Browsing by Author "Ay, G"

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    Setting order promising times in a supply chain network using hybrid simulation-analytical approach: An industrial case study
    Tunali, S; Ozfirat, PM; Ay, G
    Supply chain management (SCM) involves the management of material and information flow among the members of chain such as vendors, manufacturing plants and distribution centers. The main processes in supply chain are production planning, control, distribution and logistics. Effective management of all these processes provides the manufacturing companies great advantages in time based competition. In order to gain a competitive edge, firms must be able to deliver their products fast and on-time. This can be managed by better production planning, scheduling and due-date setting. This paper suggests a hybrid approach for setting realistic order due dates for a produce-to-order manufacturing company operating within a supply chain environment. The proposed hybrid approach combines mathematical and simulation modeling to bring together the advantages of both approaches. (C) 2011 Elsevier B. V. All rights reserved.
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    Effects of allergen specific immunotherapy on functions of Th and Treg cells in patients with seasonal allergic rhinitis
    Kirmaz, C; Kirgiz, O; Degirmenci, P; Yilmaz, Ö; Vatansever, S; Ozbilgin, K; Onur, E; Celik, O; Sogut, A; Ay, G; Yuksel, H
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    Effects of allergen-specific immunotherapy on functions of helper and regulatory T cells in patients with seasonal allergic rhinitis
    Kirmaz, C; Kirgiz, OO; Bayrak, P; Yilmaz, O; Vatansever, S; Ozbilgin, K; Onur, E; Celik, O; Sogut, A; Ay, G; Yuksel, H
    Background. Seasonal allergic rhinitis (SAR) is characterized by a helper T (Th)2 cell-mediated immune response at the target site. There is a relative Th1 and/or regulatory T (Treg) cell insufficiency in patients with SAR. It has been demonstrated that there is a change in the balance between these cells after allergen-specific immunotherapy (SIT), which is a curative treatment modality for this disease. However, there are few studies that evaluate the number and function of these cells in the inflammatory area after SIT treatment. Objective. We aimed to investigate the distribution of Th1, Th2 and Treg cells in nasal biopsies and lavage fluid (NLF) specimens from patients with SAR, before and after SIT. Methods. Twenty-four, symptomatic SAR patients sensitized to Olea europeae, were enrolled in the study prior to treatment. Fifteen, non-allergic subjects with nasal septum deviation, who needed surgical treatment, served as the control group. NLF and inferior turbinate biopsies were obtained from both groups during the pollen season. Conventional, subcutaneous SIT with Olea europeae extract was initiated in patients with SAR. One year after the first biopsy, biopsies and NLF specimens were again obtained for reevaluation. All biopsies were evaluated for Th1, Th2 and Treg cell counts by means of their transcription factors (T-bet, GATA-3 and FoxP3) using an immunohistochemical analysis method. Additionally, all NLF specimens were evaluated for the functions of these cells, by means of their specific cytokines, using an ELISA method. Results. When the basal status of those patients with SAR was evaluated based on transcription factors, prior to treatment, Th1 and Treg cells were found to be fewer than in non-allergic controls (p=0.001 for both T-bet and FoxP3). It was demonstrated that numbers of GATA-3-carrying cells, which are a marker for Th2, were not significantly different between the groups (p=0.276), but evaluation of the Th1/Th2 ratio revealed a relative Th2 dominance in patients with SAR prior to treatment. When evaluated on the basis of cytokine levels, it was observed that Th1-originated IFN-gamma was lower in patients with SAR compared to the control group, both before and after treatment (p=0.012 for both comparisons), Th2-originated IL-4 levels were not significantly different between the groups either before or after treatment (p=0.649, p=0.855; respectively). Th2- and Treg cell-originated IL-10 levels were higher in patients with SAR before treatment (p=0.033), but this difference was not statistically signifact following treatment compared with controls (p=0.174). Treg cell-originated TGF-beta levels were slightly lower in patients with SAR compared to the controls, although the difference was not statistically significant (p=0.178, p=0.296; respectively). None of the above mentioned cytokine levels changed significantly as a result of SIT. Conclusion. The results of our study indicate that although clinical findings improve after one year of SIT, this duration may not be sufficient to detect changes in cytokine patterns and transcription factors. Further studies that evaluate outcome over a longer duration of treatment would provide valuable information.
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    Plants used as natural dye sources in Turkey
    Dogan, Y; Baslar, S; Mert, HH; Ay, G
    This study was carried out in the regions where handcrafts such as carpet and rug weaving are common in Turkey. In the regions where natural dyes are used, 123 plant species belonging to 50 families were identified as sources of natural dyes. In natural dye production, different parts of the plant or the whole aboveground plant is used. Ten different colors are gained from the plants. Sometimes the same color can be obtained from different plants. By mixing different plants, it is possible to produce various colors. We also identified more than 12 natural and more than eight chemical assistant substances (mordant) that are used in the regions to bind dye to fibers, to maintain the strongness and brightness of the colors, and to obtain various colors.
