Studies on the Drumming Behavior of North American Stoneflies (Plecoptera) (open access)

Studies on the Drumming Behavior of North American Stoneflies (Plecoptera)

Drumming behavior is described for the first time in 16 North American species of Plecoptera, and signals of a 17th species, Isogenoides zionensis, are further detailed. The effective distance over which drumming signals may be transmitted was tested for four communication modes. Results indicate that substratum vibrations are far superior to sound in the transmission of drumming signals, and that dense substrates such as rocks are poor channels for signal transfer. Long communication periods between stonefly pairs of Taeniopteryx burksi resulted in some alterations from initial signaling characteristics.
Date: May 1984
Creator: Zeigler, David D.
System: The UNT Digital Library
An Interpretation of Archaic Medical Treatises (open access)

An Interpretation of Archaic Medical Treatises

Ancient peoples did not distinguish between philosophy, religion, and science. Scientific truth did not exist apart from divine truth. Any new idea, finding, or theory was assimilated into a monolithic mythological structure. This is one of the causes of the underestimation of ancient science: it is always packaged in a myth - the method of preserving information in an oral culture. The mythological medium allowed the preservation and dissemination of hard-won, empirical, scientific knowledge through generations of preliterate peoples. The context for mythological memorization, or simply tradition, needed to be easily and naturally acquired. The ideal context was the anthropomorphic context, the ontogenic context. This is the Grand Allegory - the anthropomorphization of information. Biomyths are essentially biological texts allegorized in esoteric language.
Date: May 1993
Creator: Wagers, William D. (William Delbert)
System: The UNT Digital Library
Key Factors Influencing Retention Rates among Historically Underrepresented Student Groups in STEM Fields (open access)

Key Factors Influencing Retention Rates among Historically Underrepresented Student Groups in STEM Fields

The aim of the study was to identify the factors that have an influence on the completion rates of undergraduate students in the fields of science, technology, engineering and mathematics (STEM). Using Tinto's retention rate theory as the theoretical foundation, data were collected from freshman who were enrolled in the years 2005 to 2008. Results showed gender and first-generation status were significant predictors of STEM completion and time taken to complete the degree. Institutional bias played a role in race/ethnicity not being a factor affecting completion rates, as this study was conducted at a Predominantly White Institution. SAT scores and first and second-year college GPA showed to have the most prominent influence on both STEM completion rate and time taken to complete the degree. Females with higher first-year college GPA and higher high school rank finished faster. Similar results were found with first-generation students as well. Students belonging to ethnic minority groups with higher SAT scores and college GPA had greater success in STEM fields as well. The study results can be used to increase completion rates of underrepresented students in the STEM fields, given what we know about the interactions between underrepresented student groups and the most important predictors.
Date: December 2018
Creator: Premraj, Divya
System: The UNT Digital Library
The Effectiveness of Hybrid Problem-Based Learning versus Manual-Based Learning in the Microbiology Laboratory (open access)

The Effectiveness of Hybrid Problem-Based Learning versus Manual-Based Learning in the Microbiology Laboratory

Promising results from the use of problem-based learning (PBL) as a teaching method in medical programs have encouraged many institutions to incorporate PBL into their curricula. This study investigates how applying hybrid-PBL (H-PBL) in a microbiology laboratory impacts students' higher-order thinking as compared to applying a lecture-based pedagogy. The experimental design compared the learning outcomes of two groups of students: the control group and the H-PBL group, for whom PBL cases comprised 30% of the curriculum. Both groups were taught basic skills for the microbiology lab by the same instructor. Using the traditional teaching style for the control group, the instructor offered each student what they needed for their experiments. The H-PBL group practiced experimental design, data analysis, theory proposal, and created research questions by using six study cases that were closely linked to the area of study. The outcome was measured using a pre- and post- assessment consisting of 24 questions that was designed by following Bloom's taxonomy of learning levels. A one-way ANOVA was used to analyze the data. The results showed that for the first three levels of Bloom's taxonomy— knowledge, comprehension, and application—there were no statistically significant differences between the H-PBL and control group gain scores …
Date: May 2017
Creator: Alharbi, Najwa
System: The UNT Digital Library
The stonefly genus Isogenoides Klapálek (Plecoptera: Perlodidae) of North America: Systematics, behavior and ecology. (open access)

The stonefly genus Isogenoides Klapálek (Plecoptera: Perlodidae) of North America: Systematics, behavior and ecology.

