• Host-free biofilm culture of “Candidatus Liberibacter asiaticus,” the bacterium associated with Huanglongbing

      Ha, Phuc T.; He, Ruifeng; Killiny, Nabil; Brown, Judith K.; Omsland, Anders; Gang, David R.; Beyenal, Haluk; Univ Arizona, Sch Plant Sci (Elsevier BV, 2019-12)
      Inability to culture the phloem-restricted alpha-proteobacterium “Candidatus Liberibacter asiaticus” (“Ca. L. asiaticus”) or the closely related species (“Candidatus Liberibacter americanus” and “Candidatus Liberibacter africanus”) that are associated with Huanglongbing (HLB) hampers the development of effective long-term control strategies for this devastating disease. Here we report successful establishment and long-term maintenance of host-free “Ca. L. asiaticus” cultures, with the bacterium growing within cultured biofilms derived from infected citrus tissue. The biofilms were grown in a newly designed growth medium under specific conditions. The initial biofilm-based culture has been successfully maintained for over two years and has undergone over a dozen subcultures. Multiple independent cultures have been established and maintained in a biofilm reactor system, opening the door to the development of pure culture of “Ca. L. asiaticus” and the use of genetics-based methods to understand and mitigate the spread of HLB.
    • Provenance of invaders has scale-dependent impacts in a changing wetland ecosystem

      Amatangelo, Kathryn L.; Stevens, Lee; Wilcox, Douglas A.; Jackson, Stephen T.; Sax, Dov F.; Amatangelo, Kathryn L.; Stevens, Lee; Wilcox, Douglas A.; Jackson, Stephen T.; Sax, Dov F.; et al. (PENSOFT PUBL, 2019-11-19)
      Exotic species are associated with a variety of impacts on biodiversity, but it is unclear whether impacts of exotic specks differ from those of native species with similar growth forms or native species invading disturbed sites. We compared presence and abundance of native and exotic invaders with changes in wetland plant species diversity over a 28-year period by re-surveying 22 ponds to identify factors correlated with observed changes. We also compared communities found within dense patches of native and exotic emergent species with similar habits. Within patches, we found no categorical diversity differences between areas dominated by native or exotic emergent species. At the pond scale, the cover of the exotic grass Phragmites australis best predicted change in diversity and evenness over time, likely owing to its significant increase in coverage over the study period. These changes in diversity and evenness were strongest in younger, less successionally-advanced ponds. Changes associated with cover of P. australis in these ponds were not consistent with expected diversity decreases, but instead with a dampening of diversity gains, such that the least-invaded ponds increased in diversity the most over the study period. There were more mixed effects on evenness, ranging from a reduction in evenness gains to actual losses of evenness in the ponds with highest invader cover. In this wetland complex, the habit, origin and invasiveness of species contribute to diversity responses in a scale- and context-dependent fashion. Future efforts to preserve diversity should focus on preventing the arrival and spread of invaders that have the potential to cover large areas at high densities, regardless of their origin. Future studies should also investigate more thoroughly how changes in diversity associated with species invasions are impacted by other ongoing ecosystem changes.
    • Subsurface Cl-bearing salts as potential contributors to recurring slope lineae (RSL) on Mars

