196 research outputs found
The Galena Objects from Neolithic Ulucak: The Earliest Metallic Finds in Western Turkey
No full textThe earliest metal finds in central and eastern Anatolia are small copper and malachite beads dating from the 9th millennium BC onwards. However, the presence of metallic finds in Neolithic contexts from western Anatolia are rarely known. An analysis of metallic finds from Ulucak Hoyuk shows that galena was used at the site from the early 7th millennium BC to the early 6th millennium BC. Objects made of galena from initial phases at the site are considered personal ornaments, while an increasing number of galena lumps in relation to ovens were found in later phases. Thus, galena finds from Ulucak Heorik suggest that at first this raw material seemed to have been perceived as an exotic stone, while a full understanding of its properties may have been developed later.Turkish Ministry of Culture and Tourism; Trakya University (TUBAP Project) [2017/220]; TUBITAK fellowship [1059B191802282]We thank the anonymous reviewers for their constructive comments. The Ulucak Hoyuk excavation is supported by the Turkish Ministry of Culture and Tourism. The analyses of metallic finds from Ulucak Hoyuk were funded by Trakya University (TUBAP Project no: 2017/220). The work of Ozlem Cevik for the preparation of this article was also supported by TUBITAK fellowship (1059B191802282) which allowed a study period at La Sapienza University in Rome. We wish to thank Jarrad W. Paul for his kind corrections to the language in this paper
Characterization of protein-flavor interactions using inverse gas chromatography
No full textIn this research, we investigated the retention/release mechanism of selected flavor compounds on or from protein matrices by establishing quantitative design principles for these interactions. Thermodynamic parameters (partition coefficient Kp, free energy of adsorption ∆Gs and the enthalpy of adsorption ∆Hs) of the interaction between selected flavor compounds (hexane, hexanal, hexanol and d-limonene) and protein systems (soy protein isolate and zein) were determined by using inverse gas chromatography under different temperatures and relatively humid conditions. The inverse gas chromatography system was fitted with an additional humidification system that could maintain the relative humidity of the carrier gas, thus enabling the evaluation of the effect of relative humidity on the measured quantities. Increasing temperature and relative humidity led to less favorable interaction between selected flavors and proteins. Flavor retention at high relative humidity was less than at low relative humidity or at dry conditions. This suggests that flavor compounds and water molecules might be competing to bind to the available sides of the protein. Quantitative characterization of the mechanism and thermodynamics of flavor binding and release in protein matrices will benefit the food industry to efficiently develop flavored foods.M.S.Includes bibliographical referencesby Ozlem Dol
Use of Multivariate Statistics Methods to Determine Grain Size, Heavy Metal Distribution and Origins of Heavy Metals in Mersin Bay (Eastern Mediterranean) Coastal Sediments
No full textThe aim of the study was to determine variability, heavy Metal Content and potential origins of heavy metals of the sediments in a total of 60 locations representing coastal sediments of Mersin Bay,Grain size distribution and heavy metal contents were measured and multivariate statistical analyses were performed on obtained Values in grain size distribution, Oz-4, 5, 6, 11, 12, 13, 14, 15, 16, 18, 19, 22 23, 46, 48, 49, 50 Stations showed a bimodal distribution. This distribution developed due to river networks near the locations. Heavy metals are sequenced as Cr, Mn, Sr, Ni, V, Zn, Co, Zr, Rb, Ce, Cu, Sc, Li, Y, Pb, As, Nb, Mg, Fe, Al, Th and U from the higher value to the lower value according to their abundance: According to frequency histogram, Ni, Fe, Al, which showed the highest concentration values among heavy metals came from short medium distance; while Cr, Ti and Mn came from short distance. Based on these findings it should be thought,that heavy Metal sources affecting Study area are in short distances to study area All the elements were represented with three sector principal component analysis. Total variances of Pb, As, U, Th, Sb, P, La, Ba, Na, K, W, Ce, Li and Rb elements