STRATA

STRATA, the STudent Research, Academic, and Talent Archive, is a collection of selected Fort Lewis College student work, including undergraduate research, senior seminar papers, published works, conference presentations, and other creative and artistic projects. Search by name, subject, title, or academic department.

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The Effects of Invasive Shrub Tamarix on Riparian Arthropod Communities
Riparian areas in the southwest United States have been invaded by the invasive shrub Tamarix ramosissima, which has displaced native vegetation, created monotypic stands, and reduced biodiversity, among other impacts. The effect on the arthropod community, however, is still unclear, with many different studies showing either little effect or a lessened abundance and diversity. Our study sought to determine the effect of Tamarix compared to two different native counter-part habitats: a willow (Salix exigua) habitat and a shrub (Atriplex canescens, Sarcobatus vermiculatus, Gutierrezia spp., and Forestiera pubescens) habitat. 30,913 arthropods were organized into over 300 different taxa in 7 different 48 hour pit trapping sample periods, with 3 habitat types, each with 3 replicate sites. We found that Tamarix had no effect on arthropod abundance. Shrub had a higher Shannon-Wiener diversity index, but Tamarix and willow habitats did not significantly differ. Functional feeding groups (predator, herbivore, omnivore, and detritivore) did differ significantly between habitat types at different dates in the season. Also a NMS ordination showed that all three habitat types represent unique arthropod communities, with different taxa making up the abundance in each. Our overall conclusion is thus: Tamarix does not decrease arthropod abundance or diversity, but does form its own unique community of arthropods different from native counter-part habitats.
The Effects of Lake Powell on Sediment Aggradation in the Lower Reaches of the San Juan
This study focuses on the Lower San Juan River in Southeastern Utah between Government Rapid at river mile (RM) 63.9, to Clay Hills at RM 83.5 (river miles after Whitis and Martin, 2009). Here we document the on-lapping layers of sediment that have been aggrading upstream from Lake Powell since the drop of the reservoir and the effects on stream morphology. The decrease in stream gradient in this reach has apparently induced a self-reinforcing feedback that slows current and increases sediment storage in the river channel. Repeat photography that contrasts pre-dam photographs from Miser (1921) and other sources was conducted at 11 locations. In the most upstream reach studied, from Government Rapid to the mouth of Slickhorn Canyon (RM 63.9 to 66.5) repeat photography at four locations (RM 63.9,64.4,64.41,and 66.5) indicates no vertical change from aggradation has occurred. The rapid which existed at the mouth of Slickhorn canyon is now gone, but repeat photographs show that there has not been aggradation outside the previous channel. Directly downstream of Slickhorn Canyon, there is a noticeable change in stream bank material and vegetation, along with an addition of sandbars located within the river channel. Along with these changes, the elevation of the water surface and sandbars at low flows (550-800cfs) are significantly higher than surveyed channel elevations from Miser (1921). Two miles below Slickhorn at Grand Gulch (RM70.5) the channel is now 24 ft. above 1921 and 1955 levels. Below Grand Gulch the thickness of post dam sediment increases to a maximum thickness of 80 ft. by RM 82, with location (RM) and thickness in feet as follows: RM70.5 +26.5', RM71.9+38.4', RM76+57.5', RM76.5+56.1',RM76.9+55.1,RM78.5+60', and RM82+80'. These new data combined with previous surveys (Miser, 1921 and the 1986 Lake Powell Sediment Survey) delineate the thickness of the sediment wedge. The resultant lower stream gradients are correlated with a shift in stream bank vegetation types from willow-dominated (Salix exiqua) to seep-willow and reedgrass-dominated (Baccharis salicina and Phragmites australis). This documented case of sediment aggradation has implications for the hydrology, stream morphology, aquatic and riparian ecology of river systems that are upstream of reservoirs.
