Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - Scopus: 21Determination of Superoxide Dismutase Activities in Different Cyanobacteria for Scavenging of Reactive Oxygen Species(Taylor and Francis Ltd., 2015) Güneş, Seda; Tamburacı, Sedef; İmamoğlu, Esra; Dalay, Meltem ConkThere is considerable interest in cyanobacteria as sources of antioxidant pigments, antiinflammatory substances, enzymes such as superoxide dismutase (SOD) and vitamins. Antioxidant enzymes have significant role in the removal of reactive oxygen species produced during visible and ultraviolet irradiance stress in cyanobacteria. One of the most ubiquitous protective enzyme is superoxide dismutase (SOD). Most of cyanobacteria are known to have both FeSOD and MnSOD which are associated with photosystem I and II. These enzymes are responsible for scavenging superoxide radicals.Spirulina platensis and Synechococcus nidulans are widely used cyanobacteria as food supplement and cosmetic due to their bioactive compounds. Although the chemical composition of S.platensis has been investigated by many researchers, research on the relationship between protein content and comparison of SOD activity with other cyanobacteria is limited.Among several SOD producing cyanobacteria, the most promising organisms were investigate in terms of SOD activities in this study. The aim of the present work was to investigate and compare the SOD activities of different cyanobacteria including S. platensis, Pseudanabeana sp., S. nidulans and associate with protein contents. SOD activities of these cyanobacteria were determined by xanthine/xanthineoxidase method.Modified Lowry method was used for protein determination. The analysis results showed that the maximum specific SOD activity obtained was 50.4 U/mg from S.nidulans and the minimum specific SOD activity was 18.4 U/mg from Pseudanabeana sp. Total protein amount of S. nidulans, S. platensis, Pseudanabeana sp. was determined as 0.25 mg/ml, 0.27 mg/ml and 0.43 mg/ml respectively. As a result, Synechococcus nidulans was more efficient at scavenging peroxide radicals than Pseudanabeana sp. © 2015, © 2015 Har Krishan Bhalla & Sons.Article Citation - WoS: 11Citation - Scopus: 13Capsaicin Emulsions: Formulation and Characterization(Taylor and Francis Ltd., 2017) Akbaş, Elif; Söyler, Betül; Öztop, Mecit HalilOleoresin capsicum, the oil extract of chili pepper, is mainly composed of capsaicin. Capsaicin is a hydrophobic volatile compound exhibiting antimicrobial activity against various microorganisms. Capsaicin in the form of an emulsion-based carrier system could be a good alternative to enhance bioavailability and simultaneously to increase the shelf-life of food. In this study, capsaicin emulsions were formulated using three different surfactants (Tween 80, commercial soy lecithin, and sucrose monopalmitate/SMP). Effects of aqueous phase composition, pH, and heating the pre-homogenized dispersion were investigated. For characterization, NMR relaxometry, color, turbidity, and antioxidant activity experiments were conducted. Antimicrobial efficacies of the emulsions were also evaluated against Escherichia coli andStaphylococcus aureus. Mean particle sizes of emulsions with surfactants Tween 80, lecithin, and SMP were found to be 68.30, 582.63, and 50.10 nm, respectively. Lecithin-containing emulsions showed the highest antimicrobial activity against S. aureus with 4.60 log reduction, whereas the same effect was observed in Tween 80-containing emulsions against E. coli with 3.86 log reduction. Emulsions prepared with SMP showed the highest antioxidant activity with 0.482 mg DPPH/L emulsion. The formulated emulsions have the potential to be used in food industry as antimicrobial food grade solutions.Article Citation - WoS: 10Citation - Scopus: 10On the Helmholtz Theorem and Its Generalization for Multi-Layers(Taylor and Francis Ltd., 2016) Kuştepeli, AlpThe decomposition of a vector field to its curl-free and divergence-free components in terms of a scalar and a vector potential function, which is also considered as the fundamental theorem of vector analysis, is known as the Helmholtz theorem or decomposition. In the literature, it is mentioned that the theorem was previously presented by Stokes, but it is also mentioned that Stokes did not introduce any scalar and vector potentials in his expressions, which causes a contradiction. Therefore, in this article, Stokess and Helmholtzs representations are examined in detail to reveal and emphasize their differences, similarities and important points. The Helmholtz theorem is obtained for all kinds of spaces by using the theory of distributions in a comprehensive and rigorous manner with detailed explanations, which also leads to a new surface version of the Helmholtz theorem or a new surface decomposition, resulting in the canonical form; hence, it is different than the one suggested previously in terms of two scalar functions. The generalized form of the