Biology Commons^™

Remarks On The Stability Of Some Size-Structured Population Models Iv: The General Case Of Juveniles And Adults, M. El-Doma

Applications and Applied Mathematics: An International Journal (AAM)

The stability of some size-structured population dynamics models is investigated when the population is divided into adults and juveniles. We determine the steady states and study their stability. We also give examples that illustrate the stability results. The results in this paper generalize previous results, for example, see Calsina, et al. (2003), El-Doma (2006), Farkas, et al. (2008), and El-Doma (2008 a).

Two-Layered Model Of Blood Flow Through Composite Stenosed Artery, Padma Joshi, Ashutosh Pathak, B. K. Joshi

Applications and Applied Mathematics: An International Journal (AAM)

In this paper a steady, axisymmetric flow, with a constricted tube has been studied. The artery has been represented by a two-layered model consisting of a core layer and a peripheral layer. It has been shown that the resistance to flow and wall shear stress increases as the peripheral layer viscosity increases. The results are compared graphically with those of previous investigators. It has been observed that the existence of peripheral layer is useful in representation of diseased arterial system.

Protein Secondary Structure Prediction Using Parallelized Rule Induction From Coverings, Leong Lee, Cyriac Kandoth, Jennifer Leopold, Ronald L. Frank

Computer Science Faculty Research & Creative Works

Protein 3D structure prediction has always been an important research area in bioinformatics. In particular, the prediction of secondary structure has been a well-studied research topic. Despite the recent breakthrough of combining multiple sequence alignment information and artificial intelligence algorithms to predict protein secondary structure, the Q3 accuracy of various computational prediction algorithms rarely has exceeded 75%. In a previous paper [1], this research team presented a rule-based method called RT-RICO (Relaxed Threshold Rule Induction from Coverings) to predict protein secondary structure. The average Q3 accuracy on the sample datasets using RT-RICO was 80.3%, an improvement over comparable computational methods. …

Population Ecology And Reproductive Biology Of The Diamondback Watersnake, Nerodia Rhombifer (Serpentes: Colubridae), In Southernmost Texas, Ruben D. Zamora

Theses and Dissertations - UTB/UTPA

Nerodia rhombifer is a polytypic, semi-aquatic snake with a broad geographical distribution ranging from the American Midwest southward to Chiapas, Mexico. Although relatively abundant throughout much of its range, few ecological studies of the species have been conducted. This study provides basic population ecology information in a subtropical habitat. Population data were obtained in a mark-recapture study at Santa Ana National Wildlife Refuge, Hidalgo County, Texas, from August 1995 to December 1998. Specimens taken elsewhere in Hidalgo County provided information on the reproductive biology. This study provides the first absolute density estimates from anywhere within the species’ range. Quantitative information …

Conservation Genetics And Systematics Of Several Turtles Species In The Southeastern United States, Joshua Robert Ennen

Dissertations

Chelonians (i.e., turtles) are an imperiled group of reptiles with about 66% of the recognized species listed as threatened by the IUCN. Most chelonian species have a unique set of life history traits (i.e., longevity, delayed sexual maturity, and low juvenile survivorship), which makes their populations exceedingly sensitive to increases in adult and juvenile moralities. With numerous anthropogenic effects (e.g., habitat alteration, exploitation, and over harvesting) negatively influencing mortality rates, chelonians have experienced global precipitous declines and extinctions.

