31 research outputs found
Nova light curves from the Solar Mass Ejection Imager (SMEI) - II. The extended catalogue
We present the results from observing nine Galactic novae in eruption with the Solar Mass Ejection Imager (SMEI) between 2004 and 2009. While many of these novae reached peak magnitudes that were either at or approaching the detection limits of SMEI, we were still able to produce light curves that in many cases contained more data at and around the initial rise, peak, and decline than those found in other variable star catalogs. For each nova, we obtained a peak time, maximum magnitude, and for several an estimate of the decline time (t2). Interestingly, although of lower quality than those found in Hounsell et al. (2010a), two of the light curves may indicate the presence of a pre-maximum halt. In addition the high cadence of the SMEI instrument has allowed the detection of low amplitude variations in at least one of the nova light curves
Correlations among biodiversity, biomass and other plant community parameters using the phytosociological approach: A case study from the south-eastern Alps
The present study deals with the grassland complex of communities which may be found on the limestones in the southeastern
Alps; these communities show in fact a particular interest for their high biodiversity degree and for their importance
for the traditional land-use economy of the south-European mountain regions. Phytosociological releve´s corresponding to
well-defined plant associations have been used in order to get information on the relationships among plant species diversity,
biomass, chorotypes, pollination types, functional strategies and soil characteristics. The analysis was carried out both along
an altitudinal and a soil evolution gradient. The analysis of the correlations among the variables and the application of the
principal component analysis shows a positive correlation between soil parameters and biomass, eurichory, anemogamy and
C- and R-strategies; on the contrary, a negative correlation among stenochory, entomogamy and S-strategy with the soil
evolution seems to be present. This article shows how the phytosociological approach can be used to get information and
knowledge on the correlations between several variables useful to understand the complex nature of the plant communities in
order to support management plans