The Effects of Local and Global RNA Stability on Frameshift Efficiency in the HTLV-II Gag-Pro Frameshift Site
Ribosomal frameshifting is defined as a shift in reading frame. During translation, a ribosomal frameshift (FS) can occur when the ribosome encounters a slippery sequence followed by a stable secondary structure. A slippery sequence specifically allows for the opportunity for tRNA repainring with the codons in the A- and P- sites of the ribosome. Retroviruses include programmed ribosomal frameshift (PRF) sites within their RNA, which increase viral genomic coding capacity by allowing translation of multiple reading frames from a single RNA. Human T-cell leukemia virus type-II (HTLV-II) uses PRF sites to translate its enzymatic proteins. These proteins are encoded in the pro and pol open reading frames. The first HTLV-II PRF site is located at the end of the gag open reading frame and is described as the gag-pro PRF site. This FS site contains a heptanucleotide slippery sequence (AAAAAAC) followed by a stem-loop structure. Recently, a study showed that local stability of the secondary structure was correlated to frameshift efficiency in HIV-1. We hypothesize that local stability has greater control of frameshift efficiency than global stability in the gap-pro PRF site in HTLV-II. To test this hypothesis, five variant stem-loops were designed to decouple local and global stability. There variant frameshift sites were inserted into a dual-luciferase reporter plasmid using molecular cloning techniques. Successful cloning was verified by DNA sequencing. These plasmid DNAs will be used for in vitro transcription of RNA. The resulting RNAs will be purified and utilized in an in vitro translation assay to determine the frameshift efficiencies for each variant frameshift site. Finally, the frameshift efficiencies will be compared to each other to determine if local or global stability has a stronger effect on frameshift efficiency.
The Effects of Media Violence on Fort Lewis College Students
We investigated whether there was a correlation between perceived media violence and aggressive behavior. 151 pre-video media violence surveys and 151 post-video response surveys were administered. The surveys were administered to Fort Lewis College students by investigators. Students filled out the pre-video media violence survey and then were shown one of two videos. The control group watched the "The Most Heartfelt & Inspiring Commercial Ever made" video, whereas the experimental group watched the "MMA Fight Videos-knockouts, takedowns, submissions" video. Both groups filled out the post-video response survey to the video they watched. We collected the surveys and analyzed the data to see whether there was any correlation between the perceived media violence and aggressive behavior. We found overall that the Heartwarming video had a more positive emotional effect than the MMA wrestling video. A two-tailed Independent t-test was conducted and found a significant change in the effect of the film clip on the participants, emotional change, and emotions felt the most. Also participants reported that the media did not influence them to want to cause harm. A limitation of our study is that we had to use a less powerful violent film clip than we had wanted due to ethics concerns. Our study shows that prosocial videos can exert powerful influences on people's emotions.
The Effects of Mountain Pine Beetles on Lodgepole Pine Stands in Colorado
Lodgepole pine stands (pinus contorta) throughout Colorado have recently experienced an increase in mountain pine beetle (MPB) attacks, which has led to heightened tree mortality in affected regions that are directly tied to these attacks. Decreased frequency of cold days and warmer winter temperatures is what has allowed for MPB's to overtake entire pine forests. The mountain pine beetle has instigated billions of tree deaths from Mexico to Alaska since 2000 and it continues to harm pine stands to this day. Although there are still many unknown aspects of the mountain pine beetles' (dendroctonus ponderosae) existence it has been proven that the increased reproduction rate that is occurring in mountain pine beetles can be broadly attributed to climate change. It is known that there are three main factors that contribute to the success of mountain pine beetles: density of large trees, drought, and warmer temperatures, which are all factors presented by the effects of climate change. According to a study done on the effects of the mountain pine beetle, these infestations have changed surface fuel and wildfire hazards, vegetative compositions, converted live carbon sinks to dead and slowly decaying carbon sources, impacted nutrient cycling and water quality, shifted evapotranspiration and albedo, modified local surface energy balance, and changed regional climate. Many researchers have been exploring ways to successfully enact strategies that mitigate, suppress, and regenerate lodgepole pine forests that have been overcome by mountain pine beetles. This research aims to discover the effects the mountain pine beetle has on lodgepole pine species in Colorado and how those issues relate to changes in climate and ecosystem services of the affected areas.
The Effects of Outdoor Pursuits' Trips on Participants' Interpersonal Communication and Sense of Fear
The Outdoor Pursuits (OP) program at Fort Lewis College (FLC) provides students with an accessible and inexpensive way to access outdoor gear and guided field experiences.This study examined the effects of an OP trip on participants' interpersonal communication skills and their sense of fear. The study utilized a pretest-posttest design. Consenting participants completed a Likert scale survey before and after an OP trip during the winter of 2013. The subjects consisted of FLC students who are active OP members and students who were not part of the OP program. Results suggest that students who participate in an OP trip have significantly (p=.001) more interpersonal communication skills afterwards. The results also concluded that with repeated measures, the program does not show statistical significance (p=.06) in interpersonal communication skills. The results also concluded that there was no relationship between OP and its participants sense of fear (p=.016). The results also indicate that, after repeated measures, that there is no relationship between pre and post trips (p=.14) and the reduction of participants sense of fears. The conclusion from this study allows for OP to recognize how to best suit their participants needs.
