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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

  • The apparent (gravitational) horizon in cosmology

    Melia, Fulvio; Univ Arizona, Dept Phys, Appl Math Program; Univ Arizona, Dept Astron (AMER ASSOC PHYSICS TEACHERS, 2018-08)
    In general relativity, a gravitational horizon (more commonly known as the "apparent horizon") an imaginary surface beyond which all null geodesics recede from the observer. The Universe has an apparent (gravitational) horizon, but unlike its counterpart in the Schwarzschild and Kerr metrics, it is not static. It may eventually turn into an event horizon-an asymptotically defined membrane that forever separates causally connected events from those that are not-depending on the equation of state of the cosmic fluid. In this paper, we examine how and why an apparent (gravitational) horizon is manifested in the Friedmann-Robertson-Walker metric, and why it is becoming so pivotal to our correct interpretation of the cosmological data. We discuss its observational signature and demonstrate how it alone defines the proper size of our visible Universe. In so doing, we affirm its physical reality and its impact on cosmological models. (C) 2018 American Association of Physics Teachers.
  • Clinical learning experiences of nursing students using an innovative clinical partnership model: A non-randomized controlled trial

    Chan, Aileen W.K.; Tang, Fiona W.K.; Choi, Kai Chow; Liu, Ting; Taylor-Piliae, Ruth E.; Univ Arizona, Coll Nursing (CHURCHILL LIVINGSTONE, 2018-09)
    Background: Clinical practicum is a major learning component for pre-registration nursing students. Various clinical practicum models have been used to facilitate students' clinical learning experiences, employing both university-based and hospital-based clinical teachers. Considering the strengths and limitations of these clinical practicum models, along with nursing workforce shortages, we developed and tested an innovative clinical partnership model (CPM) in Hong Kong. Objective: To evaluate an innovative CPM among nursing students actual and preferred clinical learning environment, compared with a conventional facilitation model (CFM). Design: A non-randomized controlled trial examining students' clinical experiences, comparing the CPM (supervised by hospital clinical teacher) with the CFM (supervised by university clinical teacher). Setting One university in Hong Kong. Participants: Pre-registration nursing students (N = 331), including bachelor of nursing (n = 246 year three-BN) and masters-entry nursing (n = 85 year one-MNSP). Methods: Students were assigned to either the CPM (n = 48 BN plus n = 85 MNSP students) or the CFM (n = 198 BN students) for their clinical practice experiences in an acute medical-surgical ward. Clinical teachers supervised between 6 and 8 students at a time, during these clinical practicums (duration = 4-6 weeks). At the end of the clinical practicum, students were invited to complete the Clinical Learning Environment Inventory (CLEI). Analysis of covariance was used to compare groups; adjusted for age, gender and prior work experience. Results: A total of 259 students (mean age = 22 years, 76% female, 81% prior work experience) completed the CLEI (78% response rate). Students had higher scores on preferred versus actual experiences, in all domains of the CLEI. CPM student experiences indicated a higher preferred task orientation (p = 0.004), while CFM student experiences indicated a higher actual (p < 0.001) and preferred individualization (p = 0.005). No significant differences were noted in the other domains. Conclusions: The CPM draws on the strengths of existing clinical learning models and provides complementary methods to facilitate clinical learning for pre-registration nursing students. Additional studies examining this CPM with longer duration of clinical practicum are recommended.
  • Isolation and characterization of 21 novel microsatellite loci in sailfish Istiophorus platypterus Shaw 1792 from a shotgun genomic library

    Rubio-Castro, G. G.; Munguia-Vega, A.; Quinonez-Velazquez, C.; Garcia-Rodriguez, F. J.; Univ Arizona, Sch Nat Resources & Environm (WILEY, 2018-08)
  • Speech Perception in Noise and Listening Effort of Older Adults With Nonlinear Frequency Compression Hearing Aids

