| 1. |
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| 2. |
- Abelev, Betty, et al.
(author)
-
Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
-
In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
-
Journal article (peer-reviewed)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
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| 3. |
- Abelev, Betty, et al.
(author)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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In: Journal of High Energy Physics. - 1029-8479. ; :11
-
Journal article (peer-reviewed)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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| 4. |
- Abelev, Betty, et al.
(author)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
-
In: Journal of High Energy Physics. - 1029-8479. ; :7
-
Journal article (peer-reviewed)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 5. |
- Angelbratt, Jon, 1981, et al.
(author)
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A new method to detect long term trends of methane (CH4) and nitrous oxide (N2O) total columns measured within the NDACC ground-based high resolution solar FTIR network
- 2011
-
In: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 11:13, s. 6167-6183
-
Journal article (peer-reviewed)abstract
- Total columns measured with the ground-based solar FTIR technique are highly variable in time due to atmospheric chemistry and dynamics in the atmosphere above the measurement station. In this paper, a multiple regression model with anomalies of air pressure, total columns of hydrogen fluoride (HF) and carbon monoxide (CO) and tropopause height are used to reduce the variability in the methane (CH(4)) and nitrous oxide (N(2)O) total columns to estimate reliable linear trends with as small uncertainties as possible. The method is developed at the Harestua station (60 degrees N, 11 degrees E, 600 ma.s.l.) and used on three other European FTIR stations, i.e. Jungfraujoch (47 degrees N, 8 degrees E, 3600 ma.s.l.), Zugspitze (47 degrees N, 11 degrees E, 3000 ma.s.l.), and Kiruna (68 degrees N, 20 degrees E, 400 ma.s.l.). Linear CH(4) trends between 0.13 +/- 0.01-0.25 +/- 0.02% yr(-1) were estimated for all stations in the 1996-2009 period. A piecewise model with three separate linear trends, connected at change points, was used to estimate the short term fluctuations in the CH(4) total columns. This model shows a growth in 1996-1999 followed by a period of steady state until 2007. From 2007 until 2009 the atmospheric CH(4) amount increases between 0.57 +/- 0.22-1.15 +/- 0.17% yr(-1). Linear N(2)O trends between 0.19 +/- 0.01-0.40 +/- 0.02% yr(-1) were estimated for all stations in the 1996-2007 period, here with the strongest trend at Harestua and Kiruna and the lowest at the Alp stations. From the N(2)O total columns crude tropospheric and stratospheric partial columns were derived, indicating that the observed difference in the N(2)O trends between the FTIR sites is of stratospheric origin. This agrees well with the N(2)O measurements by the SMR instrument onboard the Odin satellite showing the highest trends at Harestua, 0.98 +/- 0.28% yr(-1), and considerably smaller trends at lower latitudes, 0.27 +/- 0.25% yr(-1). The multiple regression model was compared with two other trend methods, the ordinary linear regression and a Bootstrap algorithm. The multiple regression model estimated CH(4) and N(2)O trends that differed up to 31% compared to the other two methods and had uncertainties that were up to 300% lower. Since the multiple regression method were carefully validated this stresses the importance to account for variability in the total columns when estimating trend from solar FTIR data.
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| 6. |
- Baron, P., et al.
(author)
-
AMATERASU: Model for atmospheric TeraHertz Radiation analysis and simulation
- 2008
-
In: Journal of the National Institute of Information and Communications Technology. - 1349-3205. ; 55:1, s. 109-121
-
Journal article (peer-reviewed)abstract
- We describe the current status of the Advanced Model for Atmospheric TeraHertz Radiation Analysis and Simulation (AMATERASU) that is being developed in the framework of the NICT THz project. This code aims to be used for studying the insterest of the THz frequency region for atmospheric remote sensing, communication systems and estimate the impact of the THz thermal atmospheric emission in the Earth energy budget. This paper presents the first stage of the model development that concerns a non scattering and a horizontal homogeneous atmosphere, e.g., the geophysical parameters are only altitude dependent. A scattering module is being developed but it is presented in an other paper in this issue. The model is based on the Microwave Observation and Lines Estimation and REtrieval code (MOLIERE). The absorption coefficient module has been modified in order to extend the frequency coverage from the submillimeter wavelength to the near InfraRed region. A new radiative transfer module has been implemented that can handle the different types of optical paths and any location for the receiver. AMATERASU includes the original MOLIERE instrument simulator and retrieval codes. The validation methodology is discussed and some examples of the current applications are given. The next steps of the development are presented in the conclusion including the modeling of the horizontal inhomogeneties in the atmopshere.
