Now showing items 21-40 of 75896

    • Simplified method to quantify valve back-leak uncovers severe mesenteric lymphatic valve dysfunction in mice deficient in connexins 43 and 37

      Castorena-Gonzalez, Jorge A; Srinivasan, R Sathish; King, Philip D; Simon, Alexander M; Davis, Michael J; Univ Arizona, Dept Physiol (WILEY, 2020-04-08)
      Lymphatic valve defects are one of the major causes of lymph transport dysfunction; however, there are no accessible methods for quantitatively assessing valve function. This report describes a novel technique for quantifying lymphatic valve back-leak. Postnatal endothelial-specific deletion of connexin 43 (Cx43) in connexin 37 null (Cx37-/- ) mice results in rapid regression of valve leaflets and severe valve dysfunction. This method can also be used for assessing the function of venous and lymphatic valves from various species, including humans.
    • Breadwinner Seeks Bottle Warmer: How Women’s Future Aspirations and Expectations Predict Their Current Mate Preferences

      Croft, Alyssa; Schmader, Toni; Beall, Alec; Schaller, Mark; Univ Arizona, Dept Psychol (SPRINGER/PLENUM PUBLISHERS, 2020-06)
      Contemporary women in Western cultures are often trying to juggle careers alongside personal and societal expectations for childrearing in an effort to "have it all." We examine the effects of this balancing act on heterosexual women's mate selection motivations. Across three Canadian samples (n = 360), we tested concurrent hypotheses about the desirability of both similar and complementary characteristics in a potential mate. Specifically, women's aspirations (to prioritize career over family) and their expectations for the roles they will most likely adopt within their future partnerships (primary breadwinner and/or caregiver) were tested as key predictors of mate preferences. Although specific effects varied across samples, a mega-analysis of the combined sample and an internal meta-analysis of effect sizes from the three studies provided support for both complementary and similarity motives (controlling for gender role attitudes). Women's aspirations to prioritize career (over family) predicted greater similarity in mate preferences, such that they placed less importance on men's parenting qualities, more importance on their access to financial resources, and preferred a career-oriented over family-oriented exemplar. However, women's expectations of actually taking on the breadwinner role predicted greater complementarity in mate preferences (greater desirability of parenting qualities and a family-oriented partner; with financial resources rated as less important). Our work expands current understanding of women's decision-making processes when selecting a mate and has implications for men's changing traits and roles.
    • Age influences domestic dog cognitive performance independent of average breed lifespan

      Watowich, Marina M; MacLean, Evan L; Hare, Brian; Call, Josep; Kaminski, Juliane; Miklósi, Ádám; Snyder-Mackler, Noah; Univ Arizona, Sch Anthropol; Univ Arizona, Dept Psychol; Univ Arizona, Cognit Sci (SPRINGER HEIDELBERG, 2020-04-30)
      Across mammals, increased body size is positively associated with lifespan. However, within species, this relationship is inverted. This is well illustrated in dogs (Canis familiaris), where larger dogs exhibit accelerated life trajectories: growing faster and dying younger than smaller dogs. Similarly, some age-associated traits (e.g., growth rate and physiological pace of aging) exhibit accelerated trajectories in larger breeds. Yet, it is unknown whether cognitive performance also demonstrates an accelerated life course trajectory in larger dogs. Here, we measured cognitive development and aging in a cross-sectional study of over 4000 dogs from 66 breeds using nine memory and decision-making tasks performed by citizen scientists as part of the Dognition project. Specifically, we tested whether cognitive traits follow a compressed (accelerated) trajectory in larger dogs, or the same trajectory for all breeds, which would result in limited cognitive decline in larger breeds. We found that all breeds, regardless of size or lifespan, tended to follow the same quadratic trajectory of cognitive aging-with a period of cognitive development in early life and decline in later life. Taken together, our results suggest that cognitive performance follows similar age-related trajectories across dog breeds, despite remarkable variation in developmental rates and lifespan.
    • Handheld UV fluorescence spectrophotometer device for the classification and analysis of petroleum oil samples

