• Excited bottomonia in quark-gluon plasma from lattice QCD

      Larsen, Rasmus; Meinel, Stefan; Mukherjee, Swagato; Petreczky, Peter; Univ Arizona, Dept Phys (ELSEVIER, 2020-11-26)
      We present the first lattice QCD study of up to 3S and 2P bottomonia at non-zero temperatures. Correlation functions of bottomonia were computed using novel bottomonium operators and a variational technique, within the lattice non-relativistic QCD framework. We analyzed the bottomonium correlation functions based on simple physically-motivated spectral functions. We found evidence of sequential in-medium modifications, in accordance with the sizes of the bottomonium states.
    • Superiority of Bayes estimators over the MLE in high dimensional multinomial models and its implication for nonparametric Bayes theory

      Bhattacharya, Rabi; Oliver, Rachel; Univ Arizona, Dept Math (ELSEVIER, 2020-10)
      The performance of Bayes estimators is examined, in comparison with the MLE, in multinomial models with a relatively large number of cells. The prior for the Bayes estimator is taken to be the conjugate Dirichlet, i.e., the multivariate Beta, with exchangeable distributions over the coordinates, including the non-informative uniform distribution. The choice of the multinomial is motivated by its many applications in business and industry, but also by its use in providing a simple nonparametric estimator of an unknown distribution. It is striking that the Bayes procedure outperforms the asymptotically efficient MLE over most of the parameter spaces for even moderately large dimensional parameter spaces and rather large sample sizes. (C) 2020 Elsevier B.V. All rights reserved.
    • Sparse subsurface radar reflectors in Hellas Planitia, Mars

      Cook, Claire W.; Bramson, Ali M.; Byrne, Shane; Holt, John W.; Christoffersen, Michael S.; Viola, Donna; Dundas, Colin M.; Goudge, Timothy A.; Univ Arizona, Lunar & Planetary Lab (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2020-09-15)
      Geomorphological features potentially related to subsurface ice, such as scalloped depressions, expanded craters, pedestal craters, and banded terrain, are present in and around Hellas Planitia, Mars. We present a radar survey of the region using the Shallow Radar (SHARAD) instrument on board the Mars Reconnaissance Orbiter (MRO) to identify candidate subsurface reflectors that may be due to the presence of potentially ice-rich deposits. We found that the majority of radar returns are likely from off-nadir surface topography ("clutter"), arising from the rough topography of the region. There is no widespread radar return from any subsurface interfaces. However, we identify a group of six reflectors adjacent to each other on a plateau in Malea Patera in which we have higher confidence. Landforms associated with a likely ice-rich mantle are associated with the plateau, but the thickness of this mantle does not correspond to the expected depth of the reflectors. However, layers beneath the mantle and marginal pitting at the edge of the plateau are similar to those associated with pedestal craters, which may be ice rich and are a similar thickness to the expected depth of the reflectors. Malea Patera has been interpreted to be a volcanic caldera, so the reflectors may be associated with a volcanic deposit within the plateau, although the evidence for this is inconclusive. Because this radar detection is localized and its origin ambiguous, we cannot use it to make conclusions about the thickness of subsurface deposits in the Hellas region as a whole. The lack of widespread radar reflectors in this region, as compared to the northern mid-latitudes where extensive radar reflections have been mapped, may be due in part to higher surface roughness, which creates radar clutter that may obscure subsurface reflectors. However on the southern rim of the basin and south of the basin, the lack of reflectors may indicate that the possible ice-rich deposits observed geomorphologically in this region are too thin to be resolved by SHARAD, are dielectrically similar to the underlying unit, or have a gradual vertical transition in ice content that is not reflective for the radar. This would imply that recent climate processes may have favored widespread, thick ice deposition or preservation in the northern hemisphere as compared to the southern hemisphere.
    • Simulated microgravity disarms human NK-cells and inhibits anti-tumor cytotoxicity in vitro