      Wang, Alian; Ling, Zongcheng; Yan, Yuanchao; McEwen, Alfred S.; Mellon, Michael T.; Smith, Michael D.; Jolliff, Bradley L.; Head, James; Univ Arizona, Lunar & Planetary Lab (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2019-11-15)
      We report laboratory experimental results that support a brine-related hypothesis for the recurring slope lineae (RSL) on Mars in which the subsurface Cl-salts, i.e., hydrous chlorides and oxychlorine salts (HyCOS) are the potential source materials. Our experiments revealed that within the observed RSL temperature window T-RSL (250-300 K), the deliquescence of HyCOS could occur in relative humidity ranges (RH >= 22%-46%) much lower than those for hydrous (Mg, Fe)-sulfates (RH >= 75%-96%). In addition, we demonstrated that the RH values kept by common HyCOS and hydrous sulfates in enclosures have a general trend as RHsulfates > RHperchlorates > RHchlorides (with same type of cation) in wide T range. It means that the required RH range for a Cl-bearing salt to deliquescence can be satisfied by a co-existing salt of different type, e.g., in the subsurface layers of mixed salts on Mars. Furthermore, we found a strong temperature dependence of the deliquescence rates for all tested HyCOS, e.g., a duration of 1-5 sols for all HyCOS at the high end (300 K) of T-RSL, and of 20-70 sols for all tested HyCOS (except NaClO4 center dot H2O) at the low end (250 K) of T-RSL, which is consistent with the observed seasonal behavior of RSL on Mars. From a mass-balance point of view, the currently observed evidences on Mars do not support a fully-brine-wetted track model, thus we suggest a brine-triggered granular-flow model for the most RSL. Considering the recurrence of RSL in consecutive martian years, our experimental results support the rehydration of remnant HyCOS layers during a martian cold season through H2O vapor-to-salt direct interaction. We found that the evidences of HyCOS rehydration under Mars relevant P-T-RH conditions are detectable in a few minutes by in situ Raman spectroscopy. This rehydration would facilitate the recharge of H2O back into subsurface HyCOS, which could serve as the source material to trigger RSL in a subsequent warm season. The major limiting factor for this rehydration is the H2O supply, i.e., the H2O vapor density carried by current Mars atmospheric circulation and the diffusion rate of H2O vapor into the salt-rich subsurface in a cold season. In a worst-case scenario, these H2O supplies can support a maximum increase of hydration degrees of two for totally dehydrated HyCOS, whereas the full rehydration of subsurface HyCOS layers can be easily reached during a > 30 degrees obliquity period that has H2O vapor density 10 x to 20 x times the value of current obliquity. Overall, our results imply the existence of a large amount of Cl-bearing salts in the subsurface at RSL sites.
    • Global characteristics of gravity waves in the upper atmosphere of Mars as measured by MAVEN/NGIMS

      Siddle, A.G.; Mueller-Wodarg, I.C.F.; Stone, S.W.; Yelle, R.V.; Univ Arizona, Lunar & Planetary Lab (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2019-11-15)
      We present an analysis of gravity waves in Mars' upper atmosphere above 120 km. Using in-situ data from NGIMS onboard MAVEN we have been able to characterise waves from nearly 4000 orbits. We have used temperature and density profiles to extract perturbations and interpret these as vertically propagating gravity waves which we characterise by their amplitude and wavelength. In this region of the atmosphere gravity waves have amplitudes of around 10%. Vertical wavelengths are found to be around 10-30 km. We observe an increase in gravity wave amplitudes with increasing solar zenith angle. Gravity wave amplitudes appear invariant in altitude on the dayside, however increase with altitude on the nightside.
    • Measurements of I-129 in the Pacific Ocean at Scripps Pier and Pacific Northwest sites: A search for effects from the 2011 Fukushima Daiichi Nuclear Power Plant accident and Hanford

      Chang, Ching-Chih; Burr, George S; Jull, A J Timothy; Russell, Joellen; Priyadarshi, Antra; Lin, Mang; Thiemens, Mark; Biddulph, Dana; Univ Arizona, AMS Lab; Univ Arizona, Dept Geosci (ELSEVIER, 2019-11-01)
      Radionuclides from the Fukushima Daiichi Nuclear Power Plant were released directly into the ocean as a result of the Great East Japan Earthquake on March 11, 2011. This material became entrained in surface ocean currents and subsequently transported for great distances. In June 2011, a few months after the disaster, we began a surface ocean 129I monitoring program, with samples from Scripps Pier, La Jolla, California, USA, with the expectation that surface currents originating off the east coast of Japan would eventually carry radionuclides to the La Jolla site. After 7 years of ocean transport, a distinct signal has not yet arrived at Scripps Pier. We have however, recorded an interesting systematic seasonal 129I time series record that stems from surface circulation variations along the California coast. To provide a more comprehensive picture of the 129I budget in coastal surface waters off the west coast of the U.S., we also include 129I data from the Columbia River, and offshore sites along the coast of Washington State. Anthropogenic nuclides are carried by the Columbia River into the Pacific Ocean from the vicinity of the decommissioned Hanford nuclear facility. We find highly elevated 129I/127I values in the Columbia River, downstream from the Hanford site, but this anthropogenic 129I becomes significantly diluted once it reaches the Pacific Ocean. Nonetheless, its imprint persists in surface seawater off the west coast of the U.S. that has significantly higher 129I/127I levels than other surface sites in the Pacific Ocean.
    • Which Countries Have More Open Governments? Assessing Structural Determinants of Openness

