Life Sciences Commons^™

Assessment Of Vegetation Response To Wildfire At Bandelier National Monument, New Mexico: Case Study Of The Las Conchas Fire, Gladys Valentin-Gonzalez

Geography ETDs

In the past couple of decades, there has been an increase in the occurrence of wildfire events in the United States. The U.S. Forest Service estimates that over 73,000 wildfires on average occur annually in the U.S., burning about 7.3 million acres of land. Bandelier National Monument, in northern New Mexico, has been affected by several wildfires in the past 40 years, one of the most recent being the Las Conchas Fire in 2011, which burned over 60,700 hectaresin Bandelier National Monument and Valles Caldera National Preserve. This research explores a remote-sensing based assessment of vegetation response to and recovery …

Omega-3 Polyunsaturated Fatty Acids: Impact On Oxidative Stress, Antioxidant Responses And Vascular Function, Kayla R. Zehr

Biomedical Sciences ETDs

Cardiovascular disease (CVD) is the leading global cause of death, and cigarette smoking (CS) is a major risk factor for CVD. Although there are smoking cessation programs that include a combination of pharmacological and behavior treatments, failure to curb behavioral habits and pharmacological addiction leads to low cessation success rates. Thus, developing a treatment to decrease CVD risk is critical. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) decrease oxidative stress and have been shown to restore endothelial function, an indicator of CV health, in cigarette smokers. Metabolites of n-3 PUFAs have been shown to have CV-protective effects, but the mechanism by …

Cholesterol Regulation Of Pulmonary Endothelial Calcium Entry Following Chronic Hypoxia, Bojun Zhang

Biomedical Sciences ETDs

Chronic hypoxia (CH)-induced pulmonary hypertension (PH) is associated with diminished ATP-induced endothelial Ca2+ entry as well as membrane cholesterol in pulmonary arteries. Store-operated Ca2+ entry (SOCE) and depolarization-induced Ca2+ entry are major components of the response to ATP and are similarly decreased after CH. Because endothelium-dependent vasodilation is closely associated with pulmonary endothelial [Ca2+]i, the blunted agonist-induced Ca2+ influx in pulmonary artery endothelial cells (PAEC) may contribute to the development of CH-induced PH. Interestingly, impaired agonist-induced Ca2+ influx in PAEC following CH can be restored by membrane cholesterol supplementation. In the current studies, we hypothesized that impaired Ca2+ entry in …

Comparison Of Bacterial And Archaeal Communities In The Subsurface Versus Surface: Implications For Nitrogen Cycling, Jason C. Kimble 5059801155

Biology ETDs

Arid-land caves are thought to be extremely nitrogen-limited, but almost nothing is known about how microbes in subsurface arid-land environments obtain this essential element to meet cellular demand. The depth of caves beneath the surface may represent a critical factor affecting microbial nitrogen cycling in these environments. Percolation of water and nutrients from a precipitation pulse event would affect deep arid-land carbonate caves at a much slower rate. To obtain nitrogen in deep, carbonate caves, microorganisms could use fixed N in the host rock for assimilatory biochemical pathways or for a respiratory electron acceptor. However, the latter process leads to …

Forage Selection And Habitat Architecture As Drivers Of Small Mammal Community Dynamics In An Arid, Nutrient Limited, Highly Stochastic Ecosystem, Jennifer Darby Noble

Biology ETDs

In the Northern Chihuahuan desert, grassland and shrubland co-occur as separate stable states under similar climatic conditions. In this bottom up (resource driven) system, the magnitude and timing of precipitation events drives primary production which varies from year to year and season to season. Climate change is predicted to alter precipitation regimes, and increase aridity, facilitating shrub encroachment which results in increased landscape heterogeneity and a decrease in plant biodiversity. These changes will likely result in a restructuring of small mammal communities.

