This open access archive contains publications from University of Arizona faculty, researchers and staff, primarily open-access versions of formally published journal articles. The collection includes published articles and final accepted manuscripts submitted by UA faculty under the UA Open Access Policy. The collection also includes books, book chapters, book reviews, presentations, data, and other scholarly materials submitters have chosen to make available in the repository.

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Recent Submissions

  • Excited-state effects in nucleon structure on the lattice using hybrid interpolators

    Green, Jeremy R.; Engelhardt, Michael; Hasan, Nesreen; Krieg, Stefan; Meinel, Stefan; Negele, John W.; Pochinsky, Andrew V.; Syritsyn, Sergey N.; Univ Arizona, Dept Phys (AMER PHYSICAL SOC, 2019-10-24)
    It would be very useful to find a way of reducing excited-state effects in lattice QCD calculations of nucleon structure that has a low computational cost. We explore the use of hybrid interpolators, which contain a nontrivial gluonic excitation, in a variational basis together with the standard interpolator with tuned smearing width. Using the clover discretization of the field strength tensor, a calculation using a fixed linear combination of standard and hybrid interpolators can be done using the same number of quark propagators as a standard calculation, making this a cost-effective option. We find that such an interpolator, optimized by solving a generalized eigenvalue problem, reduces excited-state contributions in two-point correlators. However, the effect in three-point correlators, which are needed for computing nucleon matrix elements, is mixed: for some matrix elements such as the tensor charge, excited-state effects are suppressed, whereas for others such as the axial charge, they are enhanced. The results illustrate that the variational method is not guaranteed to reduce the net contribution from excited states except in its asymptotic regime, and suggest that it may be important to use a large basis of interpolators capable of isolating all of the relevant low-lying states.
  • Islands of ice on Mars and Pluto

    Sori, Michael M.; Bapst, Jonathan; Becerra, Patricio; Byrne, Shane; Univ Arizona, Lunar & Planetary Lab (AMER GEOPHYSICAL UNION, 2019)
    Ice sheets, such as the polar layered deposits (PLDs) of Mars, are of great interest as records of past climate. Smaller outlier ice deposits near the north and south PLDs are likely more sensitive to climate changes and thus may hold information about more recent climate history. However, the southern outlier deposits have largely remained unmapped and unanalyzed. Here, we identify 31 deposits near, but separated from, Mars's south PLDs, all of which are located within impact craters >15 km in diameter. On the basis of morphology, radar analysis, physical similarity to portions of the PLD margin, and overall similarity to previously described deposits in Mars's north polar region, we conclude that these deposits are primarily composed of water ice. An additional 66 craters contain smaller depositional features, some of which may be remnant ice deposits. The 31 outlier ice deposits represent a previously unquantified inventory of water on Mars, with a total volume between 15,000 and 38,000 km(3). In addition, we identify five analogous outlier nitrogen ice deposits located within impact craters near Sputnik Planitia, the large nitrogen ice sheet on Pluto. Although important differences exist between Mars and Pluto, broad physical similarities between the two cases suggest that the topography and microclimates of impact craters cause them to be favorable locations for volatile accumulation and/or retention throughout the Solar System.
  • Thermal broadening of bottomonia: Lattice nonrelativistic QCD with extended operators

    Larsen, Rasmus; Meinel, Stefan; Mukherjee, Swagato; Petreczky, Peter; Univ Arizona, Dept Phys (AMER PHYSICAL SOC, 2019-10-21)
    We present lattice nonrelativistic QCD calculations of bottomonium correlation functions at temperatures T similar or equal to 150-350 MeV. The correlation functions were computed using extended bottomonium operators and on background gauge-field configurations for 2 + 1-flavor QCD having physical kaon and nearly physical pion masses. We analyzed these correlation functions based on simple theoretically motivated parametrizations of the corresponding spectral functions. The results of our analyses are compatible with significant in-medium thermal broadening of the ground state S- and P-wave bottomonia.
  • Selective Wander Join: Fast Progressive Visualizations for Data Joins