Helmholtz theorem is also presented by employing the same approach when there is a multi-layer on the surface of discontinuity, which also corresponds to the extension of the theorem to fields with singularities of higher order.Article Citation - WoS: 16Citation - Scopus: 16Screening of Damage Induced by Lead (pb) in Rye (secale Cereale L.) – a Genetic and Physiological Approach(Taylor and Francis Ltd., 2016) Özyigit, İbrahim İlker; Doğan, İlhan; İğdelioğlu, Sezen; Filiz, Ertuğrul; Karadeniz, Sedat; Uzunova, ZeynepThe fields in which lead (Pb) finds application in the modern world have increased dramatically in recent years. As a consequence of this intensive utilization of Pb, its toxicity tends to pose more and more environmental problems. The aim of this study was to evaluate the genotoxic potential of Pb and to characterize some physiological parameters in Secale cereale under Pb stress. Plants were subjected to different exposure levels of Pb (0, 100, 200 and 400 µmol/L) for two weeks. At the end of the experimental period, the effects of Pb exposure on the photosynthetic pigments content (chlorophyll a and b, total chlorophyll, chlorophyll a/b and carotenoids) and genetic material of S. cereale were studied. To evaluate the genotoxic effect of Pb, random amplified polymorphic DNA – polymerase chain reaction (RAPD-PCR) was employed. The obtained results showed alteration in the photosynthetic pigments content and RAPD-PCR profiles of S. cereale grown in the presence of Pb. The alterations in the RAPD-PCR profiles following Pb treatments appeared to be losses of normal bands and occurrences of new bands compared to unexposed plantlets. Overall, the content of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids decreased by 6.68%, 6.08%, 2.89% and 8.57%, respectively, under severe Pb stress (400 µmol/L).Article Citation - WoS: 18Citation - Scopus: 20Assessment of Cd-Induced Genotoxic Damage in Urtica Pilulifera L. Using Rapd-Pcr Analysis(Taylor and Francis Ltd., 2016) Doğan, İlhan; Özyiğit, İbrahim İlker; Tombuloğlu, Güzin; Sakçalı, Mehmet Serdal; Tombuloğlu, HüseyinPlants can be used as biological indicators in assessing the damage done by bioaccumulation of heavy metals and their negative impact on the environment. In the present research, Roman nettle (Urtica pilulifera L.) was employed as a bioindicator for cadmium (Cd) pollution. The comparisons between unexposed and exposed plant samples revealed inhibition of the root growth (∼25.96% and ∼45.92% after treatment with 100 and 200 µmol/L Cd concentrations, respectively), reduction in the total soluble protein quantities (∼53.92% and ∼66.29% after treatment with 100 and 200 µmol/L Cd concentrations, respectively) and a gradual genomic instability when the Cd concentrations were increased. The results indicated that alterations in randomly amplified polymorphic DNA (RAPD) profiles, following the Cd treatments, included normal band losses and emergence of new bands, when compared to the controls. Also, the obtained data from F1 plants, utilized for analysis of genotoxicity, revealed that DNA alterations, occurring in parent plants due to Cd pollution, were transmitted to the next generation.Article Citation - WoS: 2Citation - Scopus: 2A Computational Analysis of Turkish Makam Music Based on a Probabilistic Characterization of Segmented Phrases(Taylor and Francis Ltd., 2015) Bozkurt, Barış; Karaçalı, BilgeThis study targets automatic analysis of Turkish makam music pieces on the phrase level. While makam is most simply defined as an organization of melodic phrases, there has been very little effort to computationally study melodic structure in makam music pieces. In this work, we propose an automatic analysis algorithm that takes as input symbolic data in the form of machine-readable scores that are segmented into phrases. Using a measure of makam membership for phrases, our method outputs for each phrase the most likely makam the phrase comes from. The proposed makam membership definition is based on Bayesian classification and the algorithm is specifically designed to process the data with overlapping classes. The proposed analysis system is trained and tested on a large data set of phrases obtained by transferring phrase boundaries manually written by experts of makam music on printed scores, to machine-readable data. For the task of classifying all phrases, or only the beginning phrases to come from the main makam of the piece, the corresponding F-measures are.52 and.60 respectively.Article Citation - WoS: 1Citation - Scopus: 1Revised Distributional Forms of the Laplacian and Poisson's Equation, Their Implications, and All Related Generalizations(Taylor and Francis Ltd., 2015) Kuştepeli, AlpThe theory of distributions of L. Schwartz is a very useful and convenient way for the analysis of physical problems since physical distributions, especially charge distributions yielding the discontinuity of the potential and boundary conditions, can