512 research outputs found
lnsect fauna of selected polypore fungi on birch stems in northern Bohemia
Fauna of polypore fungi Fornes fornentarius (L. x Fries) Kicks, Piptoporus betulinus (Bull. ex Fr.) F. Karsten, Fornitopsis pinicola (Swatr ex Fr.) P. Karsten of the birch stem, consisted of 55 insect species. The following species were dominant: Diaperis boleti F. 34.8%, Aridius nodifer West. 19.9%, Bolitophagus reticulatus L. 10.9%, Epuraea variegata (Herbst.) 6.3%, Gyrophaena boleti (L.) 5%, Cis jacquernarti MelliĂ© 4.9%, Atheta fungi (Gras) 3.5%, Atheta crassicornis (F.) 2.8% and moth Archinemapogon yildizae Kocak 2.1 %. A. nodifer (Latridiidae) is a ubiquitous mycetophagous species which in our conditions prefers F. pinicola and has a significant position in the fauna of F. betulinus. Thunes (1994) reports C. jacquermarti only from pine forest, where it formed 54.6% on sporocarps of F. fornentarius while only 1.3% on F. betulinus. In our collections made in birch stands it preferred multiyear sporocarps of F. pinicola and F. fomentarius to P. betulinus. In the Czech Republic it is generally common in deciduous forests especially on F. fornentarius, often simultaneously with C. alter. This can lead to the conclusion that it is the sporocarp of decaying fungus species which is decisive rather than the type of forest (Paviour-Smith 1960, Lawrence 1973, JelĂnek 1990). Dominant representation of D. boleti species (34.8%) has been registered with an evident linkage to P. betulinus (50.6%) and F. fornentarius (31.1 %) and B. reticulatus with prevailing bond to F: fornentarius (46.3%). Butterfly caterpillar fauna showed a limited species spectrum, yet its representatives occurred in al1 sporocarps, F. betulinus being generally preferred.
Key words: Birch, Betula verrucosa, Fomes fornentarius, Piptoporus betulinus, Fornitopsis pinicola, Insect fauna.Fauna of polypore fungi Fornes fornentarius (L. x Fries) Kicks, Piptoporus betulinus (Bull. ex Fr.) F. Karsten, Fornitopsis pinicola (Swatr ex Fr.) P. Karsten of the birch stem, consisted of 55 insect species. The following species were dominant: Diaperis boleti F. 34.8%, Aridius nodifer West. 19.9%, Bolitophagus reticulatus L. 10.9%, Epuraea variegata (Herbst.) 6.3%, Gyrophaena boleti (L.) 5%, Cis jacquernarti MelliĂ© 4.9%, Atheta fungi (Gras) 3.5%, Atheta crassicornis (F.) 2.8% and moth Archinemapogon yildizae Kocak 2.1 %. A. nodifer (Latridiidae) is a ubiquitous mycetophagous species which in our conditions prefers F. pinicola and has a significant position in the fauna of F. betulinus. Thunes (1994) reports C. jacquermarti only from pine forest, where it formed 54.6% on sporocarps of F. fornentarius while only 1.3% on F. betulinus. In our collections made in birch stands it preferred multiyear sporocarps of F. pinicola and F. fomentarius to P. betulinus. In the Czech Republic it is generally common in deciduous forests especially on F. fornentarius, often simultaneously with C. alter. This can lead to the conclusion that it is the sporocarp of decaying fungus species which is decisive rather than the type of forest (Paviour-Smith 1960, Lawrence 1973, JelĂnek 1990). Dominant representation of D. boleti species (34.8%) has been registered with an evident linkage to P. betulinus (50.6%) and F. fornentarius (31.1 %) and B. reticulatus with prevailing bond to F: fornentarius (46.3%). Butterfly caterpillar fauna showed a limited species spectrum, yet its representatives occurred in al1 sporocarps, F. betulinus being generally preferred.
