274 results on '"Black RA"'
Search Results
2. The Genome of the 'Great Speciator' Provides Insights into Bird Diversification
- Author
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Savolainen, V, Cornetti, L, Valente, LM, Dunning, LT, Quan, X, Black, RA, and Hebert, O
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Genome evolution ,demography ,Genome ,Zosterops lateralis ,Genetic Speciation ,gene duplication ,Zoology ,phylogenomics ,Biology ,Subspecies ,genome evolution ,biology.organism_classification ,Zosterops ,Sympatric speciation ,positive selection ,Phylogenomics ,Genetics ,Animals ,Taxonomic rank ,Passeriformes ,morphological divergence ,Institut für Biochemie und Biologie ,Ecology, Evolution, Behavior and Systematics ,Research Article - Abstract
Among birds, white-eyes (genus Zosterops) have diversified so extensively that Jared Diamond and Ernst Mayr referred to them as the "great speciator." The Zosterops lineage exhibits some of the fastest rates of species diversification among vertebrates, and its members are the most prolific passerine island colonizers. We present a high-quality genome assembly for the silvereye (Zosterops lateralis), a white-eye species consisting of several subspecies distributed across multiple islands. We investigate the genetic basis of rapid diversification in white-eyes by conducting genomic analyses at varying taxonomic levels. First, we compare the silvereye genome with those of birds from different families and searched for genomic features that may be unique to Zosterops. Second, we compare the genomes of different species of white-eyes from Lifou island (South Pacific), using whole genome resequencing and restriction site associated DNA. Third, we contrast the genomes of two subspecies of silvereye that differ in plumage color. In accordance with theory, we show that white-eyes have high rates of substitutions, gene duplication, and positive selection relative to other birds. Below genus level, we find that genomic differentiation accumulates rapidly and reveals contrasting demographic histories between sympatric species on Lifou, indicative of past interspecific interactions. Finally, we highlight genes possibly involved in color polymorphism between the subspecies of silvereye. By providing the first whole-genome sequence resources for white-eyes and by conducting analyses at different taxonomic levels, we provide genomic evidence underpinning this extraordinary bird radiation.
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- 2015
3. Determination of the nu(e) and total B-8 solar neutrino fluxes using the Sudbury Neutrino Observatory Phase I data set
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Aharmim, B, Ahmad, QR, Ahmed, SN, Allen, RC, Andersen, TC, Anglin, JD, Buehler, G, Barton, JC, Beier, EW, Bercovitch, M, Bergevin, M, Bigu, J, Biller, SD, Black, RA, Blevis, I, Boardman, RJ, Boger, J, Bonvin, E, Boulay, MG, Bowler, MG, Bowles, TJ, Brice, SJ, Browne, MC, Bullard, TV, Burritt, TH, Cameron, J, Chan, YD, Chen, HH, Chen, M, Chen, X, Cleveland, BT, Cowan, JHM, Cowen, DF, Cox, GA, Currat, CA, Dai, X, Dalnoki-Veress, F, Davidson, WF, Deng, H, DiMarco, M, Doe, PJ, Doucas, G, Dragowsky, MR, Duba, CA, Duncan, FA, Dunford, M, Dunmore, JA, Earle, ED, Elliott, SR, Evans, HC, Ewan, GT, Farine, J, Fergani, H, Ferraris, AP, Fleurot, F, Ford, RJ, Formaggio, JA, Fowler, MM, Frame, K, Frank, ED, Frati, W, Gagnon, N, Germani, JV, Gil, S, Goldschmidt, A, Goon, JTM, Graham, K, Grant, DR, Guillian, E, Hahn, RL, Hallin, AL, Hallman, ED, Hamer, AS, Hamian, AA, Handler, WB, Haq, RU, Hargrove, CK, Harvey, PJ, Hazama, R, Heeger, KM, Heintzelman, WJ, Heise, J, Helmer, RL, Henning, R, Hepburn, JD, Heron, H, Hewett, J, Hime, A, Howard, C, Howe, MA, Huang, M, Hykaway, JG, Isaac, MCP, Jagam, P, Jamieson, B, Jelley, NA, Jillings, C, Jonkmans, G, Kazkaz, K, Keener, PT, Kirch, K, Klein, JR, Knox, AB, Komar, RJ, Kormos, LL, Kos, M, Kouzes, R, Krueger, A, Kraus, C, Krauss, CB, Kutter, T, Kyba, CCM, Labranche, H, Lange, R, Law, J, Lawson, IT, Lay, M, Lee, HW, Lesko, KT, Leslie, JR, Levine, I, Loach, JC, Locke, W, Luoma, S, Lyon, J, MacLellan, R, Majerus, S, Mak, HB, Maneira, J, Marino, AD, Martin, R, McCauley, N, McDonald, AB, McDonald, DS, McFarlane, K, McGee, S, McGregor, G, Drees, RM, Mes, H, Mifflin, C, Miknaitis, KKS, Miller, ML, Milton, G, Moffat, BA, Monreal, B, Moorhead, M, Morrissette, B, Nally, CW, Neubauer, MS, Newcomer, FM, Ng, HS, Nickel, BG, Noble, AJ, Norman, EB, Novikov, VM, Oblath, NS, Okada, CE, O'Keeffe, HM, Ollerhead, RW, Omori, M, Orrell, JL, Oser, SM, Ott, R, Peeters, SJM, Poon, AWP, Prior, G, Reitzner, SD, Rielage, K, Roberge, A, Robertson, BC, Robertson, RGH, Rosendahl, SSE, Rowley, JK, Rusu, VL, Saettler, E, Schulke, A, Schwendener, MH, Secrest, JA, Seifert, H, Shatkay, M, Simpson, JJ, Sims, CJ, Sinclair, D, Skensved, P, Smith, AR, Smith, MWE, Starinsky, N, Steiger, TD, Stokstad, RG, Stonehill, LC, Storey, RS, Sur, B, Tafirout, R, Tagg, N, Takeuchi, Y, Tanner, NW, Taplin, RK, Thorman, M, Thornewell, PM, Tolich, N, Trent, PT, Tserkovnyak, YI, Tsui, T, Tunnell, CD, Van Berg, R, De Water, RGV, Virtue, CJ, Walker, TJ, Wall, BL, Waltham, CE, Tseung, HWC, Wang, J-X, Wark, DL, Wendland, J, West, N, Wilhelmy, JB, Wilkerson, JF, Wilson, JR, Wittich, P, Wouters, JM, Wright, A, Yeh, M, Zuber, K, and Collaboration, SNO
- Published
- 2007
4. Measurement of the rate of nu(e) + d --p + p + e(-) interactions produced by (8)B solar neutrinos at the Sudbury Neutrino Observatory
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Ahmad, QR, Allen, RC, Andersen, TC, Anglin, JD, Bühler, G, Barton, JC, Beier, EW, Bercovitch, M, Bigu, J, Biller, S, Black, RA, Blevis, I, Boardman, RJ, Boger, J, Bonvin, E, Boulay, MG, Bowler, MG, Bowles, TJ, Brice, SJ, Browne, MC, Bullard, TV, Burritt, TH, Cameron, K, Cameron, J, Chan, YD, Chen, M, Chen, HH, Chen, X, Chon, MC, Cleveland, BT, Clifford, ET, Cowan, JH, Cowen, DF, Cox, GA, Dai, Y, Dai, X, Dalnoki-Veress, F, Davidson, WF, Doe, PJ, Doucas, G, Dragowsky, MR, Duba, CA, Duncan, FA, Dunmore, J, Earle, ED, Elliott, SR, Evans, HC, Ewan, GT, Farine, J, Fergani, H, Ferraris, AP, Ford, RJ, Fowler, MM, Frame, K, Frank, ED, Frati, W, Germani, JV, Gil, S, Goldschmidt, A, Grant, DR, Hahn, RL, Hallin, AL, Hallman, ED, Hamer, A, Hamian, AA, Haq, RU, Hargrove, CK, Harvey, PJ, Hazama, R, Heaton, R, Heeger, KM, Heintzelman, WJ, Heise, J, Helmer, RL, Hepburn, JD, Heron, H, Hewett, J, Hime, A, Howe, M, Hykawy, JG, Isaac, MC, Jagam, P, Jelley, NA, Jillings, C, Jonkmans, G, Karn, J, Keener, PT, Kirch, K, Klein, JR, Knox, AB, Komar, RJ, Kouzes, R, Kutter, T, Kyba, CC, Law, J, Lawson, IT, Lay, M, Lee, HW, Lesko, KT, Leslie, JR, Levine, I, Locke, W, Lowry, MM, Luoma, S, Lyon, J, Majerus, S, Mak, HB, Marino, AD, McCauley, N, McDonald, AB, McDonald, DS, McFarlane, K, McGregor, G, McLatchie, W, Meijer Drees, R, Mes, H, Mifflin, C, Miller, GG, Milton, G, Moffat, BA, Moorhead, M, Nally, CW, Neubauer, MS, Newcomer, FM, Ng, HS, Noble, AJ, Norman, EB, Novikov, VM, O'Neill, M, Okada, CE, Ollerhead, RW, Omori, M, Orrell, JL, Oser, SM, Poon, AW, Radcliffe, TJ, Roberge, A, Robertson, BC, Robertson, RG, Rowley, JK, Rusu, VL, Saettler, E, Schaffer, KK, Schuelke, A, Schwendener, MH, Seifert, H, Shatkay, M, Simpson, JJ, Sinclair, D, Skensved, P, Smith, AR, Smith, MW, Starinsky, N, Steiger, TD, Stokstad, RG, Storey, RS, Sur, B, Tafirout, R, Tagg, N, Tanner, NW, Taplin, RK, Thorman, M, Thornewell, P, Trent, PT, Tserkovnyak, YI, Van Berg, R, Van de Water, RG, Virtue, CJ, Waltham, CE, Wang, JX, Wark, DL, West, N, Wilhelmy, JB, Wilkerson, JF, Wilson, J, Wittich, P, Wouters, JM, and Yeh, M
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High Energy Physics::Experiment ,Astrophysics::Earth and Planetary Astrophysics - Abstract
Solar neutrinos from (8)B decay have been detected at the Sudbury Neutrino Observatory via the charged current (CC) reaction on deuterium and the elastic scattering (ES) of electrons. The flux of nu(e)'s is measured by the CC reaction rate to be straight phi(CC)(nu(e)) = 1.75 +/- 0.07(stat)(+0.12)(-0.11)(syst) +/- 0.05(theor) x 10(6) cm(-2) s(-1). Comparison of straight phi(CC)(nu(e)) to the Super-Kamiokande Collaboration's precision value of the flux inferred from the ES reaction yields a 3.3 sigma difference, assuming the systematic uncertainties are normally distributed, providing evidence of an active non- nu(e) component in the solar flux. The total flux of active 8B neutrinos is determined to be 5.44+/-0.99 x 10(6) cm(-2) s(-1).
