References of "Stevens, M"
     in
Bookmark and Share    
Full Text
See detailCICES going Local : Ecosystem Services Classification Adapted for a Highly Populated Country
Turkelboom, Francis; Raquez, Perrine; Dufrêne, Marc ULg et al

in Jacobs, S.; Keune, H.; Dendoncker, N. (Eds.) Belgium Ecosystem Services – Global Issues Local Practices (2013)

Detailed reference viewed: 48 (10 ULg)
See detailTitan airglow: FUV and EUV 2009 UVIS spectra of airglow during day, night and eclipse
Ajello, J.M.; Stevens, M.; West, R. et al

Conference (2012, January)

Detailed reference viewed: 2 (0 ULg)
See detailTitan Airglow Spectra from Cassini UVIS
Ajello, J. M.; Gustin, Jacques ULg; Stevens, M. et al

Conference (2007, December 01)

We present the first UV airglow observations of Titan's atmosphere by the Ultraviolet Imaging Spectrograph (UVIS) on Cassini. The known UV emissions of Titan have been examined with higher spectral ... [more ▼]

We present the first UV airglow observations of Titan's atmosphere by the Ultraviolet Imaging Spectrograph (UVIS) on Cassini. The known UV emissions of Titan have been examined with higher spectral resolution (0.4 nm FWHM) by the Cassini UVIS than in the past by the Voyager Ultraviolet Spectrometer (UVS) (3.0 nm FWHM). The UVIS observations, confirming Voyager UVS results, have shown that molecular nitrogen is the major constituent of the upper atmosphere of Titan. Using one spectral channel in the EUV from 56--118 nm and one in the FUV from 112--191 nm, the UVIS observed the disk on 13 December, 2004. The combined EUV and FUV spectral region is a probe of the stratosphere-mesosphere-thermosphere-exosphere region from about 300--2000 km. The EUV spectrum consists of three band systems of N2 (b {1}Πu, b' {1}Σu+, c{4'} {1}Σ{u+}--X {1}Σ{g+}), while the FUV spectrum consists of one N2 (a {1}Πg--X {1}Σ{g+}). The UVIS observations reveal that the c{4'}(0)--X(0) vibrational band near 95.8 nm is suppressed, and that N \sc{i} multiplets near 95.32 and 96.45 nm are present instead. Magnetospheric particle excitation is weak on this orbit, since the nightside EUV spectrum shows no observable N2 emission features and only H Lyman-β. The absence of significant darkside emission demonstrates that nitrogen emissions are predominantly excited on this orbit by photoelectrons near 900 km in the thermosphere. Above 145 nm most of the observed signal is due to sunlight reflected by N2 in the Titan mesosphere-stratosphere and modified by aerosol and hydrocarbon absorption. Mixing ratios of C2H2, C4H2, C2H4 and tholins have been derived from the reflected sunlight emission between 145 and 190 nm, using a Rayleigh scattering model. Assuming that the energy deposition at these wavelengths occurs near 300 km, these mixing ratios are in good agreement with recent photochemical models and previous Voyager observations in the IR. We also present the first geometric albedo measurement of Titan from 150--190 nm. [less ▲]

Detailed reference viewed: 15 (0 ULg)
Peer Reviewed
See detailSocial behaviour of testosterone-injected male ducklings in the presence of oestrogen-treated females.
Balthazart, Jacques ULg; Stevens, M.

in Behaviour (1976), 57(3-4), 288-306

Detailed reference viewed: 3 (0 ULg)
Full Text
Peer Reviewed
See detailEffects of testosterone propionate on the social behaviour of groups of male comestic ducklings Anas platyrhynchos L.
Balthazart, Jacques ULg; Stevens, M.

in Animal behaviour (1975), 23(4), 926-31

One-month old testosterone-injected ducklings were observed in groups of three males and their social behaviour compared to that of oil-injected control birds. Most elements of adult sexual behaviour and ... [more ▼]

One-month old testosterone-injected ducklings were observed in groups of three males and their social behaviour compared to that of oil-injected control birds. Most elements of adult sexual behaviour and one pattern of aggressive behaviour (chest fight) occurred more frequently in the experimental animals. It was shown that the same hormonal treatment induces different behavioural responses in different animals. Unlike previous studies, no social displays were observed in the testosterone-injected ducklings. Possible explanations of this fact are discussed. [less ▲]

Detailed reference viewed: 8 (0 ULg)