR’s
temporal and spatial monitoring program a unique profile of storm related effects on abiotic
factors has been captured but not analyzed. Water quality conditions before, during and after
tropical storms and their change in magnitude and recovery to baseline conditions will be
qualitatively and quantitatively assessed and compared within and between Grand Bay NERR
sites. Data from last year, 2005, is currently being evaluated. Understanding the magnitude and
duration of abiotic stressors in estuarine systems is a step toward developing better monitoring
programs to assess ecosystem health and storm related disturbances.
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Health Sciences
Health Sciences
6) MECHANISTIC ANALYSIS OF CHEMOPREVENTATIVE FLAVONOIDS AND
BENZO(A)PYRENE IN PROSTATE CANCER CELLS BY 2D GEL
ELECTROPHORESIS.
Amit Chaudhary1, Tibor Pechan2 and Kristine Willett1. 1Department of Pharmacology,
University of Mississippi, University, MS, 38677, 2Life Sciences & Biotechnology Institute,
Mississippi State, University, MS, 39762
Prostate cancer is the most commonly diagnosed and second leading cause of cancer death in
men in the United States and many other western countries. Due to the long latency period of
prostate cancer and its prevalence in elderly men, it is ideal disease for chemoprevention. The
flavonoids apigenin, quercetin, and kaempferol are widely studied for their chemopreventative
potential in prostate cancer, but the specific mechanisms underlying and the proteins involved in
the cancer-protective effects of flavonoids are still not clear. One mechanism that we have
studied is the inhibition of CYP1A1 and CYP1B1 by these flavonoids. The three flavonoids
inhibited ethoxyresorufin-O-deethylase (EROD) activity, which is indicative of CYP1A1 and
CYP1B1 inhibition, in 22Rv1 prostate cancer cells and recombinant human CYP1A1 and
CYP1B1. BaP is a carcinogenic PAH and is a ubiquitous environmental contaminant. Exposure
to BaP is associated with prostate carcinogenesis, but the mechanism of BaP–mediated toxicity is
also still incomplete. 2D gel electrophoresis, a primary tool of proteomics where multiple
proteins are separated for parallel analysis, was used to resolve proteins from control (DMSO)
and flavonoid or BaP treated 22 Rv1 cells. Three independent extracts of each cell treatment
were prepared and run on separate gels. Images of stained gels were scanned and analyzed by
PDQuest software for the proteins which were differentially expressed (unique, upregulated and
downregulated). As compared to DMSO, 27 proteins in BaP, 48 proteins in quercetin, 14 proteins in
kaempferol and 10 proteins in apigenin were found to be differentially expressed. Proteins of interests were
robotically excised from the gels and trypsin digested, followed by MS/MS analysis using ABI 4700
Proteomics Analyzer (MALDI TOF/TOF).Mapping the difference in protein expression of BaP
or flavonoid treated 22Rv1 cells compared to controls, will facilitate better understanding of their
molecular mechanism in prostate cancer progression or chemoprevention, respectively.
22) MICROBIAL METABOLISM OF SALVINORIN A
Lukasz M. Kutrzeba1, Kelly Thomas1, John S. Williamson2, and Jordan K. Zjawiony1.
1
Department of Pharmacognosy, 2 Department of Medicinal Chemistry, School of Pharmacy,
University of Mississippi, University, MS 38677
Microbial transformation of natural products is a well known model of mammalian metabolism
and a source of analogs potentially useful in the drug development. Salvinorin A, a diterpenoid
isolated from hallucinogenic mint Salvia divinorum is the first known non-nitrogenous κ-opioid
receptor agonist. Both in vitro and in vivo salvinorin A undergoes fast hydrolysis of the acetate
function at the carbon atom C2, giving inactive salvinorin B. In our experiments, we used 30
fungi species as matrices for screening of biotransformation of salvinorin A. Our results have
shown that the chief process of salvinorin A biotransformation is also hydrolysis to salvinorin B.
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Health Sciences
24) ANTINOCICEPTIVE PROFILE OF SALVINORIN A, A STRUCTURALLY UNIQUE
KAPPA OPIOID RECEPTOR AGONIST.