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    TRACE ELEMENT CONTENTS IN PLANTS GROWING AT MT. AKDAG, DENIZLI
    Kula, I; Yildiz, D; Dogan, Y; Ay, G; Baslar, S
    The present study was conducted to determine the current level of atmospheric heavy metal pollution in the Akdag Mountain of Denizli Province. The increase in industrial activities and human population and the high urbanization in Denizli and its environs have made it one of the rapid developing cities in the Western Anatolian part of Turkey. For this reason, Akdag Mountain of Denizli was chosen as the study area. Twenty nine different plants were selected to study their potential as biomonitors of trace elements such as Pb, Cd, Ni, Zn, Fe and Mn (mu g g(-1), dry weight). The samples were collected from two different altitudes of Akdag, a mountain overlooking at Denizli province. The concentrations of trace elements were determined by atomic absorption spectrometry. The mean concentrations determined at 1000 m altitude ranged from 0.329 to 0.487, 0.011 to 0.882, 0.241 to 0.714, 0.532 to 9.396, and 0.155 to 3.439 (mu g g(-1), dry weight), for Pb, Ni, Zn, Fe and Mn, respectively. At 1600 m altitude, the values ranged from 0.263 to 0.889, 0.092 to 0.600, 0.272 to 0.834, 1.130 to 8.021 and 0.076 to 0.508 (mu g g(-1), dry weight) for Pb, Ni, Zn, Fe and Mn, respectively. No Cd was detected at both altitudes. Statistical significance was determined by the independent sample t-test. In the independent sample t-test, comparisons were made in order to determine whether there were any differences between the averages of the herbaceous plants and woody plants.
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    DETERMINATION OF TRACE ELEMENTS IN THE PLANTS OF MT. BOZDAG, IZMIR, TURKEY
    Yildiz, D; Kula, I; Ay, G; Baslar, S; Dogan, Y
    The aim of this study was to determine the current level of atmospheric heavy metal content on the Bozdag Mountain of the Aegean Region, Turkey. Twenty nine different plants were selected to study their potential as biomonitors of trace elements such as Ni, Zn, Fe, Pb, Mn and Cd (mu g g(-1), dry weight). The samples were collected from two different altitudes of Mt. Bozdag. The concentrations of trace elements were determined by atomic absorption spectrometry. The mean concentrations determined at 1000 m altitude ranged from 0.025 to 1.609, 0.232 to 0.731, 0.578 to 5.983, 0.287 to 0.565 and 0.176 to 2.659 (mu g g(-1), dry weight), for Ni, Zn, Fe, Pb and Mn, respectively. At the altitude of 1600 m, the values ranged from 0.023 to 0.939, 0.258 to 1.254, 0.839 to 5.176, 0.301 to 1.341 and 0405 to 3.351 (mu g g(-1), dry weight) for Ni, Zn, Fe, Pb and Mn, respectively. No Cd was detected at either altitude. Statistical significance was determined by the independent sample t-test and comparisons were made in order to determine if there were any differences between the averages of herbaceous and woody plants.
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    A Study of Trace Element Contents in Plants Growing at Honaz Dagi-Denizli, Turkey
    Baslar, S; Kula, I; Dogan, Y; Yildiz, D; Ay, G
    Denizli is one of the rapidly developing states in the West Anatolian Region of Turkey Keeping this in view, 30 different plants were selected to study their potential as biomonitors of trace elements like Pb, Cd, Ni, Zn, Fe and Mn (mu g g(-1), dry weight). The samples were collected from two different altitudes of Honaz Dagi, a mauntain overlooking at state of Denizli. The concentrations of trace elements were determined by flame atomic absorption spectrometry (FAAS). The mean concentrations determined at 1000 in altitude ranged between 0.273 to 0.488, 0.099 to 0.488, 0.306 to 0.682, 1.017 to 3.744, and 0.148 to 0.674 (mu g g(-1), dry weight), of Pb, Ni, Zn, Fe and Mn, respectively. At 1600 in altitude, the values ranged between 0.225 to 0.534, 0.150 to 0.842, 0.234 to 0.905, 1.082 to 3.864 and 0.023 to 0.982 (mu g g(-1), dry weight) of Pb, Ni, Zn, Fe, Pb and Mn, respectively. No Cd was detected at both altitudes.
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    The use of wild edible plants in western and central Anatolia (turkey)
    Dogan, Y; Baslar, S; Ay, G; Mert, HH
    Dogan, Yunus (Dokuz Eylul University, Faculty of Education, Department of Biology, 35150, Buca-Izmir, Turkey; e-mail yunus.dogan@deu.edu.tr), Suleyman Baslar (Dokuz Eylul University, Faculty of Education, Department of Biology, 35150, Buca-Izmir, Turkey), Gungor Ay (Celal Bayar University, Faculty of Science-Art, Department of Biology, Muradiye-Manisa, Turkey), and Hasan Huseyin Mert (Dokuz Eylul University, Faculty of Education, Department of Biology, 35150, Buca-Izmir, Turkey). THE USE OF WILD EDIBLE PLANTS IN WESTERN AND CENTRAL ANATOLIA (TURKEY). Economic Botany 58(4):684-690, 2004. In this study, 121 wild edible plants used as food in Anatolia were surveyed to determine the plant parts used and their detailed preparation methods. The results of this study show that the plants may be boiled, fried in fat, and eaten raw or as rolled vegetables. They may also be consumed as pickles, fruits, sweets and spices, and drunk as cold and hot drinks. Thirty species (8 genera) were identified as belonging to the Lamiaceae family, 15 species (15 genera) belong to the Asteraceae family, 13 species (5 genera) belong to the Rosaceae family, 8 species (7 genera) belong to the Brassicaceae family, 6 species (3 genera) belong to the Orchidaceae family and 5 species (5 genera) belong to the Apiaceae family. The genera represented by the highest number of species in the study are as follows: Sideritis L. is represented by 13 species, Origanum L. by 7 species, Rubus L. by 5 species, Thymus L. by 4 species and Rumex L. by 4 species.