      Mylabathula, Preteesh Leo; Li, Li; Bigley, Austin B.; Markofski, Melissa M.; Crucian, Brian E.; Mehta, Satish K.; Pierson, Duane L.; Laughlin, Mitzi S.; Rezvani, Katayoun; Simpson, Richard J.; et al. (PERGAMON-ELSEVIER SCIENCE LTD, 2020-09)
      Long-duration spaceflight impairs natural killer (NK) cell function, which could compromise immune surveillance in exploration class mission crew. To determine if microgravity can impair NK-cell function, we established a rotary cell culture system to expose human peripheral blood mononuclear cells to simulated microgravity (SMG) in vitro. We found that 12 h of SMG suppressed NK-cell cytotoxic activity (NKCA) by similar to 50% against K562, U266 and 721.221 tumor target cells when returned to the 1G environment. Mass cytometry was used to identify 37 individual markers associated with NK-cell activation, maturation and cytotoxicity, revealing that SMG causes reductions in NK-cell degranulation and effector cytokine production. Extended flow cytometry confirmed that SMG lowered NK cell perforin and granzyme b expression by 25% and 17% respectively, but did not affect the surface expression of various activating (NKG2D, NKp30) and inhibitory (NKG2A, KLRG1) receptors or the ability of NK-cells to conjugate with target cells. Flow cytometry further revealed that SMG impaired NK-cell degranulation (reduced CD107a+ expression) and suppressed TNF alpha and IFN gamma secretion in response to stimulation with K562 target cells. These findings indicate that SMG 'disarms' human NK-cells of cytolytic granules and impairs NKCA against a range of tumor target cells in vitro. Exposure to microgravity could be a factor that contributes to impaired NK-cell function during long duration space travel.
    • Pilot study of focus groups exploring student pharmacists' perceptions of a medication management center internship

      Axon, David R; Aljadeed, Raniah; Potisarach, Pemmarin; Forbes, Stephanie; DiLeo, Jessica; Warholak, Terri; Univ Arizona, Coll Pharm (ELSEVIER SCIENCE INC, 2020-09)
      Introduction: Student pharmacists are expected to participate in real-life, patient-centered experiences to help develop clinical knowledge and professional skills. This study explored student pharmacist intern perceptions of work experience at a medication management center (MMC). We also examined how working at the MMC helped fulfill curricular requirements, helped develop leadership skills, and provided professional development opportunities. Methods: Two focus groups were conducted with first-, second-, and third-year student pharmacist interns at the MMC in April 2019. The focus groups were audio recorded for verification purposes, transcribed, and analyzed thematically by two independent reviewers. Results: A total of five student pharmacist interns participated. Four main themes were identified: (1) knowledge; (2) communication; (3) time management; and (4) leadership, mentorship, and networking. Participants had opportunities to acquire new knowledge and skills outside the classroom, providing them an academic advantage while recognizing areas of deficiency. Students practiced communication skills that helped improve language skills and manage difficult patients, although telephonic consultations were challenging. Students learned to prioritize time with patients but reported difficulty managing their work schedules. Leadership, mentorship, and networking opportunities facilitated learning and improved their self-confidence. Conclusions: This qualitative analysis identified four key themes, highlighting the many benefits available for student pharmacist interns working at an academic-based MMC. Further research is needed to address challenges reported in this study and should include a larger sample of student pharmacists for more generalizable results.
    • Monte Carlo simulations of electron-sample interactions at phase boundaries and implications for automated mineralogy

