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"Olsen, A."
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Trends in Global Tropospheric Ozone Inferred from a Composite Record of TOMS/OMI/MLS/OMPS Satellite Measurements and the MERRA-2 GMI Simulation
Past studies have suggested that ozone in the troposphere has increased globally throughout much of the 20th century due to increases in anthropogenic emissions and transport. We show, by combining satellite measurements with a chemical transport model, that during the last four decades tropospheric ozone does indeed indicate increases that are global in nature, yet still highly regional. Satellite ozone measurements from Nimbus-7 and Earth Probe Total Ozone Mapping Spectrometer (TOMS) are merged with ozone measurements from the Aura Ozone Monitoring Instrument/Microwave Limb Sounder (OMI/MLS) to determine trends in tropospheric ozone for 1979–2016. Both TOMS (1979–2005) and OMI/MLS (2005–2016) depict large increases in tropospheric ozone from the Near East to India and East Asia and further eastward over the Pacific Ocean. The 38-year merged satellite record shows total net change over this region of about +6 to +7 Dobson units (DU) (i.e., ∼15 %–20 % of average background ozone), with the largest increase (∼4 DU) occurring during the 2005–2016 Aura period. The Global Modeling Initiative (GMI) chemical transport model with time-varying emissions is used to aid in the interpretation of tropospheric ozone trends for 1980–2016. The GMI simulation for the combined record also depicts the greatest increases of +6 to +7 DU over India and East Asia, very similar to the satellite measurements. In regions of significant increases in tropospheric column ozone (TCO) the trends are a factor of 2–2.5 larger for the Aura record when compared to the earlier TOMS record; for India and East Asia the trends in TCO for both GMI and satellite measurements are ∼+3 DU decade(exp −1) or greater during 2005–2016 compared to about +1.2 to +1.4 DU decade(exp −1) for 1979–2005. The GMI simulation and satellite data also reveal a tropospheric ozone increases in ∼+4 to +5 DU for the 38-year record over central Africa and the tropical Atlantic Ocean. Both the GMI simulation and satellite-measured tropospheric ozone during the latter Aura time period show increases of ∼+3 DU decade−1 over the N Atlantic and NE Pacific.
Journal Article
World flutelore : folktales, myths, and other stories of magical flute power
In many places around the world, flutes and the sounds of flutes are powerful magical forces for seduction and love, protection, vegetal and human fertility, birth and death, and other aspects of human and non-human behaviour. This book explores the cultural significance of flutes, flute playing, and flute players from around the world as interpreted from folktales, myths, and other stories - in a word, 'flutelore'.
Book
Metabolic syndrome, metabolic comorbid conditions and risk of early-onset colorectal cancer
ObjectiveFactors that lead to metabolic dysregulation are associated with increased risk of early-onset colorectal cancer (CRC diagnosed under age 50). However, the association between metabolic syndrome (MetS) and early-onset CRC remains unexamined.DesignWe conducted a nested case–control study among participants aged 18–64 in the IBM MarketScan Commercial Database (2006–2015). Incident CRC was identified using pathologist-coded International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes, and controls were frequency matched. MetS was defined as presence of ≥3 conditions among obesity, hypertension, hyperlipidaemia and hyperglycaemia/type 2 diabetes, based on ICD-9-CM and use of medications. Multivariable logistic regressions were used to estimate ORs and 95% CIs.ResultsMetS was associated with increased risk of early-onset CRC (n=4673; multivariable adjusted OR 1.25; 95% CI 1.09 to 1.43), similar to CRC diagnosed at age 50–64 (n=14 928; OR 1.21; 95% CI 1.15 to 1.27). Compared with individuals without a metabolic comorbid condition, those with 1, 2 or ≥3 conditions had a 9% (1.09; 95% CI 1.00 to 1.17), 12% (1.12; 95% CI 1.01 to 1.24) and 31% (1.31; 95% CI 1.13 to 1.51) higher risk of early-onset CRC (ptrend <0.001). No associations were observed for one or two metabolic comorbid conditions and CRC diagnosed at age 50–64. These positive associations were driven by proximal (OR per condition 1.14; 95% CI 1.06 to 1.23) and distal colon cancer (OR 1.09; 95% CI 1.00 to 1.18), but not rectal cancer (OR 1.03; 95% CI 0.97 to 1.09).ConclusionsMetabolic dysregulation was associated with increased risk of early-onset CRC, driven by proximal and distal colon cancer, thus at least in part contribute to the rising incidence of early-onset CRC.
