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2000

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Articles 2011 - 2040 of 2418

Full-Text Articles in Life Sciences

Estuarine Relationships Between Zooplankton Community Structure And Trophic Gradients, Gyung Soo Park, Harold G. Marshall Jan 2000

Estuarine Relationships Between Zooplankton Community Structure And Trophic Gradients, Gyung Soo Park, Harold G. Marshall

Biological Sciences Faculty Publications

Zooplankton and water quality parameters were investigated at eight mesohaline stations in the lower Chesapeake Bay and Elizabeth River from January through December 1994 to identify the changes of zooplankton community structure with increased eutrophication. The total micro- and mesozooplankton biomass decreased with the increase of eutrophication. However, the relative proportion of microzooplankton increased with increased eutrophication. Within highly eutrophied waters, the small oligotrichs (m) and rotifers dominated the total zooplankton biomass (as carbon). However, tintinnids, copepod nauplii and mesozooplankton significantly decreased with the increase of eutrophication. These patterns were consistent throughout the seasons and had significant relationships statistically. These …

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Hyaluronidases Of Gram-Positive Bacteria, Wayne L. Hynes, Sheryl Lynne Walton Jan 2000

Hyaluronidases Of Gram-Positive Bacteria, Wayne L. Hynes, Sheryl Lynne Walton

Biological Sciences Faculty Publications

Bacterial hyaluronidases, enzymes capable of breaking down hyaluronate, are produced by a number of pathogenic Gram-positive bacteria that initiate infections at the skin or mucosal surfaces. Since reports of the hyaluronidases first appeared, there have been numerous suggestions as to the role of the enzyme in the disease process. Unlike some of the other more well studied virulence factors, much of the information on the role of hyaluronidase is speculative, with little or no data to substantiate proposed roles. Over the last 5 years, a number of these enzymes from Gram-positive organisms have been cloned, and the nucleotide sequence determined. …

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Genetically Modified Foods And Organisms: What In The World ...?, Bridget M. Lyons, Teresa Ralabate, Marion Calabrese, Linda Hadfield Jan 2000

Genetically Modified Foods And Organisms: What In The World ...?, Bridget M. Lyons, Teresa Ralabate, Marion Calabrese, Linda Hadfield

WCBT Faculty Publications

This paper examines the current controvery over genetically modified organisms and foods and compares the regulatory response in the United States, European Union and United Kingdom.

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The Cytogenetic Effects Of Npyr On Mice, Mehmet Korkmaz, Ahmet Çolak Jan 2000

The Cytogenetic Effects Of Npyr On Mice, Mehmet Korkmaz, Ahmet Çolak

Turkish Journal of Biology

The effects of N-nitrosopyrrolidine (NPYR) on mice chromosomes and micronucleus induction were investigated in order to evaluate its genotoxic effects. Twenty 10-12 week old mice and 40 8- 10 week old male mice ( Mus musculus var. albinos) were used for chromosome analysis without sex discrimination and micronucleus tests respectively. Mice were intraperitoneally treated in single injections with three dose levels (100, 200 and 300 mg/kg) of NPYR with isotonic saline as the solvent vehicle. Bone marrow was sampled at 24 and 48 h postinjection. Examination of the mice bone marrow chromosomes at the metaphase (24 h) showed that in …

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A Quantitative And Qualitative Study On The Phytoplankton Of Palandöken Pond, Hasan Gürbüz, Zekeri̇ya Altuner Jan 2000

A Quantitative And Qualitative Study On The Phytoplankton Of Palandöken Pond, Hasan Gürbüz, Zekeri̇ya Altuner

Turkish Journal of Biology

In this research, the phytoplankton community of Palandöken pond was investigated quantitatively and qualitatively in samples taken vertically from the surface to 10 m depth between October 1990 and October 1992. The physical and chemical properties of the pond water were also determined. 99 taxa were determined in the phytoplankton and the proportions of them were as follows: Bacillariophyta 79%, Chlorophyta 10%, Cynophyta 6%, Euglenophyta 5%. The phytoplankton generally increased in the spring and early fall whereas in the summer and late fall it decreased. Physical factors had the greatest effect on phytoplankton growth.

