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University of Nevada, Las Vegas

Theses/Dissertations

2014

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Environmental Protection And U.S. Foreign Policy & Decision-Making In Multilateral Development Banks, Maui Cheska L. Orozco Dec 2014

Environmental Protection And U.S. Foreign Policy & Decision-Making In Multilateral Development Banks, Maui Cheska L. Orozco

Honors College Theses

In recent decades, the promotion of policies that are environmentally friendly has become an important goal in U.S. foreign policy. One way that the United States has influence over protecting the environment is through the policies attached to projects funded by the multilateral development banks (MDBs). This gives the U.S. the ability to indirectly fund projects in developing countries. Using data provided by the United States Treasury, I examined U.S. voting decisions on projects from 2004 to 2011. These votes come from multiple development banks including the World Bank, the Inter-American Development Bank (IADB), Asian Development Bank (ADB), African Development …


An Assessment Of A 13-Week Teaching Gardens Intervention On Healthy Behavior Outcomes In 4th And 5th Grade Students At Crestwood Elementary School In Las Vegas, Nevada, Miranda Corgiat Dec 2014

An Assessment Of A 13-Week Teaching Gardens Intervention On Healthy Behavior Outcomes In 4th And 5th Grade Students At Crestwood Elementary School In Las Vegas, Nevada, Miranda Corgiat

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nearly 13 million children and adolescents are considered to be obese in the United States, with children enrolled in Clark County School District showing elevated overweight and obese weight statuses compared to national averages. Carrying an excessive amount of weight can lead children to experience a multitude of complications with their physical and mental health as well as increase their risk of developing various chronic diseases. The American Heart Association's Las Vegas Teaching Gardens program implemented a school-based garden pilot study to target environmental causes of obesity in 4th and 5th grade students at Crestwood Elementary School. The objective of …


Factors Associated With Rapid Readmission Among Nevada State Pyschiatric Hospital Patients, Christopher Owen Moore Dec 2014

Factors Associated With Rapid Readmission Among Nevada State Pyschiatric Hospital Patients, Christopher Owen Moore

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rapid readmission (RR) of psychiatric patients within 30 days of discharge places a costly burden on state psychiatric facilities and may be an indicator of suboptimal service provision. Several studies have previously considered RR to inpatient facilities, but there is a lack of information available about the variables associated with RR of psychiatric patients to state-operated inpatient facilities in Nevada. This study attempts to identify factors associated with RR at a southern Nevada state psychiatric hospital. Participants included 7,177 patients admitted between May 1, 2012 and April 30, 2014. All 12,068 admissions, including 2,220 RR, were reviewed, and rapid readmits …


A Survey Of Ekeland's Variational Principle And Related Theorems And Applications, Jessica Robinson Dec 2014

A Survey Of Ekeland's Variational Principle And Related Theorems And Applications, Jessica Robinson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ekeland's Variational Principle has been a key result used in various areas of analysis such as fixed point analysis, optimization, and optimal control theory. In this paper, the application of Ekeland's Variational Principle to Caristi's Fixed Point Theorem, Clarke's Fixed Point Theorem, and Takahashi's Minimization theorem is the focus. In addition, Ekeland produced a version of the classical Pontryagin Mini- mum Principle where his variational principle can be applied. A further look at this proof and discussion of his approach will be contrasted with the classical method of Pontryagin. With an understanding of how Ekeland's Variational Princple is used in …


Remote Sensing Based On Hyperspectral Data Analysis, Ershad Sharifahmadian Dec 2014

Remote Sensing Based On Hyperspectral Data Analysis, Ershad Sharifahmadian

UNLV Theses, Dissertations, Professional Papers, and Capstones

In remote sensing, accurate identification of far objects, especially concealed objects is difficult. In this study, to improve object detection from a distance, the hyperspecral imaging and wideband technology are employed with the emphasis on wideband radar. As the wideband data includes a broad range of frequencies, it can reveal information about both the surface of the object and its content. Two main contributions are made in this study:

1) Developing concept of return loss for target detection: Unlike typical radar detection methods which uses radar cross section to detect an object, it is possible to enhance the process of …


