Search

We determined the nutritional adequacy and overall quality of the diets of adult patients with eosinophilic esophagitis (EoE). Dietary intakes stratified by sex and age were compared to Dietary Reference Values (DRV). Overall diet quality was assessed by two independent Diet-Quality-Indices scores, the PANDiet and DHD-index, and compared to age- and gender-matched subjects from the general population. Lastly, food and nutrient intakes of EoE patients were compared to intakes of the general population. Saturated fat intake was significantly higher and dietary fiber intake significantly lower than the DRV in both males and females. In males, the DRV were not reached for potassium, magnesium, selenium, and vitamins A and D. In females, the DRV were not reached for iron, sodium, potassium, selenium, and vitamins A, B2, C and D. EoE patients had a significantly lower PANDiet and DHD-index compared to the general population, although the relative intake (per 1000 kcal) of vegetables/fruits/olives was significantly higher (yet still up to 65% below the recommended daily amounts) and alcohol intake was significantly lower compared to the general Dutch population. In conclusion, the composition of the habitual diet of adult EoE patients has several pro-inflammatory and thus unfavorable immunomodulatory properties, just as the general Dutch population, and EoE patients had lower overall diet quality scores than the general population. Due to the observational character of this study, further research is needed to explore whether this contributes to the development and progression of EoE.

The comments raised by Paumard et al. (2020) led us to identify some pitfalls and limitations regarding the use of seismic geomorphology and seismic stratigraphy for paleoenvironmental reconstructions of carbonate systems and to add some clarifications on the Teillet et al. (2020a) depositional model. The comparison of the paleoenvironmental predictions by Paumard et al. (2017) with core data revealed severe inconsistencies which are due to the diachronous nature of the seismic horizon from which attribute map was computed and to the omission of fluid effects on seismic expression. In addition, detailed well-to-seismic ties revealed also that chronostratigraphic well-correlations using seismic data should be considered with caution when vertical seismic resolution is reduced (>20 m). Regarding the development pattern of the Yadana platform, we consider that the platform backstepping evidenced from seismic is not is in contradiction with the lack of deepening upward trend on platform top revealed by cores. The existence of a euphotic carbonate factory in Yadana cannot be ruled out. From the available dataset such a putative carbonate production would be reduced and/or exported out of the western Yadana platform. Finally, we propose a general workflow for better integrating seismic reflection patterns and attributes in the paleoenvironmental reconstruction of strongly diagenetized carbonate reservoirs which are imaged by low to moderate resolution (>20 m) seismic datasets.

International audience

Calcification of microbial mats adds significant amounts of calcium carbonate to primary coral reef structures that stabilizes and binds reef frameworks. Previous studies have shown that the distribution and thicknesses of late Quaternary microbial crusts have responded to changes in environmental parameters such as seawater pH, carbonate saturation state, and sediment and nutrient fluxes. However, these studies are few and limited in their spatio-temporal coverage. In this study, we used 3D and 2D examination techniques to investigate the spatio-temporal distribution of microbial crusts and their responses to environmental changes in Integrated Ocean Drilling Program (IODP) Expedition 325 (Great Barrier Reef Environmental Changes) fossil reef cores that span 30 to 10 ka at two locations on the GBR reef margin. Our GBR microbialite record was then combined with a meta-analysis of 17 other reef records to assess global scale changes in microbialite development (i.e., presence/absence, thickness) over the same period. The 3D results were compared with 2D surface area measurements to assess the accuracy of 2D methodology. The 2D technique represents an efficient and accurate proxy for the 3D volume of reef framework components within the bounds of uncertainty (average: 9.45 ± 4.5%). We found that deep water reef frameworks were most suitable for abundant microbial crust development. Consistent with a previous Exp. 325 study (Braga et al., 2019), we also found that crust ages were broadly coeval with coralgal communities in both shallow water and fore-reef settings. However, in some shallow water settings they also occur as the last reef framework binding stage, hundreds of years after the demise of coralgal communities. Lastly, comparisons of crust thickness with changes in environmental conditions between 30 and 10 ka, show a temporal correlation with variations in partial pressure of CO2 (pCO2), calcite saturation state (Ωcalcite), and pH of seawater, particularly during the past ~15 kyr, indicating that these environmental factors likely played a major role in microbialite crust development in the GBR. This supports the view that microbialite crust development can be used as an indicator of ocean acidification.

