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Examining Arctic Melt Pond Dynamics via High Resolution Satellite Imagery
2021Austin Abbott and Victoria Hill
The Arctic Ocean is a rapidly changing environment, and a key observational system for monitoring climate change. The Arctic is going under a rapid transition from thicker, multi-year ice, to thinner first-year ice, that may have many potential consequences. As first year Arctic sea ice begins to retreat in the spring and early summer, melting snow and ice form ponds on the surface- “melt ponds”. These melt ponds increase light transmission to the water column, resulting in warming and increased primary production under the ice. Recent advances in high resolution satellite imagery now allow us to monitor the development and propagation of melt ponds from space. 14 Worldview images (privately owned) of first year ice in the Chukchi Sea with sub-meter scale spatial resolution were recorded from June and July 2018 and classified into 4 distinct classes- Un-ponded Ice, Dark Melt Pond, Light Melt Pond, and Open Water. Classification data were analyzed for melt pond abundance (pond fraction) and size. Pond growth can be described by either a linear or logistic growth function (r2 = 0.86). Additionally, previously recorded light transmission values can be used to create an under-ice light availability budget based on class distribution data. This allows for estimates of primary production and the prediction of below ice phytoplankton blooms. As the Arctic continues to experience an extreme regime shift, increased monitoring of melt ponds and other rapidly changing systems will be essential
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Nanopore Guided Regional Assembly
2021Eleni Adam, Desh Ranjan, and Harold Riethman
The telomeres are the “caps” of the chromosomes and their vital role is to protect them. Possible telomere dysfunction caused by telomere rearrangements can be fatal for the cell and result in age-related diseases, including cancer. The telomeres and subtelomeres are regions that are hard to investigate. The current technology cannot provide their complete sequence, instead the DNA is given in multiple pieces. Current methods of assembling the pieces of these regions are not accurate enough due to the region’s high variability and complex repeated patterns. We propose a hybrid assembly method, the NPGREAT, which utilizes two of the latest available data: Linked-Reads and ultralong Nanopore reads. It consists of five main steps: (i) The input selection of the data, (ii) the Orientation, Order and Enhanced Correction of the short contigs by using the long reads as scaffolds, upon which the short contigs are mapped to. Particularly, the Enhanced Correction step allows for the correction of potential misassemblies within the short contigs due to deletions in tandem repeat regions. The nanopore sequence is used to fill the missing portion, representing the tandem repeat region accurately, a region which is highly variable from one human to another. Next, in the (iii) Region Extraction step, the segments of the multiple long reads that can be used to connect the short contigs, are extracted. Then, in the (iv) Gap Filling step, all possible segments are taken into account and one is selected to fill each gap. Finally, in the (v) Combination step, the corrected short pieces are combined with the connector segments. The output is the subtelomere region of the chromosome. NPGREAT is evaluated with the use of the QUAST tool and the resulting assemblies are of high quality.
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Computational Aerodynamics of a Wing Mounted Propeller
2021Sarah Agam
Computational fluid dynamics (CFD) is a vital component in aerospace engineering. A major use of CFD is analyzing the flow properties to determine outputs like aerodynamic lift and drag over an airfoil or compute engine efficiency. It is more practical to conduct a CFD analysis first before doing experimental work as CFD allows for rapid and diverse testing of propeller shapes at a lower cost. CFD also allows for a wider range of testing parameters; for example, an airfoil can be subjected to steady, unsteady, incompressible, or high velocity flows.
Propellers are extensively used in the aircraft industry, especially in smaller vehicles. A potential application for shape optimization is for urban air mobility vehicles. The concept for this idea is that autonomous drones can fly people over cities. It is important to understand how the flow around the propeller affects the flow properties, such as the pressure distribution, velocity distribution, and coefficient of thrust. As the propeller rotates, the air goes over the blades from the leading edge to the trailing edge. If the shape of the propeller blades is properly designed, favorable pressure and velocity distributions are created which in-turn produce the thrust. The purpose of this research is to use CFD to conduct shape optimization on a given propeller blade design to increase aerodynamic efficiency and produce the desired thrust and lift.
A propeller from a given case study will be analyzed. The normal, radial, and swirl velocities, thrust and torque distributions, and total pressure will be calculated from both an isolated propeller study and a wing mounted study. Then, the propellers will undergo a mesh independence study and afterwards subjected to certain boundary and initial conditions for CFD computation. Finally, the converged, optimized solutions will be analyzed and will be compared to the original case study.