    Procopio, Marianne; Scheidegger, Carlos; Wu, Eugene; Chang, Remco; Univ Arizona, Dept Comp Sci (MDPI, 2019-03)
    Progressive visualization offers a great deal of promise for big data visualization; however, current progressive visualization systems do not allow for continuous interaction. What if users want to see more confident results on a subset of the visualization? This can happen when users are in exploratory analysis mode but want to ask some directed questions of the data as well. In a progressive visualization system, the online aggregation algorithm determines the database sampling rate and resulting convergence rate, not the user. In this paper, we extend a recent method in online aggregation, called Wander Join, that is optimized for queries that join tables, one of the most computationally expensive operations. This extension leverages importance sampling to enable user-driven sampling when data joins are in the query. We applied user interaction techniques that allow the user to view and adjust the convergence rate, providing more transparency and control over the online aggregation process. By leveraging importance sampling, our extension of Wander Join also allows for stratified sampling of groups when there is data distribution skew. We also improve the convergence rate of filtering queries, but with additional overhead costs not needed in the original Wander Join algorithm.
  • Property’s Relation to Human Rights

    Rose, Carol M.; Univ Arizona, Law Coll (ROUTLEDGE, TAYLOR & FRANCIS GROUP, 2019)
    How does property relate to human rights? Is property itself a human right, or contrariwise, an impediment to other human rights? or is the relationship something else? This chapter explores three areas in which property has raised controversies in modern human rights discussions: first, property’s connection to traditional groups’ claims to protect cultural identity; second, property’s role respecting human rights claims to social and economic rights; and finally, the role of property protection in deflecting other human rights abuses. This paper argues that in all these instances, property’s relation to human rights is best treated pragmatically, framing particular issues by inquiring about the ways in which property might or might not support other human rights claims—an inquiry that sometimes leads to unexpected results.
  • Presenteeism: Nurse perceptions and consequences

    Rainbow, Jessica G; Univ Arizona, Coll Nursing (WILEY, 2019-10-01)
    Aims To describe factors leading to and consequences of nurse presenteeism. Background Presenteeism is more prevalent among nurses than other occupational groups. Existing literatures focuses on prevalence and consequences of presenteeism for patients, health care organizations, and nurses. However, we lack understanding of nurse perceptions of factors leading to and consequences of presenteeism. Methods A total of 295 free responses to a cross-sectional survey were analysed using conventional content analysis. Results Nurses consider multiple factors in deciding how to respond when presentee. These include illness, staffing, availability of leave time, patients, financial constraints and guilt. Consequences of presenteeism identified were decreased mental acuity and attitude leading to lessened communication both in-person and in documentation, transmission of illness, and decline in unit culture, patient care, and nurse health and well-being. Conclusions Multiple factors lead to nurse presenteeism and there are negative consequences to nurses' health, work environment and patient care outcomes. Implications for Nursing Management This study leads to key discoveries to the reasons for and consequences of nurse presenteeism. Many of the factors leading to presenteeism can be addressed through culture and policy changes within organizations. The consequences to patient care outcomes and the work environment emphasize the importance of addressing presenteeism.
  • A record of flooding on the White River, Arkansas derived from tree-ring anatomical variability and vessel width

