Digital Commons Network^™

Measurement Of Anterior Translation Of The Mandibular Condyle Using Sonography, Kai-Yu Ho, Brooke Laskowski, Danielle Garcia, Christensen J. Hardy, Emilio Puentedura

Physical Therapy Faculty Research

[Purpose] To establish a standardized sonographic approach to quantify anterior translation of the mandibular condyle during mouth opening by examining the reliability of image acquisition and processing, and to understand how anterior condylar translation contributes to mouth opening. [Participants and Methods] Twenty-eight participants without temporomandibular disorder (TMD) participated. During day 1 of data collection, all participants performed maximal mouth opening while an examiner recorded anterior condylar translation using sonography. The mouth opening range of motion was also obtained. On day 2 of data collection, the same procedure was performed on 6 participants that participated in day 1 of data collection. …

Speleothem Paleoclimatology For The Caribbean, Central America, And North America, Jessica L. Oster, Sophie F. Warken, Natasha Sekhon, Monica M. Arienzo, Matthew Lachniet

Geoscience Faculty Research

Speleothem oxygen isotope records from the Caribbean, Central, and North America reveal climatic controls that include orbital variation, deglacial forcing related to ocean circulation and ice sheet retreat, and the influence of local and remote sea surface temperature variations. Here, we review these records and the global climate teleconnections they suggest following the recent publication of the Speleothem Isotopes Synthesis and Analysis (SISAL) database. We find that low-latitude records generally reflect changes in precipitation, whereas higher latitude records are sensitive to temperature and moisture source variability. Tropical records suggest precipitation variability is forced by orbital precession and North Atlantic Ocean …

Late Delivery Of Nitrogen To The Earth, Cheng Chen, Jeremy L. Smallwood, Rebecca G. Martin, Mario Livio

Physics & Astronomy Faculty Research

Atmospheric nitrogen may be a necessary ingredient for the habitability of a planet as its presence helps to prevent water loss from a planet. The present-day nitrogen isotopic ratio, N-15/N-14, in the Earth's atmosphere is a combination of the primitive Earth's ratio and the ratio that might have been delivered in comets and asteroids. Asteroids have a nitrogen isotopic ratio that is close to the Earth's. This indicates either a similar formation environment to the Earth or that the main source of nitrogen was delivery by asteroids. However, according to geological records, the Earth's atmosphere could have been enriched in …

Determinants Of Customer Satisfaction At The San Francisco International Airport, Ashok K. Singh, Myongjee Yoo, Rohan Dalpatadu

Hospitality Faculty Research

This study attempts to determine the overall satisfaction factors from airline passengers at the San Francisco International Airport (SFO), using the classification method of random forest. The analysis is based on the 2014 annual survey conducted by SFO that collects data on passenger demographics and satisfaction with airport facilities and services. Results of this study indicate that some service attributes are more important than others for passengers’ overall satisfaction at SFO. Study results are expected to provide practical insights to the airport industry. This study, in addition, introduces the machine learning method of random forest to tourism research.

Elastic Plastic Self-Consistent (Epsc) Modeling Of San Carlos Olivine Deformed In A D-Dia Apparatus, Pamela C. Burnley, Shirin Kaboli

Geoscience Faculty Research

We present a suite of low strain deformation experiments conducted on polycrystalline San Carlos olivine in a deformation DIA apparatus at temperatures ranging from 440 to 1106 °C at pressures between 3.8 and 4.6 GPa. The deformation behavior was monitored using in situ diffraction of white synchrotron X‑rays. The experiments were conducted at a slow strain rate of ~5 × 10–6/s so as to allow the initial elastic behavior to be closely monitored. For each experiment, we fit the diffraction data using elastic plastic self-consistent (EPSC) models. We find that to model the experiments we must incorporate an isotropic deformation …

Inferring The Distribution Of Selective Effects From A Time Inhomogeneous Model, Amei Amei, Shilei Zhour