      Bills, Matthew V; Loh, Andrew; Sosnowski, Katelyn; Nguyen, Brandon T; Ha, Sung Yong; Yim, Un Hyuk; Yoon, Jeong-Yeol; Univ Arizona, Dept Biomed Engn (ELSEVIER ADVANCED TECHNOLOGY, 2020-07-01)
      Oil spills can be environmentally devastating and result in unintended economic and social consequences. An important element of the concerted effort to respond to spills includes the ability to rapidly classify and characterize oil spill samples, preferably on-site. An easy-to-use, handheld sensor is developed and demonstrated in this work, capable of classifying oil spills rapidly on-site. Our device uses the computational power and affordability of a Raspberry Pi microcontroller and a Pi camera, coupled with three ultraviolet light emitting diodes (UV-LEDs), a diffraction grating, and collimation slit, in order to collect a large data set of UV fluorescence fingerprints from various oil samples. Based on a 160-sample (in 5x replicates each with slightly varied dilutions) database this platform is able to classify oil samples into four broad categories: crude oil, heavy fuel oil, light fuel oil, and lubricating oil. The device uses principal component analysis (PCA) to reduce spectral dimensionality (1203 features) and support vector machine (SVM) for classification with 95% accuracy. The device is also able to predict some physiochemical properties, specifically saturate, aromatic, resin, and asphaltene percentages (SARA) based off linear relationships between different principal components (PCs) and the percentages of these residues. Sample preparation for our device is also straightforward and appropriate for field deployment, requiring little more than a Pasteur pipette and not being affected by dilution factors. These properties make our device a valuable field-deployable tool for oil sample analysis.
    • Associations of air pollution with obesity and body fat percentage, and modification by polygenic risk score for BMI in the UK Biobank

      Furlong, Melissa A; Klimentidis, Yann C; Univ Arizona, Mel & Enid Zuckerman Coll Publ Hlth, Dept Commun Environm & Policy, Div Environm Hlth Sci; Univ Arizona, Mel & Enid Zuckerman Coll Publ Hlth, Dept Epidemiol & Biostat (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2020-06)
      Air pollution has consistently been associated with cardiometabolic outcomes, although associations with obesity have only been recently reported. Studies of air pollution and adiposity have mostly relied on body mass index (BMI) rather than body fat percentage (BF%), and most have not accounted for noise as a possible confounder. Additionally, it is unknown whether genetic predisposition for obesity increases susceptibility to the obesogenic effects of air pollution. To help fill these gaps, we used the UK Biobank, a large, prospective cohort study in the United Kingdom, to explore the relationship between air pollution and adiposity, and modification by a polygenic risk score for BMI. We used 2010 annual averages of air pollution estimates from land use regression (NO2, NOX, PM2.5, PM2.5absorbance, PM2.5-10, PM10), traffic intensity (TI), inverse distance to road (IDTR), along with examiner-measured BMI, waist-hip-ratio (WHR), and impedance measures of BF%, which were collected at enrollment (2006-2010, n = 473,026) and at follow-up (2012-2013, n = 19,518). We estimated associations of air pollution with BMI, WHR, and BF% at enrollment and follow-up, and with obesity, abdominal obesity, and BF%-obesity at enrollment and follow-up. We used linear and logistic regression and controlled for noise and other covariates. We also assessed interactions of air pollution with a polygenic risk score for BMI. On average, participants at enrollment were 56 years of age, 54% were female, and 32% had completed college or a higher degree. Almost all participants (~95%) were white. All air pollution measures except IDTR were positively associated with at least one continuous measure of adiposity at enrollment. However, NO2 was negatively associated with BMI but positively associated with WHR at enrollment, and IDTR was also negatively associated with BMI. At follow-up (controlling for enrollment adiposity), we observed positive associations for PM2.5-10 with BMI, PM10 with BF%, and TI with BF% and BMI. Associations were similar for binary measures of adiposity, with minor differences for some pollutants. Associations of NOX, NO2, PM2.5absorbance, PM2.5 and PM10, with BMI at enrollment, but not at follow-up, were stronger among individuals with higher BMI polygenic risk scores (interaction p <0.05). In this large, prospective cohort, air pollution was associated with several measures of adiposity at enrollment and follow-up, and associations with adiposity at enrollment were modified by a polygenic risk score for obesity.
    • Fire impacts on a forest obligate: western gray squirrel response to burn severity

