Defining functional tooth morphotypes in extant and extinct crocodylians, with dietary and feeding implications

Thesis (M.S.)--University of Oklahoma, 2000.Includes bibliographical references (leaves 33-42).Crocodylians have traditionally been considered to have homodont dentitions (eg., Kalin, 1933; Langston, 1973). Although all the teeth in these species are cone-shaped, there is a large amount of morphological variation present, which has prompted some authors to describe crocodylian dentitions as heterodont (eg., Kieser et al., 1993; Aoki, 1989). Furthering such observations, ten modern crocodylian species were sampled and their teeth measured in four aspects. These data were processed using principal components and cluster analyses, and functional tooth morphs were defined within each species. Tooth morphs (here termed "functional morphotypes") were then correlated with dietary and feeding information gleaned from other studies. An ontogenetic series of Alligator mississippiensis skulls was used to test for ontogenetic changes in the dentition. While many have reported that crocodylian teeth change shape ontogenetically (eg., Langston, 1973; Westergaard, 1990), no significant ontogenetic changes in tooth shape were found to occur. This finding lends greater importance to all research concerning crocodylian tooth morphology. Finally, a random sample of Cretaceous age crocodyliform teeth from the Cedar Mountain Formation in Utah (OMNH site V695) was tested using the preceding methodology to discover the number of tooth morphotypes and species present in this sample. Based on the large number of morphotypes defined, at least three species are represented. The low degree of clarity gleaned from this part of the study, however, urges caution in applying generic and family-level designations to isolated fossilized teeth. Moreover, the high degree of heterodonty present in fossil taxa suggests that only the most conservative identifications be attempted until more is known about the dentitions of fossil crocodyliform taxa

Volatile organic compound and methane emissions from well development operations in the Piceance Basin

Includes bibliographical references.2016 Summer.The natural gas industry in Colorado has experienced significant growth in the last decade due to widespread use of unconventional natural gas extraction technologies. Garfield County is located in the Rocky Mountain Region on the western slope of Colorado above the Piceance Basin. Natural gas wells in this region penetrate the William’s Fork formation, located approximately 4,000 ft. below the surface, which is a tight sand formation known to be rich in natural gas. Horizontal drilling increases the extraction potential of natural gas stored in several sandstone lenses. Hydraulic fracturing is a stimulation technique used to maximize the flow and efficiency of natural gas transport to the surface from unconventional reservoirs. Once the formation is adequately cracked, 10-50% of the hydraulic fluid flows back to the surface . Our field team collected samples in Garfield County between 2013-2015 to measure methane, ozone precursors, and air toxics associated with natural gas extraction activities. Very few studies have provided direct observations of VOC emissions from individual well development activities. Emission rates of 48 VOCs and methane were determined using the tracer ratio method for three well development operations: drilling, hydraulic fracturing (fracking), and flowback for a subset of samples collected. Methane had mean emission rates of 1.57, 6.78, and 25.6 g s-1 for drilling, hydraulic fracturing, and flowback operations respectively, while toluene had mean emission rates of 1.24, 0.469, and 0.437 g s-1 for these operations. Measured emission rates were used to determine if specific VOCs were well correlated with each other and/or methane emission rates. Strong correlations between individual VOC emission rates and methane were investigated to assess whether methane emission rates might serve as useful surrogates for emission rates of individual VOCs, which are less easily measured. We found that methane and ethane appear to be emitted from the same sources for all operation types indicating that methane emission rates may be useful surrogates for ethane emission rates. Methane emission rates appear not to be very useful surrogates for heavier VOCs, including C5-C10 alkanes, alkenes, and aromatics. Concentration ratios of source-specific tracer compounds were investigated to determine the source signatures of individual operation types. We found that drilling emissions appear to be primarily influenced by combustion, while flowback emissions are primarily influenced by the release of natural gas and other substances from the well

The effectiveness of the Ohio state, the ACE, and the Cooperative English tests in predicting the scholastic success of college freshmen

Thesis (M.A.)--Boston University, 1948. This item was digitized by the Internet Archive

Strategies for ensuring sustainable democracy in South Africa

This article examines the South African experience of democracy and focuses in particular on the democratisation of South Africa’s government and administration. The democratisation process has not been problem-free. The tone was set by the negotiation of the 1993 Interim Constitution Act, and later the promulgation of a 1996 Constitution Act. Both these Constitution Acts made provision for a host of human rights and for a democratic dispensation intended to function in a multiparty context. To promote sustainable democracy, and to ensure that the majority of constitutional principles are upheld as far as possible, various checks and balances have to be built into the South African governmental system. It is essential that all public functionaries be accountable for their actions and/or lack thereof. This article examines some of the mechanisms or strategies to keep democracy vibrant and to ensure that public functionaries serve the general good, and do not pursue selfish, parochial interests