Estimating Aquifer Characteristics And Identification Of A Sub-Basin For Artificial Storage And Recovery, Northeastern Ivanpah Valley, Nevada, Nikolas James Taranik Dec 2014

Estimating Aquifer Characteristics And Identification Of A Sub-Basin For Artificial Storage And Recovery, Northeastern Ivanpah Valley, Nevada, Nikolas James Taranik

UNLV Theses, Dissertations, Professional Papers, and Capstones

The identification of a structurally controlled sub-basin with impediments to groundwater flow within Southern Nevada could provide a favorable area for artificial recharge and storage of native or imported water, extending the water supply of Southern Nevada. For this purpose, the area of northeastern Ivanpah Valley was investigated to determine the ability of the aquifer to accept and recover stored water, if acceptable water quality existed in the potential sub-basin storage area, and if structural controls impeded and isolated groundwater flow. The results found evidence the proposed sub-basin is structurally isolated by the McCullough, Roach, and Stateline Faults, which was …


Decontamination Protocols For Watercraft And Wildland Firefighting Equipment In Preventing The Spread Of Invasive Quagga (Dreissena Rostriformis Bugensis) And Zebra (Dreissena Polymorpha) Mussels, Ashlie Watters Dec 2014

Decontamination Protocols For Watercraft And Wildland Firefighting Equipment In Preventing The Spread Of Invasive Quagga (Dreissena Rostriformis Bugensis) And Zebra (Dreissena Polymorpha) Mussels, Ashlie Watters

UNLV Theses, Dissertations, Professional Papers, and Capstones

Quagga and zebra mussels (Dreissena rostriformis bugensis and Dreissena polymorpha) are two invasive species introduced via ballast water discharged by large oceanic cargo ships to the North American Great Lakes in the late 1980s. Once established, the mussels spread quickly. In January 2007, D. rostriformis bugensis was discovered in Lake Mead, NV-AZ, and in that same year, mussels were confirmed further south on the Colorado River in Lakes Mojave and Havasu. Dreissenids clog water intake pipes, water filtration systems, and electric generating plants. The mussels also ruin boat motors, damage recreational equipment, and once established in the reservoir, routine maintenance …


After Polarity: World Political Systems, Polar Structural Transitions, And Nonpolarity, Nerses Kopalyan Dec 2014

After Polarity: World Political Systems, Polar Structural Transitions, And Nonpolarity, Nerses Kopalyan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The research project poses the question: what are the polar structurations of a system after unipolar transitions, and should a system transition into a nonpolar structure, how can this phenomenon be explained? In the study of polarity, two deficiencies are diagnosed that can potentially not only fill a serious gap, but also strengthen the theoretical, conceptual, and systemic tools utilized within the field. The first gap is the absence of any developed treatments of nonpolarity. Categorical taxonomy primarily revolves around uni-, bi-, tri-, or multi- polar structures. The field lacks a coherent conceptualization of nonpolarity, thus limiting the development of …


Simulation, And Overload And Stability Analysis Of Continuous Time Sigma Delta Modulator, Kyung Kang Dec 2014

Simulation, And Overload And Stability Analysis Of Continuous Time Sigma Delta Modulator, Kyung Kang

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ever increasing demand for faster and more powerful digital applications requires high speed, high resolution ADCs. Currently, sigma delta modulators ADCs are extensively used in broadband telecommunication systems because they are an effective solution for high data-rate wireless communication systems that require low power consumption, high speed, high resolution, and large signal bandwidths.

Because mixed-signal integrated circuits such as Continuous Time sigma delta modulators contain both analog and digital circuits, mixed signal circuits are not as simple to model and simulate as all discrete or all analog systems. In this dissertation, the delta transform is used to simulate CT …


Alcohol And Drug Use Amongst College Students In Relation To Sexual Abuse, Christyn Hollingsworth Dec 2014

Alcohol And Drug Use Amongst College Students In Relation To Sexual Abuse, Christyn Hollingsworth

Honors College Theses

The impact of child sexual abuse (CSA) and traumatic sexual experiences has been the subject of multiple studies in which harm was found. Among these harms are emotional distress, psychological issues, and substance abuse. This research analyzed and compared the responses to questions pertaining to substance use and attitudes regarding sexual interactions between college aged students with and without a history of sexual abuse. The participant’s answers were run through an ANOVA to determine statistical variance. Based on prior research, it was expected that victims consume alcohol and use drugs more frequently than non-victims in significant amounts. The findings in …