Amanda J. Ledbetter3, Grant H. Smith1, Christopher R. McCurdy1,2,4, Kenneth J. Sufka2,3,4,
Jason E. Warnick3, & Marcelo J. Nieto1. 1Department of Medicinal Chemistry, 2Department
of Pharmacology, 3Department of Psychology, and 4Research Institute of Pharmaceutical
Sciences, University of Mississippi, University, MS, 38677 USA
Salvinorin A, is a structurally unique, non-nitrogenous, kappa opioid receptor (KOP) agonist.
Given the role of KOPs in analgesic processes, we set out to determine whether salvinorin A has
antinociceptive activity in thermal and chemo-nociceptive assays. The tail-flick assay was
employed to investigate 1) salvinorin A’s (0.5, 1.0, 2.0, and 4.0 mg/kg) dose–response and timecourse (10, 20, and 30 min) effects in a thermal nociceptive assay, and 2) the ability for the KOP
antagonist norBNI (10.0 mg/kg) to prevent salvinorin A antinociception. The hotplate assay was
utilized as a second thermal nociceptive measure to test salvinorin A’s dose–response effects.
The acetic acid abdominal constriction assay was used to study salvinorin A’s dose–response and
time-course (over 30 min) effects in a chemo-nociceptive assay. Together, these studies revealed
that salvinorin A produces a dose-dependent antinociception that peaked at 10 min post-injection
but rapidly returned to baseline. Additionally, pretreatment with the KOP antagonist
norbinaltorphimine (norBNI) reversed salvinorin A-induced antinociception. These findings
demonstrate that salvinorin A produces a KOP mediated antinociceptive effect with a short
duration of action.
38) EFFECTS OF REACTION TIME TESTING ON NEUROCHEMICAL MEASUREN IN
THE MATURE RAT AFTER HIGH-DOSE METHAMPHETAMINE INJECTIONS
Anton Speaker1, Karen Sabol1,2. 1Department of Psychology, 2Department of Pharmacology,
University of Mississippi, University, MS.
Donald Hebb introduced the theory of use-induced plasticity of the CNS in 1949. Since then
there have been investigations that found increased dendritic spine count in normally developing
animals following enrichment (Globus et. al., 1973). A natural biological response to insult has
been offered as one explanation for physiological recovery seen after brain trauma (Wagner et.
al., 2002; Kolb et al., 1991). Another explanation is that behavioral experience is an important
mediator of physiological plasticity after brain trauma (O’Dohohue et. al., 1983, Faverjon et. al.,
2002). In the present study we investigated the effect of environmental enrichment in the form of
an operant task on the adult rat after a neurotoxic regimen of methamphetamine. Thermal
transmitters were implanted into the abdominal cavities of rats. Once recovered, animals were
injected with either a high-dose methamphetamine regimen, 20 mg/kg 4 times at 2 hours
intervals (METH), or saline (VEH). Rat core body temperature was monitored in temperaturecontrolled chambers. Once recovered, rats remained in their home cages, standard condition
(SC), or were trained on a reaction time task, enriched condition (EC) for eight weeks. Animals
were then sacrificed, their brains removed and prepared for HPLC analysis. Results revealed that
the METH injections resulted in significant 5-HT depletions in the amygdala, ventral
somatosensory cortex and hippocampus. There was a borderline effect for enrichment found in
amygdala of METH EC rats, but not somatosensory cortex and hippocampus. These results
suggest some brain regions might benefit more from environmental enrichment following a
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Health Sciences
neurotoxic regimen of METH. Analysis of additional brain regions are underway; however, the
initial results reported here indicate that operant training in the adult organism may have
therapeutic benefits.
41) DESIGN, SYNTHESIS AND BIOLOGICAL EVALUATION OF ISOFLAVONES AS
ANTIGIARDIAL AGENTS
Nakul S. Telang1, Anuradha Illendula1, Babu Tekwani2, Shabana Khan2, and Mitchell
Avery1, 2. 1Department of Medicinal Chemistry and Laboratory for Applied Drug Design
and Synthesis (LADDS), School of Pharmacy: 2National Center for Natural Products
Research, University of Mississippi, University, MS
There is no doubt that pathogenic diseases have been the subject of research for medicinal
chemists since the turn of this century. One such pathogenic disease is giardiasis. It is caused by
unicellular protozoan, Giardia lamblia also known as G. intestinalis or G. duodenalis. It has
been identified as the major cause of most frequent waterborne outbreaks infecting 20–30% of
the population in developing countries and 2-5% in the United States. Also, the prevalence of
diarrhea caused by G. lamblia in AIDS patients is significantly higher than those without AIDS
due to suppressed immunity in these patients. Current mainstays of treatment for giardiasis are
Metronidazole and Furazolidone with reported cure rates of 80-95% and 80–89% respectively.