      Schnell, Sabina; Jo, Suyeon; Univ Arizona, Sch Govt & Publ Policy, Publ Management (SAGE PUBLICATIONS INC, 2019-11)
      An increasing number of countries are adopting open government reforms, driven, in part, by the Open Government Partnership (OGP), a global effort dedicated to advancing such initiatives. Yet, there is still wide variation in openness across countries. We investigate the political, administrative, and civic factors that explain this variation, using countries' fulfillment of OGP eligibility criteria as a proxy for minimum standards of openness. We find that countries with strong constraints on the executive and high levels of citizen education have governments that are more open. A dense network of civil society organizations is associated with more budget transparency and higher civil liberties, but not with access to information or asset disclosure laws. The results suggest that if the value of openness is to be translated in practice, it is not enough to have capable bureaucracies-countries also need informed citizens and strong oversight of executive agencies.
    • Affection substitution: The effect of pornography consumption on close relationships

      Hesse, Colin; Floyd, Kory; Univ Arizona (SAGE PUBLICATIONS LTD, 2019-11)
      Scholars have stated that humans have a fundamental need to belong, but less is known about whether individuals can use other resources to substitute for close relationships. In this study, 357 adults reported their level of affection deprivation, their weekly pornography consumption, their goals for using pornography (including life satisfaction and loneliness reduction), and indicators of their individual and relational wellness. We hypothesized that individuals might consume pornography as a coping mechanism (either adaptive or maladaptive) to deal with affection deprivation, with affection deprivation relating to the goals for using pornography and consumption potentially moderating the relationships between affection deprivation and the outcome measures. As predicted, affection deprivation and pornography consumption were inversely related to relational satisfaction and closeness, while being positively related to loneliness and depression. Affection deprivation was positively related with most stated goals for pornography use (although the relationship between affection deprivation and pornography consumption was nonsignificant). The moderation hypothesis, however, showed little evidence, yielding a moderating effect only on the relationship between affection deprivation and depression (with nonsignificant effects for relational satisfaction, closeness, and loneliness). Overall, there is some evidence that pornography consumption is used as a form of affection substitution (dealing with the perception of affection deprivation). However, there is no evidence of consumption being either adaptive or maladaptive when it comes to relationship satisfaction, closeness, and loneliness, although it is possibly maladaptive in terms of depression.
    • Root-driven weathering impacts on mineral-organic associations in deep soils over pedogenic time scales