Mathematical Sciences Faculty Research

We have developed a Poisson random field model for estimating the distribution of selective effects of newly arisen nonsynonymous mutations that could be observed as polymorphism or divergence in samples of two related species under the assumption that the two species populations are not at mutation-selection-drift equilibrium. The model is applied to 91Drosophila genes by comparing levels of polymorphism in an African population of D. melanogaster with divergence to a reference strain of D. simulans. Based on the difference of gene expression level between testes and ovaries, the 91 genes were classified as 33 male-biased, 28 female-biased, and 30 sex-unbiased …

Dynamical Instability And Its Implications For Planetary System Architecture, Dong-Hong Wu, Rachel C. Zang, Ji-Lin Zhou, Jason H. Steffen

Physics & Astronomy Faculty Research

We examine the effects that dynamical instability has on shaping the orbital properties of exoplanetary systems. Using N-body simulations of non-EMS (Equal Mutual Separation), multiplanet systems we find that the lower limit of the instability time-scale t is determined by the minimal mutual separation Kmin in units of the mutual Hill radius. Planetary systems showing instability generally include planet pairs with period ratio... (See abstract in article).

Joint Determination Of Residential Relocation And Commuting: A Forecasting Experiment For Sustainable Land Use And Transportation Planning, Jaewon Lim, Jae Hong Kim

Public Policy and Leadership Faculty Research

This article applies matrix forecasting methods to the investigation of residential relocation and commuting patterns that are highly interconnected, but often analyzed separately. More specifically, using recent inter-county migration and commuting pattern data for the three largest metropolitan areas in California, it examines how residential relocation and commuting are associated in the regions and whether a unified framework—in which household relocation and commuting flow matrices are jointly determined—can improve the forecasting performance. The relocation–commuting association is found to differ substantially by region, suggesting the importance of region-specific factors in shaping the interrelationship. Joint forecasting, however, can attain a higher accuracy …

Retaining Nevada’S Teachers: Issues And Solutions, Iesha Jackson, Lois Paretti, Linda Quinn, Dana Bickmore, Matthew Borek

Policy Issues in Nevada Education: Policy Papers

Teacher attrition and retention present an immediate, undesirable challenge for education in Nevada. While an increase in enrollment in the student population necessitates an increase in teachers, teacher retention rates across the state of Nevada range from 14 percent in Pershing County to 30 percent in Clark County and 75 percent in Mineral County from 2012-2015. In addition to the disadvantages to students when teachers leave the profession, there is also a substantial cost to districts. Research in urban settings suggests that replacing a new teacher in a district can range from $12,000 to more than $26,000. Factors that help …

Career Handbook, Unlv Career Services

Career Handbook

The job search, no matter what step you are on, can be a daunting and intimidating process. We want you to know that you are not alone in this journey. Since the day you arrived on campus, you have been surrounded by the support of family, friends, professors, staff, and peers. As you move into the next stage of your professional journey, we want you to know that you have the support of Career Services, the Alumni Association, and all of the employers who are part of the Hire a Rebel family to mentor, guide, and walk with you through …

Aligning Best Practices In Student Success And Career Preparedness: An Exploratory Study To Establish Pathways To Stem Careers For Undergraduate Minority Students, Kimberly D. Kendricks, Anthony A. Arment, K. V. Nedunuri, Cadance A. Lowell

Journal of Research in Technical Careers

Undergraduate minority retention and graduation rates in STEM disciplines is a nationally recognized challenge for workforce growth and diversification. The Benjamin Banneker Scholars Program (BBSP) was a five-year undergraduate study developed to increase minority student retention and graduation rates at an HBCU. The program structure utilized a family model as a vehicle to orient students to the demands of college. Program activities integrated best K-12 practices and workforce skillsets to increase academic preparedness and career readiness. Findings revealed that a familial atmosphere improved academic performance, increased undergraduate research, and generated positive perceptions of faculty mentoring. Retention rates among BBSP participants …

Contributors To Success On The Automotive Service Excellence (Ase) Student Certification Exam, Robert K. Vlacich, Mark D. Threeton, Kyungin Kim