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The Monthly Variations Of Blood Glucose Level Of Capoeta Tinca Capoeta(Heckel, 1843) In Çoruh Basin-Oltu Stream, Ayhan Yildirim, Mustafa Türkmen, İrfan Altuntaş Jan 2000

The Monthly Variations Of Blood Glucose Level Of Capoeta Tinca Capoeta(Heckel, 1843) In Çoruh Basin-Oltu Stream, Ayhan Yildirim, Mustafa Türkmen, İrfan Altuntaş

Turkish Journal of Biology

In this study, the monthly variation of blood glucose level of Capoeta tinca caught from in Çoruh Basin - Oltu Stream, between Augist 1995 and June 1996 was determined. It was determined that the average blood glucose level was 86.19±3.86 mg/dl in males and 83.58±3.77 mg/dl in females. The blood glucose level was highest (116.36±8.58 mg/dl) in April, and lowest (51.00±7.10 mg/dl) in June.

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Detection Of Mutagenic Effects Of 2, 4, 5 Tri (Sübstitüe) Phenyl Imidazole And Its Derivatives In Ames/Salmonella/Test System, Ayşe Mercangöz, Berri̇n Ayaz Tüylü Jan 2000

Detection Of Mutagenic Effects Of 2, 4, 5 Tri (Sübstitüe) Phenyl Imidazole And Its Derivatives In Ames/Salmonella/Test System, Ayşe Mercangöz, Berri̇n Ayaz Tüylü

Turkish Journal of Biology

The mutagenic effects of 2, 4, 5 tri-phenylimidazole and its nine different derivatives, which are aimed at producing medicine as a primary substance, were investigated by the Ames Salmonella/Microsome plate assay. The test compounds were directly effective, especially in the TA 98 strain. A relationship was found between the mutagenic effect and the positions of the methyl and methoxy groups.

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The Inhibition Effect Of Yoghurt Starter Culture Metabolites, Belma Aslim, Yavuz Beyatli, Kadi̇r Halkman Jan 2000

The Inhibition Effect Of Yoghurt Starter Culture Metabolites, Belma Aslim, Yavuz Beyatli, Kadi̇r Halkman

Turkish Journal of Biology

In this study effect of some separate and combined metabolic compounds produced by lactic acid were tested on food pathogenic and contaminant microorgnasms. For this study, five strains of each Lactobacillus bulgaricus and Streptococcus thermophilus were used. The inhibition effects of the metabolic products (lactic acid, hydrogen peroxide, acetaldehyde, diacetyl) produced by the stains on test bacteria ( Staphylococcus aureus, Escherichia coli) were determined. Also, a random combinations of the strains were prepared and the metabolic compounds produced by these cultures and their antimicrobial activities on tested bacteria were determined. By regarding the metabolic products mainly, the samples of lactic …

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The Effects Of Malt Extract And Corn Strach On The Vegetativedevelopment And Morphology Of The Pleurotus Floridafovose Mycelia, Abdunnasir Yildiz Jan 2000

The Effects Of Malt Extract And Corn Strach On The Vegetativedevelopment And Morphology Of The Pleurotus Floridafovose Mycelia, Abdunnasir Yildiz

Turkish Journal of Biology

No statistical differences were determined in the effects of malt extract (ME) and corn strach (CS) doses on the vegetative development of mycelia (P>0.05). The mycelia in all gropus covered 9.0 cm agar plates in 9.0 days and some characteristic differences, development from (vertical or horizontal), cluster formation, tickening and tissue formations, were observed. In the group containing 2% CS, the mycelia formed a sparse development horizontally on the surface and center of the agar plate, whereas clustering, thickening and tissue formation wereobserved in the form of a thick zone on the edges of the petri dishes. In 1.5% …

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Changes In Liver Cytoplasmic Glutathione-S-Transferase And Microsomalnitrosodimethylamine Demethylase Activities In Chicks Obtainedfollowing Daminozide Treatment, Yavuz Si̇li̇ğ, V. Kenan Çeli̇k, Ati̇lla Atalay Jan 2000