be correctly described in terms of mathematical distributions. To obtain the charge distributions, the distributional form of the Laplacian is applied to the Poisson's equation; therefore, for the correct representations and interpretations, the distributional forms and their proper applications are very important. In this article, it is shown that the distributional form of the Laplacian has been presented by Schwartz and also others with a missing term, leading to confusing and wrong results mathematically, and as a result electromagnetically; and the revised, correct, and complete distributional representations of the Laplace operator, the Poisson equation, and double layers, defined as the dipole layer and equidensity layer, are obtained and presented with detailed discussions and explanations including boundary conditions. By using the revised form of the Laplacian, Green's theorem is obtained explicitly with special emphases about important points and differences with previous works. The generalized forms of the Laplacian, Poisson's equation, charge densities, boundary conditions, and Greens theorem are also presented when there is a multi-layer on the surface of discontinuity.Article Citation - WoS: 5Citation - Scopus: 8Usul and Makam Driven Automatic Melodic Segmentation for Turkish Music(Taylor and Francis Ltd., 2014) Bozkurt, Barış; Karaosmanoglu, M. Kemal; Karaçalı, Bilge; Ünal, ErdemAutomatic melodic segmentation is a topic studied extensively, aiming at developing systems that perform grouping of musical events. Here, we consider the problem of automatic segmentation via supervised learning from a dataset containing segmentation labels of an expert. We present a statistical classification-based segmentation system developed specifically for Turkish makam music. The proposed system uses two novel features, a makam-based and an usul-based feature, together with features commonly used in literature. The makam-based feature is defined as the probability of a note to appear at the phrase boundary, computed from the distributions of boundaries with respect to the piece’s makam pitches. Likewise, the usul-based feature is computed from the distributions of boundaries with respect to beats in the rhythmic cycle, usul of the piece. Several experimental setups using different feature groups are designed to test the contribution of the proposed features on three datasets. The results show that the new features carry complementary information to existing features in the literature within the Turkish makam music segmentation context and that the inclusion of new features resulted in statistically significant performance improvement.Article Citation - WoS: 27Citation - Scopus: 31Statistical Analysis of Causes of Death (2005-2010) in Villages of Simav Plain, Turkey, With High Arsenic Levels in Drinking Water Supplie(Taylor and Francis Ltd., 2015) Gündüz, Orhan; Bakar, Coşkun; Şimşek, Celalettin; Baba, Alper; Elçi, Alper; Gürleyük, Hakan; Mutlu, Merdiye; Çakır, AyşeThe purpose of this research was to compare the causes of death in 5 villages situated in Simav Plain, Turkey, during 2005-2010 where different arsenic levels were detected in drinking water supplies. Since groundwater in Simav Plain had arsenic concentrations that ranged between 7.1 and 833.9 ppb, a two-phase research was formulated. In the first phase, public health surveys were conducted with 1,003 villagers to determine the distribution of diseases. In the second phase, verbal autopsy surveys and official death records were used to investigate the causes of death. In total, 402 death cases were found in the study area where cardiovascular system diseases (44%) and cancers (15.2%) were major causes. Cancers of lung (44.3%), prostate (9.8%), colon (9.8%), and stomach (8.2%) were comparably higher in villages with high arsenic levels in drinking water supplies. Furthermore, the majority of cases of liver, bladder, and stomach cancers were observed in villages with high arsenic levels. © 2015 Taylor and Francis Group, LLC.Article Citation - WoS: 2Citation - Scopus: 2A Biomathematical Model for Phoma Tracheiphila Citrus Resistance Screening(Taylor and Francis Ltd., 2012) Khanchouch, Khaled; Hajlaoui, Mohamed Rabeh; Kutucu, HakanThe causal agent of Mal Secco, Phoma tracheiphila, is responsible for many important losses in the Citrus crop worldwide. The resistance enhancement of Citrus susceptible to the pathogen infection depends on the availability of a valid test for disease assessment. However, the resistance analysis tests used give controversial results. In this paper, we propose a new mathematical model to conduct a rapid and efficient resistance screening test. This model has the advantage to give a strict evaluation of the resistance and not a relative estimation as in the usual tests. The results obtained by this model are in concordance with those observed in the orchards.
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