Digital Commons Network^™

Reflections Of An Early Literacy Professional Learning Community: An Interactional Ethnographic Case Study Of Transforming Pedagogy Through Reflective Practice, Carly Waters

UNLV Theses, Dissertations, Professional Papers, and Capstones

Teachers have historically been faced with extrinsic factors, such as federal, state, and local mandates, that leave them feeling disempowered (Slattery, 2006; Spring 2018). In response to low reading proficiency, many states have adopted Read by Grade Three laws, some of which require or make optional retention of students that are not reading proficiently by the end of third grade. Laws such as these, though well-intentioned, provide another external force that leave teachers feeling stressed and chained to practices they are told to implement. Effective professional development that targets both strong early literacy pedagogy and the empowerment of teachers may …

An Evaluation Of Bank Storage At Lake Mead Reservoir In The Southwest United States, Jon Woodrow Wilson

UNLV Theses, Dissertations, Professional Papers, and Capstones

A water balance model is employed at Lake Mead to monitor and verify changing hydrology that affects total volume at the reservoir. Bank storage, which is defined as the volume of water captured in permeable lithologic layers subject to changes induced by contact and proximity to an open waterbody, is one component that is updated regularly and is based upon data and methods that were developed in the 1960’s from observations made within the first 30 years of the reservoir's maturation. Since this period, the reservoir has undergone further development and a current understanding of additional hydrologic affects to bank …

Motivational Predictors Of Academic Risk-Taking, Danette Dee Barber

UNLV Theses, Dissertations, Professional Papers, and Capstones

Students benefit when they are willing to engage in optimal challenges (Clifford, 1991). Engagement in challenges, however, comes with academic risks, as failure may be a result. This study investigated motivational factors, including expectancy, subjective task value, mastery goal orientation, and performance avoidance goal orientation as predictors of achievement-related outcomes, including course grade and academic risk-taking. Data were collected from 317 university students enrolled in education classes. Students were given a reading passage and asked to choose questions to answer based on the passage. Students who chose harder questions were categorized as taking more risk. Students also answered questions about …

An Investigation Of White-Collar Criminal Sentencing Disparities In Six Federal District Courts, Lauren Frances Elizabeth Galloway

UNLV Theses, Dissertations, Professional Papers, and Capstones

Since the turn of the century, sentencing research has consistently shown that certain aspects of the social context generally condition individual-level sentencing variations. I further explore this postulation in assessing how legal changes affect courtroom decisions; and in analyzing how extra-legal offender characteristics and judicial attributes influence the likelihood and length of white-collar incarceration sentences. The study hypothesized an emergent sociotemporal trend, largely driven by implementation of white-collar sentencing legislation and a return to judicial discretion, whereby white-collar offenders sentenced in the years post-Booker would receive more lenient punishments (i.e., less likely to be incarcerated and shorter incarceration sentences) than …

Machine Learning Approach For Predicting Cancer Using Gene Expression, Aashi Maharjan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cancer has become one of the major factors responsible for global deaths, due to late diagnoses and lack of proper treatment. It involves the abnormal and uncontrolled growth of cells inside the body, which might spread from one place to different parts. Ribonucleic acid (RNA) sequencing can detect the changes occurring inside cells and helps to analyze the transcriptome of gene expression patterns inside RNA. Machine learning techniques can assist in the prediction of cancer at an early stage, if data is available. The objective of this thesis is to build models and classify different types of cancer. For this …

Studies On Kernels Of Simple Polygons, Jason Mark

UNLV Theses, Dissertations, Professional Papers, and Capstones

The kernel of a simple polygon is the set of points in its interior from which all points inside the polygon are visible. We formally establish that for a given convex polygon Q we can always construct a larger simple polygon with many reflex vertices such that Q is the kernel of P. We present algorithms for decomposing a strongly monotone polygon into star-polygons. This decomposition is applied for developing an efficient algorithm for placing a small number of vertical towers to cover the entire given 1.5D terrain. We also present an experimental investigation of the proposed algorithm. The implementation …

