Intercomparison of carbonate chemistry measurements on a cruise in northwestern European shelf seas

Four carbonate system variables were measured in surface waters during a cruise aimed at investigating ocean acidification impacts traversing northwestern European shelf seas in the summer of 2011. High-resolution surface water data were collected for partial pressure of carbon dioxide (pCO2; using two independent instruments) and pH using the total pH scale (pHT), in addition to discrete measurements of total alkalinity and dissolved inorganic carbon. We thus overdetermined the carbonate system (four measured variables, two degrees of freedom), which allowed us to evaluate the level of agreement between the variables on a cruise whose main aim was not intercomparison, and thus where conditions were more representative of normal working conditions. Calculations of carbonate system variables from other measurements generally compared well with direct observations of the same variables (Pearson’s correlation coefficient always greater than or equal to 0.94; mean residuals were similar to the respective accuracies of the measurements). We therefore conclude that four of the independent data sets of carbonate chemistry variables were of high quality. A diurnal cycle with a maximum amplitude of 41 μatm was observed in the difference between the pCO2 values obtained by the two independent analytical pCO2 systems, and this was partly attributed to irregular seawater flows to the equilibrator and partly to biological activity inside the seawater supply and one of the equilibrators. We discuss how these issues can be addressed to improve carbonate chemistry data quality on future research cruises

Characterization of meta-Cresol Purple for spectrophotometric pH measurements in saline and hypersaline media at sub-zero temperatures

Accurate pH measurements in polar waters and sea ice brines require pH indicator dyes characterized at near-zero and below-zero temperatures and high salinities. We present experimentally determined physical and chemical characteristics of purified meta-Cresol Purple (mCP) pH indicator dye suitable for pH measurements in seawater and conservative seawater-derived brines at salinities (S) between 35 and 100 and temperatures (T) between their freezing point and 298.15 K (25 °C). Within this temperature and salinity range, using purified mCP and a novel thermostated spectrophotometric device, the pH on the total scale (pHT) can be calculated from direct measurements of the absorbance ratio R of the dye in natural samples as pHT=−log(kT2e2)+log(R−e11−Re3e2) Based on the mCP characterization in these extended conditions, the temperature and salinity dependence of the molar absorptivity ratios and − log(kT2e2) of purified mCP is described by the following functions: e1 = −0.004363 + 3.598 × 10−5T, e3/e2 = −0.016224 + 2.42851 × 10−4T + 5.05663 × 10−5(S − 35), and − log(kT2e2) = −319.8369 + 0.688159 S −0.00018374 S2 + (10508.724 − 32.9599 S + 0.059082S2) T−1 + (55.54253 − 0.101639 S) ln T −0.08112151T. This work takes the characterisation of mCP beyond the currently available ranges of 278.15 K ≤ T ≤ 308.15 K and 20 ≤ S ≤ 40 in natural seawater, thereby allowing high quality pHT measurements in polar systems

Socioeconomic position, lifestyle habits and biomarkers of epigenetic aging: A multi-cohort analysis

Differences in health status by socioeconomic position (SEP) tend to be more evident at older ages, suggesting the involvement of a biological mechanism responsive to the accumulation of deleterious exposures across the lifespan. DNA methylation (DNAm) has been proposed as a biomarker of biological aging that conserves memory of endogenous and exogenous stress during life.We examined the association of education level, as an indicator of SEP, and lifestyle-related variables with four biomarkers of age-dependent DNAm dysregulation: the total number of stochastic epigenetic mutations (SEMs) and three epigenetic clocks (Horvath, Hannum and Levine), in 18 cohorts spanning 12 countries.The four biological aging biomarkers were associated with education and different sets of risk factors independently, and the magnitude of the effects differed depending on the biomarker and the predictor. On average, the effect of low education on epigenetic aging was comparable with those of other lifestyle-related risk factors (obesity, alcohol intake), with the exception of smoking, which had a significantly stronger effect.Our study shows that low education is an independent predictor of accelerated biological (epigenetic) aging and that epigenetic clocks appear to be good candidates for disentangling the biological pathways underlying social inequalities in healthy aging and longevity

Socioeconomic position, lifestyle habits and biomarkers of epigenetic aging: A multi-cohort analysis

Differences in health status by socioeconomic position (SEP) tend to be more evident at older ages, suggesting the involvement of a biological mechanism responsive to the accumulation of deleterious exposures across the lifespan. DNA methylation (DNAm) has been proposed as a biomarker of biological aging that conserves memory of endogenous and exogenous stress during life. We examined the association of education level, as an indicator of SEP, and lifestyle-related variables with four biomarkers of age-dependent DNAm dysregulation: the total number of stochastic epigenetic mutations (SEMs) and three epigenetic clocks (Horvath, Hannum and Levine), in 18 cohorts spanning 12 countries. The four biological aging biomarkers were associated with education and different sets of risk factors independently, and the magnitude of the effects differed depending on the biomarker and the predictor. On average, the effect of low education on epigenetic aging was comparable with those of other lifestyle-related risk factors (obesity, alcohol intake), with the exception of smoking, which had a significantly stronger effect. Our study shows that low education is an independent predictor of accelerated biological (epigenetic) aging and that epigenetic clocks appear to be good candidates for disentangling the biological pathways underlying social inequalities in healthy aging and longevity

