Now showing items 21-40 of 93517

    • Nonlinear ultrasonics-based technique for monitoring damage progression in reinforced concrete structures

      Basu, Sukanya; Thirumalaiselvi, A.; Sasmal, Saptarshi; Kundu, Tribikram; Civil and Architectural Engineering and Mechanics, University of Arizona (Elsevier BV, 2021-08)
      In reinforced concrete (RC), material nonlinearity is evident even in its undamaged state due to the inherent microstructure. In the present work, damage progression in RC structure at different levels of damage is investigated using linear and nonlinear ultrasonic techniques. The primary focus of this study is to monitor the structure from its initiation stage(s) of damage to advanced stages. Ultrasonic velocity tomography is first implemented to identify the weaker regions and map any damage occurring at various levels of loading. Two critical regions are identified from ultrasonic tomography and further damage characterization is carried out using various ultrasonic techniques to quantitatively assess the progression of damage in these two regions. The linear ultrasonic techniques such as time-of-flight (TOF) and attenuation, and the nonlinear ultrasonic techniques such as sub- and super- harmonic, energy distribution, etc. are employed to detect the damage progression. It is found that the changes in linear parameters due to damage progression in RC structure are often insignificant and inconsistent. However, some of the nonlinear ultrasonics-based techniques are found to be very efficient to monitor the damage progression. A relatively new and promising nonlinear ultrasonic technique, namely the sideband peak count-index (or SPC-I) provides a very clear and consistent indication of damage at the early stage. The present study shows that during the initial stages of damage, SPC-I based nonlinear technique performs significantly better (at both regions as identified through ultrasonic tomography) than other linear and nonlinear techniques, whereas at higher damage stage the superiority of this nonlinear ultrasonic technique slowly diminishes. The present study also shows that out of all nonlinear ultrasonics-based techniques considered here, SPC-I technique provides the highest sensitivity to the damage progression and can be effectively used as a very robust nonlinear ultrasonic tool for identifying the onset and progression of damage in RC structures. © 2021 Elsevier B.V.
    • Targeting NRF2 to treat cancer

      Sivinski, Jared; Zhang, Donna D.; Chapman, Eli; Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona (Elsevier BV, 2021-06)
      NRF2 is a basic leucine zipper (bZip) transcription factor that is the master regulator of redox homeostasis. Under basal conditions, the cellular level of NRF2 is low due to a posttranslational regulation by the ubiquitin proteasome system (UPS). But, when an organism is challenged with oxidative or xenobiotic stress, the NRF2 pathway is activated by inhibition of the E3 ubiquitin ligase complex that normally marks NRF2 for destruction. For several decades, researchers have searched for molecules that can intentionally activate NRF2, as this was shown to be a means to prevent certain diseases, at least in animal models. In the present era, there are many compounds known to activate the NRF2 pathway including natural products and synthetic compounds, covalent and non-covalent compounds, and others. However, it was also revealed that like many protective pathways, the NRF2 pathway has a dark side. Just as NRF2 can protect normal cells from damage, it can protect malignant cells from damage. As cells transform, they are exposed to many stressors and aberrant upregulation of NRF2 can facilitate transformation and it can help cancer cells to grow, to spread, and to resist treatment. For this reason, researchers are also interested in the discovery and development of NRF2 inhibitors. In the present review, we will begin with a general discussion of NRF2 structure and function, we will discuss the latest in NRF2 non-covalent activators, and we will discuss the current state of NRF2 inhibitors. © 2021 Elsevier Ltd
    • Testing a Low Cost Apparatus to Monitor Soil Salinity in Plant Physiology Experiment Using Arduino Platform

      Negrão-Rodrigues, Vanessa; Teodoro, Grazielle Sales; Marques-Azevedo, Mario J.; Brum, Mauro; Department of Ecology and Evolutionary Biology, University of Arizona (Informa UK Limited, 2021-05-13)
      Soil salinization is a common problem impacting plant physiology and agricultural productivities. In order to monitor soil salinization in plant physiological experiments, a salinity monitoring system–SProb–was produced to improve our understanding of plant responses to salinity, using open hardware Arduino platform. An experiment was performed and designed to calibrate and check the viability and accuracy of SProb to be used in scientific researches. Salt concentrations were manipulated to identify sensor ability in determining salt accumulation or leaching in soils. Also, two mangrove plant species were grown to identify if root presence would affect soil salt measurements. The soil osmotic potential (Ψs) was estimated from SProb results and correlated with predawn and midday leaf water potential (Ψl) of the mangrove plants, to identify if Ψs would affect plants water regulations. It was also shown that SProb described well the soil salt accumulation or leaching along the time, and the measurements were not affected by the presence of roots. The ranges of Ψs matched with the range of mangrove Ψl, and the Ψl decreased with the decrease in Ψs (increase in salinity). It was confirmed that the SProb sensor is efficient, cheap and has enough accuracy to monitor soil salt concentration. Thus, SProb can be used in plant physiological experiments increasing our ability to make accurate science when such technology is not available in research centers. © 2021 Taylor & Francis Group, LLC.
    • Outdoor/Indoor Contaminant Transport by Atmospheric Dust and Aerosol at an Active Smelter Site