International audience

International audience; Field observations and hydrogeological drilling investigations carried out in Reunion and Mauritius Islands revealed marine coral-rich carbonate deposits interbedded with or trapped into lavas flows and (or) volcanic detritus in coastal sites. The times of deposition of these carbonates are inferred mainly from K/Ar dating and relative age estimates of associated volcanic rocks. In Reunion, three coral deposits were found beneath the western slopes of the older Piton des Neiges shield volcano. These were dated at 0.28–0.27 million years (Ma), 0.25 Ma, and about 37,000 years respectively, indicating that marine deposition occurred during Marine Isotope Stage (MIS) 8 low stand, MIS 7.5 high stand, and MIS 3.2 low stand. On Mauritius, seven marine carbonate units were identified, located in western and northern areas. The oldest are believed to be late Miocene (older than 5 Ma) to early Pliocene (4–4.5 Ma) in age. The younger were assigned to MIS 11 (0.44–0.35 Ma), MIS 9–8 (older than 0.26 Ma), and MISs 7.5 and 5.5 respectively. While the Piton des Neiges shield would have remained relatively stable since the earlier eruptive phases, Mauritius is shown to have experienced low rates of subsidence (0.015–0.033 mm/year). Identification and point-counting of the main skeletal components—including foraminiferal assemblages—from each carbonate unit, combined with statistical treatment (principal component analysis) of the relevant dataset, allowed different biological associations to be delineated, typified respectively by alcyonarians, ectoprocts, corals, coralline algae and foraminifera. By analogy with the compositional patterns of modern reefal sediments, these associations are shown to be referable to the outer-reef zones (i.e. lower fore-reef and upper fore-reef) and reef-crest to reef-flat zones. By contrast, in Reunion, coral gravels and boulders deposited during MIS 7.5 are interpreted as coastal, storm-generated sediments. The lack of recognized backreef deposits in drillholes in either Reunion or Mauritius suggest that the reef tracts represented may not have possessed well-differentiated backreef environments, but developed in the form of coralgal carpets or narrow fringing reefs such as those present along the west side of Reunion and western and northern Mauritius.

International audience; A method of quantitative sequence stratigraphy based on stratigraphic forward modeling is tested on carbonate sedimentary systems (CSSs), especially on shallow-water carbonate platforms. Unless clear three-dimensional (3-D) and two-dimensional stratigraphic geometries crop out or are imaged by seismic data, 3-D carbonate sequence stratigraphic architectures are reconstructed assuming that one single factor representing changes in the ratio of the accommodation rate and the sedimentation rate (A'/S') through time can describe complex 3-D carbonate stratigraphic architectures at the basin scale. In this work, it is demonstrated that despite using a unique accommodation curve and a time-constant carbonate production, the preservation of theoretical A'/S', regarded as the fundamental parameter of sequence stratigraphy, is incomplete and spatially variable throughout a simple carbonate platform stratigraphic architecture. The apparent A'/S' sequence stratigraphic parameters preserved in the stratigraphic records are distinguished from the actual A'/S' parameters that control the stratigraphic response of CSSs. During overall accommodation increase, prograding and retrograding geometries can be time equivalent whereas coeval shallowing-and deepening-upward sequences may form. Apparent A'/S' spatial trends in one dimension are not consistently correlated between proximal and distal locations and do not typify specific stratigraphic architectures. This is the direct consequence of the spatial and synchronous variations in carbonate production rates along the platform profile. These results indicate that the construction of carbonate sedimentary piles, including carbonate reservoirs, cannot be simply based on standard sequence stratigraphic correlations of sparse and distant locations along platform-to-slope sedimentary profiles. Limitations of sequence stratigraphic correlations and uncertainties of A'/S' rates are addressed from an actual CSS case study (Lower Cretaceous Urgonian platform, southern Provence, France). A quantitative carbonate sequence stratigraphic workflow based on stratigraphic forward modeling is proposed.