    Shehorn, James; Marrone, Nicole; Muller, Thomas; Univ Arizona, Dept Speech Language & Hearing Sci (LIPPINCOTT WILLIAMS & WILKINS, 2018-03)
    Objectives: The purpose of this laboratory-based study was to compare the efficacy of two hearing aid fittings with and without nonlinear frequency compression, implemented within commercially available hearing aids. Previous research regarding the utility of nonlinear frequency compression has revealed conflicting results for speech recognition, marked by high individual variability. Individual differences in auditory function and cognitive abilities, specifically hearing loss slope and working memory, may contribute to aided performance. The first aim of the study was to determine the effect of nonlinear frequency compression on aided speech recognition in noise and listening effort using a dual-task test paradigm. The hypothesis, based on the Ease of Language Understanding model, was that nonlinear frequency compression would improve speech recognition in noise and decrease listening effort. The second aim of the study was to determine if listener variables of hearing loss slope, working memory capacity, and age would predict performance with nonlinear frequency compression. Design: A total of 17 adults (age, 57-85 years) with symmetrical sensorineural hearing loss were tested in the sound field using hearing aids fit to target (NAL-NL2). Participants were recruited with a range of hearing loss severities and slopes. A within-subjects, single-blinded design was used to compare performance with and without nonlinear frequency compression. Speech recognition in noise and listening effort were measured by adapting the Revised Speech in Noise Test into a dual-task paradigm. Participants were required trial-by-trial to repeat the last word of each sentence presented in speech babble and then recall the sentence-ending words after every block of six sentences. Half of the sentences were rich in context for the recognition of the final word of each sentence, and half were neutral in context. Extrinsic factors of sentence context and nonlinear frequency compression were manipulated, and intrinsic factors of hearing loss slope, working memory capacity, and age were measured to determine which participant factors were associated with benefit from nonlinear frequency compression. Results: On average, speech recognition in noise performance significantly improved with the use of nonlinear frequency compression. Individuals with steeply sloping hearing loss received more recognition benefit. Recall performance also significantly improved at the group level, with nonlinear frequency compression revealing reduced listening effort. The older participants within the study cohort received less recall benefit than the younger participants. The benefits of nonlinear frequency compression for speech recognition and listening effort did not correlate with each other, suggesting separable sources of benefit for these outcome measures. Conclusions: Improvements of speech recognition in noise and reduced listening effort indicate that adult hearing aid users can receive benefit from nonlinear frequency compression in a noisy environment, with the amount of benefit varying across individuals and across outcome measures. Evidence supports individualized selection of nonlinear frequency compression, with results suggesting benefits in speech recognition for individuals with steeply sloping hearing losses and in listening effort for younger individuals. Future research is indicated with a larger data set on the dual-task paradigm as a potential cognitive outcome measure.
  • OCEANUS: A high science return Uranus orbiter with a low-cost instrument suite

    Elder, C.M.; Bramson, A.M.; Blum, L.W.; Chilton, H.T.; Chopra, A.; Chu, C.; Das, A.; Davis, A.B.; Delgado, A.; Fulton, J.; Jozwiak, L.M.; Khayat, A.; Landis, M.E.; Molaro, J.L.; Slipski, M.; Valencia, S.; Watkins, J.; Young, C.L.; Budney, C.J.; Mitchell, K.L.; Univ Arizona, Lunar & Planetary Lab (PERGAMON-ELSEVIER SCIENCE LTD, 2018-07)
    Ice-giant-sized planets are the most common type of observed exoplanet, yet the two ice giants in our own solar system (Uranus and Neptune) are the least explored class of planet, having only been observed through ground based observations and a single flyby each by Voyager 2 approximately 30 years ago. These single flybys were unable to characterize the spatial and temporal variability in ice giant magnetospheres, some of the most odd and intriguing magnetospheres in the solar system. They also offered only limited constraints on the internal structure of ice giants; understanding the internal structure of a planet is important for understanding its formation and evolution. The most recent planetary science Decadal Survey by the U.S. National Academy of Sciences, "Vision and Voyages for Planetary Science in the Decade 2013-2022," identified the ice giant Uranus as the third highest priority for a Flagship mission in the decade 2013-2022. However, in the event that NASA or another space agency is unable to fly a Flagship-class mission to an ice giant in the next decade, this paper presents a mission concept for a focused, lower cost Uranus orbiter called OCEANUS (Origins and Composition of the Exoplanet Analog Uranus System). OCEANUS would increase our understanding of the interior structure of Uranus, its magnetosphere, and how its magnetic field is generated. These goals could be achieved with just a magnetometer and the spacecraft's radio system. This study shows that several of the objectives outlined by the Decadal Survey, including one of the two identified as highest priority, are within reach for a New-Frontiers-class mission.
  • HMGB1 binds to the KRAS promoter G-quadruplex: a new player in oncogene transcriptional regulation?

