Etude pilote des apports en contaminants par la Seine : niveaux de contamination, variations saisonnières et flux d'éléments traces a poses en 1990 et 1991

Le présent rapport constitue une première présentation des résultats de l'Etude pilote des apports en contaminants par la Seine. Il est consacré aux métaux et à l'arsenic et traite de leurs niveaux de concentration, de leurs variations saisonnières et des flux à l'estuaire. Il comporte des fiches-annexes qui contiennent les méthodes de prélèvement, de filtration et de dosage ainsi que des résumés des résultats. A partir des conclusions, des recommandations sont faites quant aux méthodes à privilégier pour tirer les meilleurs enseignements du suivi des contaminants métalliques et de l'arsenic à la limite amont de l'estuaire de la Seine. Les données contenues dans ce rapport ont été produites par la Cellule de lutte contre la pollution (Service de navigation de la Seine), le laboratoire Chimie des contaminants et modélisation (IFREMER) et le Laboratoire municipal et régional de Rouen.

Investigation into the meteorological aspects of the variations in the level of Lake Victoria

The level of Lake Victoria has, since 1961, reached a height which caused serious flood damage. Already the financial implications are considerable for Kenya, Tanzania and Uganda. If further rises can be anticipated, expenditure on flood control measures to the tune of several million pounds sterling must be envisaged. If such rises should lead to uncontrolled discharge at the Owen Falls Dam site because of overshooting, downstream districts of Uganda and the Sudan may be seriously flooded. All this merits a thorough study, and any indication of the future behaviour of lake levels, even when associated with a low probability, must be taken into account. In these circumstances the Water Development Department of Kenya approached the East African Meteorological Department in November, 1964, on behalf of all parties concerned with the request to study the meteorological background of the Iake level variation, with a view to forecasting future behaviour.

Récentes variations de temperature et de salinité à Nhatrang (avec une Annexe des données des autres points fixes établis dans le passé)

The authors expose results of recent routine observations and those of oceanographic stations undertaken in 1957, at Nhatrang. They introduce also in the Note, results of others fixed observations-stations for comparisons.

Supplement a la Note (partie B): Récentes variations de température et de salinité de Nha-trang

The present reexamination of oceanographic stations data done in 1957, by graphics, aims to complete necessarily the part B of the last note of the author

Savani: A variable resolution whole-mantle model of anisotropic shear velocity variations based on multiple data sets

International audience

The Southeast Indian Ridge between 88°E and 118°E: Variations in crustal accretion at constant spreading rate

The temperature of the mantle and the rate of melt production are parameters which play important roles in controlling the style of crustal accretion along mid-ocean ridges. To investigate the variability in crustal accretion that develops in response to variations in mantle temperature, we have conducted a geophysical investigation of the Southeast Indian Ridge (SEIR) between the Amsterdam hotspot and the Australian-Antarctic Discordance (88 degrees E-118 degrees E). The spreading center deepens by 2100 m from west to east within the study area. Despite a uniform, intermediate spreading rate (69-75 mm yr-l), the SEIR exhibits the range in axial morphology displayed by the East Pacific Rise and the Mid-Atlantic Ridge (MAR) and usually associated with variations in spreading rate. The spreading center is characterized by an axial high west of 102 degrees 45'E, whereas an axial valley is prevalent east of this longitude. Both the deepening of the ridge axis and the general evolution of axial morphology from an axial high to a rift valley are not uniform. A region of intermediate morphology separates axial highs and MAR-like rift valleys. Local transitions in axial morphology occur in three areas along the ridge axis. The increase in axial depth toward the Australian-Antarctic Discordance may be explained by the thinning of the oceanic crust by similar to 4 km and the change in axial topography. The long-wavelength changes observed along the SEIR can be attributed to a gradient in mantle temperature between regions influenced by the Amsterdam and Kerguelen hot spots and the Australian-Antarctic Discordance. However, local processes, perhaps associated with an heterogeneous mantle or along-axis asthenospheric flow, may give rise to local transitions in axial topography and depth anomalies.

Investigation and prediction of sea level variations in the northern coasts of Persian Gulf using artificial neural network

Sea- level variations have a significant impact on coastal areas. Prediction of sea level variations expected from the pre most critical information needs associated with the sea environment. For this, various methods exist. In this study, on the northern coast of the Persian Gulf have been studied relation to the effectiveness of parameters such as pressure, temperature and wind speed on sea leve and associated with global parameters such as the North Atlantic Oscillation index and NAO index and present statistic models for prediction of sea level. In the next step by using artificial neural network predict sea level for first in this region. Then compared results of the models. Prediction using statistical models estimated in terms correlation coefficient R = 0.84 and root mean square error (RMS) 21.9 cm for the Bushehr station, and R = 0.85 and root mean square error (RMS) 48.4 cm for Rajai station, While neural network used to have 4 layers and each middle layer six neurons is best for prediction and produces the results reliably in terms of correlation coefficient with R = 0.90126 and the root mean square error (RMS) 13.7 cm for the Bushehr station, and R = 0.93916 and the root mean square error (RMS) 22.6 cm for Rajai station. Therefore, the proposed methodology could be successfully used in the study area.