      Barton, Isabel; Univ Arizona, Dept Min & Geol Engn; Univ Arizona, Dept Min & Geol Engn (PERGAMON-ELSEVIER SCIENCE LTD, 2020-08-15)
      Automated mineralogy instrumentation (QEMSCAN, MLA, TIMA) is routinely used for materials characterization in the mining industry. All current techniques identify minerals based on a combination of backscattered electron and chemical (energy-dispersive spectroscopy) signals read from the sample. Boundary zones, where two or more minerals are touching, yield signals that reflect a mix of the characteristics of multiple minerals and that may or may not match anything in the mineral database. These phase boundaries, varying in width, are known to cause errors in automated mineralogy analyses, but what mineral and boundary characteristics affect phase boundary width and how much error phase boundaries can cause remain poorly understood. New Monte Carlo modeling of electron-sample interactions at and near phase boundaries shows that the width of the zone of mixed signals, and hence the amount of error, depends on the grain size and texture of the sample; the densities of the minerals and the ionization potentials of their constituent elements; and the position and orientation of the boundary between the minerals, as well as various instrumental factors such as beam accelerating voltage. Error induced by phase boundaries is high when a high accelerating voltage is used to examine fine-grained samples with complex (intergrowth, exsolution) textures that involve low-density minerals with low-ionization-potential elements. Error is low when the sample is coarse-grained, lacks complex textural relationships that create boundary area, and consists of high-density minerals with high-ionization-potential elements, which have a higher electron stopping power and prevent the beam from spreading out as much. Where low- and high-density minerals are in contact at an angled boundary, the width of the boundary zone is low when the high-density mineral is on top and high when the low-density phase is on top. Calculations based on these simulations indicate that the amount of area that could fall within phase boundary zones depends strongly on grain size, shape, and width of boundary zone. Boundary phases may contribute significantly to overall analytical error for fine-grained minerals with low densities and composed of elements with low ionization potentials, but for most samples the boundary phase area is likely to be < 5% of the total surface area and the error relatively small. Errors induced by boundary phases will probably continue to annoy geometallurgists for some time, but with proper laboratory procedures for validating and cross-checking automated mineralogy results, they should not be a major component of error for most samples.
    • Imputation methods for addressing missing data in short-term monitoring of air pollutants

      Hadeed, Steven J; O'Rourke, Mary Kay; Burgess, Jefferey L; Harris, Robin B; Canales, Robert A; Univ Arizona, Mel & Enid Zuckerman Coll Publ Hlth; Univ Arizona, Interdisciplinary Program Appl Math (ELSEVIER, 2020-08-15)
      Monitoring of environmental contaminants is a critical part of exposure sciences research and public health practice. Missing data are often encountered when performing short-term monitoring (<24 h) of air pollutants with real-time monitors, especially in resource-limited areas. Approaches for handling consecutive periods of missing and incomplete data in this context remain unclear. Our aim is to evaluate existing imputation methods for handling missing data for real-time monitors operating for short durations. In a current field-study, realtime PM2.5 monitors were placed outside of 20 households and ran for 24-hours. Missing data was simulated in these households at four consecutive periods of missingness (20%, 40%, 60%, 80%). Univariate (Mean, Median, Last Observation Carried Forward, Kalman Filter, Random, Markov) and multivariate time-series (Predictive Mean Matching, Row Mean Method) methods were used to impute missing concentrations, and performance was evaluated using five error metrics (Absolute Bias, Percent Absolute Error in Means, R2 Coefficient of Determination, Root Mean Square Error, Mean Absolute Error). Univariate methods of Markov, random, and mean imputations were the best performingmethods that yielded 24-hour mean concentrations with the lowest error and highest R2 values across all levels of missingness. When evaluating error metrics minute-by-minute, Kalman filters, median, and Markov methods performed well at low levels of missingness (20-40%). However, at higher levels of missingness (60-80%), Markov, random, median, and mean imputation performed best on average. Multivariate methods were the worst performing imputation methods across all levels of missingness. Imputation using univariate methods may provide a reasonable solution to addressing missing data for short-term monitoring of air pollutants, especially in resource-limited areas. Further efforts are needed to evaluate imputation methods that are generalizable across a diverse range of study environments. (C) 2020 Elsevier B.V. All rights reserved.
    • Melanocortin 3 receptor activation with [D-Trp8]-γ-MSH suppresses inflammation in apolipoprotein E deficient mice

