183 research outputs found
Thirty years of vegetation dynamics in the Rospuda fen (NE Poland)
Little is known about the vegetation dynamics of fens, and especially of hydrologically undisturbed examples. We described the vegetation of an undisturbed mesotrophic rich fen (percolation mire) in 2006–2008 and 2016 and compared our results with vegetation records from the 1980s to identify any longer-term changes. Eight vegetation types were distinguished. On the whole, the vegetation of the mire has remained very stable throughout the last 30 years. However, detailed comparisons of permanent plots recorded twice in the last ten years indicated an expansion of shrubs in patches of Sphagnum - small sedge vegetation. There were also several less prominent changes in the abundance of particular species in other mire vegetation types: (1) an increase of sedges, reeds and Calliergonella cuspidata at the expense of rich-fen moss species in communities of brown moss - small sedge; (2) a change in composition of the moss layer in pine - birch fen woodland; (3) an increase of reedbed species and reduced Alnus glutinosa abundance in flooded riparian alder woodland; and (4) a decline of wetland herbs and mosses in alder spring fen woodland at the edges of the valley
Catchment-Scale Analysis Reveals High Cost-Effectiveness of Wetland Buffer Zones as a Remedy to Non-Point Nutrient Pollution in North-Eastern Poland
Large-scale re-establishment of wetland buffer zones (WBZ) along rivers is regarded as an effective measure in order to reduce non-point source nitrogen (N) and phosphorus (P) pollution in agricultural catchments. We estimated efficiency and costs of a hypothetical establishment of WBZs along all watercourses in an agricultural landscape of the lower Narew River catchment (north-eastern Poland, 16,444 km2, amounting to 5% of Poland) by upscaling results obtained in five sub-catchments (1087 km2). Two scenarios were analysed, with either rewetting selected wetland polygons that collect water from larger areas (polygonal WBZs) or reshaping and rewetting banks of rivers (linear WBZs), both considered in all ecologically suitable locations along rivers. Cost calculation included engineering works necessary in order to establish WBZs, costs of land purchase where relevant, and compensation costs of income forgone to farmers (needed only for polygonal WBZs). Polygonal WBZs were estimated in order to remove 11%–30% N and 14%–42% P load from the catchment, whereas linear WBZs were even higher with 33%–82% N and 41%–87% P. Upscaled costs of WBZ establishment for the study area were found to be 8.9 M EUR plus 26.4 M EUR per year (polygonal WBZ scenario) or 170.8 M EUR (linear WBZ scenario). The latter value compares to costs of building about 20 km of an express road. Implementation of buffer zones on a larger scale is thus a question of setting policy priorities rather than financial impossibility
Homomorphisms from functional equations: the Goldie equation
The theory of regular variation, in its Karamata and Bojani´c-Karamata/de Haan forms, is long established and makes essential use of the Cauchy functional equation. Both forms are subsumed within the recent theory of Beurling regular variation, developed elsewhere. Various generalizations of the Cauchy equation, including the Gołab–Schinzel functional equation (GS) and Goldie's equation (GBE) below, are prominent there. Here we unify their treatment by algebraicization: extensive use of group structures introduced by Popa and Javor in the 1960s turn all the various (known) solutions into homomorphisms, in fact identifying them 'en passant', and show that (GS) is present everywhere, even if in a thick disguise
Phylogenetic groups, virulence genes and quinolone resistance of integron-bearing Escherichia coli strains isolated from a wastewater treatment plant
We investigated phylogenetic affiliation, occurrence of virulence genes and quinolone resistance in 109 integron-containing strains of Escherichia coli isolated from a wastewater treatment plant. Selection for integron-bearing strains caused a shift toward phylogroup D, which was most numerous, followed by A, B1 and B2. Phylogroups D and B2, both of which are reported to include virulent extraintestinal pathotypes, made up 50.5% of all isolates and were present in every stage of wastewater treatment, including final effluent. Diarrheagenic pathotypes made up 21% of the strains. The average virulence factor genes score was low (1.40) and the range was from 0 to 5. Quinolone and fluoroquinolone resistance was observed in 56.0% and 50.4% of the strains, respectively; however, it was not associated with virulence factor score. Although the average virulence factor score was low, 17.4% of strains had three and more virulence genes. They were isolated mostly from raw sewage, but 30% of them were cultured from final effluent. Release of multiresistant integron-bearing E. coli strains with virulence traits into the environment may create potential threat and be of public health concern
