STRATA

: My Name Is Hope; Short story published in the Fall 2010 - Winter 2011 issue of Images.

: Natural Product Synthesis of Diarylether Cyclophanes; Diarylether heptanoids are naturally occurring cyclophane compounds that exhibit a wide range of biological activities such as anti-cancer, anti-viral, anti-inflammatory, and antioxidant properties. The biological activities of these cyclophanes can be attributed to the strained seven-carbon tether which is largely responsible for the chirality of these macrocyclic structures. We report work towards developing synthetic strategies for a series of diarylether cyclophanes with varying degrees of conformational strain to investigate the relationship between structural integrity, barrier to racemizatoin, and biological activity. The synthesis and characterization of both seven- and eight-carbon tether cyclophanes were successful where the eight-carbon tether cyclophane is the first ever reported.

: Navajo Students' Perspectives on Tribal Food Systems and Sovereignty; The importance of tribal food systems is strongly related to the health, land, and culture of Native American people. I was interested in exploring the beliefs, knowledge, and perspectives of Navajo Fort Lewis College (FLC) students about tribal food systems and food sovereignty, and determining whether their access to traditional and healthy foods differed between the Navajo Nation and on campus. This study took place at FLC using an online survey (SurveyMonkey.com), which was advertised on the Fort announcement page and emailed to all the Native American and Indigenous students. The online survey included open/closed ended, multiple choice, Likert scale, and dichotomous questions. I collected 65 responses within a 7-day window. Results showed that majority of the participants agree that local food systems, face-to-face interaction, and farm-to-school programs are great approaches for revitalization of dietary changes for Navajo people and food sovereignty - for restoring Hózhó (state of peace and harmony, Walking in Beauty). For Navajos, it is a sacred responsibility to practice with respect and reverence to our environment, as we are interrelated and interdependent as land, plants, animals, and people. Unfortunately, Navajo student participants reported feeling separated from tribal foods and culture while at FLC. One way to address this issue is to have a garden on FLC campus for indigenous students to plant and cultivate their traditional plant-based foods. Since I found out that not all students know how to grow, maintain, harvest, or prepare traditional foods; I would also suggest having a class or workshops dedicated to practicing food sovereignty and learning about the various types of traditional foods. This study provides an increased understanding of indigenous students' perceptions of tribal food systems, and identifies ways in which colleges could improve upon delivering access to healthy, traditional foods on campus.