Changes In Liver Cytoplasmic Glutathione-S-Transferase And Microsomalnitrosodimethylamine Demethylase Activities In Chicks Obtainedfollowing Daminozide Treatment, Yavuz Si̇li̇ğ, V. Kenan Çeli̇k, Ati̇lla Atalay

Turkish Journal of Biology

In this study, microsomal nitrosodimethylamine demethylase (NDMAd) and cytoplasmic glutathione-s-tarnsferase (GST) activities in the livers of chicks obtained from the LD 10 (3 mg/ml) and LD 30 (9 mg/ml) doses of daminozide (Succinic acid 2,2-Dimethylhydrazide) injected Ross-Pm-3 fertilized chicken eggs were investigated. Spectrophotometric determination of NDMAd activity was performed at 412 nm by the detection of yellow coloured compound formed as a product of the reaction of formaldehyde with Nash reagent. No significant increase was observed in NDMAd activity (P>0.05) of the group treated with LD 10 dose although NDMAd activity was found to be significantly increased (P

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The Effect Of Olive Oil Mill Effluent On The Mitotic Cell Division And Total Protein Amount Of The Root Tips Of Triticum Aestivuml., Mehmet Aybeke, Göksel Olgun, Uğur Sidal, Dürdane Kolankaya Jan 2000

The Effect Of Olive Oil Mill Effluent On The Mitotic Cell Division And Total Protein Amount Of The Root Tips Of Triticum Aestivuml., Mehmet Aybeke, Göksel Olgun, Uğur Sidal, Dürdane Kolankaya

Turkish Journal of Biology

In this work sitotoxic and mutagenic effects Olive Oil Mill Effluent (OOME) on the root tips of Triticum aestivumL. were investigated. In this purpose, germination rate of seeds, mitotic division abnormalities and total protein amounts were evaluated. The seeds kept in various OOME concentrastions, it was determinated that germination rate decreased, whilst mitotic abnormalities and mitotic cell division frequency increased. Especially, the increased cell division frequency was of significance, almost several times higher than the control group. The cells having multinucleus or fragmented nucleus and numerical or sutructural mutations were also found. Furthermore it was observed that total protein amounts …

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Antioxidant Enzymes Activities In Chemically Warfared Samples Ofdociostaurus Maroccanusobtained From An Epidemic Population, Aysun Özkan, Gülgün Gündüz, Battal Çiplak, Kayahan Fişkin Jan 2000

Antioxidant Enzymes Activities In Chemically Warfared Samples Ofdociostaurus Maroccanusobtained From An Epidemic Population, Aysun Özkan, Gülgün Gündüz, Battal Çiplak, Kayahan Fişkin

Turkish Journal of Biology

Antioxidant enzyme activities at first, second, third nymphal stage and adult individuals of nition [O-O-dimethyl-O-(3-methyl-4-nitro-phenyl) phosphorothioate] administered D. maroccanusare investigated. Living specimens where nition had been administered for chemical contention by Agricultural Head Office of Antalya Province in 1996 were taken from epidemic population of Eynif plain (Ibradi, Antalya). Catalase, GSH-reductase, GSH-peroxidase and Se-dependent-GSH-peroxidase activities are assayed spectorofotometrically. The catalase activity did indicate no significant change in any nymphal stage. GSH-reductase activity increased in adult individuals. Se-GSH-peroxidase activity decreased with second nymphal stage and increased with the third one, Whereas GSH-peroxidase activity increased at second nymphal stage of D. maroccanus.

