Browsing by Subject "Morphology"
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Item Aspects of phonology and morphology of Teotepec eastern Chatino(2015-05) McIntosh, Justin Daniel; Woodbury, Anthony C.; England, Nora C.; Epps, Patience L; Wechsler, Stephen M; Rasch, Jeffrey W; Suslak, DanielThis dissertation is a description of aspects of the phonetics, phonology and morphology of Teotepec Chatino (ISO 639-3 identifier: cya; here abbreviated as TEO), an indigenous language spoken by approximately 3800 people in the Sierra Madre del Sur, Oaxaca, Mexico. This work presents a synchronic description of the language based on data collected in the eld over the course of six eld trips totaling eighteen months. This investigation is based on a corpus of thirty hours of transcribed and analyzed texts of naturally occurring speech, narratives, data gathered during elicitation sessions, and an expansion of my earlier grammatical sketch (2011). The final result is a description of the phonology and phonetics of tone and some of the morphological processes that exist in the grammar. The focus of this work is to describe the structure of the language produced by native Teotepec speakers and how it is used in an array of contexts. This is reflected in a rich body of procedural texts, conversations, speeches, rants, polemics, prayers, and narratives. These texts are the basis for the description of how the language encodes speakers' knowledge about the world and their greater context. This work arrives at a description of the details of the language while also making broader generalizations about these details. It is not possible that this work cover all aspects of the phonology, phonetics, morphology and so part of the focus has been to capture particular facets of the language and explain them in a way that is detailed while broad enough to be useful to as many as audiences as possible. This includes scholars interested in typology, tone languages, historical linguistics of Otomanguean, linguistic anthropology, anthropology, and the history and culture of the Chatinos, southern Oaxaca and Mesoamerica. The dissertation is written in English; however, I often create grammatical write-ups and practical pedagogical materials for a Spanish literate audience. Materials for TEO have been and will continue to be made available to Spanish and English speakers in order to reach an audience that includes, but is not limited to, members of the community, local and regional educators and literacy efforts, and scholars engaged in the study of Chatino language and linguistics. The approach to this work is data-driven and text-based. It is written in basic descriptive terms, as outlined in Payne (1997); Shopen (2007); Dixon (2010), and Haspelmath (2010). In this way the writing is carried out with fewer aprioristic notions about the language. The goal is to describe the language in its own terms. Thus the researcher is open to discover completely new, unexpected phenomena, can be guided by the data and their own thinking (Haspelmath, 2010).Item Aspects of the phonology and morphology of Zenzontepec Chatino, a Zapotecan language of Oaxaca, Mexico(2014-08) Campbell, Eric William; Woodbury, Anthony C.This dissertation is an analysis of aspects of the phonology and morphology of Zenzontepec Chatino (ISO 639-3: czn), a Zapotecan (Otomanguean) language spoken in a remote area of Oaxaca, Mexico (16°32"N, 97°30"W). There are an estimated 8,000 speakers of the language, but its vitality is weakening due to accelerating shift to Spanish. The phonological analysis begins with the segmental inventory. After that, the autosegmental contrasts are treated, with the highlight being the tone system. The tone bearing unit is the mora, which may bear high tone /H/, mid tone /M/, or no tone Ø. In tone systems with a three-way contrast, the unspecified category is usually the mid-level one. Therefore, Zenzontepec Chatino is typologically unusual in this respect. Special chapters are devoted to phonotactics and phonological processes, including a play language of "speaking backwards" that sheds light on crucial phonological questions, such as the status of glottalization and the limits of prosodic domains. There are also chapters on special topics in phonology: regional variation, Spanish loanwords, and sound symbolism. Another chapter bridges the phonology and the morphology, defining and comparing the phonological word versus the grammatical word, and outlining the basic morphological building blocks: roots, affixes, clitics, and particles. After that, lexeme classes are defined using morphosyntactic criteria, providing a syntactic sketch of the language. The language is strongly head-marking with somewhat agglutinating and synthetic morphology. Another chapter gives an overview of verbal morphology, which is the locus of most of the language's morphology. The dissertation is the beginning of a full descriptive grammar and is part of a larger project to