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End-to-End Physics Event Generator
2021Yasir Alanazi, N. Sato, Tianbo Liu, W. Melnitchouk, Michelle P. Kuchera, Evan Pritchard, Michael Robertson, Ryan Strauss, Luisa Velasco, and Yaohang Li
We apply generative adversarial network (GAN) technology to build an event generator that simulates particle production in electron-proton scattering that is free of theoretical assumptions about underlying particle dynamics. The difficulty of efficiently training a GAN event simulator lies in learning the complicated pat- terns of the distributions of the particles physical properties. We develop a GAN that selects a set of transformed features from particle momenta that can be generated easily by the generator, and uses these to produce a set of augmented features that improve the sensitivity of the discriminator. The new Feature-Augmented and Transformed GAN (FAT-GAN) is able to faithfully reproduce the distribution of final state electron momenta in inclusive electron scattering, without the need for input derived from domain-based theoretical assumptions. The developed technology can play a significant role in boosting the science of the Jefferson Lab 12 GeV program and the future Electron-Ion Collider.
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VAIM for Solving Inverse Problems
2021Manal Almaeen, Yasir Alanazi, Michelle Kuchera, Nobuo Sato, Wally Melnitchouk, and Yaohang Li
In this work, we propose the Variational Autoencoder Inverse Mapper (VAIM) to solve inverse problems, where there is a demand to accurately restore hidden parameters from indirect observations. VAIM is an autoencoder-based neural network architecture. The encoder and decoder networks approximate the forward and backward mapping, respectively, and a variational latent layer is incorporated into VAIM to learn the posterior parameter distributions with respect to the given observables. VAIM shows promising results on several artificial inverse problems. VAIM further demonstrates preliminary effectiveness in constructing the inverse function mapping quantum correlation functions to observables in a quantum chromodynamics analysis of nucleon structure and hadronization.
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Teledentistry
2021Mishael Almukhalafi and Sharon C. Stull
Problem Statement: Healthy People 2030 strategic goals and objectives are focused on increasing health access and quality of care yet, millions of individuals still experience shortages of available oral health care services, limited oral health care providers, and living in rural areas, geographically distant from oral health care centers, all compounded by a current global pandemic.
Purpose: Investigate literature related to the role of teledentistry during a global pandemic and its associated benefits, effectiveness, and barriers on patient oral healthcare access and quality of care outcomes and to identify oral healthcare providers' knowledge, attitude, and perceptions on the utilization of teledentistry telecommunication tools during virtual patient visits.
Methodology: An extensive review of the literature was conducted utilizing electronic databases and websites of seminal journals and professional organizations and associations, in the English language. Specific databases used to conduct the literature reviews include EBSCO Host, PubMed, and CINHAL; accessed through Old Dominion University’s Libraries and direct access to the American Dental and Dental Hygienist’s Associations’ websites. Inclusion criteria were limited to peer-reviewed journals, the use of keyword searches such as Teledentistry, Telehealth, Telemedicine, pandemic, COVID 19, dental health, as well as documents exclusive to professional organizations such as Access, RDH magazine, and the American Dental Hygienist’s Association. Articles selected were no greater than ten years old.
Discussion: Telehealth or Telemedicine and Teledentistry are multidimensional solutions to these challenges providing remote patient monitoring, health and oral health promotion, using telecommunication and videoconferencing tools. All aligning with Healthy People 2030 goals and objectives by improving access and quality to health and oral healthcare services during a global pandemic.
Conclusion: There is emerging evidence supporting the effectiveness and efficacy of teledentistry in providing remote patient monitoring and consultation, and as a potential solution to increase access and quality of care during a global pandemic.
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Combine Cryo-EM Density Map and Residue Contact for Protein Structure Prediction: A Case Study
2021Maytha Alshammari and Jing He
Although atomic structures have been determined directly from cryo-EM density maps with high resolutions, current structure determination methods for medium resolution (5 to 10 Å) cryo-EM maps are limited by the availability of structure templates. Secondary structure traces are lines detected from a cryo-EM density map for α-helices and β-strands of a protein. A topology of secondary structures defines the mapping between a set of sequence segments in 1D and a set of traces of secondary structures in 3D. In order to enhance the accuracy in ranking secondary structure topologies, we propose a method that combines three sources of information – a set of sequence segments in 1D, a set of amino acid contact pairs in 2D, and a set of traces in 3D at the secondary structure level. A test of seven cases show that a small set of secondary structure topologies can be produced to include the true topology when the three sources of information are used, even when errors exist in one or more of the three sources of information. The use of amino acid contact information improves the ranking of the true topology in six of the seven cases in the test.