Regulatory T and B cells in asthmatic women: variations from pregnancy to postpartum Treg and Breg: pregnancy to postpartum

BACKGROUND: Allergic asthma and rhinitis are common in pregnancy. The immune mechanisms underlying the effects of pregnancy in asthma and vice-versa are not completely understood. OBJECTIVES: This work aimed to study the evolution of regulatory T and B cells in asthmatic pregnant women, from late pregnancy till postpartum. METHODS: Four groups of women were enrolled for this study: third trimester pregnant women, asthmatic (n=24) and healthy (n=43), and non-pregnant women, asthmatic (n=33) and healthy (n=35). Pregnant women were also evaluated postpartum (>6 weeks after delivery). Blood samples were taken from each woman and flow cytometry was used to characterize circulating regulatory T and B cells. Foxp3 expression was assessed within CD4DimCD25Hi regulatory T cells. RESULTS: In asthmatic and healthy pregnant women, regulatory T cells did not oscillate significantly from pregnancy to postpartum, but CD24HiCD38Hi regulatory B cells, decreased in pregnancy, rose significantly postpartum. Foxp3 expression in regulatory T cells was also impaired during pregnancy in asthmatic and healthy pregnant women, recovering postpartum. Nevertheless, asthmatic pregnant women presented higher Foxp3 expression than healthy pregnant women (p=0.007), probably due to the use of control medication. CONCLUSIONS: Women with controlled asthma present variations in regulatory cell subsets during pregnancy and postpartum. The similar pattern observed for Foxp3 expression and CD24HiCD38Hi regulatory B cells during this period corroborates the interaction established between regulatory T and B cells in immune responses. Considering the immunomodulatory potential of these immune mediators, more studies are needed to evaluate their relation with asthma and rhinitis complications in pregnancy.

Analysis of cyclic variations during mode switching between spark ignition and controlled auto-ignition combustion operations

© IMechE 2014. Controlled auto-ignition, also known as homogeneous charge compression ignition, has been the subject of extensive research because of their ability to provide simultaneous reductions in fuel consumption and NOx emissions from a gasoline engine. However, due to its limited operation range, switching between controlled auto-ignition and spark ignition combustion is needed to cover the complete operating range of a gasoline engine for passenger car applications. Previous research has shown that the spark ignition -controlled auto-ignition hybrid combustion (SCHC) has the potential to control the ignition timing and heat release process during the mode transition operations. However, it was found that the SCHC is often characterized with large cycle-to-cycle variations. The cyclic variations in the in-cylinder pressure are particularly noticeable in terms of both their peak values and timings while the coefficient of variation in the indicated mean effective pressure is much less. In this work, the cyclic variations in SCHC operations were analyzed by means of in-cylinder pressure and heat release analysis in a single-cylinder gasoline engine equipped with Variable Valve Actuation (VVA) systems. First, characteristics of the in-cylinder pressure traces during the spark ignition-controlled auto-ignition hybrid combustion operation are presented and their heat release processes analyzed. In order to clarify the contribution to heat release and cyclic variation in SCHC, a new method is introduced to identify the occurrence of auto-ignition combustion and its subsequent heat release process. Based on the new method developed, the characteristics of cyclic variations in the maximum rate of pressure rise and different stages of heat release process have been analyzed and discussed.

Seasonal variations in chemical composition and stable isotopes of farmed and wild Brazilian freshwater fish

This study examined variations in the Fulton condition factor, chemical composition, and stable isotopes of carbon and nitrogen in the Brazilian freshwater fish cachara (Pseudoplatystoma fasciatum), comparing farmed and wild fish in different seasons. Values for energy, protein, moisture, and Fulton's condition factor were higher for farmed than for wild fish in the rainy season, indicating better nutritional quality; however, these differences were not observed in the dry season. Likewise, we found significant enhancement of delta(15)N in farmed fish in the rainy season but not in the dry season, whereas enhancement of delta(13)C was observed in both seasons. The combined measurement of delta(13)C and delta(15)N provided traceability under all conditions. Our findings show that stable isotope analysis of C and N can be used to trace cachara origin, and that seasonal variations need to be considered when applying chemical and isotopic authentication of fish and fish products. (C) 2010 Elsevier Ltd. All rights reserved.