Kleptoplastic foraminifera: a trophic strategy of life 

2021 ◽  
Author(s):  
Julia Courtial ◽  
Edouard Metzger ◽  
Jérémy Lothier ◽  
Constance Choquel ◽  
Anis M. Limami ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Atlantic Coast ◽  
Deep Ocean ◽  
Environmental Indicators ◽  
Sediment Geochemistry ◽  
Gas Chromatography Mass Spectrometry ◽  
Life Strategy ◽  
Foraminiferal Species ◽  
Trophic Strategy ◽  
Set Up

<p>Foraminifera are single-celled organisms, and part of protists. They are present in all types of environments, though most foraminifera are marine benthic and are found from the deep ocean to the intertidal zone. Thus, foraminifera are subjected to various environmental stresses, (natural or anthropogenic). Because of their rapid response to stresses and their strong resistance, foraminifera are studied as paleo-environmental indicators. However, little is currently known about their biology, and specifically their metabolism and physiology. Some foraminifera species are notably known to retain, in their cytoplasm, chloroplasts from diatom preys. This phenomenon is called kleptoplasty. It has been shown that kleptoplasts remain intact and photosynthetically functional from a few days to several weeks, depending of the foraminiferal species and abiotic factors as light. In order to better understand this life strategy and the advantages provided to foraminifera by kleptoplasty in a coastal mudflat environment, we study metabolism of kleptoplastic and non-kleptoplastic species.</p><p>The “Mudsurv” (Mudflat survey, OSUNA) project initiated in 2016 a monitoring of the foraminiferal fauna and sediment geochemistry of Bourgneuf Bay (French Atlantic Coast). The main foraminiferal species observed were: <em>Ammonia sp. </em>T6, <em>Elphidium oceanense</em> and a kleptoplastic specie, <em>Haynesina germanica</em>. We therefore set up a monthly monitoring of respiration and photosynthesis of those kleptoplast and non-kleptoplast foraminifera species. The oxygen production or consumption is measured by microelectrodes in light and darkness. Preliminary results suggest a seasonality of photosynthesis in kleptoplast foraminifera. A second approach, using gas chromatography-mass spectrometry (GC-MS)-based experiments, provided us with the first’s foraminifera metabolomes highlighting kleptoplast species metabolic specificities.</p>

scholarly journals Addressing the COVID-19 transmission in inner Brazil by a mathematical model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
G. B. Almeida ◽  
T. N. Vilches ◽  
C. P. Ferreira ◽  
C. M. C. B. Fortaleza
Keyword(s):  
Mathematical Model ◽  
Disease Transmission ◽  
Abiotic Factors ◽  
Severe Pneumonia ◽  
Mitigation Strategies ◽  
Social Distancing ◽  
Control Disease ◽  
Set Up ◽  
Novel Coronavirus ◽  
Public Health Strategies

AbstractIn 2020, the world experienced its very first pandemic of the globalized era. A novel coronavirus, SARS-CoV-2, is the causative agent of severe pneumonia and has rapidly spread through many nations, crashing health systems and leading a large number of people to death. In Brazil, the emergence of local epidemics in major metropolitan areas has always been a concern. In a vast and heterogeneous country, with regional disparities and climate diversity, several factors can modulate the dynamics of COVID-19. What should be the scenario for inner Brazil, and what can we do to control infection transmission in each of these locations? Here, a mathematical model is proposed to simulate disease transmission among individuals in several scenarios, differing by abiotic factors, social-economic factors, and effectiveness of mitigation strategies. The disease control relies on keeping all individuals’ social distancing and detecting, followed by isolating, infected ones. The model reinforces social distancing as the most efficient method to control disease transmission. Moreover, it also shows that improving the detection and isolation of infected individuals can loosen this mitigation strategy. Finally, the effectiveness of control may be different across the country, and understanding it can help set up public health strategies.

