Now showing items 21-40 of 8472

    • Effective field theory for two-body systems with shallow S-wave resonances

      Habashi, J. Balal; Fleming, S.; Sen, S.; van Kolck, U.; Univ Arizona, Dept Phys (Elsevier BV, 2020-11)
      Resonances are of particular importance in the scattering of composite particles in quantum mechanics. We build an effective field theory for two-body scattering which includes a low-energy S-wave resonance. Our starting point is the most general La-grangian with short-range interactions. We demonstrate that these interactions can be organized into various orders so as to generate a systematic expansion for an S matrix with two low energy poles. The pole positions are restricted by renormalization at leading order, where the common feature is a non-positive effective range. We carry out the expansion explicitly to next to-leading order and illustrate how it systematically accounts for the results of a toy model - a spherical well with a delta shell at its border. (C) 2020 Elsevier Inc. All rights reserved.
    • Moderate-resolution K-band Spectroscopy of Substellar Companion κ Andromedae b

      Wilcomb, Kielan K.; Konopacky, Quinn M.; Barman, Travis S.; Theissen, Christopher A.; Ruffio, Jean-Baptiste; Brock, Laci; Macintosh, Bruce; Marois, Christian; Univ Arizona, Lunar & Planetary Lab (IOP PUBLISHING LTD, 2020-10-15)
      We present moderate-resolution (R similar to 4000) K-band spectra of the "super-Jupiter,"kappa Andromedae b. The data were taken with the OSIRIS integral field spectrograph at Keck Observatory. The spectra reveal resolved molecular lines from H2O and CO, and are compared to a custom PHOENIX atmosphere model grid appropriate for young planetary-mass objects. We fit the data using a Markov chain Monte Carlo forward-modeling method. Using a combination of our moderate-resolution spectrum and low-resolution, broadband data from the literature, we derive an effective temperature of T-eff = 1950-2150 K, a surface gravity of log g = 3.5-4.5, and a metallicity of [M/H] = -0.2-0.0. These values are consistent with previous estimates from atmospheric modeling and the currently favored young age of the system (<50 Myr). We derive a C/O ratio of 0.70(-0.24)(+0.09) for the source, broadly consistent with the solar C/O ratio. This, coupled with the slightly subsolar metallicity, implies a composition consistent with that of the host star, and is suggestive of formation by a rapid process. The subsolar metallicity of kappa Andromedae b is also consistent with predictions of formation via gravitational instability. Further constraints on formation of the companion will require measurement of the C/O ratio of kappa Andromedae A. We also measure the radial velocity of kappa Andromedae b for the first time, with a value of -1.4 +/- 0.9 km s(-1) relative to the host star. We find that the derived radial velocity is consistent with the estimated high eccentricity of kappa Andromedae b.
    • The TESS Phase Curve of KELT-1b Suggests a High Dayside Albedo

      Beatty, Thomas G.; Wong, Ian; Fetherolf, Tara; Line, Michael R.; Shporer, Avi; Stassun, Keivan G.; Ricker, George R.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; et al. (IOP PUBLISHING LTD, 2020-10-20)
      We measured the optical phase curve of the transiting brown dwarf KELT-1b (TOI 1476) using data from the TESS spacecraft. We found that KELT-1b shows significant phase variation in the TESS bandpass, with a relatively large phase amplitude of 234(-44)(+43) ppm and a secondary eclipse depth of 399 +/- 19 ppm. We also measured a marginal eastward offset in the dayside hot spot of 18.degrees 3 +/- 7.degrees 4 relative to the substellar point. We detected a strong phase-curve signal attributed to ellipsoidal distortion of the host star with an amplitude of 399 19 ppm. Our results are roughly consistent with the Spitzer phase curves of KELT-1b, but the TESS eclipse depth is deeper than expected. Our cloud-free 1D models of KELT-1b's dayside emission are unable to fit the full combined eclipse spectrum. Instead, the large TESS eclipse depth suggests that KELT-1b may have a significant dayside geometric albedo of A(g) similar to 0.5 in the TESS bandpass, which would agree with the tentative trend between equilibrium temperature and geometric albedo recently suggested by Wong et al. We posit that if KELT-1b has a high dayside albedo, it is likely due to silicate clouds that form on KELT-1b's nightside and are subsequently transported onto the western side of KELT-1b's dayside hemisphere before breaking up.
    • The use of positive end expiratory pressure in patients affected by COVID-19: Time to reconsider the relation between morphology and physiology