      Kadiri, James J; Thapa, Keshav; Kaipio, Katja; Cai, Minying; Hruby, Victor J; Rinne, Petteri; Univ Arizona, Dept Chem & Biochem (ELSEVIER, 2020-08-05)
      The melanocortin MC1 and MC3 receptors elicit anti-inflammatory actions in leukocytes and activation of these receptors has been shown to alleviate arterial inflammation in experimental atherosclerosis. Thus, we aimed to investigate whether selective targeting of melanocortin MC3 receptor protects against atherosclerosis. Apolipoprotein E deficient (ApoE-/-) mice were fed high-fat diet for 12 weeks and randomly assigned to receive either vehicle (n = 11) or the selective melanocortin MC3 receptor agonist [D-Trp(8)]-gamma-melanocyte-stimulating hormone ([D-Trp8]-γ-MSH; 15 μg/day, n = 10) for the last 4 weeks. Lesion size as well as macrophage and collagen content in the aortic root plaques were determined. Furthermore, leukocyte counts in the blood and aorta and cytokine mRNA expression levels in the spleen, liver and aorta were quantified. No effect was observed in the body weight development or plasma cholesterol level between the two treatment groups. However, [D-Trp8]-γ-MSH treatment significantly reduced plasma levels of chemokine (C-C motif) ligands 2, 4 and 5. Likewise, cytokine and adhesion molecule expression levels were reduced in the spleen and liver of γ-MSH-treated mice, but not substantially in the aorta. In line with these findings, [D-Trp8]-γ-MSH treatment reduced leukocyte counts in the blood and aorta. Despite reduced inflammation, [D-Trp8]-γ-MSH did not change lesion size, macrophage content or collagen deposition of aortic root plaques. In conclusion, the findings indicate that selective activation of melanocortin MC3 receptor by [D-Trp8]-γ-MSH suppresses systemic and local inflammation and thereby also limits leukocyte accumulation in the aorta. However, the treatment was ineffective in reducing atherosclerotic plaque size.
    • A mid-Cretaceous change from fast to slow exhumation of the western Chinese Altai mountains: A climate driven exhumation signal?

      Pullen, Alex; Banaszynski, Matthew; Kapp, Paul; Thomson, Stuart N.; Cai, Fulong; Univ Arizona, Dept Geosci (PERGAMON-ELSEVIER SCIENCE LTD, 2020-08-01)
      The Chinese Altai Mountains in western China are bound by Cenozoic transpressional strike-slip faults, many of which show Quaternary activity. To better understand how Mesozoic-Cenozoic deformation has affected the history of exhumation and uplift of the Chinese Altai Mountains, we collected Paleozoic granitoid samples for apatite fission track and apatite U-Th-Sm/He thermochronology. Central apatite fission track ages for N = 6 samples range from 68 to 104 Ma, whereas apatite U-Th-Sm/He ages range from 56 to 272 Ma for N = 23 samples (n = 80 individual analyses) across four transects in the western Chinese Altai. Our results indicate fast cooling during the late Early Cretaceous followed by slow cooling since. Thermal modeling results suggests < 2 km exhumation has occurred over most of the Chinese Altai since the Paleocene. If significant late Cenozoic surface uplift occurred in the Altai Mountains, as has been proposed, it must have been associated with minimal erosional exhumation. We suggest that the relief of the Chinese Altai largely developed during the late Mesozoic and denudation since has been minimal because of semi-arid climate conditions.
    • Optimization and Long-Term Stability of Micro Flow Sensors for Smart VP Shunts

      Edes, Gergo; Enikov, Eniko T.; Skoch, Jesse; Anton, Rein; Univ Arizona, Dept Aerosp & Mech Engn; Univ Arizona, Dept Surg (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2020-08-01)
      This paper reports on a systematic study of the flow sensitivity and resolution of micro-flow sensors intended for use in implantable ventricular-peritoneal shunts. The flow sensors utilize ferromagnetic flaps (transducers) whose deflection is detected by ultra-sensitive MTJ sensors (20mV/V/Oe). A working range of 0-40 ml/h was demonstrated at a maximum uncertainty of 4% RMS and a resolution of 0.4 ml/h. Earlier studies on this sensor unveiled significant low-frequency noise (drift) limiting the sensitivity to 1.4 ml/hr. The present study identifies thermal noise as the main source of low-frequency drift. Using thermal compensation it was found that the drift can be reduced below 2 ml per 24-hr. Combining an array of four transducers operating in series, it has been demonstrated that a sensitivity can be increased 10.9 fold. Furthermore, the report examines the long-term structural stability of the sensors and produces a corrosion report suggesting a lifespan of 15 to 55 years.
    • The sedimentological evolution and petroleum potential of a very thick Upper Cretaceous marine mudstone succession from the southern high latitudes—a case study from the Bight Basin, Australia

