Biology Commons^™

Tracing Deuterium Through The Food Web And Into Birds And Mammals Along An Elevational Gradient In The Southern Rocky Mountains, Matthew J. Baumann

Biology ETDs

Animals incorporate local δ2H values from available water and dietary sources during tissue synthesis, which can provide evidence of elevational movements if multiple tissues with different turnover times are examined. Here we test the applicability of using δ2H as an indicator of altitudinal movements by examining multiple tissues (δ2Hbw (body water), δ2Hfeather, δ2Hfur, and δ2Hclaw) in birds and mammals in the Sangre de Cristo Mountains. Additionally, we measured δ2Hsw (stem water) and insect δ2bw and δ2wb (whole body) values to assess changes with elevation. We sampled 15 species of birds and two small mammal species along with potential food sources …

Dispersal, Facilitation, And Burrow Architecture In Banner-Tailed Kangaroo Rats, Andrew J. Edelman

Biology ETDs

The largest and most dominant kangaroo rat species in the Chihuahuan Desert is the banner-tailed kangaroo rat (Dipodomys spectabilis). This keystone species constructs mounds containing a complex burrow system around which their ecosystem engineering activities are centered. I studied a population of banner-tailed kangaroo rats at the Sevilleta National Wildlife Refuge, New Mexico from 2005-2009. Specifically, I examined how banner-tailed kangaroo rats: 1) modify their mounds in response to seasonal conditions; 2) spatially affect harvester ants (Pogonomyrmex rugosus) through ecosystem engineering activities; and 3) differ in timing of natal dispersal between sexes. I used mark-recapture, genetic, experimental, and spatially-explicit methods …

Respiratory Physiology During Gravidity In Crotaphytus Collaris And Gambelia Wislizenii, Casey Anderson Gilman

Biology ETDs

During gravidity lizards experience a significant decrease in lung volume as a result of compression by growing eggs within the body cavity. In order to understand the effect of this decrease in lung volume on respiratory physiology of gravid egg-laying lizards I measured changes in: total lung volume, resting and post-exercise expired volume, minute volume, respiratory frequency, and carbon dioxide production during reproduction in Crotaphytus collaris and Gambelia wislizenii. I found that compression of the lungs by eggs resulted in an average 48% (range: 26 to 70%) decrease in total lung volume in C. collaris, and an average 38% (range: …

Molecular Phylogenetic Investigation Of Microbial Diversity And Nitrogen Cycling In Lava Tubes, Jennifer Jane Marshall Hathaway

Biology ETDs

Worldwide, lava tubes host colorful microbial mats on their walls and ceilings. Little is known about the diversity and ecological roles of the bacteria communities in the subsurface ecosystem of lava tubes. White and yellow microbial mats were collected from four lava tubes from the Azorean island of Terceira and from four lava tubes on the Big Island of Hawaii, to compare and contrast the diversity of bacteria found in lava tubes. The 16S rRNA gene was sequenced in order to determine the diversity within these caves, and to begin to elucidate the environmental controls on microbial diversity in the …

The Role Of Spatial And Genetic Modeling To Biogeography, Dolly Lyne Crawford

Biology ETDs

One of the most persistent challenges in biology is explaining the distribution of animal taxa. Quantitative explanations for the distribution of organisms are challenged by the complexity of factors that potentially limit a species range, including topography, ecology, climate and biology. Because of limits on data and approaches, early biogeographers were hampered in their ability to explain patterns. Here, I benefit from two primary developments in biogeography. My research draws from the accumulation of data across several scientific disciplines and advances in spatial and statistical approaches to examine the distribution of animal taxa within an integrative biogeography framework. I combine …

The Physiological Ecology And Evolution Of Freezing Tolerance In Diploid Larrea Sp., Juliana Sibylla Medeiros

Biology ETDs

A basic understanding of vegetation responses to temperature and precipitation variability is paramount to the understanding of ecological adaptation, and comparisons across warm deserts are needed to increase our understanding of the controls on establishment in warm desert ecosystems. At the high latitude edges of warm deserts drought and freezing lower plant performance due to xylem dysfunction, as freeze-thaw embolism reduces stomatal conductance, or damage to leaf photosynthetic apparatus, as tissue desiccation reduces photosynthetic efficiency. Variation in these physiological responses can be observed across life-history stages, genetic background, climate gradients, and species, and this variation may be acted on by …