      Mazzamuto, Maria Vittoria; Mazzella, Maxwell N.; Merrick, Melissa J.; Koprowski, John L.; Univ Arizona, Sch Nat Resources & Environm, Environm & Nat Resources 2 (SPRINGER HEIDELBERG, 2020-06)
      In the southwestern United States, climate change and climate-fire dynamics are affecting the distribution of natural and managed ecosystems. Forest obligate species on sky islands can experience a restriction in range with the increase of destructive forest fires. Using presence/absence data collected by hair tubes, we identified key habitat features that determine the western gray squirrel (Sciurus griseus) distribution on the sky island of the San Bernardino Mountains (California, USA) and determined post-fire differential use of burn severity in a landscape modified by fire. Gray squirrel presence was related to habitat features important for this species' ecology and behavior, especially those associated with mature forests. The species was detected in areas with a high percentage of conifers that provide both an important food resource and good branches and cavities for nest sites. Gray squirrels occurred in all burn severities but occurred more in low and high severity sites than unburned sites. These results suggest that the gray squirrel can persist after a wildfire and can take advantage of the post-fire habitat structure if a mosaic of burn severities is maintained in the forest.
    • Constructive and destructive interparental conflict, parenting, and coparenting alliance

      Kopystynska, Olena; Barnett, Melissa A; Curran, Melissa A; Univ Arizona, Dept Family Studies & Human Dev (AMER PSYCHOLOGICAL ASSOC, 2020-06)
      Guided by the spillover hypothesis of family systems theory, we used data from the Building Strong Families project to examine intrafamily relations between destructive and constructive interparental conflict, harsh and supportive parenting behaviors, and coparenting alliance across different family configurations: married, cohabiting, and noncohabiting (never married) parents. Our sample (N = 2,784 couples/parents) was racially diverse, low-income couples/parents who were unmarried at the conception of their child. All variables were measured when children were approximately 36 months of age. Interparental conflict was assessed through an instrument that included both parents' reported conflict in the relationship and the perception of the other parent's conflict behaviors. Parenting behaviors were measured through observational data and coparenting alliance was based on mothers' and fathers' reports. As expected, path analyses revealed that destructive interparental conflict was related to lower levels of coparenting alliance, whereas constructive interparental conflict was related to higher levels of coparenting alliance, for mothers and fathers. For fathers only, destructive interparental conflict related to harsh parenting, suggesting that paternal parenting is vulnerable to the quality of the relationship with the mother. None of the proposed associations differed by family structure. These findings suggest the need for intervention programs to focus on promoting adaptive conflict management behaviors rather than on family structure. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
    • Mediation and boundary marking: A case study of making literacies across a makerspace

      Shivers-McNair, Ann; Univ Arizona (Elsevier BV, 2020-03)
      This paper draws on data from a year-long participatory ethnographic case study of a makerspace to argue for and articulate a methodology to account for dynamic boundary marking practices: what counts as "making," what counts as "literacy," who counts as "maker," who counts as "literate." Specifically, the author argues that in order to understand making and maker literacies, we have to understand boundary marks, because how we mark boundaries shapes what and who come to matter (both in a material and in a semiotic sense), which in turn shapes what and who get made, by whom, and for whom. Key to this methodology is a refiguring of mediation that draws on feminist and decolonial approaches to knowledge making and communication that emphasize the ongoing marking of boundaries of media, literacies, and bodies. To illustrate this methodology, the author traces becomings, un-becomings, and re-becomings of makers, literacies, tools, and relations across a makerspace. The author concludes by offering implications for further developing and adapting the methodology.
    • General equilibrium rebound from energy efficiency innovation

      Lemoine, Derek; Univ Arizona, McClelland Hall (ELSEVIER, 2020-06)
      Energy efficiency improvements "rebound" when economic responses undercut their direct energy savings. I show that general equilibrium channels typically amplify rebound by making consumption goods cheaper but typically dampen rebound by increasing demand for non-energy inputs to production and by changing the size of the energy supply sector. Improvements in the efficiency of the energy supply sector generate especially large rebound because they make energy cheaper in all other sectors. Quantitatively, general equilibrium channels reduce rebound in U.S. consumption good sectors from 39% to 28% but increase rebound in the energy supply sector from 42% to 80%. (C) 2020 Elsevier B.V. All rights reserved.
    • Rural Telehealth Team Education for Baccalaureate and Nurse Practitioner Students

