Anthropogenic carbon in the eastern South Pacific Ocean

International audienceWe present results from the BIOSOPE cruise in the eastern South Pacific Ocean. In particular, we present estimates of the anthropogenic carbon CantTrOCA distribution in this area using the TrOCA method recently developed by Touratier and Goyet (2004a, b) and Touratier et al. (2007). We study the distribution of this anthropogenic carbon taking into account of the hydrodynamic characteristics of this region. We then compare these results with earlier estimates in nearby areas of the anthropogenic carbon as well as other anthropogenic tracer (CFC-11). The highest concentrations of CantTrOCA are located around 13° S 132° W and 32° S 91° W, and their concentrations are larger than 80 µmol kg-1 and 70 µmol kg-1, respectively. The lowest concentrations were observed below 800 m depths (=2 µ mol kg-1) and at the Oxygen Minimum Zones (OMZ), mainly around 140° W (-1). The comparison with earlier work in nearby areas provides a general trend and indicates that the results presented here are in general agreement with previous knowledge. This work further improves our understanding on the penetration of anthropogenic carbon in the eastern Pacific Ocean

Reductions of Hidden Information Sources

In all but special circumstances, measurements of time-dependent processes reflect internal structures and correlations only indirectly. Building predictive models of such hidden information sources requires discovering, in some way, the internal states and mechanisms. Unfortunately, there are often many possible models that are observationally equivalent. Here we show that the situation is not as arbitrary as one would think. We show that generators of hidden stochastic processes can be reduced to a minimal form and compare this reduced representation to that provided by computational mechanics--the epsilon-machine. On the way to developing deeper, measure-theoretic foundations for the latter, we introduce a new two-step reduction process. The first step (internal-event reduction) produces the smallest observationally equivalent sigma-algebra and the second (internal-state reduction) removes sigma-algebra components that are redundant for optimal prediction. For several classes of stochastic dynamical systems these reductions produce representations that are equivalent to epsilon-machines.Comment: 12 pages, 4 figures; 30 citations; Updates at http://www.santafe.edu/~cm

Fungal vaccines and immunotherapeutics: current concepts and future challenges

Purpose of review The remarkable advances in modern medicine have paradoxically resulted in a rapidly expanding population of immunocompromised patients displaying extreme susceptibility to life-threatening fungal infections. There are currently no licensed vaccines, and the prophylaxis and therapy of fungal infections in at-risk individuals remains challenging, contributing to undesirable mortality and morbidity rates. The design of successful antifungal preventive approaches has been hampered by an insufficient understanding of the dynamics of the host-fungus interaction and the mechanisms that underlie heterogenous immune responses to vaccines and immunotherapy. Recent findings Recent advances in proteomics and glycomics have contributed to the identification of candidate antigens for use in subunit vaccines, novel adjuvants, and delivery systems to boost the efficacy of protective vaccination responses that are becoming available, and several targets are being exploited in immunotherapeutic approaches. Summary We review some of the emerging concepts as well as the inherent challenges to the development of fungal vaccines and immunotherapies to protect at-risk individuals.ThisworkwassupportedbytheNorthernPortugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER) (NORTE-01-0145-FEDER-000013), and the Fundação para a Ciência e Tecnologia (FCT) (contracts IF/00735/ 2014 to A.C., and SFRH/BPD/96176/2013 to C.C).info:eu-repo/semantics/publishedVersio

Seeds of Amazonian Fabaceae as a source of new lectins

Seeds from fifty native Amazonian Fabaceae species (representing subfamilies Caesalpinioideae, Mimosoideae and Faboideae) were screened for the presence of new lectins. Their crude protein extracts were assayed for hemagglutinating activity (HA). The protein fractions of Anadenanthera peregrina, Dimorphandra caudata, Ormosia lignivalvis and Swartzia laevicarpa exhibited HA, and this activity was inhibited by galactose or lactose but not by glucose or mannose. The crude extract of S. laevicarpa exhibited HA activity only after ion exchange chromatography, and its lectin was further purified by affinity chromatography on immobilized lactose. Despite the large number of lectins that have been reported in leguminous plants, this is the first description of lectins in the genera Anadenanthera, Dimorphandra and Ormosia. The study of lectins from these genera and from Swartzia will contribute to the understanding of the evolutionary relationships of legume lectins in terms of their protein processing properties and structures