      Garcia Arredondo, Mariela; Lawrence, Corey R.; Schulz, Marjorie S.; Tfaily, Malak M.; Kukkadapu, Ravi; Jones, Morris E.; Boye, Kristin; Keiluweit, Marco; Univ Arizona, Soil Water & Environm Sci Dept (PERGAMON-ELSEVIER SCIENCE LTD, 2019-10-15)
      Plant roots are critical weathering agents in deep soils, yet the impact of resulting mineral transformations on the vast deep soil carbon (C) reservoir are largely unknown. Root-driven weathering of primary minerals may cause the formation of reactive secondary minerals, which protect mineral-organic associations (MOAs) for centuries or millennia. Conversely, root-driven weathering may also transform secondary minerals, potentially enhancing the bioavailability of C previously protected in MOAs. Here we examined the impact of root-driven weathering on MOAs and their capacity to store C over pedogenic time scales. To accomplish this, we examined deep horizons (100-160 cm) that experienced root-driven weathering in four soils of increasing ages (65-226 kyr) of the Santa Cruz marine terrace chronosequence. Specifically, we compared discrete rhizosphere zones subject to root-driven weathering, with adjacent zones that experienced no root growth. Using a combination of radiocarbon, mass spectrometry, Fe-57 Mossbauer spectroscopy, high-resolution mass spectrometry, and X-ray spectromicroscopy approaches, we characterized transformations of MOAs in relation to changes in C content, Delta C-14 values, and chemistry across the chronosequence. We found that the onset of root-driven weathering (65-90 kyr) increased the amount of C associated with poorly crystalline iron (Fe) and aluminum (Al) phases, particularly highly disordered nano-particulate goethite (np-goethite). This increase coincided with greater C concentrations, lower Delta C-14 values, and greater abundance of what is likely microbially-derived C. Continued root-driven weathering (137-226 kyr) did not significantly change the amount of C associated with crystalline Fe and Al phases, but resulted in a decline in the amount of C associated with poorly crystalline Fe and Al phases. This decline coincided with a decrease in C concentrations, an increase in Delta C-14 values, and a shift toward plant-derived C. In contrast, soil not affected by root-driven weathering showed comparatively low amounts of C bound to poorly crystalline Fe and Al phases regardless of soil age and, correspondingly, lower C concentrations. Our results demonstrate that root-driven formation and disruption of MOAs are direct controls on both C accrual and loss in deep soil. This finding suggests that root impacts on soil C storage are dependent on soil weathering stage, a consideration that is critical for future predictions of the vulnerability of deep soil C to global change.
    • Influence of Inflammatory and Oxidative Stress Pathways on Longitudinal Symptom Experiences in Children With Leukemia

      Hockenberry, Marilyn J; Pan, Wei; Scheurer, Michael E; Hooke, Mary C; Taylor, Olga; Koerner, Kari; Montgomery, David; Whitman, Susan; Mitby, Pauline; Moore, Ida; et al. (SAGE PUBLICATIONS INC, 2019-10-01)
      Purpose: The purpose of this study was to explore the influence of oxidative stress (F2-isoprostanes) and inflammatory (interleukin [IL]-8) biomarkers on symptom trajectories during the first 18 months of childhood leukemia treatment. Method: A repeated-measures design was used to evaluate symptoms experienced by 218 children during treatment. A symptom cluster (fatigue, pain, and nausea) was explored over four time periods: initiation of post-induction therapy, 4 and 8 months into post-induction therapy, and the beginning of maintenance therapy (12 months postinduction). F2-isoprostanes and IL-8 were evaluated in cerebrospinal fluid (CSF) samples collected at baseline (diagnosis) and then at the four time periods. The longitudinal relationships of these biomarkers with the symptom cluster were examined using the longitudinal parallel process. Results: Pain and fatigue levels were highest during the post-induction phases of treatment and decreased slightly during maintenance therapy, while nausea scores were relatively stable. Even in the later phases of treatment, children continued to experience symptoms. CSF levels of the biomarkers increased during the post-induction phases of treatment. Early increases in the biomarkers were associated with more severe symptoms during the same period; patients who had increased biomarkers over time also experienced more severe symptoms over time. Conclusions: Findings reveal that children experienced symptoms throughout the course of leukemia treatment and support hypothesized longitudinal relationships of oxidative stress and inflammatory biomarkers with symptom severity. Activation of the biomarker pathways during treatment may explain underlying mechanisms of symptom experiences and identify which children are at risk for severe symptoms.
    • Instability in a coiled-coil signaling helix is conserved for signal transduction in soluble guanylyl cyclase