The Effect Of Plant Source Location On Restoration Success: A Reciprocal Transplant Experiment With Winterfat (Krascheninnikovia Lanata), Melanie G. Barnes

Biology ETDs

It is increasingly important that plant propagules used in revegetation projects are from a location that is geographically or ecologically similar to the planting site. To better understand the consequences of using non-local plant materials, I chose to study the population biology of the widespread shrub winterfat (Krascheninnikovia lanata, Chenopodiaceae) among five populations in New Mexico, USA. Winterfat plant morphology among the five populations was compared, and the rate of emergence and floral onset was measured in a greenhouse common garden. A reciprocal transplant experiment was planted in which individuals from different locations were planted in replicate common gardens. Transplant …

Statistical Methods In Microarrays And High-Throughput Flow Cytometry, Osorio Meirelles

Biology ETDs

Abstract-I

Background: Heterogeneous cell populations have previously been described as noisy. However, recent studies have demonstrated that heterogeneity can be biologically significant. We present here an approach for rapid and complete identification of heterogeneous cell populations from high-throughput flow cytometry data. We have developed a novel measure Slope Differentiation Identification (SDI) using flow cytometry-based protein expression, quantifying the rate of change in protein expression between two conditions (exponential and stationary phase) of yeast cells, as a function of cell size or cell granularity.

Results: SDI had superior Gene Ontology enrichment when compared with other approaches such as k-means clustering and …

Environmental Regulation Of Carbon Isotope Discrimination And Internal Co2 Conductance In C3 Leaves, Christopher Paul Bickford

Biology ETDs

Stable carbon isotopes are powerful tools for elucidating leaf- and ecosystem- level processes, and recent technological developments provide new opportunities to assess the isotopic flux during leaf gas exchange. In these studies I used a tunable diode laser spectroscope coupled to a infra-red gas analyzer to measure the isotopic composition of leaf gas exchange at high frequency in both field and greenhouse settings and assess environmental regulation of carbon isotope discrimination (Δ) and internal conductance of CO2 to sites of carboxylation (gi). I measured Δ and gi across diurnal and seasonal periods in field-grown Juniperus monosperma trees and used these …

Description Of Thermonectus Nigrofasciatus And Rhantus Binotatus (Coleoptera:-Dytiscidae) Mating Behavior, Lauren M. Cleavall

Biology ETDs

Models of sexual conflict predict that diving beetles should respond morphologically and behaviorally during mating events to overcome the opposing sex. Morphological and behavioral adaptations may result from pressures by one sex to overcome resistance to mating attempts of the opposite sex. Morphological data supports an evolutionary arms race in diving beetles (Dytiscidae) exhibited in a series of adaptations attributable to sexual conflict between males and females. Males of certain Dytiscinae have sucker shaped adhesion setae on their front and mid tarsi to improve attachment to the females elytra prior to and during mating, whereas females have evolved grooves, ridges, …

Transient De-Coupling Of Photosynthesis And Stomatal Conductance In Response To Leaf Primary Vein Cut In Helianthus Annuus, Laura Elizabeth Green

Biology ETDs

Control of stomatal aperture is the primary way plants regulate gas exchange in the short-term, but what triggers stomatal responses to water stress is still debated. Chlorophyll-a fluorescence imaging, local leaf temperature, and gas exchange were measured simultaneously following a cut to primary leaf vein of Helianthus annuus to access the effect of local leaf xylem cavitation on leaf function. The treatment was repeated under 3 different vapor pressure deficit (VPD) conditions. Surprisingly, photosynthesis (A) and stomatal conductance (gs) responded inversely immediately following the treatment, indicating that A was not CO2 limited by stomatal closure. Comparisons of fluorescence images and …

Taxonomic Revision And Phylogenetic Analysis Of The Genus Elytroleptus (Dugés) (Coleoptera: Cerambycidae: Cerambycinae: Trachyderini), Traci Lee Grzymala