This dissertation focuses on species within two chelonian genera, Gopherus and Graptemys. Although these two genera are vastly different ecologically, they are …

Gold Nanoparticle Interactions And Impact Upon A Common Biofilm Source: Legionella Pneumophila , Amber Stojak

All Theses

There exists widespread concern of pathogenic bacteria colonizing and establishing biofilms in water systems providing a direct exposure route to the public. Legionella are widely distributed in human-made and natural environments, and colonization lends the potential to infect human hosts that may lead to the development of Legionnaire's Disease. Silver has been used in cooling towers and water filtration systems for removal of planktonic bacteria and biofilms; however permanent removal of L. pneumophila biofilms with metal ions is impossible when established biofilms are in hard to access places such as dead end piping or inside a protozoan host. Bulk metals …

Using A Multimedia Assessment Tool To Impact Evolution Education Strategies In South Carolina's Public High Schools, Matthew Johnson

All Theses

The theory of evolution is widely accepted as one of the fundamental disciplines of modern science. Evolution provides a foundation for all aspects of biology, and thus it is essential that present and future biologists have a detailed understanding of evolutionary principles. However, since the famous Scopes trial in 1925, the teaching of evolutionary theory in the public school system has been under attack. Though several court cases over the last 85 years have continually supported evolution and discredited creationism (the idea that evolution cannot explain the diversity of life on earth and therefore must have arisen through the influence …

Isoform- And Cell-Specific Function Of Tyrosine Decarboxylase In The Drosophila Malpighian Tubule, Edward M. Blumenthal

Biological Sciences Faculty Research and Publications

The biogenic amine tyramine (TA) is a potent diuretic factor when applied to the Malpighian tubule (MT) of Drosophila melanogaster, stimulating both urine production and transepithelial chloride conductance. Isolated MTs can respond not only to TA but also to its precursor, tyrosine; this observation led to the proposal that MTs are able to synthesize TA from applied tyrosine through the action of the enzyme tyrosine decarboxylase (TDC). In the current study it is shown that the non-neuronal isoform of TDC, Tdc1, is expressed in the principal cells of the MT. A mutant allele of Tdc1, Tdc1^{f03311 …}

Seasonality And Movement Of Adventive Populations Of The Arundo Wasp (Hymenoptera: Eurytomidae), A Biological Control Agent Of Giant Reed In The Lower Rio Grande Basin In South Texas, Alexis Racelis, Carol Goolsby, Patrick J. Moran

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The arundo wasp, Tetramesa romana Walker, has been permitted as a biological control agent for the invasive perennial grass, the giant reed, Arundo donax L. Evidence of adventive populations of the arundo wasp in the Lower Rio Grande Basin was confirmed with a spatio-temporal survey spanning more than 350 river miles. A total of 2,414 adult females of T. romana was collected during a 14month period of study in 2008–2009. This study documents the initial locations and regional expansion of two adventive populations of T. romana, centered around the cities of Eagle Pass and Laredo, TX. Peaks in T. …

Proteomic Analysis Of Blastema Formation In Regenerating Axolotl Limbs, Nandini Rao, Deepali Jhamb, Derek J. Milner, Bingbing Li, Fengyu Song, Mu Wang, S. Randal Voss, Mathew Palakal, Michael W. King, Behnaz Saranjami, Holly L.D. Nye, Jo Ann Cameron, David L. Stocum

Biology Faculty Publications

BACKGROUND: Following amputation, urodele salamander limbs reprogram somatic cells to form a blastema that self-organizes into the missing limb parts to restore the structure and function of the limb. To help understand the molecular basis of blastema formation, we used quantitative label-free liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS)-based methods to analyze changes in the proteome that occurred 1, 4 and 7 days post amputation (dpa) through the mid-tibia/fibula of axolotl hind limbs.

RESULTS: We identified 309 unique proteins with significant fold change relative to controls (0 dpa), representing 10 biological process categories: (1) signaling, (2) Ca2+ binding and translocation, (3) transcription, …

Prothonotary Warbler (Protonotaria Citrea) Plumage As An Indicator For Infection: The Relationship Between Haemosporidia Infection And Breast Feather Reflectance In A Neotropical Migrant Passerine, Robert Fithian