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Leadership in Collaborative Emergency Management and Resilience
2021Norah Alshayhan and Juita-Elena (Wie) Yusuf
Emergency management and resilience are key concepts and functions that are vital for mitigating risks of hazards and reducing the impacts of disasters. Public sector leaders within the emergency management and resilience domains play a critical role in leading the organization and its staff and partners in achieving these goals of risk mitigation and disaster impact reduction. This research investigates the skills and competencies that emergency management and resilience leaders need to be successful in collaborations to deal with emergencies and disasters today and in a post-COVID world. The study will employ a postpositivist case study design using interviews as an instrument to gain deep understanding of the important skillset and competencies identified by emergency management and resilience professionals. The study samples a target population of emergency management leaders and resilience professionals from the Mid-Atlantic region through snowball sampling. The sample will include emergency management and resilience professionals at the director or assistant director level (or equivalent), representing state, regional, and local government agencies and related functions in the private and nonprofit sectors. The study will develop understanding, based on the practices of emergency management and resilience professionals, of the critical skills and competencies needed to be effective in mitigating, preparing for, responding to, and recovering from disasters. Results of the research will provide insights for leadership development in these two domains.
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Information Communication Technology and Emergency Management Communication: Lessons from the 2020 ‘Hurricane-Pandemic’ Wave
2021Ren-Neasha Blake and Juita-Elena (Wie) Yusuf
The coronavirus pandemic [COVID-19] forged new roles, dynamics, and systems across the public administration and policy domain. The hurricane season approached just a few months after the COVID-19 outbreak and necessitated swift emergency management response. The usual planning for the hurricane season grappled with pandemic threats, clouds of fear, and the urgent need for reconfigured strategies. Policy practitioners, academicians, and non-government officials convened to construct and deconstruct cross-sector plans for navigating the hurricane-pandemic wave. These tweaked strategies were necessary for coastal communities like Hampton Roads that are prone to extreme weather events. Information communication technology (ICT) was at the forefront of resilience thrusts, especially for communicating and information sharing. There are growing studies on e-resilience that examine ICT infrastructural resilience in the face of emergencies and severe weather events. In this paper, the researchers explored ICT enablers for swift and consistent communication during a hurricane-pandemic wave. We also analyzed communication barriers and community needs during emergencies and discussed strategies for hurdling those barriers. We gathered data from the recently held CONVERGE Hurricane-Pandemic Workshops, led by Old Dominion University and the University of South Florida. We then grouped, coded, analyzed, and formed a qualitative sequential model for effective ‘hurricane-pandemic’ communication. This study is significant for informing emergency management policy and praxis in coastal communities globally.
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Educating Registered Nurses (RNs) to Improve Knowledge, Comfortability & Ability of Communication in Advance Care Planning (ACP)
2021Sirena Blount-Sears and Pamela Bishop
Purpose: The purpose of this project was to assess the knowledge, comfortability, and ability to communicate with confidence, along with the usage of communication tools, among Med/Surg RNs r/t to ACP before & after participation in an ACP educational webinar.
Aims: To evaluate whether the knowledge, comfortability, ability to communicate, including usage of communication tools, and confidence among medical-surgical registered nurses related to ACP improves following participation in an ACP educational webinar.
Research Questions/Hypotheses: RQ1: Will there be a significant difference before & after an ACP educational webinar r/t: knowledge, comfortability, ability to communicate with confidence, & the usage of ACP communication tools?
RQ2: Is there a significant correlation between the demographics of registered nurses & their knowledge, comfortability, & ability to communicate with confidence, along with utilization of ACP communication tools?
Significance: Findings of this project have improved nurse’s knowledge, comfortability, & ability to communicate with confidence and usage of communication tools of ACP.
Methods: The online educational webinar was offered to RNs on a Med/Surg unit of an acute care facility. Participants included RNs 18 years of age & over with varying demographic characteristics, educational backgrounds, & years of experience. Participants completed a Pre-Educational Survey, online educational webinar/training, & Post-Educational Survey.
Findings: Analyses includes descriptive statistics, correlations, & paired t-test to identify & compare pre & post educational surveys of an ACP educational webinar. Nurses’ ACP knowledge, comfortability, ability to communicate with confidence, along with the use of communication tools improved following their participation in an ACP educational webinar (increase in all variables (p=0.001)).
Discussion: Findings from this project have & will improve nurse’s knowledge, comfortability, & ability to communicate with confidence & usage of communication tools of ACP.