      Rodríguez-Chávez, Tania B.; Rine, Kyle P.; Almusawi, Reman M.; O’Brien-Metzger, Ruby; Ramírez-Andreotta, Mónica; Betterton, Eric A.; Sáez, A. Eduardo; Department of Chemical and Environmental Engineering, The University of Arizona; Department of Hydrology and Atmospheric Sciences, The University of Arizona (Springer Science and Business Media LLC, 2021-05-22)
      Activities associated with mining operations including smelting, ore handling, and mine tailings management have been identified as sources of dust and aerosol that may contain metal and metalloid contaminants, such as lead (Pb) and arsenic (As). Previous studies on contaminant transport have concentrated on the potential impact of these particulate emissions in outdoor environments. The purposes of this study were (i) to quantify the effect of dust and aerosol particle size on contaminant transport from outdoor-to-indoor environments and (ii) to document the changes in particle chemical composition during transport through the outdoor/indoor barrier. Outdoor and indoor particulate samples were collected at a high school equipped with mechanical air filtration systems from 2016 to 2019. The school is located near a set of mine tailings and an active copper smelter in Hayden, Arizona. Particle size segregated samples were collected using a ten-stage micro-orifice uniform deposit impactor (MOUDI). Results show that airborne fine particles (aerodynamic diameters less than 1 micron) can penetrate to the indoor environment but in a reduced amount due to mechanical filtration. Aerosol in the fine fraction particulate air concentrations was around 50% of the corresponding outdoor values, but their mass concentration of contaminants was similar to outdoor values. Indoor coarse particles (> 1 micron) comprised close to 20% of the levels found in outdoor coarse particles. These results highlight the need to consider the impact of particle diameter when assessing indoor exposure and potential health effects in communities living under the direct influence of mining and smelter activities. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
    • Elementary Science Teachers Noticing, Interpreting, and Responding: Students' Science Toolkits for Sensemaking

      Gunckel, Kristin L.; Cooper-Wagoner, Judith Ann; Turner, Erin E.; Clift, Renée T. (The University of Arizona., 2021)
      This study examined the ways in which elementary science teachers notice, interpret and respond to students’ sensemaking resources that students bring to school in the form of science toolkits. The science toolkits are comprised of three sensemaking resources: 1) ideas; 2) out-of-school experiences and funds of knowledge, and 3) youth genre. The high-leverage practices, noticing, interpreting, and responding, are effective teaching practices for advancing student learning. When employed proficiently, teachers’ noticing, interpreting, and responding to students’ science toolkits leverages sensemaking in learning science. A constant comparative analysis was employed in this qualitative study to compare the similarities and differences of four teacher groups’ noticing, interpreting, and responding to students’ science toolkits at different points along their pathway in a learning-to-teach science trajectory. The four teacher groups attended and graduated from the same teacher preparation program. The groups included aspiring teachers who had just begun a teacher preparation program, practicing teachers who had recently completed the science methods course, student teachers who in addition to completing the science methods course were placed in student teaching, and practicing teachers who were in their third to fifth year with planning and teaching science. The findings showed how the four teachers demonstrated growing sophistication in their strength-based noticing, interpreting, and responding to students’ science toolkits. The aspiring teachers valued all students’ sensemaking resources and therefore found them all worth responding to. The preservice teachers recognized science concepts in individual students’ resources that the students used for making sense of science and leveraged students’ resources for further science understanding. The student teachers were aware of how individual resources contributed to collective group sensemaking of science and utilized collective understanding to facilitate the advancement of students’ deeper understanding of science. The practicing teachers recognized how individual students’ resources supported smaller aspects of science concepts that fit together into a bigger science idea and responded to the smaller aspects of science thinking in students’ resources to assist students in connecting the smaller concepts to the big science idea. Understanding the growing sophistication of these four teacher groups’ noticing, interpreting, and responding to students’ science toolkits for sensemaking when learning science provides insights to the varied ways that the teacher groups demonstrated these practices as they grew in sophistication. This research also holds potential to inform teacher educators with approaches to leverage preservice teachers’ strength-based interpretations of students’ sensemaking resources toward more sophisticated noticing, interpreting, and responding to students’ science toolkits for learning science. 
    • Proposed Use of Podcast as a Medium for Aural Rehabilitation with Post-Lingually Deafened Adults who Use Cochlear Implants

      Deruiter, Mark; Fuggiti, Jessica Kelly; Norrix, Linda; Shaw, Linda; Hansen, Erica (The University of Arizona., 2021)
      For post-lingually deafened adults who have undergone cochlear implantation, listening to acoustically rich environments, and undergoing aural rehabilitation can be critical in adapting to listening through the altered acoustic signal of their processor. Despite the availability of at-home aural rehabilitation tools, there are still barriers to receiving effective aural rehabilitation. Podcasting is one form of aural rehabilitation that has yet to be developed or researched in audiology. This project considers the potential efficacy of podcast as an aural rehabilitation tool and provides scripts for a future podcast series to be recorded and distributed at the University of Arizona Hearing Clinic. The episodes are designed to be listened to by post-lingually deafened adults after their audiology follow-up appointments for the first six months post-implantation. Perceptual training experiences and counseling are incorporated into the podcast to increase engagement with the listener. Communication partners are encouraged to partake in this aural rehabilitation tool as they can provide valuable feedback and encouragement. In conjunction with appropriate follow-up appointments with a professional, the use of podcasts can provide additional aural rehabilitation to help cochlear implant patients reach their communication goals.
    • Examining Pathways to Hearing Screenings in Geriatric Primary Care Practice