Towards Multi-Modal Data Classification, Henry Ng

UNLV Theses, Dissertations, Professional Papers, and Capstones

A feature fusion multi-modal neural network (MMN) is a network that combines different modalities at the feature level to perform a specific task. In this paper, we study the problem of training the fusion procedure for MMN. A recent study has found that training a multi-modal network that incorporates late fusion produces a network that has not learned the proper parameters for feature extraction. These late fusion models perform very well during training but fall short to its single modality counterpart when testing. We hypothesize that jointly trained MMN have weight space that is too large for effective training. To …

Examining Grit With Middle Schoolers In Diverse General Education Classrooms – Validating The Grit Scale, Cristina Liliana Reding

UNLV Theses, Dissertations, Professional Papers, and Capstones

Educators and researchers are still attempting to narrow the achievement gap for students in diverse needs general education classrooms. In this quest, non-cognitive skills are being researched for their potential to influence behavioral changes and to increase the academic success of diverse needs students. Grit, a newly defined non-cognitive skill, is defined as perseverance and passion for long term goals. This construct has been explored in a variety of settings but not in diverse general education classrooms, with participants from culturally, linguistically and ability diverse groups. The validity of instruments is paramount for successful studies, and current scales measuring non-cognitive …

Infiltration Into Water-Repellent Sand: The Role Of Sorptivity, Rose Marie Shillito

UNLV Theses, Dissertations, Professional Papers, and Capstones

Soil water repellency (SWR) is believed to contribute to the increased potential for post-fire runoff and erosion. Currently, no quantitative method exists to account for SWR in physically-based runoff models. A physically-based model incorporating SWR (through the contact angle) in the infiltration parameter, sorptivity, was developed. The model was tested and verified with controlled laboratory tests on a fully characterized sand treated to create various degrees of SWR. The ability to create the wetting water characteristic curve for untreated and treated sand, appropriate for the infiltration process, was presented. Additionally, the ability to measure sorptivity with widely used infiltration tests …

Paleoecology Of Columbian And Pygmy Mammoths In Southern Nevada And California: How Terminal Pleistocene Ecosystems Shaped Mammoths At The Individual, Population, And Community Level, Lauren Elizabeth Parry

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this dissertation research is to examine the paleoecology of the Columbian mammoth (Mammuthus columbi) and the pygmy mammoth (M. exilis) on the individual, population, and community level, emphasizing factors internal to their ecosystem that may have contributed to their extinction. I focus specifically on mammoths from Southern Nevada and Southern California to add regional data to the complex and evolving study of North American mammoth paleoecology.

Chapter 2 documents the permitted excavation of a partial mammoth (Mammuthus sp.) between 2016-2018 from late Pleistocene groundwater-discharge deposits near Fairbanks Spring in the Amargosa Valley, Nevada. A preliminary radiocarbon date …

Detection Of Snps Associated With Bone Loss Rate By Using Machine Learning Approaches, Avinash Yaganapu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Osteoporosis is one of the most common diseases seen in postmenopausal women, it decreases the bone density and quality, and later causes bone loss. Generally, bone loss occurs when bone losses its content and become porous: a sponge like substance. In most Genome Wide Association Studies (GWAS), researchers perform experiments with genomic data that contains some millions of numbers of single nucleotide polymorphisms (SNPs) and checks their association with the trait or disease. In this thesis, we performed two separate analyses with 2207 (of bone loss and bone gain) and 645 (of bone loss) instances separately. For predicting the SNPs …

Machine Learning For Prediction Of Trabecular And Cortical Bone Mineral Density, Partha Chudal

UNLV Theses, Dissertations, Professional Papers, and Capstones

Osteoporosis becomes very common problem for people after a certain age, which results in fragility fractures without any previous symptoms. One of the primary predictors of osteoporosis is bone mineral density (BMD). BMD is the mineral content of bone, at the optimal levels, that makes the bone strong enough to bear the regular load and elastic enough to handle the irregular twisting load. Two of the major parts of the bone that help to acquire such property are trabecular and cortical bone. This thesis focuses on predicting the BMDs of trabecular and cortical bone for men. For this purpose we …

The Relationship Between Tree Canopy And Social Capital On Physical Activity In Unlv Students, Melissa Bartshe

