Now showing items 8298-8317 of 14016

    • The Post-starburst Evolution of Tidal Disruption Event Host Galaxies

      French, K. Decker; Arcavi, I.; Zabludoff, Ann; Univ Arizona, Steward Observ (IOP PUBLISHING LTD, 2017-01-30)
      We constrain the recent star formation histories of the host galaxies of eight optical/UV-detected tidal disruption events (TDEs). Six hosts had quick starbursts of <200 Myr duration that ended 10-1000 Myr ago, indicating that TDEs arise at different times in their hosts' post-starburst evolution. If the disrupted star formed in the burst or before, the post-burst age constrains its mass, generally excluding O, most B, and highly massive A stars. If the starburst arose from a galaxy merger, the time since the starburst began limits the coalescence timescale and thus the merger mass ratio to more equal than 12: 1 in most hosts. This uncommon ratio, if also that of the central supermassive black hole (SMBH) binary, disfavors the scenario in which the TDE rate is boosted by the binary but is insensitive to its mass ratio. The stellar mass fraction created in the burst is 0.5%-10% for most hosts, not enough to explain the observed 30-200x. boost in TDE rates, suggesting that the host's core stellar concentration is more important. TDE hosts have stellar masses 10(9.4)-10(10.3) M circle dot,consistent with the Sloan Digital Sky Survey volume-corrected, quiescent Balmer-strong comparison sample and implying SMBH masses of 10(5.5)-10(7.5) M circle dot, Subtracting the host absorption line spectrum, we uncover emission lines; at least five hosts have ionization sources inconsistent with star formation that instead may be related to circumnuclear gas, merger shocks, or post-AGB stars.
    • Post-transcriptional Inhibition of Hsc70-4/HSPA8 Expression Leads to Synaptic Vesicle Cycling Defects in Multiple Models of ALS

      Coyne, Alyssa N.; Lorenzini, Ileana; Chou, Ching-Chieh; Torvund, Meaghan; Rogers, Robert S.; Starr, Alexander; Zaepfel, Benjamin L.; Levy, Jennifer; Johannesmeyer, Jeffrey; Schwartz, Jacob C.; et al. (CELL PRESS, 2017-10)
      Amyotrophic lateral sclerosis (ALS) is a synaptopathy accompanied by the presence of cytoplasmic aggregates containing TDP-43, an RNA-binding protein linked to similar to 97% of ALS cases. Using a Drosophila model of ALS, we show that TDP-43 overexpression (OE) in motor neurons results in decreased expression of the Hsc70-4 chaperone at the neuromuscular junction (NMJ). Mechanistically, mutant TDP-43 sequesters hsc70-4 mRNA and impairs its translation. Expression of the Hsc70-4 ortholog, HSPA8, is also reduced in primary motor neurons and NMJs of mice expressing mutant TDP-43. Electrophysiology, imaging, and genetic interaction experiments reveal TDP-43-dependent defects in synaptic vesicle endocytosis. These deficits can be partially restored by OE of Hsc70-4, cysteine-string protein (Csp), or dynamin. This suggests that TDP-43 toxicity results in part from impaired activity of the synaptic CSP/Hsc70 chaperone complex impacting dynamin function. Finally, Hsc70-4/HSPA8 expression is also post-transcriptionally reduced in fly and human induced pluripotent stem cell (iPSC) C9orf72 models, suggesting a common disease pathomechanism.
    • Post-transplant bendamustine reduces GvHD while preserving GvL in experimental haploidentical bone marrow transplantation