- Published
- 2001
5. The Sudbury Neutrino Observatory
- Author
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Boger, J, Hahn, RL, Rowley, JK, Carter, AL, Hollebone, B, Kessler, D, Blevis, I, Dalnoki-Veress, F, DeKok, A, Farine, J, Grant, DR, Hargrove, CK, Laberge, G, Levine, I, McFarlane, K, Mes, H, Noble, AT, Novikov, VM, O'Neill, M, Shatkay, M, Shewchuk, C, Sinclair, D, Clifford, ETH, Deal, R, Earle, ED, Gaudette, E, Milton, G, Sur, B, Bigu, J, Cowan, JHM, Cluff, DL, Hallman, ED, Haq, RU, Hewett, J, Hykawy, JG, Jonkmans, G, Michaud, R, Roberge, A, Roberts, J, Saettler, E, Schwendener, MH, Seifert, H, Sweezey, D, Tafirout, R, Virtue, CJ, Beck, DN, Chan, YD, Chen, X, Dragowsky, MR, Dycus, FW, Gonzalez, J, Isaac, MCP, Kajiyama, Y, Koehler, GW, Lesko, KT, Moebus, MC, Norman, EB, Okada, CE, Poon, AWP, Purgalis, P, Schuelke, A, Smith, AR, Stokstad, RG, Turner, S, Zlimen, I, Anaya, JM, Bowles, TJ, Brice, SJ, Esch, EI, Fowler, MM, Goldschmidt, A, Hime, A, McGirt, AF, Miller, GG, Teasdale, WA, Wilhelmy, JB, Wouters, JM, Anglin, JD, Bercovitch, M, Davidson, WF, Storey, RS, Biller, S, Black, RA, Boardman, RJ, Bowler, MG, Cameron, J, Cleveland, B, Ferraris, AP, Doucas, G, Heron, H, Howard, C, Jelley, NA, Knox, AB, Lay, M, Locke, W, Lyon, J, Majerus, S, Moorhead, M, Omori, M, Tanner, NW, Taplin, RK, Thorman, M, Wark, DL, West, N, Barton, JC, Trent, PT, Kouzes, R, Lowry, MM, Bell, AL, Bonvin, E, Boulay, M, Dayon, M, Duncan, F, Erhardt, LS, Evans, HC, Ewan, GT, Ford, R, Hallin, A, Hamer, A, Hart, PM, Harvey, PJ, Haslip, D, Hearns, CAW, Heaton, R, Hepburn, JD, Jillings, CJ, Korpach, EP, Lee, HW, Leslie, JR, Liu, MQ, Mak, HB, McDonald, AB, MacArthur, JD, McLatchie, W, Moffat, BA, Noel, S, Radcliffe, TJ, Robertson, BC, Skensved, P, Stevenson, RL, Zhu, X, Gil, S, Heise, J, Helmer, RL, Komar, RJ, Nally, CW, Ng, HS, Waltham, CE, Allen, RC, Buhler, G, Chen, HH, Aardsma, G, Andersen, T, Cameron, K, Chon, MC, Hanson, RH, Jagam, P, Karn, J, Law, J, Ollerhead, RW, Simpson, JJ, Tagg, N, Wang, JX, Alexander, C, Beier, EW, Cook, JC, Cowen, DF, Frank, ED, Frati, W, Keener, PT, Klein, JR, Mayers, G, McDonald, DS, Neubauer, MS, Newcomer, FM, Pearce, RJ, Van de Water, RG, Van Berg, R, Wittich, P, Ahmad, QR, Beck, JM, Browne, MC, Burritt, TH, Doe, PJ, Duba, CA, Elliott, SR, Franklin, JE, Germani, JV, Green, P, Hamian, AA, Heeger, KM, Howe, M, Drees, RM, Myers, A, Robertson, RGH, Smith, MWE, Steiger, TD, Van Wechel, T, Wilkerson, JF, and Collaboration, SNO
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Nuclear and High Energy Physics ,Physics - Instrumentation and Detectors ,Physics::Instrumentation and Detectors ,Solar neutrino ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics ,7. Clean energy ,01 natural sciences ,High Energy Physics - Experiment ,High Energy Physics - Experiment (hep-ex) ,High Energy Physics - Phenomenology (hep-ph) ,0103 physical sciences ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,010306 general physics ,Neutrino oscillation ,Instrumentation ,Physics ,Standard solar model ,Sudbury Neutrino Observatory ,010308 nuclear & particles physics ,Astrophysics (astro-ph) ,High Energy Physics::Phenomenology ,Instrumentation and Detectors (physics.ins-det) ,High Energy Physics - Phenomenology ,Neutrino detector ,High Energy Physics::Experiment ,Neutrino ,Electron neutrino ,Lepton - Abstract
The Sudbury Neutrino Observatory is a second generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D2O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible., 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and epsf style files. For additional information about SNO see http://www.sno.phy.queensu.ca . This version has some new references
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- 2000
6. Genetic Variation in theFASGene and Associations with Outcomes in Acute Lung Injury.
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Glavan, BJ, primary, Holden, TD, additional, Goss, CH, additional, Black, RA, additional, Martin, TR, additional, and Wurfel, MM, additional
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- 2009
- Full Text
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7. Genetic Variation inTLR1and Susceptibility to Trauma-Associated Sepsis and Related Outcomes.
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Wurfel, MM, primary, Holden, TD, additional, Black, RA, additional, Martin, TR, additional, and O'Keefe, GE, additional
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- 2009
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8. Effect of interleukin-1 beta converting enzyme inhibitor on acute myelogenous leukemia progenitor proliferation
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Estrov, Z, primary, Black, RA, additional, Sleath, PR, additional, Harris, D, additional, Van, Q, additional, LaPushin, R, additional, Estey, EH, additional, and Talpaz, M, additional
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- 1995
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9. Genetic variation in the FAS gene and associations with acute lung injury.
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Glavan BJ, Holden TD, Goss CH, Black RA, Neff MJ, Nathens AB, Martin TR, Wurfel MM, ARDSnet Investigators, Glavan, Bradford J, Holden, Tarah D, Goss, Christopher H, Black, R Anthony, Neff, Margaret J, Nathens, Avery B, Martin, Thomas R, and Wurfel, Mark M
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ANTIGENS ,DISEASE susceptibility ,GENES ,GENETIC polymorphisms ,GENETICS ,GENETIC techniques ,LUNG injuries ,RESEARCH funding ,CASE-control method ,ACUTE diseases ,GENOTYPES - Abstract
Rationale: Fas (CD95) modulates apoptosis and inflammation and is believed to play an important role in lung injury.Objectives: To determine if common genetic variation in FAS is associated with acute lung injury (ALI) susceptibility, risk of death, and FAS gene expression.Methods: We genotyped 14 single nucleotide polymorphisms (tagSNPS) in FAS in samples from healthy white volunteers (control subjects, n = 294) and patients with ALI (cases, n = 324) from the ARDSnet Fluid and Catheter Treatment Trial (FACTT). FAS genotypes associated with ALI in the discovery study were confirmed in a nested case-control validation study of critically ill patients at risk for ALI (n = 657). We also tested for associations between selected tagSNPS and FAS mRNA levels in whole blood from healthy control subjects exposed to media alone or LPS ex vivo.Measurements and Main Results: We identified associations between four tagSNPs in FAS (FAS(-11341A>T) [rs17447140], FAS(9325G>A) [rs2147420], FAS(21541C>T) [rs2234978], and FAS(24484A>T) [rs1051070]) and ALI case status. Haplotype-based analyses suggested that three of the tagSNPs (FAS(9325G>A), FAS(21541C>T), and FAS(24484A>T)) function as a unit. The association with this haplotype and ALI was validated in a nested case-control study of at-risk subjects (P = 0.05). This haplotype was also associated with increased FAS mRNA levels in response to LPS stimulation. There was no association between FAS polymorphisms and risk of death among ALI cases.Conclusions: Common genetic variants in FAS are associated with ALI susceptibility. This is the first genetic evidence supporting a role for FAS in ALI. [ABSTRACT FROM AUTHOR]- Published
- 2011
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10. Toll-like receptor 1 polymorphisms affect innate immune responses and outcomes in sepsis.
- Author
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Wurfel MM, Gordon AC, Holden TD, Radella F, Strout J, Kajikawa O, Ruzinski JT, Rona G, Black RA, Stratton S, Jarvik GP, Hajjar AM, Nickerson DA, Rieder M, Sevransky J, Maloney JP, Moss M, Martin G, Shanholtz C, and Garcia JG
- Abstract
Rationale: Polymorphisms affecting Toll-like receptor (TLR)-mediated responses could predispose to excessive inflammation during an infection and contribute to an increased risk for poor outcomes in patients with sepsis.Objectives: To identify hypermorphic polymorphisms causing elevated TLR-mediated innate immune cytokine and chemokine responses and to test whether these polymorphisms are associated with increased susceptibility to death, organ dysfunction, and infections in patients with sepsis.Methods: We screened single-nucleotide polymorphisms (SNPs) in 43 TLR-related genes to identify variants affecting TLR-mediated inflammatory responses in blood from healthy volunteers ex vivo. The SNP associated most strongly with hypermorphic responses was tested for associations with death, organ dysfunction, and type of infection in two studies: a nested case-control study in a cohort of intensive care unit patients with sepsis, and a case-control study using patients with sepsis, patients with sepsis-related acute lung injury, and healthy control subjects.Measurements and Main Results: The SNP demonstrating the most hypermorphic effect was the G allele of TLR1(-7202A/G) (rs5743551), which associated with elevated TLR1-mediated cytokine production (P < 2 x 10(-20)). TLR1(-7202G) marked a coding SNP that causes higher TLR1-induced NF-kappaB activation and higher cell surface TLR1 expression. In the cohort of patients with sepsis TLR1(-7202G) predicted worse organ dysfunction and death (odds ratio, 1.82; 95% confidence interval, 1.07-3.09). In the case-control study TLR1(-7202G) was associated with sepsis-related acute lung injury (odds ratio, 3.40; 95% confidence interval, 1.59-7.27). TLR1(-7202G) also associated with a higher prevalence of gram-positive cultures in both clinical studies.Conclusions: Hypermorphic genetic variation in TLR1 is associated with increased susceptibility to organ dysfunction, death, and gram-positive infection in sepsis. [ABSTRACT FROM AUTHOR]- Published
- 2008
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11. Measuring money mismanagement among dually diagnosed clients.
