2010 - Welcome to the University of Guam

UOG Charter Day 2010
College of Liberal Arts and Social Sciences
31st Annual Research Conference
“Visions Beyond the Horizon”
March 9, 2010
CNAS Student Biomedical Research 2009-10
Presentations 1:00—3:00 p.m.
HSS 203
UOG NIH RISE Program
Biodiversity mural on House 28
RISE student abstracts, 2010 CLASS Research Conference
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RISE student abstracts, 2010 CLASS Research Conference
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Survival of E. coli, Salmonella and Listeria in beef marinating
in lemon juice for kelaguen.
Shayna Jo Afaisen
Biology Masters student
Jian Yang
CNAS: Family, 4H, Food & Nutrition
Kelaguen, an ethnic food of Guam, is commonly made with meat, lemon juice and vegetables.
Beef kelaguen is often prepared by marinating raw meat in lemon juice from 1:0.1 to 1:0.3 (beef:
juice) ratio for 6-10 hours. Unfortunately, kelaguen is one of the leading causes of the high
foodborne illness occurrence on Guam. In a kelaguen survey, 52% participants accepted the
concept that lemon juice can eliminate or kill harmful bacteria for kelaguen. The survival of
pathogens in lemon is unknown. The objective of this study was to determine the survival of
Escherichia coli O157:H7, Salmonella enteritidis and Listeria monocytogenes in beef marinating
in lemon juice for kelaguen at 24°C and 4°C. Beef was inoculated with selected pathogens and
marinated in lemon juice at ratio from 1:0.2- 1:10. The beef was stored at either 24°C or at 4°C.
Marinated beef were sampled and plated on selective media. Pathogen survival decreased with
increasing concentrations of lemon juice. Marinating beef at the ratio of 1:0.2 for 10 hours
achieved a 1-2 log reduction of the tested pathogens. To achieve a 5 log reductions during
marinating beef in lemon juice for 10 hours requires a minimum ratio of 1:10 for E. coli
O157:H7 and S. enteritidis and a 1:5 ratio for L. monocytogenes. E. coli O157:H7 resisted
greater to the acid than S. enteritidis and L. monocytogenes. Marinating beef in lemon juice at
4°C enhanced the survival of tested pathogens. Marinating raw beef in lemon juice either at room
temperature or in the refrigerator is not safe to prepare kelaguen, posing a high risk of foodborne
illness.
RISE student abstracts, 2010 CLASS Research Conference
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Risk-sensitive foraging in the Brown Tree Snake
James Duenas,
Biology Masters student
Michael B. Ehlert
CLASS: Social/Behavioral Sciences
Since its accidental introduction to Guam the brown treesnake has caused irrevocable
damage to the island ecosystem. Research on the snake has focused mainly on field studies.
Furthermore there is a dearth of behavioral research on the brown tree snake, and in reptiles in
general in the laboratory setting. The current study describes a laboratory investigation of brown
tree snake foraging behavior based on methods first described by Caraco et. al. Eight wild
captured brown tree snake specimens were individually placed in a specially constructed
experimental foraging chamber containing four prey boxes located at four corners of the room.
The snakes were left to forage freely overnight, and their foraging activity for the entirety of the
session was recorded using an infrared imaging system. Snake foraging behavior was observed
the following day and cataloged on data recording sheets. Preliminary results indicate that brown
tree snakes exhibit risk sensitive foraging in accordance with existing models. The success of the
current study demonstrates the viability of the Brown Tree Snake as an experimental animal in a
laboratory setting. Future avenues of research for the Brown Tree Snake include laboratory
studies of mating behaviors and habitat selection.
RISE student abstracts, 2010 CLASS Research Conference
An evaluation of DNA extraction methods and TaBV screening of the taro collection
at the Inalajan Experiment Station
Roslynne Ebeo
Undergraduate Biology major
Dr. George Wall
CNAS: Plant Pathology
Taro (Colocasia esculenta), sometimes called the ‘potato’ of the tropics, feeds more than one
hundred million people worldwide. The presence of the Taro Bacilliform Virus (TaBV) is often
latent, but may stunt plant growth. If TaBV is combined with Colocasia Bobone Disease Virus,
it can cause alomae, a lethal disease. A polymerase chain reaction (PCR) technique to test for
TaBV was developed in 2007, but the best method for deoxyribonucleic acid (DNA) extraction
is unknown. Three DNA extraction methods were compared using random Taro samples
collected from the plant pathology laboratory nursery. These methods were Invitrogen
DNAzol®, QUIAGEN DNeasy®, and Cetyl Trimethyl Ammonium Bromide (CTAB).