      Stokes, Jessica; Hoffman, Emely A.; Zeng, Yi; Larmonier, Nicolas; Katsanis, Emmanuel; University of Arizona; Department of Pediatrics; University of Arizona; Tucson Arizona; Department of Pediatrics; University of Arizona; Tucson Arizona; Department of Pediatrics; University of Arizona; Tucson Arizona; Department of Pediatrics; University of Arizona; Tucson Arizona; et al. (WILEY-BLACKWELL, 2016-07)
      Advances in haploidentical bone marrow transplantation (h-BMT) have drastically broadened the treatment options for patients requiring BMT. The possibility of significantly reducing the complications resulting from graft-versus-host disease (GvHD) with the administration of post-transplant cyclophosphamide (PT-CY) has substantially improved the efficacy and applicability of T cell-replete h-BMT. However, higher frequency of disease recurrence remains a major challenge in h-BMT with PT-CY. There is a critical need to identify novel strategies to prevent GvHD while sparing the graft-versus-leukaemia (GvL) effect in h-BMT. To this end, we evaluated the impact of bendamustine (BEN), given post-transplant, on GvHD and GvL using clinically relevant murine h-BMT models. We provide results indicating that post-transplant bendamustine (PT-BEN) alleviates GvHD, significantly improving survival, while preserving engraftment and GvL effects. We further document that PT-BEN can mitigate GvHD even in the absence of Treg. Our results also indicate that PT-BEN is less myelo-suppressive than PT-CY, significantly increasing the number and proportion of CD11b(+)Gr-1(hi) cells, while decreasing lymphoid cells. In vitro we observed that BEN enhances the suppressive function of myeloid-derived suppressor cells (MDSCs) while impairing the proliferation of T-and B-cells. These results advocate for the consideration of PT-BEN as a new therapeutic platform for clinical implementation in h-BMT.
    • Posterior atlantoaxial fixation: A cadaveric and fluoroscopic step-by-step technical guide

      Baaj, AliA; Sattarov, Kamran; Skoch, Jesse; Abbasifard, Salman; Patel, AparS; Avila, MauricioJ; Walter, ChristinaM; Department of Surgery, Division of Neurosurgery, University of Arizona Medical Center (MedKnow, 2015)
      Background: Atlantoaxial surgical fixation is widely employed treatment strategy for a myriad of pathologies affecting the stability of the atlantoaxial joint. The most common technique used in adults, and in certain cases in children, involves a posterior construct with C1 lateral mass screws, and C2 pars or pedicle screws. This technical note aims to provide a step‑by‑step guide to this procedure using cadaveric and fluoroscopic images. Methods: An embalmed, human, cadaveric, specimen was used for this study. The subject did not have obvious occipital‑cervical pathology. Dissections and techniques were performed to mimic actual surgical technique. Photographs were taken during each step, and the critical aspects of each step were highlighted. Fluoroscopic images from a real patient undergoing C1/C2 fixation were also utilized to further highlight the anatomic‑radiographic relationships. This study was performed without external or industry funding. Results: Photographic and radiographic pictures and drawings are presented to illustrate the pertinent anatomy and technical aspects of this technique. The nuances of each step, including complication avoidance strategies are also highlighted. Conclusions: Given the widespread utilization of this technique, described step‑by‑step guide is timely for surgeons and trainees alike.
    • Postnatal β2 adrenergic treatment improves insulin sensitivity in lambs with IUGR but not persistent defects in pancreatic islets or skeletal muscle

      Yates, Dustin T; Camacho, Leticia E; Kelly, Amy C; Steyn, Leah V; Davis, Melissa A; Antolic, Andrew T; Anderson, Miranda J; Goyal, Ravi; Allen, Ronald E; Papas, Klearchos K; et al. (WILEY, 2019-10-30)
      Placental insufficiency causes intrauterine growth restriction (IUGR) and disturbances in glucose homeostasis with associated β adrenergic receptor (ADRβ) desensitization. Our objectives were to measure insulin‐sensitive glucose metabolism in neonatal lambs with IUGR and to determine whether daily treatment with ADRβ2 agonist and ADRβ1/β3 antagonists for 1 month normalizes their glucose metabolism. Growth, glucose‐stimulated insulin secretion (GSIS) and glucose utilization rates (GURs) were measured in control lambs, IUGR lambs and IUGR lambs treated with adrenergic receptor modifiers: clenbuterol atenolol and SR59230A (IUGR‐AR). In IUGR lambs, islet insulin content and GSIS were less than in controls; however, insulin sensitivity and whole‐body GUR were not different from controls. Of importance, ADRβ2 stimulation with β1/β3 inhibition increases both insulin sensitivity and whole‐body glucose utilization in IUGR lambs. In IUGR and IUGR‐AR lambs, hindlimb GURs were greater but fractional glucose oxidation rates and ex vivo skeletal muscle glucose oxidation rates were lower than controls. Glucose transporter 4 (GLUT4) was lower in IUGR and IUGR‐AR skeletal muscle than in controls but GLUT1 was greater in IUGR‐AR. ADRβ2, insulin receptor, glycogen content and citrate synthase activity were similar among groups. In IUGR and IUGR‐AR lambs heart rates were greater, which was independent of cardiac ADRβ1 activation. We conclude that targeted ADRβ2 stimulation improved whole‐body insulin sensitivity but minimally affected defects in GSIS and skeletal muscle glucose oxidation. We show that risk factors for developing diabetes are independent of postnatal catch‐up growth in IUGR lambs as early as 1 month of age and are inherent to the islets and myocytes.
    • Postoperative chemoradiotherapy versus radiotherapy alone for elderly cervical cancer patients with positive margins, lymph nodes, or parametrial invasion