document Zenzontepec Chatino, complementing a dictionary and a documentary text corpus recorded in the community with native speakers. The theoretical approach is one in which the language is explored as much as possible on its own terms using naturalistic textual data supplemented by lexicographic and elicited material. The analysis is not bound by any formal framework, but it is informed by socio-cultural and diachronic considerations. It is situated in a typological perspective to offer more of a contribution to the scientific understanding of the structure of human language.Item Controls on late Neogene deep-water slope channel architecture in a bathymetrically complex seafloor setting : a quantitative study along the Southeastern Caribbean Plate Margin, Columbus Basin, Trinidad(2013-12) Ramlal, Kristie Anuradha; Wood, Lesli J.Slope-channels act as conduits that transport sediments from the shelf staging area to the basin floor. The Pliocene-Pleistocene section of the Columbus Basin in the deep-water slope offshore eastern Trinidad provides an opportunity to study slope-channel morphology and evolution, as well as any association between deep-water deposits, palaeo-seafloor bathymetry, shelf sediment feeder mechanism and changes in sediment supply types and volumes. Approximately 3250 km2 of 3D seismic data allow imaging and interpretation of channels within an interval between two regional surfaces termed P30 and P40. Observations of seismic cross-sections and stratal slices reveal a number of features including channels, mud diapirs, mass transport deposits (MTDs), and faulted anticlinal ridges. Channels appear leveed and unleveed, and alternate with MTDs in a cyclic vertical succession. Nineteen channels were mapped and divided into two groups based on their degree of levee development and stratigraphic position relative to MTDs. Group 1 channels, positioned below MTDs near the base of the interval, are shallowly incised, and show limited levee development. Group 2 channels, situated above MTDs, are relatively deeply incised, and have comparatively larger, well-developed levees throughout their lengths. Morphometric data from these channel groups reveal significant variability in channel width, channel depth, meander belt width, and sinuosity downslope. This variability is associated with influences of temporally equivalent local features and regional sea-floor slope changes. Increased slope gradient causes a marked increase in sinuosity. Diapirs and anticlinal ridges confine channel paths, divert their flow, and cause post-depositional deformation of both levees and channels. Levee height decreases downslope while levee width shows considerable asymmetry, which is related to occurrences of mud diapirism and MTDs. Irregularities on the upper surface of MTDs create accommodation space that confines turbidity flows, enabling ponding of sediments and volumetrically large levee construction. This accounts for dispersion of turbidity flows below the MTD which creates a series of small channels spread over a wide area, and comparatively fewer, confined channels above the MTDs with large levees.Item Diversification of Old World Bats in Malaysia: an evolutionary and phylogeography hypothesis tested through the Genetic Species Concept(2008-05) Anwarali Khan, Faisal Ali; Baker, Robert J.; Wilson, Don E.; Kingston, TiggaObjectives of this study are to use a multifaceted approach to understand biodiversity and systematic implications through the interpretation of genetics and morphological datasets. Extensions to this approach use phylogenetic datasets to infer biogeographic scenarios of diversification, distribution and establishment of monophyletic evolutionary lineage. In Chapter II, I have first assessed the genetic variation within Malaysian bats collected during the TTU-UNIMAS Sowell Expedition in 2006 that are distributed in both Peninsular Malaysia and Borneo. Out of 16 species studied in this study, nine were identified with 5% or more genetic divergences indicating these phylogroups have been evolving independently for sufficient time to speciate by the Bateson-Dobzhansky-Mueller (BDM) model and therefore deserve further study to determine if specific status is merited. Further study on the taxonomy of these species within their geographic range indicates that some of these species merit a specific status. In some cases, they have been recognized previously as subspecies. Using this as the preliminary data, in Chapter III, I have further applied the genetic species concept to the genus: Kerivoula which was found to exhibit more than 10% genetic divergence within morphologically identified species. Based on the field keys available to us we concluded there were at least three species present in our field collection: K. pellucida, K. intermedia, and K. papillosa. However, based on subsequent morphometric and genetic analyses we identified six species within our collection: K. hardwickii, K. intermedia, K. lenis, K. minuta, K. papillosa, and