Both non-rooted submerged vegetation dominated by coontail (Ceratophyllum demersum) and non-roote... more Both non-rooted submerged vegetation dominated by coontail (Ceratophyllum demersum) and non-rooted floating duckweed vegetation (Lemna gibba) can maintain their stable dominance in small ponds and channels. We examined the competitive interactions between them and how Ceratophyllum can sustain its stable state against floating plants in a range of nutrient concentrations. Coontail and duckweed were co-cultured in static and semi-static microcosm experiments, and their impact on the nutrients (N, P, Fe, Mn) in the water column was analysed. Coontail strongly reduced the growth of duckweed under a low nitrogen level (0.2-2 mg N L-1). This reduction seems to be due to the low availability of nutrients in the water as derived from the lower nutrient concentrations in duckweed tissue or high pH in water. High nitrogen levels in semi-static media (5-10 mg N L-1) resulted in an increasingly higher chance to overgrow C. demersum by L. gibba. Field observations revealed that C. demersum dominated over L. gibba in water bodies with total N below 3 mg L-1 , while L. gibba dominance over C. demersum occurred above 5 mg L-1 total N. Ceratophyllum occurrence correlated negatively with total N in the water, while Lemna showed a positive correlation. Furthermore, the occurrence of L. gibba was negatively correlated with the frequency of C. demersum. All findings together support the theory that under a certain nutrient range, rootless submerged macrophytes have a strong potential to inhibit the dominance of floating plants in ponds, ditches and channels, and thus, they stabilize the submerged vegetation state.
The use of gadolinium-based contrasting agents (GBCA) is increasing because of the intensive usag... more The use of gadolinium-based contrasting agents (GBCA) is increasing because of the intensive usage of these agents in magnetic resonance imaging (MRI). Waste-water treatment does not reduce anthropogenic Gd-concentration significantly. Anomalous Gd-concentration in surface waters have been reported worldwide. However, removal of GBCA-s by aquatic macrophytes has still hardly been investigated. Four aquatic plant species (Lemna gibba, Ceratophyllum demersum, Elodea nuttallii, E. canadensis) were investigated as potential biological filters for removal of commonly used but structurally different GBCA-s (Omniscan, Dotarem) from water. These plant species are known to accumulate heavy metals and are used for removing pollutants in constructed wetlands. The Gd uptake and release of the plants was examined under laboratory conditions. Concentration-dependent infiltration of Gd into the body of the macrophytes was measured, however significant bioaccumulation was not observed. The tissue c...
Two closely related alien submerged aquatic plants were introduced in Europe. The new invader (El... more Two closely related alien submerged aquatic plants were introduced in Europe. The new invader (Elodea nuttallii) gradually displaced E. canadensis even at sites where the latter was well-established. The aim of the study was to evaluate the combined effects of environmental factors on several phenotypic characteristics of the two Elodea species, and to relate these phenotypic characteristics to the invasion success of E. nuttallii over E. canadensis. In a factorial design, Elodea plants were grown in aquaria containing five different nitrogen concentrations and incubated at five different light intensities. We used six functional traits (apical shoot relative growth rate (RGR), total shoot RGR, relative elongation, root length, lateral spread, branching degree) to measure the environmental response of the species. We calculated plasticity indexes to express the phenotypic differences between species. Light and nitrogen jointly triggered the development of phenotypic characteristics ...
Algal flora of 12 bog lakes was investigated during the period of March 1995 to August 1999 in Hu... more Algal flora of 12 bog lakes was investigated during the period of March 1995 to August 1999 in Hungary. Of the 129 samples, 624 taxa of algae were identified. Species richness of individual samples ranged between 8 and 107 except the extraordinarily species rich Baláta-tó where 533 algal taxa were observed. Ordination of the samples resulted in five groups: (1) assemblages dominated by chlorococcalean algae and planktonic Cyanoprokaryota; (2) assemblages dominated by flagellates (Dinophyta, Cryptophyta, Euglenophyta, Chrysophyceae, Raphidophyceae); (3) chlorococcalean algae and cyanoprokaryotic assemblages with desmids, cryptophytes, dinoflagellates or euglenophytes as subdominants; (4) assemblages dominated by diatoms and (5) a group of samples where other taxa belonging to Xanthophyta and filamentous green algae dominated. The bogs were typically rich in inorganic N and P, moreover, their water chemical characteristics (including pH and conductivity) were rather uniform. Therefore, other factors than chemical properties were responsible for different flora. The above groups were characteristic to certain types of habitats. In the first group, plankton samples from relatively large pools with considerable open water can be found. The second group included samples taken from small bog pools. The third group contained the periphyton samples from macrophytes, living in bogs with constantly reliable water supply. Samples of group four and five comprised small bogs that occasionally dry up. Periphyton of lakes with Sphagnum belonged exclusively to the fifth group. This study has shown that small bog-pools are often inhabited by different species of flagellates and desmids are not as important as it has been widely believed. Hydrological properties and habitat diversity are the major factors influencing species richness of Hungarian bog-lakes.