- Author
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Black RA, Rounsaville BJ, Rosenheck RA, Conrad KJ, Ball SA, Rosen MI, Black, Ryan A, Rounsaville, Bruce J, Rosenheck, Robert A, Conrad, Kendon J, Ball, Samuel A, and Rosen, Marc I
- Abstract
Clients dually diagnosed with psychiatric and substance abuse disorders may be adversely affected if they mismanage their Social Security or public support benefits. Assistance managing funds, including assignment of a representative payee, is available but there are no objective assessments of money mismanagement. In this study, a Structured Clinical Interview for Money Mismanagement was administered twice at 1-week intervals to 46 clients receiving disability payments and was compared with clinician's judgment that the client was incapable of managing funds, the frequent basis for payee assignment by the Social Security Administration and Veterans Affairs. Clinician's judgment and structured interview were concordant on 71% of capability judgments. The interview had high test-retest reliability and was correlated with self-reported money mismanagement and global assessment of functioning scale scores, but clinician judgment was not associated with these measures. Results suggest that the interview is sensitive in detecting money mismanagement and raises questions concerning the validity of clinicians' judgments. [ABSTRACT FROM AUTHOR]
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- 2008
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12. Alpha2(VIII) collagen substrata enhance endothelial cell retention under acute shear stress flow via an alpha2beta1 integrin-dependent mechanism: an in vitro and in vivo study.
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Turner NJ, Murphy MO, Kielty CM, Shuttleworth A, Black RA, Humphries MJ, Walker MG, Canfield AE, Turner, Neill J, Murphy, Michael O, Kielty, Cay M, Shuttleworth, C Adrian, Black, Richard A, Humphries, Martin J, Walker, Michael G, and Canfield, Ann E
- Published
- 2006
13. Over-the-counter medications in pregnancy.
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Black RA and Hill DA
- Abstract
Pregnant women commonly use over-the-counter medications. Although most over-the-counter drugs have an excellent safety profile, some have unproven safety or are known to adversely affect the fetus. The safety profile of some medications may change according to the gestational age of the fetus. Because an estimated 10 percent or more of birth defects result from maternal drug exposure, the U.S. Food and Drug Administration has assigned a risk category to each drug. Many drugs have not been evaluated in controlled trials and probably will not be because of ethical considerations. Of the commonly used over-the-counter medications, acetaminophen, chlorpheniramine, kaolin and pectin preparations, and most antacids have a good safety record. Other drugs, such as histamine H2-receptor blockers, pseudoephedrine, and atropine/diphenoxylate should be used with caution. If use of smoking cessation products is desired, the intermediate-release preparations minimize the amount of nicotine while maintaining efficacy. With all over-the-counter medications used during pregnancy, the benefit of the drug should outweigh the risk to the fetus. [ABSTRACT FROM AUTHOR]
- Published
- 2003
14. Vibration-induced shift of the subjective visual horizontal: a sign of unilateral vestibular deficit.
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Karlberg M, Aw ST, Halmagyi GM, and Black RA
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- 2002
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15. Semicircular canal plane head impulses detect absent function of individual semicircular canals.
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Cremer, PD, Halmagyi, GM, Aw, ST, Curthoys, IS, McGarvie, LA, Todd, MJ, Black, RA, and Hannigan, IP
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- 1998
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16. Crohn's disease and MAP.
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Huggett J, Dheda K, Zumla A, Rook G, Naser SA, Valentine JF, Gaya DR, Black RA, and MacKenzie JF
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- 2004
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17. Appropriateness of using numeric rating scales to assess risk perceptions for individuals with limited health numeracy.
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Shiffman S, Hannon MJ, McCaffrey SA, and Black RA
- Abstract
Objective: Numeric rating scales (NRSs) could be inappropriate for assessing constructs such as risk perception if individuals with limited health numeracy (LHN) have difficulty expressing their perceptions on such scales. This paper compares the psychometric functioning of numerical risk perception ratings for an e-cigarette obtained from LHN individuals, comparing them to those from individuals with adequate health numeracy (AHN)., Methods: In a randomized trial of a risk-related message (not evaluated here), participants (N = 12,557) used NRSs to rate their perception of (1) overall risk of harm (from 0 %-100 % harmful to health), and (2) likelihood (0-100 %) of suffering four tobacco-related diseases from using e-cigarettes; and used a 4-point adjectival scale ('not at all harmful' to 'very harmful') to rate the harm of using e-cigarettes. Based on the Newest Vital Sign (NVS), 29 % of participants were classified as LHN., Results: Numeric ratings of e-cigarette harm in LHN and AHN groups showed a nearly identical and equally strong relationship to verbal perceived risk ratings. Analyses of disease-specific ratings as a unidimensional scale demonstrated configural, metric, and scalar invariance between ratings from LHN and AHN individuals., Conclusion: LHN individuals are able to make meaningful ratings using numeric scales, comparable to those from AHN individuals., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: All authors report financial support was provided by Juul Labs Inc. Through Pinney Associates authors S.S. and M.J.H provide consulting services on tobacco harm reduction on an exclusive basis to Juul Labs Inc. Authors S.A.M. and R.A.B. are employees of Juul Labs Inc., (Copyright © 2024 Elsevier B.V. All rights reserved.)
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- 2024
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18. Professional firefighters: Findings from the National Wellness Survey for Public Safety Personnel.
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Gibbs ITS, Bourke ML, Van Hasselt VB, and Black RA
- Abstract
Professional firefighters are routinely exposed to occupational stressors that place them at a higher risk of developing mental health symptoms, including anxiety, depression, and posttraumatic stress. This article discusses findings of the National Wellness Survey for Public Safety Personnel, specifically the stressors that professional firefighters are exposed to on the job and their impact. Results indicated high levels of both occupational and individual stressors in this group. Common occupational and personal stressors and mental health symptomology endorsed by professional firefighters are discussed. Findings also revealed that about 40% of professional firefighters are facing clinically substantial levels of anxiety and depression, and more than 10% are experiencing clinically significant levels of posttraumatic stress disorder in numbers surpassing the general population. Most professional firefighters indicated being adversely impacted by their duties but did not want to utilize services, which is in line with prior research. Suggestions for assisting professional firefighters in mitigating occupational and personal stress are presented, and proposals for future research are provided. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
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- 2024
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19. Assessment of abuse liability and switching potential of menthol-flavored pod-based electronic nicotine delivery systems among US adults who smoke cigarettes.
- Author
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Goldenson NI, Shiffman S, Sembower MA, and Black RA
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- Humans, Male, Female, Adult, United States, Young Adult, Tobacco Products, Cigarette Smoking epidemiology, Middle Aged, Menthol, Electronic Nicotine Delivery Systems, Flavoring Agents, Cross-Over Studies
- Abstract
Background: Menthol-flavored electronic nicotine delivery systems (ENDS) are a focus of public health and regulatory policy considerations. The abuse liability of five menthol-flavored pod-based ENDS was compared to combustible cigarettes, and switching potential of ENDS was also evaluated., Methods: 215 US adults who smoke cigarettes (34.4% female; mean age[SD]=29.60[8.75]; 40.9% non-Hispanic White; mean cigarettes/day[SD]=12.04[8.52]) completed a randomized 6-arm within-person cross-over product-use study. Participants used five pod-based menthol-flavored ENDS (JUUL2 Polar Menthol 1.5%, JUUL2 Prototype Fresh Menthol 3.0%, JUUL Menthol 5.0%, Vuse Alto Menthol 5.0%, NJOY Ace Menthol 5.0%) and their usual brand (UB) cigarette for 20minutes ad libitum. After each product use, subjective reinforcing effects relevant to abuse liability and associated with switching away from cigarettes (e.g., satisfaction, product liking) were assessed., Results: All ENDS products were rated substantially and statistically significantly lower than UB cigarette on measures of subjective reinforcing effects (ps<0.001). Satisfying effects of JUUL2 1.5% were rated significantly higher than other ENDS products. JUUL2 Prototype 3.0% and Vuse Alto 5.0% did not significantly differ (ps>0.05), and both were rated significantly higher than JUUL 5.0% and NJOY Ace 5.0% (ps<0.05). Differences in subjective responses to study products did not significantly differ by preference for menthol cigarettes or by current ENDS use., Conclusions: Abuse liability of all menthol-flavored ENDS in this study was substantially lower than combustible cigarettes. Abuse liability of JUUL2 1.5% was within the range of currently marketed pod-based menthol-flavored ENDS products. JUUL2 1.5% likely has high potential for facilitating switching among US adults who smoke., Competing Interests: Declaration of Competing Interest Authors NIG and RAB are full-time employees of Juul Labs, Inc. (JLI). In their role as JLI employees, authors NIG and RAB contributed to the design, analysis, and interpretation of the data and to the writing of the paper. JLI employees had no role in the collection and management of the data. Other JLI employees reviewed the final draft for scientific accuracy and clarity, and for any legal issues, and approved it. Author SS is a senior advisor to PinneyAssociates and author MAS is a full-time employee of PinneyAssociates, Inc. PinneyAssociates provides consulting services on tobacco harm reduction on an exclusive basis to JLI., (Copyright © 2024 Elsevier B.V. All rights reserved.)
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- 2024
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20. Stabilization of Prebiotic Vesicles by Peptides Depends on Sequence and Chirality: A Mechanism for Selection of Protocell-Associated Peptides.