      Cushman, Taylor R; Haque, Waqar; Menon, Hari; Rusthoven, Chad G; Butler, E Brian; Teh, Bin S; Verma, Vivek; Univ Arizona, Coll Med Phoenix (KOREAN SOC GYNECOLOGY ONCOLOGY & COLPOSCOPY, 2018-11-01)
      Women with cervical cancer (CC) found to have positive surgical margins, positive lymph nodes, and/or parametrial invasion receive a survival benefit from postoperative chemoradiotherapy (CRT) vs. radiation therapy (RT) alone. However, older women may not benefit to the same extent, as they are at increased risk of death from non-oncologic causes as well as toxicities from oncologic treatments. This study sought to evaluate whether there was a survival benefit of CRT over RT in elderly patients with cervical cancer. Methods: The National Cancer Database was queried for patients >= 70 years old with newly diagnosed IA2, IB, or IIA CC and positive margins, parametrial invasion, and/or positive nodes on surgical resection. Statistics included logistic regression, Kaplan-Meier overall survival (OS), and Cox proportional hazards modeling analyses. Results: Altogether, 166 patients met inclusion criteria; 62 (37%) underwent postoperative RT and 104 (63%) underwent postoperative CRT. Younger patients and those living in areas of higher income were less likely to receive CRT, while parametrial invasion and nodal involvement were associated with an increased likelihood (p<0.05 for all). There were no OS differences by treatment type. Subgroup analysis by number of risk factors, as well as each of the 3 risk factors separately, also did not reveal any OS differences between cohorts. Conclusion: In the largest such study to date, older women with postoperative risk factor(s) receiving RT alone experienced similar survival as those undergoing CRT. Although causation is not implied, careful patient selection is paramount to balance treatment-related toxicity risks with theoretical outcome benefits.
    • Postpartum Changes in Mood and Smoking-Related Symptomatology: An Ecological Momentary Assessment Investigation

      Allen, Alicia; Tosun, Nicole; Carlson, Samantha; Allen, Sharon; Univ Arizona, Dept Family & Community Med (OXFORD UNIV PRESS, 2018-06)
      Introduction: Postpartum smoking relapse is a highly prevalent public health problem. Mood and breast feeding are significantly associated with smoking relapse, although less is known about the temporality of these relationships. Therefore, this study utilized ecological momentary assessments (EMA) to prospectively examine changes in mood and smoking-related symptomatology in relationship to three events-childbirth, termination of breast feeding, and smoking relapse. We expected all three events to significantly alter mood and smoking-related symptomatology. Methods: We enrolled a sample of pregnant women who had recently quit smoking and intended to remain quit during the postpartum. Participants were randomized to active/placebo progesterone to prevent postpartum relapse. Participants also completed daily EMA to collect data mood and smoking-related symptomatology as well as our three events of interest. Results: Participants (n = 46) were, on average, 26.5 +/- 0.8 years old and, prior to pregnancy, smoked 10.1 +/- 0.7 cigarettes/day. We noted a number of significant within-and between-subject relationships. For example, participants reported a 24% decline in negative affect after childbirth (p = .0016). Among those who relapsed to smoking (n = 23), participants randomized to placebo had a significant increase in cigarette craving after relapse (beta = 1.06, 95% confidence interval [CI] = 0.62 to 1.49, p value = .0003), whereas participants randomized to active progesterone did not (beta = 0.63, 95% CI = -0.35 to 1.62, p value = .1824). Conclusions: These observations suggest that mood and smoking-related symptomatology are influenced by childbirth, breast feeding, smoking relapse, and use of exogenous progesterone. Future research should explore how these observations may inform novel postpartum smoking relapse-prevention interventions.
    • Postwildfire Soil-Hydraulic Recovery and the Persistence of Debris Flow Hazards