      Wainman, Carmine C.; Tagliaro, Gabriel; Jones, Matthew M.; Charles, Adam J.; Hall, Tony; White, Lloyd T.; Bogus, Kara A.; Wolfgring, Erik; O'Connor, Lauren K.; McCabe, Peter J.; et al. (ELSEVIER SCI LTD, 2020-08)
      During IODP Expedition 369, a 690 m thick succession of silty claystone spanning the early Turonian to the late Santonian was encountered at Site U1512 in the Bight Basin, offshore southern Australia. Stacking patterns, sedimentary facies and palynological assemblages reveal that the succession was rapidly deposited with hyperpycnal and hypopycnal flows in a marine prodelta setting, which was subject to basin restriction. The dominance of clay-rich facies and phytoclasts in the succession was likely the result of a major river system delivering a high sediment load into the Bight Basin when a warm, wet climate prevailed. A combination of high sedimentation rates (19-272 m/Myr) and accelerated subsidence prevented the delta from rapidly prograding into more distal regions of the basin. The complete Turonian to Santonian mudstone succession yields low total organic carbon (similar to 1 wt%) and Type IV kerogens. However, palynofacies assemblages become progressively marine in character and total organic carbon values vary between 1 and 1.5 wt% with depth. This may indicate that the base of the hole at Site U1512 was close to potential organic-rich black shales associated with Ocean Anoxic Event 2. Low amplitude and irregular reflections on seismic data and disparities between biostratigraphic zonations suggest the upper 350 m of the Turonian to Santonian succession may represent a mass movement that happened during the Pleistocene. This study reveals that Site U1512 material likely represents a near-stratigraphically complete marine mudstone succession from high paleolatitudes, as well as the only depositional record that was fully cored from the Bight Basin.
    • Improving transportation impact analyses for subsidized affordable housing developments: A data collection and analysis of motorized vehicle and person trip generation

      Currans, Kristina M.; Abou-Zeid, Gabriella; Clifton, Kelly J.; Howell, Amanda; Schneider, Robert; Univ Arizona, Coll Architecture Planning & Landscape Architectu (ELSEVIER SCI LTD, 2020-08)
      Transportation impact analyses begin with a trip generation estimation process-estimating motorized vehicle and person trip counts coming and going from the proposed site. Data commonly used is often insensitive to urban contexts (such as employment densities) and socioeconomic conditions. This insensitivity results in sometimes exaggerated estimates, an increase associated transportation impact fees, and a need for additional mitigation of impacts which may further hinder land development. In this study, we collected and analyzed person and motorized vehicle count data from 26 affordable housing developments in Los Angeles and San Francisco. Counts were regressed upon site and built environment characteristics known to influence site-level travel behavior (e.g., parking supply, employment density), and regressions were validated using externally collected data. The findings indicate the average square footage of dwelling units, parking ratios, and nearby retail employment densities to be important predictors. The findings also indicate that increasing the parking supply from one space to two for each dwelling unit will result in a significant predicted increase of approximately 0.26 and 0.18 motorized vehicle trips per dwelling unit for AM and PM peak periods, respectively. These findings reiterate the need for trip generation methodologies sensitive to the built environment and socio-demographics.
    • Implications for the origin and evolution of Martian Recurring Slope Lineae at Hale crater from CaSSIS observations