    Amato, Jussara; Madanayake, Thushara W.; Iaccarino, Nunzia; Novellino, Ettore; Randazzo, Antonio; Hurley, Laurence H.; Pagano, Bruno; Univ Arizona, Coll Pharm (ROYAL SOC CHEMISTRY, 2018-09-04)
    This communication reports on a possible distinct role of HMGB1 protein. Biophysical studies revealed that HMGB1 binds and stabilizes the G-quadruplex of the KRAS promoter element that is responsible for most of the transcriptional activity. Biological data showed that inhibition of HMGB1 increases KRAS expression. These results suggest that HMGB1 could play a role in the gene transcriptional regulation via the functional recognition of the G-quadruplex.
  • Unprecedented S-34-enrichment of pyrite formed following microbial sulfate reduction in fractured crystalline rocks

    Drake, Henrik; Whitehouse, Martin J.; Heim, Christine; Reiners, Peter W.; Tillberg, Mikael; Hogmalm, K. Johan; Dopson, Mark; Broman, Curt; Åström, Mats E.; Univ Arizona, Dept Geosci (WILEY, 2018-09)
    In the deep biosphere, microbial sulfate reduction (MSR) is exploited for energy. Here, we show that, in fractured continental crystalline bedrock in three areas in Sweden, this process produced sulfide that reacted with iron to form pyrite extremely enriched in S-34 relative to S-32. As documented by secondary ion mass spectrometry (SIMS) microanalyses, the S-34(pyrite) values are up to +132 parts per thousand V-CDT and with a total range of 186 parts per thousand. The lightest S-34(pyrite) values (-54 parts per thousand) suggest very large fractionation during MSR from an initial sulfate with S-34 values (S-34(sulfate,0)) of +14 to +28 parts per thousand. Fractionation of this magnitude requires a slow MSR rate, a feature we attribute to nutrient and electron donor shortage as well as initial sulfate abundance. The superheavy S-34(pyrite) values were produced by Rayleigh fractionation effects in a diminishing sulfate pool. Large volumes of pyrite with superheavy values (+120 +/- 15 parts per thousand) within single fracture intercepts in the boreholes, associated heavy average values up to +75 parts per thousand and heavy minimum S-34(pyrite) values, suggest isolation of significant amounts of isotopically light sulfide in other parts of the fracture system. Large fracture-specific S-34(pyrite) variability and overall average S-34(pyrite) values (+11 to +16 parts per thousand) lower than the anticipated S-34(sulfate,0) support this hypothesis. The superheavy pyrite found locally in the borehole intercepts thus represents a late stage in a much larger fracture system undergoing Rayleigh fractionation. Microscale Rb-Sr dating and U/Th-He dating of cogenetic minerals reveal that most pyrite formed in the early Paleozoic era, but crystal overgrowths may be significantly younger. The C-13 values in cogenetic calcite suggest that the superheavy S-34(pyrite) values are related to organotrophic MSR, in contrast to findings from marine sediments where superheavy pyrite has been proposed to be linked to anaerobic oxidation of methane. The findings provide new insights into MSR-related S-isotope systematics, particularly regarding formation of large fractions of S-34-rich pyrite.
  • Half-Watt Tm3+-Doped Fluoride Fiber Laser at 785 nm

