Evolution of tropical land temperature across the last glacial termination

The tropicalWest Pacific hosts the warmest part of the surface ocean and has a considerable impact on the global climate system. Reconstructions of past temperature in this region can elucidate climate connections between the tropics and poles and the sensitivity of tropical temperature to greenhouse forcing. However, existing data are equivocal and reliable information from terrestrial archives is particularly sparse. Here we constrain themagnitude and timing of land temperature change in the tropical West Pacific across the last deglaciation using an exceptionally precise paleothermometer applied to a well-dated stalagmite from Northern Borneo. We show that the cave temperature increased by 4.4 ± 0.3 °C (2 SEM) from the Last Glacial Maximum to the Holocene, amounting to 3.6 ± 0.3 °C (2 SEM) when correcting for sea-level induced cave altitude change. The warming closely follows atmospheric CO2 and Southern Hemisphere warming. This contrasts with hydroclimate, as reflected by dripwater δ18O, which responds to Northern Hemisphere cooling events in the form of prominent drying, while temperature was rising. Our results thus show a close response of tropical temperature to greenhouse forcing, independent of shifts in the tropical circulation patterns.Research Council of NorwayEuropean Commission 262353/F20 European Research Council (ERC) European Commission 101001957National Science Foundation (NSF) 0645291Juan de la Cierva Fellowship IJC2019-040065-

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

Characterization and Correction of Evaporative Artifacts in Speleothem Fluid Inclusion Isotope Analyses as Applied to a Stalagmite From Borneo

Abstract Fluid inclusion water isotope measurements in speleothems have great potential for paleoclimate studies as they enable the reconstruction of precipitation dynamics and land temperatures. Several previous observations, however, suggest that inclusion waters do not always reflect the isotopic composition of surface precipitation. In such cases, dripwaters are thought to be modified by evaporation in the cave environment that results in more positive δ2H and δ18O values and shallow δ2H/δ18O slopes. Although evaporation can occur in cave systems, water can also be lost to evaporation during analysis but before water extraction. Here, we examine the likelihood of this possibility with a stalagmite from Borneo. We demonstrate that many samples lose water, and that water loss is controlled by the type and size of inclusions. With multiple replicate measurements of coeval samples, we calculate an evaporative δ2H/δ18O slope of 1.0 ± 0.6 (2SE). This value is consistent with model predictions of evaporative fractionation at high analytical temperature and low humidity. Finally, we propose a method to correct for this effect. We find that fluid–calcite δ18O paleotemperatures calculated with corrected δ18O data show excellent agreement with recent microthermometry temperature estimates for Borneo, supporting the validity of our approach and implying limited stalagmite δ18O disequilibrium variations. Corrected fluid inclusion δ18O and δ2H values follow the expected hydroclimate response of Borneo to periods of reduced Atlantic Ocean meridional overturning circulation. Our results suggest that careful petrographic examination and multiple replicate measurements are necessary for reliable paleoclimate reconstructions with speleothem fluid inclusion water isotopes

Evolution of tropical land temperature across the last glacial termination

The tropical West Pacific hosts the warmest part of the surface ocean and has a considerable impact on the global climate system. Reconstructions of past temperature in this region can elucidate climate connections between the tropics and poles and the sensitivity of tropical temperature to greenhouse forcing. However, existing data are equivocal and reliable information from terrestrial archives is particularly sparse. Here we constrain the magnitude and timing of land temperature change in the tropical West Pacific across the last deglaciation using an exceptionally precise paleothermometer applied to a well-dated stalagmite from Northern Borneo. We show that the cave temperature increased by 4.4 ± 0.3 °C (2 SEM) from the Last Glacial Maximum to the Holocene, amounting to 3.6 ± 0.3 °C (2 SEM) when correcting for sea-level induced cave altitude change. The warming closely follows atmospheric CO and Southern Hemisphere warming. This contrasts with hydroclimate, as reflected by drip water δO, which responds to Northern Hemisphere cooling events in the form of prominent drying, while temperature was rising. Our results thus show a close response of tropical temperature to greenhouse forcing, independent of shifts in the tropical circulation patterns.This work has been funded by the Norwegian Research Council (grant no. 262353/F20 to A.N.M.) and the European Research Council (grant no. 101001957 to A.N.M.). Sample collection has been funded by NSF award no.0645291 to K.M.C. A.F. acknowledges support from Juan de la Cierva Fellowship (IJC2019-040065-I)

Diameter stenosis at follow-up according to plasma concentrations of asymmetric dimethylarginine and trimethyllysine^a.