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| 7. |
- Baron, P., et al.
(author)
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HO2 measurements in the stratosphere and the mesosphere from the sub-millimetre limb sounder Odin/SMR
- 2009
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In: International Journal of Remote Sensing. - : Informa UK Limited. - 1366-5901 .- 0143-1161. ; 30:15-16, s. 4195-4208
-
Journal article (peer-reviewed)abstract
- This paper presents observations of the hydroperoxy radical (HO 2 ) performed by the Odin/SMR instrument from the middle stratosphere to the upper mesosphere (35-90 km). The data set covers the period from October 2003 to December 2005 on a basis of one observation period of 24 hours each month. Odin/SMR can provide two zonal maps of HO 2 per day, with a vertical resolution of 10 km. The non-standard processing applied to the retrievals is described. The consistency between HO 2 observations from three periods in August 2004 demonstrates the robustness of the retrieval method. It also shows that the measurements are sensitive enough to detect changes in the middle and upper mesosphere. The retrieval needs further improvements for studying stratospheric variations. © 2009 Taylor & Francis.
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| 8. |
- Baron, P., et al.
(author)
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Observation of horizontal winds in the middle-atmosphere between 30 degrees S and 55 degrees N during the northern winter 2009-2010
- 2013
-
In: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 13:12, s. 6049-6064
-
Journal article (peer-reviewed)abstract
- Although the links between stratospheric dynamics, climate and weather have been demonstrated, direct observations of stratospheric winds are lacking, in particular at altitudes above 30 km. We report observations of winds between 8 and 0.01 hPa (similar to 35-80 km) from October 2009 to April 2010 by the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station. The altitude range covers the region between 35-60 km where previous space-borne wind instruments show a lack of sensitivity. Both zonal and meridional wind components were obtained, though not simultaneously, in the latitude range from 30 degrees S to 55 degrees N and with a single profile precision of 7-9 ms(-1) between 8 and 0.6 hPa and better than 20 ms(-1) at altitudes above. The vertical resolution is 5-7 km except in the upper part of the retrieval range (10 km at 0.01 hPa). In the region between 1-0.05 hPa, an absolute value of the mean difference 5 ms(-1)). In the mesosphere, SMILES and ECMWF zonal winds exhibit large differences (>20 ms(-1)), especially in the tropics. We illustrate our results by showing daily and monthly zonal wind variations, namely the semi-annual oscillation in the tropics and reversals of the flow direction between 50-55 degrees N during sudden stratospheric warmings. The daily comparison with ECMWF winds reveals that in the beginning of February, a significantly stronger zonal westward flow is measured in the tropics at 2 hPa compared to the flow computed in the analysis (difference of similar to 20 ms(-1)). The results show that the comparison between SMILES and ECMWF winds is not only relevant for the quality assessment of the new SMILES winds, but it also provides insights on the quality of the ECMWF winds themselves. Although the instrument was not specifically designed for measuring winds, the results demonstrate that space-borne sub-mm wave radiometers have the potential to provide good quality data for improving the stratospheric winds in atmospheric models.
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| 9. |
- Baron, P., et al.