- Author
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Cohen ZR, Todd ZR, Maibaum L, Catling DC, and Black RA
- Subjects
- Alanine chemistry, Stereoisomerism, Artificial Cells chemistry, Leucine chemistry, Origin of Life, Dipeptides chemistry, Peptides chemistry
- Abstract
Cells require oligonucleotides and polypeptides with specific, homochiral sequences to perform essential functions, but it is unclear how such oligomers were selected from random sequences at the origin of life. Cells were probably preceded by simple compartments such as fatty acid vesicles, and oligomers that increased the stability, growth, or division of vesicles could have thereby increased in frequency. We therefore tested whether prebiotic peptides alter the stability or growth of vesicles composed of a prebiotic fatty acid. We find that three of 15 dipeptides tested reduce salt-induced flocculation of vesicles. All three contain leucine, and increasing their length increases the efficacy. Also, leucine-leucine but not alanine-alanine increases the size of vesicles grown by multiple additions of micelles. In a molecular simulation, leucine-leucine docks to the membrane, with the side chains inserted into the hydrophobic core of the bilayer, while alanine-alanine fails to dock. Finally, the heterochiral forms of leucine-leucine, at a high concentration, rapidly shrink the vesicles and make them leakier and less stable to high pH than the homochiral forms do. Thus, prebiotic peptide-membrane interactions influence the flocculation, growth, size, leakiness, and pH stability of prebiotic vesicles, with differential effects due to sequence, length, and chirality. These differences could lead to a population of vesicles enriched for peptides with beneficial sequence and chirality, beginning selection for the functional oligomers that underpin life.
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- 2024
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21. Comparing Adult Smokers Who Switched to JUUL versus Continuing Smokers: Biomarkers of Exposure and of Potential Harm and Respiratory Symptoms.
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Shiffman S, Oliveri DR, Goldenson NI, Liang Q, Black RA, and Mishra S
- Subjects
- Adult, Humans, Smokers, Cross-Sectional Studies, Smoking adverse effects, Nicotine adverse effects, Biomarkers analysis, Hazardous Substances analysis, Tobacco Products, Electronic Nicotine Delivery Systems
- Abstract
Objectives: Real-world evidence on exposure to harmful and potentially harmful constituents (HPHCs) and on biological effects in cigarette smokers who switch to electronic nicotine delivery systems (ENDS) can inform the health effects of switching., Aims and Methods: This cross-sectional, observational study assessed adults who had smoked ≥10 cigarettes/day for ≥10 years, comparing 124 continuing cigarette smokers (Smokers) to 140 former smokers who switched to JUUL-brand ENDS exclusively for ≥6 months (Switchers). Assessments included biomarkers of exposure (BOEs) to select HPHCs, biomarkers of potential harm (BOPHs) related to smoking-related diseases, psychometric assessments of dependence on cigarettes and ENDS, respectively, and respiratory symptoms. Planned analyses compared geometric means, adjusted for demographic covariates; further analyses adjusted for additional lifestyle and smoking history covariates., Results: Nicotine levels were significantly higher in Switchers (median time switched = 3 years), who were unusually heavy users of JUUL. All other BOEs, including NNAL and HPMA3 (primary endpoints), were significantly lower in Switchers than Smokers. Most BOPHs (sICAM-1 [primary], and eg, white blood cell count, MCP1, HbA1c) were significantly lower in Switchers than Smokers; HDL was significantly higher. Switchers reported significantly lower dependence on JUUL than Smokers did on cigarettes, and respiratory symptom scores were significantly lower among Switchers than Smokers., Conclusions: Compared to continuing smokers, smokers who switched to JUUL had substantially lower exposures to multiple HPHCs, favorable differences in markers of inflammation, endothelial function, oxidative stress, and cardiovascular risk, and fewer respiratory symptoms. These findings suggest that switching from cigarettes to JUUL likely reduces smokers' health risks., Implications: Short-term confinement studies and randomized clinical trials demonstrate that adult smokers who switch completely to ENDS experience substantial reductions in exposure to many smoking-related toxicants. This study extends those findings to longer periods of switching to JUUL-brand ENDS (almost 3 years on average) under naturalistic use conditions in real-world settings and also found that switching to JUUL resulted in favorable differences in BOPHs more proximally related to smoking-induced disease, as well as in respiratory symptoms. Smokers who switch to ENDS reduce their exposure to toxicants, likely reducing their disease risk., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
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- 2024
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22. Natural soda lakes provide compatible conditions for RNA and membrane function that could have enabled the origin of life.
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Cohen ZR, Ding D, Zhou L, DasGupta S, Haas S, Sinclair KP, Todd ZR, Black RA, Szostak JW, and Catling DC
- Abstract
The origin of life likely occurred within environments that concentrated cellular precursors and enabled their co-assembly into cells. Soda lakes (those dominated by Na
+ ions and carbonate species) can concentrate precursors of RNA and membranes, such as phosphate, cyanide, and fatty acids. Subsequent assembly of RNA and membranes into cells is a long-standing problem because RNA function requires divalent cations, e.g. Mg2+ , but Mg2+ disrupts fatty acid membranes. The low solubility of Mg-containing carbonates limits soda lakes to moderate Mg2+ concentrations (∼1 mM), so we investigated whether both RNAs and membranes function within these lakes. We collected water from Last Chance Lake and Goodenough Lake in Canada. Because we sampled after seasonal evaporation, the lake water contained ∼1 M Na+ and ∼1 mM Mg2+ near pH 10. In the laboratory, nonenzymatic, RNA-templated polymerization of 2-aminoimidazole-activated ribonucleotides occurred at comparable rates in lake water and standard laboratory conditions (50 mM MgCl2 , pH 8). Additionally, we found that a ligase ribozyme that uses oligonucleotide substrates activated with 2-aminoimidazole was active in lake water after adjusting pH from ∼10 to 9. We also observed that decanoic acid and decanol assembled into vesicles in a dilute solution that resembled lake water after seasonal rains, and that those vesicles retained encapsulated solutes despite salt-induced flocculation when the external solution was replaced with dry-season lake water. By identifying compatible conditions for nonenzymatic and ribozyme-catalyzed RNA assembly, and for encapsulation by membranes, our results suggest that soda lakes could have enabled cellular life to emerge on Earth, and perhaps elsewhere., (© The Author(s) 2024. Published by Oxford University Press on behalf of National Academy of Sciences.)- Published
- 2024
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23. Assessment of psychological functioning in retired firefighters.
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Pepper JS, Van Hasselt VB, Black RA, and Schneider BA
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- Humans, Aged, Depression psychology, Retirement, Anxiety, Firefighters psychology, Stress Disorders, Post-Traumatic psychology
- Abstract
The past decade has witnessed increased clinical and investigative attention directed to the mental health of active-duty firefighters. Yet, to our knowledge, no investigations have focused on the well-being of retired firefighters, despite awareness of retirement posing significant challenges for many older adults in general, and, in particular, first responders. The purpose of this study was to (a) conduct an initial assessment of psychological functioning in 315 retired firefighters, (b) examine the relationship between overall psychological functioning and self-concept clarity (i.e., the extent to which an individual's self-concept is clearly defined, internally consistent, and temporally stable), and (c) determine whether self-concept clarity moderates and/or mediates relationships between psychological functioning and relevant demographic and personal variables. Results indicated firefighters suffer from mental health symptoms associated with psychological disorders, such as depression and posttraumatic stress disorder, at higher rates than their same-aged counterparts in the general population. Furthermore, results showed that factors like age, length of time on active duty, and length of time retired, each significantly correlated with overall psychological functioning. Finally, results suggested that self-concept clarity both mediates and moderates the association between overall psychological functioning and personal factors such as daily levels of pain, feelings of financial stability, and access to affordable health care. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
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- 2024
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24. Three-dimensional biofabrication of nanosecond laser micromachined nanofibre meshes for tissue engineered scaffolds.
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McWilliam RH, Chang W, Liu Z, Wang J, Han F, Black RA, Wu J, Luo X, Li B, and Shu W
- Abstract
There is a high demand for bespoke grafts to replace damaged or malformed bone and cartilage tissue. Three-dimensional (3D) printing offers a method of fabricating complex anatomical features of clinically relevant sizes. However, the construction of a scaffold to replicate the complex hierarchical structure of natural tissues remains challenging. This paper reports a novel biofabrication method that is capable of creating intricately designed structures of anatomically relevant dimensions. The beneficial properties of the electrospun fibre meshes can finally be realised in 3D rather than the current promising breakthroughs in two-dimensional (2D). The 3D model was created from commercially available computer-aided design software packages in order to slice the model down into many layers of slices, which were arrayed. These 2D slices with each layer of a defined pattern were laser cut, and then successfully assembled with varying thicknesses of 100 μm or 200 μm. It is demonstrated in this study that this new biofabrication technique can be used to reproduce very complex computer-aided design models into hierarchical constructs with micro and nano resolutions, where the clinically relevant sizes ranging from a simple cube of 20 mm dimension, to a more complex, 50 mm-tall human ears were created. In-vitro cell-contact studies were also carried out to investigate the biocompatibility of this hierarchal structure. The cell viability on a micromachined electrospun polylactic-co-glycolic acid fibre mesh slice, where a range of hole diameters from 200 μm to 500 μm were laser cut in an array where cell confluence values of at least 85% were found at three weeks. Cells were also seeded onto a simpler stacked construct, albeit made with micromachined poly fibre mesh, where cells can be found to migrate through the stack better with collagen as bioadhesives. This new method for biofabricating hierarchical constructs can be further developed for tissue repair applications such as maxillofacial bone injury or nose/ear cartilage replacement in the future.
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- 2023
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25. Comparison of biomarkers of exposure among US adult smokers, users of electronic nicotine delivery systems, dual users and nonusers, 2018-2019.