The Tahaddart estuary, NW of Morocco: evidence of marine submersion events during the last 3500 years 

2021 ◽  
Author(s):  
Otmane Khalfaoui ◽  
laurent Dezileau ◽  
Jean-Philippe Degeai ◽  
Maria Snoussi
Keyword(s):  
Late Holocene ◽  
Atlantic Coast ◽  
High Energy ◽  
Mitigation Strategies ◽  
Spatial And Temporal Variability ◽  
Progressive Change ◽  
Marine Facies ◽  
Set Up ◽  
Long Term Studies

<p>The Atlantic coast of Morocco has been confronted with several marine submersion events. Historically, some of them have resulted in significant economic and human damage, including the 1755 AD event (known as the tsunami of Lisbon). This indicates the need to implement adaptation and mitigation strategies, based on long-term studies of these extreme events to deduce their spatial and temporal variability. Using two cores (TAH17-1 and TAH17-3) collected from the Tahaddart estuary (NW of Morocco), this work aims to identify deposits, set up by these high energy events during the mid to late Holocene period. The sedimentological, geochemical and geochronological analyses carried out on these geological archives show two fining-upward sequences, indicating a progressive change from a purely sandy marine facies, between 6500 and 3500 BP, to another finer and more terrigenous one. The fine sedimentation, which has dominated in the estuary during the last 3500 years, has facilitated the recording of several marine submersion events in the form of isolated sandy layers. Chronological data have made it possible to date four deposits. Two (1-E1 and 3-E1) were put in place about 250 years ago, which corresponds, according to historical records, to the 1755 AD Lisbon tsunami. Two other deposits (1-E13 and 1-E14) are dated around 3200 BP and represent unknown submersion events on the Moroccan Atlantic coast.</p>

Florida Inlets and Intertidal Biofouling Communities

2017 ◽  
Vol 51 (2) ◽  
pp. 7-21 ◽  
Author(s):  
Kevin B. Johnson ◽  
Jayden L. Roberts
Keyword(s):  
Atlantic Coast ◽  
Environmental Indicators ◽  
Rocky Intertidal ◽  
Drainage Basins ◽  
Bugula Neritina ◽  
Bare Rock ◽  
The North ◽  
Latitudinal Patterns ◽  
Invasive Bryozoan ◽  
Community Component

AbstractThis study reports on the identity and coverage of rocky intertidal species in the major inlets of Florida’s Atlantic coast. From north to south, these inlets are Fort George, St. Augustine, Ponce De Leon, Port Canaveral, Sebastian, Fort Pierce, Jupiter, Lake Worth, Boca Raton, Port Everglades, Baker’s Haulover, and Port of Miami. Dominant coverage in the southerly inlets included star corals (Siderastrea radians, 62% Port of Miami), ribbed barnacles (Tetraclita stalactifera, 18% Port Everglades), and zoanthid corals (Palythoa sp., 40% Baker’s Haulover). In the north, the community shifted and species absent in the south became common (e.g., eastern oysters Crassostrea virginica, 9% Fort George, 15% St. Augustine; the macroalga Enteromorpha lactuca, 10% Fort George, 17% Sebastian Inlet). The invasive bryozoan Bugula neritina was always present north of the Port of Miami and was a major community component north of Port Everglades (e.g., 27% Fort Pierce Inlet and 22% Ponce de Leon Inlet). Correlations between intertidal populations and environmental indicators included the oyster C. virginica with various sea surface temperature (SST) parameters (e.g., inverse correlations with max SST, R2 = 0.81, p = .038). Likewise, the coralline alga Pneophyllum fragile was correlated with various SST parameters (e.g., min SST, R2 = 0.51, p = .020). Bare rock and B. neritina both showed inverse correlations with the human population of inlet drainage basins (R2 = 0.28, p = .040 and R2 = 0.33, p = .026, respectively), the latter relationship an unexpected pattern for a notorious invader. These data show latitudinal patterns and provide baselines for future comparisons in the wake of projected climate change.

Comparative Study on Rate of Biodegradation of Diluted Bitumen and Conventional Oil in Fresh Water

2017 ◽  
Vol 2017 (1) ◽  
pp. 2256-2267
Author(s):  
Ruta Suresh Deshpande ◽  
Devi Sundaravadivelu ◽  
Pablo Campo ◽  
Jorge W. SantoDomingo ◽  
Robyn N. Conmy
Keyword(s):  
Mixed Culture ◽  
16S Rrna Gene Sequencing ◽  
Gas Chromatography Mass Spectrometry ◽  
Rrna Gene ◽  
Sequencing Analysis ◽  
Dispersed Oil ◽  
Degradation Rates ◽  
Degrading Bacteria ◽  
Rrna Gene Sequencing ◽  
Set Up