Theses and Dissertations

Yellow avian plumage is a direct result of carotenoid pigments obtained in a bird’s diet and may act as an indicator for individual health, parasite resistance, and status. This study describes breast feather reflectance of adult Prothonotary Warblers (Protonotaria citrea) (n=169), insectivorous Neotropical migrant passerines, throughout the Ultraviolet (UV) and human visible light spectra and examines the relationship between Haemosporidia (pathogen causing Avian Malaria) infection and feather reflectance (n=41). Reflectance was characterized using a Principle Component Analysis evaluating Intensity, Brightness, Hue, UV Intensity, UV Brightness, and UV Chroma. UV and visible light reflectance was higher in birds sampled earlier in …

Ceramide Kinase Regulates Phospholipase C And Phosphatidylinositol 4, 5, Bisphosphate In Phototransduction, Ujjaini Dasgupta, Takeshi Bamba, Salvatore Chiantia, Pusha Karim, Ahmad N. Abou Tayoun

Dartmouth Scholarship

Phosphoinositide-specific phospholipase C (PLC) is a central effector for many biological responses regulated by G-protein-coupled receptors including Drosophila phototransduction where light sensitive channels are activated downstream of NORPA, a PLCbeta homolog. Here we show that the sphingolipid biosynthetic enzyme, ceramide kinase, is a novel regulator of PLC signaling and photoreceptor homeostasis. A mutation in ceramide kinase specifically leads to proteolysis of NORPA, consequent loss of PLC activity, and failure in light signal transduction. The mutant photoreceptors also undergo activity-dependent degeneration. Furthermore, we show that a significant increase in ceramide, resulting from lack of ceramide kinase, perturbs the membrane microenvironment of …

Susceptibility Of Caenorhabditis Elegans To Burkholderia Infection Depends On Prior Diet And Secreted Bacterial Attractants, Vaughn S. Cooper, Wendy A. Carlson, John J. Lipuma

Molecular, Cellular & Biomedical Sciences

The nematode Caenorhabditis elegans may be killed by certain pathogenic bacteria and thus is a model organism for studying interactions between bacteria and animal hosts. However, growing nematodes on prey bacteria may influence their susceptibility to potential pathogens. A method of axenic nematode culture was developed to isolate and quantify interactions between C. elegans and potentially pathogenic strains of the Burkholderia cepacia complex. Studying these dynamics in liquid solution rather than on agar surfaces minimized nematode avoidance behavior and resolved more differences among isolates. Most isolates of B. cenocepacia, B. ambifaria and B. cepacia caused 60-80% mortality of nematodes after …

Evaluating Forensic Dna Evidence, Dan E. Krane

Biological Sciences Faculty Publications

No abstract provided.

Quantifying And Resolving Multiple Vector Transformants In S. Cerevisiae Plasmid Libraries, Thomas C. Scanlon, Elizabeth C. Gray, Karl E. Griswold

Dartmouth Scholarship

In addition to providing the molecular machinery for transcription and translation, recombinant microbial expression hosts maintain the critical genotype-phenotype link that is essential for high throughput screening and recovery of proteins encoded by plasmid libraries. It is known that Escherichia coli cells can be simultaneously transformed with multiple unique plasmids and thusly complicate recombinant library screening experiments. As a result of their potential to yield misleading results, bacterial multiple vector transformants have been thoroughly characterized in previous model studies. In contrast to bacterial systems, there is little quantitative information available regarding multiple vector transformants in yeast. Saccharomyces cerevisiae is the …

Monitoring Heart Function In Larval Drosophila Melanogaster For Physiological Studies, Ann S. Cooper, Kylah E. Rymond, Matthew A. Ward, Easter L. Bocook, Robin L. Cooper

Biology Faculty Publications

We present various methods to record cardiac function in the larval Drosophila. The approaches allow heart rate to be measured in unrestrained and restrained whole larvae For direct control of the environment around the heart another approach utilizes the dissected larvae and removal of the internal organs in order to bathe the heart in desired compounds. The exposed heart also allows membrane potentials to be monitored which can give insight of the ionic currents generated by the myocytes and for electrical conduction along the heart tube. These approaches have various advantages and disadvantages for future experiments that are discussed. …