(author)
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The Level 2 research product algorithms for the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES)
- 2011
-
In: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 4, s. 2105-2124
-
Journal article (peer-reviewed)abstract
- This paper describes the algorithms of the level-2 research (L2r) processing chain developed for the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES). The chain has been developed in parallel to the operational chain for conducting researches on calibration and retrieval algorithms. L2r chain products are available to the scientific community. The objective of version 2 is the retrieval of the vertical distribution of trace gases in the altitude range of 18–90 km. A theoretical error analysis is conducted to estimate the retrieval feasibility of key parameters of the processing: line-of-sight elevation tangent altitudes (or angles), temperature and ozone profiles. While pointing information is often retrieved from molecular oxygen lines, there is no oxygen line in the SMILES spectra, so the strong ozone line at 625.371 GHz has been chosen. The pointing parameters and the ozone profiles are retrieved from the line wings which are measured with high signal to noise ratio, whereas the temperature profile is retrieved from the optically thick line center. The main systematic component of the retrieval error was found to be the neglect of the non-linearity of the radiometric gain in the calibration procedure. This causes a temperature retrieval error of 5–10 K. Because of these large temperature errors, it is not possible to construct a reliable hydrostatic pressure profile. However, as a consequence of the retrieval of pointing parameters, pressure induced errors are significantly reduced if the retrieved trace gas profiles are represented on pressure levels instead of geometric altitude levels. Further, various setups of trace gas retrievals have been tested. The error analysis for the retrieved HOCl profile demonstrates that best results for inverting weak lines can be obtained by using narrow spectral windows.
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| 10. |
- Barret, B., et al.
(author)
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Intercomparisons of trace gases profiles from the Odin/SMR and Aura/MLS limb sounders
- 2006
-
In: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 111:D21
-
Journal article (peer-reviewed)abstract
- This paper presents the intercomparison of O(3), HNO(3), ClO, N(2)O and CO profiles measured by the two spaceborne microwave instruments MLS ( Microwave Limb Sounder) and SMR ( Submillimetre Radiometer) on board the Aura and Odin satellites, respectively. We compared version 1.5 level 2 data from MLS with level 2 data produced by the French data processor version 222 and 225 and by the Swedish data processor version 2.0 for several days in September 2004 and in March 2005. For the five gases studied, an overall good agreement is found between both instruments. Most of the observed discrepancies between SMR and MLS are consistent with results from other intercomparison studies involving MLS or SMR. O(3) profiles retrieved from the SMR 501.8 GHz band are noisier than MLS profiles but mean biases between both instruments do not exceed 10%. SMR HNO(3) profiles are biased low relative to MLS's by similar to 30% above the profile peak. In the lower stratosphere, MLS ClO profiles are biased low by up to 0.3 ppbv relative to coincident SMR profiles, except in the Southern Hemisphere polar vortex in the presence of chlorine activation. N(2)O profiles from both instruments are in very good agreement with mean biases not exceeding 15%. Finally, the intercomparison between SMR and MLS CO profiles has shown a good agreement from the middle stratosphere to the middle mesosphere in spite of strong oscillations in the MLS profiles. In the upper mesosphere, MLS CO concentrations are biased high relative to SMR while negative values in the MLS retrievals are responsible for a negative bias in the tropics around 30 hPa.
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| 11. |
- Belavy, Daniel L, et al.
(author)
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Disc herniations in astronauts: What causes them, and what does it tell us about herniation on earth?
- 2016
-
In: European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. - : Springer Science and Business Media LLC. - 1432-0932. ; 25:1, s. 144-154
-
Research review (peer-reviewed)abstract
- Recent work showed an increased risk of cervical and lumbar intervertebral disc (IVD) herniations in astronauts. The European Space Agency asked the authors to advise on the underlying pathophysiology of this increased risk, to identify predisposing factors and possible interventions and to suggest research priorities.
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| 12. |
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| 13. |
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| 14. |
- Bender, Stefan, et al.
