Search
Results
-
NOx production by lightning in Hector: first airborne measurements during SCOUT-O3/ACTIVE
(2009)Atmospheric Chemistry and PhysicsDuring the SCOUT-O3/ACTIVE field phase in November–December 2005, airborne in situ measurements were performed inside and in the vicinity of thunderstorms over northern Australia with several research aircraft (German Falcon, Russian M55 Geophysica, and British Dornier-228. Here a case study from 19 November is presented in detail on the basis of airborne trace gas measurements (NO, NOy, CO, O3) and stroke measurements from the German ...Journal Article -
Measuring the specific surface area of snow with X-ray tomography and gas adsorption: comparison and implications for surface smoothness
(2008)Atmospheric Chemistry and PhysicsChemical and physical processes, such as heterogeneous chemical reactions, light scattering, and metamorphism occur in the natural snowpack. To model these processes in the snowpack, the specific surface area (SSA) is a key parameter. In this study, two methods, computed tomography and methane adsorption, which have intrinsically different effective resolutions – molecular and 30 μm, respectively – were used to determine the SSA of similar ...Journal Article -
Representativeness and climatology of carbon monoxide and ozone at the global GAW station Mt. Kenya in equatorial Africa
(2008)Atmospheric Chemistry and PhysicsThe tropics strongly influence the global atmospheric chemistry budget. However, continuous in-situ observations of trace gases are rare especially in equatorial Africa. The WMO Global Atmosphere Watch (GAW) programme aimed to close this gap with the installation of the Mt. Kenya (MKN) baseline station. Here, the first continuous measurements of carbon monoxide (CO) and ozone (O3) at this site covering the period June 2002 to June 2006 ...Journal Article -
Study of b-quark mass effects in multijet topologies with the DELPHI detector at LEP
(2008)The European Physical Journal CThe effect of the heavy b-quark mass on the two, three and four-jet rates is studied using LEP data collected by the DELPHI experiment at the Z peak in 1994 and 1995. The rates of b-quark jets and light quark jets (ℓ=uds) in events with n=2, 3, and 4 jets, together with the ratio of two and four-jet rates of b-quarks with respect to light-quarks, Rn bℓ, have been measured with a double-tag technique using the CAMBRIDGE jet-clustering ...Journal Article -
Formation of ice supersaturation by mesoscale gravity waves
(2005)Atmospheric Chemistry and PhysicsWe investigate the formation and evolution of an ice-supersaturated region (ISSR) that was detected by means of an operational radiosonde sounding launched from the meteorological station of Lindenberg on 21 March 2000, 00:00 UTC. The supersaturated layer was situated below the local tropopause, between 320 and 408 hPa altitude. Our investigation uses satellite imagery from METEOSAT and the Advanced Very High Resolution Radiometer (AVHRR) ...Journal Article -
Measurement of the Mass and Width of the W Boson in e+ e- Collisions at s**(1/2) = 161-GeV - 209-GeV
(2008)The European Physical Journal CA measurement of the W boson mass and width has been performed by the DELPHI collaboration using the data collected during the full LEP2 programme (1996–2000). The data sample has an integrated luminosity of 660 pb-1 and was collected over a range of centre-of-mass energies from 161 to 209 GeV. Results are obtained by applying the method of direct reconstruction of the mass of the W from its decay products in both the W+W-→ℓν̄ℓqq̄’ and ...Journal Article -
Study of W Boson Polarisations and Triple Gauge Boson Couplings in the Reaction e+e- -> W+W- at LEP 2
(2008)The European Physical Journal CA determination of the single W spin density matrix (SDM) elements in the reaction e+e-→W+W-→lνqq̄(l=e/μ) is reported at centre-of-mass energies between 189 and 209 GeV. The data sample used corresponds to an integrated luminosity of 520 pb-1 taken by DELPHI between 1998 and 2000. The single W SDM elements, ρττ’ W± (τ,τ’=± 1 or 0), are determined as a function of the W- production angle with respect to the e- beam direction and are obtained ...Journal Article -
Exploitative and Hierarchical Antagonism in a Cooperative Bacterium
(2005)PLoS BiologySocial organisms that cooperate with some members of their own species, such as close relatives, may fail to cooperate with other genotypes of the same species. Such noncooperation may take the form of outright antagonism or social exploitation. Myxococcus xanthus is a highly social prokaryote that cooperatively develops into spore-bearing, multicellular fruiting bodies in response to starvation. Here we have characterized the nature of ...Journal Article -
JNK1 is not essential for TNF-mediated joint disease
(2004)Arthritis Research & TherapyTumour necrosis factor (TNF) signalling molecules are considered as promising therapeutic targets of antirheumatic therapy. Among them, mitogen-activated protein kinases are thought to be of central importance. Herein, we investigate the role in vivo of TNF-α signalling through c-Jun N-terminal kinase (JNK)1 in destructive arthritis. Human TNF transgenic (hTNFtg) mice, which develop inflammatory arthritis, were intercrossed with JNK1-deficient ...Journal Article -
Recombination in Glomus intraradices, a supposed ancient asexual arbuscular mycorrhizal fungus
(2009)BMC Evolutionary BiologyBackground Arbuscular mycorrhizal fungi (AMF) are important symbionts of most plant species, promoting plant diversity and productivity. This symbiosis is thought to have contributed to the early colonisation of land by plants. Morphological stasis over 400 million years and the lack of an observed sexual stage in any member of the phylum Glomeromycota led to the controversial suggestion of AMF being ancients asexuals. Evidence for ...Journal Article