      DeRuiter, Mark; Marrone, Nicole; Sulahria, Amber Jahan; Fabiano-Smith, Leah; Wong, Aileen (The University of Arizona., 2021)
      Complex problems rarely have simple solutions. As we consider aging adults and their approaches to treatment for hearing loss, we find there are a variety of factors that play a role in how a patient approaches hearing health care, much less how they engage with these services. The purpose of this literature review is to create a better understanding of factors impacting geriatric patients and access pathways to hearing health care. Specifically, this paper will address patient pathways to hearing and hearing health care services via primary care practitioners (PCPs) and Medicare coverage as the two primary gate keepers in accessing these services within the older population. Medical education curricula are reviewed, theoretical models and frameworks are discussed, as well as consideration of systematic barriers to care identified through literature review. This paper concludes with recommendations for improving access to hearing health care via PCPs and Medicare coverage for the older adult patient population.
    • Impact of Audiology Assistants

      DeRuiter, Mark; Shi, Jennifer; Muller, Thomas; Samlan, Robin; Schultz, Jared (The University of Arizona., 2021)
      The use of assistants has been widely adopted across multiple disciplines such as speech-language pathology, occupational therapy, and physical therapy. There is growing interest in exploring the role of audiology assistants across various practice environments. An overall national shortage of audiologists combined with an increased demand for audiologic services has progressively encouraged the profession to move toward greater efficiencies of care through an audiology assistant model (Bloom, 2009). Much is unknown about the audiology assistant model including the scope of practice and training that is necessary, however. Currently, the assistant model differs across states as well as medical institutions and private practices. The proposed work will have two parts. First, a thorough literature review of relevant research will be conducted and compared with what is assumed about the practice of assistants in healthcare. Second, a business process analysis will be conducted to review an assistant model within a higher education clinic at the University of Arizona. The business process analysis will review the financial and potential scheduling impacts of the hearing clinic before and after the employment of a single audiology assistant. The analysis will review data specifically examining whether having an assistant alleviates the audiologist’s time from performing routine tasks, in exchange for practicing at the top of their license by attending to patients with more complex appointments. Appointment types across the years 2016-2019 will be examined, assuming the appointments requiring more simple tasks will be allocated to the audiology assistant. A high-level revenue analysis of the clinic will be completed and reviewed to reflect the charges within the given time period selected. An increased level of delegation has been adopted in other healthcare fields with increasing employment rates of assistants across various disciplines, therefore the potential benefits of a similar position in the field of audiology could be positive.
    • Stage of Change Related to Appointment Type

      Marrone, Nicole; Deruiter , Mark; Leedy, Emily; Shaw, Linda; Barakat, Fadyeh; Norrix , Linda (The University of Arizona., 2021)
      The transtheoretical model of behavior change has been adapted for a variety of different health behavior changes. In audiology, the transtheoretical model has been adapted for the readiness to pursue amplification. An audiologist can use the transtheoretical model of behavior change as a counseling tool for patients. There are five stages of change: pre-contemplation, contemplation, preparation, action, and maintenance. Previous research conducted outside the United States has focused on the patient’s stage of change at the initial appointment with an audiologist. The objective of the current study is to assess the stage of change that patients are in across different types of audiology appointments. There were 50 participants recruited at the University of Arizona Speech and Hearing Clinic. Participants completed an anonymous survey that included two different stage-of-change questionnaires: The Staging Algorithm, and the Line. Additional questions were asked that focused on a participant’s personal experience with hearing loss and use of hearing aids. The results of this study showed that the majority of participants were in the maintenance stage of change across multiple types of appointments. However, for any given appointment type, there was variation in the stage-of-change reported and a wide range of scores in self-reported importance of improving hearing and motivation. Based on these findings, it is suggested that the clinical use of The Staging Algorithm and The Line can help audiologists guide the appointment based on a person’s stage of change.
    • Matched Versus Unmatched Functional Requests Within the Negative Reinforcement Paradigm: An MO Analysis

      Umbreit , John; Carr, Chelsea E.; Gardner , Andrew W.; Liaupsin , Carl; Hartzell, Rebecca (The University of Arizona., 2021)
      In the current study, we conducted a brief assessment within a multielement design to identify motivating operations (MOs) that increased or decreased the value of negative reinforcement for children with a history of challenging behavior when presented with tasks or demands. For three of the four participants, we identified specific MOs that increased the value of negative reinforcement in the form of escape from nonpreferred tasks. The results demonstrated that the demands themselves were not aversive; rather particular dimensions of the demand (e.g., difficulty, amount). The fourth participant engaged in challenging behavior regardless of the MOs present, which suggested that the demands were aversive to him. Based on the results of the assessment of MOs, each participant was provided an individualized mand to use that abolished the value of negative reinforcement. The mands were provided on picture cards and the contingencies of reinforcement were explained to the participants. Within a reversal design, we then assessed the reinforcers associated with the mand to show their relation to challenging behavior. The individualized mands had the same abolishing effect across all participants, thus showing that the assessment had identified functionally relevant MOs for each participant. Additionally, there was an increase in task engagement, task completion, and accuracy for all participants when matched mands were utilized.
    • The Effect of Age-Related Hearing Loss on Perception of Age-Related Dysphonia

