• Detection of CH3C3N in Titan’s Atmosphere

  Thelen, Alexander E.; Cordiner, Martin A.; Nixon, Conor A.; Vuitton, Véronique; Kisiel, Zbigniew; Charnley, Steven B.; Palmer, Maureen Y.; Teanby, Nicholas A.; Irwin, Patrick G. J.; Univ Arizona, Lunar & Planetary Lab (IOP PUBLISHING LTD, 2020-11-02)

  Titan harbors a dense, organic-rich atmosphere primarily composed of N-2 and CH4, with lesser amounts of hydrocarbons and nitrogen-bearing species. As a result of high-sensitivity observations by the Atacama Large Millimeter/submillimeter Array (ALMA) in Band 6 (similar to 230-272 GHz), we obtained the first spectroscopic detection of CH3C3N (methylcyanoacetylene or cyanopropyne) in Titan's atmosphere through the observation of seven transitions in the J = 64 -> 63 and J = 62 -> 61 rotational bands. The presence of CH3C3N on Titan was suggested by the Cassini Ion and Neutral Mass Spectrometer detection of its protonated form: C4H3NH+, but the atmospheric abundance of the associated (deprotonated) neutral product is not well constrained due to the lack of appropriate laboratory reaction data. Here, we derive the column density of CH3C3N to be (3.8-5.7).x.10(12) cm(-2) based on radiative transfer models sensitive to altitudes above 400 km Titan's middle atmosphere. When compared with laboratory and photochemical model results, the detection of methylcyanoacetylene provides important constraints for the determination of the associated production pathways (such as those involving CN, CCN, and hydrocarbons), and reaction rate coefficients. These results also further demonstrate the importance of ALMA and (sub)millimeter spectroscopy for future investigations of Titan's organic inventory and atmospheric chemistry, as CH3C3N marks the heaviest polar molecule detected spectroscopically in Titan's atmosphere to date.
• Validation of a brief scale to assess ambulatory patients' perceptions of reading visit notes: a scale development study

  Wright, Julie A; Leveille, Suzanne G; Chimowitz, Hannah; Fossa, Alan; Stametz, Rebecca; Clarke, Deserae; Walker, Jan; Univ Arizona, Coll Med, Clin Data Analyt & Decis Support (BMJ PUBLISHING GROUP, 2020-10-20)

  Study 1 resulted in the selection of a 10-point importance response option format over a 4-point agreement scale. Exploratory factor analysis (EFA) in study 2 resulted in two-factor solution: a four-item benefits factor with good reliability (alpha=0.83) and a three-item risks factor with poor reliability (alpha=0.52). The factor structure was confirmed in study 3, and confirmatory factor analysis of benefit items resulted in an excellent fitting model, X2(2)=2.949; confirmatory factor index=0.998; root mean square error of approximation=0.04 (0.00, 0.142); loadings 0.68-0.86; alpha=0.88. Study 4 supported configural, measurement and structural invariance for the benefits scale across high and low-education patient groups.
• Dependence of the IRX-β Dust Attenuation Relation on Metallicity and Environment

  Shivaei, Irene; Darvish, Behnam; Sattari, Zahra; Chartab, Nima; Mobasher, Bahram; Scoville, Nick; Rieke, George; Univ Arizona, Steward Observ (IOP PUBLISHING LTD, 2020-11-05)

  We use a sample of star-forming field and protocluster galaxies at z.=.2.0-2.5 with Keck/MOSFIRE K-band spectra, a wealth of rest-frame ultraviolet (UV) photometry, and Spitzer/MIPS and Herschel/PACS observations, to dissect the relation between the ratio of infrared (IR) to UV luminosity (IRX) versus UV slope (beta) as a function of gas-phase metallicity (12 + log(O H) similar to 8.2-8.7). We find no significant dependence of the IRX-beta trend on environment. However, we find that at a given beta, IRX is highly correlated with metallicity, and less correlated with mass, age, and specific star formation rate (sSFR). We conclude that, of the physical properties tested here, metallicity is the primary physical cause of the IRX-beta scatter, and the IRX correlation with mass is presumably due to the mass dependence on metallicity. Our results indicate that the UV attenuation curve steepens with decreasing metallicity, and spans the full range of slope possibilities from a shallow Calzetti-type curve for galaxies with the highest metallicity in our sample (12 + log(O H) similar to 8.6) to a steep Small Magellanic Cloud (SMC)-like curve for those with 12 + log(O H)similar to 8.3. Using a Calzetti (SMC) curve for the low (high) metallicity galaxies can lead to up to a factor of 3 overestimation (underestimation) of the UV attenuation and obscured star formation rate. We speculate that this change is due to different properties of dust grains present in the interstellar medium of low- and high-metallicity galaxies.
• Tranexamic Acid During Prehospital Transport in Patients at Risk for Hemorrhage After Injury: A Double-blind, Placebo-Controlled, Randomized Clinical Trial

