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1
Content available remote 3D Ornamentowane zdefiniowane struktury krzemionkowe otrzymane przez okrzemki
PL
Zaprezentowano zwięzłą charakterystykę okrzemek z podaniem możliwości ich aplikacji w różnych gałęziach przemysłu.
EN
A review, with 54 refs., of propertions and methods for prod. of SiO₂ structures under lab. and pilot plant conditions.
EN
In this study, a total of 53 taxa were identified from 13 catchments in Turkey. Gomphonema affine var. rhombicum E.Reichardt, G. angusticephalum E.Reichardt & Lange-Bertalot, G. calcifugum Lange-Bertalot & E.Reichardt, G. elegantissimum E.Reichardt & Lange-Bertalot, G. exilissimum (Grunow) Lange-Bertalot & E.Reichardt, G. graciledictum E.Reichardt, G. italicum var. densistriatum Levkov, Mitic-Kopanja & E.Reichardt, G. linearoides Levkov, G. megolobrebissonii D.A.Chudaev, Kociolek & M.A.Golobova, G. minusculum Krasske, G. minutum f. syriacum Lange-Bertalot & Reichardt, G. reediae Levkov, Mitic-Kopanja & E.Reichardt, G. sarcophagus W.Gregory, G. subcapitatum (Grunow) E.Reichardt & Levkov and Gomphosphenia holmquistii (Foged) Lange-Bertalot were recorded for the first time in Turkey. Of the identified taxa, Didymosphenia geminata (Lyngbye) M.Schmidt, Gomphonema acuminatum Ehrenberg, G. affine Kützing, G. angustatum (Kützing) Rabenhorst, G. augur Ehrenberg, G. micropus Kützing, G. minutum (C.Agardh) C.Agardh, G. olivaceum (Hornemann) Brébisson, G. parvulum (Kützing) Kützing and G. truncatum Ehrenberg are common in the waters. G. angustius E.Reichardt, G. insignaffine Reichardt, G. insigne W.Gregory, G. italicum Kützing, G. laticollum E.Reichardt, G. pumilum var. rigidum E.Reichardt & Lange-Bertalot, G. stonei E.Reichardt, G. supertergestinum E.Reichardt and G. vibrio Ehrenberg have been recently recorded from the Turkish waters. The genus Gomphosphenia in Turkey has so far been represented only by G. grovei (M.Schmidt) Lange-Bertalot.
EN
The present contribution provides a study of calcareous nannofossils and siliceous microfossils from the Sawai Bay Formation on Car Nicobar Island, northern Indian Ocean. Two stratigraphically short sediment intervals near Sawai Bay have been examined. Qualitative and quantitative microfossil analyses show the Sawai Bay ‘A’ Section to be devoid of siliceous microfossils, while 24 well-preserved calcareous nannofossil taxa are identified. The Sawai Bay ‘B’ Section yields 18 calcareous nannofossil, 33 radiolarian and 25 diatom taxa. The calcareous nannofossil index taxa (Ceratolithus armatus Müller, 1974a and C. cristatus Kamptner, 1950) indicate both sections to be from zones NN12 (CN10b) and NN13 (CN10c) of early Pliocene (Zanclean) age. The radiolarian taxa, i.e., Didymocyrtis avita Riedel, 1953, Euchitonia spp., Siphocampe lineata (Ehrenberg) Nigrini, 1977, Stichocorys peregrina Riedel, 1953, Semantis spp. and Stylochlamydium sp. are common in the Sawai Bay ‘B’ Section, which is assigned to Zone RN9. Most of the diatom taxa are represented by rep-resentatives of the genera Actinocyclus Ehrenberg, 1837, Azpeitia Peragallo in Tèmpere and Peragallo, 1912, Coscinodiscus Ehrenberg, 1839a, Grammatophora Ehrenberg, 1841 and Triceratium Ehrenberg, 1839b, with the benthic diatom species Triceratium favus Ehrenberg, 1839b being predominant (~35% of the total diatom count). Siliceous microfossils are also represented by silicoflagellates dominated by Dictyocha spp. and sponge spicules dominated by astrophorids.