<p>DS, Diameter Stenosis; ADMA, asymmetric dimethylarginine; TML, trimethyllysine.</p>a<p>Non-parametric linear quantile mixed-effects models of diameter stenosis at follow-up using Laplace distribution.</p>b<p>Effect estimate given as regression coefficient (95% confidence interval) and p-value for change in percentage point diameter stenosis.</p>c<p>The fixed effect in this model is ADMA and DS measured at baseline while the random effect is the clustering of arterial segments within a single patient. Estimates are presented as median (95% confidence interval). Standard error is estimated using bootstrapping.</p>d<p>The fixed effect in this model is TML and DS measured at baseline while the random effect is the clustering of arterial segments within a single patient. Estimates are presented as median (95% confidence interval). Standard error is estimated using bootstrapping.</p>e<p>The fixed effect in this model is DS measured at baseline, follow-up time in days, presence of diabetes, randomization (folic acid/B₁₂ vs no folic acid/B₁₂) status at baseline, plasma TML at baseline, smoking status, age, gender, plasma ADMA at baseline, systolic blood pressure, body mass index, kidney function, apolioprotein B100 and C-reactive protein while the random effect is the clustering of arterial segments within a single patient. Standard error is estimated using bootstrapping.</p

Baseline Characteristics and Laboratory Findings in Patients with Angiographic Coronary Lesions (n = 183).

<p>For continuous variables, mean and standard deviation or median and interquartile range within each group is calculated. Student's T-test or Mann-Withney U-test was used to compare the two groups. For categorical variables, number and percentage is presentend and a Chi square test was used to compare the four groups. Fisher's exact test was used when appropriate. All biochemical parameteres are prestented as median (interquartile range). FA, folic acid (0.8 mg); B₁₂, vitamin B₁₂ (0.4 mg); B₆, vitamin B₆ (40 mg); PCI, percutaneous coronary intervention; CABG, coronary artery bypass graft surgery; NSTACS, composite syndrom consisting of acute coronary syndrome including both ST-elevated and non-ST-elevated myocardial infarction; AMI, acute myocardial infarction; CHD, coronary heart disease; LMS, left main stem; LAD, left anterior descending artery; CX, circumflex branch; RCA, right coronary artery; ACE, Angiotensin I converting enzyme; LDL, low-density lipoprotein; HDL, high-density lipoprotein; eGFR, estimated glomerular filtration rate; ADMA, asymmetric dimethylarginine. Percentages may not add up due to rounding of numbers.</p>a<p>Ejection fraction was measured during ventriculography for the majority of the patients. When this was not performed, ultrasonic echocardiography was used.</p>b<p>A prior diagnosis of any peripheral or cerebrovascular disease.</p>c<p>Medication at discharge.</p>d<p>Including ARB - angiotensin receptor blockers.</p

Grayscale IVUS and Virtual Histology of TCFA.

<p>A thin cap fibroatheroma (asterisk) in the proximal left anterior descending coronary artery of one of the study patients. The left panel shows an intravascular ultrasound radiofrequency image which is subsequently used to make the virtual histology image in the right panel. Green is fibrous tissue, yellow is fibro-fatty, red is necrotic core and white is calcified tissue. </p

MCP-1 and Presence of Occult Thin-Cap Fibroatheroma at VH–IVUS Study Inclusion.

<p>Cumulative distribution frequency plots of Monocyte Chemotactic Protein-1 (MCP-1) in patients with (solid line) and without (dashed line) Virtual Histology Thin-Cap Fibroatheroma (VH-TCFA).</p