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Search Results: 1 - 10 of 141051 matches for " Stanis?aw K?osowski "
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Temporal and spatial variation of habitat conditions in the zonation of vegetation in the late stages of lake overgrowth
Stanisaw Kosowski
Acta Societatis Botanicorum Poloniae , 2002, DOI: 10.5586/asbp.2002.039
Abstract: The water and substrate properties in the vegetation zones characteristic of the late stages of lake overgrowth were determined. It was demonstrated that the spatial distribution of plant communities conformed with the spatial gradient of habitat conditions. With regard to water properties the largest differences between the zones were found in Mg2+, Ca2+, electrolytic conductivity and NH4+. In the case of substrate the zones differed significantly in Ca2+, total Fe and organic matter content. The water properties varied greatly during the vegetative season in the successive zones. The temporal changes often proceeded at a different level of a given component or factor in most zones. The differences between the zones were, however, maintained. It appears that the plant communities can alter their habitats to a large extent. In the lake studied, the invasion of raised and transitional bog vegetation was observed. The process of dystrophy proceeded from the terrestrialized peripheral parts of the lake to the centre of the lake.
Habitat differentiation of the Myriophyllum altemiflorum and Littorella uniflora phytocoenoses in Poland
Stanisaw Kosowski,Marcin Szańkowski
Acta Societatis Botanicorum Poloniae , 2004, DOI: 10.5586/asbp.2004.013
Abstract: The present study showed the ecological differentiation of phytocoenoses dominated either by Myriophyllum alterniflorum or by Littorella uniflora, which in Poland are classified within the Myriophylletum alterniflori or Myriophyllo-Littorelletum association. The properties which best differentiated the waters of the above types of phytocoenoses were calcium and factors associated with the carbonate complex (pH, electrolytic conductivity, total and carbonate hardness), and pH in the case of substrates. The most distinct differences in the habitats were found between the phytocoenoses dominated by L. uniflora from the Pomeranian Lobelia lakes and those dominated by M. alterniflorum from the czna-W odawa Lake District, in which other species from the Littorelletea uniflorae class were absent. The L. uniflora phytocoenoses are associated with soft waters poor in Ca2+ and with the lowest values of pH, electrolytic conductivity, dissolved organic matter (COD-KMnO4) and dissolved SiO2. The substrates they inhabit are mineral and more acidic. By contrast, the values of the above-mentioned properties are considerably higher in the case of the phytocoenoses from the czna-W odawa Lake District. The habitats of the M. alterniflorum phytocoenoses from the Pomeranian Lobelia lakes occupy an intermediate position and are more similar to those of M. alterniflorum from the czna-W odawa Lake District. The results obtained in this study suggest that the phytocoenoses of L. uniflora and M. alterniflorum should not be included in the same association. Further studies are, therefore, necessary to resolve this problem. The comparative analysis of the present ecological findings and data obtained from other regions of Europe show that in Poland the phytocoenoses dominated either by L. uniflora or by M. alterniflorum, in which the contribution of Littorelletea uniflorae species is appreciable, are clearly associated with soft waters and their habitats are representative of the Littorelletea uniflorae class. The massive development of the phytocoenoses with both L. uniflora and M. alterniflorum in the Lobelia lakes is not always indicative of the increase in water hardness and euthrophication of waters typical of the communities of the Littorelletea uniflorae class. The M. alterniflorum dominated phytocoenoses without other Littorelletea species could be good indicators of the above processes taking place in such water ecosystems.
