Maryland Shared Open Access Repository
MD-SOAR is a shared digital repository platform for twelve colleges and universities in Maryland. It is currently funded by the University System of Maryland and Affiliated Institutions (USMAI) Library Consortium (usmai.org) and other participating partner institutions. MD-SOAR is jointly governed by all participating libraries, who have agreed to share policies and practices that are necessary and appropriate for the shared platform. Within this broad framework, each library provides customized repository services and collections that meet local institutional needs. Please follow the links below to learn more about each library's repository services and collections.
Browse
Communities and Collections | By Issue Date | Author | Titles | Subjects | TypeSubmit
Institutions in MD-SOAR
Select a community to browse its collections.
Recent Submissions
TREE SPECIES-RICHNESS AND TOPOGRAPHIC COMPLEXITY ALONG THE RIPARIAN EDGE OF THE POTOMAC RIVER
(1996-10) Everson, Daniel A.; Hood College Biology; Biomedical and Environmental Science
I studied the riparian forest edge of a central portion of the Potomac River in order to test
whether there is a relationship between small-scale topographic complexity of the
riverbank profile and tree species-richness. A total of 153 transects and 2568 trees were
measured along 60 miles of the Maryland side of the Potomac River corridor between
Harpers Ferry, West Virginia, and Hancock, Maryland. Five-meter-wide strip quadrats
(transects) perpendicular to the river were established systematically at 1/3-mile intervals.
Three tree species, silver maple (Acer saccharinum), boxelder (Acer negundo), and
sycamore (Platanus occidentalis), dominated the species composition of the riparian
edge. Silver maple dominated in terms of overall basal area with over 43 percent, while
boxelder dominated in terms of individuals, with over 38 percent of the stems.
Standardization of species-richness for differing sample sizes was accomplished utilizing
the rarefaction technique, which standardizes on the number of individuals rather than on
unit area. Small-scale topographic complexity was measured by calculating the standard
deviation of 2.5m slope measurements taken along the length of each transect. A
significant positive relationship was observed between tree species-richness and
topographic complexity. However, the low r2 value suggested that change in topography
at a small scale explained only a small part of the variation in species-richness. An
analysis of covariance using adjacent land use designations and underlying geology as
categorical variables, with the standard-deviation-of-slopes as the covariate, indicated that
adjacent land use and bedrock geology had no statistically significant impact on species-richness,
and that the simple linear regression model was adequate to estimate the effect
of topographic complexity on species-richness. Observations made during field work, as
well as a one-way analysis of variance between the different land use/geology groups,
and a rarefaction species-richness analysis of pooled transect data in the Conococheague
Limestone indicated that there were greater concentrations of tree species near cliffs. A
negative relationship was observed between tree species-richness and the width of the
riparian zone, and this relationship was consistent across geology. Tree species
summaries and the location of narrow riparian edges on the outside of meander bends,
suggest that this is an edge effect, due to a greater number of tree species able to take
advantage of an increased light gradient and the presence of a stable, well-drained
substrate not subjected to repeated additions of sediment.
A Study of the Effects of Stream Improvement Procedures on Benthic Macroinvertebrates
(1977-05) Evans, William Kirk; Hood College Biology; Human Sciences
The effects of stream flow alteration on benthic macroinvertebrates
and water quality were studied in two regions of Hunting Creek, a
cold water stream originating in Catoctin Mountains in northern Frederick
County, Maryland.
The study involved two sections of stream, both located in the
headwaters of Hunting Creek. One stream section was modified for the
purpose of this study by building stream improvement devices in the
stream channel; the other section of stream was maintained in its natural
condition.
Permanent collecting stations were established along each
stream segment and benthic fauna and water quality were sampled on a
regular basis. Monthly, benthic samples were collected for eight months
by means of a Surber square foot bottom sampler. Drift net samples also
were collected on three occasions during the study. Chemical and physical
features of water collected from the two study areas were measured
using standard methods for water analysis. Water samples for chemical
analysis were collected on three occasions while physical parameters were
measured each time benthic samples were collected. Random stream sampling
for benthic macroinvertebrates and water quality also was done
above and below the study areas to obtain additional data for use in
characterizing the two stream sections being studied.