1995 ota vegzunk rendszeres algologiai vizsgalatokat egy tipikus laptavon, a Balata tavon. Jelen ... more 1995 ota vegzunk rendszeres algologiai vizsgalatokat egy tipikus laptavon, a Balata tavon. Jelen dolgozatban roviden osszegezzuk a to dinoflagellata florajaval kapcsolatos megfigyeleseinket. A laptavak egyik jellegzetessege az a nagyfoku habitat-diverzitas, melyet a makrofitonok valtozatos terbeli elhelyezkedese idez elő. a nagy előhelyi valtozatossag szamos rendkivul ritka dinoflagellata faj előfordulasat is lehetőve teszi. Vizsgalataink soran 16 dinophyton fajt talaltunk, melyek kozul 13 planktonikus, 3 pedig epifitikus volt. A vegetacios periodus dinoflagellata floraja jelentős mertekben eltert a teli időszaketol. Noha a fajok tobbsege a vegetacios periodusban vett mintakban volt megfigyelhető, e fajok egyedeinek aranya mas taxonokehoz viszonyitva igen alacsony (<10%) volt. Ugyanakkor, nehany jellegzetesen teli szervezetnek tekinthető faj a vizsgalt mintakban nagyobb aranyban volt kepviselve, s nem egyszer dominanciajuk is megfigyelhető volt. A lapok algaflorajanak bemutatasakor a szerzők altalaban a Desmidiales flora gazdagsagat es kulonlegessegeit szoktak kiemelni, mi azonban ugy veljuk, hogy a lapokat az igen jellegzetes, es a mas vizi előhelyeketől markansan elterő dinoflagellata floraval is jellemezhetjuk.
G. Hajós proved that if a finite abelian group is a direct product of its cyclic subsets, then at... more G. Hajós proved that if a finite abelian group is a direct product of its cyclic subsets, then at least one of the factors must be a subgroup. We give a new elementary proof of this theorem based on the special case for p-groups.
Consider the set of closed unit cubes whose edges are parallel to the coordinate unit vectors e,,... more Consider the set of closed unit cubes whose edges are parallel to the coordinate unit vectors e,,...,e" and whose centers are re., 0<|;|*i, in ndimensional Euclidean space. The union of these cubes is called a cross. This cross consists of 2kn + 1 cubes; a central cube together with In arms of length k. A family of translates of a cross whose union is «-dimensional Euclidean space and whose interiors are disjoint is a tiling. Denote the set of translation vectors by L If the vector set L is a vector lattice, then we say that the tiling is a lattice tiling. If every vector of L has rational coordinates, then we say that the tiling is a rational tiling, and, similarly, if every vector of L has integer coordinates, then we say that the tiling is an integer tiling. Is there a noninteger tiling by crosses? In this paper we shall prove that if there is an integer lattice tiling by crosses, if 2kn + 1 is not a prime, and if p > k for every prime divisor p of 2 kn + I, then there is a rational noninteger lattice tiling by crosses and there is an integer nonlattice tiling by crosses. We will illustrate this in the case of a cross with arms of length 2 in 55-dimensional Euclidean space. Throughout, the techniques are algebraic.
... K. Hale Georgia Institute of Technology S. Kobayashi University of California, Berkeley Marvi... more ... K. Hale Georgia Institute of Technology S. Kobayashi University of California, Berkeley Marvin Marcus University of California, Santa Barbara WS Massey ... Differential Equations and Applications VII L. Sabinin, et al., Non-Associative Algebra and Its Application KM Furati, et al ...
In 1961 J. Stein proposed an algorithm to compute the greatest common divisor of two integers. In... more In 1961 J. Stein proposed an algorithm to compute the greatest common divisor of two integers. In this paper we point out that similar algorithms exist in the ring of integers of various quadratic number fields and also in the non-commutative ring of the Hurwitz quaternions. The implementations of the algorithms are straightforward. However the procedures vary from case to case.
