Dissolution of calcium carbonate: observations and model results in the North Atlantic

International audienceWe investigate the significance of in situ dissolution of calcium carbonate above its saturation horizons. The study relies on observations from the open subpolar North Atlantic [sNA] and on a 3-D biogeochemical model. The sNA is particularly well suited for observation-based detections of in situ, i.e. shallow depth CaCO3 dissolution [SDCCD] as it is a region of high CaCO3 production, deep CaCO3 saturation horizons, and precisely-defined pre-formed alkalinity. Based on the analysis of a comprehensive alkalinity data set we find that SDCCD does not appear to be a significant process in the open sNA. The results from the model support the observational findings and do not indicate a significant need of SDCCD to explain observed patterns of alkalinity in the North Atlantic. Instead our investigation points to the importance of mixing processes for the redistribution of alkalinity from dissolution of CaCO3 from below its saturation horizons. However, mixing has recently been neglected for a number of studies that called for SDCCD in the sNA and on global scale

Dissolution of calcium carbonate: observations and model results in the subpolar North Atlantic

We investigate the significance of in situ dissolution of calcium carbonate above its saturation horizons using observations from the open subpolar North Atlantic [sNA] and to a lesser extent a 3-D biogeochemical model. The sNA is particularly well suited for observation-based detections of in situ, i.e. shallow-depth CaCO3 dissolution [SDCCD] as it is a region of high CaCO3 production, deep CaCO3 saturation horizons, and precisely-defined pre-formed alkalinity. Based on the analysis of a comprehensive alkalinity data set we find that SDCCD does not appear to be a significant process in the open sNA. The results from the model support the observational findings by indicating that there is not a significant need of SDCCD to explain observed patterns of alkalinity in the North Atlantic. Instead our investigation points to the importance of mixing processes for the redistribution of alkalinity from dissolution of CaCO3 from below its saturation horizons. However, mixing has recently been neglected for a number of studies that called for SDCCD in the sNA and on global scale

Impacts of Atmospheric Nitrogen Deposition on Surface Waters of the Western North Atlantic Mitigated by Multiple Feedbacks

The impacts of atmospheric nitrogen deposition (AND) on the chlorophyll and nitrogen dynamics of surface waters in the western North Atlantic (25 degrees N-45 degrees N, 65 degrees W-80 degrees W) are examined with a biogeochemical ocean model forced with a regional atmospheric chemistry model (Community Multiscale Air Quality, CMAQ). CMAQ simulations with year-specific emissions reveal the existence of a hot spot of AND over the Gulf Stream. The impact of the hot spot on the oceanic biogeochemistry is mitigated in three ways by physical and biogeochemical processes. First, AND significantly contributes to surface oceanic nitrogen concentrations only during the summer period, when the stratification is maximal and the background nitrogen inventories are minimal. Second, the increase in summer surface nitrate concentrations is accompanied by a reduction in upward nitrate diffusion at the base of the surface layer. This negative feedback partly cancels the nitrogen enrichment from AND. Third, gains in biomass near the surface force a shoaling of the euphotic layer and a reduction of about 5% in deep primary production and biomass on the continental shelf. Despite these mitigating processes, the impacts of AND remain substantial. AND increases surface nitrate concentrations in the Gulf Stream region by 14% during the summer (2% on average over the year). New primary production increases by 22% in this region during summer (8% on average). Although these changes may be difficult to distinguish from natural variability in observations, the results support the view that AND significantly enhances local carbon export

Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1: A Link Between Insulin and Lipid Metabolism

OBJECTIVE—Liver-specific inactivation of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) by a dominant-negative transgene (l-SACC1 mice) impaired insulin clearance, caused insulin resistance, and increased hepatic lipogenesis. To discern whether this phenotype reflects a physiological function of CEACAM1 rather than the effect of the dominant-negative transgene, we characterized the metabolic phenotype of mice with null mutation of the Ceacam1 gene (Cc1−/−)

Intravenous erythropoietin in patients with ST-segment elevation myocardial infarction - REVEAL: A randomized controlled trial