    Meko, Matthew D.; Therrell, Matthew D.; Univ Arizona, Lab Tree Ring Res (TAYLOR & FRANCIS LTD, 2019-10-13)
    Tree rings preserve important records of past flooding. We present the results of an examination of inter-annual tree-ring anatomical variability and vessel width in overcup oak (Quercus lyrata) and river flooding at a bottomland hardwood forest site near the confluence of the White and Mississippi Rivers. We developed two flood chronologies based on (1) visual identification of ?flood-ring? anatomical anomalies and (2) a simple method for quantitative measurements of earlywood vessel width (VW). Using visual flood rings, we have developed a response index (RI) chronology of floods from 1780?2013 and, using the VW measurements, we have developed a quantitative reconstruction of spring river levels from 1800?2013. Both the RI and VW chronologies are strongly related to spring river flooding and indicate that major floods such as those in 1805, 1826, 1844, 1852, 1858, occurred in the period prior to the systematic collection of stage data, and that the frequency of extreme events has greatly varied over the past two centuries. These chronologies provide important new information about Lower Mississippi River flooding in past centuries, and our simple method of measuring VW is a potentially useful new approach to the development of tree-ring records of flooding.
  • Assessment of YAP gene polymorphisms and arsenic interaction in Mexican women with breast cancer

    Michel-Ramirez, Gladis; Recio-Vega, Rogelio; Lantz, R Clark; Gandolfi, A Jay; Olivas-Calderon, Edgar; Chau, Binh T; Amistadi, Mary Kay; Univ Arizona, Dept Cellular & Mol Med; Univ Arizona, Southwest Environm Hlth Sci Ctr; Univ Arizona, Dept Pharmacol & Toxicol; et al. (WILEY, 2019-10-21)
    The identification of gene-environment interactions related to breast cancer reveals the biological and molecular mechanisms underlying the disease and allows the distinction of women at high risk from women at lower risk, which could decrease the morbimortality of this neoplasm. The current study evaluated the association between polymorphisms rs1820453 and rs11225161 of the Yes-associated protein (YAP) gene in women with breast cancer exposed to arsenic (As) through drinking water. In total, 182 women were assessed for the frequency of YAP rs1820453 and rs11225161 polymorphisms and As urinary levels. The results demonstrated a positive and significant association between breast cancer and smoking, type of drinking water, and levels of AsIII , AsV and inorganic As (iAs) but not the YAP gene polymorphisms evaluated. In conclusion, our data showed that the source of drinking water and AsV and iAs urinary levels increased the risk for breast cancer, but no interactions between YAP gene polymorphisms and As urinary levels were found.
  • Comparative pharmacokinetic study of PEGylated gemcitabine and gemcitabine in rats by LC-MS/MS coupled with pre-column derivatization and MS technique

    Yin, Lei; Ren, Tianming; Zhao, Shiying; Shi, Meiyun; Gu, Jingkai; Univ Arizona, Coll Pharm (ELSEVIER, 2020-01-01)
    Gemcitabine is a small molecular antitumor compound used to treat many types of solid tumors. The clinical application of gemcitabine is limited by its short biological half-life, rapid metabolism and poor tumor tissue targeting. The covalent attachment of polyethylene glycol to gemcitabine is a promising technique to overcome these limitations. After PEGylation, PEGylated gemcitabine could be metabolized into gemcitabine and its metabolites in vivo. Due to the scale effect of PEGylated gemcitabine, the DMPK process of the original drug is greatly changed. Therefore, understanding the pharmacokinetic behavior of PEGylated gemcitabine, gemcitabine and the metabolite dFdU in vivo is really important to clarify the antitumoral activity of these compounds. It would also guide the development of other PEGylated drugs. Due to the complex structure and diverse physiochemical property of PEG, direct quantification analysis of PEGylated gemcitabine presented many challenges in terms of assay sensitivity, selectivity, and robustness. In this article, a data-independent acquisition method, MSALL-based approach using electrospray ionization (ESI) coupled quadrupole time of flight mass spectrometry (MS), was utilized for the determination of PEGylated gemcitabine in rat plasma. The technique consists of a Q1 mass window through all the precursor ions, fragmenting and recording all product ions. PEGylated gemcitabine underwent dissociation in collision cell to generate a series of PEG related ions at m/z 89.0604, 133.0868, 177.1129 of 2, 3, 4 repeating ethylene oxide subunits and PEGylated gemcitabine related ions at m/z 112.0514. PEGylated gemcitabine was detected by the high resolution extracted ions based on the specific compound. For gemcitabine and dFdU, the study used derivatization of these high polarity compounds with dansyl chloride to improve their chromatographic retention. This paper describes comparative pharmacokinetic study of PEGylated gemcitabine and gemcitabine in rats by LC-MS/MS coupled with pre-column derivatization and MSALL technique. The results show that PEGylation could reduce the drug clearance of the conjugated compounds and increase the drug plasma half-life. After administration of PEGylated gemcitabine, the exposure of the free gemcitabine in vivo is lower than administration of gemcitabine, which means that PEGylated gemcitabine possesses lower toxicity compared with gemcitabine.
  • Automatic Detection of Everyday Social Behaviours and Environments from Verbatim Transcripts of Daily Conversations