      Thomas, M.A.; Rengers, F.K.; Kean, J.W.; McGuire, L.A.; Staley, D.M.; Barnhart, K.R.; Ebel, B.A.; Department of Geosciences, Unviersity of Arizona (Blackwell Publishing Ltd, 2021)
      Deadly and destructive debris flows often follow wildfire, but understanding of changes in the hazard potential with time since fire is poor. We develop a simulation-based framework to quantify changes in the hydrologic triggering conditions for debris flows as postwildfire infiltration properties evolve through time. Our approach produces time-varying rainfall intensity-duration thresholds for runoff- and infiltration-generated debris flows with physics-based hydrologic simulations that are parameterized with widely available hydroclimatic, vegetation reflectance, and soil texture data. When we apply our thresholding protocol to a test case in the San Gabriel Mountains (California, USA), the results are consistent with existing regional empirical thresholds and rainstorms that caused runoff- and infiltration-generated debris flows soon after and three years following a wildfire, respectively. We find that the hydrologic triggering mechanisms for the two observed debris flow types are coupled with the effects of fire on the soil saturated hydraulic conductivity. Specifically, the rainfall intensity needed to generate debris flows via runoff increases with time following wildfire while the rainfall duration needed to produce debris flows via subsurface pore-water pressures decreases. We also find that variations in soil moisture, rainfall climatology, median grain size, and root reinforcement could impact the median annual probability of postwildfire debris flows. We conclude that a simulation-based method for calculating rainfall thresholds is a tractable approach to improve situational awareness of debris flow hazard in the years following wildfire. Further development of our framework will be important to quantify postwildfire hazard levels in variable climates, vegetation types, and fire regimes. © 2021. The Authors. Journal of Geophysical Research: Earth Surface published by Wiley Periodicals LLC on behalf of American Geophysical Union. This article has been contributed to by US Government employees and their work is in the public domain in the USA.
    • Potassium tune-out-wavelength measurement using atom interferometry and a multipass optical cavity

      Trubko, Raisa; Gregoire, Maxwell D.; Holmgren, William F.; Cronin, Alexander D.; Univ Arizona, Coll Opt Sci; Univ Arizona, Dept Phys (AMER PHYSICAL SOC, 2017-05-26)
      The longest tune-out wavelength for potassium atoms, lambda(zero) = 768.9701(4) nm, was measured using an atom interferometer with a large irradiance gradient supported in a multipass optical cavity. Systematic errors in lambda(zero) measurements that arise from laser light, Doppler shifts, and the Earth's rotation are described. The ratio of oscillator strengths for the potassium D2 and D1 lines inferred from this lambda(zero) measurement is rho = f(D2)/f(D1) = 2.0066(11), and the ratio of line strengths is R = S-D2/S-D1 = 1.9977(11).
    • Potential bioavailability of organic matter from atmospheric particles to marine heterotrophic bacteria

      Djaoudi, K.; Van, Wambeke, F.; Barani, A.; Bhairy, N.; Chevaillier, S.; Desboeufs, K.; Nunige, S.; Labiadh, M.; Henry, Des, Tureaux, T.; Lefèvre, D.; et al. (Copernicus GmbH, 2020)
      The surface ocean receives important amounts of organic carbon from atmospheric deposition. The degree of bioavailability of this source of organic carbon will determine its impact on the marine carbon cycle. In this study, the potential availability of dissolved organic carbon (DOC) leached from both desert dust and anthropogenic aerosols to marine heterotrophic bacteria was investigated. The experimental design was based on 16 d incubations, in the dark, of a marine bacterial inoculum into artificial seawater amended with water-soluble Saharan dust (D treatment) and anthropogenic (A treatment) aerosols, so that the initial DOC concentration was similar between treatments. Glucose-amended (G) and non-amended (control) treatments were run in parallel. Over the incubation period, an increase in bacterial abundance (BA) and bacterial production (BP) was observed first in the G treatment, followed then by the D and finally A treatments, with bacterial growth rates significantly higher in the G and D treatments than the A treatment. Following this growth, maxima of BP reached were similar in the D (879 ± 64 ng C L-1 h-1; n = 3) and G (648 ± 156 ng C L-1 h-1; n = 3) treatments and were significantly higher than in the A treatment (124 ng C L-1 h-1; n = 2). The DOC consumed over the incubation period was similar in the A (9 μM; n = 2) and = (9 ± 2 μM; n = 3) treatments and was significantly lower than in the G treatment (22 ± 3 μM; n = 3). Nevertheless, the bacterial growth efficiency (BGE) in the = treatment (14.2 ± 5.5 %; n = 3) compared well with the G treatment (7.6 ± 2 %; n = 3), suggesting that the metabolic use of the labile DOC fraction in both conditions was energetically equivalent. In contrast, the BGE in the A treatment was lower (1.7 %; n = 2), suggesting that most of the used labile DOC was catabolized. The results obtained in this study highlight the potential of aerosol organic matter to sustain the metabolism of marine heterotrophs and stress the need to include this external source of organic carbon in biogeochemical models for a better constraining of the carbon budget. © 2020 Author(s).
    • Potential evidence for epigenetic biomarkers of metabolic syndrome in human whole blood in Latinos