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The Effect Of Some Nutrients Supplementation To Synthetic Compostwith Wheat Straw Before Mycel Inoculation, On Mycelium Growth, Yieldand Early Ripe Of Agaricus Bitorquis(Quél). Sacc, Hasan Hüseyi̇n Doğan, Celaleddi̇n Öztürk, Cengi̇z Akköz Jan 2000

The Effect Of Some Nutrients Supplementation To Synthetic Compostwith Wheat Straw Before Mycel Inoculation, On Mycelium Growth, Yieldand Early Ripe Of Agaricus Bitorquis(Quél). Sacc, Hasan Hüseyi̇n Doğan, Celaleddi̇n Öztürk, Cengi̇z Akköz

Turkish Journal of Biology

The effect of some nutrients added to synthetic compost with wheat straw, on mycelium growth, yield and early ripe of Agaricus bitorquis (Quél.) Sacc. were investigated. The compost was prepared by fermentation and chemical disinfection methods. Corn flour, wheat flour, hen grain, soybean meal and sunflower seed hulls were used as additional nutrients. The experiments were made at the temperatüre 20-22°C and 80-90% relative humidity in the yield rooms. The shortest mycelium growth period (average 14 days) were determined in containing 350 g/10 kg and 450 g/10 kg sunflower seed hulls. The maximum production were taken in the sacks of …

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Effects Of Gibberellic Acid On Male Sterility, Seed Yield And Oil And Fatty Acid Syntheses Of Safflower ( Carthamus Tinctorius L.), Hasan Baydar Jan 2000

Effects Of Gibberellic Acid On Male Sterility, Seed Yield And Oil And Fatty Acid Syntheses Of Safflower ( Carthamus Tinctorius L.), Hasan Baydar

Turkish Journal of Biology

The purpose of this study was to determine the effects of gibberellic acid (GA 3 ) on male and female sterility, seed yield, oil and fatty acid syntheses, growth and development properties in safflower ( Carthamus tinctorius var. Yenice). GA 3 was applied in five different doses at three different stages, and induced male sterility at a rate of up to 93.0%. This finding has important implications for the practical use of GA 3 in hybrid seed production. GA 3 applications significantly decreased the seed yield per plant both in isolation and non-isolation. Although fatty acid syntheses did not change …

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The Use Of Random Amplified Polymorphic Dna(Rapd) Markers In Sex Discrimination In Niletilapia, Oreochromis Niloticus (Pisces: Cichlidae), Fevzi̇ Bardakci Jan 2000

The Use Of Random Amplified Polymorphic Dna(Rapd) Markers In Sex Discrimination In Niletilapia, Oreochromis Niloticus (Pisces: Cichlidae), Fevzi̇ Bardakci

Turkish Journal of Biology

Random amplified polymorphic DNA (RAPD) markers were successfully used in discrimination of sexes in Nile tilapia fish ( Oreochromis niloticus) using linear discriminant function analysis. The results provide support for the view that major genetical sex determining factors exist in tilapia.

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Morphological Changes In Xenopus Laevisembryoswith Lithium And Evaluation Of The Fetax Test, Ayper Boğa, Seçi̇l Bi̇nokay, Ayşe Kendi̇rci̇, Tuncay Özgünen, Emi̇ne Kizilkanat Jan 2000

Morphological Changes In Xenopus Laevisembryoswith Lithium And Evaluation Of The Fetax Test, Ayper Boğa, Seçi̇l Bi̇nokay, Ayşe Kendi̇rci̇, Tuncay Özgünen, Emi̇ne Kizilkanat

Turkish Journal of Biology

The main goal was to standardize the FETAX (Frog Embryos Teratogenesis Assay: Xenopus) test. Since lithium ions are known to be teratogenic for embryos of many organisms, they were prefferred for our first standardization assay. Xenopus laevis embryos were exposed to lithium chloride (from 2x10 -4 to 6 x 10 -3 M concentrations) for 96 hours at 2-4 cell stages of development. Exposure to lower LiCl concentrations permitted larvae to survive and to develop into normal ones. On the other hand, depending on the increase in the LiCl concentration, the body length and survival rate (%) decreased. In addition, the …

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Simple Production And Purification Of Monoclonalantibodies In Serum-Free Medium, Aynur Başalp, Beyazit Çirakoğlu, Engin Bermek Jan 2000

Simple Production And Purification Of Monoclonalantibodies In Serum-Free Medium, Aynur Başalp, Beyazit Çirakoğlu, Engin Bermek