A Narrative Study Of Male Accompanying Partners: Adaptation To A Nontraditional Role In Dyadic Partnerships, Donald J. Bernard Dec 2014

A Narrative Study Of Male Accompanying Partners: Adaptation To A Nontraditional Role In Dyadic Partnerships, Donald J. Bernard

UNLV Theses, Dissertations, Professional Papers, and Capstones

Although the traditional conceptual paradigm of an accompanying spouse, sometimes referred to in social science literature as a trailing partner, emanates from a predominantly female perspective, an emerging trend involves men functioning in that role. With America's changing workforce due to the increased labor force participation of women, a postmodern family structure has emerged as the role of men as breadwinners-in-chief in the traditional nuclear family has been steadily eroded. The academic literature on the traditional pattern of wives trailing their husbands to new geographical for better employment and income is voluminous. However, studies on the emergence of males accompanying …


Simultaneous Determination Of Multiple Actinide Elements In A Variety Of Soils Utilizing A Standardized Sequential Extraction Protocol, Sherry Alina Faye Dec 2014

Simultaneous Determination Of Multiple Actinide Elements In A Variety Of Soils Utilizing A Standardized Sequential Extraction Protocol, Sherry Alina Faye

UNLV Theses, Dissertations, Professional Papers, and Capstones

To obtain a better understanding of the mobility of actinide element contaminants in the environment, the association of the contaminants with specific host phases of soils and sediments must be investigated. This investigation is most commonly conducted using sequential extraction techniques that employ the selective dissolution of soil phases with increasingly aggressive chemical treatment. Though several sequential extraction studies exist in literature, conclusions cannot be made by direct comparison of data due to the lack of uniformity in the protocols used. This work aims to continue development of a standard sequential extraction protocol and expanding its capabilities to include the …


Technetium Sulfide: Fundamental Chemistry For Waste Storage Form's Application, Maryline Ghislaine Ferrier Dec 2014

Technetium Sulfide: Fundamental Chemistry For Waste Storage Form's Application, Maryline Ghislaine Ferrier

UNLV Theses, Dissertations, Professional Papers, and Capstones

Technetium is the lightest radioelement. The isotope 99Tc has around a 6% yield from 235U with a half-life of 2.13 x 105 years. The high mobility of TcO4-, the common chemical form of technetium in the environment makes 99Tc an isotope of concern in nuclear waste management. Despite its important role in radiopharmaceuticals and in the nuclear fuel cycle, the fundamental chemistry of technetium is not as well developed as that of the neighboring transition metals; one of the most striking examples being its sulfide chemistry.

Only two technetium binary sulfide compounds had …


Concurrent Localized Wait-Free Operations On A Red Black Tree, Vitaliy Kubushyn Dec 2014

Concurrent Localized Wait-Free Operations On A Red Black Tree, Vitaliy Kubushyn

UNLV Theses, Dissertations, Professional Papers, and Capstones

A red-black tree is a type of self-balancing binary search tree. Some wait-free algorithms have been proposed for concurrently accessing and modifying a red-black tree from multiple threads in shared memory systems. Most algorithms presented utilize the concept of a "window", and are entirely top-down implementations. Top-down algorithms like these have to operate on large portions of the tree, and operations on nodes that would otherwise not overlap at all still have to compete with and help one another.

A wait-free framework is proposed for obtaining ownership of small portions of the tree at a time in a bottom-up manner. …


A Study Of Graphical Permutations, Jessica Thune Dec 2014

A Study Of Graphical Permutations, Jessica Thune

UNLV Theses, Dissertations, Professional Papers, and Capstones

A permutation π on a set of positive integers {a_1,a_2,...,a_n} is said to be graphical if there exists a graph containing exactly a_i vertices of degree (a_i) for each i. It has been shown that for positive integers with a_1


Impact Of A Grade Contract Model In A College Composition Course: A Multiple Case Study, Nayelee Villanueva Dec 2014

Impact Of A Grade Contract Model In A College Composition Course: A Multiple Case Study, Nayelee Villanueva