Comparison was based on price, amount of sample, procedure time, clarity of DNA extraction
shown by gels, and the PCR results. CTAB was chosen as the best DNA extraction method
because of price, procedure time, clarity of gels, and the PCR results. This method was used to
extract DNA from all 45 varieties of Taro located at the Inalajan experiment station. Currently,
we are screening the collection for the presence of TaBV using the PCR technique.
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RISE student abstracts, 2010 CLASS Research Conference
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Investigating the effects of introduced deer and pigs on limestone forests
Ann Marie Gawel
Biology Masters student
Philippine deer (Cervus mariannus) and pigs (Sus scrofa) were introduced to the Mariana
Islands centuries ago. They undoubtedly have effects on ecosystems, and are identified by
natural resource agencies as a major conservation concern. However, specific effects with
regards to limestone forest plants are poorly understood. This project seeks to investigate their
effects on the plant species composition of Marianas limestone forests, which are unique habitats
with high levels of endemism. Preliminary observations and results indicate that the ecological
effects that deer and pigs have on limestone forests include increased seedling mortality and
dispersal of weedy and invasive plant species. Species specific effects on seedling mortality and
actual forest composition are yet to be investigated, but can yield important information that can
guide ungulate control and native reforestation efforts.
RISE student abstracts, 2010 CLASS Research Conference
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Identification of Pentalonia nigronervosa and Pentalonia caladii
Christina Nguyen
Undergraduate Biology major
Ross Miller
CNAS: Entomology
Aphids are destructive insect pests on cultivated plants. On Guam all aphids are alien
invasive species. One of the most serious pestiferous aphids, the banana
aphid, Pentalonia nigronervosa, can be found in areas where bananas are grown
(Musa spp.) and/or with several other plant species including those of the order
Zingiberales and those of the family Araceae. The first recorded discovery of Pentalonia
nigronervosa was made on banana trees on the Indian Ocean island of Reunion in 1859.
Almost six decades later, a second species, Pentalonia caladii, was described from
Caladium Island in Java, Indonesia. Whereas most authors believe the two to be of the
same species, others recognize variation between the two and consider them different
forms, or more recently, as distinct species. This project attempts to quantify the variation
between P.nigronervosa and P. caladii, with the goal of formulating a key that may be
used to distinguish the two species.
RISE student abstracts, 2010 CLASS Research Conference
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Increasing the diversity of conotoxin mRNA transcripts in Conus catus
Andres J. Reyes
Undergraduate Biology major
Jason S. Biggs
UOG Marine Laboratory
Cone snails (Conus) are predatory marine animals that feed on fish, marine worms, and marine
snails. Although their conotoxins are used primarily for prey immobilization and metabolism, the
diversity of these venom genes may assist in the field of biomedical research, particularly
towards the synthesis of pharmaceutical drugs. In this project, we will attempt to increase the
diversity of conotoxins encoding mRNA transcripts isolated from venom ducts of Conus catus, a
fish hunter. First, we will attempt to stimulate conotoxin gene expression by removing the
venom from snails via exhaustive milking. Complementary DNA (cDNA) pools will be created
from total RNA isolated from the venom ducts and mRNA transcripts will be amplified using
primer pairs specific to known conotoxin superfamilies expressed by fish hunters. Comparisons
between “milked” and “unmilked” transcript diversities will evaluate whether conotoxins genes
are transcribed when they are most needed; i.e., when the snail has run out of venom. This is one
of the first ecologically-relevant attempts to create a more extensive cDNA library from a
venomous animal.
RISE student abstracts, 2010 CLASS Research Conference
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Venom plasticity of captive Conus striatus
Cabrini Rivera
Undergraduate Biology major
Jason S. Biggs
UOG Marine Laboratory
The carnivorous marine gastropods in the genus Conus, or “cone snails”, are well-known in the
pharmaceutical world for producing the neuroactive peptides (conopeptides) used to capture
prey. Although it is known that each cone snail species creates a mixture of unique
conopeptides, a paucity of information exists about whether the venom within a single snail can
change – a concept we refer to as “venom plasticity”. This work provides evidence suggesting
that the venom milked from a cone snail changes in ways that increase conopeptide diversity and
thus, milking – as opposed to destructive sampling – is a strategy which increases the potential to
discover novel therapeutics. In other words, by finding ways to manipulate the appearance, as
well as the amount, of each peptide within the venom of a “farm raised and milked” snail, we can
enhance pharmacological discovery and conopeptide production for medical treatments and
simultaneously provide an eco-sustainable source to enhance further research efforts.