      Samlan, Robin; Turner, Melanie; Story, Brad; Bunton, Kate (The University of Arizona., 2021)
      The purpose of this study was to investigate the impact of different degrees of sensory and metabolic-sensory hearing loss on the perception of breathiness, roughness, and strain in aging voices. Four voices identified as normal, breathy, rough/strained, and rough by an expert panel were filtered through the HELPSV2 (Sensimetrics Corporation, Gloucester, MA) hearing loss simulator to create seven distinct hearing patterns per sample. Descriptive acoustic analysis was conducted to examine differences in spectrograms, long-term average spectra (LTAS) and smoothed cepstral peak prominence (CPPS) across voice and hearing loss profiles. Twenty naïve listeners judged the voice quality of each of 28 unique samples on a visual analog scale anchored with the labels “terrible voice quality” and “excellent voice quality.” Data were analyzed using a General Linear Mixed Model (GLMM) and post-hoc comparisons of significant findings. We did not find significant differences in perceptual ratings across any degree of sensory or metabolic-sensory hearing loss for breathy, rough/strained, or rough voices. Metabolic-sensory hearing loss resulted in significantly poorer perceived voice quality than sensory hearing loss for the normal voice, although degree of hearing loss did not significantly impact ratings. These findings provide preliminary evidence that metabolic-sensory age-related hearing loss may distort perception of voice quality, potentially due to a relative reduction in amplitude of harmonic energy in the sample. Future research with larger listener pools is required to further investigate these relationships.
    • An Assessment of Telecoil Benefit: A Pilot Study

      Marrone, Nicole; Beatty, Sarah; Dai, Huanping; Norrix, Linda; Wong, Aileen; Shaw, Linda (The University of Arizona., 2021)
      Patients with hearing loss often experience a decreased signal-to-noise ratio (SNR), resulting in an increased difficulty to understand speech in noise, which can negatively impact their quality of life (Dillon, 2012). An induction loop or hearing loop is one type of assistive listening system that improves the signal to noise ratio at the ear level of the user by using an electromagnetic field. Hearing loops are commonly preferred by patients as they do not require the use of any additional device. However, there is currently limited research supporting the benefit of using hearing loops/telecoils in a classroom setting. The purpose of this audiology doctoral project was to measure the benefits of looping in a university classroom under ecological conditions for adults with hearing loss. This project was separated into three phases. The first phase was comprised of verifying a university classroom loop (installed in Speech-Language and Hearing Sciences Building, room 409, summer 2019) to international quality standards (IEC 60118-4). The second phase included facilitating two focus groups with the local hearing loss support group. Using the approach of patient-centered outcomes research, the third phase included subjective and behavioral assessments in a looped classroom. Results revealed that, on average, participants had better speech perception scores as measured by the AZBio sentences in the t-coil conditions than in the non-t-coil conditions. Additionally, participants, on average, reported reduced temporal demand and increased performance when using the t-coil as measured by the NASA Task Load Index.
    • Effective Supports and Experiences That Advance Inclusive Postsecondary Education for Students With Intellectual and Developmental Disabilities

      Antia, Shirin D.; Lansey, Kirsten Rebecca; MacFarland, Stephanie Z C; Liaupsin, Carl (The University of Arizona., 2021)
      Individuals with intellectual disabilities (ID) have the lowest rates of post-high school education and employment of all disability groups (Migliore, et al., 2009). Inequity in educational and employment outcomes is arguably a result of the scarce opportunities for students with intellectual and developmental disabilities (IDD) to attend college or obtain competitive employment (Grigal & Papay, 2018). Opportunities for students with IDD to attend inclusive postsecondary education (PSE) programs at colleges around the United States have gradually increased since the Higher Education Opportunity Act (P.L. 110-315) passed in 2008. PSE is associated with positive long-term outcomes of students with IDD, including increased competitive employment and self-determination (Moore & Schelling, 2018; Smith et al., 2018). The intent of this three-study dissertation was to identify effective supports and meaningful experiences that advance PSE opportunities for students with IDD. Peer mentors are college students that support PSE students with IDD to attend courses and complete assignments, develop employment skills, navigate campus, and socialize (Kleinert et al., 2012). Peer mentors reported needing training to support students to improve their social skills and increase their appropriate behavior (Giust & Valle-Riestra, 2017). The first two studies of this dissertation explored the impact of training and coaching on peer mentors’ implementation fidelity and generalization of students’ behavior plans. The first study used a nonconcurrent single-subject multiple baseline design across three peer mentor-student pairs to examine the impact of training and coaching with performance feedback on peer mentors’ fidelity in implementing function-based intervention plans (FBIP) for students with intellectual disability and autism spectrum disorder. All peer mentors improved their implementation fidelity immediately after being trained and further improved their fidelity after being coached. One to two coaching sessions were necessary for peer mentors to reach high levels of fidelity in implementing students’ FBIP. Students with IDD also increased prosocial behaviors when function-based support was implemented with fidelity. The second study used a single-subject multiple baseline design to examine the relationship between training and coaching with performance feedback on a postsecondary peer mentor’s implementation fidelity and generalization of a student’s FBIP across three settings. The peer mentor’s implementation fidelity immediately improved across all three settings after receiving initial training. Fidelity in each setting increased further following the coaching specific to that setting. The peer mentor generalized skills taught during coaching to two of the three settings. There was a functional relation between the peer mentor’s fidelity and the student’s on-task behavior in two of the three settings. For the final study in this dissertation, semi-structured interviews explored the perspectives of 10 current and recently graduated PSE students with IDD to understand the experiences and supports that contributed to progress towards their self-directed employment, education, and social goals. Students described internship experiences as fundamental to progress towards their employment goals. Internships led to students’ learning work skills and preferences, resulting in many students adjusting their employment goals during PSE. Peer mentor support was described as essential for advancing students’ goals in all areas. Students relayed that continuing to learn and developing friendships during PSE changed their future. Results from these studies identify effective experiences and supports that improve skill development and goal progression of PSE students with IDD. Additionally, results reinforce the importance of inclusive PSE options to increase equity in outcomes for individuals with IDD.
    • Chemicals of Emerging Concern Measured in Roof-Harvested Rainwater to Inform Environmental Justice Communities