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On Being Seen
2021Shanisha Branch
I’ve always found it difficult to see. My poor eyesight I inherited from my father which didn’t make life easy. I remember asking to sit closer to the board than the rest of my classmates in elementary school. My teacher had made several attempts to write or call home asking my mother to get my eyes checked by a doctor. But, to me, I never found it much of a problem. I had been seeing with my blurry vision for as long as I could remember. Changing anything about that didn’t seem like much of a big deal… until I got my first pair of glasses. During that magical time before I started wearing them (and much of the time after), I had troubles truly seeing. Even though my vision had cleared up physically, I had a terrible time believing what I saw as true.
My vision for the majority of my life was dictated by others so much so that I had no agency. In fact, I’d say it was ignored. This one pleasure (or commodity) was stolen from me so often that I didn’t know how to operate when I actually had it. The problem with seeing something is that you can’t unsee it. Believe me, I’ve tried. My problem was twofold: I saw a lot and believed what I saw as true. My reality had been jaded so much so that I believed all that could happen could only be bad. These ideas dominate the journey through these pages. It is one toward love and self-discovery. These pages are filled with as much agency and fear and ugly and joys I could force myself to submit on a page. With hopes, of choosing to live those moments out more and more each day.
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The Influence of Lumbopelvic Function on Perceived Ankle Function in Individuals with Chronic Ankle Instability
2021Sunghoon Chung, A. M. B. Suttmiller, K. R. Johnson, and R. S. McCann
Perceived functional impairments measured via patient-reported outcomes (PROs) are associated with reduced postural control ability in CAI patients. Furthermore, hip and trunk neuromuscular impairments are critical factors that can cause decreased postural stability in those with CAI. Identifying the relevance between reduced lumbopelvic function and impaired sensory-perceptual outcomes might direct clinicians to novel methods for CAI patients to improve postural control ability and perceived ankle function. Therefore, the aim of this study was to examine the relationship between tests of lumbopelvic function and PROs in individuals with CAI. Thirty-three individuals with CAI underwent assessment of transversus abdominis and lumbar multifidus muscle contractility using diagnostic ultrasound; lumbopelvic stability via the unilateral hip bridge, trunk flexion endurance, Biering-Sorensen, and side plank tests; and isometric hip extension, abduction, and external rotation strength via hand-held dynamometry. We assessed PROs including the Foot and Ankle Ability Measure (FAAM-ADL and FAAM-Sport), the Tampa Scale of Kinesiophobia-11 and Fear-Avoidance Beliefs Questionnaire, and the Self-Efficacy of Balance Scale. Pearson product moment correlations and Separate backward linear regression analyses were used to identify the relationship between lumbopelvic function and PROs’ scores. Alpha was set a priori at P2=0.20, P2=0.29, P
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The Effectiveness of a Nurse Practitioner (NP) Led Clinic for Heart Failure (HF) Patients Following Hospital Discharge in a Rural Community Setting
2021Tami Collins and Michelle Renaud
Purpose: To explore if patient participation in the NP led HF clinic may reduce 30-day HF readmissions while providing HF specific education, recognition of symptoms/ management, teaching self-care, while ensuring that continued follow up occurs.
Research Questions: 1) Is there a significant difference between readmission rates in patients followed in the HF clinic compared to general HF follow up? 2) Is there a significant difference in patient knowledge including HF symptoms, self-management for patients followed in the NP led HF clinic for a minimum of 30 days? 3) How satisfied are patients that followed in the NP led HF clinic for a minimum of 30 days?
Significance: May demonstrate how close follow up in a HF clinic could reduce HF readmissions. Other disciplines may understand the necessity of specialized follow up.
Methods: Clinic serving HF patients NEW to the clinic over the age of 18 years in the community recently discharged from the hospital. Patients discharged from the hospital are referred by the hospital team and followed for a minimum of 30 days post discharge. Pre/ post education, satisfaction surveys utilized. Readmission rates reviewed retrospectively.
Findings: • Analyzed by descriptive statistics, frequencies, means, sums, percent’s, T tests conducted on variables of interest.
• Readmission rate of patients seen in the HF clinic within 14 days of discharge had lower readmission rates than those not seen in that timeframe.
• Significant increase in knowledge from pretest to posttest.
• Patients are satisfied with the care they receive in the HF clinic.
Discussion: Close follow up in a NP led HF clinic contributes to the reduction on HF readmissions.