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Holt NM, Shiffman S, Black RA, Goldenson NI, Sembower MA, and Oldham MJ
- Subjects
- Adult, Humans, Smokers, Nicotine, Biomarkers analysis, Electronic Nicotine Delivery Systems, Tobacco Products, Epilepsies, Partial
- Abstract
The harm caused by cigarette smoking is overwhelmingly due to byproducts of tobacco combustion. Electronic Nicotine Delivery Systems (ENDS) provide nicotine to users without combustion, and may support tobacco harm reduction among cigarette smokers who would not otherwise quit in the near term. Analyses of Wave 5 of the Population Assessment of Tobacco and Health (PATH) Study compared biomarkers of exposure (BOE) levels for nicotine, 3 metals, 2 tobacco-specific nitrosamines and 14 smoking-related volatile organic compounds in 151 exclusive ENDS users, 1341 exclusive cigarette smokers, 115 dual users (cigarettes and ENDS), and 1846 past 30-day nonusers of tobacco, adjusting for demographics. Nicotine exposure in ENDS users and dual users did not significantly differ from smokers. Among ENDS users, 16 of 18 other BOEs were significantly lower than smokers'; 9 BOEs were not significantly different from nonusers. Among dual users smoking < 10 cigarettes/day, 15 of 18 non-nicotine BOEs were significantly lower than smokers', whereas in dual users smoking ≥ 10 cigarettes per day none of the BOEs significantly differed from smokers'. In this representative sample of US adults, exclusive use of ENDS (vs. cigarette smoking) was associated with much lower exposures to many harmful chemicals associated with smoking-related disease. BOE levels in dual users were directly related to their cigarette consumption. These BOE data provide further evidence that ENDS expose users to substantially lower levels of toxicants than combustible cigarettes, confirming their potential for harm reduction., (© 2023. The Author(s).)
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- 2023
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26. A New Questionnaire to Assess Respiratory Symptoms (The Respiratory Symptom Experience Scale): Quantitative Psychometric Assessment and Validation Study.
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Shiffman S, McCaffrey SA, Hannon MJ, Goldenson NI, and Black RA
- Abstract
Background: Smokers often experience respiratory symptoms (eg, morning cough), and those who stop smoking, including those who do so by switching completely to electronic nicotine delivery systems (ENDS), may experience reductions in symptoms. Existing respiratory symptom questionnaires may not be suitable for studying these changes, as they are intended for patient populations, such as those with chronic obstructive pulmonary disease (COPD)., Objective: This study aimed to develop a respiratory symptom questionnaire appropriate for current smokers and for assessing changes when smokers stop smoking., Methods: The Respiratory Symptom Experience Scale (RSES) was derived from existing instruments and subject matter expert input and refined through cognitive debriefing interviews (n=49). Next, for purposes of the quantitative psychometric evaluation, the RSES was administered to smokers (n=202), former smokers (no tobacco use in >6 months; n=200), and switchers (n=208, smokers who switched to ENDS for >6 months), all of whom had smoked for at least 10 years (mean age 33 years). Participants, who averaged 62 (SD 12) years of age, included 28% (173/610) with respiratory allergy symptoms and 17% (104/610) with COPD. Test-retest reliability was assessed by repeat assessment after 1 week in 128 participants., Results: A generalized partial credit model confirmed that the response options were ordered, and a parallel analysis using principal components confirmed that the scale was unidimensional. With allowance for 2 sets of correlated errors between pairs of items, a 1-factor graded response model fit the data. Discrimination parameters were approximately 1 or greater for all items. Scale reliability was 0.80 or higher across a broad range of severity (standardized scores -0.40 to 3.00). Test-retest reliability (absolute intraclass correlation) was good, at 0.89. RSES convergent validity was supported by substantial differences (Cohen d=0.74) between those with and without a diagnosis of respiratory disease (averaging 0.57 points, indicating that differences of this size or smaller represent meaningful differences). RSES scores also strongly differentiated those with and without COPD (d=1.52). Smokers' RSES scores were significantly higher than former smokers' scores (P<.001). Switchers' RSES scores were significantly lower than smokers' scores (P<.001) and no different from former smokers' scores (P=.34)., Conclusions: The RSES fills an important gap in the existing toolkit of respiratory symptom questionnaires; it is a reliable and valid tool to assess respiratory symptoms in adult current and former smokers, including those who have switched to noncombusted nicotine products. This suggests that the scale is sensitive to respiratory symptoms that develop in smokers and to their remission when smokers quit or switch to noncombusted nicotine products intended to reduce the harm of smoking. The findings also suggest that switching from cigarettes to ENDS may improve respiratory health., (©Saul Shiffman, Stacey A McCaffrey, Michael J Hannon, Nicholas I Goldenson, Ryan A Black. Originally published in JMIR Formative Research (https://formative.jmir.org), 14.04.2023.)
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- 2023
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27. Plausible Sources of Membrane-Forming Fatty Acids on the Early Earth: A Review of the Literature and an Estimation of Amounts.
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Cohen ZR, Todd ZR, Wogan N, Black RA, Keller SL, and Catling DC
- Abstract
The first cells were plausibly bounded by membranes assembled from fatty acids with at least 8 carbons. Although the presence of fatty acids on the early Earth is widely assumed within the astrobiology community, there is no consensus regarding their origin and abundance. In this Review, we highlight three possible sources of fatty acids: (1) delivery by carbonaceous meteorites, (2) synthesis on metals delivered by impactors, and (3) electrochemical synthesis by spark discharges. We also discuss fatty acid synthesis by UV or particle irradiation, gas-phase ion-molecule reactions, and aqueous redox reactions. We compare estimates for the total mass of fatty acids supplied to Earth by each source during the Hadean eon after an extremely massive asteroid impact that would have reset Earth's fatty acid inventory. We find that synthesis on iron-rich surfaces derived from the massive impactor in contact with an impact-generated reducing atmosphere could have contributed ∼10
2 times more total mass of fatty acids than subsequent delivery by either carbonaceous meteorites or electrochemical synthesis. Additionally, we estimate that a single carbonaceous meteorite would not deliver a high enough concentration of fatty acids (∼15 mM for decanoic acid) into an existing body of water on the Earth's surface to spontaneously form membranes unless the fatty acids were further concentrated by another mechanism, such as subsequent evaporation of the water. Our estimates rely heavily on various assumptions, leading to significant uncertainties; nevertheless, these estimates provide rough order-of-magnitude comparisons of various sources of fatty acids on the early Earth. We also suggest specific experiments to improve future estimates. Our calculations support the view that fatty acids would have been available on the early Earth. Further investigation is needed to assess the mechanisms by which fatty acids could have been concentrated sufficiently to assemble into membranes during the origin of life., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)- Published
- 2022
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28. Growth of Prebiotically Plausible Fatty Acid Vesicles Proceeds in the Presence of Prebiotic Amino Acids, Dipeptides, Sugars, and Nucleic Acid Components.
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Todd ZR, Cohen ZR, Catling DC, Keller SL, and Black RA
- Subjects
- Amino Acids chemistry, Sugars, Dipeptides, Micelles, Fatty Acids chemistry, Nucleic Acids
- Abstract
Fatty acid vesicles may have played a role in the origin of life as a major structural component of protocells, with the potential for encapsulation of genetic materials. Vesicles that grew and divided more rapidly than other vesicles could have had a selective advantage. Fatty acid vesicles grow by incorporating additional fatty acids from micelles, and certain prebiotic molecules (e.g., sugars, nucleobases, and amino acids) can bind to fatty acid vesicles and stabilize them. Here, we investigated whether the presence of a variety of biomolecules affects the overall growth of vesicles composed of decanoic acid, a prebiotically plausible fatty acid, upon micelle addition. We tested 31 molecules, including 15 dipeptides, 7 amino acids, 6 nucleobases or nucleosides, and 3 sugars. We find that the initial radius and final radius of vesicles are largely unaffected by the presence of the additional compounds. However, three dipeptides enhanced the initial rates of growth compared to control vesicles with no small molecules added; another three dipeptides decreased the initial rates of growth. We conclude that vesicles can indeed grow in the presence of a wide range of molecules likely to have been involved in the origin of life. These results imply that vesicles would have been able to grow in complex and heterogeneous chemical environments. We find that the molecules that enhance the initial growth rate tend to have hydrophobic groups (e.g., leucine), which may interact with the lipid membrane to affect growth rate; furthermore, the molecules that cause the largest decrease in initial growth rate are dipeptides containing a serine residue, which contains a hydroxyl group that could potentially hydrogen-bond with the fatty acid carboxylate groups.
- Published
- 2022
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29. Prebiotic Vesicles Retain Solutes and Grow by Micelle Addition after Brief Cooling below the Membrane Melting Temperature.
- Author
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Cohen ZR, Todd ZR, Catling DC, Black RA, and Keller SL
- Subjects
- Temperature, Prebiotics, Fatty Acids, RNA, Carbon, Micelles, Cold Temperature
- Abstract
Replication of RNA genomes within membrane vesicles may have been a critical step in the development of protocells on the early Earth. Cold temperatures near 0 °C improve the stability of RNA and allow efficient copying, while some climate models suggest a cold early Earth, so the first protocells may have arisen in cold-temperature environments. However, at cold temperatures, saturated fatty acids, which would have been available on the early Earth, form gel-phase membranes that are rigid and restrict mobility within the bilayer. Two primary roles of protocell membranes are to encapsulate solutes and to grow by incorporating additional fatty acids from the environment. We test here whether fatty acid membranes in the gel phase accomplish these roles. We find that gel-phase membranes of 10-carbon amphiphiles near 0 °C encapsulate aqueous dye molecules as efficiently as fluid-phase membranes do, but the contents are released if the aqueous solution is frozen at -20 °C. Gel-phase membranes do not grow measurably by micelle addition, but growth resumes when membranes are warmed above the gel-liquid transition temperature. We find that longer, 12-carbon amphiphiles do not retain encapsulated contents near 0 °C. Together, our results suggest that protocells could have developed within environments that experience temporary cooling below the membrane melting temperature, and that membranes composed of relatively short-chain fatty acids would encapsulate solutes more efficiently as temperatures approached 0 °C.
- Published
- 2022
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30. Special issue-Sharing of best practices in response to the COVID-19 pandemic.
- Author
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Black RA
- Published
- 2022
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31. Understanding heterogeneity among individuals who smoke cigarettes and vape: assessment of biomarkers of exposure and potential harm among subpopulations from the PATH Wave 1 Data.