Journal of Research in Technical Careers

This study sought to identify which elements contribute to success on the Automotive Service Excellence (ASE) Student Certification exam. Students at an eastern U.S. technical college who completed all of their automotive major courses and the ASE Student Certification exam during the spring 2017 semester were selected for the study. The results of this study revealed that there was a direct correlation between performance in Physics, Algebra, and Trigonometry 1 and performance on the ASE Student Certification exam. It was also revealed that students who were required to participate in remedial math and/or remedial reading courses were likely to perform …

The Flipped Classroom And Its Impact On Student Engagement And Academic Performance In A Culinary Arts, Career And Technical Education Program, Michael Holik

Journal of Research in Technical Careers

The purpose of this study was to gather evidence from a CTE culinary arts program to determine if students perform better academically and are more engaged in the flipped classroom using digital technology, than the traditional classroom. The study included 24 participants in a post-secondary, CTE culinary arts program who were divided into two groups of 12: a traditional, teacher-centered group and a flipped, student-centered group. Utilizing action-based research, surveys, journals, and an engagement matrix were created and used. Although not statistically significant, student grades in the flipped classroom were nearly 4% higher than those in the traditional classroom and …

An Analysis Of Cooperating Teacher Feedback: A Qualitative Inquiry, Christopher J. Eck, Jon W. Ramsey

Journal of Research in Technical Careers

Cooperating teachers are a key component to the success of student teaching internships, serving an integral part in “raising” a teacher. To effectively facilitate the student teaching internship, teacher preparation programs must identify cooperating teachers who align philosophically with the pedagogical training delivered by university programs (Korthagen & Kessels, 1999; Tom, 1997), specifically, cooperating teachers who can reinforce the theoretical framework underpinning the professional coursework pre-service teachers experience in university teacher preparation programs. This qualitative study sought to better understand the feedback provided to future school-based agricultural education (SBAE) teachers during their student teaching experience. Through initial and secondary coding, …

A Case Study Of The Development Of A Career Academy: Good Intentions Not Enough?, Victor M. Hernandez-Gantes, Edward C. Fletcher Jr., Sasha Keighobadi

Journal of Research in Technical Careers

The purpose of this study was to explore how a career academy featuring an information technology (IT) theme approached the adoption of the model and the particular curricular focus. We used a case study design to explore the experiences of school personnel and community partners associated with the implementation of the career academy. We found that growing enrollment in the local district was a major driver to pursue small school designs as an alternative to the traditional high school comprehensive model. The small school size associated with small learning communities was valued by stakeholders and used to adopt and implement …

Predictors Of Adolescents’ Interest In Stem Majors And Careers, Ei Myint

Calvert Undergraduate Research Awards

Advanced Research Winner 2019:

The United States currently faces a shortage of qualified workers in fields related to science, technology, engineering, and math (STEM). The first critical step in preventing the labor shortage in STEM is understanding the factors that guide adolescents toward STEM pursuits. Drawing on Eccles’ expectancy-value theory (EVT), the current study aims to identify factors that are relevant to adolescents’ interest in STEM majors and careers. Data were collected from 629 adolescents (M_age = 16.09). Participants attended a high school in northern California and predominantly identified as Asian American (82% of the sample). Preliminary analyses …

The Influence Of The Warren Court And Natural Rights On Substantive Due Process, James Marmaduke

Calvert Undergraduate Research Awards

Advanced Research Winner 2019:

While the concept of substantive due process has guided judicial decision making even prior to the Civil War, it has become a lightning rod among the juristic community especially since the 1960s. This controversy includes issues ranging from the applicability and reliability to the cogency and legitimacy of the doctrine of substantive due process Many scholars attribute the skepticism toward the concept of substantive due process to be the result of a paradigm shift in the middle of the 20^th century when this concept transitioned from an economic and property rights based approach to one …

A Graph-Based Reinforcement Learning Method With Converged State Exploration And Exploitation, Han Li, Tianding Chen, Hualiang Teng, Yingtao Jiang