We used long-term data on precipitation, primary production, and abundances of small mammals in adjacent grassland and shrubland …

Diatom Community Response To An Acidic, Ambient Temperature, Geothermal Gradient, April Fox

Water Resources Professional Project Reports

Geothermally influenced surface waters are typically linked to high temperatures; however, they can also be associated with ambient temperature and have the distinct solute chemistry that identifies them as geothermal in origin. Few studies have been linked to diatom assemblages in ambient temperature, geothermally influenced waters. This study focused on the Sulphur Creek watershed in the Valles Caldera National Preserve, northern New Mexico. Seven representative sites were sampled monthly between May 2016-September 2016 for physicochemical parameters and diatom community composition. Ambient temperature waters with high conductivities, lower pH values (≤ 4.0), and increased Al+++, Fe++, SO4=, and SiO2 concentrations are …

Bacterial Siderophore Production In Lechuguilla And Spider Caves, Carlsbad National Park (Ccnp) Carlsbad, New Mexico, Tammi R. Duncan

Biology ETDs

Lechuguilla and Spider caves, Carlsbad Caverns National Park, contain a rich microbial diversity. Despite oligotrophic conditions, the microorganisms in these caves have developed strategies to acquire essential nutrients. I hypothesized that cave bacteria use siderophores, a ferric iron chelating compound, to acquire iron for essential life processes. To understand the backdrop against which the cave bacteria would produce siderophores, I examined the bacterial physiological characteristics, determined whether cave bacteria have an ability to produce siderophores, and investigated a possible correlation between iron and manganese concentrations in cave deposits and siderophore production by bacteria cultured from the same site. I carried …

Investigation Of Physical And Chemical Characteristics Of Soils From High, Moderate, Low And Unburned Severity Areas Following The 2011 Las Conchas Fire, Amanda A. Otieno

Water Resources Professional Project Reports

Soils play an essential role in ecosystem health as they are the medium for terrestrial and aquatic life. Soils can be drastically altered by wildfire as seen in the Jemez River watershed following the 2011 Las Conchas fire which burned over 31,800 acres. The aim of this research is twofold: 1) to characterize the effects of fire on the cation and anion composition in soil by burn severity following the 2011 Las Conchas wildfire and 2) to assess the leaching capacity of nitrate (NO₃^-), phosphate (PO₄^3-)_, sulfate ₍SO₄^2-), aluminum …

Diatom Communities Of Travertine-Precipitating Springs On A Gradient Of Anthropogenic Disturbance In The Sandia Mountains, New Mexico, Kathryn E. Mendoza

Water Resources Professional Project Reports

Carbonate-rich waters of travertine-precipitating springs facilitate unique physiochemical environments that support distinct diatom species assemblages adapted to the environmental stress of constant carbonate precipitation. Diatom communities in spring systems may be further limited by the impacts of historical and ongoing anthropogenic disturbance, which includes recreational activity and hydrologic modification of springs using spring boxes and wells. This study focused on impacts of water chemistry and anthropogenic disturbance on diatom assemblages found in travertine-precipitating springs. Data were collected in the fall of 2016 and spring of 2017 at eight spring sites, including six known to precipitate travertine, in the Sandia Mountains …

Exploring Biological Heterogeneity And Its Consequences At Tissue And Cellular Scales Through Mathematical And Computational Modeling, Romica Kerketta

Biomedical Sciences ETDs

This dissertation explores the effects of heterogeneity across different biological scales in cancer as well as normal cells. At the tissue scale, we investigated the variability present in the tumor microenvironment and its effect on patient chemotherapeutic outcomes using a mathematical model of drug transport. We found that parameters such as tumor blood perfusion and radius of blood vessel had an impact on the tumor cytotoxicity. This indicated that the physical microenvironment of the tumor is an important regulator of the tumor response to chemotherapy. At the cellular scale, we investigated the heterogeneity present on the membrane landscape of ErbB2 …

Dynamics Of Community Composition And Ecological Processes In Mesic And Semiarid Grasslands, Sydney K. Jones

Biology ETDs

Grassland communities change in response to disturbance and chronic resource alterations. Temporal community dynamics were examined within mesic tallgrass prairie at Konza Prairie in northeastern Kansas, and semiarid desert grassland and shrubland in central New Mexico. In both grasslands, producer and consumer communities changed over time in response to fire frequency and shrub encroachment. Directional change was driven by changes in abundances of species already in the community, rather than turnover in species composition. Despite directional change, species richness was highly stable, making species abundance rather than richness a better indicator of future community change. Species reordering also occurred during …

The Impact Of Climate And Elevation On The Growth And Mortality Of Piñon Pine, Alice M. Fretz

Biology ETDs

The Southwestern United States is currently experiencing severe drought, resulting in the mortality of many tree species. Piñon-juniper woodlands are an extensive biome in the Southwest, and are highly vulnerable to extended periods of drought that lead to tree mortality. Specifically, Pinus edulis populations are decreasing due to increasingly arid conditions. I used dendrochronology to investigate how tree growth rings of Pinus edulis reflect severe drought in living and dead trees. I also investigated how severe drought affects Pinus edulis along an altitudinal gradient. Tree core samples were taken from currently living and dead trees, as well as from trees …