EN
A total of 15 Navicula taxa were recorded in epilithic communities occurring in seven rivers of Serbia, all of which are new to the diatom flora of Serbia. The most interesting of them are N. splendicula and N. moskalii. When observing N. splendicula specimens under SEM, we noticed a characteristic silicate tongue in the center of raphe ends, which had not been previously reported in the available literature. The insufficiently researched distribution of N. moskalii and scarce autecological information on the taxon prompted us to provide new details about the species in this study. These findings clearly indicate the need for further comprehensive research that would provide new information on rare taxa.
EN
In water systems, both biologically and chemically synthesized molecules may reduce environmental quality and influence essential ecosystems structure and function. These substances include aldehydes from various sources, also those relates to the activities of primary producers. The focus of the study was vertical distribution of several aliphatic aldehydes and phytoplankton biomass in an urban lake in Poznań (Wielkopolska Lakeland, Poland) under human pressure. Water samples were collected from surface lake to bottom, every 2 m. Plankton was analyzed under inverted and epifluorescence microscopes. The biomass was estimated from microscopic measurements and cell volume of each species. Thirteen aldehydes and acetone were analyzed using gas chromatography with an electron capture detector after derivatization and extraction processes. Aldehydes concentrations varied between 32.7 and 346.2 μg L-1. Formaldehyde, acetaldehyde and propanal were characterized by the highest concentration both at low and high phytoplankton biomass. Phytoplankton biomass included prokaryotic and eukaryotic cells, and ranged between 0.25 and 2.94 mg L-1. Cryptophytes and diatoms were often the most important components of phytoplankton communities, although in some cases the haptophytes and dinophytes comprised a much higher proportion. Total aldehyde concentration was significantly correlated with total phytoplankton biomass (r=0.705, p <0.05), and even higher correlation was observed between acetone and phytoplankton biomass (r=0.917). This indicates phytoplankton as an important source of carbonyl compounds in surface waters. Thus, the knowledge of different aspects of their origin and distribution in the lake is important both in ecological research and in water management.
PL
W systemach wodnych, zarówno biologicznie jak i chemicznie syntetyzowane cząsteczki mogą obniżać jakość środowiska i wpływać istotnie na strukturę i funkcjonowanie ekosystemów. Substancje te obejmują aldehydy pochodzące z różnych źródeł, również te związane z aktywnością producentów pierwotnych. Przedmiotem badań było rozpoznanie pionowego rozmieszczenia kilku aldehydów alifatycznych i biomasy fitoplanktonu w jeziorze miejskim w Poznaniu (Pojezierze Wielkopolskie, Polska) znajdującym się pod presją człowieka. Próbki wody pobierano od powierzchni jeziora do dna, co 2 m. Plankton analizowano pod mikroskopem odwróconym i epifluorescencyjnym. Biomasę oszacowano na podstawie pomiarów mikroskopowych i objętości komórek każdego gatunku. Trzynaście aldehydów i aceton analizowano za pomocą chromatografii gazowej z detektorem wychwytującym elektrony po procesach derywatyzacji i ekstrakcji. Stężenia aldehydów wahały się od 32,7 do 346,2 μg L-1. Formaldehyd, aldehyd octowy i propanal charakteryzowały się największym stężeniem zarówno przy niskiej, jak i wysokiej biomasie fitoplanktonu. Biomasa fitoplanktonu obejmowała komórki prokariotyczne i eukariotyczne i mieściła się w przedziale od 0,25 do 2,94 mg L-1. Kryptofity i okrzemki były często najważniejszymi składnikami zbiorowisk fitoplanktonu, choć w niektórych przypadkach większy udział miały haptofity i dinofity. Ogólne stężenie aldehydów było istotnie skorelowane z całkowitą biomasą fitoplanktonu (r=0,705, p <0,05), przy czym jeszcze silniejszą korelację zaobserwowano między acetonem i biomasą fitoplanktonu (r=0,917). Wskazuje to na fitoplankton jako ważne źródło związków karbonylowych w wodach powierzchniowych. Tym samym wiedza o różnych aspektach ich pochodzenia i rozmieszczenia w jeziorze jest ważna zarówno podczas badań ekologicznych, jak i w gospodarce wodnej.