Turkish Journal of Biology

Although serum is a main source of essential nutrients and growth factors, its use creates highly complex and poorly defined media. The use of serum-free media is more efficient than the use of media containing serum especially when the purification and characterization of antibodies are considered. In this study, we developed a serum-free medium system for cultivation of hybrid cells producing monoclonal antibodies specific for Tobacco Mosaic Virus (1F5) and 17\beta-estradiol (10F4) (15D4). Cells were cultivated in a medium with 10 % FCS for three days, and subsequently in serum-free medium for two days. The procedure was repeated once again …

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Analysis Of Functional Domains On Glutamatesynthase, Barbaros Nalbantoğlu Jan 2000

Analysis Of Functional Domains On Glutamatesynthase, Barbaros Nalbantoğlu

Turkish Journal of Biology

Glutamate synthases (GOGAT) were analyzed to identify the functional binding domains of the substrate (glutamine) and cofactors (FMN, NAD(P)H, FAD, [3Fe-4S]1+,0 and [4Fe-4S]2+,1+ clusters and ferredoxin) on this enzyme. The published amino acid sequences of six different NAD(P)H-dependent GOGATs (NAD(P)H-GOGAT) and ten different ferredoxin-dependent GOGATs (Fd-GOGAT) were used for this analysis. The amino acid sequences of these sixteen GOGATs were compared with the amino acid sequences of aminotransferases for glutamine, flavoproteins for FMN, flavoproteins and pyridine-nucleotide-dependent enzymes for FAD and NAD(P)H, iron-sulfur proteins for [3Fe-4S] 1+,0 and [4Fe-4S]2+,1+ clusters and ferredoxin-dependent enzymes for ferredoxin. It was determined that Fd-GOGAT has …

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Hydrophobicities And Electrostatic Behavior Ofdifferent Micro-Organisms, Abbas Yousefi Rad, Hakan Ayhan, Erhan Pi̇şki̇n, Özgül Kisa Jan 2000

Hydrophobicities And Electrostatic Behavior Ofdifferent Micro-Organisms, Abbas Yousefi Rad, Hakan Ayhan, Erhan Pi̇şki̇n, Özgül Kisa

Turkish Journal of Biology

The surface properties of 7 different micro-organisms with their 14 different strains were examined. The contact angles of the micro-organism films were measured by a captive-bubble technique. Surface free energies were calculated from the contact angles. Hydrophobicities were also evaluated by adhesion to p-xylene. The zeta potentials and surface charges of the micro-organisms were measured using a zeta potential analyser system. The contact angles of the gram positive micro-organisms, gram negative micro-organisms and Candida ablicans were in the ranges 48-70°, 43.5-55°, and 69-75° respectively, while the corresponding surface free energies were in the ranges 44.9-60.4 erg.cm -2 , 55.3-61.8 erg.cm …

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Effects Of Various Physiological Stresses Ontranscription Of The Suc2gene In The Yeastsaccharomyces Cerevisiae, Sezai̇ Türkel Jan 2000

Effects Of Various Physiological Stresses Ontranscription Of The Suc2gene In The Yeastsaccharomyces Cerevisiae, Sezai̇ Türkel

Turkish Journal of Biology

Physiological conditions in the growth habitat of yeast cells dramatically changes the gene expression pattern. In this study, it was shown that transcription of the SUC2gene, which encodes the cytoplasmic and secreted enzyme invertase, is modulated according to the environmental conditions in the yeast Saccharomyces cerevisiae. Hyperosmotic stress and oxidative stress repressed the transcription of the SUC2gene up to 50%. However, preconditioning of the yeast cells prevented the negative effects of osmotic stress on SUC2gene transcription. These results clearly show that, apart from the control of invertase activity and its secretion, osmotic stress and oxidative stress also represses transcription of …

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Hepatitis C Virus: Genome Organization, Viralproteins And Implications In Disease Pathogenesis, Çağla Eroğlu, Ergün Pinarbaşi Jan 2000

Hepatitis C Virus: Genome Organization, Viralproteins And Implications In Disease Pathogenesis, Çağla Eroğlu, Ergün Pinarbaşi