Indications Of Potential Toxic/Mutagenic Effects Of World Trade Center Dust On Human Lung Cell Cultures, Constantino G. Lambroussis, Barbara D. Soares, Sergio Perez, David Gaipa, Anise L. Elie, Caitlin M. Ament, Fahad T. Rouf, Lotfi M. Bassa, Ann Marie Dilorenzo

Department of Biology Faculty Scholarship and Creative Works

Problem statement: Respiratory complications have been linked with exposure to dust particulates after the tragedy of September 11th, 2001 at the World Trade Center (WTC) site. Approach: The purpose of these experiments was to investigate the extent of cellular damage resulting from WTC dust exposure. Results: This research project was conducted with human lung fibroblast cells exposed to WTC dust. To determine if cell proliferation levels were affected, cultured cells were exposed to WTC dust at various concentrations in simulated physiological stress environments via decreased serum levels. Results indicated that cell proliferation levels decreased as WTC dust concentrations increased. This …

Immunisation With A Multivalent, Subunit Vaccine Reduces Patent Infection In A Natural Bovine Model Of Onchocerciasis During Intense Field Exposure, Benjamin L. Makepeace, Siv Aina Jensen, Sandra J. Laney, Charles K. Nfon, Leo M. Njongmeta, Vincent N. Tanya, Steven A. Williams, Albert E. Bianco, Alexander J. Trees

Biological Sciences: Faculty Publications

Human onchocerciasis, caused by the filarial nematode Onchocerca volvulus, is controlled almost exclusively by the drug ivermectin, which prevents pathology by targeting the microfilariae. However, this reliance on a single control tool has led to interest in vaccination as a potentially complementary strategy. Here, we describe the results of a trial in West Africa to evaluate a multivalent, subunit vaccine for onchocerciasis in the naturally evolved host-parasite relationship of Onchocerca ochengi in cattle. Na ̈ıve calves, reared in fly-proof accommodation, were immunised with eight recombinant antigens of O. ochengi, administered separately with either Freund’s adjuvant or alum. The selected antigens …

Intraspecific Phylogeography Of Cycladenia Humilis (Apocynaceae), Mariana P. Last

Theses and Dissertations

Cycladenia humilis (Apocynaceae) is a rare perennial herb native to western North America and has a fragmented distribution in California, Utah, and Arizona. Populations in Utah and Arizona are federally listed as threatened, while there is no conservation status applied to California populations. Using genetic (three chloroplast and two nuclear DNA loci) and morphological characters, intraspecific variation between populations of C. humilis and current taxonomic conventions were assessed. Nested Clade Phylogeographic Analysis and Bayesian phylogenies were used to assess patterns within C. humilis and supported three main population groupings: a northern California, southern California, and Colorado Plateau group. The northern …

Historical View And Physiology Demonstration At The Nmj Of The Crayfish Opener Muscle, Ann S. Cooper, Robin L. Cooper

Biology Faculty Publications

Here we present some of the key important discoveries made with the opener neuromuscular (NMJ) preparation of crustaceans and illustrate that there is still much to learn from this model preparation. In understanding the history one can appreciate why even today this NMJ still offers a rich playground to address questions regarding pre- and post-synaptic function and plasticity. The viability and ease of access to the terminal for intracellular as well as extracellular electrophysiology and imaging are significant advantages. The mechanisms behind the modulation of vesicular kinetics and fusion within the high- and low-output terminals are begging for investigation. The …

The Importance Of Fallback Foods In Primate Ecology And Evolution, Paul J. Constantino, Barth W. Wright

Biological Sciences Faculty Research

The role of fallback foods in shaping primate ranging, socioecology, and morphology has recently become a topic of particular interest to biological anthropologists. Although the use of fallback resources has been noted in the ecological and primatological literature for a number of decades, few attempts have been made to define fallback foods or to explore the utility of this concept for primate evolutionary biologists and ecologists. As a preface to this special issue of the American Journal of Physical Anthropology devoted to the topic of fallback foods in primate ecology and evolution, we discuss the development and use of the …