Both non-rooted submerged vegetation dominated by coontail (Ceratophyllum demersum) and non-roote... more Both non-rooted submerged vegetation dominated by coontail (Ceratophyllum demersum) and non-rooted floating duckweed vegetation (Lemna gibba) can maintain their stable dominance in small ponds and channels. We examined the competitive interactions between them and how Ceratophyllum can sustain its stable state against floating plants in a range of nutrient concentrations. Coontail and duckweed were co-cultured in static and semi-static microcosm experiments, and their impact on the nutrients (N, P, Fe, Mn) in the water column was analysed. Coontail strongly reduced the growth of duckweed under a low nitrogen level (0.2-2 mg N L-1). This reduction seems to be due to the low availability of nutrients in the water as derived from the lower nutrient concentrations in duckweed tissue or high pH in water. High nitrogen levels in semi-static media (5-10 mg N L-1) resulted in an increasingly higher chance to overgrow C. demersum by L. gibba. Field observations revealed that C. demersum dominated over L. gibba in water bodies with total N below 3 mg L-1 , while L. gibba dominance over C. demersum occurred above 5 mg L-1 total N. Ceratophyllum occurrence correlated negatively with total N in the water, while Lemna showed a positive correlation. Furthermore, the occurrence of L. gibba was negatively correlated with the frequency of C. demersum. All findings together support the theory that under a certain nutrient range, rootless submerged macrophytes have a strong potential to inhibit the dominance of floating plants in ponds, ditches and channels, and thus, they stabilize the submerged vegetation state.
The use of gadolinium-based contrasting agents (GBCA) is increasing because of the intensive usag... more The use of gadolinium-based contrasting agents (GBCA) is increasing because of the intensive usage of these agents in magnetic resonance imaging (MRI). Waste-water treatment does not reduce anthropogenic Gd-concentration significantly. Anomalous Gd-concentration in surface waters have been reported worldwide. However, removal of GBCA-s by aquatic macrophytes has still hardly been investigated. Four aquatic plant species (Lemna gibba, Ceratophyllum demersum, Elodea nuttallii, E. canadensis) were investigated as potential biological filters for removal of commonly used but structurally different GBCA-s (Omniscan, Dotarem) from water. These plant species are known to accumulate heavy metals and are used for removing pollutants in constructed wetlands. The Gd uptake and release of the plants was examined under laboratory conditions. Concentration-dependent infiltration of Gd into the body of the macrophytes was measured, however significant bioaccumulation was not observed. The tissue c...
Two closely related alien submerged aquatic plants were introduced in Europe. The new invader (El... more Two closely related alien submerged aquatic plants were introduced in Europe. The new invader (Elodea nuttallii) gradually displaced E. canadensis even at sites where the latter was well-established. The aim of the study was to evaluate the combined effects of environmental factors on several phenotypic characteristics of the two Elodea species, and to relate these phenotypic characteristics to the invasion success of E. nuttallii over E. canadensis. In a factorial design, Elodea plants were grown in aquaria containing five different nitrogen concentrations and incubated at five different light intensities. We used six functional traits (apical shoot relative growth rate (RGR), total shoot RGR, relative elongation, root length, lateral spread, branching degree) to measure the environmental response of the species. We calculated plasticity indexes to express the phenotypic differences between species. Light and nitrogen jointly triggered the development of phenotypic characteristics ...
Algal flora of 12 bog lakes was investigated during the period of March 1995 to August 1999 in Hu... more Algal flora of 12 bog lakes was investigated during the period of March 1995 to August 1999 in Hungary. Of the 129 samples, 624 taxa of algae were identified. Species richness of individual samples ranged between 8 and 107 except the extraordinarily species rich Baláta-tó where 533 algal taxa were observed. Ordination of the samples resulted in five groups: (1) assemblages dominated by chlorococcalean algae and planktonic Cyanoprokaryota; (2) assemblages dominated by flagellates (Dinophyta, Cryptophyta, Euglenophyta, Chrysophyceae, Raphidophyceae); (3) chlorococcalean algae and cyanoprokaryotic assemblages with desmids, cryptophytes, dinoflagellates or euglenophytes as subdominants; (4) assemblages dominated by diatoms and (5) a group of samples where other taxa belonging to Xanthophyta and filamentous green algae dominated. The bogs were typically rich in inorganic N and P, moreover, their water chemical characteristics (including pH and conductivity) were rather uniform. Therefore, other factors than chemical properties were responsible for different flora. The above groups were characteristic to certain types of habitats. In the first group, plankton samples from relatively large pools with considerable open water can be found. The second group included samples taken from small bog pools. The third group contained the periphyton samples from macrophytes, living in bogs with constantly reliable water supply. Samples of group four and five comprised small bogs that occasionally dry up. Periphyton of lakes with Sphagnum belonged exclusively to the fifth group. This study has shown that small bog-pools are often inhabited by different species of flagellates and desmids are not as important as it has been widely believed. Hydrological properties and habitat diversity are the major factors influencing species richness of Hungarian bog-lakes.