The stonefly genus Isogenoides is revised following a holomorphological approach utilizing traditional morphology and behavioral lines of evidence. Species keys are provided for all life stages. One species, I. krumholzi (Ricker) is considered a synonym of I. doratus (Frison). Detailed species descriptions are provided for males, females, nymphs and ova. Distributions are updated utilizing all known published accounts and materials examined. The vibrational communication (drumming) behavior is reported for males and all but one species for females. The signals were species-specific and ranged in complexity from ancestral sequenced duets to derived grouped exchanges. I. olivaceus is least specialized, having mostly sequenced duets, and I. zionensis most specialized, displaying ancestral sequenced, derived grouped and complex derived exchanges containing both sequenced and grouped elements. Laboratory egg incubation experiments over a 2-4 year period show that Isogenoides has a great capacity for extended, sometimes-asynchronous diapause and hatching. The eggs of six species were incubated at a single, ca. simulated San Miguel River, Colorado, seasonal temperature regime. Direct hatch within two weeks occurred only for I. zionensis (Leopard Creek, Colorado) with small numbers hatching again after one, two, and four years. Eggs of I. doratus and I. varians hatched after an over summer, 3-5 …
Date: May 2005
Creator: Sandberg, John Burton
System: The UNT Digital Library
Characterizing Spontaneous Neurophysiological Activity with Measures of Statistical Serial Dependence: a Summary Statistic and an Extension of the Joint Interval Histogram (open access)

Characterizing Spontaneous Neurophysiological Activity with Measures of Statistical Serial Dependence: a Summary Statistic and an Extension of the Joint Interval Histogram

Two measures which indicate statistical serial dependence were evaluated. The n-dimensional Average Stored Information index (ndASI) is a measure of conditional information, which compares the entropies of higher order conditional distributions to estimate average statistical serial dependence. The generalized ranked joint interval histogram (RJIH-o) is a new nonparametric graphical analysis method. It extends the joint interval histogram by depicting longer interval sequences and can be interpereted precisely analagously to the joint interval histogram. The generalized ranked joint interval histogram correctly represents independence in a Poisson process model and statistical serial dependence in a directionally reinforced Markov model. The generalized ranked joint interval histogram correctly depicts the underlying periodic and strange attractors in a standard map model. Both measures can be used to effectively analyze interspike interval sequences from spontaneous neurophsyiological activity effectively.
Date: August 1994
Creator: Weil, Jon C. (Jon Christopher)
System: The UNT Digital Library
A Socio-ecological Assessment of Watershed Ecosystem Services in Southern Patagonia (open access)

A Socio-ecological Assessment of Watershed Ecosystem Services in Southern Patagonia

This thesis utilizes a theoretical framework which links biophysical and social domains of ecosystems via ecosystem services (ES), in order to conduct a socio-ecological assessment of urban watersheds in three communities in Chilean and Argentine regions of southern Patagonia. Results from this study show that expanding urban areas may be undermining the ability of local watersheds to provide for high quality ES posing potential risks to community wellbeing. Secondly, researchers and decision makers influencing regional natural resource management share similar values to general community members but do not capture the diversity of values that exist within the broader community, and dialogue between these groups on management issues is poor. A community-based management structure is recommended for the creation of adaptive and locally relevant management strategies.
Date: August 2012
Creator: Zagarola, Jean-Paul Aguirre
System: The UNT Digital Library
Anatomy and Physiology Syllabus for Community Colleges (open access)