UNLV Theses, Dissertations, Professional Papers, and Capstones

Despite the numerous health benefits, rates of physical activity are low, especially among the college student population. Neighborhood tree canopy is one aspect of the built environment that has been shown to positively impact physical activity. Social capital has also been correlated with higher rates of physical activity. The sprawling urban design and arid desert climate of Las Vegas pose unique challenges to both tree canopy and social capital. Additionally, the relationship between tree canopy, social capital, and physical activity is understudied in the college student population. The purpose of this study was to assess the relationship of tree canopy …

Abiotic, Biotic, And Bio-Enhanced Reduction Of Hexavalent Chromium, Chloroform And Co-Contaminants Using Nano-Scale Zero Valent Iron In Highly Contaminated Groundwater, Eduardo Robleto Martinez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Investigations of groundwater in a former industrial perchlorate manufacturing site have shown high contamination with perchlorate, chlorate, nitrate, hexavalent chromium (Cr (VI)), and chloroform (CF) with levels greater than 3,000, 30,000, 300, 100, and 4 mg/L, respectively. Remediation efforts using biological reduction to desired contaminant levels at this site has been challenging due to high contaminant concentrations, and high total dissolved solids (TDS). Furthermore, removal of Cr(VI) and CF in the presence of nitrate, chlorate, and perchlorate has not been examined at the contaminated site. Nano-scale Zero-Valent-Iron (NZVI) has been effective at reducing groundwater contamination both with and without bacterial …

Accurate Confidence Intervals For Risk Difference In Meta-Analysis With Rare Events, Tao Jiang, Baixin Cao, Guogen Shan

Environmental & Global Health Faculty Research

Background: Meta-analysis provides a useful statistical tool to effectively estimate treatment effect from multiple studies. When the outcome is binary and it is rare (e.g., safety data in clinical trials), the traditionally used methods may have unsatisfactory performance. Methods: We propose using importance sampling to compute confidence intervals for risk difference in meta-analysis with rare events. The proposed intervals are not exact, but they often have the coverage probabilities close to the nominal level. We compare the proposed accurate intervals with the existing intervals from the fixed- or random-effects models and the interval by Tian et al. (2009). Results: We …

Swift Spectroscopy Of The Accretion Disk Wind In The Black Hole Gro J1655-40, M. Balakrishnan, J. M. Miller, N. Trueba, M. Reynolds, J. Raymond, Daniel Proga, A. C. Fabian, T. Kallman, J. Kaastra

Physics & Astronomy Faculty Research

Chandra obtained two High Energy Transmission Grating spectra of the stellar-mass black hole GRO J1655−40 during its 2005 outburst, revealing a rich and complex disk wind. Soon after its launch, the Neil Gehrels Swift Observatory began monitoring the same outburst. Some X-ray Telescope (XRT) observations were obtained in a mode that makes it impossible to remove strong Mn calibration lines, so the Fe Kα line region in the spectra was previously neglected. However, these lines enable a precise calibration of the energy scale, facilitating studies of the absorption-dominated disk wind and its velocity shifts. Here we present fits to 15 …

Alma 0.88 Mm Survey Of Disks Around Planetary-Mass Companions, Ya-Lin Wu, Brendan P. Bowler, Patrick D. Sheehan, Sean M. Andrews, Gregory J. Herczeg, Adam L. Kraus, Luca Ricci, David J. Wilner, Zhaohuan Zhu

Physics & Astronomy Faculty Research

Characterizing the physical properties and compositions of circumplanetary disks can provide important insights into the formation of giant planets and satellites. We report Atacama Large Millimeter/submillimeter Array 0.88 mm (Band 7) continuum observations of six planetary-mass (10–20 M Jup) companions: CT Cha b, 1RXS 1609 b, ROXs 12 b, ROXs 42B b, DH Tau b, and FU Tau b. No continuum sources are detected at the locations of the companions down to 3σ limits of 120–210 μJy. Given these nondetections, it is not clear whether disks around planetary-mass companions indeed follow the disk-flux–host-mass trend in the stellar regime. The faint …

Arc‐Type Magmatism Due To Continental‐Edge Plowing Through Ancient Subduction‐Enriched Mantle, Douwe J.J. Van Hinsbergen, Wim Spakman, Hugo De Boorder, Michiel Van Dongen, Simon M. Jowitt, Paul R.D. Mason

Geoscience Faculty Research

The puzzling... (See article for full abstract).