      Knight, Elizabeth P; Prettyman, Allen V; Univ Arizona, Coll Nursing (SLACK INC, 2020-05)
      Background: Rural areas face health care workforce shortages. Nursing students seeking rural employment require instruction and clinical experience in using telehealth to work in health care teams. Method: An innovative telehealth consultation simulation paired nurse practitioner (NP) students with prelicensure baccalaureate nursing degree (BSN) students. The simulation aimed to enhance NP student proficiency and confidence in telehealth consultation skills and to foster professional role development through exposure to telehealth nursing roles for RNs and NPs. On-campus BSN students assumed the role of the RN in a rural clinic and consulted with off-campus NP students using telehealth technology in the care of a standardized patient. Results: Participants demonstrated level-appropriate proficiency and reported confidence in telehealth consultation and favorable attitudes toward intraprofessional communication. Conclusion: An intraprofessional educational model allowing BSN and NP students to develop telehealth consultation skills successfully addressed a gap in preparing nursing students to meet rural health care workforce needs.
    • Navigating the ‘retail apocalypse’: A framework of consumer evaluations of the new retail landscape

      Helm, Sabrina; Kim, Soo Hyun; Van Riper, Silvia; Univ Arizona, Retailing & Consumer Sci (ELSEVIER SCI LTD, 2020-05)
      Strong signals exist for a permanent restructuring of retailing, where traditional physical retailers may not fully recover. Such transformation will have vast implications for consumers, the industry, and society in general. This study explores U.S. consumers' evaluations of these profound changes sometimes referred to as the 'retail apocalypse.' Two studies, a content analysis of reader comments in response to articles featuring reports on large-scale store closures, and structured online consumer interviews, provide insights into consumers' perspectives. We include consumer-derived explanations for the decline in physical retail, and the growth of online shopping, as well as anticipated consequences for both, individual consumers and society in general, in a conceptual framework. We find many consumers lamenting the disappearance of physical retailers. Most expect negative consequences for themselves and society. However, many consumers also describe physical retailers as often unable to deliver on basic retail functions, and many are accepting of a future with very few physical stores. Based on these findings, we develop practical implications for the retail industry and public policy, as well as future research opportunities.
    • Physical activity, sedentary time, and longitudinal bone strength in adolescent girls

      Bland, V L; Bea, J W; Roe, D J; Lee, V R; Blew, R M; Going, S B; Univ Arizona, Dept Nutr Sci; Univ Arizona, Dept Med; Univ Arizona, Canc Ctr; Univ Arizona, Dept Epidemiol & Biostat (SPRINGER LONDON LTD, 2020-05-09)
      The association between baseline physical activity and sedentary time with 2-year longitudinal bone strength was evaluated. The effect of physical activity on bone depended on maturity status. Sedentary time did not negatively impact bone outcomes, regardless of maturity. Maturity should be considered when developing exercise interventions to improve bone outcomes. Introduction Physical activity during adolescence is important to obtain peak bone mass; however, adolescents are increasingly sedentary, potentially increasing risk for osteoporosis later in life. The aim of this study was to assess the association of physical activity and sedentary time with 2-year longitudinal bone outcomes in adolescent females (69% Hispanic/31% non-Hispanic). Methods Bone strength was assessed at the 66% tibia, 20% femur, and 66% radius of 9- to 12-year-old girls (n = 131) using peripheral quantitative computed tomography at baseline and 2-year follow-up. Physical activity and sedentary time were assessed via accelerometry. Linear regression analyses were used to assess whether baseline vigorous physical activity (VPA), moderate physical activity (MPA), light physical activity (LPA), or sedentary time predict longitudinal bone outcomes, adjusting for relevant confounders. Results Significant interactions were found between maturity offset and physical activity. In weight-bearing bones, significant interactions were primarily identified between VPA and maturity offset. Interactions indicated that VPA was associated with favorable bone outcomes at the tibia and femur in girls further past the age of PHV. However, this favorable effect was not observed in girls closer to the age of PHV. At the radius, interactions were primarily observed between LPA and maturity offset. Again, LPA was more beneficial for girls further past the age of PHV. Sedentary time did not significantly influence bone outcomes. Conclusion The effects of physical activity on bone may be dependent on maturity. Therefore, physical activity interventions, with attention to maturity status, may be required to optimize bone strength in girls.
    • Feeling alone in your subjectivity: Introducing the State Trait Existential Isolation Model (STEIM)