International audience; The Western Indian Ocean results from a complex geological history, implying both plate motion since about 180 million years and volcanic hot-spot activity since about 68 million years. This region exhibits a myriad of islands different in nature and origin, including continental remnants (Madagascar, the granitic Seychelles), high volcanic islands (Reunion, Mauritius, Rodrigues, the Comoros), high- and low-lying carbonate reef platforms (the carbonate Seychelles, the French Scattered Island Group, Agalega Islands) and a few submerged reef banks (Geyser, Nazareth, Saya de Malha). This region contains all known types of reefs-fringing, barrier, atoll, platform and bank. The data about reef development history over the Quaternary were gained mainly from two distinct sources: boreholes and emerged outcrops. Reef drilling indicates that modern reefs started regionally to grow from about 10,000-9600 years BP. Rates of vertical reef accretion ranges from 0.2 to about 10 mm/year according to exposure and shape of coral builders. The sea-level curves, reconstructed from vertical reef-accretion and lagoon-deposition curves, express a rapid rise in sea level at rates averaging 6 mm/year between 10,000 and 7500-7000 years BP, with a stabilization at the present position around 2500-3000 years BP. There are significant variations in the composition and distribution of dominant reef-building coral assemblages and facies (framework versus detritus) according to exposure to wave energy. Frameworks composed of robust coral branching assemblages-mainly Acropora robusta, A. humilis groups; Isopora palifera-dominate in higher energy settings, while those with domal and tabular branching forms-mainly Porites, various faviids, Acropora hyacinthus group-are best represented in lower-energy to protected environments. Detritus-reefs are best developed in sheltered sites. The recent contribution of some dominant coral species in modern WIO reefs seem to have resulted from their delayed arrival in the region as controlled by the regional prevailing surface circulation-South Equatorial Current and Agulhas Current-and/or by the competency period of their larvae. Coral-based, geochemical records suggest that, during the mid Holocene, the seasonal variability of sea surface temperatures was lower than today. The reconstruction of the WIO Pleistocene reef history is chiefly based on a limited number of exposed reef remains deposited during the last interglacial MIS 5.5 stage (129,000-125,000 years BP), at present culminating at elevations ranging from - 20 to + 9 m with respect to present mean sea level. Such differences in elevation can be explained by a differential tectonic behaviour of reef-bearing substrates, from stable continental areas to subsiding volcanic islands. The existence of older reef generations (Plio-Pleistocene) was identified from coral-rich inclusions trapped into pyroclastites of Comoro volcanoes.

The development history of an oligo-mesophotic, early Miocene, isolated carbonate system (>160 m in thickness), forming the uppermost part of the Oligo-Miocene Yadana buildup (northern Andaman Sea), has been evidenced from the integration of sedimentological core studies from 4 wells (cumulated core length: 343 m), well correlations, seismic interpretation and analysis of the ecological requirements of the main skeletal components. Three types of carbonate factory operated on the top of the platform, depending on water-depth, turbidity and nutrient level: (1) a scleractinian factory developing under mesophotic conditions during periods of high particulate organic matter supplies, (2) an echinodermal factory occupying dysphotic to aphotic area of the platform coevally with the scleractinian factory, (3) a large benthic foraminiferal-coralline algal factories prevailing under oligo-mesophotic and oligo-mesotrophic conditions. The limited lateral changes in facies between wells, together with the seismic expression of the Yadana buildup, suggest deposition on a flat-topped shelf. Carbonate production and accumulation on the Yadana platform was mainly controlled by light penetration, nutrient content and hydrodynamic conditions. Scleractinian-rich facies resulted from transport of coral pieces derived from mesophotic environments (mounds?) and deposited in deeper, low light , mud-rich environments in which lived abundant communities of suspension feeders such as ophiuroids. Changes in monsoonal intensity, terrestrial runoff from the Irrawaddy River, upwelling currents and internal waves activity during the early Miocene are likely responsible for significant variations in water turbidity and nutrient concentration in the Andaman Sea, thus promoting the development of an oligo-mesophotic, incipiently drowned platform.

moleculARweb (https://molecularweb.epfl.ch) began as a website for education and outreach in chemistry and structural biology through augmented reality (AR) content that runs in the web browsers of regular devices like smartphones, tablets, and computers. Here we present two evolutions of moleculARweb’s Virtual Modeling Kits (VMK), tools where users can build and view molecules, and explore their mechanics, in 3D AR by handling the molecules in full 3D with custom-printed cube markers (VMK 2.0) or by moving around a simulated scene with mouse or touch gestures (VMK 3.0). Upon simulation the molecules experience visually realistic torsions, clashes, and hydrogen-bonding interactions that the user can manually switch on and off to explore their effects. Moreover, by manually tuning a fictitious temperature the users can accelerate conformational transitions or 'freeze' specific conformations for careful inspection in 3D. Even some phase transitions and separations can be simulated. We here showcase these and other features of the new VMKs connecting them to possible specific applications to teaching and self-learning of concepts from general, organic, biological and physical chemistry; and in assisting with small tasks in molecular modelling for research. Last, in a short discussion section we overview what future developments are needed for the 'dream tool' for the future of chemistry education and work.