Civil and Environmental Engineering and Construction Faculty Research

In any classical value-based reinforcement learning method, an agent, despite of its continuous interactions with the environment, is yet unable to quickly generate a complete and independent description of the entire environment, leaving the learning method to struggle with a difficult dilemma of choosing between the two tasks, namely exploration and exploitation. This problem becomes more pronounced when the agent has to deal with a dynamic environment, of which the configuration and/or parameters are constantly changing. In this paper, this problem is approached by first mapping a reinforcement learning scheme to a directed graph, and the set that contains all …

Distributed Lagrange Multiplier/Fictitious Domain Finite Element Method For A Transient Stokes Interface Problem With Jump Coefficients, Andrew Lundberg, Pengtao Sun, Cheng Wang, Chen-Song Zhang

Mathematical Sciences Faculty Research

The distributed Lagrange multiplier/fictitious domain (DLM/FD)-mixed finite element method is developed and analyzed in this paper for a transient Stokes interface problem with jump coefficients. The semi- and fully discrete DLM/FD-mixed finite element scheme are developed for the first time for this problem with a moving interface, where the arbitrary Lagrangian-Eulerian (ALE) technique is employed to deal with the moving and immersed subdomain. Stability and optimal convergence properties are obtained for both schemes. Numerical experiments are carried out for different scenarios of jump coefficients, and all theoretical results are validated.

Fostering A Culture Of Innovation: A Case Study Of Elementary School Principals In Costa Rica, Miguel M. Gonzales, Richard Sorti

Educational Psychology, Leadership, and Higher Education Faculty Research

To help promote a culture of innovation, the Ministry of Education and the Ministry of Science, Technology, and Telecommunication of Costa Rica established a national executive decree requiring all public schools in the country participate in the National Program of Science and Technology Fairs (NPSTF). This case study examines the role of five elementary school principals in Costa Rica in implementing and preparing their schools for the NPSTF initiative. Principals played three significant roles: the motivator of teachers and students; acquirer of NPSTF resources; and the organizer of NPSTF committees and coalitions to help train and finance the initiative. It …

First-Principles Investigation Of Sc-Iii/Iv Under High Pressure, Sheng-Cai Zhu, Xiao-Zhi Yan, Scott Fredericks, Yan-Ling Li, Qiang Zhu

Physics & Astronomy Faculty Research

Using an ab initio evolutionary structure prediction method in conjunction with density functional theory, we performed a systematic investigation of the structural transition of elemental scandium under pressure up to 250 GPa. Our prediction successfully reproduced several allotropes which have been reported in the literature, including the Sc-I, Sc-II, and Sc-V. Moreover, we observed a series of energetically degenerate and geometrically similar structures at 110–195 GPa, which can partly explain the experimental observations regarding the unsolved phases III and IV reported by Y. Akahama et al. [Phys. Rev. Lett. 94, 195503 (2005)]. A detailed comparison of the powder x-ray diffraction …

The Disk Substructures At High Angular Resolution Project (Dsharp). I. Motivation, Sample, Calibration, And Overview, Sean M. Andrews, Jane Huang, Laura M. Pérez, Andrea Isella, Cornelis P. Dullemond, Nicolás T. Kurtovic, Viviana V. Guzmán, John M. Carpenter, David J. Wilner, Shangjia Zhang, Zhaohuan Zhu, Tilman Birstiel, Xue-Ning Bai, Myriam Benisty, A. Meredith Hughes, Karin I. Öberg, Luca Ricci

Physics & Astronomy Faculty Research

We introduce the Disk Substructures at High Angular Resolution Project (DSHARP), one of the initial Large Programs conducted with the Atacama Large Millimeter/submillimeter Array (ALMA). The primary goal of DSHARP is to find and characterize substructures in the spatial distributions of solid particles for a sample of 20 nearby protoplanetary disks, using very high resolution (~0 035, or 5 au, FWHM) observations of their 240 GHz (1.25 mm) continuum emission. These data provide a first homogeneous look at the small-scale features in disks that are directly relevant to the planet formation process, quantifying their prevalence, morphologies, spatial scales, spacings, symmetry, …