      Perchiazzi, Gaetano; Pellegrini, Mariangela; Chiodaroli, Elena; Urits, Ivan; Kaye, Alan D; Viswanath, Omar; Varrassi, Giustino; Puntillo, Filomena; Univ Arizona, Dept Anesthesiol, Coll Med Phoenix (ELSEVIER, 2020-07-18)
      Coronavirus disease 2019 (COVID-19) is a new disease with different phases that can be catastrophic for subpopulations of patients with cardiovascular and pulmonary disease states at baseline. Appreciation for these different phases and treatment modalities, including manipulation of ventilatory settings and therapeutics, has made it a less lethal disease than when it emerged earlier this year. Different aspects of the disease are still largely unknown. However, laboratory investigation and clinical course of the COVID-19 show that this new disease is not a typical acute respiratory distress syndrome process, especially during the first phase. For this reason, the best strategy to be applied is to treat differently the single phases and to support the single functions of the failing organs as they appear. (C) 2020 The Authors. Published by Elsevier Ltd.
    • Tempestad: una Cartografía Corporal de la Violencia

      Cornide, Ana; Univ Arizona (UNIV NACIONAL LA PAMPA, FAC CIENCIAS HUMANAS, 2020-09-01)
      Este artículo parte de una crítica sobre la violencia y su relación con el arte y examina cómo Tatiana Huezo en su última película documental, Tempestad (2016), crea una estética que funciona como una respuesta a los modos contemporáneos de producción y socialización de la violencia visual, así como a la deshumanización de las víctimas en la realidad de la violencia del México del siglo XXI, derivada del poder militarizado de sus fronteras y la denominada “guerra contra el narcotráfico”. Huezo se centra específicamente en la desechabilidad biopolítica de los cuerpos de las mujeres, sujetas a la precarización de la justicia, cuyo síntoma es la impunidad creada por la negligencia sistémica del Estado. This article uses a critique of violence and its relationship to art to examine how Tatiana Huezo in her latest documentary film, Tempestad (2016), creates an aesthetic that functions as a response to contemporary modes of production and socialization of visual violence, as well as the dehumanization of victims, situated in the violence of contemporary Mexico that results from its militarized borders and the so-called “war on drug trafficking.” Huezo focuses specifically on the biopolitical disposability of women’s bodies, subjected to the precariousness of justice, whose symptom is the impunity that comes from the systemic neglect of the state.
    • The MOSDEF Survey: The First Direct Measurements of the Nebular Dust Attenuation Curve at High Redshift

