79 research outputs found
Red tides of the dinoflagellate Noctiluca scintillans associated with eutrophication in the Sea of Marmara (the Dardanelles, Turkey)
No full textThis investigation focused on weekly variations in cell density and volume of the dinoflagellateNoctiluca scintillans between March 2001 and January 2004 in the Dardanelles. March-June andOctober-December periods were excessive bloom periods. During the bloomperiods the density of N. scintillans reached 2.20 × 105 cells L-1 witha volume of 1.32 × 1012 µm3 L-1. In addition tothe high surface density, there was an increase in subsurface waters duringthe blooms. The bloom of N. scintillans, like that of diatom and otherdinoflagellate blooms, was associated not only with eutrophication, but alsowith stable temperatures and salinities
and three dinoflagellates in the Dardanelles (Turkish Straits System)
No full textThis study focuses on the synchronous blooms of the coccolithophore Emiliania huxleyi and three dinoflagellates Prorocentrum micans, Ceratium furca Par. furca and Cerathum fusus var. seta observed between 7 June and 11 July 2003 in the Dardanelles. An analysis of the vertical distribution of the E. huxleyi population size with respect to various environmental parameters was discussed. Additionally, inorganic nutrients and phytoplankton interactions were investigated in relation to the bloom conditions and hydrography of the Dardanelles, The algal bloom started in nearby Izmit Bay (eastern end of the Sea of Marmara) in early June, then quickly spread through the Sea of Marmara and continued until mid-July. Thermal stratification was observed between different water masses at the time of sampling. During the bloom period, cell density of F. huxleyi ranged from 3.58 x 10(7) to 2.55 x 10(8) cells l(-1) in the superficial layer. Prorocentrum micans was the second most-abundant species and the cell numbers ranged from 1.0 x 10(6) cells l(-1) to 3.3 x 10(6) cells l(-1). Other abundant species in this area included C. furca var. furca and C. fusus Par. seta
Novel Hybrid Scaffolds for the Cultivation of Osteoblast Cells
No full textTurkoglu Sasmazel, Hilal/0000-0002-0254-4541In this study, natural biodegradable polysaccharide, chitosan, and synthetic biodegradable polymer, poly(epsilon-caprolactone) (PCL) were used to prepare 3D, hybrid polymeric tissue scaffolds (PCL/chitosan blend and PCL/chitosan/PCL layer by layer scaffolds) by using the electrospinning technique. The hybrid scaffolds were developed through HA addition to accelerate osteoblast cell growth. Characteristic examinations of the scaffolds were performed by micrometer, SEM, contact angle measurement system, ATR-FTIR, tensile machine and swelling experiments. The thickness of all electrospun scaffolds was determined in the range of 0.010 +/- 0.001-0.012 +/- 0.002 mm. In order to optimize electrospinning processes, suitable bead-free and uniform scaffolds were selected by using SEM images. Blending of PCL with chitosan resulted in better hydrophilicity for the PCL/chitosan scaffolds. The characteristic peaks of PCL and chitosan in the blend and layer by layer nanofibers were observed. The PCL/chitosan/PCL layer by layer structure had higher elastic modulus and tensile strength values than both individual PCL and chitosan structures. The layer by layer scaffolds exhibited the PBS absorption values of 184.2; 197.2% which were higher than those of PCL scaffolds but lower than those of PCL/chitosan blend scaffolds. SaOs-2 osteosarcoma cell culture studies showed that the highest ALP activities belonged to novel PCL/chitosan/PCL layer by layer scaffolds meaning better cell differentiation on the surfaces. (C) 2011 Elsevier B.V. All rights reserved.Turkish Academy of Science (TUBA) L'Oreal; L'OrealThe author is greatly thankful to Turkish Academy of Science (TUBA) & L'Oreal for honoring this study with the award "Young Women in Science" in Materials Science in 2009. Her special thanks also go to L'Oreal for the precious financial support. The author also appreciates the invaluable contribution of AWAC (Academic Writing Advisory Center) to this study in linguistic terms
Çanakkale Bo?azı (Türk Bo?azlar Sistemi) yüzey sularında fitoplankton, besin tuzları ve klorofil a da meydana gelen zamansal de?işimler: Haftalık zaman aralı?ında bir kıyısal istasyon örne?i