    Mollaee, Masoud; Zhu, Xiushan; Zong, Jie; Wiersma, Kort; Chavez-Pirson, Arturo; Norwood, R. A.; Peyghambarian, N.; Univ Arizona, Coll Opt Sci (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2018-09-01)
    All-fiber single-transverse-mode laser oscillators operating at 785 nm were demonstrated by splicing a 0.1 mol% Tm3+-doped fluoride fiber with a core diameter of 4 mu m and a numerical aperture of 0.07 to a pair of silica fiber Bragg gratings. About 500 mW of continuous-wave single transverse mode laser output at 784.5 nm with a 3-dB spectral bandwidth of 0.2 nm was obtained by upconversion pumping a 3-m-long gain fiber at 1125 nm. Our experiments show that the ground-state absorption of Tm3(+ )at 785 nm is the origin of low efficiency in previous reports. The efficiency of this all-fiber laser can be improved by using a gain fiber with an optimized overlap between the laser, the pump, and the fiber core, and employing new pumping schemes that deplete the ground state sufficiently.
  • Does policy uncertainty affect mergers and acquisitions?

    Bonaime, Alice; Gulen, Huseyin; Ion, Mihai; Univ Arizona, Eller Coll Management (ELSEVIER SCIENCE SA, 2018-09)
    Political and regulatory uncertainty is strongly negatively associated with merger and acquisition activity at the macro and firm levels. The strongest effects are for uncertainty regarding taxes, government spending, monetary and fiscal policies, and regulation. Consistent with a real options channel, the effect is exacerbated for less reversible deals and for firms whose product demand or stock returns exhibit greater sensitivity to policy uncertainty, but attenuated for deals that cannot be delayed due to competition and for deals that hedge firm-level risk. Contractual mechanisms (deal premiums, termination fees, MAC clauses) unanimously point to policy uncertainty increasing the target's negotiating power. Published by Elsevier B.V.
  • Root-letter priming in Maltese visual word recognition

    Univ Arizona, Dept Linguist (JOHN BENJAMINS PUBLISHING CO, 2018)
    We report on a visual masked priming experiment designed to explore the role of morphology in Maltese visual word recognition. In a lexical decision task, subjects were faster to judge Maltese words of Semitic origin that were primed by triconsonantal letter-strings corresponding to their root-morphemes. In contrast, they were no faster to judge Maltese words of non-Semitic origin that were primed by an equivalent, but non-morphemic, set of three consonant letters, suggesting that morphological overlap, rather than simple form overlap, drives this facilitatory effect. Maltese is unique among the Semitic languages for its orthography: Maltese alone uses the Latin alphabet and requires that all vowels are written, making such triconsonantal strings illegal non-words to which Maltese readers are never exposed, as opposed to other Semitic languages such as Hebrew in which triconsonantal strings often correspond to real words. Under a decomposition-based account of morphological processing, we interpret these results as suggesting that across reading experience Maltese readers have abstracted out and stored root-morphemes for Semitic-origin words lexically, such that these morphemic representations can be activated by exposure to root-letters in isolation and thus prime morphological derivatives.
  • Pilot Randomized Controlled Trial to Reduce Readmission for Heart Failure Using Novel Tablet and Nurse Practitioner Education