Turkish Journal of Biology

The hepatitis C virus (HCV) infection is a significant cause of morbidity and mortality worldwide. Infection with HCV becomes chronic in more than 80% of cases and it accounts for 20% of all cases of acute hepatitis. The hepatitis C virus was first identified by the molecular cloning of the virus genome in 1989. It is an enveloped, positive strand RNA virus with a genome size of around 9.5 kilobases. The single-stranded RNA genome of the virus contains a large open reading frame that encodes a large polyprotein of 3,010 to 3,033 amino acids shown to be processed by a …

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Monitoring Of Germin Synthesis By Pre-Absorbedanti-Germin Serum, Mahmut Çalişkan, Andrew C. Cuming Jan 2000

Monitoring Of Germin Synthesis By Pre-Absorbedanti-Germin Serum, Mahmut Çalişkan, Andrew C. Cuming

Turkish Journal of Biology

The transition of a quiescent plant embryo into a vigorously growing embryo revealed some nascent synthesis of gene products, among them germin has been characterized. Germin is a water soluble homopentameric glycoprotein whose synthesis and accumulation appear to be closely related to early wheat embryo development. Germin synthesis was monitored by employing an anti-germin serum which had been pre-adsorbed with wheat extract and optimized in order to decrease nonspecific binding. Germin accumulation was shown to occur in germinating embryos from 16h up to 6 day post-imbibition. Germin as a rare protein in wheat seedlings was detected as a dark band …

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The Effect Of Kinetin, Gibberellic Acid And Indoleacetic Acid On Ems-Induced Somatic Mutation Andrecombination In Drosophila Melanogaster, Eli̇f Yeşi̇lada Jan 2000

The Effect Of Kinetin, Gibberellic Acid And Indoleacetic Acid On Ems-Induced Somatic Mutation Andrecombination In Drosophila Melanogaster, Eli̇f Yeşi̇lada

Turkish Journal of Biology

The effect of plant growth hormones (kinetin, gibberellic acid (GA 3) and indole acetic acid (IAA)) on EMS-induced mutant wing spots was studied with the somatic mutation and recombination test (SMART) in Drosophila melanogaster.GA 3 reduced all kinds of EMS-induced spot. While a 10 -3 M concentration of kinetin reduced only the number of EMS-induced twin spots, a 10 -4 M concentration was seen to increase the number of all types of spot. The same concentrations of IAA gave variable results. A 10 -4 M concentration of IAA caused a decrease only in the number of large single spots. Our …

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Susceptibility Of Chickpea ( Cicer Arietinuml.)Cultivars To Agrobacterium Tumefaciens(Smith Andtownsend) Conn, Azi̇z Karakaya, Sebahatti̇n Özcan Jan 2000

Susceptibility Of Chickpea ( Cicer Arietinuml.)Cultivars To Agrobacterium Tumefaciens(Smith Andtownsend) Conn, Azi̇z Karakaya, Sebahatti̇n Özcan

Turkish Journal of Biology

Twelve chickpea cultivars grown in Turkey were assessed for susceptibility to wild-type Agrobacterium tumefaciens strains A281 and A136NC. Although all chickpea cultivars showed susceptibility to infection from both A. tumefaciens strains, Diyar-95, Flip 87-8, Ispanyol, Gökçe, Damla-89, and Aziziye-94 had higher frequencies of tumor formation from both strains than the other cultivars tested.

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Am1 Treatment Of Some Phenoxyacetic Acidherbicides, Lemi̇ Türker Jan 2000

Am1 Treatment Of Some Phenoxyacetic Acidherbicides, Lemi̇ Türker

Turkish Journal of Biology

AM1-type semiempirical quantum chemical calculations were carried out to explain differences in herbicidal activity between certain phenoxyacetic acid derivatives. It was found that the proper orientation and shape of the COOH group and the phenyl moiety both mutually and individually affected the observed activities.