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Defining the Environmental Niche of the Two Main Clades of Trichodesmium: A Study on the West Florida Shelf
2021Kristina Confesor, Corday Selden, Kimberly Powell, Angela Knapp, Kristen Buck, Laura Donahue, and Dreux Chappell
Dinitrogen (N2) fixation is the process of taking widely abundant but mostly biologically inaccessible N2 gas and converting it into more biologically accessible forms of the essential macronutrient nitrogen. Only a small fraction of organisms known as diazotrophs can perform biological N2 fixation. Trichodesmium is one such genus of N2-fixing marine cyanobacteria that is commonly observed in waters along the West Florida Shelf (WFS). We hypothesize that the two main Trichodesmium clades (T. erythraeum and T. thiebautii) occupy distinct environmental niches, one being more coastal and one being more oceanic. To test this hypothesis, we quantified gene abundance of both clades and compared the results with hydrographic data to distinguish any trends in niche distribution in samples collected on the WFS from three separate cruises. T. thiebautii abundance was higher further from the coast (at stations with greater bottom depths) and the T. erythraeum abundance was higher closer to the coast (at stations with lower bottom depths). A lack of nearshore sampling in 2015 initially made it difficult to conclusively identify trends in niche distribution, however with the addition of 2018 and 2019 samples, we observed a consistent coastal vs. open ocean niche separation for the two clades. In addition, T.thiebautii abundance was also significantly positively correlated with salinity. While previous work has found T. thiebautii is more abundant than T. erythraeum in open ocean surface waters, this is the first study to examine Trichodesmium clade abundance in a near-shore environment.
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Seasonal Variability in Diazotroph Abundance and Gene Expression at a Coastal N2 Fixation Hotspot (Outer Banks, NC)
2021Katherine Crider, Corday Selden, Kimberly Powell, and P. Dreux Chappell
Marine microbial dinitrogen (N2) fixation, the conversion of gaseous N2 to bioavailable species, is the primary source of new oceanic nitrogen (N). N is present in nucleic acids, amino acids, and proteins, and is essential to all life. Long considered to be a primarily oligotrophic ocean process, significant N2 fixation rates have recently been observed in coastal environments, including along the Cape Hatteras front. To see if elevated N2 fixation was a persistent feature in this region, N2 fixation rates and N2 fixer (diazotroph) abundance and gene expression were investigated through roughly monthly sampling at a field station (Jennette’s Pier) in the Outer Banks, NC, from June 2019 to August 2020, as well as a day-long cruise around the pier in August of 2019. In addition to rate and molecular samples, chlorophyll, and particulate N samples were collected and salinity/temperature profiles were measured. Using quantitative polymerase chain reaction techniques, we investigated the abundance and gene expression of diazotrophic (N2 fixing) cyanobacteria possibly responsible for these high coastal rates, and compared these results to N2 fixation rates measured using a variant of the 15N2 tracer assay. Diazotroph species investigated include Trichodesmium spp. and 5 endosymbiont cyanobacteria. Preliminary results suggest evidence of Gulf Stream intrusions within 300m from the shore, and a seasonal variability pattern of nitrogen fixation rates. This study provides useful measurements of coastal N inputs in the context of the global ocean N cycle and budget, and explores chemical and physical factors that affect these processes.
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Institutional Context Drives Mobility: A Comprehensive Analysis of Academic and Economic Factors that Influence International Student Enrollment at United States Higher Education Institutions
2021Natalie Cruz
International student enrollment (ISE) has become a hallmark of world-class higher education institutions (HEIs). Although the U.S. has welcomed the largest numbers of international students since the 1950s, ISE shrunk by 10% in the previous three years from an all-time high of 903,127 students in 2016/2017 (IIE, 2019). Research studies about international student mobility and enrollment highlights the significant role that academic and economic rationales play for international students. This quantitative, ex post facto study focused on the influence of ranking, tuition, Optional Practical Training, Gross Domestic Product, and the unemployment rate on ISE at 2,884 U.S. HEIs from 2008 to 2019 through the examination of four research questions. Data were analyzed for two longitudinal research questions using time series regression, particularly an Arellano-Bond estimator for an autoregressive distributed lag model. Linear OLS regression was used for the remaining two research questions which analyzed the variables for the 2018/2019 academic year, including OPT. Data were also analyzed using Carnegie classification (CC) as a grouping variable.
Results included that tuition was an important predictor of ISE, but it looked differently for different types of institutions. Higher ranking connected with higher ISE at doctoral institutions, but it was a deterrent at other institutions in the longitudinal analysis. This novel analysis of OPT showed that the number of students utilizing OPT was related to ISE, particularly at non-doctoral institutions. The findings were inconclusive about the influence of economic factors, as there were significant opposing findings in the different lags over time. This study also provided evidence that an urban location is important for ISE. Implications include the importance of advocating for sustainable federal immigration and employment policies, that context and institutional type influence ISE trends, and HEIs should better support international students in the United States to meet their career goals.
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Alexandrium in the Arctic: Are Harmful Algae Spreading as the Arctic Warms?