  Guyette, Francis X; Brown, Joshua B; Zenati, Mazen S; Early-Young, Barbara J; Adams, Peter W; Eastridge, Brian J; Nirula, Raminder; Vercruysse, Gary A; O'Keeffe, Terence; Joseph, Bellal; et al. (AMER MEDICAL ASSOC, 2020-10-05)

  Importance In-hospital administration of tranexamic acid after injury improves outcomes in patients at risk for hemorrhage. Data demonstrating the benefit and safety of the pragmatic use of tranexamic acid in the prehospital phase of care are lacking for these patients. Objective To assess the effectiveness and safety of tranexamic acid administered before hospitalization compared with placebo in injured patients at risk for hemorrhage. Design, Setting, and Participants This pragmatic, phase 3, multicenter, double-blind, placebo-controlled, superiority randomized clinical trial included injured patients with prehospital hypotension (systolic blood pressure <= 90 mm Hg) or tachycardia (heart rate >= 110/min) before arrival at 1 of 4 US level 1 trauma centers, within an estimated 2 hours of injury, from May 1, 2015, through October 31, 2019. Interventions Patients received 1 g of tranexamic acid before hospitalization (447 patients) or placebo (456 patients) infused for 10 minutes in 100 mL of saline. The randomization scheme used prehospital and in-hospital phase assignments, and patients administered tranexamic acid were allocated to abbreviated, standard, and repeat bolus dosing regimens on trauma center arrival. Main Outcomes and Measures The primary outcome was 30-day all-cause mortality. Results In all, 927 patients (mean [SD] age, 42 [18] years; 686 [74.0%] male) were eligible for prehospital enrollment (460 randomized to tranexamic acid intervention; 467 to placebo intervention). After exclusions, the intention-to-treat study cohort comprised 903 patients: 447 in the tranexamic acid arm and 456 in the placebo arm. Mortality at 30 days was 8.1% in patients receiving tranexamic acid compared with 9.9% in patients receiving placebo (difference, -1.8%; 95% CI, -5.6% to 1.9%;P = .17). Results of Cox proportional hazards regression analysis, accounting for site, verified that randomization to tranexamic acid was not associated with a significant reduction in 30-day mortality (hazard ratio, 0.81; 95% CI, 0.59-1.11,P = .18). Prespecified dosing regimens and post-hoc subgroup analyses found that prehospital tranexamic acid were associated with significantly lower 30-day mortality. When comparing tranexamic acid effect stratified by time to treatment and qualifying shock severity in a post hoc comparison, 30-day mortality was lower when tranexamic acid was administered within 1 hour of injury (4.6% vs 7.6%; difference, -3.0%; 95% CI, -5.7% to -0.3%;P < .002). Patients with severe shock (systolic blood pressure <= 70 mm Hg) who received tranexamic acid demonstrated lower 30-day mortality compared with placebo (18.5% vs 35.5%; difference, -17%; 95% CI, -25.8% to -8.1%;P < .003). Conclusions and Relevance In injured patients at risk for hemorrhage, tranexamic acid administered before hospitalization did not result in significantly lower 30-day mortality. The prehospital administration of tranexamic acid after injury did not result in a higher incidence of thrombotic complications or adverse events. Tranexamic acid given to injured patients at risk for hemorrhage in the prehospital setting is safe and associated with survival benefit in specific subgroups of patients.
• Neo-racism and the Criminalization of China

  Lee, Jenny; Univ Arizona, Ctr Study Higher Educ (UNIV LOUISIANA MONROE, 2020-11-15)

View more