      Helm, Peter J.; Greenberg, Jeff; Park, Young Chin; Pinel, Elizabeth C.; Univ Arizona, Dept Psychol (WILEY, 2019-07)
      Psychologists have devoted substantial attention to social isolation and to loneliness but only recently have psychologists begun to consider existential isolation. Existential isolation is a unique form of interpersonal isolation, related to, but distinct from loneliness and social isolation. Feeling existentially isolated is the subjective sense one is alone in one's experience, and that others cannot understand one's perspective. In the current paper, we propose a conceptual model of existential isolation and review relevant evidence. The model proposes that the experience of existential isolation can be situational, context dependent, or a trait-like pervasive sense that others do not validate one's subjective experience. The model posits acute and chronic causes of existential isolation and consequences of the state and trait forms of it. Reactions to state existential isolation produce momentary and short-term effects whereby an individual's sense of validation of their worldview is threatened and attempts are made to eliminate this feeling. In contrast, trait existential isolation leads to reduced identification with cultural sources of meaning and withdrawal from seeking rewarding relationships, which leads to more long-term consequences such as chronic need depletion and deficits in well-being. We briefly discuss potential moderators that may affect whether and when individuals experience existential isolation and possible strategies for reducing existential isolation, and recommend directions for future research.
    • Prescriptions for Correcting Ultraviolet-based Redshifts for Luminous Quasars at High Redshift

      Dix, Cooper; Shemmer, Ohad; Brotherton, Michael S.; Green, Richard F.; Mason, Michelle; Myers, Adam D.; Univ Arizona, Dept Astron (IOP PUBLISHING LTD, 2020-04-08)
      High-redshift quasars typically have their redshift determined from rest-frame ultraviolet (UV) emission lines. However, these lines, and more specifically the prominent C iv lambda 1549 emission line, are typically blueshifted yielding highly uncertain redshift estimates compared to redshifts determined from rest-frame optical emission lines. We present near-infrared spectroscopy of 18 luminous quasars at 2.15 z < 3.70 that allows us to obtain reliable systemic redshifts for these sources. Together with near-infrared spectroscopy of an archival sample of 44 quasars with comparable luminosities and redshifts, we provide prescriptions for correcting UV-based redshifts. Our prescriptions reduce velocity offsets with respect to the systemic redshifts by similar to 140 km s(-1) and reduce the uncertainty on the UV-based redshift by similar to 25% with respect to the best method currently used for determining such values. We also find that the redshifts determined from the Sloan Digital Sky Survey Pipeline for our sources suffer from significant uncertainties, which cannot be easily mitigated. We discuss the potential of our prescriptions to improve UV-based redshift corrections given a much larger sample of high-redshift quasars with near-infrared spectra.
    • SYMBA: An end-to-end VLBI synthetic data generation pipeline

      Roelofs, F.; Janssen, M.; Natarajan, I.; Deane, R.; Davelaar, J.; Olivares, H.; Porth, O.; Paine, S. N.; Bouman, K. L.; Tilanus, R. P. J.; et al. (EDP SCIENCES S A, 2020-04-03)
      Context. Realistic synthetic observations of theoretical source models are essential for our understanding of real observational data. In using synthetic data, one can verify the extent to which source parameters can be recovered and evaluate how various data corruption effects can be calibrated. These studies are the most important when proposing observations of new sources, in the characterization of the capabilities of new or upgraded instruments, and when verifying model-based theoretical predictions in a direct comparison with observational data. Aims. We present the SYnthetic Measurement creator for long Baseline Arrays (SYMBA), a novel synthetic data generation pipeline for Very Long Baseline Interferometry (VLBI) observations. SYMBA takes into account several realistic atmospheric, instrumental, and calibration effects. Methods. We used SYMBA to create synthetic observations for the Event Horizon Telescope (EHT), a millimetre VLBI array, which has recently captured the first image of a black hole shadow. After testing SYMBA with simple source and corruption models, we study the importance of including all corruption and calibration effects, compared to the addition of thermal noise only. Using synthetic data based on two example general relativistic magnetohydrodynamics (GRMHD) model images of M 87, we performed case studies to assess the image quality that can be obtained with the current and future EHT array for different weather conditions. Results. Our synthetic observations show that the effects of atmospheric and instrumental corruptions on the measured visibilities are significant. Despite these effects, we demonstrate how the overall structure of our GRMHD source models can be recovered robustly with the EHT2017 array after performing calibration steps, which include fringe fitting, a priori amplitude and network calibration, and self-calibration. With the planned addition of new stations to the EHT array in the coming years, images could be reconstructed with higher angular resolution and dynamic range. In our case study, these improvements allowed for a distinction between a thermal and a non-thermal GRMHD model based on salient features in reconstructed images.
    • A Deliberate Bit Flipping Coding Scheme for Data-Dependent Two-Dimensional Channels