Key words: Birch, Betula verrucosa, Fomes fornentarius, Piptoporus betulinus, Fornitopsis pinicola, Insect fauna.Fauna of polypore fungi Fornes fornentarius (L. x Fries) Kicks, Piptoporus betulinus (Bull. ex Fr.) F. Karsten, Fornitopsis pinicola (Swatr ex Fr.) P. Karsten of the birch stem, consisted of 55 insect species. The following species were dominant: Diaperis boleti F. 34.8%, Aridius nodifer West. 19.9%, Bolitophagus reticulatus L. 10.9%, Epuraea variegata (Herbst.) 6.3%, Gyrophaena boleti (L.) 5%, Cis jacquernarti MelliĂ© 4.9%, Atheta fungi (Gras) 3.5%, Atheta crassicornis (F.) 2.8% and moth Archinemapogon yildizae Kocak 2.1 %. A. nodifer (Latridiidae) is a ubiquitous mycetophagous species which in our conditions prefers F. pinicola and has a significant position in the fauna of F. betulinus. Thunes (1994) reports C. jacquermarti only from pine forest, where it formed 54.6% on sporocarps of F. fornentarius while only 1.3% on F. betulinus. In our collections made in birch stands it preferred multiyear sporocarps of F. pinicola and F. fomentarius to P. betulinus. In the Czech Republic it is generally common in deciduous forests especially on F. fornentarius, often simultaneously with C. alter. This can lead to the conclusion that it is the sporocarp of decaying fungus species which is decisive rather than the type of forest (Paviour-Smith 1960, Lawrence 1973, JelĂnek 1990). Dominant representation of D. boleti species (34.8%) has been registered with an evident linkage to P. betulinus (50.6%) and F. fornentarius (31.1 %) and B. reticulatus with prevailing bond to F: fornentarius (46.3%). Butterfly caterpillar fauna showed a limited species spectrum, yet its representatives occurred in al1 sporocarps, F. betulinus being generally preferred.
Key words: Birch, Betula verrucosa, Fomes fornentarius, Piptoporus betulinus, Fornitopsis pinicola, Insect fauna
Assessment of production zones modelling accuracy based on satellite imaging and yield measurement of selected agriculture plot
ArticleCurrently, remote sensing or yield monitor equipment offer possibilities how to
estimate productivity of the agriculture field. That is why the main aim of this study is to assess
how the latest satellite images from vegetation season and final yield data from combine harvester
can be used to predict yield and to assess site-specific zones productivity. The study is focused
on the accuracy of these systems for the field productivity estimation. The 24.7 ha experimental
field is located near to Vendoli village (the Czech Republic) and it is cultivated by conventional
agricultural practices with emphasis on typical agricultural crops growing in the Czech Republic
(winter wheat, spring barley and winter rape). The results showed that both methods of estimation
can be used for yield prediction. Nevertheless, each of them need specific processing and has
typical limitations
Winter wheat, winter rape and poppy crop growth evaluation with the help of remote and proximal sensing measurements
Monitoring of agricultural crops with the help of remote and proximal sensors during
the growing season plays important role for site-specific management decisions. Winter wheat,
winter rape and poppy are representatives of typical agricultural crops from the family Poacea,
Brassicaceae and Papaveraceae, growing in relative dry area of RakovnĂk district in the Czech
Republic. Ten Sentinel 2 satellite images acquired during vegetation season of the crops were
downloaded and processed. Crops were monitored with the help of unmanned aerial vehicles
(UAV) equipped with consumer grade Red Green Blue (RGB) camera and multispectral (MS)
MicaSense RedEdge MX camera. In-field variability was assessed by computing RGB-based
vegetation indices Triangular Greenness Index (TGI), Green Leaf Index (GLI) and Visible
Atmospherically Resistant Index (VARI) and commonly used vegetation indices as Normalised
Difference Vegetation Index (NDVI) and Green NDVI (GNDVI). The results derived from
satellite and UAV images were supported with in-situ measurements of hand-held GreenSeeker
and Chlorophyll Meter Content sensors. The study showed the usability of individual vegetation
indices, especially the TGI index for chlorophyll content estimation, and VARI index for green
vegetation fraction detection and leaf area index estimation, in comparison with selected handheld devices. The results showed as well that leaf properties and canopy structure of typical
characteristics of selected families can significantly influence the spectral response of the crops
detected in different phenological stages
Drawing Planar Graphs with a Prescribed Inner Face
Given a plane graph (i.e., a planar graph with a fixed planar embedding)
and a simple cycle in whose vertices are mapped to a convex polygon, we
consider the question whether this drawing can be extended to a planar
straight-line drawing of . We characterize when this is possible in terms of
simple necessary conditions, which we prove to be sufficient. This also leads
to a linear-time testing algorithm. If a drawing extension exists, it can be
computed in the same running time
Searching for galactic sources in the Swift GRB catalog
Since the early 1990s Gamma Ray Bursts have been accepted to be of