      Weichsel, Andrzej; Kievenaar, Jessica A; Curry, Roslyn; Croft, Jacob T; Montfort, William R; Univ Arizona, Dept Chem & Biochem (WILEY, 2019-10-01)
      How nitric oxide (NO) activates its primary receptor, α1/β1 soluble guanylyl cyclase (sGC or GC‐1), remains unknown. Likewise, how stimulatory compounds enhance sGC activity is poorly understood, hampering development of new treatments for cardiovascular disease. NO binding to ferrous heme near the N‐terminus in sGC activates cyclase activity near the C‐terminus, yielding cGMP production and physiological response. CO binding can also stimulate sGC, but only weakly in the absence of stimulatory small‐molecule compounds, which together lead to full activation. How ligand binding enhances catalysis, however, has yet to be discovered. Here, using a truncated version of sGC from Manduca sexta, we demonstrate that the central coiled‐coil domain, the most highly conserved region of the ~150,000 Da protein, not only provides stability to the heterodimer but is also conformationally active in signal transduction. Sequence conservation in the coiled coil includes the expected heptad‐repeating pattern for coiled‐coil motifs, but also invariant positions that disfavor coiled‐coil stability. Full‐length coiled coil dampens CO affinity for heme, while shortening of the coiled coil leads to enhanced CO binding. Introducing double mutation αE447L/βE377L, predicted to replace two destabilizing glutamates with leucines, lowers CO binding affinity while increasing overall protein stability. Likewise, introduction of a disulfide bond into the coiled coil results in reduced CO affinity. Taken together, we demonstrate that the heme domain is greatly influenced by coiled‐coil conformation, suggesting communication between heme and catalytic domains is through the coiled coil. Highly conserved structural imperfections in the coiled coil provide needed flexibility for signal transduction.
    • Experience with morphosyntactic paradigms allows toddlers to tacitly anticipate overregularized verb forms months before they produce them

      Figueroa, Megan; Gerken, LouAnn; Univ Arizona, Dept Psychol (ELSEVIER, 2019-10)
      When do children acquire abstract grammatical categories? Studies of 2- to 3-year-olds' productions of complete morphosyntactic paradigms (e.g., all legal determiners with all nouns) suggest relatively later category acquisition, while studies of infant discrimination of grammatical vs. ungrammatical sequences suggest earlier acquisition. However, few of the latter studies have probed category generalization by examining how learners treat gaps in their input, and none have found evidence that learners before the age of 2 years fill gaps in VERB paradigms. Therefore, the three experiments presented here asked whether 16-month-olds tacitly expect to hear forms like breaked by presenting them with overregularized verbs vs. (1) nonce verbs + -ed, (2) real English nouns + -ed and (3) the correct irregular counterparts. The pattern of listening preferences suggests that toddlers anticipate overregularized forms, suggesting that they have a general proto-category VERB, to which they expect the complete set of verb inflections to apply.
    • Comparative life cycle analysis for value recovery of precious metals and rare earth elements from electronic waste

      Li, Zhen; Diaz, Luis A.; Yang, Zhiyao; Jin, Hongyue; Lister, Tedd E.; Vahidi, Ehsan; Zhao, Fu; Univ Arizona, Dept Syst & Ind Engn (ELSEVIER, 2019-10)
      There is an ever-increasing concern regarding the electronic waste (e-waste), which is the fastest growing waste stream in the world. Incentivized by various legislations and the intrinsic value of critical metals inside, recycling of e-waste is becoming an attractive business opportunity that also benefits the environment. A novel electrochemical recovery (ER) process has been developed as a promising alternative to the existing pyrometallurgical and hydrometallurgical processes based technologies to recover base metals, precious metals, and rare earth elements (REEs) from e-waste. Experimental results indicate that the ER process has lower chemical consumption, enhanced control, and reduced energy demand compared to the pyrometallurgical and the hydro metallurgical processes. To quantify and compare the environmental performances of the three technologies, life cycle analysis has been conducted. Results show that the ER process outperforms the other two processes in almost all impact categories adopted in TRACI and ILCD while there is no clear winner between the hydro metallurgical and the pyrometallurgical processes. The highest impactful input for the ER method is hydrochloric acid, and for the pyrometallurgical method is copper scrap, while for the hydrometallurgical method, it is hydrogen peroxide, an oxidizer that accelerates base metal extraction process, that dominates the overall environmental footprint. The environmental viability of the ER process warrants the further development of ER process at industrial scale.
    • Measurement of Patients' Perceptions of the Quality of Acute Stroke Services: Development and Validation of the STROKE Perception Report