K. pellucida. The utility of multiple data sets to assess poorly studied genera that show morphological similarities is explained.Item The early life history and reproductive biology of Cymothoa excisa, a marine isopod parasitizing Atlantic croaker, (Micropogonias undulatus), along the Texas coast(2012-08) Cook, Colt William; Munguia, Pablo; Buskey, Ed; Walther, BenjaminParasite population dynamics and the evolution of life history characteristics are strongly correlated with the processes of host infection, survival within a host and reproduction, with each process posing a challenge to the parasitic lifestyle. Macroparasites living in marine environments have evolved extreme changes in physiology, morphology and life history traits to overcome these challenges. This study focused on the infective and reproductive stage of the parasitic isopod, Cymothoa excisa, a common parasite on Atlantic croaker, (Micropogonias undulatus), along the Texas coast. A two year survey identified infection rates and the relationship between fish density and size and parasite load, size and fecundity. Isopod morphology was quantified for each life stage, identifying shape transitions through ontogeny and sex change. Sex change in C. excisa was found to be driven by the absence of conspecific parasites within a host, where sex change only occurred in the first individual to arrive. To understand the infective stage of C. excisa parasite energetics and host detection mechanisms were tested. Parasites with free-living life stages have a narrow window to infect a host and have evolved a number of mechanisms to detect and locate a host. I used a series of energetic experiments to determine an infection window for free-swimming larvae (mancae) and behavioral response experiments testing both visual and chemical cues associated with host detection. Mancae were found to have a narrow infection window, where mancae began searching for a host as soon as they are born, but quickly switch to an ambush strategy to conserve energy. Mancae were also found to be responsive to both visual and chemical cues from its common fish host, as well as a non-host fish, indicating that chemical cues are used in host detection, but chemical specificity is not a mechanism that C. excisa uses to find its common host. The results from this study have implications to parasitic species and their hosts, as well as to other areas of study, including population and ecosystem dynamics.Item The effect of temperature and terrace geometry on carbonate precipitation rate in an experimental setting(2012-08) Reid, Ellen Elizabeth; Kim, WonsuckThrough flume experiments we demonstrate the calcite precipitation process seen at geothermal hot springs in the lab setting. A series of four experiments were run, varying temperature and terrace ridge height while all other experimental parameters, including initial substrate slope, spring water discharge, and CO₂ input were kept constant. The goal of the experiments was to measure the temperature and terrace height control quantitatively in terms of the amount of overall travertine aggradation, aggradation rate changes in time and downstream direction, as well as to observe the effect of these parameters on processes occurring during precipitation. Using the final deposit thickness measured manually at the end of each experiment and elevation data obtained from a laser topographic profiler, I conclude that high temperature and small terrace heights favor increased precipitation of travertine. However, the amount of precipitation also depends on location within a terrace pond. Flow velocity increases as it approaches a terrace lip, resulting in enhanced precipitation and greater thicknesses in the downstream direction through increased CO₂ degassing, a process called downstream coarsening.Item Estimating phylogenetic trees from discrete morphological data(2015-05) Wright, April Marie; Hillis, David M., 1958-; Cannatella, David C; Jansen, Robert K; Linder, Craig R; Smith, Martha KMorphological characters have a long history of use in the estimation of phylogenetic trees. Datasets consisting of morphological characters are most often analyzed using the maximum parsimony criterion, which seeks to minimize the amount of character change across a phylogenetic tree. When combined with molecular data, characters are often analyzed using model-based methods, such as maximum likelihood or, more commonly, Bayesian estimation. The efficacy of likelihood and Bayesian methods using a common model for estimating topology from discrete morphological characters, the Mk model, is poorly-explored. In Chapter One, I explore the efficacy of Bayesian estimation of phylogeny, using the Mk model, under conditions that are commonly encountered in paleontological studies. Using simulated data, I describe the relative performances of parsimony and the Mk model under a range of realistic conditions that include common scenarios of missing