EN
Madagascar is an isolated island characterized by a high degree of endemism at all taxonomic levels. Diatom assemblages of the region are still poorly known and sporadic sampling events in various habitats (e.g. lagoons, mangroves) have revealed a large number of taxa that could not be identified. This study presents detailed descriptions of two new species of Luticola: L. nosybeana and L. madagascarensis, collected from mangrove roots on Nosy Be Island. Comparisons with the described congeners showed that the density of striae in Luticola nosybeana is higher than that in L. belawanensis and proximal raphe endings terminate as irregular, shallow grooves. Luticola madagascarensis differs from L. similis in the shape of proximal raphe endings, which are short and expanded in the latter, while continue with irregular, shallow, elongated L-shaped grooves in L. madagascarensis. Luticola nosybeana and L. madagascarensis can be distinguished under a light microscope by the shape of the central area (bow-tie shaped in L. madagascarensis and deltoid in L. nosybeana) and isolated pores (robust and well visible in L. madagascarensis, poorly discernible in L. nosybeana). The two new species are unique in their habitat preferences: while all known congeners are freshwater, the new species inhabit estuarine mangroves.
EN
The main objective of this paper is to report two diatoms (Caloneis africana (Giffen) Stidolph and Luticola nivalis (Ehrenberg) D. G. Mann) from Cochin backwaters, which prove to be a new finding from Indian waters. Surface water samples were collected monthly from twelve stations covering the ecosystem from May 2015 to April 2016. The analysis of physicochemical parameters and the preparation of permanent slides of diatoms were performed based on standard procedures. Descriptions, world distribution and photographs of the two diatoms are included in this paper. These two new species further enrich the diatom floristic diversity of Cochin backwaters in India.
EN
During the study on the assessment of ecological status of the Lepenci river basin, epilithic diatoms were used. Via this methodology, the authors aimed to standardization the ecological assessment methodology and gradually make it applicable for all river basins of Kosovo. The authors relied on a hypothesis that the epilithic diatom communities can serve as a reliable ecological tool to evaluate the quality of flowing waters in Kosovo. Thirteen water quality indices (IBD, IPS, IDG, DESCY, SLA, IDSE, IDAP, EPID, CEE, WAT, TDI, IDP and SHE) were measured in eight sample-points. From the conducted qualitative analysis, the obtained results showed that the water quality varies from upper parts of the basin (SP1, SP2, SP3 & SP4) characterized with higher water quality towards the lower parts (SP5, SP6 & SP7) where water quality was of the 2nd class and finally in Hani i Elezit (SP8) where the index values showed that its water belongs to the 3rd class. The samples were taken in to 8 sampling sites, in river during year (2017), the Navicula viridula species was the most dominant, along with Cocconeis placentula var. lineate and Diatoma vulgaris. In turn, between August and end of September, the following species were dominant ones: Craticula ambigua, Navicula hintzii, Navicula viridula and Rhoicosphenia abbreviata.
EN
A sediment core, 350 cm long recovered from Młynek Lake, northern of Poland (Warmia and Masuria Region) was analyzed with respect to their content of diatoms and chrysophyte cysts. The aim was to reconstruct the lake water level and climatic changes during the past 2500 years. The recognized diatom assemblages displayed marked floristic changes along the sediment core samples. The main change in diatom composition consists of a shift from an assemblage dominated by benthic Fragilaria sensu lato species through marked intervals to a planktonic one in distinct zones. A high proportion of benthic to plankton taxa has been reported as indicative for a lowering of the lake level with long ice cover in a cold dry climate and a shift from benthic to planktonic diatom taxa reflects arising water level with longest growing season and reduced ice cover on the lake during a warm wet climate. Multivariate statistical analysis included hierarchical ascending clustering distinguished four diatom ecological groups. The analyzed core section was divided into 11 diatom zones according to a distribution of ecological groups and variation in abundance of dominant species supported by 14C data. The results displayed a developmental history of the Młynek Lake that can be divided into 6 main phases of alternating warm wet and cold dry shifts. A distinct dominance of planktonic eutrophic indicator diatoms accompanied by a low abundance of chrysophyte cysts indicates increased lake trophicity and a general trend for the increasing anthropogenic impact.