which represent (F1) factor were explained by 30.591 %. Variance of Mn, Fe, V, Ti, Al, Zr, Y, Sc and Hf elements which represent (F2) factor were explained by 18.749'%. Total Variance of Mo, U, Sr, Ca, P, Ti, Nb and Ta elements which represent the third factor (F3) were explained by 14.512 %. These data are significantly consistent with the dendongram prepared according to coefitic correlation coefficients. Hierarchical group analysis dendorigram showed that Q-type cluster had a 50 % arbitrary Similarity level and that contamination generally occurred in group 3. It can be thought that similar groups had the same properties during contamination. In regression data performed according to Fe; "Model summary" (according to R-2 = 99.8 value) was Significantly adequate for Statistical data and "Anova". was highly reliable with 36 explanatory Variables. Heavy metals in the study area such as Cr, Mn, Ni, Zn, Co, Cu, Pb, Mg, Al, Cd, Sb and Ti might show toxic effects. Heavy metals, such as As, Ag, Fe, Mo And Sn should also be paid attention. Al, Fe, Ti, Mn, Cr, Ni, Co, Pb, Zn and V showed an anomaly according to Kizkalesi and Susanoglu coastal sand. Cr, Ni, Co, Mg, Ti, Fe and Mn increased due to Mersin Ophiolite. The areas where basie/ultrabasic rocks outcropped in the region can be considered as the source of natural contaminations. Anthropogenic factors, coastal sediments, coastal erosion and lithological effects are the main causes of contamination in the study area, which covers a very wide area. In addition, the port, river entrances, highway, urban wastes, tourist facilities and industrial sites increased the density of anthropogenic effect.Scientific Research Projects Unit of Akdeniz UniversityThis study contains a part of Master of Science thesis and Scientific Research Projects of Nigde University prepared by Ozlem CEVIK. The financial support of the Scientific Research Projects Unit of Akdeniz University is gratefully acknowledged
Risk-averse control of undiscounted transient Markov models
No full textThe classical optimal control problems for discrete-time, transient Markov processes are infinite horizon, undiscounted expected total cost or reward models. Some examples of these models are optimal stopping problems and stochastic shortest or longest path problems, which may have applications in health-care, finance, and maintenance. However, such expected value models implicitly assume the decision maker is risk-neutral, so they may not be appropriate for several real-life problems. In this study, we use Markov risk measures to formulate a risk-averse version of the optimal control problem for transient Markov processes with general state and compact control spaces. We derive risk-averse dynamic programming equations and show that they have a unique solution which is also the optimal value of the Markov control problem. Furthermore, it is shown that a randomized policy may be strictly better than deterministic policies, when risk measures are employed. We suggest two algorithms, value iteration and policy iteration methods, for solving the dynamic programming equations and show their convergence. In general, each policy evaluation step of the policy iteration algorithm requires solving a system of nonsmooth equations. We use a version of nonsmooth Newton method to solve these equations and show its global convergence. We further consider a risk-averse finite horizon Markov control problem under randomized policies and derive a value iteration method for its solution. Finally, we work on asset selling, organ transplant, and credit card examples to illustrate the theory for infinite horizon problem, and present numerical results.Ph. D.Includes bibliographical referencesIncludes vitaby Ozlem Cavu
Modeling traveler behavior via day-to-day learning dynamics