Abstract 2017-271 In recent years, diluted bitumen (or dilbit) has become an important source of hydrocarbon-based fuel. While information on the degradation of crude oils has been well researched, dilbit degradation has been studied at a much lesser extent. The objective of this study was to compare biodegradation of dilbit with a conventional crude oil (CCO) under various conditions. Two different microcosm experiments were set up, one containing a mixed culture acclimated to dilbit (Kalamazoo River Enrichment, KRC) and the other having a mixed culture enriched on soil contaminated with hydrocarbons (Anderson Ferry Enrichment, AFC). The microcosms were run for 60 d at 25 °C and for 72 days at 5 °C in flasks containing sterile Bushnell Hass broth and naturally dispersed oil. Each flask was inoculated with the KRC and AFC mixed cultures, and rotated on an orbital shaker (200 rpm) at the above stated temperatures. On each sampling day, triplicates were sacrificed to determine the residual hydrocarbon concentration. Additionally, some samples were used to determine the bacterial composition using 16S rRNA gene sequencing analysis. Hydrocarbon analysis (alkanes and PAHs) was performed by gas chromatography/mass spectrometry (GC/MS/MS). Higher degradation rates were achieved at 25 °C as compared to 5 °C. All the enrichments metabolized CCO as well dilbit, but the nature and extent of the degradation was distinct. KRC meso culture was the most effective among all, as it completely removed alkanes and most of the PAHs. AFC enrichment performed differently at the two temperatures; an acclimation period (8 d) was observed at 5 °C while there was no lag at 25 °C. KRC cryo culture as well as AFC culture at both temperatures degraded alkanes completely while they were not able to metabolize heavier fractions of the oil (C2–4 homologues of 3- and 4-ring compounds). All cultures showed the presence of diverse oil degrading bacteria and the differences in their compositions affected the biodegradation. Although dilbit was biodegraded, for all the treatments except AFC at 5 °C, the rate of degradation and the extent of degradation was greater for CCO owing to the higher concentrations of lighter hydrocarbons.

scholarly journals An airborne perfluorocarbon tracer system and its first application for a Lagrangian experiment

2014 ◽  
Vol 7 (7) ◽  
pp. 6791-6822
Author(s):  
Y. Ren ◽  
R. Baumann ◽  
H. Schlager
Keyword(s):  
Stratospheric Ozone ◽  
Lagrangian Model ◽  
Research Vessel ◽  
Gas Chromatography Mass Spectrometry ◽  
Sampling System ◽  
Tracer System ◽  
Research Aircraft ◽  
Set Up ◽  
German Aerospace ◽  
First Time

Abstract. A perfluorocarbon tracer system (PERTRAS), specifically designed for Lagrangian aircraft experiments, has been developed by the Deutsches Zentrum für Luft- und Raumfahrt (German Aerospace Center, DLR). It consists of three main parts: a tracer release unit (RU), an adsorption tube sampler (ATS) and a tracer analytical system. The RU was designed for airborne tracer release experiments; meanwhile, it can be used on various platforms for different experimental purpose (here research vessel). PERTRAS was for the first time applied in the field campaign Stratospheric ozone: halogen Impacts in a Varying Atmosphere (SHIVA) in November 2011. An amount of 8.8 kg perfluoromethylcyclopentane (PMCP) was released aboard the research vessel Sonne (RV Sonne) near the operational site of this campaign, Miri, Malaysia, on 21 November. The tracer samples collected using the ATS on board the DLR research aircraft Falcon were analyzed in the laboratory using a thermal desorber/gas chromatography/mass spectrometry (TD/GC/MS) system. Guided by forecasts calculated with the Lagrangian model, Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT), 64 tracer samples were collected onboard the Falcon approximately 5 and 25 h after the release, respectively, mostly with a time resolution of 1 min. Enhanced PMCP concentrations relative to ambient PMCP background values (mean: 6.62 fmol mol−1) were detected during three intersects of the fresh tracer plume (age 5 h), with a maximum value of 301.33 fmol mol−1. This indicates that the fresh tracer plume was successfully intercepted at the forecasted position. During the second flight, 25 h after the release, the center of tracer plume was not detected by the sampling system due to a faster advection of the plume than forecasted. The newly developed PERTRAS system has been successfully deployed for the first time. The instrumental set-up and comparisons between the measurements and HYSPLIT simulations are presented in this study.

scholarly journals Use of ovitraps for the seasonal and spatial monitoring of Aedes spp. in an area endemic for arboviruses in Northeast Brazil

2020 ◽  
Vol 14 (04) ◽  
pp. 387-393
Author(s):  
João Victor Oliveira Noleto ◽  
Hevilem Letícia Moura do Nascimento Moraes ◽  
Tamires De Moura Lima ◽  
João Gustavo Mendes Rodrigues ◽  
Diogo Tavares Cardoso ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Spatial Analysis ◽  
High Risk ◽  
Mathematical Models ◽  
Low Cost ◽  
Abiotic Factors ◽  
Northeast Brazil ◽  
Egg Distribution ◽  
Egg Density ◽  
Set Up