Nutrient Additions Alter Semi-Arid Grassland Response To Fire, Alec A. Carrigy

Biology ETDs

Knowledge of how multiple global change drivers interact to affect community structure is critical for predicting future community states, especially when community structure drives ecosystem function. Disturbances such as fire and nutrient additions often shift communities away from their mean composition, but less is known about how disturbances affect spatial variation among local patches of the community over time (spatiotemporal dispersion). Dispersion may increase (local communities diverge in composition), stay the same, or decrease (communities converge) in response to disturbance. We compared patterns of spatiotemporal dispersion and temporal trajectories in community composition across three sites in a northern Chihuahuan Desert …

Diet Specialization Does Not Explain Occupancy Or Abundance In A Test Of The Resource Breadth Hypothesis In A Small Mammal Community, Deborah R. Boro

Biology ETDs

The abundance-occupancy relationship (AOR) is a recurrent pattern in ecology and biogeography, in which species with expansive distributions are locally common while those with restricted distributions are locally rare. Despite occurring across a wide variety of taxa and spatial scales, the mechanisms underlying AORs are not well understood. I tested two such mechanisms regarding dietary generalism in a guild of 8 small, herbivorous African mammals: (1) the degree to which diet was explained by food availability, and (2) population-level diet breadth. I expected that food availability would better predict diet for abundant, widespread species than rare, restricted species. Additionally, I …

Genetic Approaches To Population Ecology And Conservation Of The Sacramento Mountain Salamander, Samantha Jo Nicole Cordova

Biology ETDs

Aneides hardii (Sacramento Mountain salamander) is restricted to high-elevation habitat that is fragmented by low-elevation piñon-juniper woodland. Aneides hardii is a species of conservation concern in New Mexico, in part, because disease and climate change endanger its long-term persistence. In this study, we use sequence data from the mitochondrial cytochrome b gene and a microsatellite locus of A. hardii to addresses the timing and scale of population subdivision. We also calculated genetic diversity measures and compared them among mountain ranges to explore demographic history of A. hardii. Twenty-six haplotypes and three genetically distinct lineages were identified, and each haplotype …

Dengue Vaccination Modulates The Dengue-Zika Viral System Via Immunogenic Cross-Talk, Noah J. B. Silva

Biology ETDs

A vaccine for dengue, a viral disease which is a major driver of morbidity and mortality in tropical and subtropical regions, has recently been approved by eleven countries. While vaccination has the potential to reduce disease burden, the approved vaccine faces challenges due to the interactions between the four serotypes of dengue virus (DENV1-4) and the potential interactions with Zika virus (ZIKV), a related flavivirus. In this study, we propose a mathematical model incorporating both DENV and ZIKV in order to investigate the effects of viral competition on dengue vaccine performance, the potential for change in incidence of Zika due …

Evaluating The Relationship Of Temperature And Growth Of A Larval Colorado River Catostomid, C. Latipinnis, Through Otolith Aging And Stable Isotopes (Δ18o), Adam Lawrence Barkalow

Biology ETDs

Knowledge of early life history strategies and ecological dynamics of larval fish growth and development is invaluable for effectively managing and conserving common and endangered fish species. Isotopic analysis of otoliths (bony structures of the inner ear) from larval Flannelmouth Suckers Catostomus latipinnis obtained from the Colorado River in Grand Canyon could greatly facilitate understanding of thermally-regulated growth rates, thermal preferences, and ontogenetic habitat use by these fishes. Colorado River water temperatures in the Grand Canyon are highly modified from projected historic water temperatures present before closure Glen Canyon Dam. Cold water as result of Glen Canyon dam and hypolimnetic …

An Integrated Bioinformatic/Experimental Approach For Discovering Novel Type Ii Polyketides Encoded In Actinobacterial Genomes, Wubin Gao

Chemistry and Chemical Biology ETDs

Discovery of new natural products (NPs) is critical both for diseases treatment and crops protection. Numerous NP biosynthetic gene clusters (BGCs) in sequenced microbial genomes allow identification of new NPs through genome mining. Developing an integrated bioinformatic/experimental approach for discovering novel type II polyketides (PK-IIs) facilitates investigation of this family of NPs in an efficient, systematic way. Here, we developed an approach to analyze ketosynthase α/β (KSα/β) gene sequences to predict PK-II core structures, allowing us to target novel PK-II BGCs either from isolated genomic DNA or genomes from the NCBI databank, and to isolate novel PK-IIs produced by these …