data and rate heterogeneity. I further examine the use of the Mk model in Chapter Two. Like any model, the Mk model makes a number of assumptions. One is that transition between character states are symmetric (i.e., there is an equal probability of changing from state 0 to state 1 and from state 1 to state 0). Many characters, including alleged Dollo characters and extremely labile characters, may not fit this assumption. I tested methods for relaxing this assumption in a Bayesian context. Using empirical datasets, I performed model fitting to demonstrate cases in which modelling asymmetric transitions among characters is preferred. I used simulated datasets to demonstrate that choosing the best-fit model of transition state symmetry can improve model fit and phylogenetic estimation. In my final chapter, I looked at the use of partitions to model datasets more appropriately. Common in molecular studies, partitioning breaks up the dataset into pieces that evolve according to similar mechanisms. These pieces, called partitions, are then modeled separately. This practice has not been widely adopted in morphological studies. I extended the PartitionFinder software, which is used in molecular studies to score different possible partition schemes to find the one which best models the dataset. I used empirical datasets to demonstrate the effects of partitioning datasets on model likelihoods and on the phylogenetic trees estimated from those datasets.Item Failure mechanics, transport behavior, and morphology of submarine landslides(2010-12) Sawyer, Derek Edward; Flemings, Peter Barry, 1960-; Mohrig, David; Lavier, Luc; Hornbach, Matthew; Shipp, R. Craig; Nikolinakou, MariaSubmarine landslides retrogressively fail from intact material at the headwall and then become fluidized by strain weakening; the final deposits of these flows have low porosity, which controls their character in seismic reflection data. Submarine landslides occur on the open slope and also localized areas including margins of turbidite channel-levee systems. I develop and quantify this model with 3-D seismic reflection data, core and log data from Integrated Ocean Drilling Program Expedition 308 (Ursa Basin, Gulf of Mexico), flume experiments, and numerical modeling. At Ursa, multiple submarine slides over the last 60 ky are preserved as mass transport deposits (MTDs). Retrogression proceeded from an initial slope failure that created an excavated headwall, which reduced the horizontal stress behind the headwall and resulted in normal faults. Fault blocks progressively weakened until the gravitational driving stress imposed by the bed slope exceeded soil strength, which allowed the soil to flow for more than 10 km away from the source area. The resulting MTDs have lower porosity (higher bulk density) relative to non-failed sediments, which ultimately produces high amplitude reflections at the base and top of MTDs. In the laboratory, I made weak (low yield strength) and strong flows (high yield strength) from mixtures of clay, silt, and water. Weak flows generate turbidity currents while moving rapidly away from the source area. They create thin and long deposits with sinuous flow features, and leave behind a relatively smooth and featureless source area. In contrast, strong flows move slowly, do not generate a turbidity current, and create blocky, highly fractured source areas and short, thick depositional lobes. In Pleistocene turbidite channels of the Mississippi Fan, deep-seated rotational failures occurred in the flanking levees. The rotational failures displaced material into the channel from below where it became eroded by turbidity flows. This system achieved a delicate steady state where levee deposition and displacement along the fault into the channel was balanced by erosion rate of turbidity flows. This work enhances our understanding of geohazards and margin evolution by illuminating coupled processes of sedimentation, fluid flow, and deformation on passive continental margins.Item Feedbacks among chemical weathering, rock strength and erosion with implications for the climatic control of bedrock river incision(2016-08) Murphy, Brendan Patrick, Ph. D.; Johnson, Joel P.; Gasparini, Nicole M; Mohrig, David; Breecker, Daniel O; Sklar, Leonard SUnderstanding the processes that erode bedrock rivers and the factors that influence erosion rates is critical to predicting the feedbacks among climate, erosion and tectonics that drive the topographic evolution of unglaciated, active orogens. However, quantitative predictions for the coupling of these feedbacks are limited because the specific mechanisms by which climate controls erosion are poorly understood. Chemical weathering, a climate-dependent process, has been suggested to play a role in the erosion of bedrock rivers, but this idea has largely lacked supporting field or laboratory data. In this dissertation I present field data collected across an orographic precipitation gradient on the Kohala