    Breathett, Khadijah; Maffett, Scott; Foraker, Randi E.; Sturdivant, Rod; Moon, Kristina; Hasan, Ayesha; Franco, Veronica; Smith, Sakima; Lampert, Brent C.; Emani, Sitaramesh; Haas, Garrie; Kahwash, Rami; Hershberger, Ray E.; Binkley, Philip F.; Helmkamp, Laura; Colborn, Kathryn; Peterson, Pamela N.; Sweitzer, Nancy; Abraham, William T.; Univ Arizona, Sarver Heart Ctr, Div Cardiovasc Med (ELSEVIER SCIENCE INC, 2018-08)
    BACKGROUND: Heart failure education programs are not standardized. The best form of education is unclear. We evaluated whether addition of a novel tablet application to nurse practitioner (NP) education was superior to NP education alone in reducing 30-day readmission after heart failure hospitalization. METHODS: From February 2015-March 2016. patients admitted to a quaternary academic center with primary diagnosis of heart failure were randomized to 1) treatment - NP education plus tablet application (interactive conditional logic program that flags patient questions to medical staff), or 2) control - NP education. The primary outcome was reduction in 30-day readmission rate. Secondary outcomes included satisfaction and education assessed via survey. RESULTS: Randomization included 60 patients to treatment and 66 to control. A total of 13 patients withdrew prior to intervention (treatment n = 4, control n = 1) or were lost to follow-up (treatment n = 3, control n = 5). The 30-day readmission rate trended lower for treatment compared with control, but results were not statistically significant (13.2% [7/53]. 26.7% [16/60]. respectively, P = .08). Similarly, satisfaction trended higher with treatment than control (P = .08). Treatment patients rated explanations from their physicians higher than control (Always: 83.7%. 55.8%, respectively, P = .01). CONCLUSIONS: NP education plus tablet use was not associated with significantly lower 30-day readmission rates in comparison with NP alone, but a positive trend was seen. Patient satisfaction trended higher and heart failure explanations were better with NP education plus tablet. A larger study is needed to determine if NP education plus tablet reduces readmission rates following heart failure admission. (C) 2018 Elsevier Inc. All rights reserved.
  • The dynamics of stress and fatigue across menopause

    Taylor-Swanson, Lisa; Wong, Alexander E.; Pincus, David; Butner, Jonathan E.; Hahn-Holbrook, Jennifer; Koithan, Mary; Wann, Kathryn; Woods, Nancy F.; Univ Arizona, Coll Nursing (LIPPINCOTT WILLIAMS & WILKINS, 2018-04)
    Objective: The objective of this study was to evaluate the regulatory dynamics between stress and fatigue experienced by women during the menopausal transition (MT) and early postmenopause (EPM). Fatigue and perceived stress are commonly experienced by women during the MT and EPM. We sought to discover relationships between these symptoms and to employ these symptoms as possible markers for resilience. Methods: Participants were drawn from the longitudinal Seattle Midlife Women's Health Study. Eligible women completed questionnaires on 60+ occasions (annual health reports and monthly health diaries) (n = 56 women). The total number of observations across the sample was 4,224. STRAW+10 criteria were used to stage women in either in late reproductive, early or late transition, or EPM stage. Change values were generated for fatigue and stress and analyzed with a multilevel structural equation model; slopes indicate how quickly a person returns to homeostasis after a perturbation. Coupling of stress and fatigue was modeled to evaluate resilience, the notion of maintaining stability during change. Results: Eligible women were on average 35 years old (SD = 4.71), well educated, employed, married or partnered, and white. Fit indices suggested the model depicts the relationships of stress and fatigue (chi(2) (9 df) = 7.638, P = 0.57, correction factor = 4.9244; root mean square error of approximation 90% CI = 0.000 <= 0.000 <= 0.032; comparative fit index = 1.00). A loss in model fit across stages suggests that the four stages differed in their dynamics (chi(2) Delta(12 df) = 21.181, P = .048). All stages showed fixed-point attractor dynamics: fatigue became less stable over time; stress generally became more stable over time. Coupling relationships of stress on fatigue show evidence for shifts in regulatory relationships with one another across the MT. Conclusions: Results are suggestive of general dysregulation via disruptions to coupling relationships of stress and fatigue across the MT. Findings support a holistic approach to understanding symptoms and supporting women during the MT.
  • Approaches to community consultation in exception from informed consent: Analysis of scope, efficiency, and cost at two centers