No full textTravel behavior lies at the core of analysis and evaluation of transportation related measures aiming to improve urban mobility, environmental quality and a wide variety of social objectives. A better understanding of travel behavior will improve travel demand forecasting and the assessment of emerging transport policies, and will improve our means to increase road safety. The day-to-day models reflect the travelers’ learning and forecasting mechanisms. These models predict travelers’ choices for any given day based on their experienced choices in the previous days. Day-to-day approaches allow the use of wide range of behavioral rules, and levels of aggregation, and capture the heterogeneity in users’ learning and adaptation processes, and behavioral characteristics. This thesis aims to develop a novel framework to model the interdependence between travelers’ choice decisions, learning and adaptation behavior and the day-to-day update mechanism of traffic flows. The novelty of this thesis is that the proposed approach combines traveler heterogeneity and rationality in a single framework to predict travelers’ day-to-day departure time and route decisions, and develops a novel day-to-day dynamic traffic assignment approach. The empirical results obtained from real transportation network, New Jersey Turnpike, confirm that the proposed day-to-day learning and dynamic traffic assignment framework model can successfully capture the significant learning dynamics, demonstrating the possibility of developing a psychological framework (i.e., learning models) as a viable approach to represent travel behavior. The other contributions of this thesis include a novel route choice set generation approach based on stochastic integer programming approach. The proposed methodology takes into account travel time variability and reliability in the transportation network. The path relevance criteria are directly incorporated into the optimization model by minimizing mean travel time, travel time variability and path overlap. Unlike previous approaches in the literature, proposed methodology eliminates the filtering step from the choice set generation and generates paths sets at desired dissimilarity level while minimizing the travel time and variability of these paths. Several case studies show the applicability of the proposed methodology on real transportation networks.Ph.D.Includes bibliographical referencesIncludes vitaby Ozlem Yanmaz-Tuze
Synthesis of Diflunisal Thiazolidinones as Anticancer Agents
No full textA series of diflunisal 4-thiazolidinones were synthesized. Some selected compounds were determined at one dose towards the full panel of 60 human cancer cell lines by National Cancer Institute. 2',4'-Difluoro-4-hydroxy-N-[4-oxo-2-(thiophen-2-yl)-1,3-thiazolidin-3-yl]biphenyl-3-carboxamide (4a) demonstrated the most marked effect on K-562 cancer cell line with 58.59 % growth inhibition at 10 mu M. Compound 4a was evaluated in vitro using the MTT colorimetric method against human leukemia cell line K-562 and mouse embryonic fibroblasts cell line NIH-3T3 at different doses for cell viability and growth inhibition. Compound 4a exhibited anticancer activity with IC50 value of 5.2 mu M against K-562 cells and did not display cytotoxicity towards NIH-3T3 cells compared with diflunisal. In addition, this compound could be an interesting prototype as an antiproliferative agent
The Protective Effects Of<i> Momordica</I><i> Charantia</I> Fruit Extract in Methotrexate Induced Liver Damage in Rats
No full texterdogan, omer/0000-0002-8327-7077; Sen, Ali/0000-0002-2144-5741; Cevik, Ozge/0000-0002-9325-3757; Ede-Pazarbasi, Seren/0000-0002-3195-4064; Cilingir-Kaya, Ozlem Tugce/0000-0002-2591-9174; Sener, Goksel/0000-0001-7444-6193; Ozbeyli, Dilek/0000-0002-4141-6913BACKGROUND/AIMS: Methotrexate (MTX), a cytotoxic therapeutic agent, is used for the cure of malignancies and rheumatologic disorders. However, the significant side effects of MTX limits its use. In this study, we aim to assess the hepatoprotective properties of Momordica charantia (MC) against MTX-induced liver damaged in rats.MATERIALS AND METHODS: Following one dose of MTX (20 mg/kg), the rats were given either distilled water or MC extract (300 mg/kg, po) for 5 days. After the dissection of the rats, the liver was removed to analyse tumour necrosis factor -a (TNF-a), interleukin-113 (IL-113), transforming growth factor 13 (TGF-13) and 8-hydroxy-2'-deoxy-guanosine (8-OhdG) levels and superoxide dismutase (SOD), catalase (CAT), and caspase-3 activities. The tissues were also examined histopathologically.RESULTS: The hepatic TNF-a, IL-113, TGF-13, 8-OhdG levels, and Caspase-3 activity in the MTX group were found to be significantly increased compared to the control group. However, MC extract was able to significantly decrease TNF-a, TGF-13, 8-OhdG levels, and Caspase-3 activity. Also, both the SOD and CAT activity of the MTX group decreased compared to the control group. Although only the SOD levels elevated significantly with MC treatment, the SOD and CAT activities of the MC treated group were similar to the control group. Supporting these biochemical parameters, MTX-induced histologic alterations in the liver were also ameliorated via MC treatment.CONCLUSION: Our results demonstrated that MC has a protective role against MTX-induced hepatic tissue injury by reducing apoptosis, oxidative damage, and the expression of pro-inflammatory cytokines.Emerging Sources Citation Inde