      Reddy, Naveen A.; Shapley, Alice E.; Kriek, Mariska; Steidel, Charles C.; Shivaei, Irene; Sanders, Ryan L.; Mobasher, Bahram; Coil, Alison L.; Siana, Brian; Freeman, William R.; et al. (IOP PUBLISHING LTD, 2020-10-20)
      We use a sample of 532 star-forming galaxies at redshifts z similar or equal to 1.4-2.6 with deep rest-frame optical spectra from the MOSFIRE Deep Evolution Field (MOSDEF) survey to place the first constraints on the nebular attenuation curve at high redshift. Based on the first five low-order Balmer emission lines detected in the composite spectra of these galaxies (H alpha through H epsilon), we derive a nebular attenuation curve that is similar in shape to that of the Galactic extinction curve, suggesting that the dust covering fraction and absorption/scattering properties along the lines of sight to massive stars at high redshift are similar to those of the average Milky Way sight line. The curve derived here implies nebular reddening values that are, on average, systematically larger than those derived for the stellar continuum. In the context of stellar population synthesis models that include the effects of stellar multiplicity, the difference in reddening of the nebular lines and stellar continuum may imply molecular cloud crossing timescales that are a factor of greater than or similar to 3 ' longer than those inferred for local molecular clouds, star formation rates that are constant or increasing with time such that newly formed and dustier OB associations always dominate the ionizing flux, and/or that the dust responsible for reddening the nebular emission may be associated with nonmolecular (i.e., ionized and neutral) phases of the interstellar medium. Our analysis points to a variety of investigations of the nebular attenuation curve that will be enabled with the next generation of ground- and space-based facilities.
    • A Spectroscopic Survey of Lyα Emitters at z ≈ 3.1 over ∼1.2 Deg(2)

      Guo, Yucheng; Jiang, Linhua; Egami, Eiichi; Ning, Yuanhang; Zheng, Zhen-Ya; Ho, Luis C.; Univ Arizona, Steward Observ (IOP PUBLISHING LTD, 2020-10-21)
      We present a spectroscopic survey of Ly alpha emitters (LAEs) atz 3.1 in the Subaru XMM-Newton Deep Survey Field. This field has deep imaging data in a series of broad and narrow bands, including two adjacent narrow bands NB497 and NB503 that have allowed us to efficiently select LAE candidates atz 3.1. Using spectroscopic observations on MMT Hectospec and Magellan M2FS, we obtained a sample of 166 LAEs atz 3.1 over an effective area of similar to 1.2 deg(2), including 16 previously known LAEs. This is so far the largest (spectroscopically confirmed) sample of LAEs at this redshift. We make use of the secure redshifts and multiband data to measure spectral properties such as Ly alpha luminosity and rest-frame UV slope. We derive a robust Ly alpha luminosity function (LF) that spans a luminosity range from similar to 10(42.0)to >10(43.5)erg s(-1). Significant overdense and underdense regions are detected in our sample, but the area coverage is wide enough to largely suppress the effect from such cosmic variance. Our Ly alpha LF is generally consistent with those from previous studies atz similar to 3.1. At the brightest end of the LF, there is a tentative detection of a density excess that is not well described by the Schechter function. The comparison with the LFs at other redshifts suggests that the Ly alpha LF does not show significant evolution at 2 z < 5. Finally, we build the composite spectra of the LAEs and detect the Nv lambda 1239 and Civ lambda lambda 1548,1551 doublet emission lines at significance of similar to 4 sigma, suggesting very hard radiation fields in (some of) these LAEs.
    • Effect of pebble flux-regulated planetesimal formation on giant planet formation

      Voelkel, Oliver; Klahr, Hubert; Mordasini, Christoph; Emsenhuber, Alexandre; Lenz, Christian; Univ Arizona, Lunar & Planetary Lab (E D P SCIENCES S A, 2020-10-06)
      Context. The formation of gas giant planets by the accretion of 100 km diameter planetesimals is often thought to be inefficient. A diameter of this size is typical for planetesimals and results from self-gravity. Many models therefore use small kilometer-sized planetesimals, or invoke the accretion of pebbles. Furthermore, models based on planetesimal accretion often use the ad hoc assumption of planetesimals that are distributed radially in a minimum-mass solar-nebula way.Aims. We use a dynamical model for planetesimal formation to investigate the effect of various initial radial density distributions on the resulting planet population. In doing so, we highlight the directive role of the early stages of dust evolution into pebbles and planetesimals in the circumstellar disk on the subsequent planet formation.Methods. We implemented a two-population model for solid evolution and a pebble flux-regulated model for planetesimal formation in our global model for planet population synthesis. This framework was used to study the global effect of planetesimal formation on planet formation. As reference, we compared our dynamically formed planetesimal surface densities with ad hoc set distributions of different radial density slopes of planetesimals.Results. Even though required, it is not the total planetesimal disk mass alone, but the planetesimal surface density slope and subsequently the formation mechanism of planetesimals that enables planetary growth through planetesimal accretion. Highly condensed regions of only 100 km sized planetesimals in the inner regions of circumstellar disks can lead to gas giant growth.Conclusions. Pebble flux-regulated planetesimal formation strongly boosts planet formation even when the planetesimals to be accreted are 100 km in size because it is a highly effective mechanism for creating a steep planetesimal density profile. We find that this leads to the formation of giant planets inside 1 au already by pure 100 km planetesimal accretion. Eventually, adding pebble accretion regulated by pebble flux and planetesimal-based embryo formation as well will further complement this picture.
    • Cool stars in the Galactic center as seen by APOGEE: M giants, AGB stars, and supergiant stars and candidates

