87 research outputs found
Telomere length and obesity
No full textAim: To assess the telomere length in apparently healthy obese and normal-weight subjects. Methods: Seventy-six Caucasian subjects were chosen including 53 children (age 8.2 ± 3.5 years) and 23 adults (age 40.5 ± 8.4 years). Among these, 22 (12 children and 10 adults) were obese with a body mass index (BMI, kg/m2) > 2 SD above the norm. Bioelectrical impedance analysis (BIA), measured with a multiple frequency analyzer, was used to estimate body composition. DNA extraction from white blood cells was used to estimate the telomere length by detection of terminal restriction fragments (TRF). Results: No difference was found between the TRF lengths of obese and normal children. Obese adults had shorter TRF lengths than adults who were not obese (mean TRF length difference, -884.5; 95% confidence intervals -1727 to -41.8; t = 2.183; df = 17; p < 0.041). Conclusions: Obese adults have shorter telomeres than their normal-weight counterparts, while this phenomenon is not present in childhood. © 2008 The Author(s)
Pathways and Water Mass Transformation Along and Across the Mohn‐Knipovich Ridge in the Nordic Seas
No full textAtlantic Water takes various pathways through the Nordic Seas, and its transformation to denser waters forms a crucial connection to the lower limb of the Atlantic Meridional Overturning Circulation. Circulation maps often schematize two distinct pathways of Atlantic Water: one following the Norwegian Atlantic Slope Current along the continental slope of Norway and one following the Norwegian Atlantic Front Current along the Mohn and Knipovich Ridges. In this paper, the connectivity between the northward flow along these ridges is investigated. Analyzing trajectories of surface drifters and ARGO floats, we find that only 8% of the floats that travel near the mid-ocean ridges take the frontal pathway to the north. Indeed, by tracing numerical particles in a realistic numerical simulation, part of the water mass traveling along the Mohn Ridge follows the 2,500 m isobath eastward and joins the slope current, instead of flowing north along the Knipovich Ridge. Furthermore, north of 74°N, frequent exchange between the slope current and the front current is observed. Therefore, the slope current and front current are less isolated than often schematized. Additionally, the observational data set reveals substantial cross-ridge exchange; 31% of the floats that travel within 60 km from the mid-ocean ridges cross it. Results from numerical simulations indicate that the cross-ridge exchange leads to cooling and freshening of the Atlantic Water along the front. Deployments of floats near the mid-ocean ridges are needed to investigate the pathway of Atlantic Water and its exchange across the ridge in more detail.Environmental Fluid Mechanic
Measurement of the inelastic proton–proton cross-section at √s=7 TeV with the ATLAS Detector
No full textA first measurement of the inelastic cross-section is presented for proton-proton collisions at a center of mass energy √ =7 TeV using the ATLAS detector at the Large Hadron Collider. In a dataset corresponding to an integrated luminosity of 20 µb<sup>-1</sup>, events are selected by requiring hits on scintillation counters mounted in the forward region of the detector. An inelastic cross-section of 60.3 ± 2.1 mb is measured for ξ>5x10<sup>-6</sup>, where ξ=M<sup>2</sup><sub>X</sub>/s is calculated from the invariant mass, M<sub>X</sub>, of hadrons selected using the largest rapidity gap in the event. For diffractive events this corresponds to requiring at least one of the dissociation masses to be larger than 15.7 GeV
Minimum impact house prototype for sustainable building
No full textThe Minihouse is a prototupe for a sustainable townhouse. On a site of only 29 sqm it offers 154 sqm of urban life. The project 'Minimum Impact House' adresses two important questions: How do we provide living space in the cities without distroying the landscape? How to improve sustainably the ecological, economical and socio-cultural performance of buildings?UrbanismArchitectur
Effect Of Tm Substitution On The Magnetic And Magnetocaloric Properties In The Intermetallic Compounds (tb1-xtmx)co2
No full textThe magnetic and magnetocaloric properties of the intermetallic compounds Tb1-xTmxCo2 (with x ≤ 0, 0.2 and 0.5) have been studied. It is found that partial replacement of Tb by Tm in TbCo 2 leads to a reduction in the ordering temperature, which is attributed to the decrease in the exchange strength due to the lower spin value of Tm3+ as compared with that of Tb3+. The analysis of the zero-field heat capacity data at low temperature shows that the coefficient of electronic heat capacity increases with increase in Tm content and is attributed to the presence of local spin fluctuations. The variation of the magnetocaloric effect (MCE) has been explained on the basis of the magnetic properties. Temperature dependence of the MCE shows that this system may be useful for magnetic refrigeration applications in a sub-room temperature regime. © 2007 IOP Publishing Ltd.40616201625Tishin, A.M., Spichkin, Y.I., (2003) The Magnetocaloric Effect and