How particle shape affects granular segregation in industrial and geophysical flows.

Industrial and environmental granular flows commonly exhibit a phenomenon known as "granular segregation," in which grains separate according to physical characteristics (size, shape, density), interfering with industrial applications (cement mixing, medicine, and food production) and fundamentally altering the behavior of geophysical flows (landslides, debris flows, pyroclastic flows, riverbeds). While size-induced segregation has been well studied, the role of grain shape has not. Here we conduct numerical experiments to investigate how grain shape affects granular segregation in dry and wet flows. To isolate the former, we compare dry, bidisperse mixtures of spheres alone with mixtures of spheres and cubes in a rotating drum. Results show that while segregation level generally increases with particle size ratio, the presence of cubes decreases segregation levels compared to cases with only spheres. Further, we find differences in the segregation level depending on which shape makes up each size class, reflecting differences in mobility when smaller grains are cubic or spherical. We find similar dynamics in simulations of a shear-driven coupled fluid-granular flow (e.g., a simulated riverbed), demonstrating that this phenomenon is not unique to rotating drums; however, in contrast to the dry system, we find that the segregation level increases in the presence of cubic grains, and fluid drag effects can qualitatively change segregation trends. Our findings demonstrate competing shape-induced segregation patterns in wet and dry flows that are independent from grain size controls, with implications for many industrial and geophysical processes.

Soft matter physics of the ground beneath our feet.

The soft part of the Earth's surface - the ground beneath our feet - constitutes the basis for life and natural resources, yet a general physical understanding of the ground is still lacking. In this critical time of climate change, cross-pollination of scientific approaches is urgently needed to better understand the behavior of our planet's surface. The major topics in current research in this area cross different disciplines, spanning geosciences, and various aspects of engineering, material sciences, physics, chemistry, and biology. Among these, soft matter physics has emerged as a fundamental nexus connecting and underpinning many research questions. This perspective article is a multi-voice effort to bring together different views and approaches, questions and insights, from researchers that work in this emerging area, the soft matter physics of the ground beneath our feet. In particular, we identify four major challenges concerned with the dynamics in and of the ground: (I) modeling from the grain scale, (II) near-criticality, (III) bridging scales, and (IV) life. For each challenge, we present a selection of topics by individual authors, providing specific context, recent advances, and open questions. Through this, we seek to provide an overview of the opportunities for the broad Soft Matter community to contribute to the fundamental understanding of the physics of the ground, strive towards a common language, and encourage new collaborations across the broad spectrum of scientists interested in the matter of the Earth's surface.

Arctic soil patterns analogous to fluid instabilities.

Slow-moving arctic soils commonly organize into striking large-scale spatial patterns called solifluction terraces and lobes. Although these features impact hillslope stability, carbon storage and release, and landscape response to climate change, no mechanistic explanation exists for their formation. Everyday fluids-such as paint dripping down walls-produce markedly similar fingering patterns resulting from competition between viscous and cohesive forces. Here we use a scaling analysis to show that soil cohesion and hydrostatic effects can lead to similar large-scale patterns in arctic soils. A large dataset of high-resolution solifluction lobe spacing and morphology across Norway supports theoretical predictions and indicates a newly observed climatic control on solifluction dynamics and patterns. Our findings provide a quantitative explanation of a common pattern on Earth and other planets, illuminating the importance of cohesive forces in landscape dynamics. These patterns operate at length and time scales previously unrecognized, with implications toward understanding fluid-solid dynamics in particulate systems with complex rheology.

Disability disclosure as an impression management technique used in the workplace: A grounded theory investigation.

BACKGROUND: In order to overcome obstacles to entry and inclusion in the workplace, individuals with disabilities engage in various impression management strategies to present themselves as the socially acceptable 'ideal employee.' OBJECTIVE: This study expands on previous disclosure research by asking individuals with disabilities to share their experiences of identity management and workplace challenges. METHODS: We leveraged qualitative research techniques to explore the reciprocal impact of workplace treatment and disclosure. RESULTS: Impression management emerged as an especially salient aspect of participants' disclosure decisions, and participants used an array of impression management tactics. Some employees with disabilities described positive experiences; however, we also learned that impression management can present unique challenges that may outweigh potential benefits. CONCLUSION: Our findings affirm that managing the image we project can be remarkably complicated and effortful when having a disability. This paper concludes with implementation recommendations for vocational rehabilitation counselors and human resource practitioners.