Data on the mineral status of infants with cow's milk allergy (CMA) consuming an amino acid-based formula (AAF) have not been published. The present study aims to assess mineral status of term infants age 0 to 8 months diagnosed with CMA receiving an AAF for 16 weeks. Serum concentrations of calcium, phosphorus, chloride, sodium, potassium, magnesium, and ferritin were determined in 82 subjects at baseline and in 66 subjects after 16 weeks on AAF using standard methods and evaluated against age-specific reference ranges. In addition to this, individual estimated energy and mineral intakes were compared to Adequate Intakes defined by the European Food Safety Authority and the US Institute of Medicine. The results of this study show that the AAF was effective in providing an adequate mineral status in infants with CMA. The vast majority of infants aged 0 to 6 months (formula only) and aged 6 to 12 months (formula and complementary foods) had adequate mineral intakes.

Dans l’archipel volcanique des Marquises, les îles du Nord (Eiao, Ua Uka et Nuku Hiva) possèdent des dépôts carbonatés cimentés, formant des ilots ou des reliefs adossés à la côte, localisés le long des secteurs méridionaux et orientaux. Atteignant localement une altitude supérieure à 200 m, ces dépôts présentent la forme de dôme aplati, de croissant ou de cône d’accumulation. Essentiellement composés de fragments d’organismes marins à squelette calcaire, accumulés en strates plurimétriques finement litées à disposition oblique, ces dépôts ont été interprétés comme étant d’anciennes plages ultérieurement soulevées. De nouvelles analyses géomorphologiques, lithostratigraphiques (identification des structures internes, évaluation des dimensions et des pendages des corps sédimentaires) et sédimentologiques (granulométrie, identification des cimentations précoces) révèlent que ces formations carbonatées ont été élaborées à partir de sables moyens à très fins isométriques, accumulés selon des angles de repos fréquemment supérieurs à 30° et finalement cimentés en milieu sub-aérien. Ces caractéristiques militent en faveur d’une origine éolienne, ce qui conduit à considérer ces dépôts comme des paléo-dunes ou éolianites littorales, façonnées par l’action des vents dominants des secteurs est-sud-est (alizés), à partir d’épandages sédimentaires marins alors émergés, au cours d’une ou plusieurs chutes du niveau marin entre le Pléistocène moyen et récent. In the volcanic Marquesas archipelago, the Northern islands (Eiao, Ua Uka and Nuku Hiva) exhibit cemented carbonate deposits as islets or coastal reliefs, located along their southern and eastern areas. Locally lying at up to 200 m in elevation, these deposits occur in the form of flatted dome, crescent or collecting cone. Chiefly made up of detritus from marine calcifying organisms, these deposits display cross-bedded strata, thinely layered, several metres in thickness. Earlier interpretations suggested that these limestones are ancient beaches at present uplifted. Investigations focusing on geomorphology, lithostratigraphy (identification of internal structures, estimate of size and dip of sedimentary bodies) and sedimentology (grain-size, identification of earlier cement types) reveal that the relevant sediments are medium to very fine-grained, well-sorted sands, steeply dipping landward (up to 30°) and sub-aerially cemented. These lead to regard them as wind-deposited bodies (so-called coastal dune-rocks or eolianites) resulting from prevailing east-south-east, trade-winds, supplied from exposed, marine sedimentary sources, during one or several, mid to late Pleistocene sea-level lowerings.

Objectives The esophageal mucosal integrity is impaired in eosinophilic esophagitis (EoE) and it has been suggested that the duodenal permeability is increased. The absence of food allergens may restore the integrity. The aims of this study were to assess duodenal permeability in EoE and to evaluate the effect of an elemental diet on the esophageal and duodenal integrity. Methods In this prospective study 17 adult EoE patients and 8 healthy controls (HC) were included. Esophageal biopsy specimens were sampled before and after 4 weeks of elemental diet to measure eosinophil counts and gene expression of tight junction and barrier integrity proteins. Esophageal and duodenal impedance were measured by electrical tissue impedance spectroscopy and Ussing chambers were used to measure transepithelial resistance (TER) and transepithelial molecule flux. Small intestinal permeability was measured using a test, measuring lactulose/mannitol (L/M) ratios. Results In EoE patients, the esophageal but not the duodenal integrity was impaired, compared with HC. We observed no significant difference between L/M ratios of HC and EoE patients. After diet, eosinophil counts decreased significantly, which was paralleled by normalization of esophageal impedance and transepithelial molecule flux. The esophageal TER improved significantly, but did not reach values seen in HC. Esophageal expression of genes encoding for barrier integrity proteins filaggrin and desmoglein-1 was impaired at baseline and restored after diet. Conclusions An elemental diet restores esophageal integrity, suggesting that it is at least partly secondary to allergen exposure. Duodenal integrity seems not to be affected in EoE, and possibly plays a minor role in its pathophysiology.