    Eubank, Louis; Lee, Kwan S.; Seder, David B.; Strout, Tania; Darrow, Matthew; MacDonald, Catherine; May, Teresa; Riker, Richard R.; Kern, Karl B.; Univ Arizona, Div Cardiol, Sarver Heart Ctr (ELSEVIER IRELAND LTD, 2018-09)
    Objectives: Community consultation (CC) is fundamental to the Exception from Informed Consent (EFIC) process for emergency research, designed to inform and receive feedback from the target study population about potential risks and benefits. To better understand the effectiveness of different techniques for CC, we evaluated EFIC processes at two centers participating in a trial of early cardiac catheterization following out-of-hospital cardiac arrest. Methods: We studied the Institutional Review Board-approved CC activities at Maine Medical Center (MMC) and University of Arizona (AZ) in support of NCT02387398. In Maine, the public was consulted by survey at a professional basketball game and in the emergency department waiting room (in-person group), by multimedia direction to an online website (online group), and by mail (mailing group). Arizona respondents were either approached at a county fair (in-person group) or were directed to an online survey (online group) via social media advertising. Results: Among 2185 survey respondents, approval rates were high for community involvement and personal participation without individual consent. Community consultation using in-person, online, and mailed surveys offered slightly different approval rates, and the rate of responses by modality differed by age and education level but not ethnicity. Print advertising was the least cost effective at $ 442 per completed survey. Conclusions: Canvassing at public events was the most efficient mode of performing CC, with approval rates similar to mailings, online surveys, and canvassing in other locations. Print advertisements in local papers had a low yield and cost more than other approaches.
  • Quit Outcomes and Program Utilization by Mode of Entry Among Clients Enrolling in a Quitline

    Nair, Uma S.; Reikowsky, Ryan C.; Wertheim, Betsy C.; Thomson, Cynthia A.; Gordon, Judith S.; Univ Arizona, Mel & Enid Zuckerman Coll Publ Hlth; Univ Arizona, Canc Ctr; Univ Arizona, Coll Nursing (SAGE PUBLICATIONS INC, 2018-09)
    Purpose: To investigate how mode of entry into a quitline influences program utilization and quit outcomes among clients seeking cessation services. Design: This is a retrospective analysis of clients receiving quitline services from January 2011 to June 2016. Setting: The study was conducted at the Arizona Smokers' Helpline. Participants: Enrolled clients completed a 7-month follow-up (N = 18 650). Measures: The independent variable was referral mode of entry (ie, proactive, passive, and self-referral). Outcome variables included tobacco cessation medication use, number of coaching sessions completed, and 30-day tobacco abstinence at 7 months. Analysis: Logistic regression was used to analyze tobacco abstinence after controlling for potential confounders. Results: Compared to self-referred clients, proactively referred clients were least likely (odds ratio [OR]: 0.88; 95% confidence interval [CI]: 0.81-0.97), whereas passively referred clients were most likely (OR: 1.14; 95% CI: 1.00-1.30) to report tobacco abstinence. Proactively referred (OR: 0.79; 95% CI: 0.70-0.88), but not passively referred, clients were 21% less likely to report tobacco cessation medication use than self-referred clients. Conclusion: Proactive referrals are associated with lower utilization of tobacco cessation medication and less successful quit outcomes; however, provider referrals are critical to reaching tobacco users who may have more significant health risks and barriers to quitting. Examining potential barriers among both providers and provider-referred clients is needed to inform improvements in training providers on brief interventions for tobacco cessation.
  • Higher Plasma Selenium Concentrations Are Associated with Increased Odds of Prevalent Type 2 Diabetes