Biology ETDs

The longhorned beetle genus Elytroleptus (Dugés) (Cerambycidae:Cerambycinae: Trachyderini) is revised to include fifteen species. One new species is described: E. quadricostatus sp.n. (Grzymala & Miller). Three new synonymies are proposed: E. dichromaticus (Linsley, 1961) = E. divisus (LeConte, 1884) syn. n.; E. luteicollis (Skiles & Chemsak, 1982) = E. ignitus (LeConte, 1884) syn. n.; E. peninsularis (Hovore, 1988) = E. immaculipennis (Knull, 1935) syn. n. The genus is generally distributed throughout the southwestern United States, Mexico, and Central America (Guatemala, Honduras, and Nicaragua) with one species extending the range to the north and southeastern United States. The genus is of …

The Effects Of Stream Discharge And Channelization On The Macroinvertebrate Community In A Semi-Arid Landscape, Thomas L. Kennedy

Biology ETDs

The Middle Rio Grande is the second largest watershed in the southwestern United States and is a vitally important component for the biodiversity in the region. Similar to many other rivers, the MRG is a temporally dynamic system that unfortunately, has been subjected to river regulation. As a result, the river has become channelised in many reaches disconnecting it from the surrounding floodplain. The effects of river regulation on the MRG and its surrounding riparian zone were largely unknown. I tested three main hypothesis with regards to the macroinvertebrates in the MRG: 1) Does flow variability structure the aquatic macroinvertebrate …

Controls On Microbial Community Structure In Thermal Environments: Exploring Bacterial Diversity And The Relative Influence Of Geochemistry And Geography, Kendra Renee Mitchell

Biology ETDs

Community wide molecular surveys have revealed incredible hidden phylogenetic and metabolic diversity in microbial habitats. We have conducted the first microbial survey of Yellowstone National Park thermal environments, sampling 103 communities from across the park and across the range of conditions found. Yellowstone is particularly suited for this type of research because of the large number and wide variety of thermal springs, which are naturally occurring chemostats enabling examination of the factors that control microbes and drive community structure. In addition to samples for molecular microbial analysis, we collected water for extensive geochemical analysis in order to begin to deduce …

Current And Historical Aquatic Food Webs Of The Middle Rio Grande, Nm, Melanie S. Edwards

Biology ETDs

The Rio Grande has been identified as one of the most endangered rivers in the United States by American Rivers. Biologically, the consequences of the massive anthropogenic alterations of this river have been substantial. The overall aim of this study was to characterize the ecological implications of these alterations in the aquatic food web of the middle Rio Grande (MRG) of New Mexico. Our approach was to analyze the stable isotope composition of current food web components and of historical museum preserved fish specimens. After determining that we could use stable isotope analyses of historical museum preserved fish specimens (chapter …

The Galapagos Giant Tortoise (Geochelone Elephantopus) And The Spread Of Invasive Plants, Anne D. Schultz

Biology ETDs

Island ecosystems are commonly thought to be more vulnerable to the effects of invasive species than mainland systems. In recent decades, the number of exotic plants known to be present in the Galapagos archipelago has increased exponentially. Several of these plants are aggressive invaders that pose a threat to the biodiversity of the islands. Two of these plant species, Passiflora edulis Sims and Psidium guajava L. were introduced to Santa Cruz Island during the 20th century. Both pose a threat to the floristic diversity of the National Park land on Santa Cruz Island.

This paper explores the role played by …

Potential Influences Of Biotic And Abiotic Factors On Patterns Of Activity In Galapagos Snakes: Locomotory Performance Or Prey Abundance?, Marco A. Altamirano

Biology ETDs

Biotic and abiotic factors were considered as the potential factors influencing the activity pattern of Galapagos snakes. Three hypothesis are tested in this study in order to examine the causes of variation in snake activity. The first hypothesis (variation in the number of snakes active throughout the day is caused by distribution and abundance of their prey) is rejected because snakes and lizards have different patterns of activity. Moreover, Chi-square Goodness-of-Fit test and 2 x 2 Contingency tables show significant differences between these patterns of activity. However there are hours of the day when lizard activity could influence snake activity. …

Climatic And Geomorphic Controls On Semi-Fluvial Ecosystems, Max Aldon “Tad” Crocker Jr.