2021Sveinn Einarsson, Kate Lowry, Robert Pickart, Karin Ashjian, and P. Dreux Chappell
Alexandrium tamerense is a well-studied dinoflagellate known for its ability to produce the neurotoxin that causes paralytic shellfish poisoning. Until 1970 Alexandrium tamerense was only found in Europe, North America, and Japan but has been increasingly found all over the globe. Alexandrium is characteristically found in temperate and subtropical regions and as the Arctic warms, there is considerable concern that it may be expanding into the Arctic. We found Alexandrium tamerense during a research expedition to the Alaskan Beaufort Sea shelf to study upwelling. Upwelling events are known to support seasonal blooms of phytoplankton, which are important primary producers at the base of the oceanic food web. The Beaufort Sea in the Arctic Ocean is known to experience upwelling due to storms caused by atmospheric pressure differences between air masses over Canada and Alaska. This upwelling is becoming more frequent as sea ice melts and the Arctic becomes warmer. We examined the upwelling system in the Beaufort Sea during one of these storms, by collecting surface water samples before, during, and after an upwelling event. Here we present observations of Alexandrium tamarense, found before upwelling occurred, using three different methods.
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Preparing Counselors in Training to Work within Interdisciplinary Settings: What Are Supervisee’s Needs from Supervision
2021Jeanel Franklin and Suelle Micallef Marmara
Counselors are increasingly required to work in diverse and multicultural settings and within interprofessional and multi-professional teams (Schmit et al., 2018). For counselors to work effectively with professionals from other disciplines, they need training in collaborative competencies that include knowledge of each professions’ roles, responsibilities, and expertise (Arthur & Russell-Mayhew, 2010). Arthur and Russell-Mayhew identified supervision as possible leverage to support counselors in acquiring competencies to learn with and from other disciplines. However, there is limited research on how supervision supports health professionals, particularly counselors, in an interdisciplinary team (Owens et al., 1999). Therefore, the purpose of this study is to explore the perceived supervision needs of counselors in training (CITs) working in interprofessional settings to contribute to the gap in the literature.
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A Direct Method for Modeling and Simulations of Elliptic and Parabolic Interface Problems
2021Kumudu Gamage and Yan Peng
Interface problems have many applications in fluid dynamics, molecular biology, electromagnetism, material science, heat distribution in engines, and hyperthermia treatment of cancer. Mathematically, interface problems commonly lead to partial differential equations (PDE) whose in- put data are discontinuous or singular across the interfaces in the solution domain. Many standard numerical methods designed for smooth solutions poorly work for interface problems as solutions of the interface problems are mostly non-smoothness or discontinuous. Moving interface problems depends on the accuracy of the gradient of the solution at the interface. Therefore, it became essential to derive a method for interface problems that gives second-order accuracy for both the solution and its gradients. As most applications in the real world are in 3D settings, the development of three-dimensional elliptic interface solvers and the study of their convergence is significant. We have developed a novel Direct Method for solving three-dimensional elliptic interface problems that preserve the discontinues in solution and gradient across the interface. The method uses a standard seven-point central difference scheme at regular grid points and a compact twenty-seven-point scheme only at irregular grid points by incorporating the interface's jump conditions. The model was implemented using both MATLAB and FORTRAN routines and showed that the computed solution and gradient of the solution near the interface are second-order accurate in infinity norm. We also have modified the developed direct method to solve the 3D heat equation with fixed interfaces. Numerical results showed that the proposed method is unconditionally stable and is second-order accurate in both time and space.
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3D LIDAR Human Skeleton Estimation for Long Range Identification
2021Alexander Glandon, Lasitha Vidyaratne, Nasrin Sadeghzadehyazdi, Nibir Dhar, Jide Familoni, Scott Acton, and Khan Iftekharuddin
This research project is the continuation of an effort by the Vision Lab to understand human gait and motion using special-purpose imaging sensors and novel computer vision algorithms. The project began using a Motion Capture (MoCap) system which measures 3D human skeleton information in real-time by attaching markers to a human subject and viewing the human motion with a set of cameras at different angles. We developed an algorithm to determine the gender of a subject wearing these sensors. The current phase of this project extends this work using a state-of-the-art flash Lidar sensor. This sensor scans the surface of objects and gives a 3D depth map of the object in real-time. We developed a computer vision system that can estimate a human skeleton from Lidar data, which resembles the MoCap data format. Using these computed 3D skeletons we can perform human identification. The poster outlines the current Lidar-based algorithm using a flow chart to explain the input and output for each component of the system and how each data modality is used to build the final skeleton. The poster compares performance for our human identification with other methods for human- identification using 3D sensors. Finally, future work using infrared sensing is discussed.