Anatomy and Physiology Syllabus for Community Colleges

This syllabus includes both lecture notes and laboratory activities for a two-semester anatomy and physiology community college course. The syllabus is based on a 16-week semester that is comprised of a three-hour lecture section and a one-hour laboratory class each week. Both the lecture course and laboratory are necessary to fulfill the requirement for anatomy and physiology. Laboratory activities coincide with lectures to enhance understanding of each topic by providing visual and hands-on experiments for the concepts learned in the lecture. Laboratory quizzes will be given each week to help students maintain a working knowledge of the material learned in the laboratory. This course is appropriate for the typical anatomy and physiology student and should benefit both students who plan to major in biology and also those who are non-biology majors. Because subject matter in anatomy and physiology is quite difficult, the importance of attendance and good study skills is stressed.
Date: May 2000
Creator: Schulz, Leslie
System: The UNT Digital Library
Museum education: Creation, implementation, and evaluation of a web-based Elm Fork Natural Heritage Museum (open access)

Museum education: Creation, implementation, and evaluation of a web-based Elm Fork Natural Heritage Museum

Evaluation of museum audiences both in their physical and web-based spaces is a necessary component of museum education. For smaller museums without the personnel or knowledge to create a website and evaluate the on-line audience, using a web-based learning tool may be able to help these museums properly maintain an online site. A web-based Elm Fork Natural Heritage Museum (WBEFNHM) was created during the 2008 fall semester at the University of North Texas. The site included photographs and information from specimens housed within the physical Elm Fork Natural Heritage Museum. The site was available to three non-science majors' biology laboratory courses, and three science majors' biology laboratory courses during the 2009 spring and fall semesters. Student use of the WBEFNHM was tracked and found no significant difference between the amount of time science majors and non-majors spent on the site. This evaluation helps in understanding future use of an online EFNHM.
Date: December 2010
Creator: Lundeen, Melissa
System: The UNT Digital Library
Studies of Odor-Producing Actinomycete Response to Selected Geosmin Concentrations (open access)

Studies of Odor-Producing Actinomycete Response to Selected Geosmin Concentrations

The purpose of this investigation was to explore how geosmin, an odorous compound produced by certain algae and actinomycetes, may affect the growth of a selected, odor producing actinomycete of the genus Streptomyces.
Date: August 1971
Creator: Camp, Frank A.
System: The UNT Digital Library
Life History Allocation of Energy to Growth and Reproduction in Gizzard Shad, Dorosoma cepedianum, in North Central Texas (open access)

Life History Allocation of Energy to Growth and Reproduction in Gizzard Shad, Dorosoma cepedianum, in North Central Texas

Life history allocation of energy to growth and reproduction was determined for female gizzard shad. Absolute caloric energy allocated to eggs increased with age. The relative amount of production energy directed to reproduction increased with age up to 5 years and then decreased. Seasonal variation in lipids was studied. Quantitative changes occurred in ovarian lipids during the reproductive cycle. Carcass lipids varied seasonally. Age of sexual maturity was 3 years. Delayed maturity is attributed to high allocation of energy to growth enabling shad to outgrow intense competition and predation in pre-reproductive ages; there is little competition and predation in reproductive shad. Growth rates and condition factors indicated constant availability of food seasonally.
Date: December 1976
Creator: Fagan, Joseph A.
System: The UNT Digital Library
Studies on the Morphology and Biology of Cotton Rats (Sigmodon hispidus) from Northern Mexico to Southern Nebraska (open access)

Studies on the Morphology and Biology of Cotton Rats (Sigmodon hispidus) from Northern Mexico to Southern Nebraska

This investigation was designed to evaluate the need for retaining both Sigmodon hispidus texianus and Sigmodon hispidus berlandieri as subspecific designations. An attempt was made to demonstrate bioclimatic variation and reproductive seasonality in cotton rats. The validity of applying the results of isolated studies of cotton rat populations to the species as a whole was examined.
Date: December 1971
Creator: Cleveland, Arthur Gordon
System: The UNT Digital Library
Effects of Ribavirin on Normal Rat Kidney Cells and Chicken Embryo Fibroblasts Infected with Rous Sarcoma Virus (open access)