      Urashima, K.; Miramontes, A.; Garcia, L.A.; Coletta, D.K.; Department of Physiology, University of Arizona; Department of Medicine, Division of Endocrinology, University of Arizona; Center for Disparities in Diabetes Obesity, and Metabolism, University of Arizona (Public Library of Science, 2021)
      Metabolic syndrome (MetS) is highly prevalent worldwide. In the United States, estimates show that more than 30% of the adult population has MetS. MetS consists of multiple phenotypes, including obesity, dyslipidemia, and impaired glucose tolerance. Therefore, identifying the molecular mechanisms to explain this complex disease is critical for diagnosing and treating MetS. We previously showed 70 increased genes and 20 decreased genes in whole blood in MetS participants. The present study aimed to identify blood-based DNA methylation biomarkers in non-MetS versus MetS participants. The present study analyzed whole blood DNA samples from 184 adult participants of Latino descent from the Arizona Insulin Resistance (AIR) registry. We used the National Cholesterol Education Program Adult Treatment Panel III (NCEP: ATP III) criteria to identify non-MetS (n = 110) and MetS (n = 74) participants. We performed whole blood methylation analysis on select genes: ATP Synthase, H+ Transporting mitochondrial F1 Complex, Epsilon Subunit (ATP5E), Cytochrome C Oxidase Subunit VIc (COX6C), and Ribosomal Protein L9 (RPL9). The pyrosequencing analysis was a targeted approach focusing on the promoter region of each gene that specifically captured CpG methylation sites. In MetS participants, we showed decreased methylation in two CpG sites in COX6C and three CpG sites in RPL9, all p < 0.05 using the Mann-Whitney U test. There were no ATP5E CpG sites differently methylated in the MetS participants. Furthermore, while adjusting for age, gender, and smoking status, logistic regression analysis reaffirmed the associations between MetS and mean methylation within COX6C and RPL9 (both p < 0.05). In addition, Spearman’s correlation revealed a significant inverse relationship between the previously published gene expression data and methylation data for RPL9 (p < 0.05). In summary, these results highlight potential blood DNA methylation biomarkers for the MetS phenotype. However, future validation studies are warranted to strengthen our findings. Copyright: © 2021 Urashima et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
    • Potential life-years gained over a 5-year period by correcting DOPPS-identified modifiable practices in haemodialysis: results from the European MONITOR-CKD5 study

      Combe, Christian; Mann, Johannes; Goldsmith, David; Dellanna, Frank; Zaoui, Philippe; London, Gérard; Denhaerynck, Kris; Krendyukov, Andriy; Abraham, Ivo; MacDonald, Karen; et al. (BMC, 2019-03-05)
      BackgroundDOPPS reported that thousands of life-years could be gained in the US and Europe over 5years by correcting six modifiable haemodialysis practices. We estimated potential life-years gained across 10 European countries using MONITOR-CKD5 study data.MethodsThe DOPPS-based target ranges were used, except for haemoglobin due to label changes, as well as DOPPS-derived relative mortality risks. Percentages of MONITOR-CKD5 patients outside targets were calculated. Consistent with the DOPPS-based analyses, we extrapolated life-years gained for the MONITOR-CKD5 population over 5years if all patients were within targets.ResultsBringing the 10 MONITOR-CKD5 countries' dialysis populations into compliance on the six practices results in a 5-year gain of 97,428 patient-years. In descending order, survival impact was the highest for albumin levels, followed by phosphate levels, vascular access, haemoglobin, dialysis adequacy, and interdialytic weight gain.ConclusionsOptimal management of the six modifiable haemodialysis practices may achieve 6.2% increase in 5-year survival.Trial RegistrationNCT01121237. registration May 12, 2010 (retrospectively registered).
    • Potential limits to the benefits of admixture during biological invasion

