1,963 research outputs found
Macromolecular recognition in the Protein Data Bank
X-ray structures in the PDB illustrate both the specific recognition of two polypeptide chains in proteinâprotein complexes and dimeric proteins and their nonspecific interaction at crystal contacts
Suivi de l'abondance en Trichodesmium spp. (cyanobactéries filamenteuses) et des paramÚtres du milieu lagonaire en baie de Ouinné, Nouvelle-Calédonie : 2 janvier - 3 février 2007
A dual sensor device to estimate fluid flow velocity at diffuse hydrothermal vents
Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part I: Oceanographic Research Papers 56 (2009): 2065-2074, doi:10.1016/j.dsr.2009.06.008.Numerous attempts have been made over the last thirty years to estimate fluid flow
rates at hydrothermal vents, either at the exit of black smoker chimneys or within
diffuse flow areas. In this study, we combine two methods to accurately estimate fluid
flow velocities at diffuse flow areas. While the first method uses a hot film
anemometer that performs high frequency measurements, the second allows a
relatively rapid assessment of fluid flow velocity through video imagery and provides
in situ data to calibrate the sensor. Measurements of flow velocities on hydrothermal
diffuse flow areas were obtained on the Mid-Atlantic Ridge (MAR). They range from
1.1 to 4.9 mm/sec., at the substratum level, in low temperature (4.5 to 16.4°C) diffuse
flow areas from the Tour Eiffel sulfide edifice. A strong correlation was observed
between fluid flow velocities and temperature, supporting the possible use of
temperature as a proxy to estimate flow rates in diffuse flow areas where such a
simple linear flow/temperature relation is shown to dominate.The first part of this research was sponsored by a NOAA/NURP grant award #NA96RU0221 and NSF grant OCE-9901563 to MKT and JS. JS was also supported by a FCAR (Quebec) post-doctoral fellowship. The last part of the project was supported through the ANR DEEP OASES
(ANR06 BDV005)
Coupling the actuator line method to the high order meteorological les model Meso-NH to study wind farm wakes impacts on local meteorology
Offshore wind energy is now reaching the technological maturity, its capacity is increasing all over the world and this trend is projected to continue for several more years. Given this expectation, a better understanding of the relationship between the presence of wind farms and the atmospheric boundary layer is needed. Turbulent wakes produced by wind turbines can significantly impact the flow dynamics within wind farms and downstream of them. Operating offshore parks have already shown losses on energy production and effects on the local climate. In order to analyse the interactions occurring during these impacts, a new tool has been developed. This numerical tool is a coupling between the Actuator Line Method (ALM) and the open-source, non-hydrostatic mesoscale atmospheric model Meso-NH, based on the Large Eddy Simulation (LES) framework. The coupled Meso-NH + ALM system is first validated by using the experimental data obtained during the New MEXICO experiments. In particular, simulated and experimental loadings along the blades are compared. Then, a simulation of an idealized Horns Rev wind farm is performed using met mast measurements and reanalysis data for the âHorns Rev 1 photo caseâ as initial conditions. This new coupled system allows the exploration of the impact of wind farms on the lower levels of the atmosphere.Fil: Joulin, P. A.. French Institute of Petroleum Ănergies nouvelles; Francia. Centre National de Recherches MĂ©tĂ©orologiques; FranciaFil: Mayol, MarĂa Laura. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Centro de SimulaciĂłn Computacional para Aplicaciones TecnolĂłgicas; ArgentinaFil: Blondel, F.. French Institute of Petroleum Ănergies nouvelles; FranciaFil: Masson, Viviana Patricia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Centre National de Recherches MĂ©tĂ©orologiques; FranciaFil: Rodier, Q.. Centre National de Recherches MĂ©tĂ©orologiques; FranciaFil: Lac, C.. Centre National de Recherches MĂ©tĂ©orologiques; Franci
Surface plasmons of metallic surfaces perforated by nanoholes
Recent works dealt with the optical transmission on arrays of subwavelength
holes perforated in a thick metallic film. We have performed simulations which
quantitatively agree with experimental results and which unambiguously evidence
that the extraordinary transmission is due to the excitation of a
surface-plasmon-polariton (SPP) mode on the metallic film interfaces. We
identify this SPP mode and show that its near-field possesses a hybrid
character, gathering collective and localised effects which are both essential
for the transmission.Comment: 16 pages, 4 figure
Swelling of Transported Smoke from Savanna Fires over the Southeast Atlantic Ocean
We use the recently released Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) Version 4.1 (V4) lidar data to study the smoke plumes transported from Southern African biomass burning areas. Significant improvements in the CALIPSO V4 Level 1 calibration and V4 Level 2 algorithms lead to a better representation of their optical properties, with the aerosol subtype improvements being particularly relevant to smoke over this area. For the first time, we show evidence of smoke particles increasing in size, evidenced in their particulate color ratios, as they are transported over the South Atlantic Ocean from the source regions over Southern Africa. We hypothesize that this is due to hygroscopic swelling of the smoke particles and is reflected in the higher relative humidity in the middle troposphere for profiles with smoke. This finding may have implications for radiative forcing estimates over this area and is also relevant to the ORACLES field mission
Hair Manganese and Hyperactive Behaviors: Pilot Study of School-Age Children Exposed through Tap Water
BACKGROUND: Neurotoxic effects are known to occur with inhalation of manganese particulates, but very few data are available on exposure to Mn in water. We undertook a pilot study in a community in QuĂ©bec (Canada) where naturally occurring high Mn levels were present in the public water system. Our objective was to test the hypothesis that greater exposure to Mn via drinking water would be reflected in higher Mn content in hair which, in turn, would be associated with increased level of hyperactive behaviors. METHODS: Forty-six children participated in the study, 24 boys and 22 girls, 6â15 years of age (median, 11 years). Their homes received water from one of two wells (W) with different Mn concentrations: W1: mean 610 ÎŒg/L; W2: mean 160 ÎŒg/L. The Revised Connersâ Rating Scale for parents (CPRS-R) and for teachers (CTRS-R) were administered, providing T-scores on the following subscales: Oppositional, Hyperactivity, Cognitive Problems/Inattention, and ADHD Index. RESULTS: Children whose houses were supplied by W1 had higher hair Mn (MnH) than those supplied by W2 (mean 6.2 ± 4.7 ÎŒg/g vs. 3.3 ± 3.0 ÎŒg/g, p = 0.025). MnH was significantly associated with T-scores on the CTRS-R Oppositional (p = 0.020) and Hyperactivity (p = 0.002) subscales, after adjustment for age, sex, and income. All children with Oppositional and Hyperactivity T-scores â„ 65 had MnH > 3.0 ÎŒg/g. CONCLUSIONS: The findings of this pilot study are sufficiently compelling to warrant more extensive investigations into the risks of Mn exposure in drinking water
- âŠ