      Ramirez-Andreotta, Monica D.; Villagómez-Márquez, Norma Nohemi; Abrell, Leif M.; Brusseau, Mark L.; Chorover, Jon (The University of Arizona., 2021)
      The unregulated development of various human activities such as industry, agriculture, and transport result in adverse environmental consequences. In the early 2000s, the global production of human-made chemicals was 400 million tons each year. Over 50% of these chemicals' total production is considered environmentally harmful compounds, and 70% of those chemicals have a significant environmental impact. Chemicals of emerging concern (CECs) encompass a wide range of human-made chemicals (such as pesticides, personal care products, industrial compounds, among others) used worldwide and indispensable for modern society. However, many of these chemicals have no enforced regulatory standard. In the last decade, CECs have been detected at low levels in the environment, including surface water, drinking water, soils, and precipitation rain and snow. CECs wide prevalence in the environment makes them potential candidates for future regulation depending on their toxicity and frequency of detection in the environment. Due to global water scarcity concerns and population growth, alternative water sources and conservation efforts are critical, especially in arid and semi-arid regions of the planet. The ancient practice of harvesting rainwater is becoming more common, and as this practice grows, so does interest in the quality of harvested rainwater. This thesis measured CECs in roof-harvested rainwater collected by citizen scientists over three years. The goal was to determine whether harvested rainwater is a viable method for community members to offset their dependence on existing water supplies. All measurements were below currently available U.S. Environmental Protection Agency Primary Drinking Water Standards. This finding indicates that the quality of the roof-harvested rainwater is viable for non-potable domestic use in Arizona communities. However, due to the nature of CECs, ecological and human health risk-based standards currently do not exist for all measured compounds for comparison. Due to these data and policy gaps, ongoing investigations, and efforts to protect water sources are essential.
    • Zinc Management and Salt Tolerance of Pecan in Arid Regions