      Barker, Brittany S; Cocio, Janelle E; Anderson, Samantha R; Braasch, Joseph E; Cang, Feng A; Gillette, Heather D; Dlugosch, Katrina M; Univ Arizona (WILEY, 2019-01-01)
      Species introductions often bring together genetically divergent source populations, resulting in genetic admixture. This geographic reshuffling of diversity has the potential to generate favourable new genetic combinations, facilitating the establishment and invasive spread of introduced populations. Observational support for the superior performance of admixed introductions has been mixed, however, and the broad importance of admixture to invasion questioned. Under most underlying mechanisms, admixture's benefits should be expected to increase with greater divergence among and lower genetic diversity within source populations, though these effects have not been quantified in invaders. We experimentally crossed source populations differing in divergence in the invasive plant Centaurea solstitialis. Crosses resulted in many positive (heterotic) interactions, but fitness benefits declined and were ultimately negative at high source divergence, with patterns suggesting cytonuclear epistasis. We explored the literature to assess whether such negative epistatic interactions might be impeding admixture at high source population divergence. Admixed introductions reported for plants came from sources with a wide range of genetic variation, but were disproportionately absent where there was high genetic divergence among native populations. We conclude that while admixture is common in species introductions and often happens under conditions expected to be beneficial to invaders, these conditions may be constrained by predictable negative genetic interactions, potentially explaining conflicting evidence for admixture's benefits to invasion.
    • Potential of Hydraulic Tomography in Identifying Boundary Conditions of Groundwater Basins

      Liu, F.; Yeh, T.-C.J.; Wang, Y.-L.; Song, X.; Lei, X.; Wen, J.-C.; Wang, W.; Hao, Y.; University of Arizona (Blackwell Publishing Ltd, 2020)
      This study investigates the potential of hydraulic tomography (HT) in identifying the boundary conditions of groundwater basins using numerical experiments. The experiment mimics the scenario of groundwater exploitation reduction in a pilot area of groundwater overexploitation control in the North China Plain. In this study, we propose an approach that integrates the HT concept and readily available groundwater monitoring data to identify the constant head and impermeable boundaries by mapping anomalously high- and low-permeability zones from HT surveys in a large-scale domain that encompasses the true groundwater basin. The resulting boundaries and conditions were then used in inversion of steady-state and transient-state simultaneous pumping tests and HT surveys of heterogeneity within the groundwater basin. The inversion results demonstrated significant advantages of HT surveys over multiple simultaneous pumping tests to identify boundary conditions and heterogeneity in the groundwater basin. Moreover, steady HT inversion outperforms transient HT inversion in capturing the true boundary conditions, leading to the better T estimates from steady HT inversion than those from transient HT inversion. Additionally, the study shows that accurate geological zonation information can significantly improve HT parameter estimations. ©2020. American Geophysical Union. All Rights Reserved.
    • Potential of small culverts as wildlife passages on forest roads

      Chen, H.-L.; Posthumus, E.E.; Koprowski, J.L.; School of Natural Resources and the Environment, University of Arizona (MDPI AG, 2021)
      Roads and traffic can cause animal mortality. Specifically, roads serve as barriers by im-peding animal movement, resulting in demographic and genetic consequences. Drainage structures, such as culverts, can provide linkages between habitat patches. However, the potential of small culverts with diameters of <60 cm (e.g., wildlife passages that facilitate movement on forest roads) are relatively unknown. In this study, we used trail cameras to monitor the use of 14 small culverts, by mammals, along forest roads on Mt. Graham, home of the critically endangered Mt. Graham red squirrels (Tamiasciurus hudsonicus grahamensis), in southeastern Arizona, USA. From 2011 to 2013, we only recorded 20 completed road crossings through culverts. More than half of culvert uses were by striped skunks (Mephitis mephitis), followed by the rock squirrel (Spermophilus variegatus) and the bobcat (Lynx rufus). The Mt. Graham red squirrel was the only species that was common along the roads, but never crossed the roads. Culverts with higher usages were characterized by shorter culvert lengths and absence of accumulated soil inside the culverts. Our study shows that small-dimension drainage systems may provide alternative pathways for wildlife crossing roads, especially for slow moving and ground dwelling species. However, the potential of small culverts assisting wildlife crossings can only be maximized when culverts are accessible year-round. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
    • Potential perils of peri-Pokémon perambulation: the dark reality of augmented reality?