    Yordanova, Kristina Y.; Demiray, Burcu; Mehl, Matthias R.; Martin, Mike; Univ Arizona, Dept Psychol (IEEE, 2019-03)
    Coding in social sciences is a process that involves the categorisation of qualitative or quantitative data in order to facilitate further analysis. Coding is usually a manual process that involves a lot of effort and time to produce codes with high validity and interrater reliability. Although automated methods for quantitative data analysis are largely used in social sciences, there are only a few attempts at automatically or semi-automatically coding the data collected in qualitative studies. To address this problem, in this work we propose an approach for automated coding of social behaviours and environments based on verbatim transcriptions of everyday conversations. To evaluate the approach, we analysed the transcripts from three datasets containing recordings of everyday conversations from: (1) young healthy adults (German transcriptions), (2) elderly healthy adults (German transcriptions), and (3) young healthy adults (English transcriptions). The results show that it is possible to automatically code the social behaviours and environments based on verbatim transcripts of the recorded conversations. This could reduce the time and effort researchers need to assign accurate codes to transcribed conversations.
  • Collective Action and Governance Activism

    Doidge, Craig; Dyck, Alexander; Mahmudi, Hamed; Virani, Aazam; Univ Arizona, Eller Coll Management (OXFORD UNIV PRESS, 2019-09)
    We examine how an investor collective action organization (ICAO) enhances activism by institutional investors. The ICAO initiated a new form of engagement-private meetings with independent directors to discuss governance proposals. Compared with a single investor acting alone, the ICAO has stronger incentives to engage in activism. Its dollar holdings and voting power are six times larger and predict direct access to the board and the firms it engages. Firms engaged by the ICAO are at least 58% more likely than non-engaged firms to adopt the ICAO's governance proposals that include adoption of majority voting, say-on-pay, and specific compensation policies. Engaged firms also increase CEO incentive pay. An event study around the announcement of the ICAO's formation shows a positive impact on value that increases in both dollar holdings and voting power. We conclude that institutional investors improve governance outcomes through collective action.
  • An Unexpected Romance: Reevaluating the Authorship of the Khosrow-nāma

    O'Malley, Austin; Middle East and North African Studies; Univ Arizona, Sch Middle Eastern & North African Studies (Middle East Medievalists, 2019)
    This article examines the authorship of the Khosrow-nāma, a Perso-Hellenic romance traditionally attributed to ʿAṭṭār. Forty years ago, Shafiʿi-Kadkani laid out a complex argument against ʿAṭṭār’s authorship. He claimed that the attribution was a result of a later forgery, basing his argument on internal chronological evidence, religious and stylistic markers, and the manuscript tradition. The present article systematically evaluates this argument, showing it to be less persuasive than it first appears. First, I introduce new manuscript evidence to demonstrate that the poem was circulating under ʿAṭṭār’s name already before the time of the alleged forgery. I then reassess the internal evidence to show that the Khosrow-nāma could, in fact, fit into a plausible chronology of ʿAṭṭār’s oeuvre. Next, I critique the stylistic and religious arguments against ʿAṭṭār’s authorship, arguing that the romance does not deviate from ʿAṭṭār’s undisputed works nearly as much as is often supposed. I conclude by suggesting that the available data are explained more easily by accepting ʿAṭṭār’s authorship than by adopting the theory of a later forgery.
  • Sediment Respiration Pulses in Intermittent Rivers and Ephemeral Streams