The Disk Substructures At High Angular Resolution Project (Dsharp). Iii. Spiral Structures In The Millimeter Continuum Of The Elias 27, Im Lup, And Waoph 6 Disks, Jane Huang, Sean M. Andrews, Laura M. Pérez, Zhaohuan Zhu, Cornelis P. Dullemond, Andrea Isella, Myriam Benisty, Xue-Ning Bai, Tilman Birnstiel, John M. Carpenter, Viviana V. Guzmán, A. Meredith Hughes, Karin I. Öberg, Luca Ricci, David J. Wilner, Shangjia Zhang

Physics & Astronomy Faculty Research

We present an analysis of Atacama Large Millimeter/submillimeter Array 1.25 mm continuum observations of spiral structures in three protoplanetary disks from the Disk Substructures at High Angular Resolution Project. See full text for full abstract.

The Disk Substructures At High Angular Resolution Project (Dsharp). Ii. Characteristics Of Annular Substructures, Jane Huang, Sean M. Andrews, Cornelis P. Dellemond, Andrea Isella, Laura M. Pérez, Viviana V. Guzmán, Karin I. Öberg, Zhaohuan Zhu, Shangjia Zhang, Xue-Ning Bai, Myriam Benisty, Tilman Birstiel, John M. Carpenter, A. Meredith Hughes, Luca Ricci, Erik Weaver, David J. Wilner

Physics & Astronomy Faculty Research

The Disk Substructures at High Angular Resolution Project (DSHARP) used ALMA to map the 1.25 mm continuum of protoplanetary disks at a spatial resolution of ~5 au. We present a systematic analysis of annular substructures in the 18 single-disk systems targeted in this survey. No dominant architecture emerges from this sample; instead, remarkably diverse morphologies are observed. Annular substructures can occur at virtually any radius where millimeter continuum emission is detected and range in widths from a few astronomical units to tens of astronomical units. Intensity ratios between gaps and adjacent rings range from near-unity to just a few percent. …

The Disk Substructures At High Angular Resolution Project (Dsharp). Vi. Dust Trapping In Thin-Ringed Protoplanetary Disks, Cornelis P. Dullemond, Tilman Birnstiel, Jane Huang, Nicolás T. Kurtovic, Sean M. Andrews, Viviana V. Guzmán, Laura M. Pérez, Andrea Isella, Zhaohuan Zhu, Myriam Benisty, David J. Wilner, Xue-Ning Bai, John M. Carpenter, Shangjia Zhang, Luca Ricci

Physics & Astronomy Faculty Research

A large fraction of the protoplanetary disks observed with ALMA display multiple well-defined and nearly perfectly circular rings in the continuum, in many cases with substantial peak-to-valley contrast. The DSHARP campaign shows that several of these rings are very narrow in radial extent. In this Letter we test the hypothesis that these dust rings are caused by dust trapping in radial pressure bumps, and if confirmed, put constraints on the physics of the dust trapping mechanism. We model this process analytically in 1D, assuming axisymmetry. By comparing this model to the data, we find that all rings are consistent with …

The Disk Substructures At High Angular Resolution Project (Dsharp). Vii. The Planet–Disk Interactions Interpretation, Shangjia Zhang, Zhaohuan Zhu, Jane Huang, Viviana V. Guzmán, Sean M. Andrews, Tilman Birnstiel, Cornelis P. Dullemond, John M. Carpenter, Andrea Isella, Laura M. Pérez, Myriam Benisty, David J. Wilner, Clément Baruteau, Xue-Ning Bai, Luca Ricci