      Schultheis, M.; Rojas-Arriagada, A.; Cunha, K.; Zoccali, M.; Chiappini, C.; Zasowski, G.; Queiroz, A. B. A.; Minniti, D.; Fritz, T.; García-Hernández, D. A.; et al. (E D P SCIENCES S A, 2020-10-08)
      The Galactic center region, including the nuclear disk, has until recently been largely avoided in chemical census studies because of extreme extinction and stellar crowding. Large, near-IR spectroscopic surveys, such as the Apache Point Observatory Galactic Evolution Experiment (APOGEE), allow the measurement of metallicities in the inner region of our Galaxy. Making use of the latest APOGEE data release (DR16), we are able for the first time to study cool Asymptotic Giant branch (AGB) stars and supergiants in this region. The stellar parameters of five known AGB stars and one supergiant star (VR 5-7) show that their location is well above the tip of the red giant branch. We studied metallicities of 157 M giants situated within 150 pc of the Galactic center from observations obtained by the APOGEE survey with reliable stellar parameters from the APOGEE pipeline making use of the cool star grid down to 3200 K. Distances, interstellar extinction values, and radial velocities were checked to confirm that these stars are indeed situated in the Galactic center region. We detect a clear bimodal structure in the metallicity distribution function, with a dominant metal-rich peak of [Fe/H] similar to +0.3 dex and a metal-poor peak around {Fe/H] = -0.5 dex, which is 0.2 dex poorer than Baade's Window. The alpha -elements Mg, Si, Ca, and O show a similar trend to the Galactic bulge. The metal-poor component is enhanced in the alpha -elements, suggesting that this population could be associated with the classical bulge and a fast formation scenario. We find a clear signature of a rotating nuclear stellar disk and a significant fraction of high-velocity stars with v(gal)> 300 km s(-1); the metal-rich stars show a much higher rotation velocity (similar to 200 km s(-1)) with respect to the metal-poor stars (similar to 140 km s(-1)). The chemical abundances as well as the metallicity distribution function suggest that the nuclear stellar disk and the nuclear star cluster show distinct chemical signatures and might be formed differently.
    • Mixed Messages: I. The Consequences of Communicating Negative Statements Within Emotional Support Messages to Cancer Patients

      Ray, Colter D; Floyd, Kory; Tietsort, Cris J; Veluscek, Alaina M; Otmar, Christopher D; Hashi, Emi C; Fisher, Rosalie; Univ Arizona, Dept Commun (SAGE PUBLICATIONS INC, 2019-09-09)
      This study tests if a negative statement occurring within an emotional support message affects cancer patients' perceptions of the effectiveness of the entire emotional support message as well as the perceived competence of the supporter communicating the emotional support message.
    • Continental-scale patterns of extracellular enzyme activity in the subsoil: an overlooked reservoir of microbial activity