      Munaretto, G.; Pajola, M.; Cremonese, G.; Re, C.; Lucchetti, A.; Simioni, E.; McEwen, A.S.; Pommerol, A.; Becerra, P.; Conway, S.J.; et al. (PERGAMON-ELSEVIER SCIENCE LTD, 2020-08)
      Recurring Slope Lineae (RSL) are narrow, dark features that typically source from rocky outcrops, incrementally lengthen down Martian steep slopes in warm seasons, fade in cold seasons and recur annually. In this study we report the first observations of RSL at Hale crater, Mars, during late southern summer by the Color and Surface Science Imaging System (CaSSIS) on board ESA's ExoMars Trace Gas Orbiter (TGO). For the first time, we analyze images of RSL acquired during morning solar local times and compare them with High Resolution Imaging Science Experiment (HiRISE) observations taken in the afternoon. We find that RSL activity is correlated with the presence of steep slopes. Our thermal analysis establishes that local temperatures are high enough to allow either the melting of brines or deliquescence of salts during the observation period, but the slope and aspect distributions of RSL activity predicted by these processes are not consistent with our observations. We do not find any significant relative albedo difference between morning and afternoon RSL. Differences above 11% would have been detected by our methodology, if present. This instead suggests that RSL at Hale crater are not caused by seeping water that reaches the surface, but are best explained as dry flows of granular material.
    • Administering the HPV Vaccine to People Living with HIV: Providers' Perspectives

      Koskan, Alexis; Brennhofer, Stephanie A; Helitzer, Deborah; Univ Arizona, Mel & Enid Zuckerman Coll Publ Hlth (SPRINGER, 2020-08)
      HIV-positive patients suffer disproportionate burden of anal cancer, a disease which is primarily caused by persistent infection with human papillomavirus (HPV) and is potentially preventable with the completion of the HPV vaccine series. Past research qualitatively explored HIV-positive patients' perspectives about the HPV vaccine. However, little is known about their healthcare practitioners' vaccine recommendation behaviors, the strongest influence on vaccine uptake. This study reports on in-depth interviews conducted with 25 healthcare practitioners who provide care for HIV-positive patients. Qualitative themes that emerged from the study included clinicians' HPV vaccination behaviors, HIV patient's willingness to get the HPV vaccine, the role of HIV-positive patients' immune functioning in terms of timing of HPV vaccine administration, and vaccinating HIV-positive patients over age 26. The majority of providers offered the vaccine at their healthcare facility. Participants varied in their opinions related to the importance of patients' CD4 count in terms of timing of HPV vaccine administration; some believed that patients' immune functioning should first be stabilized to receive the most benefit from the vaccine series. They also differed in the perceived benefit of offering the vaccine to patients over age 26. In light of the U.S. Food and Drug Administration's recent approval to extend HPV vaccination to adults up to age 45 years, more HIV-positive adults may benefit by receiving this vaccine series. Future efforts should ensure that providers regularly promote the HPV vaccine to their adult HIV-positive patients. Vaccinating HIV-positive patients may help reduce the burden of HPV-related cancers, particularly anal cancer.
    • ‘Personality in Its Natural Habitat’ Revisited: A Pooled, Multi‐sample Examination of the Relationships Between the Big Five Personality Traits and Daily Behaviour and Language Use

      Tackman, Allison M.; Baranski, Erica N.; Danvers, Alexander F.; SBARRA, DAVID A.; Raison, Charles L.; Moseley, Suzanne A.; Polsinelli, Angelina J.; Mehl, Matthias R.; Univ Arizona, Dept Psychol (WILEY, 2020-07-16)
      Past research using the Electronically Activated Recorder (EAR), an observational ambulatory assessment method for the real-world measurement of daily behaviour, has identified several behavioural manifestations of the Big Five domains in a small college sample (N = 96). With the use of a larger and more diverse sample of pooled data from N = 462 participants from a total of four community samples who wore the EAR from 2 to 6 days, the primary purpose of the present study was to obtain more precise and generalizable effect estimates of the Big Five-behaviour relationships and to re-examine the degree to which these relationships are gender specific. In an extension of the original article, the secondary purpose of the present study was to examine if the Big Five-behaviour relationships differed across two facets of each Big Five domain. Overall, while several of the behavioural manifestations of the Big Five were generally consistent with the trait definitions (replicating some findings from the original article), we found little evidence of gender differences (not replicating a basic finding from the original article). Unique to the present study, the Big Five-behaviour relationships were not always comparable across the two facets of each Big Five domain. (C) 2020 European Association of Personality Psychology
    • Correlates of cognitive impairment in adult cancer survivors who have received chemotherapy and report cognitive problems