The Effects of Polymem Sportswrap® on Neurological Sensation
Background: PolyMem® is used in the athletic field for the care of wounds. The use of this dressing demonstrates a much faster rate of healing than using no dressing at all (Beam, 2008). It has a high absorbency in a wound and has been known to drastically decrease pain (Burd et al., 2007). It does this by absorbing sodium ions from the skin, decreasing nerve conductance in the wound (Beitz et al., 2004). It is important to know if sensation is compromised before an athlete participates in his or her sport. Performance could be jeopardized and an athlete could be injured further. Purpose: The purpose of this study was to test neurological sensation with the use of PolyMem Sportswrap®. Hypothesis: It was hypothesized that sensation would change after a 5 day use of the PolyMem® wound dressing. Subjects: Subject selection included a healthy population from Fort Lewis College. Fifteen people, ages 18-23 were tested (4 males, 11 females). Methods: A single random group was tested via two point discrimination and deep tendon reflex on the brachioradialis after the use of control (no wrap used), gauze wrap, and PolyMem Sportswrap®. Independent variables were time, treatment, and condition. Dependent variables were the points felt and reflex grade. A two factor ANOVA with repeated measures statistical analysis was used. Results: Significance was found across time within groups in both the two point discrimination (P = 0.00) and deep tendon reflex (P = 0.01). These findings show that the use of PolyMem Sportswrap® altered sensation. Therefore, the hypothesis was accepted. Conclusions: This study found that neurological sensation changes with the use of PolyMem®. It is possible that the placebo wrap increased the activation of the sensory receptors, heightening their response. However, the PolyMem Sportswrap® returned the activation levels of the sensory receptors to normal levels. PolyMem® has an effect on both afferent input as well as efferent response. PolyMem® has been described as creating a healthy environment for healing (Beam, 2008). The results of this study provide insight that PolyMem® does not only have a local effect on the tissues, but also a systemic change in the response to an area.
The Effects of Prescribed Fire and Thinning Restoration Treatments on Forest Floor Fuel Loading in Warm/Dry Mixed Conifer Forests in Southwestern Colorado, USA
Warm/dry mixed conifer forests are dominated by fire-tolerant ponderosa pine (Pinus ponderosa), Douglas-fir (Pseudotsuga menziesii) and mesic species such as white fir (Abies concolor), and aspen (Populus tremuloides). Fire suppression over the last century has caused an increase in tree density and a shift towards mesic species moving the forest away from its historical make-up (Korb et al., 2012). Fuel-reduction treatments are one of the highest priorities in the management of western United States forests today (Kobziar et al., 2006). Fire treatments can lose their effectiveness within 10-20 years if regeneration densities are not controlled (Battaglia et al., 2008). Fire may be the best tool available for land managers to fight wild fires, and restore historical fire regimes and forest structure.
The Effects of Pulmonary Hypertension on Athlete Performance in Cyclists at High Altitude
The adverse effects of high altitude on the performance level of endurance athletes is widely recognized, yet under researched. The purpose of this study was twofold. Firstly, to identify significant changes in power output (watts) and pulmonary vascular resistance (PVR) between medium (1,981m) and high (3,139m) altitude. Secondly, to determine if a correlative relationship existed between changes in PVR, and power output (watts), when endurance cyclists performed a VO2max test at medium and high altitudes. Elevated PVR values are indicative of pulmonary hypertension, which reduces right ventricular outflow tract velocity, and may decrease O2 exchange rate. The validated model utilized to calculate PVR was as follows: PVR (dynes-cm-sec-5) = 1.2 x 80 x (PASP/right ventricular outflow tract VTI). Doppler measurements were taken prior to the VO2max test and were repeated immediately post exercise prior to acquiring two-dimensional image and again after two-dimensional image acquisition at the tricuspid valve to assess peak regurgitation velocity. The cohort included 8 subjects with a PVR of 190.41 +/- 48.64(dynes-cm-sec-5) at medium altitude and a PVR of 177.38 +/- 24.59(dynes-cm-sec-5) at high altitude. The cohort demonstrated a Power Output of 354.38 +/- 51.51(watts) at medium altitude and a Power Output of 311.88 +/- 43.75(watts) at high altitude. The paired T-test for two sample means demonstrated a statistically significant decrease in power output (p = 0.054-2), and no significant changes (p = 0.169) in relative PVR. There was a moderate correlation between max Power Output and PVR (r = 0.48) at medium altitude as well as a weak correlation between max Power Output and PVR (r = 0.27) at high altitude. This research aims to extend high altitude cardiopulmonary physiological research from medical to elite athlete populations.