extra-galactic origin due to the isotropic distribution observed by BATSE and
the redshifts observed via absorption line spectroscopy. Nevertheless, upon
further examination at least one case turned out to be of galactic origin. This
particular event presented a Fast Rise, Exponential Decay (FRED) structure
which leads us to believe that other FRED sources might also be Galactic. This
study was set out to estimate the most probable degree of contamination by
galactic sources that certain samples of FREDs have. In order to quantify the
degree of anisotropy the average dipolar and quadripolar moments of each sample
of GRBs with respect to the galactic plane were calculated. This was then
compared to the probability distribution of simulated samples comprised of a
combination of isotropically generated sources and galactic sources. We observe
that the dipolar and quadripolar moments of the selected subsamples of FREDs
are found more than two standard deviations outside those of random
isotropically generated samples.The most probable degree of contamination by
galactic sources for the FRED GRBs of the Swift catalog detected until February
2011 that do not have a known redshift is about 21 out of 77 sources which is
roughly equal to 27%. Furthermore we observe, that by removing from this sample
those bursts that may have any type of indirect redshift indicator and multiple
peaks gives the most probable contamination increases up to 34% (17 out of 49
sources). It is probable that a high degree of contamination by galactic
sources occurs among the single peak FREDs observed by Swift.Comment: Published to A&A, 4 pages, 5 figures, this arXiv version includes
appended table with all the bursts considered in this stud
Comparing RGB - based vegetation indices from UAV imageries to estimate hops canopy area
Remote estimation of hops plants in hop gardens is imperative in field of precision
agriculture, because of precise imaging of hop garden structure. Monitoring of hop plant volume
and area can help to predict the condition and yield of hops. In this study, two unmanned aerial
vehicles (UAV) – eBee X senseFly UAV equipped with Red Green Blue (RGB) S.O.D.A. camera
and Vertical Take-Off Landing (VTOL) UAV FireFly6 Pro by BirdsEyeView Aerobotics
equipped with MicaSense RedEdge MX camera were used to acquire images of hop garden at
phenology stage maturity of cones (24 th July) before harvest. Seven commonly used RGB
vegetation indices (VI) were derived from these RGB and multispectral (MS) images after
photogrammetric pre-processing and orthophoto mosaic extraction using Pix4Dmapper software.
Vegetation Indices as the Green Percentage Index (G%), Excess of Green Index (ExGreen),
Green Leaf Index (GLI), Visible Atmospherically Resistant Index (VARI), Red Green Blue
Vegetation Index (RGBVI), Normalised Green Red Difference Index (NGRDI) and Triangular
Greenness Index (TGI) were derived from both data sets. Binary model from each of VI was
derived and threshold value for green vegetation was set. The results showed significant
differences in hop plant area based on the specifications of cameras, especially wavelengths
centres, and design and flight parameters of both UAV types. The comparison of various indices
showed, that ExG and TGI indices has the highest congruity of estimated vegetation indices in
hop garden canopy area for both used cameras. Further processing by Fuzzy Overlay tool proved
high accuracy in green canopy area estimation for ExG and TGI vegetation indices
Fast magnetoacoustic wave trains in magnetic funnels of the solar corona
Context: Fast magneto-acoustic waves are highly dispersive in waveguides, so they can generate quasi-periodic wave trains if a localised, impulsive driver is applied. Such wave trains have been observed in the solar corona and may be of use as a seismological tool since they depend upon the plasma structuring perpendicular to the direction of propagation.
Aims. We extend existing models of magnetoacoustic waveguides to consider the effects of an expanding magnetic field. The funnel geometry employed includes a field-aligned density structure.
Methods: We performed 2D numerical simulations of impulsively generated fast magneto-acoustic perturbations. The effects of the density contrast ratio, density stratification, and spectral profile of the driver upon the excited wave trains were investigated.
Results: The density structure acts as a dispersive waveguide for fast magneto-acoustic waves and generates a quasi-periodic wave train similar to previous models. The funnel geometry leads to generating additional wave trains that propagate outside the density structure. These newly discovered wave trains are formed by the leakage of transverse perturbations, but they propagate upwards owing to the refraction caused by the magnetic funnel.
Conclusions: The results of our funnel model may be applicable to wave trains observed propagating in the solar corona. They demonstrate similar properties to those found in our simulations
Advances on Testing C-Planarity of Embedded Flat Clustered Graphs
We show a polynomial-time algorithm for testing c-planarity of embedded flat
clustered graphs with at most two vertices per cluster on each face.Comment: Accepted at GD '1
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