Physics & Astronomy Faculty Research

The Disk Substructures at High Angular Resolution Project (DSHARP) provides a large sample of protoplanetary disks with substructures that could be induced by young forming planets. To explore the properties of planets that may be responsible for these substructures, we systematically carry out a grid of 2D hydrodynamical simulations, including both gas and dust components. We present the resulting gas structures, including the relationship between the planet mass, as well as (1) the gaseous gap depth/width and (2) the sub/super-Keplerian motion across the gap. We then compute dust continuum intensity maps at the frequency of the DSHARP observations. We provide …

The Disk Substructures At High Angular Resolution Program (Dsharp). Viii. The Rich Ringed Substructures In The As 209 Disk, Viviana V. Guzmán, Jane Huang, Sean M. Andrews, Andrea Isella, Laura M. Pérez, John M. Carpenter, Cornelis P. Dullemond, Luca Ricci, Tilman Birnstiel, Shangjia Zhang, Zhaohuan Zhu, Xue-Ning Bai, Myriam Benisty, Karin I. Öberg, David J. Wilner

Physics & Astronomy Faculty Research

The Disk Substructures at High Angular Resolution Program (DSHARP). VIII. The Rich Ringed Substructures in the AS 209 Disk

The Disk Substructures At High Angular Resolution Project (Dsharp). Iv. Characterizing Substructures And Interactions In Disks Around Multiple Star Systems, Nicolás T. Kurtovic, Laura M. Pérez, Myriam Benisty, Zhaohuan Zhu, Shangjia Zhang, Jane Huang, Sean M. Andrews, Cornelis P. Dullemond, Andrea Isella, Xue-Ning Bai, John M. Carpenter, Viviana V. Guzmán, Luca Ricci, David J. Wilner

Physics & Astronomy Faculty Research

To characterize the substructures induced in protoplanetary disks by the interaction between stars in multiple systems, we study the 1.25 mm continuum and the 12CO(J = 2–1) spectral line emission of the triple systems HT Lup and AS 205, at scales of ≈5 au, as part of the "Disk Substructures at High Angular Resolution Project" (DSHARP). In the continuum emission, we find two symmetric spiral arms in the disk around AS 205 N, with a pitch angle of 14°, while the southern component AS 205 S, itself a spectroscopic binary, is surrounded by a compact inner disk and a bright …

Efl Teachers’ Preparation And Beliefs In Niger, Peter Wiens, Bong Gee Jang, Katrina Liu, Billa Anassour, April Smith

Teaching and Learning Faculty Research

Niger is a French-speaking country with a history of teaching English as a foreign language (EFL) in its middle and high schools. The teachers providing instruction in these programs have been trained in different ways including university-based programs, out of country programs, or no training at all. This study sought to examine the beliefs of Nigerien EFL teachers and analyze the relationship between their beliefs and their training. All EFL teachers in Niger were surveyed to understand their beliefs related to teaching. We found that training was related to teacher beliefs. As Niger determines how best to allocate its limited …

The Disk Substructures At High Angular Resolution Project (Dsharp). X. Multiple Rings, A Misaligned Inner Disk, And A Bright Arc In The Disk Around The T Tauri Star Hd 143006, Laura M. Pérez, Myriam Benisty, Sean M. Andrews, Andrea Isella, Cornelis P. Dellemond, Jane Huang, Nicolás T. Kurtovic, Viviana V. Guzmán, Zhaohuan Zhu, Tilman Birnstiel, Shangjia Zhang, John M. Carpenter, David J. Wilner, Luca Ricci, Xue-Ning Bai, Erik Weaver, Karin I. Öberg

Physics & Astronomy Faculty Research

We present a detailed analysis of new Atacama Large Millimeter/submillimeter Array (ALMA) observations of the disk around the T-Tauri star HD 143006, which at 46 mas (7.6 au) resolution reveals new substructures in the 1.25 mm continuum emission. The disk resolves into a series of concentric rings and gaps, together with a bright arc exterior to the rings that resembles hydrodynamical simulations of a vortex and a bridge-like feature connecting the two innermost rings. Although our 12CO observations at similar spatial resolution do not show obvious substructure, they reveal an inner disk depleted of CO emission. From the continuum emission …