Introduction: Due to recent outbreaks of Dengue and Chikungunya and an absence of effective monitoring of the mosquito Aedes spp. in the municipality of São Raimundo das Mangabeiras, State of Maranhão, we aimed to demonstrate the potential of ovitraps used together with mathematical models and geotechnology to improve control of this mosquito. Methodology: From January to December of 2017, ovitraps were set up in five different neighborhoods (Centro, Vila Cardoso, Nazaré, São José e São Francisco). Positivity indices were calculated for each ovitraps, besides the egg density and average number of eggs. Some of the eggs were used for species identification. Mathematical models of correlation and logistic regression were used to evaluate the influence of abiotic factors on egg distribution during each month. Spatial analysis was carried out using georeferencing. Results: A total of 4,453 eggs were counted, with A. aegypti and A. albopictus present in each month and neighborhood. The mathematical models show that rainfall can result in a significant increase in the number of eggs. Entomological calculation indicates that there is a high risk of dissemination of arboviruses in the area. Spatially, it was possible to indicate sites with the largest number of collected eggs, which may facilitate future interventions. Conclusions: As such, ovitraps have proven to be an effective and low cost method for the monitoring of Aedes spp., and that its use may help in arboviruses prevention campaigns.

scholarly journals Wine yeast phenomics: a standardized fermentation method for assessing quantitative traits ofSaccharomyces cerevisiaestrains in enological conditions

2017 ◽  
Author(s):  
Emilien Peltier ◽  
Margaux Bernard ◽  
Marine Trujillo ◽  
Duyên Prodhomme ◽  
Jean-Christophe Barbe ◽  
...  
Keyword(s):  
Kinetic Parameters ◽  
Quantitative Traits ◽  
Alcoholic Fermentation ◽  
Solid Phase ◽  
Wine Yeast ◽  
Gas Chromatography Mass Spectrometry ◽  
Small Scale ◽  
Set Up ◽  
Volatiles Compounds ◽  
Grape Juices

AbstractThis work describes the set up of a small scale fermentation methodology for measuring quantitative traits of hundreds of samples in an enological context. By using standardized screw cap vessels, the alcoholic fermentation kinetics ofSaccharomyces cerevisiaestrains were measured by following the weight loss over time. Preliminary results showed that the kinetic parameters measured are in agreement with those observed in larger scale vats. The small volume used did not impair any analysis of the strain performance. Indeed, this fermentation system was coupled with robotized enzymatic assays and 8 end-point metabolites of enological interest were measured accurately. Moreover, the vessel used offers the possibility to assay 32 volatiles compounds using a headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry approach. Data presented demonstrates that the shaking conditions significantly impacted the mean and the variance of kinetic parameters, primary metabolites, and the production of volatile compounds. This effect was likely due to an enhanced transfer of dissolved oxygen during the first hours of the alcoholic fermentation. To test the efficiency of this experimental design, the phenotypic response of 35 wine industrial starters was measured in five grape juices from the Bordeaux area. A multivariate analysis illustrated that strains were better discriminated by some grape must, than others. The technological performances as well as the phenotypic robustness of these strains was measured and discussed. The optimized methodology developed allows investigating multiple fermentation traits for numerous yeast strains and conditions and greatly contributes in achieving quantitative genetics studies as well as yeast selection programs.

Fully automated flow-injection system for quantifying 1,5-anhydro-D-glucitol in serum

1994 ◽  
Vol 40 (11) ◽  
pp. 2006-2012 ◽  
Author(s):  
T Tanabe ◽  
Y Umegae ◽  
Y Koyashiki ◽  
Y Kato ◽  
K Fukahori ◽  
...  
Keyword(s):  
Flow Injection ◽  
Colorimetric Detection ◽  
Enzymatic Reaction ◽  
Injection System ◽  
Gas Chromatography Mass Spectrometry ◽  
Present System ◽  
Serum Samples ◽  
Patients With Diabetes ◽  
Flow Injection System ◽  
Set Up