UNLV Theses, Dissertations, Professional Papers, and Capstones

Due to the complex nature of assessment in critical pedagogy practices, continued research is necessary in order to investigate the constantly evolving nature of education and the way we come to know how people learn. To research assessment in the critical classroom requires both instructor and students. This qualitative multiple case study investigated impacts of a grading contract as a form of assessment on student writing in a Basic Writing composition course. This study examined the impacts of a grade contract on students' writing, motivation for writing, revision practices, authorship and expectations of a Basic Writing composition course. Through a …


Exact Controllability Of The Lazer-Mckenna Suspension Bridge Equation, Lanxuan Yu Dec 2014

Exact Controllability Of The Lazer-Mckenna Suspension Bridge Equation, Lanxuan Yu

UNLV Theses, Dissertations, Professional Papers, and Capstones

It is well known that suspension bridges may display certain oscillations under external aerodynamic forces. Since the collapse of the Tacoma Narrows suspension bridge in 1940, suspension bridge models have been studied by many researchers. Based upon the fundamental nonlinearity in suspension bridges that the stays connecting the supporting cables and the roadbed resist expansion, but do not resist compression, new models describing oscillations in suspension bridges have been developed by Lazer and McKenna [Lazer and McKenna (1990)]. Except for a paper by Leiva [Leiva (2005)], there have been very few work on controls of the Lazer-McKenna suspension bridge models …


Gis Framework For Spatiotemporal Mapping Of Urban Flooding And Analyze Watershed Hydrological Response To Land Cover Change, Sayed Joinal Hossain Abedin Dec 2014

Gis Framework For Spatiotemporal Mapping Of Urban Flooding And Analyze Watershed Hydrological Response To Land Cover Change, Sayed Joinal Hossain Abedin

UNLV Theses, Dissertations, Professional Papers, and Capstones

Urban flooding is a manmade disaster, and a recurrent problem in cities around the globe. Increased surface imperviousness due to urbanization along with inadequate drainage infrastructure system are the chief culprits for urban flooding. Flooding in an urban area brings about severe economic, structural, and environmental damages, and can be associated with casualties too. In order to evade flooding, an efficient flood model is imperative to study current flooding, and analyze flooding behavior to urban surface characteristics.

This research aims to develop a framework using Geographic Information System (GIS) to perform modeling and mapping of flood spatiotemporal variation in urban …


Morphometric Assessment Of The Internal Auditory Canal For Sex Determination In Subadults Using Cone Beam Computed Tomography (Cbct), Saoly Benson Dec 2014

Morphometric Assessment Of The Internal Auditory Canal For Sex Determination In Subadults Using Cone Beam Computed Tomography (Cbct), Saoly Benson

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study reports on the use of three methods for sex determination in subadults using the petrous portion of the temporal bone. The purpose of this study was to validate and refine two previously published methods of sex determination for the internal auditory canal as well as to develop a novel method. The sample was comprised of 276 cone beam computed tomography (CBCT) scans of a population of subadults age 6-24 (165 females, 111 males) divided into 5 age groups for analysis: Group 1 (age 6-10), Group 2 (age 11-13), Group 3 (age 14-16), Group 4 (age 17-19), and Group …


Listening To The Ranks: Perceptions Of The U.S. Air Force Occupational Health And Safety Training, Melissa Jo Breunig Dec 2014

Listening To The Ranks: Perceptions Of The U.S. Air Force Occupational Health And Safety Training, Melissa Jo Breunig

UNLV Theses, Dissertations, Professional Papers, and Capstones

Occupational health and safety hazards are abundant in military environments. Due to the hazardous occupational settings, injuries remain a public health concern in the United States military. Public health plays a critical role in injury reduction by addressing the need for comprehensive safety education training, and more specifically, exposure related injuries. A secondary data analysis was completed using Communication Theory as the overarching framework to analyze 13 qualitative interviews conducted with Airmen to gain their perceptions of the occupational health and safety training at Nellis and Creech Air Force Base (AFB). Pedagogy and training content were the two main themes …


Characteristics Of Unintentional Prescription Drug Poisoning Admissions Clark County, Nevada 2009-2013, Tamara Bruno Dec 2014