      Walworth, James L.; Smith, Cyrus; Blankinship, Joseph C.; Heerema, Richard J. (The University of Arizona., 2021)
      In the alkaline, calcareous soils common to the southwest zinc reacts with hydroxyl and carbonate groups forming compounds of low solubility, reducing its plant availability, and making soil application of zinc oxide (ZnO) or zinc sulfate (ZnSO4) impractical. Therefore, foliar application of zinc in southwestern pecan orchards is common practice. Fertigation with zinc-ethylenediaminetetraacetic acid (Zn-EDTA) is a possible alternative that has shown positive results in alkaline, calcareous soils. However, many growers fertigating their orchards with Zn-EDTA are still using supplemental zinc foliar sprays due to lack of confidence that soil applied Zn-EDTA can supply enough zinc to the trees. We conducted an experiment to determine if the application of foliar zinc sprays to ‘Wichita’ pecan trees already receiving zinc in the form of Zn-EDTA through fertigation would increase photosynthesis rates. We applied zinc sulfate monohydrate (ZnSO4·H2O), ZnSO4·H2O + Urea Ammonium Nitrate (UAN), Zn-EDTA, water alone, and water + UAN to seven ‘Wichita’ pecans growing in alkaline, calcareous soil in San Simon, AZ. Applications were made twice in 2018 and twice in 2019, Zn-EDTA was applied only in 2019. Photosynthesis measurements were taken approximately two to four weeks following each application. Mid-day stem water potential was also measured to verify that water stress was not limiting photosynthesis. Our results showed that photosynthesis rates were not increased by the application of supplemental foliar zinc sprays in trees fertigated with Zn-EDTA with mean leaf zinc concentrations of untreated leaves in the range of 16-21 mg·kg-1. We concluded that photosynthesis was not zinc limited and that no additional benefit was conferred with regard to photosynthesis from the application of supplemental foliar zinc sprays.Another problem for pecan growers in the southwest is high salt content in the soil. Very little experimentation has been conducted to determine pecan response to saline-sodic conditions. To contribute to this research, we performed an experiment with seven rootstock pecan seedlings grown in alkaline, calcareous, saline-sodic soil at the Safford Agricultural Center in Safford, AZ. The seedlings were chosen from different geographic regions. While we only have knowledge of the maternal genetics of the seedlings which were grown from open-pollinated seed, we hypothesized that seedlings with origins in regions with lower precipitation would be more tolerant of the experimental conditions than those from regions with higher precipitation. It was determined that leaf sodium concentration was more strongly correlated with salt injury in the plants than chlorine. Leaf potassium:sodium (K:Na) ratio was strongly correlated with resistance to salt injury, tree growth rates, and vigor. In support of our hypothesis we found the maternal parentage of the most tolerant seedlings in our experiment was ‘Elliott’, a cultivar with likely Mexican origins (although the ‘Elliott’ cultivar was a seedling selection from Florida). ‘Elliott’ generally outperformed the other seedlings in visual observations of resistance to salt injury and overall plant vigor and stood out with the greatest growth each year and cumulatively throughout the study. ‘Elliott’ had the highest K:Na ratio in 2019, shared the highest K:Na ratio in 2020 with ‘VC1-68’, was among the seedlings with the lowest leaf sodium concentrations during both years, and had the second lowest mortality of all the seedlings chosen. Another issue that pecan growers face is tree to tree variability that is reflected in nutrient acquisition within an orchard. It is important to have knowledge of variability so that each tree receives adequate nutrition. The orchard block mean leaf nutrient concentration should be high enough that all individual trees receive adequate nutrition. Practical leaf sampling of orchards requires sampling only a small portion of the trees randomly, and provides a mean value from which it is difficult to determine minimum (or maximum) nutrient concentrations extent in the sampled orchard block. To address this issue, a two-year experiment was conducted in an orchard in San Simon, AZ. The experimental plot consisted of ‘Wichita’ pecan pollinated with ‘Western’ (every fourth row). Soil and leaf samples were collected each year. Trunk measurements were made in the dormant seasons. Photosynthesis measurements of the ‘Wichita’ trees were made in 2019. The data were analyzed to determine magnitude and patterns of variability. Nutrient uptake varied between the cultivars. A lower mean and more variability in leaf zinc concentrations was found among the ‘Wichita’ trees than ‘Western’ during both years. We concluded that due to lack of variability sources within the orchard block, as well as finding little difference in row to row average mean leaf zinc concentrations, or in average mean leaf zinc concentrations of tree position within rows in either year, that position in the field was not the primary source of variability in leaf zinc concentration. From our 2019 data set we determined that a mean leaf zinc concentration of approximately 25 mg·kg-1 was needed to ensure that no more than 5% of the trees would fall below a target mean leaf zinc concentration (determined from previous research) of 15 mg·kg-1. This concentration is significantly lower than many published recommendations. Further, using the leaf nutrient with the highest coefficient of variance (zinc) for 2019 we determined a range of sample sizes and their associated relative margins of error from the true population mean. A sample size of 35 trees with a relative margin of error of 10% from the true population mean at 95% confidence is recommended for practical sampling purposes.
    • Syntactic and Morphological Complexity Measures As Markers of L2 Development in Russian

      Staples, Shelley L.; Novikov, Aleksey; Leafgren, John; Fernández, Julieta (The University of Arizona., 2021)
      Within second language acquisition research, L2 development has been traditionally analyzed through the dimensions of Complexity, Accuracy and Fluency (CAF) (Larsen-Freeman, 2009; Ortega, 2003; Skehan, 2009). Complexity within the CAF framework has gained the most attention and has often been examined through measures associated with clausal length (Bulté & Housen, 2012). In contrast, the present study examines complexity through the register-functional framework (Biber, Gray & Poonpon, 2011; Biber, Gray & Staples, 2016). The fundamental principle of the register-functional framework is that complexity is situation-dependent, meaning that complexity depends on the situational characteristics of texts such as communicative purposes of texts and their production circumstances. Thus, instead of relying on particular measures of complexity such as complexity indices or T-unit measures, the investigation of complexity within the register-functional framework begins with a linguistic description of texts. The present study builds on the foundation of the register-functional framework and adds to the body of L2 development research by being the first of its kind in L2 Russian. Previous studies that investigated L2 complexity in Russian are rather few (e.g., Henry, 1996; Kisselev & Alsufieva, 2017) but are also limited in that they 1) only study writing; 2) use either omnibus complexity measures or a rather limited set of measures; 3) investigate high levels of proficiency. The overall goal of this study is to provide a comprehensive description of syntactic and morphological L2 development at lower levels (e.g., beginner to intermediate) across speech and writing in Russian. To address these research gaps, the present study examines L2 development through morphological and syntactic complexity measures in L2 Russian. The study uses a corpus of written and spoken texts produced by learners across four program levels (i.e. the first two years of Russian). First, the study examines individual measures of morphological and syntactic complexity and interprets the findings in light of the curriculum progression and assignment effects. Second, the study performs a Multidimensional Analysis (MD) in order to group the individual measures of complexity into dimensions of complexity that are interpreted functionally. The results of the study show that both syntactic and morphological complexity measures behave differently across program levels. For example, while adverbial if- and when- clauses increase with program level, adverbial because-clauses decline. Similarly, while post-modifying nouns increase, attributive adjectives decrease. In terms of morphological complexity, the measures that have clear increasing trends across program levels are genitive nouns and adjectives, instrumental nouns and adjectives, dative nouns, and past perfective and imperfective verbs. The Multidimensional Analysis (MD) yielded two dimensions of complexity: 1) Narrative vs. Non-narrative/Descriptive, and 2) Informational vs. Personal. The narrative side of Dimension 1 includes perfective and imperfective past verbs, while the non-narrarive side includes 3rd person plural verbs and attributive adjectives. The informational side of Dimension 2 is represented by complexity measures such as prepositional adjectives, genitive singular nouns, genitive adjectives and attributive adjectives. In contrast, the personal side is characterized by such measures as 1st person present tense verbs, accusative nouns and non-finite complement clauses. These dimensions of complexity showed significant differences between program levels. Significant interactions between program level and mode were also demonstrated pointing out to differences between speech and writing with regards to these dimensions across program levels. Although the complexity measures included in these dimensions are very specific to Russian, these two dimensions have been consistently identified in other MD studies.
    • Prompting Students to Write: Designing and Using Second Language Writing Assignment Prompts