Recent reports on the development of parasite resistance and toxicity against conventional
antigiardial drugs have necessitated an urgent need for the development of novel, safe and
effective antigiardial agent.
Studies on naturally derived isoflavones such as formononetin and pseudobaptigenin have
unraveled their potential antigiardial activity in vitro. In order to conduct structure activity
relationship studies towards discovery of novel antigiardial agents, isoflavone libraries were
designed and synthesized using automated solid-phase parallel synthesis and were biologically
evaluated for antigiardial activity.
50) CYP1C1 mRNA EXPRESSION IN FUNDULUS FOLLOWING BENZO(A)PYRENE
EXPOSURE
Lu Wang1, Brian Scheffler2, Wu Dong1, Annette Ford1, Kristie Willett1. 1Pharmacology and
Environmental Toxicology, University of Mississippi, University, MS; 2 MSA Genomics
Laboratory, USDA-ARS-CGRU, Stoneville, MS.
While polycyclic aromatic hydrocarbon induction of CYP1A has been recognized for many years
in both mammals and fish, an understanding of the significance of the more recently cloned fish
CYP1B and CYP1C genes is lacking. In mammals, CYP1B1 is responsible for activating PAHs
such as benzo(a)pyrene (BaP) and estradiol to carcinogenic intermediates. We cloned 2 full length
alleles of CYP1C1 cDNA Fundulus heteroclitus. The full-length cDNA contained a 5’ non-coding
region of 182 bp, an open reading frame of 1590 bp and a 3’ non-coding region of 988 bp to the
polyA tail. The 529 amino acid protein shared the highest amino acid identity with Stenotomus
chrysops CYP1C1 (81%). We used realtime PCR to quantitatively measure tissue and gender
specific expression of both CYP1C1 and CYP1A mRNAs in BaP exposed adult fish. CYP1C1
mRNA expression was constitutively higher than CYP1A in brain, spleen, eye and gonad, while
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Health Sciences
CYP1A was higher in GI, heart, gill and liver. Kidney had equal but high expression of both
CYP1s. There were sex differences in CYP1 expression in GI, liver, gill, and eye. BaP exposure
caused induction of CYP1C1 expression in female and male heart (31 and 17-fold), gill (7 and 4fold) and liver (6 and 5-fold), respectively. We used a 666 bp CYP1C1 digoxigenin-labeled
antisense cRNA fragment to do whole-mount in situ hybridization using freshly hatched Fundulus
(18 days postfertilization) which had been exposed to waterborne BaP (10 µg/L) for the initial 10
dpf. Results suggest that BaP enhanced Fundulus CYP1C1 expression inside the abdominal
region compared with DMSO treated embryos. On going study is aimed at determining the
specific cell types where CYP1C1 is expressed. Our results imply that teleost CYP1C, in addition
to CYP1A, is inducible by BaP, has a broad tissue distribution, and should be further investigated
for its role in carcinogen bioactivation.
51) ETHANOL PERTURBS ALCOHOL METABOLIZING ENZYME MRNA EXPRESSION
DURING MEDAKA EMBRYOGENESIS
Xueqing Wang and Asok K. Dasmahapatra. Department of Pharmacology, National Center
for Natural Product Research, Environmental Toxicology Research Program, School of
Pharmacy, University of Mississippi, University, MS 38677
Fetal alcohol syndrome (FAS) is a suite of birth defects observed in the newborn babies of
mothers who consumed alcohol during pregnancy. FAS phenotypes are identified by prenatal
and postnatal morphological defects, central nervous system disorders and a distinctive pattern of
cardiovascular, facial and limb defects. The molecular mechanism by which ethanol perturbs
embryonic development in utero has not been characterized. However, induction of oxidative
stress due to ethanol metabolism is believed to be a mechanism of embryonic ethanol toxicity.
Ethanol is metabolized primarily through alcohol dehydrogenase (ADH) pathway. These events
generate free radicals, which may cause structural or functional damage to the gene(s) in embryo.