Effects of Ribavirin on Normal Rat Kidney Cells and Chicken Embryo Fibroblasts Infected with Rous Sarcoma Virus

Ribavirin, a synthetic nucleoside, was found to inhibit the replication of Rous sarcoma viruses (RSV) and subsequent cell transformation in chick embryo fibroblasts (CEF). It also blocked the transformation of normal rat kidney (NRK) cells infected with temperature-sensitive mutants of RSV. The action of Ribavirin was found to be reversible as removal of the drug from the NRK cells reversed the effects on cell transformation. Ribavirin appears to have a static effect on cell growth of both NRK and CEF cells. In addition, guanosine, xanthosine and inosine altered the effect of Ribavirin on cell growth.
Date: April 1979
Creator: Jenkins, Frank J.
System: The UNT Digital Library
Permeability of the Kidney Capillaries to Narrow-Range Macromolecular Dextran Fractions (open access)

Permeability of the Kidney Capillaries to Narrow-Range Macromolecular Dextran Fractions

Recent investigations into the permeability of the kidney capillaries have produced conflicting reports. This study was an attempt to better describe the permeability of the kidney capillaries by using narrow-range macromolecular dextran fractions in four molecular sizes: MW 61,400, MW 77,000, MW 118,000, and MW 147,000. Permeability was measured by dextran concentration differences in plasma and kidney lymph. Permeability decreased as the dextran molecular weight increased. Molecular weights 61,400 and 77,000 penetrated into the kidney lymph. Molecular weight 118,000 exhibited greater difficulty in penetrating to the lymph. The largest fraction penetrated into the kidney lymph with greatest difficulty. Plasma expansion by saline infusion increased the permeability of all dextran fractions.
Date: August 1979
Creator: Wooldridge, Clayton Bradley
System: The UNT Digital Library
Ecological Association Between the Red-Cockaded Woodpecker and Southern Pine Beetle in the Homochitto National Forest: a Geographic Information System Approach (open access)

Ecological Association Between the Red-Cockaded Woodpecker and Southern Pine Beetle in the Homochitto National Forest: a Geographic Information System Approach

Since the introduction of management practices by the Forest Service to stabilize red-cockaded woodpecker (RCW) populations, the number of cavity trees killed by southern pine beetles (SPB) has increased. A model of the landscape ecology of RCW and SPB in the Homochitto National Forest was created using data collected from the Forest Service and Global Atmospherics. The conclusions of the study were that the RCW and SPB utilize the same type of habitat and the stand hazard maps are an accurate means of determining the locations of SPB infestations. The functional heterogeneity maps created for the SPB and RCW would be useful predictors of future occurrences of either species if complete data were obtained.
Date: December 1998
Creator: Skordinski, Karen R. (Karen Renee)
System: The UNT Digital Library

General Biology Lecture and Laboratory Curriculum Outline in a Two or Four-Year College

Access: Use of this item is restricted to the UNT Community
In July of 1999, I wrote to 24 Texas junior and community colleges (and one four-year institution) describing my thesis agenda of a general biology lecture and laboratory syllabus for introductory biology students. I requested the titles and authors of the general biology textbooks and laboratory manuals they were currently using, the publishers of these texts, and the edition of said texts. I then contacted publishers of the various textbooks who, in turn, directed me to the Dallas-area representatives for further inquiries. I assimilated the various authors' general biology topics into a two-semester syllabus of lecture and one semester of laboratory. The document is not a text manuscript, but an all-inclusive listing of a general biology syllabus broken down by subject.
Date: August 2000
Creator: Moreland, Amy L.
System: The UNT Digital Library
Drumming Behavior of Selected North American Stoneflies (Plecoptera) (open access)