Its ApplicationsGschneidner, K.A., Pecharsky, V.K., Tsokol, A.O., (2005) Rep. Prog. Phys., 68 (6), p. 1479Pecharsky, V.K., Gschneidner, K.A., (1997) Appl. Phys. Lett., 70 (24), p. 3299Singh Niraj, K., Agarwal, S., Suresh, K.G., Nirmala, R., Nigam, A.K., Malik, S.K., (2005) Phys. Rev., 72, p. 014452Pecharsky, V.K., Gschneidner, K.A., (1999) J. Magn. Magn. Mater., 200 (1-3), p. 44Duc, N.H., Anh, T.K.D., Brommer, P.E., (2002) Physica, 319 (1-4), p. 1Singh Niraj, K., Suresh, K.G., Nigam, A.K., (2003) Solid State Commun., 127 (5), p. 373Khmelevskyi, S., Mohn, P., (2000) J. Phys.: Condens. Matter, 12 (45), p. 9453Bloch, D., Ewards, D.M., Shimizu, M., Voiron, J., (1975) J. Phys. F.: Met. Phys., 5 (6), p. 1217Inoue, J., Shimizu, M., (1982) J. Phys. F.: Met. Phys., 12 (8), p. 1811Singh Niraj, K., Kumar, P., Suresh, K.G., Nigam, A.K., Coelho, A.A., Gama, S., (2007) J. Phys.: Condens. Matter, 19 (3), p. 036213Duc, N.H., Hien, T.D., Brommer, P.E., Franse, J.J.M., (1992) J. Magn. Magn. Mater., 104-107, p. 1252Duc, N.H., Brommer, P.E., (1999) Handbook of Magnetic Materials, 12, p. 259Gopal, E.S.R., (1966) Specific Heats at Low TemperaturesBaranov, N.V., Yermakov, A.A., Pirogov, A.N., Proshkin, A.V., Gvasaliya, S.N., Podlesnyak, A., (2006) Phys. Rev., 73 (10), p. 104445Baranov, N.V., Bartashevich, M.I., Goto, T., Yermakov, A.A., Karkin, A.E., Pirogov, A.N., Teplykh, A.E., (1997) J. Alloys Compounds, 252 (1-2), p. 32Baranov, N.V., Yermakov, A.A., Pirogov, A.N., Teplykh, A.E., Inoue, K., Yu, H., (1999) Physica, 269 (3-4), p. 284Han, Z., Hua, Z., Wang, D., Zhang, C., Gu, B., Du, Y., (2006) J. Magn. Magn. Mater., 302 (1), p. 10
How warm Gulf Stream water sustains a cold underwater waterfall
No full text© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Semper, S., Glessmer, M., Våge, K., & Pickart, R. How warm Gulf Stream water sustains a cold underwater waterfall. Frontiers for Young Minds, 10, (2022): 765740, https://doi.org/10.3389/frym.2022.765740.The most famous ocean current, the Gulf Stream, is part of a large system of currents that brings warm water from Florida to Europe. It is a main reason for northwestern Europe’s mild climate. What happens to the warm water that flows northward, since it cannot just pile up? It turns out that the characteristics of the water change: in winter, the ocean warms the cold air above it, and the water becomes colder. Cold seawater, which is heavier than warm seawater, sinks down to greater depths. But what happens to the cold water that disappears from the surface? While on a research ship, we discovered a new ocean current that solves this riddle. The current brings the cold water to an underwater mountain ridge. The water spills over the ridge as an underwater waterfall before it continues its journey, deep in the ocean, back toward the equator.Support for this work was provided by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 101022251 (SS), the Trond Mohn Foundation Grant BFS2016REK01 (SS and KV), and the U.S. National Science Foundation Grants OCE-1558742 and OCE-1259618 (RP)
Tuning of PID controllers for water networks—different approaches
No full textBetter operational control of water networks can help reduce leakage, maintain pressure, and control flow. Proportional integral derivative (PID) controllers, with proper fine-tuning, can help water utility operators achieve targets faster without creating undue transients. The authors compared three tuning methods, in different test situations, involving flow and level control to different reservoirs. Although target values were reached with all three tuning methods, the methods’ performances varied significantly. The lowest performer among the three was the method most widely used in the industry—standard tuning by the Ziegler-Nichols method. Achieving better results was offline tuning by genetic algorithms. Achieving the best control, though, was a fuzzy logic–based online tuning approach—the FZPID controller. The FZPID controller had fewer overshoots and took significantly less time to tune the gains for each problem. This new tuning approach for PID controllers can be applied to a variety of problems and can increase the performance of water networks of any size and structur
Time-averaged profiles and spatial maps of ocean currents from shipboard ADCP measurements at three North Atlantic seamounts between 2004 and 2015
No full textAuthor affiliations:
Mohn, Christian: Department of Bioscience, Aarhus University, Denmark;
Christiansen, Bernd: Institute for Hydrobiology and Fisheries Science, University of Hamburg;
Denda, Anneke: Institute for Hydrobiology and Fisheries Science, University of Hamburg;
Christiansen, Svenja: GEOMAR - Helmholtz Centre for Ocean Research Kiel;
Kaufmann, Manfred: CIIMAR-Madeira;
Peine, Florian: Institute for Biosciences, University of Rostock
Springer, Barbara: Institute for Biosciences, University of Rostock
Turnewitsch, Robert: Scottish Association for Marine Science, UK
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The dataset consists of single profiles and spatially regridded maps of shipboard ADCP data from cruises to Ampère Seamount, Senghor Seamount and Seine Seamount in the North Atlantic.