The Effects of Pulmonary Hypertension on Athlete Performance in Cyclists at High Altitude
The adverse effects of high altitude on the performance level of endurance athletes is widely recognized, yet under researched. The purpose of this study was twofold. Firstly, to identify significant changes in power output (watts) and pulmonary vascular resistance (PVR) between medium (1,981m) and high (3,139m) altitude. Secondly, to determine if a correlative relationship existed between changes in PVR, and power output (watts), when endurance cyclists performed a VO2max test at medium and high altitudes. Elevated PVR values are indicative of pulmonary hypertension, which reduces right ventricular outflow tract velocity, and may decrease O2 exchange rate. The validated model utilized to calculate PVR was as follows: PVR (dynes-cm-sec-5) = 1.2 x 80 x (PASP/right ventricular outflow tract VTI). Doppler measurements were taken prior to the VO2max test and were repeated immediately post exercise prior to acquiring two-dimensional image and again after two-dimensional image acquisition at the tricuspid valve to assess peak regurgitation velocity. The cohort included 8 subjects with a PVR of 190.41 +/- 48.64(dynes-cm-sec-5) at medium altitude and a PVR of 177.38 +/- 24.59(dynes-cm-sec-5) at high altitude. The cohort demonstrated a Power Output of 354.38 +/- 51.51(watts) at medium altitude and a Power Output of 311.88 +/- 43.75(watts) at high altitude. The paired T-test for two sample means demonstrated a statistically significant decrease in power output (p = 0.054-2), and no significant changes (p = 0.169) in relative PVR. There was a moderate correlation between max Power Output and PVR (r = 0.48) at medium altitude as well as a weak correlation between max Power Output and PVR (r = 0.27) at high altitude. This research aims to extend high altitude cardiopulmonary physiological research from medical to elite athlete populations.
The Effects of Religiosity and Spirituality on Guilt and Self-Esteem
Spirituality in college-age students is a diverse and interesting aspect of life because most college students are just leaving their families, their parents' belief systems, and trying to define their own. The present study examines the relationships between spirituality, religiousness, guilt, and self-esteem. The first hypothesis proposes that there is more guilt found in people who are more religious and spiritual. The second hypothesis is that people who are religious and spiritual will have a lower self-esteem than those who are only spiritual or neither. The third hypothesis proposes that those who are religious but feel abandoned or disconnected from God will be guiltier than those who are religious and feel close to God.It was found that religion and spirituality levels did not affect the guilt levels unless the person felt abandoned. When a religious person felt abandoned, higher levels of guilt were found. Religiosity is positively correlated with self-esteem. This shows that the higher level of religion, there higher the self-esteem. There were also correlations of lower self-esteem to those who were highly religious and felt abandoned.
The Effects of Soil Moisture Availability on Nectar Production in Three Subalpine Plant Species of the Family Ranunculaceae
In some semi-arid regions, including the Rocky Mountains of western Colorado, climate change is predicted to cause a decrease in annual precipitation and increased temperatures. Climatic variations, including soil moisture availability, could have adverse effects on plant and pollinator communities. During the summer 2013 at the Rocky Mountain Biological Laboratory, Gothic, Colorado, I investigated the effects of soil moisture availability on nectar production (i.e., nectar volume, percent sugar concentration) and floral display characteristics (i.e., nectar spur length) in three subalpine species - Delphinium nutallianum, Aquilegia coerulea, and Delphinium barbeyi. Additionally, I investigated how nectar volume varied across time and how such variations could be explained by patterns in precipitation and mean temperature. All three focal species produced higher averages of nectar volume and had higher mean nectar spur lengths in response to increased soil moisture availability. Percent sugar concentration was lower for watered A. coerulea and higher for watered D. barbeyi. Nectar volume across time appears to be associated with precipitation and mean temperature. Drier conditions negatively affect nectar production, limiting the nectar reward availability and potentially affecting the survival, fitness, and distribution of plant and pollinator communities.

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