Epidemiological studies have pointed to polymorphism in ADH and aldehyde dehydrogenase
(ALDH) gene loci as one of the potential reasons for the susceptibility to ethanol action among
humans. We, therefore, hypothesize that ethanol may modulate ADH / ALDH gene function
during embryonic development and induces FAS. We have used Japanese medaka (Oryzias
latipes) developmental system as our experimental model. Previously, we have observed that
medaka embryos express two Adh mRNAs during embryogenesis, and the expression patterns
remain unaltered after ethanol treatment. We have extended our investigation to ALDH enzyme
system. We have partially cloned two ALDH enzyme mRNAs from the developing embryos of
Japanese medaka. Phylogenetic analysis of the deduced amino acid sequences of the ALDHs
identified them as the orthologues of mammalian Aldh2 and Aldh9 genes. They have shared 31%
amino acid identity with each other. RT-PCR analysis shows that Aldh9 mRNA expression is
ubiquitous in all the organs tested, however, Aldh2 mRNA shows tissue-specific expression.
Both Aldh2 and Aldh9 mRNA expressions are developmentally regulated; low level in early
stages of development and significantly increased at the time of hatching. Ethanol treatment to
the embryos early during development has changed the expression pattern of both Aldh2 and
Aldh9 mRNA, which suggest that ALDH enzymes are the key players in FAS induction.
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Math & Computer Sciences
Math and Computer Sciences
8) IMPROVING THE PERFORMANCE OF RECURSIVE FEATURE ELIMINATION TO
SELECT RELEVANT GENES IN MICROARRAY DATA
Yuanyuan Ding and Dawn Wilkins. Department of Computer Science, University of
Mississippi, MS.
DNA microarray technology allows the analysis of thousands of genes simultaneously. Cancer
diagnosis based on DNA microarray analysis faces the challenge of the “curse of
dimensionality”, where the number of genes (features) is far more than the number of patient
samples. Feature selection is essential to reduce the dimension of a data set and thus improve the
performance of classification for cancer diagnosis. Recursive feature elimination with support
vector machines (RFE-SVMs) has been empirically observed to have excellent classification
results. But the disadvantage of RFE-SVMs is that it is time-consuming and computationally
expensive. This paper proposes several variants of RFE-SVMs and applies these variants to
cancer diagnosis data to extract genes. Comparisons between the variants and the original RFESVMs in terms of prediction accuracy rate and computational requirement are made. The results
show that the new algorithms are much more efficient while maintaining excellent classification
accuracy. The genes selected by RFE-SVMs and the variants are also compared in order to
investigate whether common or overlapping genes among those selected. Experimentation has
been done with cancer data, but the same methods will work with any gene expression data.
26) A RELAXATION ADAPTIVE MEMORY PROGRAMMING (RAMP) APPROACH TO
ADDRESS THE CAPACITATED MINIMUM SPANNING TREE (CMST) PROBLEM.
Frank Mathew1, Cesar Rego1, Fred Glover3. 1School of Business Administration, University
of Mississippi, University, MS 38677; 2Leeds School of Business, University of Colorado,
Boulder, CO 80309-0419.
Fundamental to the design of communication networks, the Capacitated Minimum Spanning
Tree (CMST) problem has been extensively studied. Relaxation Adaptive Memory Programming
(RAMP) is a relatively new metaheuristic approach that capitalizes on primal-dual relationships
coupled with the adaptive memory programming structure of approaches like tabu search. We
exploit variants of the RAMP approach to the CMST problem and present comparative results
with state-of-the-art algorithms.
31) STOCHASTIC ANALYSIS OF INTERNAL NOISES IN GENETIC TOGGLE SWITCH
Mohammed, A. K.1, Wei-Yin Chen2, and Michael Mossing3. 1Department of Electrical
Engineering, 2Department of Chemical Engineering, 3Department of Chemistry and
Biochemistry, University of Mississippi, University, MS
It is believed that modeling of simple genetic circuits will improve the understanding and design
of complex, autonomous, programmable regulatory genetic structures referred to as genetic
applets. Genetic regulatory processes often exhibit internal noises in their populations because
the interpretation of their complex nature is commonly approximated by only a manageable
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Math & Computer Sciences
number of variables. Many system characteristics such as multi-stability and threshold of steady
state switching have not been critically assessed in the presence of internal noises.