Effects Of Participation In Inquiry Science Workshops And Follow-Up Activities On Middle School Science Teachers' Content Knowledge, Teacher-Held Misconceptions, And Classroom Practices, Linda F. Cepeda

Electronic Theses and Dissertations

An important aspect of developing science literacy for all students is developing science-literate teachers. With the implementation of the No Child Left Behind Act, many middle school teachers found themselves in a position where they were no longer qualified to teach middle school science. This study was designed to help science teachers increase their science content knowledge, identify and resolve misconceptions/errors they may have, and assist them in their teaching by providing strategies for inquiry-based teaching, science laboratory exercises, and science equipment.

Teachers enrolled in biology courses offered by the Rocky Mountain Middle School Math and Science Partnership participated in …

Exhaustive Exercise Training Enhances Aerobic Capacity In American Alligator (Alligator Mississippiensis), John Eme, Tomasz Owerkowicz, June Gwalthney, Jason M. Blank, Bryan C. Rourke, James W. Hicks

Biological Sciences

The oxygen transport system in mammals is extensively remodelled in response to repeated bouts of activity, but many reptiles appear to be ‘metabolically inflexible’ in response to exercise training. A recent report showed that estuarine crocodiles (Crocodylus porosus) increase their maximum metabolic rate in response to exhaustive treadmill training, and in the present study, we confirm this response in another crocodilian, American alligator (Alligator mississippiensis). We further specify the nature of the crocodilian training response by analysing effects of training on aerobic [citrate synthase (CS)] and anaerobic [lactate dehydrogenase (LDH)] enzyme activities in selected skeletal muscles, …

Surgical Removal Of Right-To-Left Cardiac Shunt In The American Alligator (Alligator Mississippiensis) Causes Ventricular Enlargement But Does Not Alter Apnoea Or Metabolism During Diving, John Eme, June Gwalthney, Jason M. Blank, Tomasz Owerkowicz, Gildardo Barron, James W. Hicks

Biological Sciences

Crocodilians have complete anatomical separation between the ventricles, similar to birds and mammals, but retain the dual aortic arch system found in all non-avian reptiles. This cardiac anatomy allows surgical modification that prevents right-to-left (R–L) cardiac shunt. A R–L shunt is a bypass of the pulmonary circulation and recirculation of oxygen-poor blood back to the systemic circulation and has often been observed during the frequent apnoeic periods of non-avian reptiles, particularly during diving in aquatic species. We eliminated R–L shunt in American alligators (Alligator mississippiensis) by surgically occluding the left aorta (LAo; arising from right ventricle) upstream and …

The Development And Role Of Peripheral Auditory Structures In Otocinclus Affinis, Sri Kiran Kumar Reddy Botta

Masters Theses & Specialist Projects

Loricariidae is a very diverse family of catfishes found primarily in the Amazon River basin. These catfishes have a unique characteristic feature of having fenestrae (holes) in the skull region (compound pterotic bone) adjacent to their bi-lobed swim bladder. Since the swim bladders and the compound pterotic may act as an external ear for hearing in this taxon, I hypothesized that these swim bladders structures have an acoustical functional in the loricariid Otocinclus affinis. In order to understand the development of these structures in O. affinis, I first monitored the ontogeny of the compound pterotic bone by clearing …

E Unibus Plurum: Genomic Analysis Of An Experimentally Evolved Polymorphism In Escherichia Coli, Margie A. Kinnersley, William E. Holben, Frank Rosenzweig