(author)
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Comparison of nitric oxide measurements in the mesosphere and lower thermosphere from ACE-FTS, MIPAS, SCIAMACHY, and SMR
- 2015
-
In: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 8:10, s. 4171-4195
-
Journal article (peer-reviewed)abstract
- We compare the nitric oxide measurements in the mesosphere and lower thermosphere (60 to 150 km) from four instruments: the Atmospheric Chemistry Experiment–Fourier Transform Spectrometer (ACE-FTS), the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY), and the Sub-Millimetre Radiometer (SMR). We use the daily zonal mean data in that altitude range for the years 2004–2010 (ACE-FTS), 2005–2012 (MIPAS), 2008–2012 (SCIAMACHY), and 2003–2012 (SMR).We first compare the data qualitatively with respect to the morphology, focussing on the major features, and then compare the time series directly and quantitatively. In three geographical regions, we compare the vertical density profiles on coincident measurement days. Since none of the instruments delivers continuous daily measurements in this altitude region, we carried out a multi-linear regression analysis. This regression analysis considers annual and semi-annual variability in the form of harmonic terms and inter-annual variability by responding linearly to the solar Lyman-α radiation index and the geomagnetic Kp index. This analysis helps to find similarities and differences in the individual data sets with respect to the inter-annual variations caused by geomagnetic and solar variability.
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| 15. |
- Berthet, G., et al.
(author)
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Nighttime chlorine monoxide observations by the Odin satellite and implications for the ClO/Cl2O2 equilibrium
- 2005
-
In: Geophysical Research Letters. - 1944-8007 .- 0094-8276. ; 32:11, s. 1-5
-
Journal article (peer-reviewed)abstract
- We use measurements of chlorine monoxide (ClO) by the SMR instrument onboard the Odin satellite to study the nighttime thermal equilibrium between ClO and its dimer Cl2O2. Observations performed in the polar vortex during the 2002-2003 Arctic winter showed enhanced amounts of nighttime ClO over a wide range of stratospheric temperatures (185
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| 16. |
- Brohede, Samuel, 1977, et al.
(author)
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Odin stratospheric proxy NOy measurements and climatology
- 2008
-
In: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 8:19, s. 5731-5754
-
Journal article (peer-reviewed)abstract
- Five years of OSIRIS (Optical Spectrograph and InfraRed Imager System) NO2 and SMR (Sub-millimetre and Millimetre Radiometer) HNO3 observations from the Odin satellite, combined with data from a photochemical box model, have been used to construct a stratospheric proxy NOy data set including the gases: NO, NO2, HNO3, 2×N2O5 and ClONO2. This Odin NOy climatology is based on all daytime measurements and contains monthly mean and standard deviation, expressed as mixing ratio or number density, as function of latitude or equivalent latitude (5° bins) on 17 vertical layers (altitude, pressure or potential temperature) between 14 and 46 km. Comparisons with coincident NOy profiles from the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) instrument were used to evaluate several methods to combine Odin observations with model data. This comparison indicates that the most appropriate merging technique uses OSIRIS measurements of NO2, scaled with model NO/NO2 ratios, to estimate NO. The sum of 2×N2O5 and ClONO2 is estimated from uncertainty-based weighted averages of scaled observations of SMR HNO3 and OSIRIS NO2. Comparisons with ACE-FTS suggest the precision (random error) and accuracy (systematic error) of Odin NOy profiles are about 15% and 20%, respectively. Further comparisons between Odin and the Canadian Middle Atmosphere Model (CMAM) show agreement to within 20% and 2 ppb throughout most of the stratosphere except in the polar vortices. The combination of good temporal and spatial coverage, a relatively long data record, and good accuracy and precision make this a valuable NOy product for various atmospheric studies and model assessments.
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| 17. |
- Christensen, Ole Martin, 1984, et al.