: Networked Autonomous Surface Vehicles for Reservoir Monitoring; On August 7, 2015 the Environmental Protection Agency accidentally released three million gallons of acidic mine drainage into Cement Creek near Silverton, Colorado. This catastrophe resulted in community, state, and world-wide alarms regarding the vulnerability of the City of Durango's water supply. A realization that this precious resource can easily be contaminated caused human-health concerns and environmental impacts to rise to the forefront of concern. This event, among other notable spills, provides motivation to examine the use of autonomous robotic systems, capable of performing real-time, remote monitoring for rapid detection and alarm. To this end, this project developed a robotic system capable of performing effective and efficient persistent aquatic monitoring. The Robotic Guidance and Control for the Observation and Monitoring of the Environment (GNOME) Lab at Fort Lewis College, as part of a senior capstone research project, designed and built a networked system of Autonomous Surface Vehicles (ASVs) to continuously monitor the water quality and quantity in the City of Durango's water reservoir, Rogers Reservoir. The robotic system is designed for future applications and deployment in other aquatic resources in the surrounding Four Corners Region as well. This network consists of three ASVs; that enable accurate spatiotemporal monitoring of a dynamic environment. The network of ASVs provides information about the physical properties of the water that enable resource managers to assess and respond in near real time to water quality concerns. The Robotic GNOME Lab is also in collaboration with international educational institutions and local elementary schools. International collaboration is to facilitate data sharing and the development of autonomous sampling and data analysis algorithms. The local collaboration is to teach local elementary students about the physical properties of fluids, water quality, robotics, and the field of aquatic robotics. The networked robotic system consists of three ASVs with custom hull designs optimized for local fresh-water reservoirs and the ability to withstand local weather and potentially low-pH (3-4) water. Each vessel optimizes power consumption for both sampling and operation to enable persistent, 24/7 autonomous operation. Typical weather in lakes and reservoirs in a mountainous environment include large temperature swings, wind gusts of 20 mph, various forms of precipitation such as hail and freezing conditions, which have all been considered in the design and construction. Autonomy is accomplished by on-board Arduino Mega 2560 microcontroller and navigation is performed by an Adafruit Breakout V3 GPS and IMU. Continuous power to the ASVs will be generated onboard with solar panels and battery storage to accomplish 24/7 continuous operation. Communication for data transfer and mission updates is handled over 3G cellular communication through a Particle Electron board. The water quality sensor suite is designed to be modular with interchangeable sensors to target specific sampling requirements for each deployment location. All collected data are posted in near real time to a publicly-available website. The intended uses of the data are to inform local resource managers and policy makers, as well as to engage the public through educational outreach and citizen scientist programs. All three ASVs are designed around a basic dual-hull catamaran design, and are roughly five feet in length, and 2.5 feet in width. ASV 1 has rectangular hulls, is heavy-duty, and impact resistant. It has a structural foam body with reinforced polyester, and hand-finished laminate. ASV 2 and 3 are cylindrical in shape, lighter, faster, and can carry more payload. These boats are made as a ribbed structure with reinforced epoxy and vacuum bag finished laminate. This second iteration of design was chosen to reduce the technicality and time of fabrication, the total weight of boat, carry more payload, and to increase stability. For power, two 50-watt solar panels collect solar energy that is stored in two 20 Ah LiFePO4 batteries. A commercial charger is used to charge both batteries and control the charging cycle. Mechanical relays are located at the grounding terminal of each battery and on the solar panels to disconnect all electrical sources if water enters the hulls or the electronics housing. The batteries are protected from a short circuit by a 15 amp fuse. The electronics for the boats are housed in a pelican case that is suspended between the hulls. An Arduino Mega was chosen to control the ASV and communicates via I2C with a Particle Electron that provides 3G cellular communication. Two Blue Robotics T200 thrusters are used to propel the boat. A thruster is mounted on the back of each pontoon to provide for differential thrust steering. GPS waypoint navigation is being used with a geo-fence. An IMU is used to provide a magnetic tilt-compensated heading while the boat is traveling at low speeds, and the GPS provides a heading when the boat is traveling at speed greater than 0.5 meters per second. Waypoints are chosen based on a sampling algorithm within the geo-fence that provides adequate spatial coverage for optimal water quality monitoring and data collection. The user can change the sampling algorithm while the ASV is deployed through a web-interface on the website. This ability to communicate to the vehicles allows collaboration with international researchers to simultaneously test sampling algorithms with all three vehicles: one vehicle to perform ground truth and the other two vehicles for testing iterations to the sampling strategy. The standard water quality monitoring sensor suite consist of temperature, pH, and salinity. These sensors have been included because they provide a fundamental picture of the aquatic environment. Each ASV is set up to accommodate up to three additional sensors, with the possibility of extending this capacity if needed. This network of ASVs will be deployed on Rogers Reservoir to monitor water quality at the Florida River and Animas River inlets, and at the outlet of the Reservoir. Real-time data will be posted on a publically accessible website and a database will be located on the Fort Lewis College server. Additional deployments will occur at regional lakes/reservoirs and in suitably-sized rivers to collect aquatic data of interest to researchers and scientists. The GNOME Lab will continue to develop and test planning and control of the network of ASVs for long-term deployment—requiring efficient data collection techniques, and cost-effective communications. This network of ASVs will eventually be coupled with autonomous underwater vehicles (AUVs) and unmanned aerial vehicles (UAVs) to form an aquatic robotic sensing system that can provide a means of understanding complex and dynamic aquatic environments.

: New Antiviral Therapies Inspired by the Study of Naturally Occurring Compounds; Natural products are organic compounds that are produced by plants, fungi, bacteria, and animals that often are used for medicinal purposes. Sattazolin is a natural product reported to exhibit potent antiviral activity, with an ID50 of 1.5 µg/mL against herpes simplex virus type 1 (HSV1) and type 2 (HSV2). New treatments for HSV infections are critical considering that much of the world population is infected with some member of the human herpesvirus family. In particular, HSV infections can be life threatening for immunocompromised patients, pregnant women, and newborns. Acyclovir and related nucleoside analogs are currently prescribed for HSV infections, but nucleoside-resistant HSV infections have become more common. Our interest in the synthesis of sattazolin was sparked by these considerations as part of a project to determine the mechanism of action of this and other antiviral natural products and analogs. In addition, we are interested in studying the activity of these acyloins against the related herpesvirus, varicella zoster, as well as other viral strains. Described here is the first total synthesis of (+)-sattazolin, which allowed for the assignment of the previously unknown stereochemistry. More importantly, experiments to unravel the unique mechanism by which sattazolin inhibits viral growth are underway and will be described.