A Multiscale Modeling Study Of The Mammary Gland, Joseph D. Butner

Biomedical Engineering ETDs

Multiscale, hybrid computer modeling has emerged as a valuable tool in the fields of computational systems biology and mathematical oncology. In this work, we present an overview of the motivations for, and development and implementation of, three hybrid multiscale models of the mammary gland system and early stage ductal carcinoma in situ (DCIS) in the gland. Pubertal mammary gland development was described first using a two-dimensional, lattice-based hybrid agent-based model description of the mammary terminal end bud (TEB), and then with a three-dimensional lattice-free TEB model. Both models implement a discrete, agent-based description of the cell scale, and a continuum, …

Phylogeography And Population Dynamics Of North American Wolverines (Gulo Gulo Luscus) In Alaska And Western Canada, Dianna Krejsa

Biology ETDs

The circumboreal wolverine (Gulo gulo sp.) is ideal for studying responses to environmental perturbation in the North due to a history of persistence in glacial refugia and subsequent glacial recolonization. Wolverines are also excellent indicators of human influence on the environment due to their close association with remote areas and cold, snowy climes. Through the use of genetic tools (i.e., nuclear microsatellite loci and mitochondrial sequences), I examined population structure of wolverines in Alaska and western Canada to identify signatures of glacial refugia, bottlenecks, and distinctive populations, sex-biased dispersal, gene flow, and source and sink population dynamics. I identified genetic …

The Ecology Of Acequias In The Mora Valley: Patterns, Processes And Place-Based Knowledge, Shannon M. Rupert

Biology ETDs

In northern New Mexico, early settlements were clustered for protection of the people and access to water for domestic and agricultural uses was critical to their success. Irrigation ditches, known as acequias, brought water to the people, and were central to community life. These earthen ditches of varying lengths were built between one hundred and several hundred years ago, and most are still operational today. They divert water away from natural streams and across the landscape, through a system of man-made channels, until the unused water is diverted back into natural watercourses. These lateral channels appear to function as extensions …

Middle Rio Grande Surface And Well Water Quality And The Health Implications To Humans, Juan Carlos Peña-Philippides

Water Resources Professional Project Reports

This professional project reviews the water quality along The Middle Rio Grande in New Mexico from the Cochiti Dam to the town of Bernalillo to San Acacia. This project focuses on the quality of the surface and well water and its implications to human health. The State of New Mexico Environment Department provided historical data of the well water quality in Albuquerque and the surrounding area. This project focuses on the analysis of chemical and microbiological testing in the areas of the North Valley, South Valley and Albuquerque Acres. The Bosque Ecosystem Monitoring Program (BMEP) provided historical data that identifies …

Cortico-Striatal Coordination Disrupted In Behaviorally Inflexible Moderate Prenatal Alcohol Exposed Mice, Kristin L. Marquardt

Biomedical Sciences ETDs

Up to 61% of adolescent school aged children with fetal alcohol spectrum disorder (FASD) have been suspended or expelled. Executive function deficits, like dis-inhibition and cognitive inflexibility, have been proposed to be better predictors of behavioral problems then IQ score, which qualifies these individuals for developmental disability and special school programs. Reversal learning, a widely used behavioral paradigm for assessing cognitive flexibility across species, has been shown to be impaired in rodent models of prenatal alcohol exposure (PAE). Here we show that a mouse model with daily maternal drinking, resulting in a BAC of 85 mg/dl throughout gestation, results in …

Final Report: Status Of The Arizona Toad (Anaxyrus Microscaphus) In New Mexico, Mason J. Ryan, Jacek Tomasz Giermakowski, Ian M. Latella, Howard L. Snell

Biology Faculty & Staff Publications

This report covers the fourth consecutive year (2013-2016) of research on the population dynamics, ecology, and conservation status of the Arizona Toad (Anaxyrus microscaphus) in New Mexico. The year 2016 represented the rare opportunity to study the effects of El Niño, which typically brings above average precipitation to New Mexico, on the breeding behavior and ecology of the Arizona toad. We expected that the El Niño-driven above average precipitation during the winter of 2015 and spring of 2016 would result in increased detection of toads at breeding sites, especially those sites that were dry in 2013, 2014, and …