The objectives of the present work are to analyze, model and simulate the stochastic nature of a
gene expression mechanism by resorting to modern stochastic algorithms. The system involves
two mutually inhibitory genes; i.e., the protein synthesized from the expression of one gene is
capable of switching off the expression of the other gene. The master equation of this "toggle
switch" is formulated through the probabilistic population balance around a particular state by
considering five mutually exclusive events. The equations governing the means, variances and
covariance of the random variables have been derived by the system-size expansion of the
nonlinear master equations. Simulations have been conducted by solving these ordinary
differential equations simultaneously along with published rates data and by Monte Carlo
procedure, which yield the means and the minimal uncertainties of these populations inherent in
the genetic toggle switch. It is also demonstrated that the probability of noise-induced transition
from one steady state to another under the influence of internal noise can be easily estimated
based on the fluctuation envelopes derived from this procedure. These results will enhance the
design of the toggle switch as they provide constraints for the development of robust genetic
models in the presence of appreciable internal noise.
58) DRA ANALYSIS USING SIMPLE AND FLEXIBLE FDTD SUBGRIDDING SCHEME
Yizhe Zhang, Ahmed A. Kishk, Allen W. Glisson, and Alexander B. Yakovlev. Department
of Electrical Engineering, University of Mississippi, University, MS.
Various electromagnetic computational problems can be solved effectively by the FiniteDifference Time-Domain (FDTD) method. When structures contain sharp discontinuities or
electrically small objects, the FDTD computational region needs to be discretized with fine
mesh. If the mesh size is reduced throughout the FDTD computational domain to deal with such
a situation, extensive computational resources, such as memory and time, are required. To
overcome this problem, the subridding method for local mesh refinement was proposed to
increase the accuracy without increasing the numerical cost significantly. In this paper, an
efficient algorithm is presented to incorporate local finer grids for small subvolumes that contain
small discontinuities or high dielectric constant materials. Interpolation between both electric and
magnetic fields around the interface of the main grid (MG) and the local grid (LG) is used to
approximate the MG-LG interface fields in the proposed subgridding scheme. As an example,
dielectric resonator antennas (DRA's) operating in waveguide or free space are studied here by
using the proposed subgridding scheme, which enables tuning the DRA parameters such as probe
length and position in order to achieve the required matching bandwidth and radiation
characteristics. Performance of the 3-D algorithm is validated numerically on a DRA as an
example that has the high dielectric constant and the finer dimensions of the probe and the
coaxial cable.
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Social Sciences
Social Sciences
20) THEY ARE WHAT YOU EAT: A LOOK AT THE RELATIONSHIP BETWEEN
PARENT-CHILD EATING HABITS
Christy Jayne, April Mullins, Stefanie Gadd, Rhonda Merwin, and Karen Christoff.
Department of Psychology, University of Mississippi, University, MS.
As the rate of overweight and obese adults grows towards epidemic proportions, America is
quickly beginning to adopt the infamous “Supersize It” motto. Over 64% of American adults are
considered overweight and half of those people are considered to be obese (American Obesity
Association, 2004). Unfortunately the trend is moving down to the next generation with
childhood overweight up 50% from 1991 (Borra, Kelly, Shirreffs, Neville, & Geiger, 2003).
Thus intervention and prevention of childhood obesity is necessary. In designing empiricallysound programs, it is important to isolate factors affecting behaviors that have been linked to
childhood overweight. While there are many elements of weight, children’s eating habits,
especially the development of those eating habits, is one important aspect. Parents typically
influence children’s food preferences and food consumption habits (Birch & Fisher, 1998). It has
been hypothesized that a child’s food environment predicts food choices and that early
experiences are important in that repeated experiences with foods can enhance a child’s
preference for those foods (Oliveria et al., 1992). The current study expands on that hypothesis
by examining the relationship between parents and their child’s size and self-reported eating
habits.
Thirty-one three- to six-year old children and their parents participated in this study. Height and
weight were recorded for children. Parents completed a demographics questionnaire and kept a
food and activity diary for themselves and their child for a period of one week. Two stepwise
regressions were performed. The first examined factors that predict a child’s eating habits. The
second regression considered predictors of parents’ eating habits. An independent t-test
examined perceived healthy and non-healthy parents on both parents’ eating habits. Implications
of the findings will be discussed.