Analysis of Health Disparities in the Screening and Diagnosis of Hearing Loss: Early Hearing Detection and Intervention Hearing Screening Follow-Up Survey.

PURPOSE: The purpose of this study was to (a) provide introductory literature regarding cultural constructs, health disparities, and social determinants of health (SDoH); (b) summarize the literature regarding the Centers for Disease Control and Prevention (CDC) Early Hearing Detection and Intervention (EHDI) Hearing Screening Follow-Up Survey (HSFS) data; (c) explore the CDC EHDI HSFS data regarding the contribution of maternal demographics to loss-to-follow-up/loss-to-documentation (LTF/D) between hearing screening and audiologic diagnosis for 2016, 2017, and 2018; and (d) examine these health disparities within the context of potential ethnoracial biases. METHOD: This is a comprehensive narrative literature review of cultural constructs, hearing health disparities, and SDoH as they relate to the CDC EHDI HSFS data. We explore the maternal demographic data reported on the CDC EHDI website and report disparities for maternal age, education, ethnicity, and race for 2016, 2017, and 2018. We focus on LTF/D for screening and diagnosis within the context of racial and cultural bias. RESULTS: A literature review demonstrates the increase in quality of the CDC EHDI HSFS data over the past 2 decades. LTF/D rates for hearing screening and audiologic diagnostic testing have improved from higher than 60% to current rates of less than 30%. Comparisons of diagnostic completion rates reported on the CDC website for the EHDI HSFS 2016, 2017, and 2018 data show trends for maternal age, education, and race, but not for ethnicity. Trends were defined as changes more than 10% for variables averaged over a 3-year period (2016-2018). CONCLUSIONS: Although there have been significant improvements in LTF/D over the past 2 decades, there continue to be opportunities for further improvement. Beyond neonatal screening, delays continue to be reported in the diagnosis of young children with hearing loss. Notwithstanding the extraordinarily diverse families within the United States, the imperative is to minimize such delays so that all children with hearing loss can, at the very least, have auditory accessibility to spoken language by 3 months of age. Conscious awareness is essential before developing a potentially effective plan of action that might remediate the problem.

Training School Professionals in a Global Pandemic: Insights From Elementary Education and Speech-Language Pathology.

PURPOSE: The purpose of this research was to explore the preparation of practitioners from two disciplines-speech-language pathology and elementary education-who often work together in a school setting to identify ways to best support future professionals in their educational practicum settings. The primary research questions guiding this investigation were as follows: Did the student teaching and supervision experiences of preservice K-6 teachers (PSTs) and their mentors and speech-language pathology graduate student clinicians and their supervisors differ during the COVID-19 pandemic, and if so, in what ways? METHOD: A total of 54 participants from one university participated in this study from four groups: 15 graduate student clinicians in a speech-language pathology program, 14 speech-language pathology supervisors, 14 PSTs, and 11 teacher mentors. Survey questions were designed to capture the perceptions of students and supervisors in the fields of speech-language pathology and elementary education who were in the school setting during the fall 2020 semester. Quantitative and qualitative questions were included to obtain information related to the following areas: planning, environment, supervision preferences, team experiences, professional development, and telepractice. RESULTS: Speech-language pathologists and teacher mentors reported being able to successfully mentor and supervise students in the school setting despite significant challenges presented by the global pandemic. Findings also identified several significant differences in the experiences of PSTs and speech-language pathology graduate student clinicians who were in the schools for field experiences. CONCLUSIONS: Overall, speech-language pathology graduate student clinicians and their supervisors as well as PSTs and their teacher mentors reported adequately navigating their field experiences during the COVID-19 pandemic. Implications for how these findings can inform professional preparation programs to optimize future educational and therapy outcomes for students are discussed.