    Kohler, Lindsay N; Florea, Ana; Kelley, Connor P; Chow, Sherry; Hsu, Paul; Batai, Ken; Saboda, Kathylynn; Lance, Peter; Jacobs, Elizabeth T; Univ Arizona, Coll Med, Nephrol Sect; Univ Arizona, Mel & Enid Zuckerman Coll Publ Hlth; Univ Arizona, Dept Med; Univ Arizona, Ctr Canc (OXFORD UNIV PRESS, 2018-08)
    Background: Selenium, an essential trace element, has been investigated as a potential cancer prevention agent. However, several studies have indicated that selenium supplementation may be associated with an increased risk of type 2 diabetes (T2D), although an equivocal relation of this nature requires confirmation. Objective: We examined the association between baseline plasma concentrations of selenium and the prevalence of T2D, as well as whether participant characteristics or intake of other antioxidant nutrients modified this relation. Methods: We conducted cross-sectional analyses of 1727 participants from the Selenium Trial, a randomized clinical trial of selenium supplementation for colorectal adenoma chemoprevention that had data for baseline selenium plasma concentrations, T2D status, and dietary intake. Logistic regression modeling was used to evaluate the associations between plasma selenium concentrations and prevalent T2D, adjusting for confounding factors. Heterogeneity of effect by participant characteristics was evaluated utilizing likelihood-ratio tests. Results: Mean +/- SD plasma selenium concentrations for those with T2D compared with those without T2D were 143.6 +/- 28.9 and 138.7 +/- 27.2 ng/mL, respectively. After adjustment for confounding, higher plasma selenium concentrations were associated with a higher prevalence of T2D, with ORs (95% CIs) of 1.25 (0.80, 1.95) and 1.77 (1.16, 2.71) for the second and third tertiles of plasma selenium, respectively, compared with the lowest tertile (P-trend = 0.007). No significant effect modification was observed for age, sex, body mass index, smoking, or ethnicity. Increased odds of T2D were seen among those who were in the highest tertile of plasma selenium and the highest category of intake of ss-cryptoxanthin (P-trend = 0.03) and lycopene (P-trend = 0.008); however, interaction terms were not significant. Conclusions: These findings show that higher plasma concentrations of selenium were significantly associated with prevalent T2D among participants in a selenium supplementation trial. Future work is needed to elucidate whether there are individual characteristics, such as blood concentrations of other antioxidants, which may influence this relation.
  • Family history of colorectal cancer in first-degree relatives and metachronous colorectal adenoma

    Jacobs, Elizabeth T.; Gupta, Samir; Baron, John A.; Cross, Amanda J.; Lieberman, David A.; Murphy, Gwen; Martínez, María Elena; Univ Arizona, Mel & Enid Zuckerman Coll Publ Hlth (NATURE PUBLISHING GROUP, 2018-06)
    OBJECTIVES: Little is known about the relationship between having a first-degree relative (FDR) with colorectal cancer (CRC) and risk for metachronous colorectal adenoma (CRA) following polypectomy. METHODS: We pooled data from seven prospective studies of 7697 patients with previously resected CRAs to quantify the relationship between having a FDR with CRC and risk for metachronous adenoma. RESULTS: Compared with having no family history of CRC, a positive family history in any FDR was significantly associated with increased odds of developing any metachronous CRA (OR = 1.14; 95% CI = 1.01-1.29). Higher odds of CRA were observed among individuals with an affected mother (OR = 1.27; 95% CI = 1.05-1.53) or sibling (OR = 1.34; 95% CI = 1.11-1.62) as compared with those without, whereas no association was shown for individuals with an affected father. Odds of having a metachronous CRA increased with number of affected FDRs, with ORs (95% CIs) of 1.07 (0.93-1.23) for one relative and 1.39 (1.02-1.91) for two or more. Younger age of diagnosis of a sibling was associated with higher odds of metachronous CRA, with ORs (95% CIs) of 1.66 (1.08-2.56) for diagnosis at <54 years; 1.34 (0.89-2.03) for 55-64 years; and 1.10 (0.70-1.72) for >65 years (p-trend = 0.008). Although limited by sample size, results for advanced metachronous CRA were similar to those for any metachronous CRA. CONCLUSIONS: A family history of CRC is related to a modestly increased odds of metachronous CRA. Future research should explore whether having a FDR with CRC, particularly at a young age, should have a role in risk stratification for surveillance colonoscopy.
  • Revisiting the Utility of Retrospective Pre-Post Designs: The Need for Mixed-Method Pilot Data