Journal Article
Structure of the human lipid exporter ABCB4 in a lipid environment
ABCB4 is an ATP-binding cassette transporter that extrudes phosphatidylcholine into the bile canaliculi of the liver. Its dysfunction or inhibition by drugs can cause severe, chronic liver disease or drug-induced liver injury. We determined the cryo-EM structure of nanodisc-reconstituted human ABCB4 trapped in an ATP-bound state at a resolution of 3.2 Å. The nucleotide binding domains form a closed conformation containing two bound ATP molecules, but only one of the ATPase sites contains bound Mg2+. The transmembrane domains adopt a collapsed conformation at the level of the lipid bilayer, but we observed a large, hydrophilic and fully occluded cavity at the level of the cytoplasmic membrane boundary, with no ligand bound. This indicates a state following substrate release but prior to ATP hydrolysis. Our results rationalize disease-causing mutations in human ABCB4 and suggest an ‘alternating access’ mechanism of lipid extrusion, distinct from the ‘credit card swipe’ model of other lipid transporters.Cryo-EM structure of human transporter ABCB4 that extrudes phosphatidylcholine into the bile canaliculi suggests an ‘alternating access’ mechanism of lipid extrusion, distinct from the ‘credit card swipe’ model of other lipid transporters.
Journal Article
Trends and drivers in global surface ocean pH over the past 3 decades
We report global long-term trends in surface ocean pH using a new pH data set computed by combining fCO2 observations from the Surface Ocean CO2 Atlas (SOCAT) version 2 with surface alkalinity estimates based on temperature and salinity. Trends were determined over the periods 1981–2011 and 1991–2011 for a set of 17 biomes using a weighted linear least squares method. We observe significant decreases in surface ocean pH in ~70% of all biomes and a mean rate of decrease of 0.0018 ± 0.0004 yr−1 for 1991–2011. We are not able to calculate a global trend for 1981–2011 because too few biomes have enough data for this. In half the biomes, the rate of change is commensurate with the trends expected based on the assumption that the surface ocean pH change is only driven by the surface ocean CO2 chemistry remaining in a transient equilibrium with the increase in atmospheric CO2. In the remaining biomes, deviations from such equilibrium may reflect that the trend of surface ocean fCO2 is not equal to that of the atmosphere, most notably in the equatorial Pacific Ocean, or may reflect changes in the oceanic buffer (Revelle) factor. We conclude that well-planned and long-term sustained observational networks are key to reliably document the ongoing and future changes in ocean carbon chemistry due to anthropogenic forcing.
Journal Article
Who donates in campaigns? : the importance of message, messenger, medium, and structure
\"Campaigns cost money--a lot of money. In 2012, Mitt Romney, Barack Obama, and their allies collectively spent more than $2 billion in the race for the presidency, with both sides spending more than $1 billion. Looking just at money raised by the campaigns from individual donors, the Obama campaign outraised the Republicans by over $500 million in 2008 and over $250 million in 2012.1\"-- Provided by publisher.
Book
Clostridium difficile—Associated Disease in a Setting of Endemicity: Identification of Novel Risk Factors
Background.Previous studies of risk factors for Clostridium difficile—associated disease (CDAD) have been limited by small sample sizes and case-control study designs. Many of these studies were performed during outbreaks of CDAD. Colonization pressure and use of fluoroquinolones, vancomycin, and gastric acid suppressors have not been fully evaluated as risk factors for CDAD. The purpose of this study was to determine risk factors for endemic CDAD, including CDAD pressure, a modified version of colonization pressure. Methods.We performed a retrospective cohort study of 36,086 patients admitted to Barnes-Jewish Hospital (St. Louis, MO) during the period from 1 January 2003 through 31 December 2003. Administrative, laboratory, and pharmacy data were collected from electronic hospital databases. Colonization pressure was measured through a surrogate variable (i.e., CDAD pressure). Multivariable pooled logistic regression models were used to evaluate independent risk factors for CDAD. Results.The analysis included 382 CDAD case patient admissions and 35,704 non—case patient admissions. Significant independent risk factors for CDAD included increasing age, admission(s) in the previous 60 days, hypoalbuminemia, leukemia and/or lymphoma, mechanical ventilation, and receipt of antimotility drugs, histamine-2 blockers, proton pump inhibitors, intravenous vancomycin, fluoroquinolones, and first-, third-, or fourth-generation cephalosporins. Increasing CDAD pressure was a strong risk factor for CDAD (for a CDAD pressure >1.4, the odds ratio was 4.0; 95% confidence interval, 2.9–5.6). Receipt of metronidazole was protective against CDAD (odds ratio, 0.5; 95% confidence interval, 0.3–0.6). Conclusions.This study identified the previously underrecognized CDAD risk factors of CDAD pressure and vancomycin. More studies are needed to evaluate the relationship between CDAD, these risk factors, and use of gastric acid suppressors and fluoroquinolones.
Journal Article