- Author
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Lizhnyak PN, Noggle B, Wei L, Edmiston J, Becker E, Black RA, and Sarkar M
- Subjects
- Biomarkers, Humans, Nicotiana, Cigarette Smoking, Electronic Nicotine Delivery Systems, Tobacco Products, Vaping
- Abstract
Introduction: People who both smoke cigarettes and vape are often considered as a homogenous group even though multiple subgroups may exist. We examined biomarkers of exposure (BOE) and biomarkers of potential harm (BOPH) to differentiate between subgroups of people who smoke and vape based on PATH Study Wave 1 (2013-2014) data., Methods: We compared people who only smoke cigarettes everyday (Group A, n = 2442) and people who only vape everyday (Group C, n = 169) against people who smoke and vape segmented into subgroups of people who frequently smoke and vape (Group B1, n = 169), frequently smoke and infrequently vape (Group B2, n = 678), frequently vape and infrequently smoke (Group B3, n = 57), and infrequently smoke and vape (Group B4, n = 66). Eighteen BOEs (representing exposure to TSNAs, nicotine, heavy metals, PAHs, and volatile organic compounds) and four BOPHs (representing inflammation and oxidative stress) were compared within the subgroups., Results: Levels of many BOEs/BOPHs were higher among Group B2 relative to Groups B1, B3, and B4. Compared to Group A, many BOEs were significantly lower in Groups B3 (15/18) and B4 (17/18), and some BOEs were higher among B2 (4/18). Compared to Group C, significantly lower BOEs were observed for Group B4 (2/18)., Conclusions: Overall, the levels of BOEs and BOPHs in people who smoke and vape are associated with frequency of cigarette smoking. Our findings indicate that not all people who smoke and vape are the same, and tobacco product use frequency should be considered when categorizing people who smoke and vape., (© 2022. The Author(s).)
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- 2022
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32. A Behavioral-Analytic Model for Assessing Stress in Firefighters.
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Schuhmann BB, Henderson SN, Black RA, Van Hasselt VB, Klimley Margres K, Masias EV, and LeDuc TJ
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- Humans, Psychometrics methods, Reproducibility of Results, United States, Firefighters psychology
- Abstract
Research has documented a number of acute and chronic stressors unique to the fire service. Due to the rise in mental health concerns in firefighters, there has been increased awareness of the negative effects of unmanaged stress. The present study employed a behavioral-analytic model to construct a brief screening measure of stress for this population: the Firefighter Assessment of Stress Test (FAST). Psychometric properties of the FAST were evaluated using data from active-duty firefighters throughout the United States. Results indicated the FAST has good internal reliability ( α = 0.89), as well as good convergent and discriminant validity. Also, the factor structure of the FAST revealed three significant subscales reflective of stress associated with responding to calls, administrative difficulties, and being overworked. Scoring and interpretation guidelines were established to suggest when further assessment is warranted. The FAST offers a brief and valid method of self-assessment of current stress levels in firefighters. Information obtained from the FAST (i.e., overall stress level and domains) has the potential to facilitate more immediate identification and recognition of stress in firefighters than what has been possible to date. Moreover, heightened awareness of stress and its effects will hopefully culminate in expanded efforts directed toward stress reduction and intervention for firefighters and their families.
- Published
- 2022
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33. Prebiotic Membranes and Micelles Do Not Inhibit Peptide Formation During Dehydration.
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Cohen ZR, Kessenich BL, Hazra A, Nguyen J, Johnson RS, MacCoss MJ, Lalic G, Black RA, and Keller SL
- Subjects
- Dehydration, Peptides chemistry, Protein Conformation, Temperature, Decanoic Acids chemistry, Peptides chemical synthesis
- Abstract
Cycles of dehydration and rehydration could have enabled formation of peptides and RNA in otherwise unfavorable conditions on the early Earth. Development of the first protocells would have hinged upon colocalization of these biopolymers with fatty acid membranes. Using atomic force microscopy, we find that a prebiotic fatty acid (decanoic acid) forms stacks of membranes after dehydration. Using LC-MS-MS (liquid chromatography-tandem mass spectrometry) with isotope internal standards, we measure the rate of formation of serine dipeptides. We find that dipeptides form during dehydration at moderate temperatures (55 °C) at least as fast in the presence of decanoic acid membranes as in the absence of membranes. Our results are consistent with the hypothesis that protocells could have formed within evaporating environments on the early Earth., (© 2021 Wiley-VCH GmbH.)
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- 2022
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34. Prebiotic Protocell Membranes Retain Encapsulated Contents during Flocculation, and Phospholipids Preserve Encapsulation during Dehydration.
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Cohen ZR, Cornell CE, Catling DC, Black RA, and Keller SL
- Subjects
- Dehydration, Fatty Acids, Flocculation, Humans, Artificial Cells, Phospholipids
- Abstract
The first cell membranes were likely composed of single-chain amphiphiles such as fatty acids. An open question is whether fatty acid membranes could have functioned within evaporative lakes on the early Earth, which have been hypothesized to concentrate prebiotic reactants. Evaporation also concentrates monovalent salts, which in turn cause fatty acid membrane vesicles to flocculate; significant loss of encapsulated contents during flocculation would have impeded early cell evolution. Here, we tested whether fatty acid vesicles retain encapsulated contents after flocculation and after drying. We found that vesicles composed of 2:1 decanoic acid:decanol encapsulate calcein dye throughout a process of flocculation in saturated salt solution and subsequent disaggregation of vesicles by dilution of the salt. However, 30 minutes of complete dehydration disrupted encapsulation by fatty acid vesicles. In contrast, phospholipid vesicles maintained encapsulation. Our results reveal a selective pressure for protocells to incorporate phospholipids: while fatty acid membranes can retain encapsulated contents during periods of dilute and saturating salt, phospholipids are necessary for encapsulation during dry periods. Our results are consistent with the hypothesis that evaporative lakes were productive sites for prebiotic chemistry and the origin of cells.
- Published
- 2022
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35. Binding of Dipeptides to Fatty Acid Membranes Explains Their Colocalization in Protocells but Does Not Select for Them Relative to Unjoined Amino Acids.
- Author
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Xue M, Black RA, Cohen ZR, Roehrich A, Drobny GP, and Keller SL
- Subjects
- Amino Acids, Dipeptides, Fatty Acids, Proteins, Artificial Cells
- Abstract
Dipeptides, which consist of two amino acids joined by a peptide bond, have been shown to have catalytic functions. This observation leads to fundamental questions relevant to the origin of life. How could peptides have become colocalized with the first protocells? Which structural features would have determined the association of amino acids and peptides with membranes? Could the association of dipeptides with protocell membranes have driven molecular evolution, favoring dipeptides over individual amino acids? Using pulsed-field gradient nuclear magnetic resonance, we find that several prebiotic amino acids and dipeptides bind to prebiotic membranes. For amino acids, the side chains and carboxylate contribute to the interaction. For dipeptides, the extent of binding is generally less than that of the constituent amino acids, implying that other mechanisms would be necessary to drive molecular evolution. Nevertheless, our results are consistent with a scheme in which the building blocks of the biological polymers colocalized with protocells prior to the emergence of RNA and proteins.
- Published
- 2021
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36. Epidemiology of antimicrobial resistance (AMR) on California dairies: descriptive and cluster analyses of AMR phenotype of fecal commensal bacteria isolated from adult cows.
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Abdelfattah EM, Ekong PS, Okello E, Chamchoy T, Karle BM, Black RA, Sheedy D, ElAshmawy WR, Williams DR, Califano D, Tovar LFD, Ongom J, Lehenbauer TW, Byrne BA, and Aly SS
- Abstract
Background: This study describes the occurrence of antimicrobial resistance (AMR) in commensal Escherichia coli and Enterococcus/Streptococcus spp. (ES) isolated from fecal samples of dairy cows and assesses the variation of AMR profiles across regions and seasons following the implementation of the Food and Agricultural Code (FAC) Sections 14400-14408 (formerly known as Senate Bill, SB 27) in California (CA)., Methods: The study was conducted on ten dairies distributed across CA's three milk sheds: Northern California (NCA), Northern San Joaquin Valley (NSJV), and the Greater Southern California (GSCA). On each study dairy, individual fecal samples were collected from two cohorts of lactating dairy cows during the fall/winter 2018 and spring/summer 2019 seasons. Each cohort comprised of 12 cows per dairy. The fecal samples were collected at enrollment before calving (close-up stage) and then monthly thereafter for four consecutive time points up to 120 days in milk. A total of 2,171 E. coli and 2,158 ES isolates were tested for antimicrobial susceptibility using the broth microdilution method against a select panel of antimicrobials., Results: The E. coli isolates showed high resistance to florfenicol (83.31% ± 0.80) and sulphadimethoxine (32.45%), while resistance to ampicillin (1.10% ± 0.21), ceftiofur (1.93% ± 0.29), danofloxacin (4.01% ± 0.42), enrofloxacin (3.31% ± 0.38), gentamicin (0.32% ± 0.12) and neomycin (1.61% ± 0.27) had low resistance proportions. The ES isolates were highly resistant to tildipirosin (50.18% ± 1.10), tilmicosin (48% ± 1.10), tiamulin (42%) and florfenicol (46% ± 1.10), but were minimally resistant to ampicillin (0.23%) and penicillin (0.20%). Multidrug resistance (MDR) (resistance to at least 1 drug in ≥3 antimicrobial classes) was observed in 14.14% of E. coli isolates and 39% of ES isolates. Escherichia coli isolates recovered during winter showed higher MDR prevalence compared to summer isolates (20.33% vs. 8.04%). A higher prevalence of MDR was observed in NSJV (17.29%) and GSCA (15.34%) compared with NCA (10.10%)., Conclusions: Our findings showed high rates of AMR to several drugs that are not labeled for use in lactating dairy cattle 20 months of age or older. Conversely, very low resistance was observed for drugs labeled for use in adult dairy cows, such as cephalosporins and penicillin. Overall, our findings identified important differences in AMR by antimicrobial class, region and season., Competing Interests: Sharif Aly is an Academic Editor for PeerJ., (© 2021 Abdelfattah et al.)
- Published
- 2021
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37. Development and validation of behavioral intention measures of an E-vapor product: intention to try, use, dual use, and switch.