Distribution and habitat conditions of the phytocoenoses of Sphagnum denticulatum Bridel and Warnstorfia exannulata (B., S. and G.) Loeske in Polish Lobelia lakes
Marcin Szańkowski,Stanisaw Kosowski
Acta Societatis Botanicorum Poloniae , 2004, DOI: 10.5586/asbp.2004.033
Abstract: Phytosociological and habitat studies of Sphagnum denticulatum and Warnstorfia exannulata phytocoenoses from Polish Lobelia lakes have been conducted. The present results were compared with data on Isoetes lacustris community. It is demonstrated that both communities of mosses are distinct with respect to their floristic composition. Moreover, they differ significantly from the patches of I. lacustris with regard to many properties of water and substrates. The phytocoenoses of S. denticulatum are associated with softer waters, poorer in Ca2+, Na+, NH4+ and dissolved organic matter, but richer in total Fe than those of I. lacustris. They are also distinguished by lower values of electrolytic conductivity. The substrates they inhabit are more strongly hydrated and richer in organic matter, total N, dissolved SiO2, Ca2+ and Na+, but poorer in PO43-. The W. exannulata phytocoenoses are also confined to softer waters with lower Ca2+, NH4+ and dissolved organic matter contents than those of I. lacustris. Their substrates are more strongly hydrated and have higher contents of organic matter, total N and Na+ but lower amounts of PO43-. In addition the waters of W. exannulata phytocoenoses are characterized by higher pH values and lower concentration of dissolved SiO2. The substrates are less acidic and richer in NO3-, but poorer in total Fe. The differences between the habitats of the S. denticulatum and W. exannulata phytocoenoses are also distinct. The former inhabit more acidic waters, richer in dissolved SiO2 and total Fe, but with lower values of electrolytic conductivity and concentration of Na+. Their substrates are distinguished by higher contents of organic matter and Ca2+, as well as by lower amount of NO3-. In view of the fact that the above phytocoenoses of mosses are distinct with respect to their floristic composition and are associated with specific habitats in which they form dense mats close to the bottom of the lake, they should be classified as distinct associations (Sphagnetum denticulati and Warnstorfietum exannulatae) in the system of aquatic communities (Class: Utricularietea intermedio-minoris).
Habitat conditions of the Nymphaeetum candidae Miljan 1958 and Nupharo-Nymphaeetum albae Tomaszewicz 1977 dominated by Nymphaea alba
Stanisaw Kosowski,Henryk Tomaszewicz
Acta Societatis Botanicorum Poloniae , 1989, DOI: 10.5586/asbp.1989.048
Abstract: The paper presents comparative analysis of habitats of 19 phytocoenoses of the Nymphaeetum candidae and 21 phytocoenoses of the Nupharo-Nymphaeetum albae dominated by N. alba from the lakes of north-eastern Poland. The differences in ecological amplitudes and optima of occurence between two phytocoenose types were pronounced. The N. candida phytocoenoses had narrower amplitudes both regarding the properties of water and substrate and required higher minimum nutrient contents as compared to the N. alba phytocoenoses. Habitat distinction of phytocoenoses dominated by N. candida expressed in a relatively narrow trophic amplitude totally justifies to distinguish Nymphaeetum candidae as a separate syntaxon.
Ecology of rare water plant communities in lakes of north-eastern Poland
Ewa Jab?ońska,Stanisaw Kosowski
Acta Societatis Botanicorum Poloniae , 2012, DOI: 10.5586/asbp.2012.006
Abstract: Habitat studies were conducted on three rare plant communities dominated by Nuphar pumila, Nymphaea candida and Hydrilla verticillata in lakes of north-eastern Poland. The comparison of habitat properties of these three types of phytocoenoses with those of Nuphar lutea common in the area under study was also performed. It was demonstrated that the plant communities studied were ecologically distinct. The habitats of the phytocoenoses of N. pumila differed most significantly from those of the other phytocoenoses. They often inhabited softer waters poor in Mg2+, dissolved SiO2, but rich in total Fe, PO43 , NO3 , and were associated with acidic substrates containing lower levels of Ca2+ and Na+, but greater amounts of total Fe and NO3 . The differences in the habitats of H. verticillata and N. candida phytocoenoses were most pronounced in the case of four properties of water: Na+, K+, Cl , and Mg+. Their values were lower in waters of the H. verticillata phytocoenoses. The habitats of all the three types of rare phytocoenoses differed considerably from those of N. lutea. The most significant differences were found between the N. lutea and N. pumila phytocoenoses and the smallest differences were between the patches of N. lutea and N. candida. The properties of water were more important in differentiating the habitats of the phytocoenoses studied than the substrate properties. Due to alkalization and increase in water hardness in the lakes studied the stands of N. pumila are among the most threatened. The patches of N. candida and H. verticillata, which occur in waters with a wider range of hardness and tolerating a slight increase in trophy, can still continue to persist in the lakes for a long time.
Aneuploids in the shrub birch Betula humilis populations in Poland
Katarzyna A. Jadwiszczak,Ewa Jab?ońska,Stanisaw Kosowski,Agata Banaszek
Acta Societatis Botanicorum Poloniae , 2011, DOI: 10.5586/asbp.2011.015
Abstract: Shrub birch (Betula humilis Schrk.) is endangered glacial relict growing in natural and drained fens and transitional mires. At present study we examined karyotypes of 103 individuals of B. humilis, collected in six populations from eastern and northeastern Poland. We found 60% of diploid individuals with 2n = 28. The rest of studied plants were aneuploids with 26, 27, 29, 30 and 31 chromosomes in their karyotypes. High frequencies of aneuploids in Polish populations of B. humilis could be a consequence of: (i) hybridization with congeneric species, (ii) stress resulting from range fragmentation, (iii) karyotype instability of individuals with 2n ≠ 28, or (iv) vegetative reproduction.