Analysis Of Cryptotephra At Whitney Mesa Nature Preserve, Henderson, Nevada, Alex Newsom

Calvert Undergraduate Research Awards

Advanced Undergraduate Winner

Cryptotephra (small volcanic shards ranging 20-80 microns in size) were discovered within Unit X of the Las Vegas Formation at Whitney Mesa Nature Preserve, Henderson, Nevada. Cryptotephra are deposited soon after a volcanic eruption and can be used as a dating tool to create narrow time constraints for surrounding sediments. Cryptotephra have many applications but are mainly useful as a dating tool. Their study has important implications for the understanding of the timing of palaeoclimatological and paleoenvironmental events as well as for archaeological studies to date important events in human history.

The Whitney Mesa cryptotephra were correlated …

Insight On Thermal Stability Of Magnetite Magnetosomes: Implications For The Fossil Record And Biotechnology, Jefferson Cypriano, Mounib Bahri, Kassioge Dembele, Walid Baaziz, Pedro Leao, Dennis A. Bazylinski, Fernanda Abreu, Ovidiu Ersen, Marcos Farina, Jacques Werckmann

Life Sciences Faculty Research

Magnetosomes are intracellular magnetic nanocrystals composed of magnetite (Fe3O4) or greigite (Fe3S4), enveloped by a lipid bilayer membrane, produced by magnetotactic bacteria. Because of the stability of these structures in certain environments after cell death and lysis, magnetosome magnetite crystals contribute to the magnetization of sediments as well as providing a fossil record of ancient microbial ecosystems. The persistence or changes of the chemical and magnetic features of magnetosomes under certain conditions in different environments are important factors in biotechnology and paleomagnetism. Here we evaluated the thermal stability of magnetosomes in a temperature range between 150 and 500 °C subjected …

Writing Excess: Theoretical Waste, Responsibility, And The Post Qualitative Inquiry, Susan Ophelia Cannon, Stephanie Behm Cross

Taboo: The Journal of Culture and Education

No abstract provided.

Science And Scientific Discoveries: Through The Lens Of Critical Pedagogies, Aristotelis S. Gkiolmas, Anthimos Chalkidis

Taboo: The Journal of Culture and Education

No abstract provided.

On-Chip Terahertz Modulation And Emission With Integrated Graphene Junctions, Joshua O. Island, Peter Kissin, Jacob Schalch, Xiaomeng Cui, Sheikh Rubaiat Ui Haque, Alex Potts, Takashi Taniguchi, Kanji Watanabe, Richard D. Averitt, Andrea F. Young

Physics & Astronomy Faculty Research

The efficient modulation and control of ultrafast signals on-chip is of central importance in terahertz (THz) communications and a promis- ing route toward sub-diffraction limit THz spectroscopy. Two-dimensional (2D) materials may provide a platform for these endeavors. We explore this potential, integrating high-quality graphene p–n junctions within two types of planar transmission line circuits to modulate and emit picosecond pulses. In a coplanar strip line geometry, we demonstrate the electrical modulation of THz signal transmission by 95%. In a Goubau waveguide geometry, we achieve complete gate-tunable control over THz emission from a photoexcited graphene junction. These studies inform the development …

Vibration Overtone Hyperpolarizability Measured For H2, Rachel M. Ellis, David P. Shelton

Physics & Astronomy Faculty Research

The second hyperpolarizability (γ) of the H2 molecule was measured by gas-phase electric field induced second harmonic generation at the frequencies of the one-photon resonance for the 3–0 Q(J) overtone transitions (v, J = 0, J → 3, J for J = 0, 1, 2, and 3). The magnitude of the resonant contribution to γ was measured with 2% accuracy using the previously determined non-resonant γ for calibration. Pressure broadening and frequency shift for the transitions were also measured. A theoretical expression for the resonant vibrational γ contribution in terms of transition polarizabilities is compared to the observations. The measured …

Residual-Matching: An Efficient Alternative To Random Sampling In Human Subjects Research Recruitment, Andrew Hooyman, Matthew J. Huentelman, Sydney Y. Schaefer