- Author
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McCaffrey SA, Zdinak JP, Plunkett S, Becker E, Lewis JN, and Black RA
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Female, Humans, Male, Middle Aged, Reproducibility of Results, Young Adult, Intention, Psychometrics standards, Risk Reduction Behavior, Smokers psychology, Smoking psychology, Vaping psychology
- Abstract
Background: The harm caused by tobacco use is primarily attributable to cigarette smoking. Switching completely to non-combustible products may reduce disease risks in adult cigarette smokers who are unable or unwilling to quit. Before a new tobacco product can enter the market or can be marketed as a modified risk tobacco product, the manufacturer must determine the impact that the product will have on the likelihood of changes in tobacco use behavior among both tobacco users and nonusers. One way to estimate change in tobacco use behavior is to assess tobacco users' and nonusers' behavioral intentions toward the product and its marketing, including intentions to try, use, dual use, and switch to the product from cigarettes. The purpose of this study was to develop and validate behavioral intention metrics appropriate for use with current, former, and never adult tobacco users., Methods: Preliminary items were subjected to cognitive testing with adult (1) smokers planning to quit cigarettes in the next 30 days, (2) smokers not planning to quit cigarettes in the next 30 days, (3) e-vapor users, (4) former tobacco users, and (5) never tobacco users. Items were iteratively revised based on feedback during cognitive testing, and surviving items were administered to a large sample of adults (N = 2943) representing the aforementioned sub-groups. Rating scale functioning, reliability, validity, bias, and ability to detect change were evaluated., Results: Examination of the response category thresholds generated by the Rasch model provided evidence that the rating scales were functioning appropriately. Results revealed good stability and excellent internal consistency and person reliability and provided evidence of unidimensionality and convergent validity. Estimates of reliability and validity were similar across sub-groups. A cross-validation sample generally confirmed findings from the validation sample. No items were discarded due to differential item function. Exploratory analyses provided support for ability to detect change., Conclusions: Results from this rigorous, empirical evaluation using large validation and cross-validation samples provide strong support for the psychometric properties of the Intention to Try, Use, Dual Use, and Switch scales with current, former, and never adult tobacco users.
- Published
- 2021
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38. An improved process for the fabrication and surface treatment of custom-made titanium cranioplasty implants informed by surface analysis.
- Author
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Cardona MJ, Turner C, Ross C, Baird E, and Black RA
- Subjects
- Biocompatible Materials metabolism, Bone Substitutes metabolism, Humans, Prosthesis Implantation, Silicon chemistry, Skull, Surface Properties, Titanium metabolism, Biocompatible Materials chemistry, Bone Substitutes chemistry, Titanium chemistry
- Abstract
Cranioplasty implants are routinely fabricated from commercially pure titanium plates by maxillofacial prosthetists. The differing fabrication protocols adopted by prosthetists working at different hospital sites gives rise to considerable variations in surface topography and composition of cranioplasty implants, with residues from the fabrication processes having been found to become incorporated into the surface of the implant. There is a growing recognition among maxillofacial prosthetists of the need to standardise these protocols to ensure quality and consistency of practice within the profession. In an effort to identify and eliminate the source of the inclusions associated with one such fabrication protocol, the present study examined the surfaces of samples subjected to each of the manufacturing steps involved. Surface and elemental analysis techniques identified the main constituent of the surface inclusions to be silicon from the glass beads used to texture the surface of the implant during fabrication. Subsequent analysis of samples prepared according to a revised protocol resulted in a more homogeneous titanium dioxide surface as evidenced by the reduction in area occupied by surface inclusions (from 8.51% ± 2.60% to 0.93% ± 0.62%). These findings may inform the development of improved protocols for the fabrication of titanium cranioplasty plates.
- Published
- 2021
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39. A Step toward Molecular Evolution of RNA: Ribose Binds to Prebiotic Fatty Acid Membranes, and Nucleosides Bind Better than Individual Bases Do.
- Author
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Xue M, Black RA, Cornell CE, Drobny GP, and Keller SL
- Subjects
- Binding Sites, Nuclear Magnetic Resonance, Biomolecular, Origin of Life, Particle Size, Decanoic Acids chemistry, Evolution, Chemical, Nucleosides chemistry, RNA chemistry, Ribose chemistry
- Abstract
A major challenge in understanding how biological cells arose on the early Earth is explaining how RNA and membranes originally colocalized. We propose that the building blocks of RNA (nucleobases and ribose) bound to self-assembled prebiotic membranes. We have previously demonstrated that the bases bind to membranes composed of a prebiotic fatty acid, but evidence for the binding of sugars has remained a technical challenge. Here, we used pulsed-field gradient NMR spectroscopy to demonstrate that ribose and other sugars bind to membranes of decanoic acid. Moreover, the binding of some bases is strongly enhanced when they are linked to ribose to form a nucleoside or - with the addition of phosphate - a nucleotide. This enhanced binding could have played a role in the molecular evolution leading to the production of RNA., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2020
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40. Probing fibronectin adsorption on chemically defined surfaces by means of single molecule force microscopy.
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Liamas E, Black RA, Mulheran PA, Tampé R, Wieneke R, Thomas ORT, and Zhang ZJ
- Subjects
- Adsorption, Gold chemistry, Humans, Surface Properties, Fibronectins chemistry, Single Molecule Imaging
- Abstract
Atomic force microscope (AFM) based single molecule force spectroscopy (SMFS) and a quartz crystal microbalance (QCM) were respectively employed to probe interfacial characteristics of fibronectin fragment FNIII
8-14 and full-length fibronectin (FN) on CH3 -, OH-, COOH-, and NH2 -terminated alkane-thiol self-assembled monolayers (SAMs). Force-distance curves acquired between hexahistidine-tagged FNIII8-14 immobilised on trisNTA-Ni2+ functionalized AFM cantilevers and the OH and COOH SAM surfaces were predominantly 'loop-like' (76% and 94% respectively), suggesting domain unfolding and preference for 'end-on' oriented binding, while those generated with NH2 and CH3 SAMs were largely 'mixed type' (81% and 86%, respectively) commensurate with unravelling and desorption, and 'side-on' binding. Time-dependent binding of FN to SAM-coated QCM crystals occurred in at least two phases: initial rapid coverage over the first 5 min; and variably diminishing adsorption thereafter (5-70 min). Loading profiles and the final hydrated surface concentrations reached (~ 950, ~ 1200, ~ 1400, ~ 1500 ng cm-2 for CH3 , OH, COOH and NH2 SAMs) were consistent with: space-filling 'side-on' orientation and unfolding on CH3 SAM; greater numbers of FN molecules arranged 'end-on' on OH and especially COOH SAMs; and initial 'side-on' contact, followed by either (1) gradual tilting to a space-saving 'end-on' configuration, or (2) bi-/multi-layer adsorption on NH2 SAM.- Published
- 2020
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41. Strong toll-like receptor responses in cystic fibrosis patients are associated with higher lung function.
- Author
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Kosamo S, Hisert KB, Dmyterko V, Nguyen C, Black RA, Holden TD, Radella F, Cotten PA, Goss CH, Aitken ML, and Wurfel MM
- Subjects
- Adult, Armadillo Domain Proteins metabolism, Correlation of Data, Cystic Fibrosis Transmembrane Conductance Regulator genetics, Cytoskeletal Proteins metabolism, Down-Regulation, Female, Humans, Intracellular Signaling Peptides and Proteins metabolism, Male, Proto-Oncogene Proteins c-akt metabolism, United States epidemiology, Cystic Fibrosis diagnosis, Cystic Fibrosis epidemiology, Cystic Fibrosis immunology, Cystic Fibrosis physiopathology, Gene Expression Profiling methods, Immunity, Innate immunology, Respiratory Function Tests methods, Toll-Like Receptors agonists, Toll-Like Receptors immunology
- Abstract
Background: Cystic fibrosis (CF) airways disease varies widely among patients with identical cystic fibrosis transmembrane conductance regulator (CFTR) genotypes. Robust airway inflammation is thought to be deleterious in CF; inter-individual variation in Toll-like receptor (TLR)-mediated innate immune inflammatory responses (TMIIR) might account for a portion of the phenotypic variation. We tested if TMIIR in people with CF are different than those of healthy controls, and whether higher TMIIR in people with CF are associated with reduced lung function., Methods: We cultured whole blood from clinically stable subjects with CF (n = 76) and healthy controls (n = 45) with TLR agonists, and measured cytokine production and expression of TLR-associated genes. We tested for differences in TLR-stimulated cytokine levels between subjects with CF and healthy subjects, and for associations between cytokine and gene expression levels with baseline lung function (forced expiratory volume in one second percent predicted (FEV
1 %)) and decline in FEV1 % over time., Results: TMIIR in blood from subjects with CF were lower than in healthy controls. Expression of TLR regulators SARM1, TOLLIP, and AKT1 were downregulated in CF. In subjects with CF we found that lower TLR4-agonist-induced IL-8 was associated with lower FEV1 % at enrollment (p<0.001) and with greater five year FEV1 % decline (p<0.001)., Conclusions: TMIIR were lower in people with CF relative to healthy controls; however, unexpectedly, greater whole blood TMIIR were positively associated with lung function in people with CF. These findings suggest a complex interaction between inflammation and disease in people with CF., Competing Interests: Declaration of Competing Interest The authors report no conflicts of interest., (Copyright © 2019. Published by Elsevier B.V.)- Published
- 2020
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42. Low-Cost Eye Phantom for Stereophotogrammetry-Based Optic Nerve Head Topographical 3D Imaging.
- Author
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Coghill I, Black RA, Livingstone IAT, and Giardini ME
- Subjects
- Humans, Imaging, Three-Dimensional, Phantoms, Imaging, Photogrammetry, Glaucoma, Optic Disk
- Abstract
Glaucoma is the second leading cause of blindness globally. Stereophotogrammetry-based optic nerve head topographical imaging systems could potentially allow for objective glaucoma assessment in settings where technologies such as optical coherence tomography and the Heidelberg Retinal Tomograph are prohibitively expensive. In the development of such systems, eye phantoms are invaluable tools for both system calibration and performance evaluation. Eye phantoms developed for this purpose need to replicate the optical configuration of the eye, the related causes of measurement artefacts, and give the possibility to present to the imaging system the targets required for system calibration. The phantoms in the literature that show promise of meeting these requirements rely on custom lenses to be fabricated, making them very costly. Here, we propose a low-cost eye phantom comprising a vacuum formed cornea and commercially available stock bi-convex lens, that is optically similar to a gold-standard reference wide-angle schematic eye model and meets all the compliance and configurability requirements for use with stereo-photogrammetry-based ONH topographical imaging systems. Moreover, its modular design, being fabricated largely from 3D-printed components, lends itself to modification for other applications. The use of the phantom is successfully demonstrated in an ONH imager.