    Bogan, M. T.; Cid, N.; Univ Arizona, Sch Nat Resources & Environm (American Geophysical Union (AGU), 2019-10-16)
    Intermittent rivers and ephemeral streams (IRES) may represent over half the global stream network, but their contribution to respiration and carbon dioxide (CO2) emissions is largely undetermined. In particular, little is known about the variability and drivers of respiration in IRES sediments upon rewetting, which could result in large pulses of CO2. We present a global study examining sediments from 200 dry IRES reaches spanning multiple biomes. Results from standardized assays show that mean respiration increased 32-fold to 66-fold upon sediment rewetting. Structural equation modeling indicates that this response was driven by sediment texture and organic matter quantity and quality, which, in turn, were influenced by climate, land use, and riparian plant cover. Our estimates suggest that respiration pulses resulting from rewetting of IRES sediments could contribute significantly to annual CO2 emissions from the global stream network, with a single respiration pulse potentially increasing emission by 0.2-0.7%. As the spatial and temporal extent of IRES increases globally, our results highlight the importance of recognizing the influence of wetting-drying cycles on respiration and CO2 emissions in stream networks.
  • Assessing Gauge Undercatch Correction in Arctic Basins in Light of GRACE Observations

    Behrangi, Ali; Singh, Alka; Song, Yang; Panahi, Milad; Univ Arizona, Dept Hydrol & Atmospher Sci; Univ Arizona, Dept Geosci (AMER GEOPHYSICAL UNION, 2019-10-09)
    Precipitation measurements at gauges are often considered as reference truth for evaluation of satellite precipitation products. However, gauges may contain large errors. A major source of gauge‐measurement error is snowfall undercatch in high latitudes. We show that the two popular correction factors (CFs) used in the Global Precipitation Climatology Centre monitoring and the Global Precipitation Climatology Project products are different by more than 50%. The CFs can be as large as 3; thus, the choice of CF introduces large uncertainties. Here, in light of observation of storage change from the Gravity Recovery and Climate Experiment (GRACE) and by using the mass conservation principle, we assess the two popular CFs over six Arctic basins. By investigating monthly time series and multiyear precipitation rates over the studied basins using GRACE‐based analysis, the CF based on Fuchs dynamic correction model used in Global Precipitation Climatology Centre monitoring is preferred.
  • Velocity Field Estimation on Density‐Driven Solute Transport With a Convolutional Neural Network

    Kreyenberg, Philipp J.; Bauser, Hannes H.; Roth, Kurt; Univ Arizona, Biosphere 2 (AMER GEOPHYSICAL UNION, 2019-08-01)
    Recent advances in machine learning open new opportunities to gain deeper insight into hydrological systems, where some relevant system quantities remain difficult to measure. We use deep learning methods trained on numerical simulations of the physical processes to explore the possibilities of closing the information gap of missing system quantities. As an illustrative example we study the estimation of velocity fields in numerical and laboratory experiments of density‐driven solute transport. Using high‐resolution observations of the solute concentration distribution, we demonstrate the capability of the method to structurally incorporate the representation of the physical processes. Velocity field estimation for synthetic data for both variable and uniform concentration boundary conditions showed equal results. This capability is remarkable because only the latter was employed for training the network. Applying the method to measured concentration distributions of density‐driven solute transport in a Hele‐Shaw cell makes the velocity field assessable in the experiment. This assessability of the velocity field even holds for regions with negligible solute concentration between the density fingers, where the velocity field is otherwise inaccessible.
  • Seasonal and Topographic Variations in Ecohydrological Separation Within a Small, Temperate, Snow‐Influenced Catchment