      Alexandrov, Anne W; Brewer, Barbara B; Moore, Kari; Grau, Charlene; Beenstock, Dana J; Cudlip, Fern; Murphy, Deborah A; Klassman, Lynn; Korsnack, Andrea M; Johnson, Brenda; et al. (LIPPINCOTT WILLIAMS & WILKINS, 2019-10)
      INTRODUCTION: Patients' perceptions of healthcare quality have become an important part of quality measurement. We explored patients' and family's lived experiences during acute stroke hospitalization to develop a quantitative instrument. METHODS: Focus groups were conducted using open-ended scripted questions. Interview data were coded and analyzed using an inductive approach to thematic analysis. Symmetric patient and family instruments were developed based on qualitative domains and serially refined to a set of 30 survey items, 12 stroke knowledge test items, and 5 subject demographic fields. Scales were evaluated for internal consistency reliability using Cronbach alpha; construct validity with exploratory factor analysis using principal components with varimax rotation was performed to determine the extent to which items in a scale measure the same underlying factor. Feasibility of an electronic cloud-based survey was also tested. RESULTS: Three main themes emerged: fast action to diagnose and treat stroke, genuine caring, and education to prevent and respond to stroke. A total of 1029 subjects completed the final instrument with no differences in perception found by race, ethnicity, or length of stay. Scales showed satisfactory internal consistency reliability (Cronbach alpha scores, .89-.94); factor loadings across each scale ranged from 0.55 to 0.87. Data entry by electronic pad was perceived by 77% to be more confidential than paper surveys; median score for difficulty was 4 ("easy to use"). CONCLUSION: The STROKE Perception Report enables understanding of patients' and family's beliefs about the quality of acute stroke care in essential new domains never explored before.
    • Exogenous progesterone for smoking cessation in men and women: a pilot double-blind, placebo-controlled randomized clinical trial

      Tosun, Nicole L; Fieberg, Ann M; Eberly, Lynn E; Harrison, Katherine A; Tipp, Angela R; Allen, Alicia M; Allen, Sharon S; Univ Arizona, Dept Family & Community Med (WILEY, 2019-10)
      Background and Aims: In some clinical studies men and women have been found to differ in their ability to quit smoking, perhaps as a result of progesterone. The primary aim of this study was to provide a preliminary test of whether progesterone (PRO), compared with placebo (PBO), was more effective for smoking cessation in men and women. Design: Pilot double-blind, placebo-controlled randomized clinical trial. Setting: Minneapolis/St Paul metro area, Minnesota, USA. Participants: A total of 216 participants were randomized, including 113 men (18-60 years; PRO = 56, PBO = 57) and 103 women (18-50 years, pre-menopausal with self-reported regular menstrual cycles; PRO = 51, PBO = 52). Intervention: Participants were randomized (1 : 1 within sex group) to either PRO (200 mg twice daily) or PBO. Participants were assigned a quit date approximately 7 days after starting medication (luteal phase for women) and were followed for 12 weeks to assess relapse. Measurements The primary outcome was self-reported 7-day point prevalence abstinence (PPA) at week 4. Secondary outcomes included 7-day PPA at weeks 8 and 12, prolonged abstinence, continuous abstinence, urine cotinine < 50 ng/ml, expired carbon monoxide <= 5 parts per million (p.p.m.) and days to relapse. Findings: There was a significant difference in 7-day PPA at week 4 among women [PRO: 18 (35.3%) versus PBO: 9 (17.3%), odds ratio (OR) = 2.61, 95% confidence interval (CI) = 1.04, 6.54, P = 0.041], but not among men [PRO: 13 (23.2%) versus PBO: 12 (21.1%), 1.13 (0.47, 2.76), P = 0.782]. There was some evidence that PRO delayed relapse in women (days to relapse; PRO: 20.5 +/- 29.6 versus PBO: 14.3 +/- 26.8, P = 0.03) but not in men (PRO: 13.4 +/- 25.9 versus PBO: 13.3 +/- 23.8, P = 0.69). Conclusions: Oral micronized progesterone may aid smoking cessation in women.
    • Health-seeking behaviors and health information gathering in older Mexican American males