      Bahrami, Mohsen; Vasic, Bane; Univ Arizona, Dept Elect & Comp Engn (Institute of Electrical and Electronics Engineers (IEEE), 2020-02)
      In this paper, we present a deliberate bit flipping (DBF) coding scheme for binary two-dimensional (2-D) channels, where specific patterns in channel inputs are the significant cause of errors. The idea is to eliminate a constrained encoder and, instead, embed a constraint into an error correction codeword that is arranged into a 2-D array by deliberately flipping the bits that violate the constraint. The DBF method relies on the error correction capability of the code being used so that it should be able to correct both deliberate errors and channel errors. Therefore, it is crucial to flip minimum number of bits in order not to overburden the error correction decoder. We devise a constrained combinatorial formulation for minimizing the number of flipped bits for a given set of harmful patterns. The generalized belief propagation algorithm is used to find an approximate solution for the problem. We evaluate the performance gain of our proposed approach on a data-dependent 2-D channel, where 2-D isolated-bits patterns are the harmful patterns for the channel. Furthermore, the performance of the DBF method is compared with classical 2-D constrained coding schemes for the 2-D no isolated-bits constraint on a memoryless binary symmetric channel.
    • An open, scalable, and flexible framework for automated aerial measurement of field experiments

      Schnaufer, Christophe; Pistorius, Julian L.; LeBauer, David S.; Univ Arizona (SPIE, 2020-05-19)
      Unoccupied areal vehicles (UAVs or drones) are increasingly used in field research. Drones capable of routinely and consistently capturing high quality imagery of experimental fields have become relatively inexpensive. However, converting these images into scientifically useable data has become a bottleneck. A number of tools exist to support this work ow, but there is no framework for making these tools interopreable, sharable, and scalable. Here we present an initial draft of the Drone Processing Pipeline (DPP), a framework for processing agricultural research imagery that supports best practices and interoperability. DPP emphasizes open software and data that can be shared among and used in whole or part by the research community. We are building the DPP as a distributed, scalable, and flexible pipeline for converting drone imagery into orthomosaics, point clouds, and plot level statistics. Our intent is not to replace, but to integrate components from the emerging ecosystem of utilities with a focus on end-to-end automation and scalability. The initial focus of DPP is the measurements of experimental plots in field research. In the future we expect that standardization will enable new scientific discovery by facilitating collaboration and sharing of software and data. Our vision is to create a processing pipeline that is open, flexible, extensible, portable, and automated. With modern tools, deploying a pipeline on a laptop or HPC should only take a single command. Running a pipeline and publishing data should require only input data and a defined work flow.
    • Coyote Papers 22: Frontmatter and TOC

      Nitschke, Remo; Romero Diaz, Damian Y; Powell, John; De la Cruz Sánchez, Gabriela (University of Arizona Linguistics Circle, 2020)
    • Escaping siloed phonology: Framing Irish lenition in Emergent Grammar

      McCullough, Kerry; University of Arizona (University of Arizona Linguistics Circle, 2020)
      Irish displays a complex mutation system in which regular phonological alternations are sensitive to arbitrary morphological information. The Emergent Grammar (EG) model is well-suited to address this phenomenon. This paper details how the model's technology accounts for the phonological regularity and morphological opacity of lenition in Irish.
    • Resistance, Consciousness, and Filipina Hip Hop Identity: A Phonological Analysis

      Tseng, Serene; University of Arizona (University of Arizona Linguistics Circle, 2020)
      In this paper, I investigate the phonology and Hip Hop Language of two Filipina American rappers, Ruby Ibarra and Rocky Rivera, and how they express their understandings of identity and language and race, all in the context of Hip Hop and Asian America.