A New Day for Nuclear: The Impact of Nuclear Energy and Its Effects

Energy is a resource on which civil society is built. It affects every aspect of life and is vital to the survival of the modern world. This paper explores nuclear power and the effects it has on a national and global scale. The research looks at both the positive and negative aspects of nuclear energy, giving weight to both sides of the argument to present a detailed look at this resource. The research is compiled from a wide range of authors from scientists and nuclear experts to reporters and strategic intelligence agents. A proposed technology for the advancement of nuclear energy is also examined to show its benefits and compare it to conventional nuclear energy. This paper will assist any concerned citizen in making an informed decision on the world’s most vital resource, energy

A Flow Cytometric Assay for the Study of E3 Ubiquitin Ligase Activityb

This is the peer reviewed version of the following article: Hilliard, J. G., Cooper, A. L., Slusser, J. G. and Davido, D. J. (2009), A flow cytometric assay for the study of E3 ubiquitin ligase activity. Cytometry, 75A: 634–641. doi:10.1002/cyto.a.20738, which has been published in final form at http://doi.org/10.1002/cyto.a.20738. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.BACKGROUND: Current methods for monitoring E3 ubiquitin ligase activity in cell culture or in vivo are limited. As a result, the degradation of cellular targets by many E3 ubiquitin ligases in live cells has not yet been examined. METHODS: A target of an E3 ubiquitin ligase was expressed as a fluorescently labeled protein in cell culture. If the E3 ubiquitin ligase mediates the degradation of a target protein in cell culture, it is expected that the target will show a reduced fluorescence signal by FCM analysis. We initially used the E3 ubiquitin ligase, herpes simplex virus type 1 (HSV-1) infected cell protein 0 (ICP0) and one of its targets, promyelocytic leukemia (PML) protein, to determine the feasibility of our approach. Cells expressing a PML-GFP fusion protein were selected by cell sorting and infected with an adenoviral vector expressing ICP0. RESULTS: In contrast to mock-infected cells, only PML-GFP-expressing cells infected with the ICP0 adenoviral vector led to a significant decrease in the fluorescence signal of PML-GFP when examined by fluorescence microscopy and FCM analysis. CONCLUSIONS: Using HSV-1 ICP0 as a paradigm, it is possible to examine the live activity of an E3 ubiquitin ligase (via one of its targets) in cell culture with FCM analysis

Evaluation of the Effects of Sativex (THC BDS: CBD BDS) on Inhibition of Spasticity in a Chronic Relapsing Experimental Allergic Autoimmune Encephalomyelitis: A Model of Multiple Sclerosis.

This study investigated the antispasticity potential of Sativex in mice. Chronic relapsing experimental allergic encephalomyelitis was induced in adult ABH mice resulting in hind limb spasticity development. Vehicle, Sativex, and baclofen (as a positive control) were injected intravenously and the "stiffness" of limbs assessed by the resistance force against hind limb flexion. Vehicle alone caused no significant change in spasticity. Baclofen (5 mg/kg) induced approximately a 40% peak reduction in spasticity. Sativex dose dependently reduced spasticity; 5 mg/kg THC + 5 mg/kg CBD induced approximately a 20% peak reduction; 10 mg/kg THC + 10 mg/kg CBD produced approximately a 40% peak reduction in spasticity. Sativex has the potential to reduce spasticity in an experimental mouse model of multiple sclerosis (MS). Baclofen reduced spasticity and served as a positive control. Sativex (10 mg/kg) was just as effective as baclofen, providing supportive evidence for Sativex use in the treatment of spasticity in MS

Strategies for ensuring sustainable democracy in South Africa

This article examines the South African experience of democracy and focuses in particular on the democratisation of South Africa’s government and administration. The democratisation process has not been problem-free. The tone was set by the negotiation of the 1993 Interim Constitution Act, and later the promulgation of a 1996 Constitution Act. Both these Constitution Acts made provision for a host of human rights and for a democratic dispensation intended to function in a multiparty context. To promote sustainable democracy, and to ensure that the majority of constitutional principles are upheld as far as possible, various checks and balances have to be built into the South African governmental system. It is essential that all public functionaries be accountable for their actions and/or lack thereof. This article examines some of the mechanisms or strategies to keep democracy vibrant and to ensure that public functionaries serve the general good, and do not pursue selfish, parochial interests