EN
This study focused on phytoplankton changes in polluted waters of Lake Manzala and the assessment of heavy metal bioaccumulation capacity during the 15-day laboratory experiment. Phytoplankton samples were analyzed every day and the concentration of zinc, iron and lead in water, in phytoplankton and in filtrate – every fifth day of the experiment. Significantly higher phytoplankton abundance was recorded in water from the El-Boom station (basin I) compared to the New Bahr El-Baqar drain (basin II), followed by distinct differences in its composition and chlorophyll content. However, the most abundant species were the same in both basins, i.e. Chroococcus minor, Microcystis aeruginosa, Actinoptychus octonarius, Aulacoseira granulata, Pantocsekiella ocellata, Kirchneriella obesa and Nephrocytium limneticum. Water in basin I was more polluted with heavy metals compared to basin II. Basin I was characterized by the dominance of cyanobacteria and high relative abundance of chlorophytes compared to basin II, where either cyanobacteria and/or diatoms dominated in the phytoplankton. In the former basin, the highest uptake factors (UFs) were recorded for iron and zinc and the lowest UF for lead. In basin II, the highest UF was determined for zinc, but relatively high UFs were recorded also for iron and lead. The presented results suggest that phytoplankton can contribute to natural biosorbents of heavy metals in Egyptian lakes.
EN
The aim of this work was to present a morphological description and ecological characteristics of a rare species from the Gomphonema genus, occurring in calcium-rich waters, along with its new occurrence sites. The research was carried out in flowing waters of mountain and sub-mountain streams and rivers in Poland: the Wołosaty, the Wisłoka, the San and their tributaries. The occurrence of many rare and new to Polish flora species from the genus Gomphonema was recorded: G. cuneolus E. Reichardt, G. drutelingense E. Reichardt, G. innocens E. Reichardt,G. lateripunctatum E. Reichardt & Lange-Bertalot, G. lippertii E. Reichardt & Lange-Bertalot and G. calcifugum Lange-Bertalot & E. Reichardt. These species occur mostly in alkaline or close-to-neutral waters with medium or low electrolytic conductivity (78–530 μS cm-1), low nutrient content and medium-to-high calcium ion content (12.4–76.4 mg l-1). Despite the rare occurrence in other parts of the world, the studied Gomphonema species has found favorable conditions in unpolluted and calcium-rich stream beds with flysch strata. The literature data define G. calcifugum as a non-calciphilous species, but this study shows that it can develop in a wide pH range and in calcium-rich waters.
EN
This study describes the subfossil diatom flora in the surface sediments of the Polish coastal waters in relation to human impact. The material studied consists of the uppermost parts of seven sediment cores collected from the SW Gulf of Gdańsk and eight cores from the Vistula Lagoon. Our results show the present-day ecological state of both basins just before the planned construction of a navigable channel of the Vistula Spit, which will be the next factor affecting their hydrology. In different parts of the Gulf of Gdańsk, cultural eutrophication resulted in a distinct “anthropogenic assemblage” in the surface sediments. Its structure relates directly to the distance from the mouth of the Vistula River. In the surface assemblages of the Vistula Lagoon, the number of salt-tolerant diatoms increased with the salinity of the basin. Locally, a large number of pollution-resistant taxa was also observed.
EN
Contemporary assessment of the ecological status of aquatic ecosystems is based on various groups of organisms, including diatoms. Biological assessment, implemented by the Water Framework Directive, has been applied worldwide for more than 15 years. Currently, the most basic “tool” used in biomonitoring are diatom indices, which are routinely applied in Europe and other countries around the world. In Poland, the diatom indices have been used for over 5 years, which is a period of time allowing to summarize and evaluate the effectiveness of these methods in the assessment of aquatic ecosystems. The purpose of this work was to analyse the use of diatom indices in the biomonitoring of surface water by collecting data on the possibilities and limitations of using diatom indices for the objective assessment of water quality. Attention was paid to mistakes made in the course of biological assessment performed with the use of diatom phytobenthos, which have a significant impact on the obtained results. The paper also contains suggestions for introducing several important changes in biological monitoring, which will improve its quality and efficiency in assessing the ecological status of various aquatic ecosystems.