Epidemiology and patterns of tracheostomy practice in patients with acute respiratory distress syndrome in ICUs across 50 countries

Background: To better understand the epidemiology and patterns of tracheostomy practice for patients with acute respiratory distress syndrome (ARDS), we investigated the current usage of tracheostomy in patients with ARDS recruited into the Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG-SAFE) study. Methods: This is a secondary analysis of LUNG-SAFE, an international, multicenter, prospective cohort study of patients receiving invasive or noninvasive ventilation in 50 countries spanning 5 continents. The study was carried out over 4 weeks consecutively in the winter of 2014, and 459 ICUs participated. We evaluated the clinical characteristics, management and outcomes of patients that received tracheostomy, in the cohort of patients that developed ARDS on day 1-2 of acute hypoxemic respiratory failure, and in a subsequent propensity-matched cohort. Results: Of the 2377 patients with ARDS that fulfilled the inclusion criteria, 309 (13.0%) underwent tracheostomy during their ICU stay. Patients from high-income European countries (n = 198/1263) more frequently underwent tracheostomy compared to patients from non-European high-income countries (n = 63/649) or patients from middle-income countries (n = 48/465). Only 86/309 (27.8%) underwent tracheostomy on or before day 7, while the median timing of tracheostomy was 14 (Q1-Q3, 7-21) days after onset of ARDS. In the subsample matched by propensity score, ICU and hospital stay were longer in patients with tracheostomy. While patients with tracheostomy had the highest survival probability, there was no difference in 60-day or 90-day mortality in either the patient subgroup that survived for at least 5 days in ICU, or in the propensity-matched subsample. Conclusions: Most patients that receive tracheostomy do so after the first week of critical illness. Tracheostomy may prolong patient survival but does not reduce 60-day or 90-day mortality. Trial registration: ClinicalTrials.gov, NCT02010073. Registered on 12 December 2013

Identifying associations between diabetes and acute respiratory distress syndrome in patients with acute hypoxemic respiratory failure: an analysis of the LUNG SAFE database

Background: Diabetes mellitus is a common co-existing disease in the critically ill. Diabetes mellitus may reduce the risk of acute respiratory distress syndrome (ARDS), but data from previous studies are conflicting. The objective of this study was to evaluate associations between pre-existing diabetes mellitus and ARDS in critically ill patients with acute hypoxemic respiratory failure (AHRF). Methods: An ancillary analysis of a global, multi-centre prospective observational study (LUNG SAFE) was undertaken. LUNG SAFE evaluated all patients admitted to an intensive care unit (ICU) over a 4-week period, that required mechanical ventilation and met AHRF criteria. Patients who had their AHRF fully explained by cardiac failure were excluded. Important clinical characteristics were included in a stepwise selection approach (forward and backward selection combined with a significance level of 0.05) to identify a set of independent variables associated with having ARDS at any time, developing ARDS (defined as ARDS occurring after day 2 from meeting AHRF criteria) and with hospital mortality. Furthermore, propensity score analysis was undertaken to account for the differences in baseline characteristics between patients with and without diabetes mellitus, and the association between diabetes mellitus and outcomes of interest was assessed on matched samples. Results: Of the 4107 patients with AHRF included in this study, 3022 (73.6%) patients fulfilled ARDS criteria at admission or developed ARDS during their ICU stay. Diabetes mellitus was a pre-existing co-morbidity in 913 patients (22.2% of patients with AHRF). In multivariable analysis, there was no association between diabetes mellitus and having ARDS (OR 0.93 (0.78-1.11); p = 0.39), developing ARDS late (OR 0.79 (0.54-1.15); p = 0.22), or hospital mortality in patients with ARDS (1.15 (0.93-1.42); p = 0.19). In a matched sample of patients, there was no association between diabetes mellitus and outcomes of interest. Conclusions: In a large, global observational study of patients with AHRF, no association was found between diabetes mellitus and having ARDS, developing ARDS, or outcomes from ARDS. Trial registration: NCT02010073. Registered on 12 December 2013