Profile data:
2 minute ensemble averaged profiles of horizontal velocity components (u, v), acoustic backscatter and percent good. The profile data is derived from fully processed and time averaged single ping raw data. Processing was conducted with the CODAS ADCP postprocessing package (https://currents.soest.hawaii.edu/docs/adcp_doc/codas_doc/index.html). Parameters are provided in a column-oriented text format (one column for each parameter). Parameters include: Date (yy-mm-dd), Time (HH:MM:SS), Decimal Day, Longitude (°), Latitude (°), Depth (m), U (m/s), V (m/s), Echo Amplitude (Raw Counts), Percent Good.
Available profile data files:
ampere2009_p384_os75_profiles.dat (Sampling year: 2009, Cruise: RV Poseidon 384, Instrument: Ocean Surveyor 75 kHz)
ampere2010_m832_os38_profiles.dat (Sampling year: 2010, Cruise: RV Meteor 83-2, Instrument: Ocean Surveyor 38 kHz)
ampere2010_m832_os75_profiles.dat (Sampling year: 2010, Cruise: RV Meteor 83-2, Instrument: Ocean Surveyor 75 kHz)
senghor2009_m793_os38_profiles.dat (Sampling year: 2009, Cruise: RV Meteor 79-3, Instrument: Ocean Surveyor 38 kHz)
senghor2013_p446_os75_profiles.dat (Sampling year: 2013, Cruise: RV Poseidon 446, Instrument: Ocean Surveyor 75 kHz)
senghor2015_msm49_os75_profiles.dat (Sampling year: 2015, Cruise: RV Maria S Merian 49, Instrument: Ocean Surveyor 75 kHz)
seine2004_d282_os75_profiles.dat (Sampling year: 2004, Cruise: RV Discovery 282, Instrument: Ocean Surveyor 75 kHz)
seine2009_p384_os75_profiles.dat (Sampling year: 2009, Cruise: RV Poseidon 384, Instrument: Ocean Surveyor 75 kHz)
Spatial maps:
ADCP velocity profiles were spatially re-gridded for each depth bin in an optimal way using the Matlab interface of the DIVA optimal interpolation and error analysis toolbox (http://modb.oce.ulg.ac.be/mediawiki/index.php/DIVA). The size of the target grid was set to 30 arc seconds (1/120° or approximately 0.5 nautical miles) in latitude and longitude. The spatial correlation length scale was set to 0.2°, which corresponds to a characteristic seamount length scale in all areas. The signal to noise ratio was set to a constant value of order unity (1) to minimize numerical noise in the gridded velocities caused by the spatial resolution mismatch between along- and cross-track ADCP data. The relative error is based on a covariance function and provides confidence estimates for the DIVA interpolated velocity fields. The 30 arc second Smith and Sandwell global topography data set V17.1 was used for masking in areas, where the bottom topography intersects depth levels. Gridded data are provided in the self-describing, platform-independent NetCDF format.
Gridded data files:
ampere2009_p384_os75_gridded.nc
ampere2010_m832_os38_gridded.nc
ampere2010_m832_os75_gridded.nc
senghor2009_m793_os38_gridded.nc
senghor2013_p446_os75_gridded.nc
senghor2015_msm49_os75_gridded.nc
seine2004_d282_os75_gridded.nc
seine2009_p384_os75_gridded.n
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