      Dove, Nicholas C; Arogyaswamy, Keshav; Billings, Sharon A; Botthoff, Jon K; Carey, Chelsea J; Cisco, Caitlin; DeForest, Jared L; Fairbanks, Dawson; Fierer, Noah; Gallery, Rachel E; et al. (IOP PUBLISHING LTD, 2020-10-09)
      Chemical stabilization of microbial-derived products such as extracellular enzymes (EE) onto mineral surfaces has gained attention as a possibly important mechanism leading to the persistence of soil organic carbon (SOC). While the controls on EE activities and their stabilization in the surface soil are reasonably well-understood, how these activities change with soil depth and possibly diverge from those at the soil surface due to distinct physical, chemical, and biotic conditions remains unclear. We assessed EE activity to a depth of 1 m (10 cm increments) in 19 soil profiles across the Critical Zone Observatory Network, which represents a wide range of climates, soil orders, and vegetation types. For all EEs, activities per mass of soil correlated positively with microbial biomass (MB) and SOC, and all three of these variables decreased logarithmically with depth (p< 0.05). Across all sites, over half of the potential EE activities per mass soil consistently occurred below 20 cm for all measured EEs. Activities per unit MB or SOC were substantially higher at depth (soils below 20 cm accounted for 80% of whole-profile EE activity), suggesting an accumulation of stabilized (i.e. mineral sorbed) EEs in subsoil horizons. The pronounced enzyme stabilization in subsurface horizons was corroborated by mixed-effects models that showed a significant, positive relationship between clay concentration and MB-normalized EE activities in the subsoil. Furthermore, the negative relationships between soil C, N, and P and C-, N-, and P-acquiring EEs found in the surface soil decoupled below 20 cm, which could have also been caused by EE stabilization. This finding suggests that EEs may not reflect soil nutrient availabilities deeper in the soil profile. Taken together, our results suggest that deeper soil horizons hold a significant reservoir of EEs, and that the controls of subsoil EEs differ from their surface soil counterparts.
    • Sex-Dependent Pathology in the HPA Axis at a Sub-acute Period After Experimental Traumatic Brain Injury

      Bromberg, Caitlin E; Condon, Andrew M; Ridgway, Samantha W; Krishna, Gokul; Garcia-Filion, Pamela C; Adelson, P David; Rowe, Rachel K; Currier Thomas, Theresa; Univ Arizona, Coll Med Phoenix, Dept Child Hlth; Univ Arizona, Dept Biomed Informat, Coll Med Phoenix (FRONTIERS MEDIA SA, 2020-09-30)
      Over 2.8 million traumatic brain injuries (TBIs) are reported in the United States annually, of which, over 75% are mild TBIs with diffuse axonal injury (DAI) as the primary pathology. TBI instigates a stress response that stimulates the hypothalamic-pituitary-adrenal (HPA) axis concurrently with DAI in brain regions responsible for feedback regulation. While the incidence of affective symptoms is high in both men and women, presentation is more prevalent and severe in women. Few studies have longitudinally evaluated the etiology underlying late-onset affective symptoms after mild TBI and even fewer have included females in the experimental design. In the experimental TBI model employed in this study, evidence of chronic HPA dysregulation has been reported at 2 months post-injury in male rats, with peak neuropathology in other regions of the brain at 7 days post-injury (DPI). We predicted that mechanisms leading to dysregulation of the HPA axis in male and female rats would be most evident at 7 DPI, the sub-acute time point. Young adult age-matched male and naturally cycling female Sprague Dawley rats were subjected to midline fluid percussion injury (mFPI) or sham surgery. Corticotropin releasing hormone, gliosis, and glucocorticoid receptor (GR) levels were evaluated in the hypothalamus and hippocampus, along with baseline plasma adrenocorticotropic hormone (ACTH) and adrenal gland weights. Microglial response in the paraventricular nucleus of the hypothalamus indicated mild neuroinflammation in males compared to sex-matched shams, but not females. Evidence of microglia activation in the dentate gyrus of the hippocampus was robust in both sexes compared with uninjured shams and there was evidence of a significant interaction between sex and injury regarding microglial cell count. GFAP intensity and astrocyte numbers increased as a function of injury, indicative of astrocytosis. GR protein levels were elevated 30% in the hippocampus of females in comparison to sex-matched shams. These data indicate sex-differences in sub-acute pathophysiology following DAI that precede late-onset HPA axis dysregulation. Further understanding of the etiology leading up to late-onset HPA axis dysregulation following DAI could identify targets to stabilize feedback, attenuate symptoms, and improve efficacy of rehabilitation and overall recovery.
    • α-Cyperone Confers Antidepressant-Like Effects in Mice Neuroplasticity Enhancement by SIRT3/ROS Mediated NLRP3 Inflammasome Deactivation