: New Insight Into the Controls on Platinum-Group Element Mineralization in the Allard Stock, La Plata Mountains, Southwestern Colorado; The Allard stock is a mass of mostly alkaline felsic to intermediate intrusive rocks that were emplaced ~65 Ma during the formation of the La Mountain laccolithic complex. Formation of the Allard stock was accompanied by zones of mineralization that tend to be concentrated along northeast-trending fractures. Geologic surveys since the 1930s have documented the occurrence of copper mineralization within the stock along with economic concentrations of gold and silver. In addition, anomalous concentrations of platinum-group elements (PGE) have been found in some of the mineralized zones within the Allard stock. The geologic controls and origin of PGE minerals in the stock were previously unknown. One of the main hypotheses tested in this research was whether platinum-group elements were incorporated in other minerals or were distinct phases within the deposits. A detailed petrographic and geochemical investigation of mineralized zones in the Allard stock that were known to contain PGE revealed that platinum-tellurium-bismuth minerals form discrete, late-stage phases in the ore systems. These platinum minerals are spatially associated with magnetite-chalcopyrite-pyrite assemblages within the stock, but the PGE crystallized either on the margins of these iron- and copper-rich minerals or in microfractures in the rocks. PGE mineralization also has a close spatial and temporal relationship with gold and silver as indicated by Quantitative Electron Microscopy scans which reveal native gold and gold-silver telluride minerals in close proximity to the PGE minerals. This research has established that PGE and Au-Ag mineralization in the Allard stock are distinct phases the formed late in the mineralization of the intrusive mass. This style of mineralization is similar to PGE-Au-Ag mineralization in alkaline intrusive rocks in other parts of the world. Our research provides additional insight into the nature of PGE mineralization in these types of deposits.

: New Insight Into the History of the Chicago Basin Stock from U/Pb Zircon Age Constraints, Needle Mountains, Southwestern Colorado; The Chicago Basin stock (CBS) is a porphyritic granite hosted by Mesoproterozoic granite in the Needle Mountains of southwestern Colorado. Previous studies have interpreted the timing of emplacement as Oligocene or Miocene, and have documented extensive molybdenite mineralization of this stock. New U/Pb analyses on zircons from a sample at the core of the CBS reveal three zircon populations. Some of the crystals analyzed are ~1.4 Ga xenocrystic zircons contributed by melting and incorporation of the adjacent Eolus Granite. The most abundant fraction of zircons yielded an age 28.09 ± 0.36 Ma while a smaller population defined an age of 9.1 ï‚± 0.5 Ma. No distinct core to rim variations were determined in any of the zircons. The ~28 Ma emplacement corresponds to widespread regional magmatism and volcanism from 29-27 Ma related to caldera eruption. The ~9 Ma population of zircons is similar in age to fission-track zircon age previously recorded in the CBS. The Miocene zircons correspond to emplacement of small volume granitic stocks across the western San Juan Mountains some of which are also related to molybdenite mineralization. These data imply that the Chicago Basin stock was a site of at least two different events that either involved multiple generations magma emplacement or an Oligocene pluton overprinted by Miocene veins and hydrothermal alteration.

: New Insight into Volatile Sources and Magmatic Processes of Ultrapotassic Rocks in the Navajo Volcanic Field from Chlorine Isotopes and Chlorine-Fluorine Trends; The dominant bulk-rock geochemical signatures and trends of rocks in the Navajo volcanic field (NVF) are well established, but the volatile histories of these rocks are poorly defined and understood. New insight into the types and trends of volatiles rocks of the NVF reveal that magmatic gases are F rich and variable but generally Cl-depleted. NVF volatiles were derived from a source with distinctly positive

: New York Pigeon; Photograph from Fall 2010 - Winter 2011 issue of Images.