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Freeliving Ciliates Of Pure And Soils Polluted Byconstituents Of Oil Lifting At Apsheron Peninsula, İlham Kh Alekperov Jan 2000

Freeliving Ciliates Of Pure And Soils Polluted Byconstituents Of Oil Lifting At Apsheron Peninsula, İlham Kh Alekperov

Turkish Journal of Biology

The data compiled during five-year-long investigation on the influence of drilling water and crude oil on specific composition, number and structure of the communities of free-living soil ciliates is presented. The vertical distribution of ciliates and their colonizing potential in the sterile soil monoliths placed in clean and polluted soils was studied on the basis of their survival and physiological responses. The changes in certain ciliate species were demonstrated by biotesting of the influence of various concentrations of drillinig water, crude oil and drillinig muds on these ciliates.

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Longevity In Some Wild Type And Hybrid Strains Ofdrosophila Melanogaster, Şükran Çakir, Ali̇ Ni̇hat Bozcuk Jan 2000

Longevity In Some Wild Type And Hybrid Strains Ofdrosophila Melanogaster, Şükran Çakir, Ali̇ Ni̇hat Bozcuk

Turkish Journal of Biology

It is known that aging is a multifactorial mechanism composed of both genetic and environmental components. The main evolutionary theories of aging are antagonistic pleiotropy and mutation accumulation, neither of which has substantial experimental support yet. In this study, the longevities of three wild type strains of Drosophila melanogaster and F1 hybrids derived from them were determined. Heterosis caused an increase in the adult lifespan of F1 hybrids.

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The Effect Of Calcium Concentration Of Water Onchloride Cell Density In Gill Of Brown Trout(Salmo Trutta L.) Larvae, Meti̇n Çalta Jan 2000

The Effect Of Calcium Concentration Of Water Onchloride Cell Density In Gill Of Brown Trout(Salmo Trutta L.) Larvae, Meti̇n Çalta

Turkish Journal of Biology

The effects of the calcium concentration on chloride cell (mitochondria-rich cell) density in the gills of brown trout ( Salmo trutta L.) larvae were studied. For this purpose, animals were divided into 3 groups 2 weeks after hatching and each groups was exposed to different calcium concentrations of water for two weeks. The results showed that the number of chloride cells in gill arch epithelia of larval fish increased with decreased calcium concentration.This increase was statistically significant in the gills of larvae kept in zero-Ca 2+ freshwater (ZCWF) ( P< 0.001 ) and of those kept in low-Ca 2+ freshwater (LCFW) ( P< 0.05) in comparision with the gills of larvae kept in normal freshwater (NFW).

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In Situ Germination Of Pollen Tetrads In Periplocagraceae L. (Periplocaceae), Feruzan Dane Jan 2000

In Situ Germination Of Pollen Tetrads In Periplocagraceae L. (Periplocaceae), Feruzan Dane

Turkish Journal of Biology

The mature anthers in large flower buds of Periploca graceae L. ( Periplocaceae ) were examined cytologically. It was seen that pollen was retained in permanent tetrads. Pollen tetrads were usually observed as isobilateral, rarely as linear. It was also observed that pollen tetrads germinated within the anther loculi. Most of the pollen tetrads were well stained and the germination rate was 90 %. In in situ germinated pollen tetrads, 1-4 pollen tubes were observed. During germination of pollen tetrads, the behavior of the nuclei was normal. At the early stage of pollen tube formation, a vegetative nucleus and two …

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Isolation, Characterization And Identification Ofthiram-Degrading Microorganisms From Soilenrichment Cultures, Nuretti̇n Şahi̇n, Abdurrahman Üsame Tamer Jan 2000

Isolation, Characterization And Identification Ofthiram-Degrading Microorganisms From Soilenrichment Cultures, Nuretti̇n Şahi̇n, Abdurrahman Üsame Tamer

Turkish Journal of Biology

Mixed microbial cultures were obtained by enrichment from soil samples collected from the Gediz basin. A number of species of bacteria and fungi were isolated and partially characterized from enrichment clutures containing the fungicide thiram. According to their responses in morphological and biochemical tests fungi were identified as Aspergillus niger, A. flavus and Penicilium steckii. Bacterial isolates were assigned to the genera: Bacillus, Arthrobacter, Moraxella-like Acinetobacter and Streptomyces. Islates grew in a mineral salts medium containing 0.2 mg/ml thiram and no growth factors were required.

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