Peninsula of the Big Island of Hawaiʻi. This data demonstrates that the measured rock strength in bedrock river beds is a function of both climate-dependent chemical weathering and abrasional wear. Furthermore, accounting for the effect of chemical weathering on rock erodibility improves the predictions of long-term river profile evolution across Kohala Peninsula. Additional field data was collected and compared to previous experimental data of bedrock erosion in order to explore the feedbacks among chemical weathering, fluvial abrasion and topography at the scale of bed roughness. Finally, inspired by the findings of the field data, I developed a nonlinear dynamical model that finds quantifiable, predictive relationships for changes in rock strength as a function of chemical weathering and fluvial abrasion. The findings in this dissertation demonstrate that the erodibility of bedrock rivers can be influenced by the mechanism of climate-dependent chemical weathering, and that spatial distributions of rock erodibility that develop due to the interactions of chemical weathering and fluvial abrasion can influence the morphology of bedrock rivers from the scale of bed roughness to entire stream profiles.Item Flowers in three dimensions and beyond(2007-12) Thompson, Rebecca Caroline; Marder, Michael P., 1960-Pattern formation in buckled membranes was studied along with the morphology of flowers formed at the tip of silicon nanowires and ripples formed in suspended graphene sheets. Nash's perturbation method was tested for a simple case where initial and final metrics embed smoothly and there is a smooth path from one surface to another and was found to work successfully. The method was tested in more realistic conditions where a smooth path was not known and the method failed. Cylindrical flower-like membranes with a metric of negative Gaussian curvature were simulated in three and four dimensions. These four dimensional flowers had 2 orders of magnitude less energy than their three dimensional counterparts. Simulations were used to show that the addition of a fourth spatial dimension did not relieve all bending energy from the cylindrical membranes. Patterns formed at the tip of silicon nanowires were studied and found to be of the Dense Branching Morphology type. The rate of branching is dependent on the curvature of the gold bubble on which they are grown. Graphene was simulated using the modified embedded atom method potential and buckles were found to form if the carbon bonds were stretched. An energy functional was found for the energy of a sheet with a metric different from that of flat space.Item A grammar of Chol, a Mayan language(2011-08) Vázquez Álvarez, Juan Jesús, 1971-; England, Nora C.; Zavala, Roberto; Epps, Patience L.; Woodbury, Anthony C.; Stuart, David S.This dissertation consists of a description of the grammar of Tila Chol. Chol is one of the 30 Mayan languages spoken in Mexico, Guatemala and Belize. This language is used by nearly 200,000 speakers, distributed in two main dialects: Tila Chol and Tumbalá Chol. The data for this thesis are mostly from Tila Chol. This dissertation includes aspects of phonology, morphology, and syntax from a contrastive and typological perspective. The grammar begins with general information about the speakers and the language (chapter one). Chapter two is a description of phonology, which includes the inventory of sounds, stress, syllabic patterns and phonological processes. Chapter three presents the properties of root/word classes, as well as affixes and particles. Chapter four is about the person and number markers. Chapter five provides the main features of word classes, such as verbs, nouns, adjectives, positionals, affect words, adverbs, minor classes and clitics. The next chapter (chapter six) deals with the elements that verbs can take, including incorporation of modifiers and noun incorporation. Chapter seven provides the main features of non-verbal predicates. In chapter eight, the structures of noun phrases, such as possessors, determiners and modifiers are presented. Chapter nine describes the structure of simple sentences in both verbal and non-verbal predicates. Chapter ten is devoted to the operations that changevalence, including passive, antipassive, reflexive/reciprocal, causative and applicative. Chapter eleven deals with information structure in the discourse, specifically topicalization and focus. Chapter twelve is a brief description of passive constructions as operations triggered by paradigmatic gaps related to obviation as documented in Algonquian languages. Chapter thirteen deals with complex predicate structures. Finally, in Chapter fourteen, the complex sentences are described, including complement clauses, relative clauses, adverbial clauses, conditional clauses and coordination. This grammar will provide useful information for current Chol projects related to strengthening and revitalization efforts, such as in the construction of