Drumming Behavior of Selected North American Stoneflies (Plecoptera)

Drumming is first described for five North American stonefly species, Acroneuria evoluta, Doroneuria baumanni, Isoperla namata, Chernokrilus misnomus, and Pictetiella expansa. Signals of Acroneuria lycorias, Phasganophora capitata and Isoperla signata are further described. Drumming was not recorded from Amhinemura delosa. Signals of A. evoluta are the most complex yet recorded in Plecoptera. Doroneuria baumanni, P. expanse, C. misnomus and P. capitata have 2-way exchanges. Male D. baumanni produce two prolonged beats by rubbing the hammer on the substratum; male-female signals are non-overlapping in the first two species and overlapping in the latter two. Female P. capitata answered with an unusually long sequence of beats. Two male Isoperla species produced monophasic calls without female answers. Female A. lycorias answered taped male signals with monophasic signals like all observed females.
Date: December 1983
Creator: Maketon, Monchan
System: The UNT Digital Library
Induction of Aryl Hydrocarbon Hydroxylase in Ambystoma tigrinum (open access)

Induction of Aryl Hydrocarbon Hydroxylase in Ambystoma tigrinum

Aryl hydrocarbon hydroxylase (AHH) was induced 15-fold in Ambystoma tigrinum by intraperitoneal injection of 3-methylcholanthrene in corn oil, or 10-fold by addition of aromatic polycyclic hydrocarbons to the aqueous environment of the neotene animal. The cytochrome P-450-associated microsomal enzyme is similar to the inducible, one-gene, autosomal-dominant system typical in the laboratory mouse and man. Differences in optimal temperature for enzyme induction and activity were noted in organ culture of human and Ambystoma tissues, and ratios of benzpyrene metabolites differed between Ambystoma and Mus. The half life of enzyme activity induced in vivo was related to the excretion of hydrocarbon metabolites.
Date: December 1974
Creator: Colvin, David P.
System: The UNT Digital Library

Temperature Change and Its Consequences for the Physiology of the Eurythermic Sheepshead Minnow (Cyprinodon variegatus)

The estuarine sheepshead minnow (Cyprinodon variegatus) is the most eurythermic fish species, with a thermal tolerance window between 0.6°C and 45.1°C. However, little is known about the physiological mechanisms that allow this species to survive this temperature range. In order to understand how sheepshead minnow physiology is affected by temperature acclimation and acute changes in temperature, I conducted research on this species using a multi-level approach. I began at the organismal level, and examined the effects of these temperature changes on the sheepshead minnow's metabolic rate and swimming performance. The next chapter investigated the effects of changing temperatures on cardiac function (i.e., tissue/organ specific effects). In the final chapter, I conducted research at the sub-cellular level, and determined how mitochondrial bioenergetics / function is impacted by changing temperatures. This research shows that while sheepshead minnows are able to sustain heart function and mitochondrial respiration over a broad range of temperatures; they also display a plastic temperature response which is associated with the downregulation of standard metabolic rate and cardiac remodeling to maintain force generation. Collectively, these physiological responses may contribute to the sheepshead minnow's ability to maintain physiological and organismal function across a large temperature range.
Date: August 2022
Creator: Reynolds, Amanda Caroline
System: The UNT Digital Library
Ethylbromo Acetate as an Olfactory Probe (open access)

Ethylbromo Acetate as an Olfactory Probe

Olfactory transduction mechanisms are best studied when specific blocking agents are available with which to modify cellular responses to odorant stimulation. This study is an electrophysiological investigation of functional group-specific olfactory acceptor mechanisms using ethylbromo acetate (EtBrAc), a World War I war gas which inhibits olfactory responses to odorant stimulation. The major findings of this investigation show that (1) vaporous EtBrAc is found to be a quick and effective inhibitor of electroolfactogram (EOG) responses to odorant stimulation, (2) isoamyl acetate is shown to protect EOG responses to a wide variety of odorants, inclusive of itself, from the inhibition effect of EtBrAc treatment, and (3) amine acceptor sites exist which are resistant to the inhibitory effects fo EtBrAc treatment.
Date: August 1980
Creator: McClure, Fred Leland
System: The UNT Digital Library
Effects of Phytohormones on Scenedesmus quadricauda (open access)