Characteristics Of Unintentional Prescription Drug Poisoning Admissions Clark County, Nevada 2009-2013, Tamara Bruno

UNLV Theses, Dissertations, Professional Papers, and Capstones

Prescription drug abuse has been the fastest growing drug problem in the United States in recent years, and is the second most commonly abused category of illegal and illicit drugs, after marijuana (SAMHSA, 2013; Carnevale, 2011). Reducing the morbidity and mortality associated with prescription drug abuse in challenging because multiple factors contribute to the problem. Prescribing behaviors and the lack of education among providers and pharmacists along with inadequate counseling and

monitoring of patients prescribed pain medication are important factors (Machikanti, 2007; Okie, 2010). Patients' misuse or abuse, diversion or the sharing or sell of pills, and doctor shopping are …


Understanding Brand Authenticity In Specialized Communities: An Interpretive Qualitative Study Of The Brit Iron Rebels Las Vegas Clan, Sullivan Charles Dec 2014

Understanding Brand Authenticity In Specialized Communities: An Interpretive Qualitative Study Of The Brit Iron Rebels Las Vegas Clan, Sullivan Charles

UNLV Theses, Dissertations, Professional Papers, and Capstones

Postmodern society is marked by a condition where traditional identity markers have degenerated in value. Without the spatial or temporal connection provided by traditional identity markers, individuals look to brands perceived to be authentic to aide in identity construction. Paradoxically, individualized identities need the interpretive support of other likeminded individuals in specialized communities to give legitimacy to constructed identities. These specialized communities often focus around a lifestyle or a brand. This research employed interpretive qualitative methodology to understand authenticity. Semistructured depth interviews were conducted with members of the Brit Iron Rebels Las Vegas Clan to understand the authenticity of Triumph …


Investigation Of Chloride Induced Corrosion Of Bridge Pier And Life-Cycle Repair Cost Analysis Using Fiber Reinforced Polymer Composites, Dinesh Dhakal Dec 2014

Investigation Of Chloride Induced Corrosion Of Bridge Pier And Life-Cycle Repair Cost Analysis Using Fiber Reinforced Polymer Composites, Dinesh Dhakal

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bridges are the long term investment of the highway agencies. To maintain the required service level throughout the life of a bridge, a series of maintenance, repair, and rehabilitation (MR&R) works can be performed. To investigate the corrosion deterioration and maintenance and repair practices in the bridge pier columns constructed in chloride-laden environment, a questionnaire survey was conducted within the 50 state Departments of Transportation (DOTs). Based on the survey data, two corrosion deterioration phases were identified. They were corrosion crack initiation phase and corrosion propagation phase. The data showed that the mean corrosion crack initiation phase for bridge pier …


Lung Cancer Survival Disparities In Nevada, Chima Osuoha Dec 2014

Lung Cancer Survival Disparities In Nevada, Chima Osuoha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lung cancer is the leading cause of cancer death in both men and women in the United States. Nevada shows moderate incidence rates of lung cancer for men but high rates for women. Little is known about the lung cancer experience and survival characteristics of the nearly 2000 new cases occurring every year in the State. The purpose of this study was to measure the extent to which geographic area of residency, gender, race, health insurance, social economic status (SES) and stage at diagnosis were associated with survival in patients diagnosed with lung cancer in Nevada. This was a retrospective …


Subalklaine Volcanism In The Eastern Basin And Range Province: Examples From The Miocene Mccullough Range Volcanic Field And The Pliocene To Holocene Black Rock Desert Volcanic Field, Racheal Leighann Johnsen Dec 2014

Subalklaine Volcanism In The Eastern Basin And Range Province: Examples From The Miocene Mccullough Range Volcanic Field And The Pliocene To Holocene Black Rock Desert Volcanic Field, Racheal Leighann Johnsen

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation is composed of three papers that apply geologic mapping, whole rock geochemical and isotopic analysis, and mineral chemistry to describe two large, long-lived (~6 million years), and compositionally heterogeneous volcanic fields and posit sources of the rock types present in each. These fields are the McCullough Range in southern Nevada, which was a locus of volcanic activity from ~19 - 12 Ma and the Black Rock Desert volcanic field in west-central Utah, which began forming at ~6 Ma and is still active today, with the most recent eruption occurring ~720 years ago.