      Ortiz-Dowling, Evangeline M.; Der Ananian, Cheryl; Larkey, Linda K.; Hooker, Steven P.; Univ Arizona, Coll Nursing (EDUCATIONAL PUBLISHING FOUNDATION-AMERICAN PSYCHOLOGICAL ASSOC, 2019-10)
      Evidence suggests that men's health disparities are linked to attitudes and beliefs toward health promotion and risk reduction, participation in high-risk behaviors, and limited health care access and use influenced by socioeconomic challenges. However, we know less about the specific factors related to health disparities in older Mexican American males. The purpose of this study was to explore the cultural. social, environmental, and gender factors influencing health-seeking behaviors and health information gathering in older Mexican American males. In-depth interviews were conducted with 14 older Mexican American males aged 65-80 years. Based on language preference, interviews were conducted in either Spanish or English. A standardized moderator's guide was used to examine the participant's perceptions of health, maintenance of health, gender influences on health, and sources of men's health information and health promotion programs. Data were collected, organized, and analyzed following the methodology of transcendental phenomenology and the social ecological model. Two major themes related to health-seeking behaviors and health information gathering emerged: (a) top external sources heeded include women, health care providers, and the Internet and (b) men regard inner prompts for self-determined self-care. Future research should consider these external sources and inner prompts when developing targeted health promotion interventions, such as physical activity programs, with older Mexican American males.
    • Node-Link or Adjacency Matrices: Old Question, New Insights

      Okoe, Mershack; Jianu, Radu; Kobourov, Stephen; Univ Arizona (IEEE COMPUTER SOC, 2019-10)
      Visualizing network data is applicable in domains such as biology, engineering, and social sciences. We report the results of a study comparing the effectiveness of the two primary techniques for showing network data: node-link diagrams and adjacency matrices. Specifically, an evaluation with a large number of online participants revealed statistically significant differences between the two visualizations. Our work adds to existing research in several ways. First, we explore a broad spectrum of network tasks, many of which had not been previously evaluated. Second, our study uses two large datasets, typical of many real-life networks not explored by previous studies. Third, we leverage crowdsourcing to evaluate many tasks with many participants. This paper is an expanded journal version of a Graph Drawing (GD'17) conference paper. We evaluated a second dataset, added a qualitative feedback section, and expanded the procedure, results, discussion, and limitations sections.
    • Defective Transcriptional Programming of Effector CD8 T Cells in Aged Mice Is Cell-Extrinsic and Can Be Corrected by Administration of IL-12 and IL-18

      Jergović, Mladen; Thompson, Heather L.; Renkema, Kristin R.; Smithey, Megan J.; Nikolich-Žugich, Janko; Univ Arizona, Dept Immunobiol, Coll Med Tucson; Univ Arizona, Ctr Aging, Coll Med Tucson (FRONTIERS MEDIA SA, 2019-09-18)
      In response to infection with intracellular microorganisms, old mice mobilize decreased numbers of antigen-specific CD8T cells with reduced expression of effector molecules and impaired cytolytic activity. Molecular mechanisms behind these defects and the cell-intrinsic (affecting naive CD8 T cells themselves) vs. extrinsic, microenvironmental origin of such defects remain unclear. Using reciprocal transfer experiments of highly purified naive T cells from adult and old transgenic OT-1 mice, we decisively show that the dominant effect is cell-extrinsic. Naive adult OT-1 T cells failed to expand and terminally differentiate in the old organism infected with Listeria-OVA. This defect was preceded by blunted expression of the master transcription factor T-bet and impaired glycolytic switch when T cells are primed in the old organism. However, both old and adult naive CD8T cells proliferated and produced effector molecules to a similar extent when stimulated in vitro with polyclonal stimuli, as well as when transferred into adult recipients. Multiple inflammatory cytokines with direct effects on T cell effector differentiation were decreased in spleens of old animals, particularly IL-12 and IL-18. Of note, in vivo treatment of mice with IL-12 and IL-18 on days 4-6 of Listeria infection reconstituted cytotoxic T cell response of aged mice to the level of adult. Therefore, critical cytokine signals which are underproduced in the old priming environment can restore proper transcriptional programming of old naive CD8T cells and improve immune defense against intracellular microorganisms.
    • Transfusion independence after repeated haploidentical hematopoietic cell transplants in a patient with congenital dyserythropoietic anemia type II and hemosiderosis