Kinesiology and Nutrition Sciences Faculty Research

Given the time- and resource-intense nature of human subjects research, we have developed a more intelligent approach to participant recruitment above and beyond random sampling that leverages pilot or preliminary results to reduce the overall number of participants needed for recruitment from an existing electronic cohort or database. Using open-access data from the General Social Survey (GSS) of the National Opinion Research Center, we generated pilot and validation datasets through a simulation to establish moderate and weak relationships based on linear regression. We then compared the performance of our residual-matching method against random sampling in their probabilities of achieving a …

Structure-Strength Relations Of Distinct Mon Phases From First-Principles Calculations, Cheng Lu, Changfeng Chen

Physics & Astronomy Faculty Research

Molybdenum mononitrides (MoN) exhibit superior strength and hardness among the large class of transition-metal light-element compounds, but the underlying atomistic mechanisms for their outstanding mechanical properties and the variations of those properties among various MoN phases adopting different crystal structures remain largely unexplored and require further investigation. Here we report first-principles calculations that examine the stress-strain relations of these materials, and systematically compare results under pure and indentation shear deformations. In particular, we examine the distinct bonding structures and the associated mechanical properties in four different crystal phases of MoN that have been experimentally synthesized and stabilized under various physical …

Ensemble Modeling Of Auditory Streaming Reveals Potential Sources Of Bistability Across The Perceptual Hierarchy, David F. Little, Joel S. Snyder, Mounya Elhilali

Psychology Faculty Research

Perceptual bistability—the spontaneous, irregular fluctuation of perception between two interpretations of a stimulus—occurs when observing a large variety of ambiguous stimulus configurations. This phenomenon has the potential to serve as a tool for, among other things, understanding how function varies across individuals due to the large individual differences that manifest during perceptual bistability. Yet it remains difficult to interpret the functional processes at work, without knowing where bistability arises during perception. In this study we explore the hypothesis that bistability originates from multiple sources distributed across the perceptual hierarchy. We develop a hierarchical model of auditory processing comprised of three …

Indentation-Strain Stiffening In Tungsten Nitrides: Mechanisms And Implications, Cheng Lu, Changfeng Chen

Physics & Astronomy Faculty Research

We report on a systematic computational study of ideal strengths, i.e., the lowest stresses needed to destabilize a perfect crystal under a variety of loading conditions for six stable and metastable tungsten nitrides identified by advanced crystal structure search algorithms. We employ first-principles calculations to determine stress-strain relations and examine the corresponding atomistic bonding changes for a microscopic understanding of the structural deformation modes. The obtained results show that, in stark contrast to many previously studied transition-metal borides, carbides, and also most nitrides, the tungsten nitrides exhibit surprisingly broad and common patterns of strain-stiffening effects under indentation strains. These extraordinary …

Using Fuzzy Models And Time Series Analysis To Predict Water Quality, Zhao Fu, Mei Yang, Jacimaria R. Batista

Electrical & Computer Engineering Faculty Research

Water quality prediction is very important for both water resource scheduling and management. Simple linear regression analysis and artificial neural network models cannot accurately forecast water quality because of complicated linear and nonlinear relationships in the water quality dataset. An adaptive neuro-fuzzy inference system (ANFIS) that can integrate linear and nonlinear relationships has been proposed to address the problem. However, the ANFIS model can only work in scenarios where input and target parameters have strong correlations. In this paper, a fuzzy model integrated with a time series data analysis method is proposed to address the water quality prediction problem when …

Global 3d Radiation Magnetohydrodynamic Simulations For Fu Ori's Accretion Disc And Observational Signatures Of Magnetic Fields, Zhaohuan Zhu, Yan-Fei Jiang, James M. Stone

Physics & Astronomy Faculty Research

FU Ori is the prototype of FU Orionis systems that are outbursting protoplanetary discs. Magnetic fields in FU Ori’s accretion discs have previously been detected using spectropolarimetry observations for Zeeman effects. We carry out global radiation ideal MHD simulations to study FU Ori’s inner accretion disc. We find that (1) when the disc is threaded by vertical magnetic fields, most accretion occurs in the magnetically dominated atmosphere at z ∼ R, similar to the ‘surface accretion’ mechanism in previous locally isothermal MHD simulations. (2) A moderate disc wind is launched in the vertical field simulations with a terminal speed of …