      Gutenkunst, Shannon L; Vardy, Janette L; Dhillon, Haryana M; Bell, Melanie L; Univ Arizona, Stat Grad Interdisciplinary Program; Univ Arizona, Mel & Enid Zuckerman Coll Publ Hlth, Dept Epidemiol & Biostat (SPRINGER, 2020-07-14)
      Objective Cognitive impairment negatively affects some cancer survivors who have completed chemotherapy; however, factors underlying this cognitive impairment remain poorly understood. We aimed to investigate (1) the relative importance of demographics, medical, and psychological characteristics associated with cognitive impairment and (2) the specific variables associated with cognitive impairment in adult cancer survivors who completed adjuvant chemotherapy. Methods We performed post hoc analyses of baseline data from early-stage cancer survivors with cognitive complaints who received adjuvant chemotherapy 0.5-5 years earlier and volunteered for a trial designed to improve cognition. The primary outcome of self-reported cognitive impairment was measured using a questionnaire; secondary outcome of objective cognitive impairment was measured using a computerized neuropsychological test battery. Hierarchical linear regression determined the relative importance of demographics, medical, and psychological characteristics in associations with both self-reported and objective cognitive impairment. Results The sample was 95% female and 89% breast cancer patients. The final model accounted for 33% of variation in self-reported cognitive impairment (n = 212, demographics 5%, medical 3%, and psychological 25%), with fatigue and stress as significant individual correlates (pvalues <= 0.0001). For the secondary analysis, the final model accounted for 19% of variation in objective cognitive impairment (n = 206, demographics 10%, medical 5%, and psychological 4%), with age, smoking history, and number of chemotherapy cycles as significant individual correlates. Conclusion We found that psychological characteristics are more important than demographic and medical characteristics in self-reported cognitive impairment, whereas other characteristics are more important in objective cognitive impairment. This suggests clinicians should investigate possible psychological problems in cancer survivors who self-report cognitive impairment.
    • Radiative and Nonradiative Recombinations in Organic Radical Emitters: The Effect of Guest–Host Interactions

      Abroshan, Hadi; Coropceanu, Veaceslav; Brédas, Jean‐Luc; Univ Arizona, Dept Chem & Biochem (WILEY-V C H VERLAG GMBH, 2020-07-09)
      Radical-carrying organic molecules have received significant attention to bypass the issue related to harvesting triplet excitons in current light-emitting materials. While the computational efforts conducted so far have treated these radical emitters as isolated entities, in actual devices, they are embedded in a host matrix and subject to emitter-host interactions. Here, by combining molecular dynamics simulations and density functional theory calculations, the impact of the host matrix on the optoelectronic performance of radical emitters is evaluated, taking as a representative example the (4-ncarbazolyl-2,6-dichlorophenyl)bis(2,4,6-trichlorophenyl)-methyl (TTM-3NCz) radical emitter dispersed in a 4,4-bis(carbazol-9-yl)biphenyl (CBP) host. A morphological analysis shows that steric effects around the radical centers, carried by the TTM electron-poor moieties of the emitters, disfavor pi-pi interactions with the host molecules, which leads to random intermolecular orientations around the TTM moieties. The 3NCz electron-rich moieties of the emitters, however, have much lesser spatial hindrance for intermolecular pi-pi stacking, which modulates the structural and electronic properties of the emitters in the host matrix. The influence of dynamic and static disorders on the radiative and nonradiative recombination processes is also investigated and it is found that the rates of nonradiative recombination are small, which opens the way to 100% internal quantum efficiency for the doublet-based emission process.
    • Flat bands in twisted bilayer transition metal dichalcogenides