Effects of Phytohormones on Scenedesmus quadricauda

The literature on the effects of phytohormone on algae is clouded with contradictory reports. Reports have been published which substantiate and deny the effects of phytohormones in enhancing the growth and developmental processes in algae. The overall aim of this study was to investigate the response, if any, of the phytohormones indole-3-acetic acid (IAA), gibberellic acid A3 (GA) and kinetin on the physiology of the green alga, Scenedesmus quadricauda. Results obtained for the uptake of 14^C-IAA an(j l4C-kinetin by Scenedesmus strongly support the presumption that the alga does not absorb the hormones. The retention of the phytohormones by the alga is due to adsorption, and is independent of hormone concentration. Most of the label was adsorbed by the outer pectic layers of the cell wall.
Date: August 1977
Creator: Alam, Mohammad Ihtisham
System: The UNT Digital Library
Niche Expansion of an Invasive Predator (Neovison vison), Prey Response, and Facilitative Interactions with Other Invasive Mammals at the Southern End of the Americas: Conservation Challenges and Potential Solutions (open access)

Niche Expansion of an Invasive Predator (Neovison vison), Prey Response, and Facilitative Interactions with Other Invasive Mammals at the Southern End of the Americas: Conservation Challenges and Potential Solutions

The Cape Horn Biosphere Reserve is located at the southern tip of South America. This large archipelago is considered one of the last pristine areas left on the world. Despite it being an unpopulated area with most of the native forest cover intact, it has not been exempt from biological invasions, one of the major drivers of biodiversity loss. Three species that naturally interact in their native range in North America – American beavers (Castor canadensis), muskrats (Ondatra zibethicus), and American mink (Neovison vison) – were independently introduced in this remote region. In my dissertation, I investigated (i) the hypothesis of niche expansion in the invasive mink population on Navarino Island towards terrestrial habitats; (ii) potential mink impact on breeding success of forest-bird populations; (iii) habitat selection of small-rodent species and their perception on the mink's novel predation risk; and (iv) the dynamics of multiple-species invasions under the hypothesis of an invasional meltdown. Additionally, I worked within the framework of environmental philosophy. I provide an example of combining ecological and cultural dimensions within the International Long-Term Ecological Research network to disentangle the ethical dilemmas that surround the management of invasive species. I finally proposed a management plan based on the …
Date: December 2017
Creator: Crego, Ramiro Daniel
System: The UNT Digital Library

Animal Contribution to Human Medicine

Access: Use of this item is restricted to the UNT Community
The use of animal models in research has led to a fierce debate between animal rights activists and scientists. The former claim that little useful information is gained from animal studies and the suffering of animals does not preclude any treatments which may be used to treat human illnesses. Yet, research scientists claim that in vivo animal models are of absolute necessity to developing treatments and cures to disease. To determine the necessity of animal use, one must examine the models currently in research. Have the animal models for disorders such as cystic fibrosis and muscular dystrophy given scientists enough information to develop effective treatments? This paper will examine the role of animal subjects in several disease research protocols, as well as the applicability of the research.
Date: May 2001
Creator: Kvernes, Kayce
System: The UNT Digital Library
Photoreactivation Studies on Azotobacter vinelandii ATCC 12837 (open access)

Photoreactivation Studies on Azotobacter vinelandii ATCC 12837

This thesis was written to study photoreactivation in different physiological conditions of the vegetative cell as well as the photoreactivation of the two morphological states of the Azotobacter cell: the vegetative cell and the cyst.
Date: August 1968
Creator: Peterson, Johnny Wayne
System: The UNT Digital Library