    Geldhof, G. John; Warner, Danielle A.; Finders, Jennifer K.; Thogmartin, Asia A.; Clark, Adam M.; Longway, Kelly A.; Oregon State University; The University of Arizona (Elsevier, 2018-10)
    The retrospective pre-post design affords many benefits to program staff and, accordingly, has piqued renewed interest among applied program evaluators. In particular, the field has witnessed increasing application of a post-program-only data collection strategy in which only posttest and retrospective pretest data are collected. A post-program-only assessment strategy takes considerably less time than is required for collecting pre-program data and presumably has the added benefit of eliminating the impact of response-shift bias. Response-shift bias occurs when the knowledge, skills, or experiences participants gain through program participation leads them to interpret questionnaire items in a qualitatively different manner at pretest versus posttest. In this article, we discuss the strengths and weaknesses associated with administering retrospective pretest assessments and underscore the importance of thoroughly evaluating any application of a retrospective measurement strategy prior to its broader implementation. We provide a practical illustration of this evaluation process using a mixed-method study that assesses one measure of parenting education program effectiveness—the Parenting Skills Ladder.
  • WTI and Brent futures pricing structure

    Scheitrum, Daniel P.; Carter, Colin A.; Revoredo-Giha, Cesar; Univ Arizona (ELSEVIER SCIENCE BV, 2018-05)
    WTI and Brent crude oil futures are competing pricing benchmarks and they jockey for the number one position as the leading futures market. The price spread between WTI and Brent is also an important benchmark itself as the spread affects international trade in oil, refiner margins, and the price of refined products globally. In addition, the shapes of the WTI and Brent futures curves reflect supply and demand fundamentals in the U.S. versus the world market, respectively. On the analysis of the relationship between the two futures prices, we identify a structural break in the WTI Brent price spread in January 2011 and a break in the corresponding shapes of the futures curves around the same time. The structural break was a consequence of a dramatic rise in U.S. production due to fracking, a series of supply disruptions in Europe, binding storage constraints, and the U.S. crude oil export ban. These events are studied in the context of a simulation model of world oil prices. We reproduce the stylized facts of the oil market and conclude that the 2011 break in pricing structure was consistent with standard commodity storage theory. (C) 2018 Elsevier B.V. All rights reserved.
  • Hip Fracture in the Setting of Limited Life Expectancy: The Importance of Considering Goals of Care and Prognosis

    Johnston, C. Bree; Holleran, Amanda; Ong, Thuan; McVeigh, Ursula; Ames, Elizabeth; Univ Arizona, Coll Med, Dept Med (MARY ANN LIEBERT, INC, 2018)
    Importance: Many older patients with a limited life expectancy experience fragility fracture of the hip, and this event is associated with increased risk of premature mortality, functional decline, and institutionalization. The treating team, in collaboration with patients and their families, must determine whether a surgical or conservative approach is in the patient's best interest when a patient has limited life expectancy. Observation: Goals of care discussions appear to be rare in the setting of fragility fracture. The urgent nature of the problem makes such discussions challenging. We believe that many physicians have not considered goals of care discussions to be a standard component of fragility fracture management. Conclusions: We propose that physicians caring for patients with limited life expectancy and fragility fracture of the hip should initiate a goals of care discussion to help determine whether operative repair will be the most patient-centered approach. Training on conducting goals of care discussions should be a standard part of surgical training programs. Goals of care discussions should include prognosis, patient values and preferences, pain, likelihood for functional recovery, and burdens and benefits of surgical versus nonsurgical management. Multidisciplinary input is required, and many patients will benefit from geriatric and/or palliative care team involvement.
  • Computed stabilization for a giant fullerene endohedral: Y2C2@C1(1660)-C108

    Slanina, Zdeněk; Uhlík, Filip; Pan, Changwang; Akasaka, Takeshi; Lu, Xing; Adamowicz, Ludwik; Univ Arizona, Dept Chem & Biochem (Elsevier, 2018-10-16)

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