23) THE EFFECT OF SOCIALIZATION ON PHYSIOLOGICAL CHANGES (BODY
COMPOSITION, HEART RATE, AND RATE OF PERCEIVED EXERTION) DURING A
COMMUNITY-BASED AQUATIC EXERCISE PROGRAM FOR ADULTS 55 YEARS
OR OLDER
Suzanne Lacey, JA Suter, RS Staten, KR Beason. Department of Health, Exercise Science
and Recreation Management, University of Mississippi, University, MS.
Purpose: This study examined the effect of socialization during exercise on body composition,
heart rate and rate of perceived exertion in a sixteen-week community-based aquatic exercise
program. Methods: 19 subjects (aged 74.3 ± 6.7) performed aqua-jogging in the deep end of the
pool with the aid of a buoyancy belt and chest-level water walking at the shallow end of the pool.
Exercise sessions included a warm-up and cool-down with a 30-minute metronome driven
exercise session. The metronome count encouraged the subjects to exercise at a low-to-moderate
aerobic intensity (40-60% of HRmax, 10-16 RPE). Heart rate (HR) was measured using Polar
heart rate monitors; socialization (SOC) affects were measured via direct covert observation by a
research assistant. Borg’s Rating of Perceived Exertion (RPE) scale, which measures self
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Social Sciences
perceived exertion, was used to determine intensity levels. Weight, body mass content, percent
body fat and lean muscle mass were measured pre and post-intervention via dual x-ray energy
analysis (DXA). Results: Paired t-tests indicate that subjects reached target heart rates (THR)
while socializing with others during exercise. Moreover, results indicate that low to moderate
aerobic exercise performed in water over 16 weeks significantly (p < 0.05) reduced % body fat
(p = 0.023) and increased lean muscle mass (p = 0.006). Conclusions: Adherence to a
community based aquatics exercise program appears to increase lean body mass and reduce %
body fat in older adults. Heart rates of individuals or pairs reached their THR during the exercise
regimen protocol. Therefore, community based aquatic exercise programs allowing older adults
to socialize with minimal exercise leadership may be an effective aerobic fitness regimen. Future
studies should explore how low to medium aquatic exercise in social settings are attenuated by
various factors including age, condition, gender, and physical fitness levels.
39) IS AQUTIC EXERCISE AN ANTIDEPRESSANT FOR OLDER ADULTS?
Shea Staten, JA Suter and KR Beason. Department of Health, Exercise Science and
Recreation Management, University of Mississippi, University, MS.
Moore, et al., (1999) found that low levels of physical activity among older adults is linked to
moderate to severe depressive symptoms, and conversely regular physical activity is linked to
fewer depressive symptoms among older adults. This study examined pre- and post- depressive
symptoms of 21 subjects (aged 73 + 7.6) consisting of 5 males and 16 females who participated
in a sixteen-week, low-to-medium impact water jogging program that allowed interactions with
the other participants. Each subject was administered the Life Satisfaction Scale (LSS) & Free
Time Boredom (FTB) which measured depressive symptoms. PURPOSE: It was hypothesized
that a sixteen-week low to moderate community-based AEP would significantly affect selfefficacy measured factors related to depression in older adults. METHODS: The LSS measured
the subjects’ perceived satisfaction with life. Low scores of life satisfaction have been linked to
the development of depressive symptoms (Koivumaa-Honkanen, et al., 2004). The FTB
measured subjects’ level of perceived boredom. Boredom experienced in an individual’s free
time has been linked to depression (Ejaz, et al., 1997). Therefore, high scores of perceived life
satisfaction and low scores of free time boredom are indicators of lower depression. RESULTS:
Results of paired t-tests indicate participation in a low-to-medium impact water jogging program
that allowed interactions with other participants resulted in significantly higher levels of life
satisfaction and lower levels of boredom among older adults. The results suggest both genders
experienced significantly (p<.05) decreased factors of depression (M = 107.40) (F = 99.36) upon
completion of the sixteen-week AEP. CONCLUSION: The results are not generalizeable; they
do suggest that exercise programs that allow for social interaction among participants result in
positive effects on factors related to depression. Furthermore, the results indicate communitybased recreation programs may reduce the risk factors of depression. Future studies should use a
control group for comparison purposes and explore age, condition, and ability factors.