EN
An autochthonous community of benthic diatoms was discovered in June 2015 in the upper sediment layer at depths of 170, 205, and 245 m in the central Barents Sea. At least three benthic microalgae species (Gyrosigma fasciola, Pleurosigma angulatum, and Pleurosigma sp. 1) were detected in the sediment but not the upper water column. Analyses revealed that these benthic microalgae represent a depleted fragment of Arctic littoral microphytobenthos. Compared with the littoral flora, the deep-water assemblage is less diverse and displays low abundance. The data reported here challenge the generally accepted belief that the presence of certain microalgae at significant depths results from vertical or horizontal transfer.
EN
The study was conducted in an old, historical park, in the northern part of Stalowa Wola city (south-eastern Poland). The aim of the study was to investigate the diversity of moss-inhabiting diatoms of the white poplar (Populus alba L.) bark. During the study, a total of 47 diatom taxa were found, three out of which were considered as dominant. Three other species are mentioned in the Red List of the Algae in Poland: Achnanthes coarctata (Brébisson) Grunow, Luticola acidoclinata Lange-Bertalot and Stauroneis thermicola (Petersen) Lund. For three species: Luticola sparsipunctata Levkov, Metzeltin & Pavlov, L. vanheurckii Van de Vijver & Levkov and Hantzschia subrupestris Lange-Bertalot, this is the first report from Poland.
EN
The paper reports properties of the resin matrix with frustules of diatoms Didymosphenia geminata. The samples of resin containing up to 70% of the volume fraction of the frustules have been prepared in a relatively simple procedure for a commercial resin and using the frustules “harvested” in one of the rivers in Poland by a manual mixing. The compression tests of the samples proved the strengthening effect of the frustules, with the apparent compression modulus increasing by 100% for the volume fraction of 60%. The results of this investigation indicate a high potential of D. geminata frustules in composite technology.
PL
Didymosphenia geminata to słodkowodna okrzemka charakteryzująca się krzemionkowym pancerzykiem i stylikiem wytworzonym z zewnątrzkomórkowego materiału polimerowego. Wymiary pojedynczego pancerzyka D. geminata, wynoszą 80÷140 μm długości i 35÷45 μm szerokości, co sprawia, że jest jedną z większych okrzemek. Zgodnie z trendem stosowania materiałów biologicznych i biomimicznych w pracy przyjęto założenie, że pancerzyki okrzemek mogą być potencjalnie zastosowane jako faza zbrojąca w materiałach kompozytowych o osnowie polimerowej. Jednym z najczęściej stosowanych materiałów na osnowę w kompozytach polimerowych jest żywica epoksydowa. Żywica tego typu jest zbrojona proszkami. Celem niniejszej pracy było zbadanie wykorzystania w tej roli pancerzyków okrzemki Didymosphenia geminata. Podjęte badania polegały na wytworzeniu serii próbek materiałów kompozytowych na osnowie z żywicy epoksydowej z różnym udziałem objętościowym napełniacza. Otrzymane próbki scharakteryzowano pod kątem ich struktury i właściwości mechanicznych.
EN
This study evaluates changes in the environmental and climatic conditions in the Faiyum Oasis during the Holocene based on diatom analyses of the sediment FA-1 core from the southern seashore of the Qarun Lake. The studied FA-1 core was 26 m long and covered the time span ca. 9.000 cal. yrs BP. Diatom taxa were abundant and moderately to well-preserved throughout the core sediments. Planktonic taxa were most abundant than the benthic and epiphytic forms, which were very rare and sparsely distributed. The most dominant planktonic genera were Aulacoseira and Stephanodiscus followed by frequently distribution of Cyclostephanos and Cyclotella species. The stratigraphic distribution patterns of the recorded diatoms through the Holocene sediments explained five ecological diatom groups. Thesegroups represent distinctive environmental conditions, which were mainly related to climatic changes through the earlyand middle Holocene, in addition to anthropogenic activity during the late Holocene. Comparison of diatom assemblages in the studied sediment core suggests that considerable changes occurred in water level as well as salinity. There were several high stands of the freshwater lake level during humid, warmer-wet climatic phases marked by dominance of planktonic, oligohalobous and alkaliphilous diatoms alternated with lowering of the lake level and slight increases in salinity and alkalinity during warm arid conditions evident by prevalence of brackish water diatoms.