      Xia, Baomei; Tong, Yue; Xia, Changbo; Chen, Chang; Shan, Xin; Univ Arizona, Coll Med Phoenix, Dept Basic Med Sci (FRONTIERS MEDIA SA, 2020-10-08)
      alpha-Cyperone (Cy) is a major active compound of Cyperus rotundus that has various pharmacological activities. But whether Cy possesses antidepressant effect is unknown. In this study, we exposed mice to chronic unpredictable mild stress (CUMS) with or without intervention with Cy. Our results showed that Cy significantly improved the depressive phenotypes in sucrose preference test, tail suspension test and forced swimming test. Meanwhile, increased SIRT3 expression, reduced ROS production and activated NF-kappa B signal were detected in the hippocampus of mice. NLRP3 inflammasome related proteins including NLRP3, ASC, Caspase-1, IL-1 beta, IL-18 and GSDMD-N were downregulated after Cy administration. Synaptic proteins including Synapsin-1 and PSD-95 and dendritic spine density were improved after Cy treatment. Moreover, the protective effects of Cy in CUMS mice were compromised when co-administrated with SIRT3 inhibitor 3-TYP. Taken together, these findings suggested that Cy has therapeutic potential for treating depression and that this antidepressant effect may be attributed to SIRT3 stimulated neuroplasticity enhancement by suppressing NLRP3 inflammasome.
    • Observer-driven texture analysis in CT imaging

      Kupinski, Matthew A.; Garrett, Zachary; Fan, Jiahua; Univ Arizona, Coll Opt Sci (SPIE-INT SOC OPTICAL ENGINEERING, 2020-03-16)
      We have implemented a technique for analyzing and characterizing the textures in medical images. This technique generates a list of characteristic textures and sorts them from most important to least important for the task of detecting a specific signal in the image. The effects of the human-visual system can be incorporated into this method through the use of an eye filter. The final set of sorted textures can be quickly utilized to analyze new sets of images and make comparison regarding performance on the same task. This analysis is based upon whether the new set of images contains textures that are similar or dissimilar to that of the original set of images. We present the method for analyzing and sorting textures based on how well signals can be distinguished. We also discuss the importance of the most "obscuring" textures that make signal-detection difficult. Results and comparisons of task performance are presented.
    • The Chandra Deep Wide-field Survey: A New Chandra Legacy Survey in the Boötes Field. I. X-Ray Point Source Catalog, Number Counts, and Multiwavelength Counterparts