1995 ota vegzunk rendszeres algologiai vizsgalatokat egy tipikus laptavon, a Balata tavon. Jelen ... more 1995 ota vegzunk rendszeres algologiai vizsgalatokat egy tipikus laptavon, a Balata tavon. Jelen dolgozatban roviden osszegezzuk a to dinoflagellata florajaval kapcsolatos megfigyeleseinket. A laptavak egyik jellegzetessege az a nagyfoku habitat-diverzitas, melyet a makrofitonok valtozatos terbeli elhelyezkedese idez elő. a nagy előhelyi valtozatossag szamos rendkivul ritka dinoflagellata faj előfordulasat is lehetőve teszi. Vizsgalataink soran 16 dinophyton fajt talaltunk, melyek kozul 13 planktonikus, 3 pedig epifitikus volt. A vegetacios periodus dinoflagellata floraja jelentős mertekben eltert a teli időszaketol. Noha a fajok tobbsege a vegetacios periodusban vett mintakban volt megfigyelhető, e fajok egyedeinek aranya mas taxonokehoz viszonyitva igen alacsony (<10%) volt. Ugyanakkor, nehany jellegzetesen teli szervezetnek tekinthető faj a vizsgalt mintakban nagyobb aranyban volt kepviselve, s nem egyszer dominanciajuk is megfigyelhető volt. A lapok algaflorajanak bemutatasakor a szerzők altalaban a Desmidiales flora gazdagsagat es kulonlegessegeit szoktak kiemelni, mi azonban ugy veljuk, hogy a lapokat az igen jellegzetes, es a mas vizi előhelyeketől markansan elterő dinoflagellata floraval is jellemezhetjuk.
G. Hajós proved that if a finite abelian group is a direct product of its cyclic subsets, then at... more G. Hajós proved that if a finite abelian group is a direct product of its cyclic subsets, then at least one of the factors must be a subgroup. We give a new elementary proof of this theorem based on the special case for p-groups.
Consider the set of closed unit cubes whose edges are parallel to the coordinate unit vectors e,,... more Consider the set of closed unit cubes whose edges are parallel to the coordinate unit vectors e,,...,e" and whose centers are re., 0<|;|*i, in ndimensional Euclidean space. The union of these cubes is called a cross. This cross consists of 2kn + 1 cubes; a central cube together with In arms of length k. A family of translates of a cross whose union is «-dimensional Euclidean space and whose interiors are disjoint is a tiling. Denote the set of translation vectors by L If the vector set L is a vector lattice, then we say that the tiling is a lattice tiling. If every vector of L has rational coordinates, then we say that the tiling is a rational tiling, and, similarly, if every vector of L has integer coordinates, then we say that the tiling is an integer tiling. Is there a noninteger tiling by crosses? In this paper we shall prove that if there is an integer lattice tiling by crosses, if 2kn + 1 is not a prime, and if p > k for every prime divisor p of 2 kn + I, then there is a rational noninteger lattice tiling by crosses and there is an integer nonlattice tiling by crosses. We will illustrate this in the case of a cross with arms of length 2 in 55-dimensional Euclidean space. Throughout, the techniques are algebraic.
... K. Hale Georgia Institute of Technology S. Kobayashi University of California, Berkeley Marvi... more ... K. Hale Georgia Institute of Technology S. Kobayashi University of California, Berkeley Marvin Marcus University of California, Santa Barbara WS Massey ... Differential Equations and Applications VII L. Sabinin, et al., Non-Associative Algebra and Its Application KM Furati, et al ...
In 1961 J. Stein proposed an algorithm to compute the greatest common divisor of two integers. In... more In 1961 J. Stein proposed an algorithm to compute the greatest common divisor of two integers. In this paper we point out that similar algorithms exist in the ring of integers of various quadratic number fields and also in the non-commutative ring of the Hurwitz quaternions. The implementations of the algorithms are straightforward. However the procedures vary from case to case.
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Papers by Sándor Szabó