No full textIn this study, weekly distributions of inorganic nutrients and phytoplankton cell volumes were investigated in relation to the hydrology of the Dardanelles. The data were collected between March 2001 and March 2002. NO2-+NO3-, PO4-3, and SiO4 concentrations ranged between 0.050-6.887 mu M, 0.051-1.152 mu M, and 0.64-10.74 mu M, respectively. During the study, the highest nutrient values were measured between late fall and mid-winter. Inorganic N:P and Si:P ratios in the surface water were lower due to high PO4-3 concentrations. The chlorophyll a concentrations ranged from 0.03 to 8.67 mu g L-1. Phytoplankton cell density and cell volume ranged from 1.54E + 05 to 6.46E + 07 cell L-1 (mean 7.65E + 06; SD 1.44E + 07 cell L-1) and from 2.51E + 09 to 8.66E + 10 mu m(-3) L-1 (mean 1.98E + 10; SD 1.86E + 10 mu m(-3) L-1) between less productive and high productive periods. During the study period, 8-10 species controlled the phytoplankton community structure in the coastal zone of the Dardanelles. Others did not contribute to the phytoplankton population and they only can be considered as accessory species, which do not cause significant fluctuations in the phytoplankton production. Relationships between chlorophyll a, cell density, and cell volume of phytoplankton revealed that chlorophyll a is rather controlled by the cell density than by the cell volume. Furthermore, the physicochemical variables, such as nutrients and chlorophyll a and phytoplankton cell density and cell volume, are affected by the counter flows in the Dardanelles. Phytoplankton population was more limited by nitrogen than by phosphate due to extra phosphate inputs coming from various sources, such as domestic waste waters as well as the vertical mixing between upper and lower layers.Canakkale Onsekiz Mart University [COMU-BAP-2000/22]This short-term research program has been supported by Research Fund of the Canakkale Onsekiz Mart University (COMU-BAP-2000/22). We gratefully thank the Dr. Sukru Besiktepe, the former director, and Dr. Suleyman Tugrul, head of the Department of Chemical Oceanography, Institute of Marine Sciences, Middle East Technical University, and the technicians of the Institute of Marine Science, the Middle East Technical University (METU-IMS) for their help and instructions in nutrient analyses
Winter bloom of coccolithophore Emiliania huxleyi and environmental conditions in the Dardanelles
No full textFollowing a summer bloom of coccolithophore Emiliania huxleyi (Lohmann) Hay & Mohler, 1967, in 2003, a winter bloom was observed for the first time between late December 2003 and early January 2004 in the Dardanelles. Microscopic observations showed that the cell dimensions of E. huxleyi (Ehux) varied from 9.85 to 13.50 mu m in diameter (mean: 11.20 +/- 1.38 mu m). While Ehux revealed a relatively small population density (1.60 x 10(4) cells L-1) in early December 2003, the bloom started in middle December 2003 (7.86 x 10(6) cells L-1) and then peaked in early January 2004 (5.03 x 10(7) cells L-1) in the superficial layer. The peak dramatically decreased in late January 2004 (7.50 x 10(6) cells L-1). Ehux was the dominant species and represented about 90.0% of the phytoplankton assemblage. The bloom started flourishing after the diatom and dinoflagellate blooms under nitrogen depletion and moderate light, temperature and salinity conditions. Water temperature (10.31 +/- 1.14 degrees C) and salinity values (27.05 +/- 0.88 ppt) were usually stabile. Surface chlorophyll-a concentrations ranged from 1.23 to 2.32 mu g L-1 during the bloom. The ratios of N:P (mean: 4.12 +/- 2.22) and Si:P (40.35 +/- 16.25) of the bloom period were lower than those of the non-bloom periods.Turkish Scientific and Technical Research Council, Environmental, Atmospheric, Earth and Marine Sciences Research Group (TUBITAK-CAYDAG) [101Y081]This study was supported by the Turkish Scientific and Technical Research Council, Environmental, Atmospheric, Earth and Marine Sciences Research Group (TUBITAK-CAYDAG, project no. 101Y081)
Turkish truffles I: 18 new records for Turkey
No full textWOS: 000352486200014We report the first records of 18 truffle species in Turkey. Three belong to the Ascomycota: Elaphomyces leucocarpus, E. muricatus, and Genea sphaerica; and 15 to the Basidiomycota: Alpova corsicus, Gautieria otthii, G. retirugosa, G. trabutii, Hymenogaster citrinus, H. hessei, H. luteus, H. lycoperdineus, Hysterangium clathroides, H. epiroticum, H. fragile, H. nephriticum, Leucogaster tozzianus, Octaviania asterosperma, and Protoglossum aromaticum. We also report new localities within Turkey for Picoa juniperi, P. lefebvrei, Geopora cooperi, Terfezia arenaria, T. claveryi, Tuber aestivum, and T. nitidum in the Ascomycota; and Leucogaster nudus, Hymenogaster thwaitesii, H. vulgaris, and Melanogaster broomeanus in the Basidiomycota.Scientific and Technological Research Council of Turkey projectTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [T-BAG-111T530, BIDEB-2221]The first author received funding from the Scientific and Technological Research Council of Turkey project number T-BAG-111T530 and BIDEB-2221. We appreciate the help from Abdulkadir Simsek, Ahmet Oksuzoglu, Cemhan Bucak, Coskun Bilgi, Duran Celik, Ekrem Toprak, Esra Er, Fatih Kaya, Gulsum Turkoglu, Idris Sener, Kadir Bazlica, Kadir Ceryan, Mehmet Halil Solak, Mehmet Metin, Mehmet Yucel, Murat Kilic, Mustafa Demir, Mustafa Turuncoglu, Niyazi Ulucoban, Okan Kursun, Osman Coban, Serkan Sevinc, Seyit Ahmet Akay, Tolga Keser, Ugur Demirbilek, Veysel Kodalak, and Yavuzalp Turkoglu in the collection of some of the specimens