    Knighton, James; Souter‐Kline, Valessa; Volkman, Till; Troch, Peter A.; Kim, Minseok; Harman, Ciaran; Morris, Chelsea; Buchanan, Brian; Walter, M. Todd; Univ Arizona, Biosphere 2 (AMER GEOPHYSICAL UNION, 2019-08-02)
    The hypothesis of ecohydrological separation (ES) proposes that the water contained in surface soils is not uniformly extracted by root water uptake nor uniformly displaced by infiltration. Rather vegetation selectively removes water held under tension, and water infiltrating wet soil will bypass much of the water‐filled pore space. Methodological differences across previous studies have contributed to disagreement concerning the prevalence of ES. We measured stable isotopes of O and H in precipitation, snowpack, canopy throughfall, and stream water over a period of 18 months in a temperate catchment. At six locations across a wetness gradient, we sampled bulk soil water isotopes weekly and xylem water of Eastern hemlock and American beech stems seasonally. We used these observations in a soil column model including StorAge Selection functions to estimate the isotopic composition and ages of groundwater recharge and ET. Our findings suggest ES may exist with spatial and temporal heterogeneity. Root water uptake ages possibly vary between Eastern hemlock and American beech, suggesting functional strategies for water uptake may control the presence of ES. Newly infiltrated water bypassing the shallow soil was the most likely explanation for bulk soil isotopic measurements made at upslope locations during the winter and summer seasons, whereas rapid displacement of stored soil water by infiltrated waters was the most likely during the spring and fall seasons. Future research incorporating high temporal frequency soil and plant xylem water isotopic measurements applied to StorAge Selection functions may provide a useful framework for understanding rooting zone isotope dynamics.
  • Energy development reveals blind spots for ecosystem conservation in the Amazon Basin

    Anderson, Elizabeth P; Osborne, Tracey; Maldonado‐Ocampo, Javier A; Mills‐Novoa, Megan; Castello, Leandro; Montoya, Mariana; Encalada, Andrea C; Jenkins, Clinton N; Univ Arizona, Sch Geog & Dev (WILEY, 2019-10-02)
    Energy development – as manifested by the proliferation of hydroelectric dams and increased oil and gas exploration – is a driver of change in Amazonian ecosystems. However, prevailing approaches to Amazonian ecosystem conservation that focus on terrestrial protected areas and Indigenous territories do not offer sufficient insurance against the risks associated with energy development. Here, we explore three related areas of concern: the exclusion of subsurface rights on Indigenous lands; the absence of frameworks for freshwater ecosystem conservation; and downgrading, downsizing, degazettement (loss of protection), and reclassification of protected areas. We consider these issues from the perspectives of multiple countries across the Amazon Basin, and link them directly to energy development. Finally, we offer suggestions for addressing the challenges of energy development for Amazon ecosystem conservation through existing policies, new approaches, and international collaboration.
  • Kinematic focus point method for particle mass measurements in missing energy events

    Kim, Doojin; Matchev, Konstantin T.; Shyamsundar, Prasanth; Univ Arizona, Dept Phys (SPRINGER, 2019-10-14)
    We investigate the solvability of the event kinematics in missing energy events at hadron colliders, as a function of the particle mass ansatz. To be specific, we reconstruct the neutrino momenta in dilepton tt¯-like events, without assuming any prior knowledge of the mass spectrum. We identify a class of events, which we call extreme events, with the property that the kinematic boundary of their allowed region in mass parameter space passes through the true mass point. We develop techniques for recognizing extreme events in the data and demonstrate that they are abundant in a realistic data sample, due to expected singularities in phase space. We propose a new method for mass measurement whereby we obtain the true values of the mass parameters as the focus point of the kinematic boundaries for all events in the data sample. Since the masses are determined from a relatively sharp peak structure (the density of kinematic boundary curves), the method avoids some of the systematic errors associated with other techniques. We show that this new approach is complementary to previously considered methods in the literature where one studies the solvability of the kinematic constraints throughout the mass parameter space. In particular, we identify a problematic direction in mass space of nearly 100% solvability, and then show that the focus point method is effective in lifting the degeneracy.
  • The effects of hydroxypropyl-beta-cyclodextrin on olfaction in mouse models of Niemann-Pick C1 Disease