45) PRESCHOOL CHILDREN’S ACTIVITY LEVELS: RELATIONSHIPS TO PARENTS’
SELF-REPORTED EXERCISE HABITS AND ATTITUDES TOWARD EXERCISE
Christina Tucker, Christy Jayne, & Karen Christoff. Department of Psychology, University of
Mississippi, MS, 38677.
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Social Sciences
Childhood obesity is at an all time high in the United States (Troiano, 1998). While decreasing
the prevalence of overweight children is important, prevention of childhood obesity is essential.
In order to design empirically-sound prevention programs, it is important to isolate factors
affecting behaviors that have been linked to childhood overweight. The level of physical activity
that a child engages in is an important aspect to consider. Children are now spending more time
in sedentary activities, such as watching television and playing video games (Borra et. al, 2003).
Research has found that parents play a role in developing and encouraging children’s activity
level (e.g., McMurray et. al, 1993; Anderssen & Wold, 1992). However, it is less clear as to
when this begins to occur in a child’s life. The current study examines the relationship between
parents’ attitudes on exercise and self-reported exercise habits and their pre-school age child’s
observed and parent-reported activity level. This study is unique in that most research looking at
the relationship between parents’ and children’s activity levels has been done on an older
population of children.
Fifty three- to six- year old children were observed on three different occasions during their freeplay period. Their parents completed the Exercise Benefits and Barriers Scale (EBBS) and kept
an exercise log for a period of one week. Three separate stepwise regressions were performed.
The first looked at significant predictors of children’s observed activity at school, F (1, 32) =
4.741, p = .037. The second regression looked for significant predictors in children’s reported
activity at home, F (1, 32) = 5.094, p = .031. The third regression examined predictors of
parent’s reported physical activity, F (1, 32) = 4.207, p = .049. Implications of the findings will
be presented.
46) VALUED LIVING, EXPERIENTIAL AVOIDANCE AND PSYCHOLOGICAL WELLBEING
Jessica G. van Dyke, Leslie J. Rogers and Kelly G. Wilson. Department of Psychology,
University of Mississippi, University, MS.
Valued living in psychotherapy interventions has been a much focused upon topic for the last
few years. To date, little is known empirically about the relationship between valued living
across multiple domains and psychological distress. From a behavior analytic perspective, it is
argued that a rich engagement in these valued living domains means that the individual is in
touch with reinforcers in his life. Thus, as a direct result of reaping the benefits of reinforcers in
one’s life, it is thought that this attenuates the effects of psychological distress. However,
clinically this may not always be the case. Wilson and Murrell suggest that extreme responders
in either direction have often been found to lack behavioral flexibility. As a result, individuals in
clinical settings report experiencing psychological distress. The current study investigates the
influence of valued living and behavioral consistency with respect to one’s values and their
influence on psychological well-being. In addition to investigating valued living as a buffer to
psychological distress, we will also discuss how psychological well-being is impacted by
extreme responses on the valued living questionnaire.
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Social Sciences
52) MODELING THE ANXIETY-DEPRESSION CONTINUUM HYPOTHESIS IN
DOMESTIC FOWL CHICKS.
Jason E. Warnick1, Kenneth J. Sufka1,2,3, Matthew W. Feltenstein1, Edmund O. Acevedo4,
Heather E. Webb4 and Courtney C. Cartwright1. 1Department of Psychology, 2Department of
Pharmacology, 3Research Institute for Pharmaceutical Sciences, 4Department of Health,
Exercise Science and Recreation Management, University of Mississippi, University, MS.
Anxiety and depression are currently classified as separate clinical syndromes despite
considerable similarities in their symptoms, pathophysiological substrates and response to
treatment interventions. An alternative construct views anxiety and depression along a
continuum that we show can be simulated in an animal model. In Experiment 1, we used
socially-raised young domestic fowl separated from conspecifics to show a pattern of distress
vocalizations that sequentially models anxiety-like and depressive-like states. In addition, we
provide evidence that the model can detect and differentiate the anxiolytic and/or antidepressant
effects of the benzodiazepine anxiolytic chlordiazepoxide and tricyclic antidepressant
imipramine. In Experiment 2, we quantified corticosterone levels across the isolation test
session in order to provide convergent validity to the model. These findings fit well with the
human clinical literature on an anxiety-depression continuum perspective and suggest the
consideration of a nosology that emphasizes the interrelatedness of theses clinical states rather
than their boundaries.
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