New automated image analysis method for the assessment of Ki-67 labeling index in meningiomas.
Bart?omiej Grala,Tomasz Markiewicz,Wojciech Koz?owski,Stanisaw Osowski
Folia Histochemica et Cytobiologica , 2010, DOI: 10.5603/4304
Abstract: Many studies have emphasised the importance of Ki-67 labeling index (LI) as the proliferation marker in meningiomas. Several authors confirmed, that Ki-67 LI has prognostic significance and correlates with likelihood of tumour recurrences. These observations were widely accepted by pathologists, but up till now no standard method for Ki-67 LI assessment was developed and introduced for the diagnostic pathology. In this paper we present a new computerised system for automated Ki-67 LI estimation in meningiomas as an aid for histological grading of meningiomas and potential standard method of Ki-67 LI assessment. We also discuss the concordance of Ki-67 LI results obtained by presented computerized system and expert pathologist, as well as possible pitfalls and mistakes in automated counting of immunopositive or negative cells. For the quantitative evaluation of digital images of meningiomas the designed software uses an algorithm based on mathematical description of cell morphology. This solution acts together with the Support Vector Machine (SVM) used in the classification mode for the recognition of immunoreactivity of cells. The applied sequential thresholding simulated well the human process of cell recognition. The same digital images of randomly selected tumour areas were parallelly analysed by computer and blindly by two expert pathologists. Ki-67 labeling indices were estimated and the results compared. The mean relative discrepancy between the levels of Ki-67 LI by our system and by the human expert did not exceed 14% in all investigated cases. These preliminary results suggest that the designed software could be an useful tool supporting the diagnostic digital pathology. However, more extended studies are needed for approval of this suggestion.
Magnetic Field Induction and Time Intervals of the Electron Transitions Approached in a Classical and Quantum-Mechanical Way  [PDF]
Stanisaw Olszewski
Journal of Modern Physics (JMP) , 2011, DOI: 10.4236/jmp.2011.211161
Abstract: The motion of electron wave packets of a metal is examined classically in the presence of the magnetic field with the aim to calculate the time intervals between two states lying on the same Fermi surface. A lower limiting value of the transition time equal to about 10–18 sec is estimated as an average for the case when the states are lying on the Fermi surface having a spherical shape. Simultaneously, an upper limit for the electron circular frequency in a metal has been also derived. A formal reference of the classical transition time to the time interval entering the energy-time uncertainty relations known in quantum mechanics is obtained.
Relation between the Intervals ΔE and Δt Obtained in the De-Excitation Process of Electrons in Metals  [PDF]
Stanisaw Olszewski
Journal of Modern Physics (JMP) , 2012, DOI: 10.4236/jmp.2012.33030
Abstract: A relation between the intervals of energy and time, derived in a former paper and associated with the electron transitions on the Fermi surface of a metal, is examined in comparison with the experimental data. These data are obtained from the de-excitation process of electrons in metals. A comparison between theory and experiment demonstrated that the new relation between energy and time is fitted much better for the experimental results than the well-known relation due to the Heisenberg theory.
Quantum of the Magnetic Flux Characteristic forExperiments Performed on the Integer and Fractional Quantum Hall Effects  [PDF]
Stanisaw Olszewski
Journal of Modern Physics (JMP) , 2013, DOI: 10.4236/jmp.2013.411A1003
Abstract:

Experimentally the plateaus characteristic for the integer quantum Hall effect is obtained in vicinity of specific values of the magnetic induction. The paper demonstrates that the ratios of these induction values to carrier concentration in the planar crystalline samples approach systematically the quanta of the magnetic flux important for the behavior of superconductors. Moreover, the same quanta can be deduced from the Landau levels theory and their application in the magnetoresistance theory gives results being in accordance with experiments. The quanta of the magnetic flux similar to those for the integer quantum Hall effect can be obtained also for the fractional quantum Hall effect. This holds on condition the experimental ratio of the magnetic flux to carrier concentration is multiplied by the filling factor of the Landau level.

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