Context: Acute ST-segment elevation myocardial infarction (STEMI) is a leading cause of morbidity and mortality. In experimental models of MI, erythropoietin reduces infarct size and improves left ventricular (LV) function. Objective: To evaluate the safety and efficacy of a single intravenous bolus of epoetin alfa in patients with STEMI. Design, Setting, and Patients: A prospective, randomized, double-blind, placebo-controlled trial with a dose-escalation safety phase and a single dose (60 000 U of epoetin alfa) efficacy phase; the Reduction of Infarct Expansion and Ventricular Remodeling With Erythropoietin After Large Myocardial Infarction (REVEAL) trial was conducted at 28 US sites between October 2006 and February 2010, and included 222 patients with STEMI who underwent successful percutaneous coronary intervention (PCI) as a primary or rescue reperfusion strategy. Intervention: Participants were randomly assigned to treatment with intravenous epoetin alfa or matching saline placebo administered within 4 hours of reperfusion. Main Outcome Measure: Infarct size, expressed as percentage of LV mass, assessed by cardiac magnetic resonance (CMR) imaging performed 2 to 6 days after study medication administration (first CMR) and again 12±2 weeks later (second CMR). Results: In the efficacy cohort, the infarct size did not differ between groups on either the first CMR scan (n=136; 15.8% LV mass [95% confidence interval {CI}, 13.3-18.2% LV mass] for the epoetin alfa group vs 15.0% LV mass [95% CI, 12.6-17.3% LV mass] for the placebo group; P=.67) or on the second CMR scan (n=124; 10.6% LV mass [95% CI, 8.4-12.8% LV mass] vs 10.4% LV mass [95% CI, 8.5-12.3% LV mass], respectively; P=.89). In a prespecified analysis of patients aged 70 years or older (n=21), the mean infarct size within the first week (first CMR) was larger in the epoetin alfa group (19.9% LV mass; 95% CI, 14.0-25.7% LV mass) than in the placebo group (11.7% LV mass; 95% CI, 7.2-16.1% LV mass) (P=.03). In the safety cohort, of the 125 patients who received epoetin alfa, the composite outcome of death, MI, stroke, or stent thrombosis occurred in 5 (4.0%; 95% CI, 1.31%-9.09%) but in none of the 97 who received placebo (P=.04). Conclusions: In patients with STEMI who had successful reperfusion with primary or rescue PCI, a single intravenous bolus of epoetin alfa within 4 hours of PCI did not reduce infarct size and was associated with higher rates of adverse cardiovascular events. Subgroup analyses raised concerns about an increase in infarct size among older patients. Trial Registration: clinicaltrials.gov Identifier: NCT00378352. ©2011 American Medical Association. All rights reserved

Physical and mental health comorbidity is common in people with multiple sclerosis: nationally representative cross-sectional population database analysis

<b>Background</b> Comorbidity in Multiple Sclerosis (MS) is associated with worse health and higher mortality. This study aims to describe clinician recorded comorbidities in people with MS. <p></p> <b>Methods</b> 39 comorbidities in 3826 people with MS aged ≥25 years were compared against 1,268,859 controls. Results were analysed by age, gender, and socioeconomic status, with unadjusted and adjusted Odds Ratios (ORs) calculated using logistic regression. <p></p> <b>Results</b> People with MS were more likely to have one (OR 2.44; 95% CI 2.26-2.64), two (OR 1.49; 95% CI 1.38-1.62), three (OR 1.86; 95% CI 1.69-2.04), four or more (OR 1.61; 95% CI 1.47-1.77) non-MS chronic conditions than controls, and greater mental health comorbidity (OR 2.94; 95% CI 2.75-3.14), which increased as the number of physical comorbidities rose. Cardiovascular conditions, including atrial fibrillation (OR 0.49; 95% CI 0.36-0.67), chronic kidney disease (OR 0.51; 95% CI 0.40-0.65), heart failure (OR 0.62; 95% CI 0.45-0.85), coronary heart disease (OR 0.64; 95% CI 0.52-0.71), and hypertension (OR 0.65; 95% CI 0.59-0.72) were significantly less common in people with MS. <p></p> <b>Conclusion</b> People with MS have excess multiple chronic conditions, with associated increased mental health comorbidity. The low recorded cardiovascular comorbidity warrants further investigation

Contracting for the unknown and the logic of innovation

This paper discusses the components of contracts adequatefor governing innovation, and their microfoundations in the logic of innovative decision processes. Drawing on models of discovery and design processes, distinctive logical features of innovative decision making are specified and connected to features of contracts that can sustain innovation processes and do not fail under radical uncertainty. It is argued that if new knowledge is to be generated under uncertainty and risk, 'relational contracts', as usually intended, are not enough and a more robust type of contracting is needed and it is actually often used: formal constitutional contracts that associate resources, leave their uses rationally unspecified, but exhaustively specify the assignment of residual decision rights and other property rights, and the decision rules to be followed in governance. The argument is supported by an analysis of a large international database on the governance of multi-party projects in discovery-intensive and design-intensive industries

How brains make decisions

This chapter, dedicated to the memory of Mino Freund, summarizes the Quantum Decision Theory (QDT) that we have developed in a series of publications since 2008. We formulate a general mathematical scheme of how decisions are taken, using the point of view of psychological and cognitive sciences, without touching physiological aspects. The basic principles of how intelligence acts are discussed. The human brain processes involved in decisions are argued to be principally different from straightforward computer operations. The difference lies in the conscious-subconscious duality of the decision making process and the role of emotions that compete with utility optimization. The most general approach for characterizing the process of decision making, taking into account the conscious-subconscious duality, uses the framework of functional analysis in Hilbert spaces, similarly to that used in the quantum theory of measurements. This does not imply that the brain is a quantum system, but just allows for the simplest and most general extension of classical decision theory. The resulting theory of quantum decision making, based on the rules of quantum measurements, solves all paradoxes of classical decision making, allowing for quantitative predictions that are in excellent agreement with experiments. Finally, we provide a novel application by comparing the predictions of QDT with experiments on the prisoner dilemma game. The developed theory can serve as a guide for creating artificial intelligence acting by quantum rules.Comment: Latex file, 20 pages, 3 figure