: Nitrate Loading: An Analysis of Land-Use Impacts on Topsoils Within the Rio Java Watershed, Las Cruces Biological Research Station, Costa Rica; The modification of natural landscapes to agriculture, pasturelands, and urban areas has been wide-spread throughout Costa Rica since the late 1790s. These land-use priorities have had their greatest impact on the south-central county of Coto Brus. Degradation of water and soil quality, including excess nitrate levels, is some of the resulting concerns of these practices. Four study sites (representing pasture lands, secondary/primary forests, and urban areas) were chosen within the boundaries of the Rio Java watershed (located in Coto Brus County). At the time this study was conducted, little to no research focused directly on soil NO3- in this watershed. Costa Rican soils are generally classified as Ultisols, which are characterized as having high leaching rates. The study focused on the impacts and risks associated with land-use management practices on soil NO3- in tropical environment of the Rio Java watershed. Nitrate (NO3-) concentrations, percolation rates, and nitrate loading rates (NLR) were analyzed throughout the four sites. Eighteen soil samples and percolation rate tests were conducted at each site. Subsequent topsoil pore water and nitrogen loading rates (NLR) ([NO3] mg/l * percolation rates (L/sec)= NLR (mg/sec)) were analyzed to assess the potential risk for nitrate contamination of groundwater at each land-use type. Two-way ANOVA with post-hoc Tukey tests (α=0.05) were run to determine if statistically significant differences of NO3- concentrations and NLR exist between sites. Statistically significant differences of NO3 concentrations and NLR were found between the four different land-use management sites (p=0.01). This preliminary study indicated that the secondary forest has the highest mean NLR and NO3- values >25 ppm. Soil NO3- >25 ppm is considered above sufficient for plant nutrient needs. These excessive NO3- values in conjunction with high NLR, may lead to leaching of NO3- into groundwater, posing a risk to human health and the environment.

: Nmr Metabolite Profiling of Acidobacterium Capsulatum Grown in Minimal Media with Glucose as the Sole Carbon Source; Acidobacterium capsulatum is an acidophilic chemotrophic organism first cultured in 1991. Its genome was reported in 2009. Organisms in this phylum are ubiquitous in the environment. Genomic information suggests that A. capsulatum may be a key decomposer in soil and aquatic environments because of the number of potentially encoded polysaccharide-degrading enzymes capable of providing simple sugars. However, A. capsulatum may not be able to metabolize glucose and other sugars directly through the glycolytic or Entner-Dourdoroff pathways because no F1, 6BP aldolase, or KDPG dehydratase genes were identified in the genome. A. capsulatum does have a transaldolase and most of the genes for the pentose phosphate shunt (PPS) suggesting that these organisms use PPS to distribute carbon between biomass production, energy generation, and polysaccharide synthesis. To test this hypothesis, A. capsulatum growth under aerobic conditions in a minimal media with glucose as the sole carbon source was characterized. Free glucose was found to be completely consumed after about 90 hours at ambient temperature and distributed about 40% in biomass, 40% consumed for energy, and 20% used for polysaccharide synthesis. Aqueous cell lysates of A. capsulatum quenched with perchloric acid at thetop of exponential were shown by 1H-NMR to be rich in ribonucleotides, sugars, alcohols, and precursors to membrane components. However, from these results we could not conclude that the PPS is the central metabolic pathway for the catabolism of glucose. Future studies will use 13C-labeled glucose, 13C-NMR, and LC-MS to better determine the glucose metabolites under these conditions.

: Nutritional Factors Comparing Predisposition to the Development of Insulin-Resistance in Native Americans & Caucasian College Students; It is known that Native Americans are more likely to develop diabetes when compared to Caucasians. What is not known is why. This study compares the differences in diet, and lifestyle between Native American and Caucasian students at Fort Lewis College in order to determine the variables responsible for the differences in prevalence of diabetes between the two races. BMI was used to match Native American subjects to Caucasian subjects. Subjects had height, weight, %body fat and waist-to-hip measurements taken, and filled out a nutritional questionnaire. Differences between Native Americans and Caucasians when comparing % body fat, waist-to hip rations, carbohydrate, protein and fat intake, and exercise were analyzed. We found that Native Americans (NA) consumed significantly more carbohydrates (mean (NA)=54.97% + 7.87 vs. mean (CA)= 44.45% + 9.19; p=0.007), which corresponded to a higher percent body fat (mean (NA)=20.90% + 5.77 vs. mean (CA)=18.65% + 5.18; p= 0.05) and higher waist to hip ratios (mean (NA)= 0.82 + 0.08 vs. mean (CA) 0.80+ 0.065; p=0.059). Since previous studies had shown the link between inflammation and diabetes we believe that Native Americans may be more prone to developing diabetes because of a high carbohydrate diet leading to increased body fat specifically in the abdominal region, which is linked to increased inflammation in the body and the subsequent development of insulin resistance.

Main menu

Pages

Pages

Main menu

You are here

User login

STRATA

Pages

Pages