      Masini, Alberto; Hickox, Ryan C.; Carroll, Christopher M.; Aird, James; Alexander, David M.; Assef, Roberto J.; Bower, Richard; Brodwin, Mark; Brown, Michael J. I.; Chatterjee, Suchetana; et al. (IOP PUBLISHING LTD, 2020-10-22)
      We present a new, ambitious survey performed with the Chandra X-ray Observatory of the 9.3 deg(2) Bootes field of the NOAO Deep Wide-Field Survey. The wide field probes a statistically representative volume of the universe at high redshift. The Chandra Deep Wide-field Survey exploits the excellent sensitivity and angular resolution of Chandra over a wide area, combining 281 observations spanning 15 yr, for a total exposure time of 3.4 Ms, and detects 6891 X-ray point sources down to limiting fluxes of 4.7 x 10(-16), 1.5 x 10(-16), and 9 x10(-16) erg cm(-2) s(-1) in the 0.5-7, 0.5-2, and 2-7 keV bands, respectively. The robustness and reliability of the detection strategy are validated through extensive, state-of-the-art simulations of the whole field. Accurate number counts, in good agreement with previous X-ray surveys, are derived thanks to the uniquely large number of point sources detected, which resolve 65.0% 12.8% of the cosmic X-ray background between 0.5 and 2 keV and 81.0% 11.5% between 2 and 7 keV. Exploiting the wealth of multiwavelength data available on the field, we assign redshifts to similar to 94% of the X-ray sources, estimate their obscuration, and derive absorption-corrected luminosities. We provide an electronic catalog containing all of the relevant quantities needed for future investigations.
    • Improving Information Extraction From Simulated Discharge Using Sensitivity‐Weighted Performance Criteria

      Guse, B.; Pfannerstill, M.; Fohrer, N.; Gupta, H.; Univ Arizona, Dept Hydrol & Atmospher Sci (AMER GEOPHYSICAL UNION, 2020-07-13)
      Due to seasonal or interannual variability, the relevance of hydrological processes and of the associated model parameters can vary significantly throughout the simulation period. To achieve accurately identified model parameters, temporal variations in parameter dominance should be taken into account. This is not achieved if performance criteria are applied to the entire model output time series. Even when using complementary performance criteria, it is often only possible to identify some of the model parameters precisely. We present an innovative approach to improve parameter identifiability that exploits the information available regarding temporal variations in parameter dominance. Using daily parameter sensitivity time series, we construct a set of sensitivity-weighted performance criteria, one for each parameter, whereby periods of higher dominance of a model parameter and its corresponding process are assigned higher weights in the calculation of the associated performance criterion. These criteria are used to impose constraints on parameter values. We demonstrate this approach by constraining 12 model parameters for three catchments and examine ensemble hydrological simulations generated using these constrained parameter sets. The sensitivity-weighted approach improves in particular the identifiability for parameters whose corresponding processes are dominant only for short periods of time or have strong seasonal patterns. This results overall in slight improvement of model performance for a set of 10 contrasting performance criteria. We conclude that the sensitivity-weighted approach improves the extraction of hydrologically relevant information from data, thereby resulting in improved parameter identifiability and better representation of model parameters.
    • Measuring Aquifer Specific Yields With Absolute Gravimetry: Result in the Choushui River Alluvial Fan and Mingchu Basin, Central Taiwan

      Chen, Kuan‐Hung; Hwang, Cheinway; Chang, Liang‐Cheng; Tsai, Jui‐Pin; Yeh, Tian‐Chyi Jim; Cheng, Ching‐Chung; Ke, Chien‐Chung; Feng, Wei; Univ Arizona, Dept Hydrol & Atmospher Sci (AMER GEOPHYSICAL UNION, 2020-06-08)
      Due to seasonal or interannual variability, the relevance of hydrological processes and of the associated model parameters can vary significantly throughout the simulation period. To achieve accurately identified model parameters, temporal variations in parameter dominance should be taken into account. This is not achieved if performance criteria are applied to the entire model output time series. Even when using complementary performance criteria, it is often only possible to identify some of the model parameters precisely. We present an innovative approach to improve parameter identifiability that exploits the information available regarding temporal variations in parameter dominance. Using daily parameter sensitivity time series, we construct a set of sensitivity-weighted performance criteria, one for each parameter, whereby periods of higher dominance of a model parameter and its corresponding process are assigned higher weights in the calculation of the associated performance criterion. These criteria are used to impose constraints on parameter values. We demonstrate this approach by constraining 12 model parameters for three catchments and examine ensemble hydrological simulations generated using these constrained parameter sets. The sensitivity-weighted approach improves in particular the identifiability for parameters whose corresponding processes are dominant only for short periods of time or have strong seasonal patterns. This results overall in slight improvement of model performance for a set of 10 contrasting performance criteria. We conclude that the sensitivity-weighted approach improves the extraction of hydrologically relevant information from data, thereby resulting in improved parameter identifiability and better representation of model parameters.
    • Sidecar Learning: a new e-learning platform for librarians