(author)
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Tomographic retrieval of water vapour and temperature around polar mesospheric clouds using Odin-SMR
- 2015
-
In: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 8:5, s. 1981-1999
-
Journal article (peer-reviewed)abstract
- A special observation mode of the Odin satellite provides the first simultaneous measurements of water vapour, temperature and polar mesospheric cloud (PMC) brightness over a large geographical area while still resolving both horizontal and vertical structures in the clouds and background atmosphere. The observation mode was activated during June, July and August of 2010 and 2011, and for latitudes between 50 and 82 degrees N. This paper focuses on the water vapour and temperature measurements carried out with Odin's sub-millimetre radiometer (SMR). The tomographic retrieval approach used provides water vapour and temperature between 75 and 90 km with a vertical resolution of about 2.5 km and a horizontal resolution of about 200 km. The precision of the measurements is estimated to 0.2 ppmv for water vapour and 2K for temperature. Due to limited information about the pressure at the measured altitudes, the results have large uncertainties (> 3 ppmv) in the retrieved water vapour. These errors, however, influence mainly the mean atmosphere retrieved for each orbit, and variations around this mean are still reliably captured by the measurements. SMR measurements are performed using two different mixer chains, denoted as frequency mode 19 and 13. Systematic differences between the two frontends have been noted. A first comparison with the Solar Occultation For Ice Experiment instrument (SOFIE) on-board the Aeronomy of Ice in the Mesosphere (AIM) satellite and the Fourier Transform Spectrometer of the Atmospheric Chemistry Experiment (ACE-FTS) on-board SCISAT indicates that the measurements using the frequency mode 19 have a significant low bias in both temperature (> 15 K) and water vapour (> 0.5 ppmv), while the measurements using frequency mode 13 agree with the other instruments considering estimated errors. PMC brightness data is provided by OSIRIS, Odin's other sensor. Combined SMR and OSIRIS data for some example orbits is considered. For these orbits, effects of PMCs on the water vapour distribution are clearly seen. Areas depleted of water vapour are found above layers with PMC, while regions of enhanced water vapour due to ice particle sedimentation are primarily placed between and under the clouds.
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| 18. |
- Clerbaux, C., et al.
(author)
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CO measurements from the ACE-FTS satellite instrument: data analysis and validation using ground-based, airborne and spaceborne observations
- 2008
-
In: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 8, s. 2569-2594
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Journal article (peer-reviewed)abstract
- The Atmospheric Chemistry Experiment (ACE) mission was launched in August 2003 to sound the atmosphere by solar occultation. Carbon monoxide (CO), a good tracer of pollution plumes and atmospheric dynamics, is one of the key species provided by the primary instrument, the ACE-Fourier Transform Spectrometer (ACE-FTS). This instrument performs measurements in both the CO 1-0 and 2-0 ro-vibrational bands, from which vertically resolved CO concentration profiles are retrieved, from the mid-troposphere to the thermosphere. This paper presents an updated description of the ACE-FTS version 2.2 CO data product, along with a comprehensive validation of these profiles using available observations (February 2004 to December 2006). We have compared the CO partial columns with ground-based measurements using Fourier transform infrared spectroscopy and millimeter wave radiometry, and the volume mixing ratio profiles with airborne (both high-altitude balloon flight and airplane) observations. CO satellite observations provided by nadir-looking instruments (MOPITT and TES) as well as limb-viewing remote sensors (MIPAS, SMR and MLS) were also compared with the ACE-FTS CO products. We show that the ACE-FTS measurements provide CO profiles with small retrieval errors (better than 5% from the upper troposphere to 40 km, and better than 10% above). These observations agree well with the correlative measurements, considering the rather loose coincidence criteria in some cases. Based on the validation exercise we assess the following uncertainties to the ACE-FTS measurement data: better than 15% in the upper troposphere (8–12 km), than 30% in the lower stratosphere (12–30 km), and than 25% from 30 to 100 km.
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| 19. |
- Collaboration, The PANDA, et al.
(author)
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Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
- 2016
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In: European Physical Journal A. - : Springer Publishing Company. - 1434-6001 .- 1434-601X. ; 52:10
-
Journal article (peer-reviewed)abstract
- Simulation results for future measurements of electromagnetic proton form factors at P ¯ ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel p¯ p→ e+e- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e.p¯ p→ π+π-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
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| 20. |
- Davis, Kasey N., et al.
