143 research outputs found
The effect of environmental factors on the mayfly communities of headwater streams in the Pieniny Mountains (West Carpathians)
A study of the species composition of mayfly communities in connection with environmental parameters was made in headwater streams of the Pieniny Mts. The rhithral zone is inhabited maximally by 19 mayfly species. In most of the streams studied the mayfly communities were found to be similar, however the vertical zonation which reflected human impact was visible (NMDS analysis). The main factors responsible for mayfly communities at all the sites studied were stream regulation and organic pollution, followed by type of bottom substrate (pebble and gravel), riparian vegetation (shrubs), pH and water temperature. At undisturbed sites the most important factors were pH, substrate type, distance from the source, current velocity and riparian vegetation (CCA analysis). Analysis of mayfly communities and environmental characteristics in different seasons showed that occurrence of mayfly species varied substantially depending on the season. Only in early spring and autumn do mayfly communities occur which are dependent on many environmental factors, the most significant of which are substrate type, phosphate, distance from source and altitude (CCA analysis)
Successful resuscitation from accidental hypothermia of 11.8°C : where is the lower bound for human beings?
Maximum likelihood estimation for discrete exponential families and random graphs
We characterize the existence of the maximum likelihood estimator for
discrete exponential families. Our criterion is simple to apply as we show in
various settings, most notably for exponential models of random graphs. As an
application, we point out the size of independent identically distributed
samples for which the maximum likelihood estimator exists with high
probability.Comment: 21 pages, minor editorial changes, added connections to the criterion
of Barndorff-Nielsen and linear programmin
Effect of conventional and non-inversion tillage systems on the abundance and some life history traits of carabid beetles (Coleoptera : Carabidae) in winter triticale fields
Riverine ground beetles as indicators of inundation frequency of mountain stream : a case study of the Ochotnica Stream, Southern Poland
Ancyrophora gracilis Leger, 1892 and Actinocephalus permagnus Wellmer, 1910 (Eugregarinorida : Apicomplexa) in natural populations of ground beetles (Coleoptera, Carabidae) : hosts preferences, intensity and seasonal dynamic
Diversity of carabid beetle assemblages (Coleoptera: Carabidae) in a post-industrial slag deposition area
Different responses of epigeic beetles to heavy metal contamination depending on functional traits at the family level
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