Measuring pH in low ionic strength glacial meltwaters using ion selective field effect transistor (ISFET) technology

Measuring pH in glacial meltwaters is challenging, because they are cold, remote, subject to freeze‐thaw cycles and have low ionic strength. Traditional methods often perform poorly there; glass electrodes have high drift and long response times, and spectrophotometric techniques are unpractical in cold, remote environments. Ion selective field effect transistor (ISFET) sensors are a promising alternative, proven in marine and industrial applications. We assess the suitability of two models of ISFET, the Honeywell Durafet and Campbell Scientific Sentron, for use in glacial melt through a series of lab and field experiments. The sensors have excellent tolerance of freeze‐thaw and minimal long‐term drift, with the Durafet experiencing less drift than the Sentron model. They have predictable response to temperature, although the Durafet housing causes some lag during rapid cycling, and the impact of stirring is an order of magnitude less than that of glass electrodes. At low ionic strength ( 7 with consistent diurnal cycles from the very first meltwater flows. We recommend that ISFET sensors are used to assess the pH of glacial meltwater, since their tolerance is significantly better than alternative methods: the Durafet is accurate to ± 0.2 pH when waters are > 1 mmol L−1 ionic strength, and ± 0.3 pH at < 1 mmol L−1

Socioeconomic position, lifestyle habits and biomarkers of epigenetic aging: A multi-cohort analysis

Differences in health status by socioeconomic position (SEP) tend to be more evident at older ages, suggesting the involvement of a biological mechanism responsive to the accumulation of deleterious exposures across the lifespan. DNA methylation (DNAm) has been proposed as a biomarker of biological aging that conserves memory of endogenous and exogenous stress during life. We examined the association of education level, as an indicator of SEP, and lifestyle-related variables with four biomarkers of age-dependent DNAm dysregulation: the total number of stochastic epigenetic mutations (SEMs) and three epigenetic clocks (Horvath, Hannum and Levine), in 18 cohorts spanning 12 countries. The four biological aging biomarkers were associated with education and different sets of risk factors independently, and the magnitude of the effects differed depending on the biomarker and the predictor. On average, the effect of low education on epigenetic aging was comparable with those of other lifestyle-related risk factors (obesity, alcohol intake), with the exception of smoking, which had a significantly stronger effect. Our study shows that low education is an independent predictor of accelerated biological (epigenetic) aging and that epigenetic clocks appear to be good candidates for disentangling the biological pathways underlying social inequalities in healthy aging and longevity

Différences d’accès à Internet et de recherche d’informations en santé via Internet selon le trouble psychiatrique