      Tardy, Christine; Palese, Emily Anne; Staples, Shelley; Gilmore, Perry; Castek, Jill (The University of Arizona., 2021)
      In university-level composition courses, assignment prompts are fundamental in shaping students’ understanding of major writing projects. Aiming to be instructive and descriptive while also clear and concise, instructors use a series of moves (Swales, 1990) and modals in writing assignment prompts to express requirements, suggestions, and expectations (Biber, 2006b). Striving to balance nuance and clarity, though, composition instructors often find that “creating explicit, nonambiguous prompts for writing tasks...can be a daunting task” (Crusan, 2010, p. 68). This “daunting” task is even greater for instructors who are new to teaching composition and for instructors of students who use English as an additional language (EAL) (Brand, 1992; Caplan, 2019; Kroll & Reid, 1994; Reid & Kroll, 1995; Restaino, 2012).To better understand how instructors signal requirements, suggestions, and expectations in writing prompts, this study uses a corpus of second language (L2) writing prompts to identify conventional moves, modal frequencies, and the relationship between moves and modals. Analysis of these data highlights conventional patterns of modals in moves, as well as examples of inconsistent modal-move pairings. These data are complemented by an investigation into how instructors design and use their prompts, as well as how EAL students use and value those prompts. Findings from this research identify ways in which design choices, prompt uses, and student values align. A greater understanding of prompt conventions, uses, and student values can be used to foster heightened meta-awareness and build genre-specific knowledge (Tardy, 2009) of this important pedagogical genre for instructors and students alike (Hyland, 2007). Instructors can use these findings to review their prompts to determine whether their moves and modal choices are intentional and effective. Instructors can also use these data to guide students to more precisely interpret assignment prompts. Finally, teacher educators can use these conclusions to model how to design clear, effective assignment prompts.
    • Disciplinary Routes: Negotiating Academic Identity in Graduate-Level Writing

      Tardy, Christine; Gevers, Jeroen; Atkinson, Dwight; Warner, Chantelle; Perez-Llantada, Carmen (The University of Arizona., 2021)
      Over the past half century, writing scholars and applied linguists have examined students’ socialization into the discourses and practices of academia, highlighting the importance of writing in this regard. Specifically, scholars have considered how students try to reconcile their interests and their evolving identities with classroom and disciplinary writing expectations (Casanave, 2002), a process that is mediated by institutional or program requirements, interactions with instructors and classmates, course artifacts, and internalized notions of what it means to be a successful student or academic (Prior, 1998; see also Anderson, 2017). This work has increasingly recognized writing as a socially embedded activity and highlighted students’ own perspectives on their learning. However, two distinct aspects of graduate-level writing have remained underexplored: (1) writing in interdisciplinary programs, which require students to become fluent in multiple research traditions, and (2) the role of classroom-based writing, including newer genres and low-stakes tasks, in advancing students’ learning and self-perceptions. I respond to these gaps by sharing an ethnographically-oriented (Paltridge, Starfield, & Tardy, 2016) study of nine multilingual doctoral students in interdisciplinary programs at “Southwestern University,” a large public research university in the U.S. Southwest. At the time of the study, the participants were in the process of completing their coursework, for which they produced a range of writing assignments, including discussion posts, reading responses, ethnographic descriptions, multimodal presentations, literature reviews, and research proposals. Using class observations, literacy and talk-around-text interviews (Lillis, 2008), and textual analysis, I examine how the students presented themselves in their writing over a period of two semesters, focusing on their disciplinary affinities and research interests. This way, I aim to capture graduate-level writing as a “lived-through experience” (Chiseri-Strater, 1991, p. xxi) that is shaped by “a complex array of social, personal, historical, cultural, and linguistic factors” (Casanave, 2002, p. 146). My analysis draws on theories of genre, (inter)disciplinarity, multilingualism, and writer identity or voice. The findings of this study suggest that classroom-based writing plays a more important part in “disciplinary becoming” (Curry, 2016; Dressen-Hammouda, 2008) than is often assumed, as it provides students with opportunities to adopt various subject positions and thus negotiate their sense of self as aspiring scholars or professionals. In addition, I show how digital and multimodal genres structure the learning process by facilitating various forms of peer socialization which doctoral students orient to their classmates as mutual apprentices. My analysis further indicates that classroom-based writing may help students find their way in unfamiliar disciplines and research traditions and help them formulate identities as interdisciplinary scholars. Apart from giving nuanced insight into the connections between writer identity, genre knowledge, and disciplinary learning, I offer suggestions for practitioners to improve writing instruction and support.
    • Exploring Interculturality in the Colombian EFL Classroom: A Situated Collaborative Case Study