pedagogical materials and will also be useful for the field of linguistics or other related areas.Item iFemea (Intelligent Facade Engineered thru Morpho-Ecogenetic Aggregates)(2012-05) Diaz, Rob; Pongratz, Christian; Perbellini, Maria; Park, KuhnThe subject of this thesis is an investigation on an intelligent building skin that improves cross-ventilation (natural) through an embodied space. Intelligent refers to a composite system that either responds to an external energy or a system that can be manipulated and fabricated through a bio-mimetic process. Precedent building skin systems examined in this research provide various technical approaches used to ventilate the building as a "ventilative" device; a means to filter or circulate fresh air from one space to the other. A "mechanical" system will be integrated into a material, controlling possible aperture movements for element (light and/or air) absorption and transmission. The exact configuration will be determined based on the study of biomimicry in plants; which inherits a structure and circulatory system known as the study of morpho-ecogenetics. The aim of this work is to synthesize a membrane with a reinforced mechanical device to influence an aperture operation (open and close) that could be applied to both an external and internal skin of a facade. The term "skin" refers to a light membrane composite that is transparent and malleable and acts as a protective barrier to an interiorly occupied space. The design research will include several test phases that examine the material properties, structure, and applicability when methods such as mechanical, operational, and morphology are integrated.Item Improving spelling ability among speakers of African American vernacular English: an intervention based on phonological, morphological, and orthographic principles(2009-05-15) Pittman, Ramona TrinetteGiven the importance of the role of spelling in literacy, it is important to have knowledge of the linguistic features that allow students to be successful spellers. Having phonological, morphological, and orthographic knowledge is essentially important to spell conventionally. In the United States, the standard language is Academic English (AE). African American Vernacular English (AAVE) is considered a deviation from AE, with its own sound system. AAVE is the most widely used form of dialect in the United States. Many students who speak AAVE may have difficulties in producing the correct spelling of AE words. The overall purpose of this study was to provide sixth-grade students, who are speakers of AAVE, with an eight-week intervention in the principles of phonology, morphology, and orthography that would assist them in improving their spelling performance. Students had similar scores on all spelling and dialect pretest measures before the intervention began. The research design was a pretest/posttest/posttest design using waitlist- control. This study included 142 students divided into 14 class sections taught by two teachers. The two teachers provided the intervention to the students. The experimental group consisted of seven classes, and the control group consisted of seven classes. After the first implementation of the intervention, the study was replicated with the control group of students. MANOVA was utilized to determine the effect of the intervention. The intervention produced large effects for the students who received the spelling instruction. The results from the criterion-referenced spelling assessments and a sentence writing task revealed that students who received explicit instruction from the intervention made gains in their spelling performance from pretest/posttest 1/posttest 2 and maintained these gains after being tested eight weeks later. Practical and theoretical recommendations are provided for teachers and researchers. Suggested recommendations include: providing teacher training that will enable teachers to be more linguistically aware of AAVE and its features, making students aware of the difference in the AAVE and the AE sound system, and conducting more research-based studies that will assist speakers of AAVE in literacy and spelling.Item Methods development and measurements for understanding morphological effects on electronic and optical properties in solution processable photovoltaic materials(2012-12) Ostrowski, David Paul; Vanden Bout, David A.; Rossky, Peter J; Holliday, Bradley J; Korgel, Brian A; Dodabalapur, Ananth JThe effects of morphology on electronic and optical properties in solution processable photovoltaic (PV) materials have been studied through two different approaches. One approach, scanning photocurrent (PC) and photoluminescence (PL) microscopy, involved mapping PC generation and PL in functional PV devices on the length scale of around 250-500 nm. Additionally, local diode characteristics were studied from regions of interest in the PV through local voltage-dependent photocurrent (LVPC) measurements. In a PV made from a