International audienceBackground: Internet has become a major tool for patients to search for health-related information and to communicate on health. We currently lack data on how patients with psychiatric disorders access and use Internet to search for information on their mental health. This study aimed to assess, in patients followed up for a psychiatric disorder (schizophrenia, bipolar disorder, mood and anxiety disorder, substance-related and addictive disorders and eating disorders), what was the prevalence rate for Internet access and use, the expectations and needs regarding the use of Internet to search for mental-health information depending on the psychiatric disorder. Methods: We conducted this cross-sectional study between May 2013 and July 2013 in 648 patients followed up in psychiatry in 8 Hospitals from the Region Centre, France. We used multivariate logistic regression adjusted for age, gender, socio-educational level and professional status to compare use, expectations and needs regarding internet-based information about the patient's psychiatric disorder (65items self-administered questionnaire) between the different psychiatric disorders. We identified different clusters of patients using multiple correspondence analysis and ascending hierarchical classification. Results: Although 65.6% of our population accessed Internet at home, prevalence rate for Internet access varied depending on the type of psychiatric disorder and was much more related to lower access to computer and lower revenues than to a lack of interest to Internet. Most of the patients who used internet were interested in having access to reliable Internet-based information on their health (76.8%), and most used Internet to search for Internet based health-information on their psychiatric disorder (58.8%). We found important differences in terms of expectations and needs depending on the patient's psychiatric disorder (e.g., higher interest in Internet-based information in patients with bipolar disorder, substance-related and addictive disorders and eating disorders). We identified three clusters: younger patients with depressive or anxiety disorders and higher internet access and internet use; older patients with low socio-economical status and low internet access and internet use; patients who were followed up for a long time for schizophrenia, with low internet access and internet use. Conclusion: Patients with psychiatric disorders reported average use, needs and expectations for Internet-based health information comparable to the overall population. Hovewer, internet use, needs and expectations for Internet-based mental health information differs between patients depending on their psychiatric disorder. Internet-based information and communication for mental health should be fitted for each psychiatric disorder.Position du problème : Si internet est désormais un outil d’information et de communication incontournable en santé, nous manquons de données quant à l’usage d’internet à des fins de santé chez les patients suivis en psychiatrie. L’objectif de ce travail était de déterminer, chez les patients suivis en psychiatrie, quels étaient leurs usages, attentes et ressentis vis-à-vis de l’internet-santé en fonction du trouble psychiatrique (schizophrénie, trouble bipolaire, troubles anxieux/dépressifs, addictions, troubles du comportement alimentaire). Méthodes : Une enquête transversale a été réalisée auprès de 648 patients suivis en psychiatrie entre mai 2013 et juillet 2013 dans 8 hôpitaux de la région Centre. Nous avons comparé l’usage, les attentes et les ressentis vis-à-vis de l’internet-santé (auto-questionnaire en 65 items) selon la pathologie psychiatrique par des régressions logistiques multivariées ajustées sur les variables âge, sexe, niveau d’étude et statut d’emploi. Des profils d’utilisateurs ont été dressés via une analyse des correspondances multiples suivie d’un classification ascendante hiérarchique. Résultats : Si 65,6% des patients avaient accès à internet à domicile, il existait des différences d’accès selon la pathologie, en lien avec des facteurs matériels (faibles revenus, absence d’accès à internet) plutôt qu’avec un manque d’intérêt. Si la majorité des patients usagers d’internet étaient intéressés par des sites d’information fiables sur leur pathologie (76,8%) et avaient utilisé internet pour s’informer sur leur pathologie (58,8%), il existait des différences importantes d’usage, d’attentes et de ressentis selon le trouble psychiatrique (intérêt plus marqué pour les patients souffrant de trouble bipolaire, d’addiction et de trouble du comportement alimentaire). Trois profils de patients ont été identifiés : patients jeunes avec troubles dépressifs ou anxieux et accès à internet ; patients âgés de faible niveau socio-économique et peu d’accès à internet ; patients schizophrènes suivis de longue date avec peu d’accès à internet. Conclusion : Les patients souffrant de troubles psychiatriques ont en moyenne des usages en matière d’information et de communication sur leur santé via internet comparables aux autres patients. Toutefois, les usages, attentes et perceptions des patients diffèrent selon le trouble psychiatrique, nécessitant d’adapter les moyens d’information et de communication sur internet en fonction de chaque pathologie

Bordetella holmesii bacteremia in a renal transplant recipient: emergence of a new pathogen.

International audienceBordetella holmesii is a gram-negative rod that was initially identified in 1995. It causes bacteremia, pneumonia, and endocarditis mostly in patients with anatomical or functional asplenia. We report here, to the best of our knowledge, the first case of B. holmesii bacteremia in a renal transplant recipient following rituximab therapy for recurrence of membranoproliferative glomerulonephritis

Characterization of meta-Cresol Purple for spectrophotometric pH measurements in saline and hypersaline media at sub-zero temperatures

Accurate pH measurements in polar waters and sea ice brines require pH indicator dyes characterized at near-zero and below-zero temperatures and high salinities. We present experimentally determined physical and chemical characteristics of purified meta-Cresol Purple (mCP) pH indicator dye suitable for pH measurements in seawater and conservative seawater-derived brines at salinities (S) between 35 and 100 and temperatures (T) between their freezing point and 298.15 K (25 °C). Within this temperature and salinity range, using purified mCP and a novel thermostated spectrophotometric device, the pH on the total scale (pHT) can be calculated from direct measurements of the absorbance ratio R of the dye in natural samples aspHT=−log(kT2e2)+log(R−e11−Re3e2)Based on the mCP characterization in these extended conditions, the temperature and salinity dependence of the molar absorptivity ratios and − log(kT2e2)of purified mCP is described by the following functions: e1 = −0.004363 + 3.598 × 10−5T, e3/e2 = −0.016224 + 2.42851 × 10−4T + 5.05663 × 10−5(S − 35), and − log(kT2e2) = −319.8369 + 0.688159 S −0.00018374 S2 + (10508.724 − 32.9599 S + 0.059082S2) T−1 + (55.54253 − 0.101639 S) ln T −0.08112151T. This work takes the characterisation of mCP beyond the currently available ranges of 278.15 K ≤ T ≤ 308.15 K and 20 ≤ S ≤ 40 in natural seawater, thereby allowing high quality pHT measurements in polar systems