(author)
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Mutations in human DNA methyltransferase DNMT1 induce specific genome-wide epigenomic and transcriptomic changes in neurodevelopment
- 2023
-
In: Human Molecular Genetics. - : Oxford University Press. - 0964-6906 .- 1460-2083. ; 32:21, s. 3105-3120
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Journal article (peer-reviewed)abstract
- DNA methyltransferase type 1 (DNMT1) is a major enzyme involved in maintaining the methylation pattern after DNA replication. Mutations in DNMT1 have been associated with autosomal dominant cerebellar ataxia, deafness and narcolepsy (ADCA-DN). We used fibroblasts, induced pluripotent stem cells (iPSCs) and induced neurons (iNs) generated from patients with ADCA-DN and controls, to explore the epigenomic and transcriptomic effects of mutations in DNMT1. We show cell type–specific changes in gene expression and DNA methylation patterns. DNA methylation and gene expression changes were negatively correlated in iPSCs and iNs. In addition, we identified a group of genes associated with clinical phenotypes of ADCA-DN, including PDGFB and PRDM8 for cerebellar ataxia, psychosis and dementia and NR2F1 for deafness and optic atrophy. Furthermore, ZFP57, which is required to maintain gene imprinting through DNA methylation during early development, was hypomethylated in promoters and exhibited upregulated expression in patients with ADCA-DN in both iPSC and iNs. Our results provide insight into the functions of DNMT1 and the molecular changes associated with ADCA-DN, with potential implications for genes associated with related phenotypes.
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| 21. |
- Dupuy, E., et al.
(author)
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Strato-mesospheric Measurements of Carbon Monoxide with the Odin Sub-millimetre Radiometer: Retrieval and First Results
- 2004
-
In: Geophysical Research Letters. - 1944-8007 .- 0094-8276. ; 31:20
-
Journal article (peer-reviewed)abstract
- The Sub-Millimetre Radiometer (SMR) aboard the Odin satellite has been measuring vertical profiles of atmospheric trace gases since August 2001. We present the inversion methodology developed for CO measurements and the first retrieval results. CO can be retrieved from a single scan measurement throughout the middle atmosphere, with a typical resolution of similar to3 km and a relative error of similar to10% to similar to25%. Retrieval results are evaluated through comparison with data from the Whole Atmosphere Community Climate Model (WACCM) and observations of the Improved Stratospheric and Mesospheric Sounder (ISAMS) on board the Upper Atmospheric Research Satellite (UARS). Considering the large natural variability of CO, the SMR retrievals give good confirmation of the WACCM results, with an overall agreement within a factor of 2. ISAMS abundances are higher than SMR mixing ratios by a factor of 5-10 above 0.5 hPa from similar to80degreesS to similar to50degreesN.
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| 22. |
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| 23. |
- Ejiri, M.K., et al.
(author)
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Validation of the Improved Limb Atmospheric Spectrometer-II (ILAS-II) Version 1.4 nitrous oxide and methane profiles
- 2006
-
In: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 111:D22
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Journal article (peer-reviewed)abstract
- This study assesses polar stratospheric nitrous oxide (N(2)O) and methane (CH(4)) data from the Improved Limb Atmospheric Spectrometer-II (ILAS-II) on board the Advanced Earth Observing Satellite-II (ADEOS-II) retrieved by the Version 1.4 retrieval algorithm. The data were measured between January and October 2003. Vertical profiles of ILAS-II volume mixing ratio (VMR) data are compared with data from two balloon-borne instruments, the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS-B) and the MkIV instrument, as well as with two satellite sensors, the Odin Sub-Millimetre Radiometer (SMR) for N(2)O and the Halogen Occultation Experiment (HALOE) for CH(4). Relative percentage differences between the ILAS-II and balloon/satellite data and their median values are calculated in 10-ppbv-wide bins for N(2)O (from 0 to 400 ppbv) and in 0.05-ppmv-wide bins for CH(4) (from 0 to 2 ppmv) in order to assess systematic differences between the ILAS-II and balloon/satellite data. According to this study, the characteristics of the ILAS-II Version 1.4 N(2)O and CH(4) data differ between hemispheres. For ILAS-II N(2)O VMR larger than 250 ppbv, the ILAS-II N(2)O agrees with the balloon/SMR N(2)O within +/- 20% in both hemispheres. The ILAS-II N(2)O in the VMR range from 30-50 to 250 ppbv (corresponding to altitudes of similar to 17-30 km in the Northern Hemisphere (NH, mainly outside the polar vortex) and similar to 13-21 km in the Southern Hemisphere (SH, mainly inside the polar vortex) is smaller by similar to 10-30% than the balloon/SMR N(2)O. For ILAS-II N(2)O VMR smaller than 30 ppbv (>similar to 21 km) in the SH, the differences between the ILAS-II and SMR N(2)O are within +/- 10 ppbv. For ILAS-II CH(4) VMR larger than 1 ppmv (similar to 30 km) and the ILAS-II CH(4) for its VMR smaller than 1 ppmv (>similar to 25 km) only in the NH, are abnormally small compared to the balloon/satellite data.