      Macaraeg, Marci; Proytcheva, Maria; Katsanis, Emmanuel; Univ Arizona, Dept Pediat; Univ Arizona, Dept Pathol; Univ Arizona, Dept Med; Univ Arizona, Dept Immunobiol (WILEY, 2019-09-17)
      Matched related or unrelated donor allogeneic HCT has occasionally been applied in patients with severe CDA type II and proven to be curative. We report on the first patient with CDA to undergo haploidentical bone marrow transplantation with PT-CY. A 12-year-old boy with severe hemosiderosis, and a, consequently, disturbed BM microenvironment, developed recurrent graft failures and required salvage with two additional haploidentical HCTs. He achieved complete donor chimerism and transfusion independence after the third HCT. Our case underscores the risks associated with performing haploidentical HCT in older pediatric patients with CDA and severe chronic iron overload.
    • Modification of spintronic terahertz emitter performance through defect engineering

      Nenno, Dennis M; Scheuer, Laura; Sokoluk, Dominik; Keller, Sascha; Torosyan, Garik; Brodyanski, Alexander; Lösch, Jörg; Battiato, Marco; Rahm, Marco; Binder, Rolf H; et al. (NATURE PUBLISHING GROUP, 2019-09-16)
      Spintronic ferromagnetic/non-magnetic heterostructures are novel sources for the generation of THz radiation based on spin-to-charge conversion in the layers. The key technological and scientific challenge of THz spintronic emitters is to increase their intensity and frequency bandwidth. Our work reveals the factors to engineer spintronic Terahertz generation by introducing the scattering lifetime and the interface transmission for spin polarized, non-equilibrium electrons. We clarify the influence of the electron-defect scattering lifetime on the spectral shape and the interface transmission on the THz amplitude, and how this is linked to structural defects of bilayer emitters. The results of our study define a roadmap of the properties of emitted as well as detected THz-pulse shapes and spectra that is essential for future applications of metallic spintronic THz emitters.
    • A detailed investigation of pretreatment protocols for high precision radiocarbon measurements of annual tree-rings

      Lange, T.E.; Nordby, J.A.; Murphy, P.L.O.; Hodgins, G.W.L.; Pearson, C.L.; Univ Arizona, AMS Lab; Univ Arizona, Lab Tree Ring Res (ELSEVIER, 2019-09-15)
      Much discussion has revolved around proper sample types and pretreatment methods to generate a calibration dataset that would allow for the most accurate representation of an unknown sample's calendar age. Since the development of radiocarbon dating, tree-rings have played a vital role in the creation of global calibration datasets, with these samples being subjected to varying degrees of both physical and chemical pretreatments. With an international move away from multi-ring composite measurements and toward higher resolution annual and/or sub-annual measurement of radiocarbon content, and with the on-set of a major new research project using, primarily the highly resinous North American Bristlecone Pine, we set out to review sample preparation procedures. The question became; which fraction, and therefore how much pretreatment is really necessary in order to extract the most representative and replicable C(14 )determination in a tree-ring for any given growth year, and could it be both specimen as well as species dependent? For this study, a total of four samples were chosen. These samples consisted of two rings from two different years from Bristlecone Pine and two rings from these same years from Irish Oak. These rings were each treated with a series of progressively more aggressive chemical treatments allowing for the extraction of different fractions from each ring. An analysis of the different pretreatment methods, as well as interspecies variance, is discussed.