The benthic faunas of the study areas were compared on the
basis of diversity, density of organisms, species composition, frequency
and dominance. The physical features used in evaluating water quality
included depth, velocity, volume and temperature. The chemical characteristics
measured were dissolved oxygen, pH, nitrate, ammonia, total
phosphate, turbidity, total hardness, conductivity, carbon dioxide and
hydrogen sulfide. Analysis of chemical and physical data failed to show
a statistically significant difference in water quality of the two stream
areas. The benthic composition of the two study areas, was found to differ
significantly with respect to diversity, density, frequency, dominance,
species composition and drift. Data from the improved stream
section showed lower values for all biological features evaluated for
benthic macroinvertebrates, regardless of stream improvement efforts.
The unimproved stream area and random stream sites located above and
below Hunting Creek Lake showed similar values that were consistently
higher than the improved stream section for all biological characteristics
evaluated for the benthic macroinvertebrate fauna.
THE EFFECTIVENESS OF A NOVEL cGMP REFRESHER TRAINING PROGRAM ON THE AWARENESS OF FEDERAL REGULATIONS IMPACTING BIOMEDICAL RESEARCH
(2011-01) Evans, Carter; Hood College Biology; Biomedical and Environmental Science
Current Good Manufacturing Practices (cGMPs) require that "each person
engaged in the manufacture, processing, packing, or holding of a drug product shall
have education, training and experience to enable that person to perform the assigned
functions (21 Code of Federal Regulations 211.25(a))." This project seeks to develop
an effective training program for the GMPs. Common issues regarding cGMP
guidelines were investigated and compiled into a database. A novel computer-based
training program in a game show format was developed linking to the question
database. This software was tested at Lonza in Walkersville, Maryland and Hood
College. Matched pair t-test analysis shows that survey matching scores improved by
almost two points on average for all participants and each trainee's self-evaluation of
his or her cGMP knowledge increased by almost one point on a ten-point scale. This
training delivered an effective and unique way of improving training compliance.
ANALYSIS OF DATA COLLECTED BY THE COMMUNITY ENVIRONMENTAL HEALTH RESOURCE CENTER (CEHRC) IN THIRTEEN HIGH-RISK INNER CITY COMMUNITIES
(2007-05) Etheridge, Connie; Hood College Biology; Biomedical and Environmental Science
PROLACTIN ACTIVATES RAS VIA SIGNALLING PROTEINS SHC, GRB2 AND SOS
(1995-05) Erwin, Rebecca Ann; Hood College Biology; Biomedical and Environmental Science
Identification of the signal transduction pathways used
by prolactin (PRL) is essential for understanding the role
of PRL receptors in growth and differentiation processes.
Early cellular mediators of PRL receptor activation include
tyrosine kinases of the JAK and SRC families, with rapid
nuclear signalling via tyrosine phosphorylated STAT
transcription factors. In the present study we provide the
first demonstration of PRL-induced activation of RAS, an
oncogenic protein that supports a separate signalling route
from the membrane to the nucleus. In rat Nb2-SP lymphoma
cells PRL stimulated RAS as detected by a 2.0-fold increase
in the GTP-bound state of the molecule (p<0.01). RAS
activation was associated with marked tyrosine phosphorylation
and increased membrane association of the 52 kDa
form of SHC. PRL induced binding of SHC to GRB2 and the
guanine-nucleotide exchange factor SOS, a common method
used by growth factor receptors to activate RAS. In
contrast, no apparent regulation by PRL of RAS via VAV or
p120 RAS-GTPase-activating protein was detected, based upon
an absence of PRL-inducible tyrosine phosphorylation of
these proteins. Collectively, these results provide a
molecular bridge between activation of PRL receptor-associated
tyrosine kinases and the subsequent stimulation
of the serine/threonine kinase RAF-1, an established RAStarget
that was recently shown to be activated by PRL in
Nb2 cells. In conclusion, PRL is able to activate RAS via
recruitment of the signaling proteins SHC, GRB2 and SOS in
Nb2 cells. Moreover, prolactin induced tyrosine phosphorylation
of SHC in two out of three PRL-responsive human
breast cancer cell lines, suggesting that SHC-mediated RAS
activation is a commonly used signalling strategy for PRL.