Natural History And Evolution Of An Elevational Generalist, The Cinereous Conebill (Conirostrum Cinereum), Andrea N. Chavez, Chandresekhar Natarajan, Jay F. Storz, Angela Fago, Christopher C. Witt

Biology ETDs

Elevational generalism is relatively rare in the tropical Andes Mountains, likely owing to the inherent requirements of enduring a high degree of climatic zonation and coping with hypoxic stress. The Cinereous Conebill (Conirostrum cinereum) appears to be an exception, and inhabits a continuous elevational distribution that spans over 4,500 m. Two subspecies, cinereum and fraseri, are restricted to high elevations and may be isolated, whereas the third and most widespread, littorale, occurs continuously along the western slope of the Andes from 0 to over 4,500 m. First, we aim to characterize the morphology, genetics, and climatic …

The Effects Of Atmospheric Pressure On Inter-Specific Competition And The Morphological And Hematological Characteristics Of Elevational Distributions Of Hummingbirds, Ariel M. Gaffney

Biology ETDs

Species diversity in mountainous regions is strongly influenced elevational range limits of species, but it is generally not known which abiotic or biotic factors maintain these limits. Using Black-chinned and Broad-tailed Hummingbirds, species with offset but overlapping elevational ranges in the southwestern USA, we investigate the role barometric pressure plays in influencing these limits. In chapter one, we used a hypobaric chamber to test the effects of variable air pressures on interspecific competitive dominance. We sequenced the genes that encode the two adult isoforms of haemoglobin and measured the O₂-binding affinity of each isoform. In chapter two, we …

Precipitation Patterns And Fungal Community Succession In A Seasonally Dry Secondary Tropical Savanna, Sara R. Lopez

Biology ETDs

Life in seasonally dry areas strongly depends on pulses of precipitation during certain portions of the year. This is particularly relevant for Tropical savannas on the Caribbean coast of Colombia that have been converted from Tropical Dry Forests and subjected to permanent agricultural and grazing practices that in turn induce changes in nutrient status in these systems. Several studies have presented evidence for a shift in C and N dynamics following forest conversion, including a decrease in total soil organic carbon and changes in nitrogen status, but the consequences of forest conversion on soil microbial processes are poorly understood. No …

Immunology Of The Gray Short-Tailed Opossum During Pregnancy And Prenatal Development, Victoria L. Hansen

Biology ETDs

Vertebrate species that bear live young have overcome the evolutionary challenge of maintaining both a functional adaptive immune system and viviparous life cycle. In normal pregnancy, viviparous mothers are able sustain and nourish a fetus that is genetically half non-self without mounting an immunological attack. In 1953 Sir Peter Medawar brought attention to the “enigma of the fetal graft” and immunologists have been puzzling out the intricacies of fetal tolerance ever since. Although viviparity has evolved in all jawed vertebrate lineages aside from Aves, the vast majority of reproductive immunology research has been limited to eutherian mammals. There are insights …

Cd82 Membrane Scaffolding Regulates Hematopoietic Cell Functions, Christina M. Termini

Biomedical Sciences ETDs

Through their ability to self-renew and differentiate, hematopoietic stem/progenitor cells (HSPCs) maintain the adult blood and immune systems. The microenvironment, or niche, in which HSPCs reside, serves as a critical regulator of HSPC functions. As previous work has identified the tetraspanin CD82 as a mediator of HSPC-niche interactions, we aimed to determine the mechanism by which this occurs. Our data demonstrate that CD82 expression and scaffolding regulate HSPC interactions with niche components by organizing the α4 integrin subunit into tightly packed nanoclusters. The HSPC niche can also protect acute myeloid leukemia (AML) cells from therapeutics. Therefore, we next examined how …

Plant-Microbial Interactions Are Strong Determinants Of Plant Population And Community Dynamics, Y. Anny Chung 9485698

Biology ETDs

Plant-microbial interactions are ubiquitous and yet the consequences of these interactions on plant population and community dynamics are relatively unknown. Here, we used two different classes of plant-microbial interactions to examine their effects on key plant population and community characteristics such as commonness and rarity, competition and coexistence, as well as community stability.

Vertically-transmitted endophytes had stage-dependent effects on the population growth of two grass species Poa sylvestris and Poa alsodes, and generally increased host population growth rates. However, it was the intrinsic demographic advantage of P. sylvestris that allowed its population to grow at a much faster rate …