Abstract We have developed a flow-injection system with colorimetric detection to measure 1,5-anhydro-D-glucitol in serum. Serum samples are directly and serially injected into a clean-up column every 3.5 min to remove interferences before the enzymatic reaction. 1,5-Anhydro-D-glucitol, after being passed through the column, is oxidized by immobilized pyranose oxidase (EC 1.1.3.10), and the hydrogen peroxide produced reacts with the chromogen substrate in the presence of immobilized horseradish peroxidase (EC 1.11.1.7) to form Bindshedler's Green. The detection limit was 1.2 mumol/L (1.2 pmol). The correlation between results obtained with the present system (y) and gas chromatography-mass spectrometry (GC-MS) (x) in samples containing < 30 mumol/L 1,5-anhydro-D-glucitol, including many samples from patients with diabetes mellitus, was y = 0.975x-0.111 mumol/L (r = 0.997), which was superior to that obtained between the enzymatic and GC-MS methods. Our system needs only to be set up; it runs without any manual pretreatment, assays 17 samples/h, and shows imprecision (CV) of < 2%.

Wastewater Reuse in France: Water Quality Standards and Wastewater Treatment Technologies

1999 ◽  
Vol 40 (4-5) ◽  
pp. 37-42 ◽  
Author(s):  
J. A. Faby ◽  
F. Brissaud ◽  
J. Bontoux
Keyword(s):  
Water Quality ◽  
Water Resources ◽  
Atlantic Coast ◽  
Wastewater Reuse ◽  
Ultra Violet ◽  
Treated Wastewater ◽  
Ministry Of Health ◽  
Shellfish Farming ◽  
Bathing Waters ◽  
Set Up

Wastewater reuse is not widely applied in France, because water resources match most of the needs. Only 6 projects were in operation in 1989. But more than 15 new projects were found to have been set up 7 years later. In the meantime, the Ministry of Health issued a provisional regulation on the reuse of wastewater for irrigation purposes and the Ministry of Environment a Water Law and application decrees acknowledging wastewater reuse as a means of disposal for treated wastewater, which is recommended to be implemented along the coastline. Actually, most of the projects are located in Atlantic islands and on the Atlantic coast. They were developed not only to face the limitation of water resources but also as a means of protecting bathing waters and shellfish farming areas. Most hinterland projects were driven by the rehabilitation of rivers threatened by eutrophication. The inforcement of the recommendations of the Ministry of Health resulted in a slowing down of the development of wastewater reuse and the implementation of wastewater treatments–long residence time lagooning or chlorination ad ultra violet radiations–providing water quality higher than required by the standards.

Test Set-Up for Irregular Vertical Hydraulic Transport in Deep Ocean Mining

2011 ◽  
Author(s):  
Arno M. Talmon ◽  
Cees van Rhee
Keyword(s):  
Fine Particles ◽  
Deep Ocean ◽  
Ocean Surface ◽  
Processing Plant ◽  
Coarse Particles ◽  
Hydraulic Transport ◽  
Test Set ◽  
Sea Floor ◽  
High Concentrations ◽  
Set Up

The mining of scarce minerals from the sea-floor at the depths of several kilometers and bringing them to a processing plant at the ocean surface requires new techniques. Seafloor Massive Sulphide (SMS) deposits are known to have an extremely rich mineral content, and are considered technically-economically-environmentally feasible to explore. Vertical hydraulic transport is the link between the sea-floor mining and the maritime vessel where the first processing stage will take place. Clogging of any part of the vertical transport system is an absolute disaster. Fine particles are conveyed faster than coarse particles. High concentrations of fines cannot bypass high concentrations of coarse particles, hence these particle fractions accumulate, potentially blocking the pipe. Fundamental research into yet unexplored physics is necessary. Besides numerical flow simulations, it is necessary to conducted experiments on the transport over large vertical distances. Such tests aim to investigate the dynamic development of density waves consisting of different particle diameters and clogging phenomenon thereof. Different particle size fractions have to be followed in real time as they overtake each other, and change their shape, merge and segregate. It is however impossible to back-scale the prototype riser to a one-pass laboratory test set-up, but the process can be simulated by repeated flow through an asymmetric vertical pipe loop, where slurry flow in the upward leg represent vertical hoist conditions and the slurry is returned quickly via the downward leg. The particle accumulation process is allowed to take place in the upward leg whereas in the downward leg the restoring process is nearly neutralized. The development of accumulations in time (= distance traveled to the ocean surface) can be followed upon multiple passes of the solids batches through the upward leg. The novelty of the described testing method is that the essentials of fundamental processes occurring in long vertical stretches are quantified in a specially designed laboratory setup. Via subsequent implementation of the results in a numerical flow simulation, reliable transport scenarios can be delineated.

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