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Publication Open Access Trace Elements in the Soil-Plant Systems of Copper Mine Areas-A Case Study From Murgul Copper Mine From the Black Sea Region of Turkey(TECH SCIENCE PRESS, 2019) Ozturk, Munir; Altay, Volkan; Kucuk, Mahir; Yalcin, Ibrahim Ertugrul; Ege University; Ege University; Hatay Mustafa Kemal University; Bahcesehir UniversityThis study presents a case study on the heavy metal analysis of soil and plant samples around the Murgul copper mine, one of the first and most important mining areas in Turkey. An attempt has been made to investigate the status of trace elements like Al3+, Fe2+, Cu2+, Zn2+, Pb2+, Ni2+, Co2+ and Cd2+ in soils and plants. The sampling localities were taken from 500 m, 600 m, and 1000 m altitudes around the factory and at 1400 m in the forest zone. The aboveground parts and foliage ash of Silene compacta, Tussilago farfara, Smilax excelsa, Rhododendron ponticum, R. luteum, and herbal mix were analysed. The results of analysis have revealed the minimum and maximum concentrations measured in the plants as follows, aluminium (20-8985 mg kg(-1)), cadmium (0.0-0.5 mg kg(-1)), cobalt (0.0-5.5 mg kg(-1)), copper (0.0-347.5 mg kg(-1)), iron (25-9320 mg kg(-1)), lead (2-51 mg kg(-1)), nickel (1.5-16.5 mg kg(-1)), and zinc (13.0-221.0 mg kg(-1)). In the soil the concentrations of aluminium, cadmium, cobalt, copper, iron, lead, nickel, and zinc vary between 33-457, 0.0-0.0, 0.0-0.4, 0.1-88.7, 14-50, 0.3-4.1, 0.2-0.8, and 4.0-20.3 mg kg(-1) respectively. These findings enlighten the fact that copper is generally toxic in the soils as well as plants. Silene compacta has been recorded as a high copper accumulator, behaving as a healthy plant on the polluted sites of the area alongside the Murgul creek (especially at 600 m). This study stresses the fact that it is imperative to assess and monitor the levels of heavy metals in the environment due to anthropogenic activities, including mining, for evaluation of human exposure and for sustainable environment.Publication Metadata only Cognitive Backgrounds of Problem Solving: A Comparison of Open-ended vs. Closed Mathematics Problems(MODESTUM LTD, 2015) Bahar, Abdulkadir; Maker, C. June; Bahcesehir University; University of ArizonaProblem solving has been a core theme in education for several decades. Educators and policy makers agree on the importance of the role of problem solving skills for school and real life success. A primary purpose of this study was to investigate the influence of cognitive abilities on mathematical problem solving performance of elementary students. The author investigated this relationship by separating performance in open-ended and closed situations. Findings of the study indicated that the cognitive abilities explained 32.3% (open-ended) and 48.2% (closed) of the variance in mathematical problem solving performance as a whole. Mathematical knowledge and general intelligence were found to be the only variables that contributed significant variance to closed problem solving performance. General creativity and verbal ability were found to be the only variables that contributed significant variance to open-ended problem solving performance.Publication Open Access Popular Culture: From Being an Enemy of the Feminist Movement to a Tool for Women's Liberation?(John Wiley and Sons Inc, 1999) Kirca, Süheyla; Kirca, Süheyla, Public Relations Department, Bahçeşehir Üniversitesi, Istanbul, Turkey[No abstract available]Publication Open Access House mice with metacentric chromosomes in the Middle East(Mendelian Society of Lund, 2000) Gündüz, Islam; Tez, Cosslkun; Searle, Jeremy B.; Gündüz, Islam, Department of Biology, Bahçeşehir Üniversitesi, Istanbul, Turkey; Tez, Cosslkun, Department of Biology, Erciyes Üniversitesi, Kayseri, Turkey; Searle, Jeremy B., Department of Biology, University of York, York, United Kingdom[No abstract available]Publication Open Access The synthesis of novel crown ethers, part VII [1]. Coumarin derivatives of benzocrowns and