      Joseph, Bellal; Armstrong, David G.; Univ Arizona, Dept Surg, Div Trauma Crit Care & Emergency Surg (OXFORD UNIV PRESS, 2016-10-05)
      Recently, the layering of augmented reality information on top of smartphone applications has created unprecedented user engagement and popularity. One augmented reality-based entertainment application, Pokemon Go (Pokemon Company, Tokyo, Japan) has become the most rapidly downloaded in history. This technology holds tremendous promise to promote ambulatory activity. However, there exists the obvious potential for distraction-related morbidity. We report two cases, presenting simultaneously to our trauma center, with injuries sustained secondary to gameplay with this augmented reality-based application.
    • Potential uses of Numerical Simulation for the Modelling of Civil Conflict

      Burton, Lucy; Johnson, Shane D.; Braithwaite, Alex; Univ Arizona, Sch Govt & Publ Policy (WALTER DE GRUYTER GMBH, 2017-01-01)
      This paper explores ways in which civil conflict can be simulated using numerical methods. A general two-party model of conflict is developed by extending an approach proposed by [Christia, F., (2012), Alliance Formation in Civil Wars, Cambridge University Press, New York], which is based on a metric of the 'relative power' that exists between the state and a rebel group. Various definitions of relative power are considered and one of these is chosen to illustrate different types of two-sided armed conflict, namely direct-fire, guerrilla and asymmetric warfare. The additional suggestion of Christia that random or stochastic events can lead to unexpected conflict outcomes is also further extended in this paper. The inclusion in the model of terms describing concurrent rebel recruitment of civilians and state deployment of troops are then described. Examples are presented for various hypothetical cases. It is demonstrated that numerical simulation techniques have great potential for modelling civil war. The Christia approach is shown to provide an excellent basis from which numerical models of civil conflict can be built and from which the progress of a conflict can usefully be visualised graphically.
    • Power counting in peripheral partial waves: The singlet channels

      Valderrama, M. Pavon; Sanchez, M. Sanchez; Yang, C.-J.; Long, Bingwei; Carbonell, J.; van Kolck, U.; Univ Arizona, Dept Phys (AMER PHYSICAL SOC, 2017-05-10)
      We analyze the power counting of the peripheral singlet partial waves in nucleon-nucleon scattering. In agreement with conventional wisdom, we find that pion exchanges are perturbative in the peripheral singlets. We quantify from the effective field theory perspective the well-known suppression induced by the centrifugal barrier in the pion-exchange interactions. By exploring perturbation theory up to fourth order, we find that the one-pion-exchange potential in these channels is demoted from leading to subleading order by a given power of the expansion parameter that grows with the orbital angular momentum. We discuss the implications of these demotions for few-body calculations: though higher partialwaves have been known for a long time to be irrelevant in these calculations (and are hence ignored), here we explain how to systematize the procedure in a way that is compatible with the effective field theory expansion.
    • Power difference in a χ2 test vs generalized linear mixed model in the presence of missing data – a simulation study

      Miller, Mary L; Roe, Denise J; Hu, Chengcheng; Bell, Melanie L; Univ Arizona, Dept Epidemiol & Biostat (BMC, 2020-03-02)
      Longitudinal randomized controlled trials (RCTs) often aim to test and measure the effect of treatment between arms at a single time point. A two-sample χ2 test is a common statistical approach when outcome data are binary. However, only complete outcomes are used in the analysis. Missing responses are common in longitudinal RCTs and by only analyzing complete data, power may be reduced and estimates could be biased. Generalized linear mixed models (GLMM) with a random intercept can be used to test and estimate the treatment effect, which may increase power and reduce bias.
    • Power scalable 10  W 976  nm single-frequency linearly polarized laser source

      Wu, Jingwei; Zhu, Xiushan; Wei, Hua; Wiersma, Kort; Li, Michael; Zong, Jie; Chavez-Pirson, Arturo; Temyanko, Valery; LaComb, L. J.; Norwood, R. A.; et al. (OPTICAL SOC AMER, 2018-02-15)
      A 10 W level 976 nm single-frequency linearly polarized laser source was demonstrated with a two-stage all-fiber amplifier configuration. The continuous-wave output power of 10.1 W was obtained from the second stage amplifier by using a 20/130 mu m single-mode, polarization maintaining, 1.5 wt. % ytterbium-doped phosphate double-clad fiber. This all-fiber single-frequency laser source is very promising for watt-level deep ultraviolet laser generation via frequency quadrupling. (C) 2018 Optical Society of America