    Erickson, Robert; Univ Arizona, Sch Med, Dept Pediat (SPRINGER HEIDELBERG, 2019-08)
    The Npc1(nih/nih)-null model and the Npc1(nmf164/nmf164) hypomorph models of Niemann-Pick C1 (NPC1) disease show defects in olfaction. We have tested the effects of the life-prolonging treatment hydroxypropyl-beta-cyclodextrin (HPBCD) on olfaction and neural stem cell numbers when delivered either systemically or by nasal inhalation. Using the paradigm of finding a hidden cube of food after overnight food deprivation, Npc1(nih/nih) homozygous mice showed a highly significant delay in finding the food compared with wild-type mice. Npc1(nmf164/nmf164) homozygous mice showed an early loss of olfaction which was mildly corrected by somatic delivery of HPBCD which also increased the number of neural stem cells in the mutant but did not change the number in wild-type mice. In contrast, nasal delivery of this drug, at 1/5 the dosage used for somatic delivery, to Npc1(nmf164/nmf164) mutant mice delayed loss of olfaction but the control of nasal delivered saline did so as well. The nasal delivery of HPBCD to wild-type mice caused loss of olfaction but nasal delivery of saline did not. Neural stem cell counts were not improved by nasal therapy with HPBCD. We credit the delay in olfaction found with the treatment, a delay which was also found for time of death, to a large amount of stimulation the mice received with handling during the nasal delivery.
  • Can emergency physicians perform extended compression ultrasound for the diagnosis of lower extremity deep vein thrombosis

    Situ-LaCasse, Elaine; Guirguis, Helpees; Friedman, Lucas; Patanwala, Asad E; Cohen, Seth E; Adhikari, Srikar; Univ Arizona, Dept Emergency Med, Coll Med; Univ Arizona, Banner Univ Med Ctr; Univ Arizona, Coll Med; Univ Arizona, Coll Pharm (ZHEJIANG UNIV SCH MEDICINE, 2019-08)
    Background: Current point-of-care ultrasound protocols in the evaluation of lower extremity deep vein thrombosis (DVT) can miss isolated femoral vein clots. Extended compression ultrasound (ECUS) includes evaluation of the femoral vein from the femoral vein/deep femoral vein bifurcation to the adductor canal. Our objective is to determine if emergency physicians (EPs) can learn ECUS for lower extremity DVT evaluation after a focused training session. Methods: Prospective study at an urban academic center. Participants with varied ultrasound experience received instruction in ECUS prior to evaluation. Two live models with varied levels of difficult sonographic anatomy were intentionally chosen for the evaluation. Each participant scanned both models. Pre- and post-study surveys were completed. Results: A total of 96 ultrasound examinations were performed by 48 participants (11 attendings and 37 residents). Participants' assessment scores averaged 95.8% (95% CI 93.3%-98.3%) on the easier anatomy live model and averaged 92.3% (95% CI 88.4%-96.2%) on the difficult anatomy model. There were no statistically significant differences between attendings and residents. On the model with easier anatomy, all but 1 participant identified and compressed the proximal femoral vein successfully, and all participants identified and compressed the mid and distal femoral vein. With the difficult anatomy, 97.9% (95% CI 93.8%-102%) identified and compressed the proximal femoral vein, whereas 93.8% (95% CI 86.9%-100.6%) identified and compressed the mid femoral vein, and 91.7% (95% CI 83.9%-99.5%) identified and compressed the distal femoral vein. Conclusion: EPs at our institution were able to perform ECUS with good reproducibility after a focused training session.

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