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Predictors and Characteristics of AAC Service Delivery Among Post-Professional Speech-Language Pathologists
2021Meredith Gohsman and Rachel Johnson
In the United States, approximately four million individuals are unable to use verbal speech to meet communication needs (Beukelman & Mirenda, 2013). Augmentative and alternative communication (AAC) modalities support the needs of these individuals, offering temporary or permanent solutions to meet an individual’s communication needs across environments (Beukelman & Mirenda, 2013). Tasked with the use of AAC to support individuals with communication impairments, speech-language pathologists are directly involved in AAC service provision (American Speech-Language-Hearing Association, 2016). Past research has identified barriers to AAC service provision and use of AAC modalities, including lack of perceived competence, time, financial support, and availability of aided AAC modalities (e.g., Bailey et al., 2006; Costigan & Light, 2010; Iacono & Cameron, 2009; Marvin et al., 2003, Soto et al., 2001). This study surveyed post-professional speech-language pathologists to examine 1) characteristics of perceived competence and use of AAC during service delivery, 2) perceived barriers to AAC service delivery, and 3) learning preferences for AAC-related training.
Five-hundred thirty post-professional speech-language pathologists in the United States participated in this study. To address the research questions, regression analyses were used with a two-step hierarchical method of entry. Step one included predictor variables related to the individual, and step two included predictor variables related to the clinical practice setting. Results revealed speech-language pathologists’ perceived competence, use of AAC modalities, barriers to AAC service delivery, and learning preferences are predominantly influenced by both individual and practice setting characteristics. These results suggest preservice coursework alone does not adequately address speech-language pathologists’ needs for AAC service delivery. Graduate programs must integrate hands-on training experiences to develop students’ competence related to AAC. For post-professionals, effective AAC-related training must be tailored to reflect speech-language pathologists’ specific practice settings, clinical populations, and learning preferences.
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Self-Selected Maximum but Not Jogging Speed Decreases with Age in Male and Female Runners
2021Heather Hamilton and Rumit Singh Kakar
Introduction: Running velocity decreases with age, likely resulting from physiological and musculoskeletal changes associated with aging. Females experience a more rapid decline in physical performance during middle age than males, therefore it is important to consider separate-sex analyses when studying running biomechanics and running-related injury. The purpose of this study was to determine the relationship between age and different running speeds separately for female and male runners.
Methods: Male (n=33) and female (n=46) runners (ages 18–65 years) ran at their self-selected JOG (long distance) and MAX (maximal running) pace on a treadmill. Running velocity was recorded. Simple linear regression was used to assess the relationship between age and running velocity at JOG and MAX speeds separately for males and females. Percent decrease in running speed with age was calculated.
Results:There was a significant negative correlation with age and MAX speed for males (p=.034, R=.37) and females (p
Discussion: Maximal running speed places a greater physical demand on the runner and appears to be more indicative of changes in running biomechanics associated with aging. Despite a lack of significant age and sex interaction effect on running speed, females demonstrated a greater percent decrease in maximal speed with age compared to males. Sex differences in biomechanics of aging runners should be further explored. Because running has several health advantages, it is important to understand biomechanical changes in aging runners to maximize running ability and reduce running-related injury.
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Musculoskeletal Modeling of the Pelvis and Lumbar Spine During Running
2021Ruth Higgins, Maryam Moeini, Hunter Bennett, and Stacie Ringleb
Musculoskeletal modeling provides an alternative to in-vivo characteristics that are difficult to directly measure for movements such as running, especially for trunk muscles and joints. The full-body-lumbar-spine (FBLS) model by Raabe and Chaudhari, 2016 is an OpenSim model created for simulations of jogging. The lifting full-body (LFB) model by Beaucage-Gauvreau et al., 2018 is an adaptation of the FBLS created for estimating spinal loads during lifting. PURPOSE: Determine validity of the FBLS and LFB models in simulating pelvis and lumbar spine kinematics during running. METHODS: Inverse Kinematics were executed using experimental data for the FBLS and LFB models. To obtain the 3D motion data, 5 runners ran on a treadmill at self-selected jogging pace (2.6±0.2 m/s). Axial rotations at the pelvis segment and for the sum of lumbar motion (L1-L5 intervertebral disc joints) were calculated from marker data, and the range of motion (ROM) averaged for the experimental data and each computational model. RESULTS: FBLS and LFB models had the same relative movement patterns as the experimental data. However, the ROM for both models differed from the human data. For the experimental data, the average ROM was 33.6 ± 15.6° for total lumbar rotation and 24.7 ± 12.3° at the pelvis. The ROM for the pelvis was 17.97±6.87° and 19.22±7.63° for the LFB and FBLS models, respectively. The lumbar ROM was 29.53±5.46° and 18.39±10.56° for the LFB and FBLS models, respectively. The differences in ROM could be because the experimental data used a multi-segmented torso and a rigid lumbar spine marker model, whereas the OpenSim models utilized a rigid torso (lumped thoracic and cervical vertebrae, ribcage, scapulae, and head) with a coupled lumbar spine. The average maximum RMS across all participants was 0.05 ± 0.004 cm for both LFB and FBLS models. CONCLUSION: The LFB model was created for lifting simulations but provides a better simulation of running motion at the lumbar and pelvis than the FBLS model, potentially due to the LFB model having a 3-DOF joint at T12/L1 and linear kinematic coupling constraints to distribute the net trunk motion across the six intervertebral joints (T12-L5). The ROM differences at the L5/S1 could potentially be corrected with a multi-segmented torso model. Both models have potential for simulating axial rotation of the pelvis and lumbar spine during running.