Biological Sciences Faculty Publications

Microbial populations founded by a single clone and propagated under resource limitation can become polymorphic. We sought to elucidate genetic mechanisms whereby a polymorphism evolved in Escherichia coli under glucose limitation and persisted because of cross-feeding among multiple adaptive clones. Apart from a 29 kb deletion in the dominant clone, no large-scale genomic changes distinguished evolved clones from their common ancestor. Using transcriptional profiling on co-evolved clones cultured separately under glucose-limitation we identified 180 genes significantly altered in expression relative to the common ancestor grown under similar conditions. Ninety of these were similarly expressed in all clones, and many of …

Phylogeography Of The Frog Leptodactylus Validus (Amphibia: Anura): Patterns And Timing Of Colonization Events In The Lesser Antilles, Arley Camargo, W. Ronald Heyer, Rafael O. De Sá

Biology Faculty Publications

The frog Leptodactylus validus occurs in northern South America, Trinidad and Tobago, and the southern Lesser Antilles (Grenada and St. Vincent). Mitochondrial DNA sequences were used to perform a nested clade phylogeographic analysis (NCPA), to date colonization events, and to analyze colonization patterns using on a relaxed molecular clock and coalescent simulations. L. validus originated on the mainland and first colonized Trinidad with subsequent independent colonizations of Tobago and the Lesser Antilles from Trinidad. The NCPA suggests a historical vicariant event between populations in Trinidad and Tobago from those in the Lesser Antilles. The colonization of Trinidad occurred 1 million …

Molecular And Chromosomal Evidence For Allopolyploidy In Soybean, Navdeep Gill, Seth Findley, Jason G. Walling, Christian Hans, Jianxin Ma, Jeff Doyle, Gary Stacey, Scott A. Jackson

Biology Faculty Articles

Recent studies have documented that the soybean (Glycine max) genome has undergone two rounds of large-scale genome and/or segmental duplication. To shed light on the timing and nature of these duplication events, we characterized and analyzed two subfamilies of high-copy centromeric satellite repeats, CentGm-1 and CentGm-2, using a combination of computational and molecular cytogenetic approaches. These two subfamilies of satellite repeats mark distinct subsets of soybean centromeres and, in at least one case, a pair of homologs, suggesting their origins from an allopolyploid event. The satellite monomers of each subfamily are arranged in large tandem arrays, and intermingled …

Novel Lc8 Mutations Have Disparate Effects On The Assembly And Stability Of Flagellar Complexes, Pinfen Yang, Chun Yang, Maureen Wirschell, Stephanie Davis

Biological Sciences Faculty Research and Publications

LC8 functions as a dimer crucial for a variety of molecular motors and non-motor complexes. Emerging models, founded on structural studies, suggest that the LC8 dimer promotes the stability and refolding of dimeric target proteins in molecular complexes, and its interactions with selective target proteins, including dynein subunits, is regulated by LC8 phosphorylation, which is proposed to prevent LC8 dimerization. To test these hypotheses in vivo, we determine the impacts of two new LC8 mutations on the assembly and stability of defined LC8-containing complexes in Chlamydomonas flagella. The three types of dyneins and the radial spoke are disparately affected …

Cross-Sectional Dating Of Novel Haplotypes Of Herv-K 113 And Herv-K 115 Indicate These Proviruses Originated In Africa Before Homo Sapiens, Aashish Jha, Satish Pillai, Vanessa York, Elizabeth Sharp, Emily Storm, Douglas Wachter, Jeffrey Martin, Steven Deeks, Michael Rosenberg, Douglas Nixon, Keith Garrison

School of Science Faculty Works

The human genome, human endogenous retroviruses (HERV), of which HERV-K113 and HERV-K115 are the only known full-length proviruses that are insertionally polymorphic. Although a handful of previously published papers have documented their prevalence in the global population; to date, there has been no report on their prevalence in the United States population. Here, we studied the geographic distribution of K113 and K115 among 156 HIV-1+ subjects from the United States, including African Americans, Hispanics, and Caucasians. In the individuals studied, we found higher insertion frequencies of K113 (21%) and K115 (35%) in African Americans compared with Caucasians (K113 9% and …