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| 24. |
- El Amraoui, L., et al.
(author)
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Assimilation of Odin/SMR and O3 and N2O Measurements in a Three-dimensional Chemistry Transport Model
- 2004
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In: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 109:D22, s. 1-9
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Journal article (peer-reviewed)abstract
- A method for assimilating observations of long-lived species such as ozone (O-3) and nitrous oxide (N2O) in a three-dimensional chemistry transport model (3D-CTM) is described. The model is forced by the temperature and wind analyses from the European Centre for Medium-Range Weather Forecasts (ECMWF). The O-3 and N2O fields used in this study are obtained from the Sub-Millimeter Radiometer (SMR) aboard the Odin satellite. The assimilation technique used is the sequential statistical interpolation approach. The parametrization of the error covariance matrix of the model forecast field is described. A sensitivity study of the system parameters is done in terms of the OMF (observation minus forecast) vector also called "innovation'' vector and in terms of the chi(2) (chi-square) test. The effect of the correlation distances is critical for the assimilated field. The RMS ( root mean square) of the OMF for the correlation distances is minimal for values of 1500 km in the meridional direction and 500 km in the zonal direction for both O-3 and N2O. The treatment of the meridional distance as a function of latitude does not reveal an important improvement. The chi(2) diagnostic shows that the asymptotic value of the model error ( the model error of saturation) is optimal for the value of 12.5% for O-3 and 18% for N2O. We demonstrate the applicability of the developed assimilation method for the Odin/SMR data. We also present first results of the assimilation of Odin/SMR ozone and nitrous oxide for the period from 22 December 2001 to 17 January 2002.
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| 25. |
- Enlund, Fredrik, 1968, et al.
(author)
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Altered Notch signaling resulting from expression of a WAMTP1-MAML2 gene fusion in mucoepidermoid carcinomas and benign Warthin's tumors.
- 2004
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In: Experimental cell research. - : Elsevier BV. - 0014-4827 .- 1090-2422. ; 292:1, s. 21-8
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Journal article (peer-reviewed)abstract
- Chromosome translocations in neoplasia commonly result in fusion genes that may encode either novel fusion proteins or normal, but ectopically expressed proteins. Here we report the cloning of a novel fusion gene in a common type of salivary and bronchial gland tumor, mucoepidermoid carcinomas (MEC), as well as in benign Warthin's tumors (WATs). The fusion, which results from a t(11;19)(q21-22;p13) translocation, creates a chimeric gene in which exon 1 of a novel gene of unknown function, designated WAMTP1, is linked to exons 2-5 of the recently identified Mastermind-like Notch coactivator MAML2. In the fusion protein, the N-terminal basic domain of MAML2, which is required for binding to intracellular Notch (Notch ICD), is replaced by an unrelated N-terminal sequence from WAMTP1. Mutation analysis of the N-terminus of WAMTP1-MAML2 identified two regions of importance for nuclear localization (amino acids 11-20) and for colocalization with MAML2 and Notch1 ICD in nuclear granules (amino acids 21-42). Analyses of the Notch target genes HES5 and MASH1 in MEC tumors with and without the WAMTP1-MAML2 fusion revealed upregulation of HES5 and downregulation of MASH1 in fusion positive MECs compared to normal salivary gland tissue and MECs lacking the fusion. These findings suggest that altered Notch signaling plays an important role in the genesis of benign and malignant neoplasms of salivary and bronchial gland origin.
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