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Using Machine Learning to Quantify Transverse Plane Lumbopelvic Rhythm
2021Seth Higgins, Joshua Tome, and Rumit Singh Kakar
Lumbopelvic rhythm illustrates the relative motion between the lumbar spine and pelvis during various activities and could be used as a biomarker for low back pain (LBP). Sagittal plane lumbopelvic rhythm has been extensively examined as a surrogate to measure low back pain risk factor, but trunk rotation, the second component of lifting is commonly missed. Since lumbopelvic rhythm are time series and not discrete variables, machine learning may be a viable solution in identifying clusters of patterns for healthy adults. PURPOSE: To categorize healthy lumbopelvic rhythm in the transverse plane using machine learning. METHODS: 80 adults with no history of LBP (Young: n = 46; 26.9 ± 6.9 yr; Middle-Age: n = 33; 52.4 ± 6.9 yr). 3D kinematics of the lumbar spine and pelvis were calculated as participants performed maximal trunk rotation from right to left. Coupling angles were calculated using vector coding and represented in 4 coordination patterns (in-phase, anti-phase, superior-only, inferior-only). K-means clustering (k = 3) was used to segment coupling angles into clusters. Within each cluster, the age groups were compared. RESULTS: 3 distinct movement patterns were discovered (Figure 1). Lumbar spine and pelvis mostly moved in-phase, but for cluster 1, the start and end of the lumbar and pelvis was in anti-phase, while cluster 2 and 3 started and ended in-phase. Cluster 2 switched from in- to anti- and back to in-phase in the start and during transitioning directions. Age differences were seen only in cluster 1 where young and middle-age adults started rotation in anti-phase, but middle-age adults ended the rotation by only moving the lumbar spine and young adults ended in anti-phase. CONCLUSION: These movement patterns represent the different ways a healthy individual may perform trunk rotation, which along with sagittal plane motion can potentially be used to identify individuals with LBP.
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The Evacuation Behaviors and Risk Perceptions of College Students in Coastal Communities
2021Saige Hill and Wie Yusuf
Effective emergency management saves lives. The role of an emergency manager is to implement policies and practices to ensure disaster preparedness, mitigation, response, and recovery to promote community resilience; however, there are many factors that may hinder goal achievement. The False Alarm and Desensitization Model explores this concept by illustrating how evacuation behaviors and risk perceptions are influenced by individual experiences. Specifically, the Model demonstrates how disaster event false alarms and desensitization decrease the likelihood of adequate response during subsequent events.
False alarms and desensitization impede disaster preparation and perpetuate community vulnerability. This research highlights the false alarm theory of neurology and desensitization theory as applied to media and how they contribute to the two components of the False Alarm and Desensitization Model. The poster introduces the Model and key study, an analysis of the evacuation behaviors and risk perceptions of college students, considering the implications of false alarms and desensitization.
The False Alarm and Desensitization Model attempts to explain the relationship between false alarms, desensitization, and community vulnerability. College students serve as one of the most vulnerable populations when presented with natural and manmade disasters. Based on studying away from home, deciding to evacuate or shelter based on their own perceptions, having limited support and resources, and other factors, students are at great risk. Furthermore, college students in coastal communities are exposed to unique threats such as hurricanes and severe flooding, and COVID-19 has exacerbated their vulnerability.
This research addresses an urgent need. Vulnerable populations such as college students are disproportionately affected by disasters, so studying this population and ensuring that school administration and students are adequately educated on current research will promote better disaster outcomes.
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