Çanakkale Bo?azı Kepez Limanında Kış Dönemi Fitoplankton, Nütrient ve Klorofil a Düzeylerinde Kısa Zaman Serili De?işimler
No full textThis study was carried out to determine the short time series of phytoplankton density and chlorophyll a in relation to nutrients and other environmental parameters in surface waters of Kepez Harbor in the Dardanelles in winter period of 02 December 2004 and 07 March 2005. Average temperature, salinity, pH, specific conductivity, TDS, DO, TSS, NO2-+NO3-, PO4-3, SiO4 and chlorophyll a were measured 9.47 degrees C, 27.5 ppt, 8.12, 42.86 mS cm(-1), 27.86 g L-1, 9.23 mg L-1, 27.1 mg L-1, 0.43 mu M, 0.23 mu M, 2.91 mu M, 1.919 mu g L-1, respectively. Both N:P (1.78) and Si:P ratios (14.9) were significantly lower than the assimilatory optimal Redfield ratio. Total phytoplankton density varied between 8.25E+04 and 4.71E+06 Cell L-1. Phytoplankton community structure was observed to be controlled by 3 dinoflagellates and 4 diatoms in the Dardanelles. However, also there were blooms of coccolithophoride Emiliania huxleyi in early December (2.36E+06 Cells L-1) and late February (1.57E+06 Cells L-1) and some silicoflagellates such as Diciyocha spp. in early February (2.36E+05 Cells L-1). Contribution of diatoms to total phytoplankton density (48.8%) was higher than the contribution of dinoflagellates (30.9%) and other taxonomic groups (20.3%). Relationships between chlorophyll a and diatoms (r=0.726), between chlorophyll a and dinoflagellates (r=0.579) and between chlorophyll a and other taxonomic groups (r=0.514) showed that chlorophyll a was highly controlled by diatoms than dinoflagellates and other taxonomic groups. On the other hand, short time distribution of phytoplankton revealed that there was growing 7 phytoplankton populations in the winter period. High chlorophyll a, nutrient, phytoplankton density and rational differences between major taxonomic groups revealed that the Dardanelles was connected with the process of eutrophication due to high terrestrial discharges coming from Black Sea surface waters via straits system and international carrying activities by vessels.COMU- BAP [2005/30]This study is funded by COMU- BAP Project 2005/30. The material in this manuscript was derived from a part of the master's thesis of Cenk Oner
Temporal variations of phytoplankton community and their correlation with environmental factors in the coastal waters of the Çanakkale Strait in 2018
No full textIn order to investigate temporal variations in phytoplankton connected with hydrography, high-resolution (twice a week) samplings were carried out between January and December 2018 at a single, shallow water station in the Dardanelles. Diatoms dominated in early and mid-winter, late spring and early summer, and between August and October. Whereas dinoflagellates dominated in the period from mid-February to the end of the third week of May, mid-summer, and late autumn. Other groups were generally more abundant in the early summer and mid-autumn than any other period. Late spring and early summer, mid-autumn and middle winter were the important bloom periods. The average contribution of diatom abundance (5.00 × 105±7.80 × 105 cells L−1) to average total phytoplankton abundance (9.63 × 105±7.88 × 105 cells L−1) was above 50% (average: 51.88%) during the year except spring (34.32%). However, the average contribution of dinoflagellates (43.32±20.69%) and others (4.81±6.99%) to the total phytoplankton abundance were lower than the abundance of the diatoms (51.88±21.61%). The study revealed a decrease both in the total number of algal blooms which also included HABs and their densities in the region compared to the previous findings. These observations seem to evidence environmental status improvement of the investigated area, manifested in an average chlorophyll a concentration (0.71±0.52 µg L−1) and quantitative phytoplankton structure (103 to 105 cells L−1)
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