- Published
- 2020
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43. The impact of cigarette and e-cigarette use history on transition patterns: a longitudinal analysis of the population assessment of tobacco and health (PATH) study, 2013-2015.
- Author
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Wei L, Muhammad-Kah RS, Hannel T, Pithawalla YB, Gogova M, Chow S, and Black RA
- Subjects
- Adolescent, Adult, Age Factors, Cohort Studies, Electronic Nicotine Delivery Systems, Female, Humans, Longitudinal Studies, Male, Middle Aged, United States epidemiology, Young Adult, Cigarette Smoking epidemiology, Vaping epidemiology
- Abstract
Background: Population models have been developed to evaluate the impact of new tobacco products on the overall population. Reliable input parameters such as longitudinal tobacco use transitions are needed to quantify the net population health impact including the number of premature deaths prevented, additional life years, and changes in cigarette smoking prevalence., Methods: This secondary analysis assessed transition patterns from PATH wave 1 (2013-14) to wave 2 (2014-15) among adult exclusive cigarette smokers, exclusive e-cigarette users, and dual users. Transition probabilities were calculated by taking into account factors including cigarette smoking and e-cigarette use histories and experimental or established use behaviors. Multinomial logistic regression models were constructed to further evaluate factors associated with transition patterns., Results: Differential transition probabilities emerged among study subgroups when taking into account cigarette smoking and e-cigarette use histories and experimental or established use behaviors. For example, overall 45% of exclusive e-cigarette users in wave 1 continued using e-cigarettes exclusively in wave 2. However, we observed approximately 11 to 14% of wave 1 exclusive experimental e-cigarette users continued to use e-cigarette exclusively in wave 2, compared to about 62% of exclusive established e-cigarette users. The history of cigarette smoking and e-cigarette use is another important factor associated with transition patterns. Among experimental e-cigarette users, 7.5% of individuals without a history of cigarette smoking transitioned to exclusive cigarette smoking, compared to 30% of individuals with a history of cigarette smoking. Additionally, 1.3% of exclusive cigarette smokers in wave 1 transitioned to exclusive e-cigarette use, with the highest transition probability (3.7%) observed in the established cigarette smoker with a history of e-cigarette use subgroup., Conclusions: Product use histories and current use behaviors are important factors influencing transitions between product use states. Given that experimental users' transition behaviors may be more variable and more influenced by tobacco use history, long-term predictions made by population models could be improved by the use of transition probabilities from established users. As transition patterns might be changing over time, long-term transition patterns can be examined through analysis of future waves of PATH data.
- Published
- 2020
- Full Text
- View/download PDF
44. Development of a Bioactive Polymeric Drug Eluting Coronary Stent Coating Using Electrospraying.
- Author
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McKittrick CM, Cardona MJ, Black RA, and McCormick C
- Subjects
- Animals, Cell Survival, Cells, Cultured, Drug Delivery Systems, Drug Liberation, Endothelial Cells drug effects, Polymers chemistry, Sirolimus chemistry, Swine, Technology, Pharmaceutical, Drug-Eluting Stents, Polymers administration & dosage, Sirolimus administration & dosage
- Abstract
Drug-eluting stents are now routinely used in the treatment of acute coronary syndromes caused by coronary artery disease. Whilst the sustained release of anti-proliferative drugs from these devices has greatly reduced the need for repeat revascularisation procedures, this approach is not suitable for all patients and appears to delay regrowth of the endothelium, necessitating the use of prolonged dual anti-platelet therapy. Although the development of more advanced stent platforms and drug coatings has produced modest improvements in performance, these devices have not fully addressed the limitations experienced with their first-generation counterparts. In the present study, we developed a novel stent coating that provides controlled sirolimus release from a bioactive polymer (accelerate™ AT) that has previously been shown to support endothelial cell growth in vitro. A bespoke electrospray deposition process provided control over the coating thickness, surface roughness, drug load, and release kinetics. The resultant optimised coating combines rapid release of an anti-proliferative agent from a bioactive polymer coating that promotes re-endothelialisation, thereby offering potential protection against in-stent restenosis and thrombosis. This novel, dual-action coating therefore has significant therapeutic potential, with the enhanced control of drug load and release kinetics offered by electrospray deposition also opening up opportunities for more personalised treatment approaches. Further development and evaluation of these technologies in vitro and in vivo is therefore warranted.
- Published
- 2020
- Full Text
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45. Leaf: an open-source, model-agnostic, data-driven web application for cohort discovery and translational biomedical research.
- Author
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Dobbins NJ, Spital CH, Black RA, Morrison JM, de Veer B, Zampino E, Harrington RD, Britt BD, Stephens KA, Wilcox AB, Tarczy-Hornoch P, and Mooney SD
- Subjects
- Databases as Topic, Humans, Internet, Unified Medical Language System, Data Warehousing, Information Storage and Retrieval methods, Translational Research, Biomedical, User-Computer Interface, Vocabulary, Controlled
- Abstract
Objective: Academic medical centers and health systems are increasingly challenged with supporting appropriate secondary use of clinical data. Enterprise data warehouses have emerged as central resources for these data, but often require an informatician to extract meaningful information, limiting direct access by end users. To overcome this challenge, we have developed Leaf, a lightweight self-service web application for querying clinical data from heterogeneous data models and sources., Materials and Methods: Leaf utilizes a flexible biomedical concept system to define hierarchical concepts and ontologies. Each Leaf concept contains both textual representations and SQL query building blocks, exposed by a simple drag-and-drop user interface. Leaf generates abstract syntax trees which are compiled into dynamic SQL queries., Results: Leaf is a successful production-supported tool at the University of Washington, which hosts a central Leaf instance querying an enterprise data warehouse with over 300 active users. Through the support of UW Medicine (https://uwmedicine.org), the Institute of Translational Health Sciences (https://www.iths.org), and the National Center for Data to Health (https://ctsa.ncats.nih.gov/cd2h/), Leaf source code has been released into the public domain at https://github.com/uwrit/leaf., Discussion: Leaf allows the querying of single or multiple clinical databases simultaneously, even those of different data models. This enables fast installation without costly extraction or duplication., Conclusions: Leaf differs from existing cohort discovery tools because it does not specify a required data model and is designed to seamlessly leverage existing user authentication systems and clinical databases in situ. We believe Leaf to be useful for health system analytics, clinical research data warehouses, precision medicine biobanks, and clinical studies involving large patient cohorts., (© The Author(s) 2019. Published by Oxford University Press on behalf of the American Medical Informatics Association.)
- Published
- 2020
- Full Text
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46. Effect of prepartum exercise on lying behavior, labor length, and cortisol concentrations.
- Author
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Black RA and Krawczel PD
- Subjects
- Animals, Cattle blood, Female, Lactation, Parity, Parturition, Postpartum Period, Pregnancy, Pregnancy, Animal blood, Rest, Cattle physiology, Hydrocortisone blood, Physical Conditioning, Animal, Pregnancy, Animal physiology
- Abstract
The objective of this study was to assess the effect of exercise and pasture turnout on lying behavior, labor length, and cortisol concentrations around the time of parturition in dairy cows. Twenty-nine primiparous and 31 multiparous, pregnant, nonlactating Holstein (n = 58) and Jersey × Holstein cross (n = 2) dairy cows were assigned to control (n = 20), exercise (n = 20), or pasture (n = 20) treatments at dry-off using rolling enrollment. Control cows remained in the dry cow group pen. Exercise cows were removed from the dry cow group pen 5 times per week and walked for 1.4 ± 0.1 h at 1.88 ± 0.58 km/h. Pasture cows were moved to an outdoor paddock 5 times per week for 1.8 ± 0.3 h/d. Cows were housed in deep-bedded sand freestalls in a naturally ventilated, 4-row freestall barn. Cows were moved into maternity pens on the day of projected calving or when cows displayed signs that calving was imminent (restlessness, raised or lifted tail, ruptured amniotic sac, or swollen vulva), and treatments were discontinued. Cameras continuously recorded cows from entry into the pen until farm staff noted a calf, and one observer continuously watched video for two visually observable periods throughout the calving process: time from initial observation of amniotic sac to initial observation of calf's feet, and time from initial observation of calf's feet to full expulsion of calf. Assisted calvings were excluded. Accelerometers were attached to the rear fetlocks of cows 3 d before dry-off and removed 14 d postpartum. Activity was summarized by day for the 7 d before and after delivery time recorded from video observation into lying time (hours per day), lying bout frequency (bouts per day), lying bout duration (minutes per bout), and steps (number per day). Plasma total cortisol concentration was measured on d 0 and 3 postpartum and determined by a radioimmunoassay procedure using a commercially available kit. Data were analyzed using mixed linear model. During calving, time from appearance of the amniotic sac to appearance of the calf's feet was longer for pasture cows compared with control. Control cows engaged in fewer lying bouts and less overall lying time compared with pasture and exercise cows. Cortisol concentrations were higher on the day of calving compared with 3 d later, regardless of treatment. Understanding the effects of lying alterations around calving and increases in labor period length may allow for physical activity recommendations for late-gestation dairy cows., (Copyright © 2019 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
47. 40th Anniversary Issue: Reflections on papers from the archive on "Biomaterials and their biomedical applications".
- Author
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Black RA and Houston G
- Subjects
- Anniversaries and Special Events, Biocompatible Materials, Biomedical Research, Publications
- Published
- 2019
- Full Text
- View/download PDF
48. 40th Anniversary Issue: Reflections on papers from the archive on "Rehabilitation Engineering".
- Author
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Black RA and Houston G
- Subjects
- Anniversaries and Special Events, Engineering, Publications, Rehabilitation
- Published
- 2019
- Full Text
- View/download PDF
49. 40th Anniversary Issue (25 Years of Medical Engineering & Physics).
- Author
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Black RA
- Subjects
- Anniversaries and Special Events, Engineering, Periodicals as Topic, Physics
- Published
- 2019
- Full Text
- View/download PDF
50. 40th Anniversary Issue: Reflections on papers from the archive on "Mechanobiology".
- Author
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Black RA and Houston G
- Subjects
- Biomechanical Phenomena, Anniversaries and Special Events, Cell Biology, Mechanical Phenomena, Publications
- Published
- 2019
- Full Text
- View/download PDF
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