Characterization of Novel Cutaneous Human Papillomavirus Genotypes HPV-150 and HPV-151
DNA from two novel HPV genotypes, HPV-150 and HPV-151, isolated from hair follicles of immuno-competent individuals, was fully cloned, sequenced and characterized. The complete genomes of HPV-150 and HPV-151 are 7,436-bp and 7,386-bp in length, respectively. Both contain genes for at least six proteins, namely E6, E7, E1, E2, L2, L1, as well as a non-coding upstream regulatory region located between the L1 and E6 genes: spanning 416-bp in HPV-150 (genomic positions 7,371 to 350) and 322-bp in HPV-151 (genomic positions 7,213 to 148). HPV-150 and HPV-151 are phylogenetically placed within the Betapapillomavirus genus and are most closely related to HPV-96 and HPV-22, respectively. As in other members of this genus, the intergenic E2-L2 region is very short and does not encode for an E5 gene. Both genotypes contain typical zinc binding domains in their E6 and E7 proteins, but HPV-151 lacks the regular pRb-binding core sequence within its E7 protein. In order to assess the tissue predilection and clinical significance of the novel genotypes, quantitative type-specific real-time PCR assays were developed. The 95% detection limits of the HPV-150 and HPV-151 assays were 7.3 copies/reaction (range 5.6 to 11.4) and 3.4 copies/reaction (range 2.5 to 6.0), respectively. Testing of a representative collection of HPV-associated mucosal and cutaneous benign and malignant neoplasms and hair follicles (total of 540 samples) revealed that HPV-150 and HPV-151 are relatively rare genotypes with a cutaneous tropism. Both genotypes were found in sporadic cases of common warts and SCC and BCC of the skin as single or multiple infections usually with low viral loads. HPV-150 can establish persistent infection of hair follicles in immuno-competent individuals. A partial L1 sequence of a putative novel HPV genotype, related to HPV-150, was identified in a squamous cell carcinoma of the skin obtained from a 64-year old immuno-compromised male patient
Gaia Focused Product Release: Radial velocity time series of long-period variables
The third Gaia Data Release (DR3) provided photometric time series of more
than 2 million long-period variable (LPV) candidates. Anticipating the
publication of full radial-velocity (RV) in DR4, this Focused Product Release
(FPR) provides RV time series for a selection of LPVs with high-quality
observations. We describe the production and content of the Gaia catalog of LPV
RV time series, and the methods used to compute variability parameters
published in the Gaia FPR. Starting from the DR3 LPVs catalog, we applied
filters to construct a sample of sources with high-quality RV measurements. We
modeled their RV and photometric time series to derive their periods and
amplitudes, and further refined the sample by requiring compatibility between
the RV period and at least one of the , , or
photometric periods. The catalog includes RV time series and variability
parameters for 9\,614 sources in the magnitude range , including a flagged top-quality subsample of 6\,093 stars
whose RV periods are fully compatible with the values derived from the ,
, and photometric time series. The RV time series
contain a mean of 24 measurements per source taken unevenly over a duration of
about three years. We identify the great most sources (88%) as genuine LPVs,
with about half of them showing a pulsation period and the other half
displaying a long secondary period. The remaining 12% consists of candidate
ellipsoidal binaries. Quality checks against RVs available in the literature
show excellent agreement. We provide illustrative examples and cautionary
remarks. The publication of RV time series for almost 10\,000 LPVs constitutes,
by far, the largest such database available to date in the literature. The
availability of simultaneous photometric measurements gives a unique added
value to the Gaia catalog (abridged)Comment: 36 pages, 38 figure
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