Copper Indium Gallium Selenide (CIGS) nanocrystal (NC) "ink", two morphological features were found to cause the spatial heterogeneity in PC generation. Cadmium Sulfide (CdS) aggregates lowered PC generation by blocking incident light to the photoactive layer, and cracks in the CIGS-NC film enhanced PC generation through improved charge carrier extraction. LVPC measurements showed all regions to have similar diode characteristics with the main difference being the PC generated at zero bias voltage. For another PV made from a donor/acceptor blend of poly(9,9-dioctylfluorene-co-bis-N,N-(4-butylphenyl)-bis-N,Nphenyl- 1,4-phenylenediamine (PFB) and poly(9,9-dioctylfluorene-co-benzothiadiazole)(F8BT), two incident laser wavelengths were used to selectively illuminate only one or both polymers. The results showed that when F8BT is illuminated, the PFB-rich regions produced the most PC and when both polymers are illuminated (but mostly PFB), the F8BT-rich regions produce the most PC; showing PC generation is more affective when less absorber material is present in the morphology. The other approach to study morphological effects on PV properties was to fabricate particles that mimicked morphological variations known to occur in solution-processable PVs. Through solution processing of an oligothiophene molecule, a range of weakly coupled H-aggregate particles were made. These particles, identifiable by shape, were shown to have a varying degree of energetic disorder (as gauged by the 0-0 vibronic band intensity in the emission spectrum), despite all particles showing a similarly high degree of molecular order from fluorescence dichroism (FD) measurements. A trend was observed correlating a decrease in energetic disorder with an increase in the local contact potential (LCP) difference as measured with Kelvin probe force microscopy (KPFM). The LCP difference was found to range by 70 mV between particles of moderate to low energetic disorder.Item Morphometric analysis of seven species of pocket gophers (geomyidae)(Texas Tech University, 1996-05) Mauk, Charlene L.Pocket gophers of the genus Geomys (Mammaha, rodentia) are fossorial rodents that are restricted geographically to North and Central America (Hall, 1981) Thirty-eight species and subspecies of Geomys have been recognized from this region (Davis, 1940; Hart, 1978; HaU, 1981). Of this group, G. arenahus, G. attwateri, G. breviceps, G. bursarius, G. knoxjonesi, G. personatus, and G. texensis occur in the southwestern United States. The distribution and diversity of this genus reaches a maximum in the state of Texas where all seven species occur. Consequently, this region (Texas) has received much of the focus of systematic and taxonomic questions. The distribution of members of this genus encompasses all four of the ecological regions of Texas as depicted in Davis and Schmidly (1994). These distributions in Texas can be described as endemic (G. attwateri, G. personatus, and G. texensis), allopatric (G. arenarius), and parapatric (G. attwateri diid G. breviceps, G. attwateri and G. personatus, G. attwateri and G. texensis, G. bursarius and G. breviceps, and G. bursarius and G. knoxjonesi). In addition, sympatric distributions have been identified in the contact zone studies of G. attwateri and G. breviceps (Tucker and Schmidly, 1981; Burton and Bickham, 1989; Dowler, 1989). Specifically, the distributions are as follows. Geomys arenahus is found only in the western Trans-Pecos region along the Rio Grande Valley. The range of G. attwateri includes central Texas west of the Brazos River, south to the San Antonio River, and along the central Gulf coast. Geomys breviceps occurs in the eastern portion (east of the Brazos River) of Texas. Geomys bursarius is located in northwestern and north-central Texas. Geomys knoxjonesi inhabits the deep sandy soils of the southwestern plains of Texas and eastern New Mexico. Geomys personatus occurs throughout most of south Texas, and G. texensis occurs only in two isolated areas of the Texas Hill Country.Item The phonology and inflectional morphology of Cháʔknyá, Tataltepec de Valdés Chatino, a Zapotecan language(2015-05) Sullivant, John Ryan; Woodbury, Anthony C.; England, Nora; Epps, Patience; Myers, Scott; DiCanio, Christian; Rasch, JeffreyThis dissertation is a description of the phonology and inflectional morphology of an endangered indigenous language of Mexico stemming from a collaborative research project that places an emphasis on natural language and on describing a language on its own terms. The language described is Tataltepec Chatino (ISO 639-3: cta), a Zapotecan language spoken by fewer than 500 people only in the community of Tataltepec de Valdés in Mexico's Oaxaca state. The language has a complex system of tone in which tone sequences are the crucial morphological element rather than the constituent tones of the tone sequences. The tone system has a slightly peculiar inventory, with the level tones Low, High, and Superhigh