EN
We investigated diatom assemblages in surface sediments of 46 lakes in northern Poland and developed a diatom-based transfer function to infer epilimnetic total phosphorus (TP) concentrations. Multivariate ordination techniques (DCA, CCA) were used to identify major environmental gradients and to evaluate the effect of environmental parameters on the distribution of diatoms in the modern diatom dataset. The transfer function was developed using PLS, WA and WA-PLS models, and applied to a varved sediment core from Lake Żabińskie, AD 1888-2010. Annually-resolved quantitative reconstruction of TP concentrations shows that multidecadal changes in the TP level reflect the local settlement history, land-use changes and development of agriculture and tourism. The period of high trophic levels with maximum values of TP was documented until the late 1920s. In the 1930s-1970s period, TP generally decreased and eutraphentic flora was partly replaced by oligotraphentic and oligo-mesotraphentic diatom taxa. The reconstructed TP concentrations have started to increase from the 1970s. After the 1950s, strong short-term fluctuations of TP values were noted and explained by interactions between meteorological conditions, water column mixing and nutrient cycling in the lake.
EN
Phytoplankton samples collected from the Northern Indian Ocean (Bay of Bengal, northern Arabian Sea, and Dona Paula Bay Goa, west coast of India), were utilized to quantify changes in cell size, cell volume and carbon per cell of diatoms and dinoflagellates. The dataset from the Bay of Bengal also provides inter- and intra-annual variations (April 2008 to March 2010). The variations in cell size and volume were large in regions influenced by the riverine influx or terrigenous inputs. An interregional comparison of commonly available forms (8 species) points out that cell volumes are highest in the North Atlantic and lowest in the Mediterranean. The information provided will be useful in estimation of carbon biomass and biogeochemical studies.
EN
The aim of the research was to investigate the soil properties and the species diversity of diatoms growing in different agricultural fields with silt loamy soil. The field experiment was conducted in 2014 in Kosina, near Łańcut (SE Poland), at three sites (indicated as fields K1, K2, K3) with different soil environmental conditions and plants. The growth of winter wheat Triticum aestivum (cv. Bogatka) in fields K1 and K2 and oats Avena Sativa (cv. Haker) in field K3 under different soil management were studied. The soil samples were collected from the top layers (0–5 cm depth) each month, from April to December. Certain physical and chemical parameters of soil were measured. The pH of soil was acidic and slightly acidic in fields K1 (5.0–5.4), K2 (4.9–5.9) and K3 (4.5–5.1). The soil in field K3 had a significantly greater content of organic matter (1.06–1.30%) and water content (12.9–33.8%, v/v) than fields K1 and K2. A total of 91 diatom taxa were found. The diversity was greatest in field K2 (71 taxa), lower in K1 (54 taxa) and K3 (24 taxa). In K1, the most numerous species were Luticola D.G. Mann cf. mutica, Mayamaea atomus var. permitis (Hust.) Lange-Bertalot, and Stauroneis thermicola (Petersen) Lund, with more than a 20% share in the assemblage. In K2, very abundant assemblages were formed by Mayamaea atomus (Kütz.) Lange Bertalot, Mayamaea atomus var. permitis (Hust.) Lange-Bertalot, and Stauroneis thermicola (Petersen) Lund with a 25 to 50% share in the total diatom community. In K3, with oat cultivation, a different diatom species structure was found. Here, the most abundant were Halamphora montana (Krasske) Levkov, Hantzchia amphioxys (Ehrenb.) Grunow, Mayamaea atomus (Kütz.) Lange-Bertalot, and Nitzschia pusilla Grunow, which attained a share in the assemblage exceeding than 20%. The effects of different soil management regimes under different plants on the physical and chemical properties of the soil, and on the diversity of diatoms, were significant (P<0.05). Soil water and organic matter content affects the yield of winter wheat and oats. Significant effects of water content and pH of silt loamy soil on the growth and the diversity of species of diatoms were found.
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