Etanercept protects myocutaneous flaps from ischaemia reperfusion injury: An experimental study in a rat tram flap model
No full textBackground Being an inevitable component of free tissue transfer, ischemia-reperfusion injury tends to contribute to flap failure. TNF- is an important proinflammatory cytokine and a prominent mediator of the ischemia-reperfusion injury. Etanercept, a soluble TNF- binding protein, has shown anti-inflammatory and anti-apoptotic effects in animal models of renal and myocardial ischemia-reperfusion injury. We have designed an experimental study to investigate the effect of etanercept on myocutaneous ischemia-reperfusion injury on transverse rectus abdominis myocutaneous flap model in rats.Methods Twenty-four male Sprague-Dawley rats were divided into 3 groups: In group 1 (sham), the TRAM flap was raised and sutured back without further intervention. In group 2 (control), the flap was raised and the ischemia-reperfusion protocol was followed. In group 3, etanercept (10 mg/kg, i.v.) was administered 10 minutes before reperfusion. At the end of the reperfusion period, biochemical and histolopathological evaluations were performed on serum and tissue samples.Results In the etanercept group the IMA and 8-OHdG levels (p=0.005 and p=0.004, respectively) were found significantly lower, and the GSH and SOD levels (p=0.01 and p<0.001, respectively) significantly higher in comparison to the control group. The histopathological analysis has revealed a lower degree of hyalinization, degenerated muscle fibers and nuclear change in the etanercept group compared to the control group.Conclusion The results of our experimental study indicate that etanercept offers protection against ischemia-reperfusion injury in skeletal muscle tissue, enhancing the TRAM flap viability. The ability of etanercept to induce ischemic tolerance suggests that it may be applicable in free-flap surgery
Corrigendum to “The status of depression and anxiety in infertile Turkish couples” [Iran J Reprod Med 2011; 9: 99-104]
No full textThe publisher has been informed of an error that occurred on page 99 in which the second authors name must be changed to Ozlem Kayacik Gunday. On behalf of the author, the publisher wishes to apologize for this error. The online version of article has been updated on 31 August 2023 and can be found at https://doi.org/10.18502/ijrm.v9i2.104
The safety and effectiveness of 0.16 mg bevacizumab plus or minus additional laser photocoagulation in the treatment of retinopathy of prematurity
No full textPurpose: Retinopathy of prematurity (ROP) is the leading cause of preventable blindness in premature infants. Antivascular endothelial growth factor (anti-VEGF) therapy has been used increasingly in treatment as a pharmacological alternative to laser therapy. In this study, we evaluate the results of low-dose anti-VEGF treatments. Methods: Design: Retrospective--observational study. Infants who had been evaluated for ROP disease between February 2016 and February 2017 were assessed. We retrospectively reviewed the ROP stages, treatment results, and complications. Laser photocoagulation (LPC) and intravitreal bevacizumab (0.16 mg IVB) were used for treatment and fundus fluorescein angiography (FFA) was also performed in some of the cases. Results: IVB was applied to 43 infants. A macular hole was seen in one infant's eye after IVB. LPC was applied to avascular areas in 21 infants. In three patients, persistence of the disease was observed after administration of a low dose of IVB. Additional LFK was performed in these patients. None of the infants who received LPC had any complications. Conclusion: IVB is increasingly becoming the first-line treatment for ROP. For severe ROP, 0.16 mg IVB is effective. Using LPC to treat avascular areas after 70 weeks' gestational age (GA) may decrease the risk of late recurrence and appears to be a safe treatment to use
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