Chapter Two is composed of a …


Possible Benefits Of Playing Music Video Games, Amanda Pasinski Dec 2014

Possible Benefits Of Playing Music Video Games, Amanda Pasinski

UNLV Theses, Dissertations, Professional Papers, and Capstones

Music video games, such as Rock Band, are an emerging and popular genre of video game that allows non-musicians a taste of what it is like to be a musician. For most people, developing musicianship (or the process of becoming competent with a particular musical instrument) to an expert level is a long and difficult process that can take up to 10 years or over 7,500 hours to complete. Yet musicians tend to outperform non-musicians on a variety of tasks--showing greater motor coordination, better synchronization skills, and better pitch and tempo discrimination--and possibly show differences in related cognitive processes. However, …


Digital Behavior Intervention Plans: Effects On General Education Teacher Fidelity Of Implementation, Christopher G. Holcomb Dec 2014

Digital Behavior Intervention Plans: Effects On General Education Teacher Fidelity Of Implementation, Christopher G. Holcomb

UNLV Theses, Dissertations, Professional Papers, and Capstones

Students with disabilities often have behavior that interferes with classroom learning. Serious problem behaviors are identified as the most significant factor interfering with learning in the classroom. Unfortunately, chronic behaviors often lead to a student dropping out of school. Current research typically focuses on areas of intervention for these students with little attention towards teacher fidelity of implementation of these interventions. Because of this, student's behavior intervention plans may not show effectiveness (e.g., progress monitoring, data driven decisions). It is important that researchers begin to explore systematic improvements in fidelity of implementation of behavior intervention plan components for general education …


Factor Structure Of The Cpt-Ii, Mary Vertinski Dec 2014

Factor Structure Of The Cpt-Ii, Mary Vertinski

UNLV Theses, Dissertations, Professional Papers, and Capstones

The current study investigates the factor structure of the Conners' Continuous Performance Test-II (CPT-II) in four pediatric samples of participants: (a) patients with traumatic brain injury, (b) healthy controls, (c) patients with various clinical diagnoses, and (d) all of the previously mentioned subjects combined. Confirmatory factor analyses (CFA) were used to investigate a one-, three- and four-factor model fit of the data. None of the models examined were an adequate fit for the data; however, it appears that the four-factor model seemed to be the best fitting of the models examined. Failure to find reasonably adequate fit precluded further analyses.


Jack Kerouac's Artistic Apprenticeship And The Discovery Of His Authentic Voice, Nathaniel Botsis Dec 2014

Jack Kerouac's Artistic Apprenticeship And The Discovery Of His Authentic Voice, Nathaniel Botsis

UNLV Theses, Dissertations, Professional Papers, and Capstones

Few novels so clearly dramatize an artist's discovery of his authentic voice as does Kerouac's On the Road. The publication of the writing that Kerouac did before On the Road, and particularly the writing he did before The Town and the City, offers almost unprecedented opportunity to study his artistic apprenticeship and trace his development as an artist. To study Kerouac's apprenticeship is to witness him learning how to liberate himself in order to be that which he would become. In addition to shedding light on this unexamined aspect of Kerouac's career, I hope this study might inspire similar breakthroughs …


New Early Miocene 40ar/39ar Ages For Nakwai, Northwest Kenya, Africa, And Paleontological Analysis Of Meroehyrax Kyongoi Dentition, Dawn Elena Reynoso Dec 2014

New Early Miocene 40ar/39ar Ages For Nakwai, Northwest Kenya, Africa, And Paleontological Analysis Of Meroehyrax Kyongoi Dentition, Dawn Elena Reynoso

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nakwai is a fossiliferous region in the Turkana Basin of northwestern Kenya. Until recently the only ages for the Nakwai formation were based on biostratigraphic correlation with Losodok; a late Oligocene site located to the north of Nakwai. The new 40Ar/39Ar ages in this study range from 23 Ma to 15 Ma and constrain the upper portions of the Nakwai section to the early Miocene. These ages make it the only securely dated fossil locality in the region that represents the earliest Miocene; all of the other early Miocene fossil localities date back to ~20 Ma or younger. The time …