RISE student abstracts, 2010 CLASS Research Conference
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Social vigilance and mobbing behavior of a territorial damsefish,
Stegastes albifasciatus (Pomacentridae)
Sarah Vega-Rogers
Graduate Biology Program
The ability to recognize a potential predator and respond via antipredator behavior is
crucial to the survival of prey animals. Under the threat of predation several such behaviors have
evolved (e.g. visual and chemical alarm signaling, predator deterrence). For prey species, the
costs associated with predator avoidance should drive the development of efficient risk
assessment systems. Predator avoidance behavior is shaped by a series of trade-offs between the
benefits associated with the successful detection and escape from potential predators and other
fitness-related activities, such as foraging, mating, and territorial defense. This study will
document individual risk assessment and group mobbing behavior of Stegastes albifasciatus
(Pisces: Pomacentridae) in a territorial mosaic by recording their territorial behavior, determining
individual territory boundaries, and the presence of clustering behavior. Clustering is important
because it will indicate a territoriality-based social system that could lead to group mobbing
against intruding predators. This mobbing is considered to be a cooperative behavior response.
Territories will be plotted in and around five by five meter nylon grid with each transect point
spaced every one meter. At randomly selected areas, a control (clear empty round container) and
several predators with different feeding methods (i.e. ambush and suction) will be introduced
using the model bottle technique. During each observation, a video camera will record the
individual reactions of each S. albifasciatus involved. From these observations, I will record
whether a mobbing group of S. albifasciatus is formed, the number of participants in the group,
and the number and magnitude of each physical attack upon the introduced predator. Each
attack, point of contact (head, trunk, caudal, mixed), distance from point of attack, and reaction
time will also be recorded. Results are expected to demonstrate cooperative mobbing behavior
in S. albifasciatus and the ability to recognize, assess, and react appropriately to potentially
hazardous predators that enter territorial mosaics of this species.
Mentor: Terry Donaldson.
RISE student abstracts, 2010 CLASS Research Conference
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The UOG NIH RISE Program and the RAs it supports wish to acknowledge their appreciation
of the time and effort the mentors put in to the students’ development as professional research
scientists.
We also wish to acknowledge funding from National Institute of General Medical Sciences
Division of Minority Opportunities in Research (NIH RISE program), the US Dept. Education
Title III (ED MSEIP Program), and the agencies that fund the mentors’ research.
Dr. María Schefter
Student Research Opportunities Coordinator
Dr. Chris Lobban
Program Director
RISE research mentors –
Dr. Jason Biggs
Dr. Terry Donaldson
Dr. Alex Kerr
Dr. Rachael Leon Guerrero
Dr. Mari Marutani
Dr. Ross Miller
Dr. Laurie Raymundo
Dr. Peter Schupp
Dr. Jian Yang
Dr. George Wall
Assisting mentors –
Dr. John Brown
Mrs. G.L. Rama Gadi
Mr. Jesse Guerrero
Mrs. Alicja Wiecko
Dr. Anne Brooke, NAVFACMAR
Dr. Haldre Rogers. Univ. of Washington
The UOG NIH RISE Program office is located in the Agriculture and Life Sciences Building,
Room 207
Priscia de la Cruz, grant assistant
Email: rise@uguam.uog.edu
Contact numbers:
Tel. (671) 735-2146
Fax. (671) 734-4600
RISE student abstracts, 2010 CLASS Research Conference
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Biodiversity mural was designed and painted by RISE students Frank Macabenta
(center; now a graduate student at Rutgers) and Sara Namazi (now a graduate student at UOG),
with help from several other Biology majors, including Marielle Terbio, Julie Anne Duay,
Kaylyn Knaeble, Eiffel John Manzano, Robert Ady, Cabrini Marie Rivera,
Laura Irene Barnhart and Maia Raymundo.
The mural represents the biological diversity of life on Guam including some organisms
that faculty and students have worked on. Spiraling in from the left:
sea horse, Guam rail, plumeria, turtle, cone snail, diatoms, and Maristentor.