      Mery, Yvonne; Univ Arizona, Univ Arizona Lib (MEDICAL LIBRARY ASSOC, 2020-10)
      This article describes how two librarians at the University of Arizona created a new e-learning tool, Sidecar Learning, and implemented tutorials aimed at health sciences students and researchers. Librarians at the University of Arizona have used these interactive tutorials to reach thousands of students. Sidecar Learning was created to provide librarians with a scalable means of teaching thousands of students how to use complicated library databases.
    • Evaluation of drug information resources for interactions between therapeutic drugs and drugs of abuse

      Beckett, Robert D; Martin, Jennifer R; Stump, Curtis D; Dyer, Megan A; Univ Arizona, Hlth Sci Lib (MEDICAL LIBRARY ASSOC, 2020-10)
      A cross-sectional evaluation study was conducted focusing on seven resources: Clinical Pharmacology, Facts & Comparisons eAnswers, Lexicomp Online, Micromedex, Drug Interactions Analysis and Management, Drug Interaction Facts, and Stockley's Drug Interactions. A sample of clinically relevant interactions was developed through review of tertiary literature and resources, and input was solicited from subject matter experts. Entries from each resource for each interaction were evaluated for scope (i.e., whether there was an entry for the interaction); completeness (i.e., whether there was information addressing mechanism; clinical effects, severity, course of action, and level of certainty, described as a median rating on a 5-point scale); and consistency (i.e., whether the information in the resource was similar to the majority) among resources with an entry.
    • Measuring the prevalence of 60 health conditions in older Australians in residential aged care with electronic health records: a retrospective dynamic cohort study

      Lind, Kimberly E; Raban, Magdalena Z; Brett, Lindsey; Jorgensen, Mikaela L; Georgiou, Andrew; Westbrook, Johanna I; Univ Arizona, Mel & Enid Zuckerman Coll Publ Hlth, Dept Hlth Promot Sci (BMC, 2020-10-08)
      Background The number of older Australians using aged care services is increasing, yet there is an absence of reliable data on their health. Multimorbidity in this population has not been well described. A clear picture of the health status of people using aged care is essential for informing health practice and policy to support evidence-based, equitable, high-quality care. Our objective was to describe the health status of older Australians living in residential aged care facilities (RACFs) and develop a model for monitoring health conditions using data from electronic health record systems. Methods Using a dynamic retrospective cohort of 9436 RACF residents living in 68 RACFs in New South Wales and the Australian Capital Territory from 2014 to 2017, we developed an algorithm to identify residents' conditions using aged care funding assessments, medications administered, and clinical notes from their facility electronic health record (EHR). We generated age- and sex-specific prevalence estimates for 60 health conditions. Agreement between conditions recorded in aged care funding assessments and those documented in residents' EHRs was evaluated using Cohen's kappa. Cluster analysis was used to describe combinations of health conditions (multimorbidity) occurring among residents. Results Using all data sources, 93% of residents had some form of circulatory disease, with hypertension the most common (62%). Most residents (93%) had a mental or behavioural disorder, including dementia (58%) or depression (54%). For most conditions, EHR data identified approximately twice the number of people with the condition compared to aged care funding assessments. Agreement between data sources was highest for multiple sclerosis, Huntington's disease, and dementia. The cluster analysis identified seven groups with distinct combinations of health conditions and demographic characteristics and found that the most complex cluster represented a group of residents that had on average the longest lengths of stay in residential care. Conclusions The prevalence of many health conditions among RACF residents in Australia is underestimated in previous reports. Aged care EHR data have the potential to be used to better understand the complex health needs of this vulnerable population and can help fill the information gaps needed for population health surveillance and quality monitoring.