      Dupuy, Beatrice; Sagre, Anamaria; Warner, Chantelle; Short, Kathy; Atkinson, Dwight (The University of Arizona., 2021)
      An intercultural perspective on language learning and teaching has become prominent over the past three decades. As a result, diverse theoretical frameworks, methods, and approaches have been developed to understand and explore interculturality in foreign and second language classrooms (e.g., Byram, 1997; Byrnes, 2002, 2008; Dervin, 2009, 2011; Kramsch, 1998, 2011; Liddicoat, 2004; Risager, 2007). As a goal of foreign language instruction, interculturality has spurred significant research in second and foreign language education. For example, extensive scholarship has explored how telecollaboration projects and experiences abroad can enhance students’ development of interculturality (e.g., Alred et al., 2003; Basharina, 2007; Byram et al., 2001; Blyth, 2011; Chen, 2017). Another line of research has delved into teachers’ and students’ different conceptualizations and understandings of interculturality (e.g., Castro et al., 2004; Collings, 2007; Moore, 2006; Ortaçtepe, 2015; Sercu, 2006; Young & Sachdev, 2011). From a pedagogical perspective, research has explored the procedures, methodologies, and core practices that pre-service and in-service teachers use to foster interculturality in high school and college foreign language curricula as well as the challenges teachers face when aiming to do so (e.g., Byram & Kramsch, 2008; Díaz, 2013a; Ghanem, 2017; Kramsch, 2011; Kearney, 2015, 2021; Kohler, 2015).Even though the existing research has shed light on the development of interculturality and the beliefs both learners and teachers hold about this concept, research about how teachers teach for interculturality in public high school classrooms and the contradictions that emerge in this process remains limited. Diverse scholars (Díaz, 2013a; Kramsch, 2011, 2013; Kearney, 2015, 2021; Kohler, 2015; Liddicoat, 2011) have argued that there is a need to delve more deeply into the practices teachers use to teach for interculturality in their classrooms and the limitations that might prevent them from doing so. Grounded in situated collaborative qualitative research (Atkinson, 2005; Erickson 1986, 2018) and formative intervention research founded upon the principles of third-generation Activity Theory (Engeström, 1987; Engeström & Sannino, 2010), the present study aims at exploring the understanding that four experienced EFL teachers in three public schools in Córdoba, Colombia have of interculturality; the ways in which they teach it in their classrooms; and the contradictions that emerge in doing so. Data were collected over the course of nine months and included individual interviews, focus group meetings, class observations, stimulated recall interviews, and artifacts. The findings reveal that the formative intervention facilitated the incorporation of new tools (e.g., multimodal texts, the combination of L1 and L2), roles (e.g., teachers as researchers), and community (e.g., parents as part of L2 learning) that propelled the integration of interculturality in the L2 classroom. The findings also underscore the role of collaborative research in the design and implementation of intercultural practices that include: 1) exploring the known before moving to the unknown; 2) exploring practices and products more deeply; 3) moving from factual information to perspectives; 4) challenging existing sources; and 5) contextualizing existing practices that respond to teachers’ contextual needs while aligning with national regulations. The study also shows how contradictions were explored, analyzed, and dealt with collaboratively.
    • Sleep on It: Sleep and Executive Function in Pediatric Type 1 Diabetes Mellitus

      Perfect, Michelle; Bluez, Grai Peace; Yoon, Jina; Vega, Desiree (The University of Arizona., 2021)
      Type 1 diabetes mellitus (T1DM) is an increasingly prevalent pediatric chronic illness characterized by devastating metabolic dysfunction for which there is no cure. Attaining independent mastery in disease management is critical for developing youth with increasing social independence. Previous research has linked sleep to glycemic regulation and T1DM management behaviors. The purpose of this study was to examine the impact of fragmented sleep (actigraphy fragmentation index [Acti SFI] and polysomnography N1%) on visual, verbal, and behavior measures of executive function that may have implications for disease management in a sample of youth with T1DM. Multiple regression analysis found that Acti SFI and N1% significantly predicted visual and behavioral executive functioning; though, there was an unexpected differential effect of N1% compared to Acti SFI. Examining glycemic regulation as a moderator, via continuous glucose monitoring (CGM), revealed that glycemic control (CGM %Target) significantly moderated the effect of N1% on visual executive functioning, indicating that poor glycemic control may create relative cognitive vulnerability to sleep fragmentation. There was an unexpected finding that in youth with the best glycemic control, increased Acti SFI was associated with higher scores on a measure of verbal fluency. This study is the first to examine differential utility in measures of sleep fragmentation associated with executive functioning in youth with T1DM. Given notable glycemic dysregulation in the present study sample, results highlight a need to better understand how sleep impacts developing executive functioning skills in this population, with a focus on supporting executive functioning skills related to diabetes management behaviors. Continued future research exploring an actigraphy sleep fragmentation index, physically restless sleep, and their relationship to diabetes management behaviors is also recommended.