rather than Low, Mid, and High in addition to a High-Low contour tone. The tonal system is also notable given the unlinked tone in two tone sequences which only surfaces in particular phonological contexts, but is never displaced from the word it is associated with, unlike canonical floating tones. The segmental phonology shows a language that permits a large number of often very complex onset clusters many of which violate the Sonority Sequencing Principle, but maintains tight restrictions on codas, allowing only a simple coda which can only be filled by one of two consonants in the language. Tataltepec Chatino also has interesting morphological features in its complex systems of verb aspect and person inflection which are instantiated by a system of prefixes and a system of complex paradigmatic alternations which only partially intersect. The language also has an unusual word I analyze as a "pseudoclassifier" which appears to serve some pragmatic functions of numeral classifiers while failing to do any lexical classification.Item Population structure of the American crocodile (crocodylus acutus) in Coiba Island, Panama, inferred from morphometric measurement and microsatellite markers(2010-12) Garcia, Liza M. M.; Densmore, Llewellyn D.; Bradle, Robert D.; Strauss, Richard E.The purpose of this project was to characterize the genetic and morphological composition of Crocodylus acutus in Coiba Island, Panama, and to infer the population structure derived from the genetic variability between the North and South region of the Island as influenced by geographic barriers and proximity to continental Panama. Multivariate analysis of variance (MANOVA) was performed to analyze the morphometric measurements. The MANOVA for the effect of sample site indicate differences between locations (P = 0.010). Regarding morphometric variables, North and South of Coiba Island overlapped in the discriminant space, but individuals in Mainland were slightly separated from the South of Coiba Island. The analysis of molecular variance (AMOVA) reported a variation among populations of 17.04%, and within populations of 82.96% with an Fst of 0.17 (P < 0.01) implying genetic structure between the populations sampled. The Bayesian analysis based on a clustering method for inferring population structure confirmed the subdivision identifying the maximum likelihood in a K = 3. Geographic barriers influenced the genetic and morphometric variation in the populations of C. acutus in Coiba Island, as confirmed by the presence of three subdivisions, the absence of immigrants and the landscape heterogeneity in the Island. This genetic structure should be considered in conservation programs.Item A re-evaluation of crinoid morphology and proposed relationship of crown groups, with insights from biogeography(2011-08) Womack, Kyle Richard; Sprinkle, James, 1943-; Molineux, Ann; Rowe, TimothyCrinoids are the most primitive living members of the Phylum Echinodermata. Though still present in reduced numbers today, crinoids were the dominant echinoderms from the Ordovician to the Permian. The crinoid body plan consists of three major regions, the column, the calyx, and the arms. Each region serves important functions in crinoids. The column raises the rest of the body into the water column for more efficient feeding. The calyx contains the visceral mass and mouth. Arms extend out from the top of the calyx to trap microorgansisms and suspended organic particles in the water column. A re-evaluation of these functional units is undertaken to understand the importance of various structures and to obtain discrete characters for use in a cladistic analysis. The relationship of crinoid crown groups has been an active area of research for the past couple of decades. With each proposed phylogenetic relationship, a new interpretation of thecal plate homology has been proposed. Here each study is re-examined in the light of new data. A review of functional morphology indicates a dual-reference system to be the most supported interpretation of plate homology. The two reference points in this system are the stem-cup and the cup-arm junctions, at the top and bottom of the calyx. The difference between a two-circlet and three-circlet crinoid is the presence or absence of the middle (basal) circlet. A new cladistic analysis is presented, with the topology of trees obtained giving support for the retention of Paleozoic crinoid stem and crown groups. Crinoids appear abruptly in the fossil record. Questions pertaining to origins and ancestral stock abound. A biogeography study is employed to look at the distribution of crinoids from the Early to Middle Ordovician. Locality information, combined with an understanding of the movement of major plates, paleoclimate data, an understanding of larval distribution, and a review of similar studies carried out on different taxa, gives insight into possible radiation and dispersal patterns of crinoids from the first half of the Ordovician.