Biology ETDs

In most climatic regions, the growth of ecological knowledge for terrestrial and limnological components of landscapes have roughly occurred in tandem. But at a time when the world's deserts are increasingly used for human development, and particularly so along water courses, knowledge of how stream ecosystems function within semi-add landscapes has seriously lagged the productive history of terrestrial research there. How terrestrial and limnological components interact within semi-arid landscapes will elude a useful scientific understanding of semi-arid landscapes and will preclude wise landscape management policies as long as semi-arid fluvial ecosystems in general, and ephemeral streams in particular, remain poorly …

Community Structure Of The Arthropods Of Carlsbad Cavern Emphasizing Raphidophoridae Of The Genus Ceuthophilus, Diana Northup

Biology ETDs

Censusing of cave arthropods has been carried out in three areas of Carlsbad Cavern from 1984 to 1987, using pitfall traps. The areas represent a food rich area (Bat Cave, a guano community with high species richness), a food poor area (Sand Passage, an area deep within the cave, with low species richness), and an area with moderate food resources (Left Hand Tunnel, an area near the Underground Lunch Room). Species diversity, as estimated by Hill's N₂, showed that Left Hand Tunnel had values closer to one ( dominance by one species), while Sand Passage and Bat Cave …

The Behavioral Ecology Of The Cooperatively Breeding Harris' Hawk In Southeastern New Mexico, James Cary Bednarz

Biology ETDs

I describe the breeding pattern and system of the Harris' Hawk (Perebuteo unicinctus) and test several hypotheses that have been proposed to explain avian cooperative breeding systems. Individual Harris' Hawks were color-marked and monitored for a 40-month period in southeastern New Mexico. Between 29% and 70% of Harris' Hawk social units made a second breeding attempt in either late summer or autumn within each year, often following successful spring breeding. Clutches were initiated between 17 February and 1 November. The interbrood period was positively correlated with the size of the first brood. The number of second nests initiated was correlated …

Biochemical Variation Of The Desert Tortoise, Gopherus Agassizi, Randy Dean Jennings

Biology ETDs

Relationships among populations of the desert tortoise, Gopherus agassizi, were assessed using starch-gel electrophoresis. Concurrently, tortoises obtained for the electrophoretic study were used in a preliminary morphological analysis. Morphologically, males differed from females in the gular shape and anal scutes, front foot width, carapacial doming, and the posterior curvature of the carapace. Only anal notch depth differed among habitats for female tortoises, while differences in gular length, front foot width, anal notch depth and width, and carapacial flatness were detected among males. Differences in foot and gular shape may reflect their importance in male:male agonistic encounters. Shell shape differences between …

Hybridization In Black-Capped (Parus Atricapillus) And Mountain (P. Gambeli) Chickadees In The Middle Rio Grande Valley Of New Mexico, William Harkness Howe

Biology ETDs

Hybridization between black-capped and mountain chickadees was examined in 238 km of riparian woodland along the Rio Grande in central New Mexico. Chickadee densities and distributions were assessed and an attempt made to locate all breeding pairs of chickadees in the 25 km where hybridization was most common. Members of each pair were identified, vegetational aspects of nest sites and territories measured, and breeding success of the different pair combinations monitored when possible.

The hybrid zone probably dates back to the early 1970's, when black-capped chickadees first bred in this portion of the Rio Grande valley. Here, both species are …

Brood Reduction In Chihuahuan Ravens: An Experimental Study, Joe Haydock

Biology ETDs

Hypotheses concerning the adaptive significance of asynchronous hatching in relation to brood reduction were tested using experimental manipulations of brood of Chihuahuan Ravens (Corvus cryptoleucus) in southeastern New Mexico in 1981 and 1982. Additionally, in 1978 and 1979, breeding success was monitored at the study site. Several types of experimental manipulations, including the following, were performed on newly hatched nestlings: (1) The largest nestling in a nest was transferred to another nest were it was approximately equal in weight to the smallest nestling (runt) in that nest. (2) The smallest nestling of a nest was transferred to another nest where …

Comparison Of Electron Microscopy And Immunoelectron Microscopy With The Enzyme-Linked Immunosorbent Assay For The Detection Of Rotavirus And Antibody To The Virus, Maria Del Carmen Monedero

Biology ETDs

Rotavirus has been shown to be an etiological agent of acute gastroenteritis, in human infants and children and in young animals, such as mice, calves, lambs, and pigs. Bovine, porcine, simian (SA-11) rotaviruses and the “0” agent (sheep, goat) have been cultivated in cell cultures. To date the human rotavirus has been propagated only in fetal intestine organ cultures, where it has lost infectivity after a few passages. For this reason, methods of detection of the human rotavirus and serological tests for antibodies to it have been difficult to develop. At the present time there are several techniques that are …