      Zhang, Zhiming; Wang, Yimeng; Watanabe, Kenji; Taniguchi, Takashi; Ueno, Keiji; Tutuc, Emanuel; LeRoy, Brian J.; Univ Arizona, Dept Phys (NATURE PUBLISHING GROUP, 2020-07-06)
      Using scanning tunnelling spectroscopy, the flat bands in twisted bilayer WSe(2)are shown near both 0 degrees and 60 degrees twist angles. The crystal structure of a material creates a periodic potential that electrons move through giving rise to its electronic band structure. When two-dimensional materials are stacked, the resulting moire pattern introduces an additional periodicity so that the twist angle between the layers becomes an extra degree of freedom for the resulting heterostructure. As this angle changes, the electronic band structure is modified leading to the possibility of flat bands with localized states and enhanced electronic correlations(1-6). In transition metal dichalcogenides, flat bands have been theoretically predicted to occur for long moire wavelengths over a range of twist angles around 0 degrees and 60 degrees (ref.(4)) giving much wider versatility than magic-angle twisted bilayer graphene. Here, we show the existence of a flat band in the electronic structure of 3 degrees and 57.5 degrees twisted bilayer WSe(2)samples using scanning tunnelling spectroscopy. Our direct spatial mapping of wavefunctions at the flat-band energy show that the localization of the flat bands is different for 3 degrees and 57.5 degrees, in agreement with first-principles density functional theory calculations(4).
    • Fostering Participation During Literacy Instruction in Inclusive Classrooms for Students With Complex Support Needs: Educators’ Strategies and Perspectives

      Zagona, Alison L.; Lansey, Kirsten R.; Kurth, Jennifer A.; Kuhlemeier, Alena; Univ Arizona (SAGE PUBLICATIONS INC, 2020-07-03)
      Existing research has documented evidence-based practices that are effective for supporting students with complex support needs (CSN) to learn academic skills. However, there is a need to learn more about effective instructional strategies for students with CSN during literacy lessons in general education classrooms. In addition, there is a need to understand general education teachers' perspectives on these strategies, including how they learned about them. The purpose of this study was to understand (a) the extent of participation of students with CSN in literacy instruction and activities in general education classrooms, (b) the supports educators provide during these activities, and (c) how educators learned about the strategies they use in their classrooms. We observed nine students with CSN and conducted follow-up interviews with their classroom teachers. Overall, students participated in academic activities for a majority of observations, and these activities addressed a variety of different literacy skills. Educators used research-based instructional practices to support the students including prompts and visual supports. During follow-up interviews, general education teachers described the strategies they used to support students with CSN, and they described how they learned about these strategies. Implications for future research and practice are presented.
    • The Society of Behavioral Sleep Medicine (SBSM) COVID-19 Task Force: Objectives and Summary Recommendations for Managing Sleep during a Pandemic

      Crew, Earl Charles; Baron, Kelly Glazer; Grandner, Michael A; Ievers-Landis, Carolyn E; McCrae, Christina S; Nadorff, Michael R; Nowakowski, Sara; Ochsner Margolies, Skye; Hansen, Kathryn; Univ Arizona, Coll Med, Dept Psychiat (ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2020-07-03)
      As a response to clinical observations that the pervasive stress and social/environmental disruptions from the 2020 COVID-19 pandemic have also impacted sleep, the Society of Behavioral Sleep Medicine (SBSM) convened the COVID-19 Task Force with goals to identify and disseminate information that could be useful in addressing sleep concerns during this crisis. Participants Members of the SBSM COVID-19 Task Force. Results/Conclusions Herein is a summary of the resources developed by the SBSM COVID-19 Task force, which includes links to online materials developed for use by providers and patients, as well as brief descriptions of key recommendations by the Task Force for specific sleep conditions (e.g., acute insomnia, nightmares) and vulnerable populations (e.g., parents, essential/healthcare workers, older adults).