Distribution Of Plutonium In Beagle Dog Liver, Jeffery M. Gearhart

Biology ETDs

Plutonium that reaches the systemic circulation by inhalation, ingestion or through cuts or abrasions is preferentially deposited in the liver and bone. Liver cancer may be an important late effect of this deposition. This study was designed to provide improved quantita­tion of the distribution of plutonium deposited in liver as a result of gradual introduction into the blood by absorption from the lung, com­pared with the immediate introduction by intravenous injection of a soluble form. In this study, Beagle dogs were exposed to an aerosol of ²⁸⁰Pu0₂ or an intravenous injection of ²³⁸Pu or ²³⁹Pu-citrate. Animals …

The Effect Of Corticosteroid Therapy On Lung Immunity Following Localized Deposition Of Antigen In Lungs Of Beagle Dogs, Dorothy Victoria Leyva Harris

Biology ETDs

Inhaled toxic materials can interact with lymphoid tissues of the respiratory tract resulting in altered immune responses. To test the effect of immunosuppression on lung immunity, corticosteroids were administered to Beagle dogs systemically or directly into the lung. Specific lung airways were lavaged at 5, 7, 10, and 12 days after intra­pulmonary immunization with sheep red blood cell (SRBC) antigen. The cytology of the bronchoalveolar cells in lung lavages was evaluated, and lymphoid cells isolated from lung airways and from blood were tested by the Cunningham assay for in vitro production of antigen-specific IgM and IgG antibodies. In addition, the …

Respiratory Patterns And Oxygen Uptake In The Garter Snake, Thamnophis Elegans, James Whitney Hicks

Biology ETDs

Eight garter snakes, Thamnophis elegans, were collected in northern New Mexico during July and August. The snakes were kept in an environmental chamber and were entrained to a 141 (0630-2030 h) / 10D (2030-0630 h) cycle for five weeks at 25 C. Ventilation was monitored with a head/body plethysmograph. Pulmonary oxygen uptake was measured by open-system respirometry. Heart rate was recorded with electrodes implanted subcutaneously, bi-lateral to the heart. Ventilation, oxygen uptake and heart rate were measured simultaneously at 25+-1 C. All measurements were recorded continuously for 48-96 hours. As well as investigating the diurnal rhythms of ventilation, oxygen uptake …

Lectin Stimulated Human Neutrophil Migration And Cap Formation, Cynthia J. Kuehn

Biology ETDs

Neutrophils have been described as the secretory organ of the inflammatory response (1) and are the main effector cells in host defense against acute bacterial infection (2,3,4,5). However, the mechanism by which cells move directionally toward or away from an inflammatory focus is a biological phenomenon which is poorly understood. Chemotaxis, directional migration, has been defined as a change in the direction of locomotion of a cell or organism, initiated by substances in the environment (6). Chemokinesis, on the other hand, is a change in speed or frequency of turning in randomly moving cells, induced by substances in the environment …

Effects Of Barbiturates On Postsynaptic Responses In Aplysia Californica, Ila Leigh Cote

Biology ETDs

Barbiturates are widely used drugs, both as anticonvul­sants and anesthetics. However, their mechanisms of action are presently unclear although a number of hypotheses have been proposed to explain their effects. These hypotheses have primarily viewed the synapse as the site of barbiturate action.

The aim of this study was to elucidate some cellular mechanisms of action of the barbiturates and to suggest some correlations to their clinical properties. The effects of sodium phenobarbital and sodium pentobarbital on responses to iontophoretically applied neurotransmitters, primarily acetylcholine and gamma aminobutyric acid, were studied. The use of voltage clamp techniques in single neurons of …

Host Plant Preference In Two Generalist Herbivores, Jody Genelle Gray

Biology ETDs

The host plant preferences of two generalist lepidopteran herbivores were investigated at a field site near Albuquerque from 1977 to 1979. Observations of larvae in the field and measurements of available biomass for each host plant were combined to calculate preference rankings for host plants. Similarly, the relative preference of each herbivore for young or mature leaves was calculated. Both Estigmene acrea (Drury) and Hyles lineata (Fabricius) preferred to feed on Rumex hymenosepalus in the spring. H. lineata is univoltine and was not observed feeding on any other plant species. E. acrea is bivoltine and feeds on Senecio longilobus, Helianthus …