cation binding from fluorescence spectra(Springer Netherlands, 2000) Erk, Çakil L.; Bulut, Mustafa; Göçen, Ayten; Erk, Çakil L., Department of Chemistry, İstanbul Teknik Üniversitesi, Istanbul, Turkey; Bulut, Mustafa, Department of Chemistry, Marmara Üniversitesi, Istanbul, Turkey; Göçen, Ayten, Department of Chemistry, Bahçeşehir Üniversitesi, Istanbul, Turkey4-[3-(1-benzopyran-2-one)] derivatives of benzo[12]crown-4, benzo[15]crown-5 and benzo-[18]crown-6 were synthesized from 4-[3-(1-benzopyran-2-one)]-1,2-dihydroxy-benzene reacting with bis-ethyleneglycol dihalides or pentaethylene glycol ditosylate in alkali carbonate/DMF/water. The original products were identified by high resolution EI-mass spectra as well us IR, 1H-NMR and 13C-NMR spectroscopy. The 1 : 1 binding constants of Mg2+, Li+, Na+ and K+ with the coumarin-benzocrowns were estimated using fluorescence emission spectroscopy in acetonitrile. The complexing enhanced quenching fluorescence spectra (CEQFS) and complexing enhanced fluorescence spectra (CEFS) exhibited the ion binding powers due to cationic recognition rules of the macrocycles. © 2020 Elsevier B.V., All rights reserved.Publication Open Access Fluorine determination in human and animal bones by particle-induced gamma-ray emission(Springer Verlag, 2001) Sastri, Chaturvedula S.; Lyengar, Venkatesh; Blondiaux, Gilbert B.; Tessier, Yves; Petri, Hermann; Hoffmann, Peter S.; Aras, Namık K.; Zaichick, Vladimir Ye; Ortner, Hugo Manfred; Sastri, Chaturvedula S., Fachbereich Material- und Geowissenschaften, Technische Universität Darmstadt, Darmstadt, Germany; Lyengar, Venkatesh, International Atomic Energy Agency, Vienna, Vienna, Austria; Blondiaux, Gilbert B., Centre de Recherches Internationales Sciences Po, Paris, France; Tessier, Yves, Centre de Recherches Internationales Sciences Po, Paris, France; Petri, Hermann, Forschungszentrum Jülich GmbH, Julich, Germany; Hoffmann, Peter S., Fachbereich Material- und Geowissenschaften, Technische Universität Darmstadt, Darmstadt, Germany; Aras, Namik K., Department of Chemistry, Middle East Technical University (METU), Ankara, Turkey, Bahçeşehir Üniversitesi, Istanbul, Turkey; Zaichick, Vladimir Ye, A. Tsyb Medical Radiological Research Center, Obninsk, Russian Federation; Ortner, Hugo Manfred, Fachbereich Material- und Geowissenschaften, Technische Universität Darmstadt, Darmstadt, GermanyFluorine was determined in the iliac crest bones of patients and in ribs collected from post-mortem investigations by particle-induced gamma-ray emission based on the 19F(p,p′y)19F reaction, using 2.0/2.5 MeV protons. The results indicate that for 68% of the human samples the F concentration is in the range 500-1999 μg g-1. For comparison purposes fluorine was also determined in some animal bones, in some animal tissues lateral profiles of fluorine were measured. © Springer-Verlag 2001. © 2020 Elsevier B.V., All rights reserved.Publication Open Access Substrate specificity, heat inactivation and inhibition of polyphenol oxidase from different aubergine cultivars(2002) Doǧan, Mehmet; Arslan, Oktay; Doǧan, Serap D.; Doǧan, Mehmet, Department of Chemistry, Bahçeşehir Üniversitesi, Istanbul, Turkey; Arslan, Oktay, Department of Chemistry, Bahçeşehir Üniversitesi, Istanbul, Turkey; Doǧan, Serap D., Department of Biology, Bahçeşehir Üniversitesi, Istanbul, TurkeyThe effects of substrate specificity, heat inactivation, temperature, pH and inhibitors on polyphenol oxidase (PPO) activity obtained from three different aubergine cultivars were investigated to identify the most appropriate aubergine cultivar for dried preparations. PPO obtained from different aubergine cultivars (cultivars I, II and III) was partially purified by (NH4)2SO4 precipitation followed by dialysis. PPO showed activity with catechol and 4-methylcatechol but not with L-tyrosine. The best substrate for cultivar I (Vmax: 3333.3 EU min-1 mL-1, Km: 8.7 mM and Vmax/Km: 384.9 min-1) and cultivar III (Vmax: 1000 EU min-1 mL-1, Km: 9.3 mM and Vmax/Km: 107.5 min-1) was catechol, but 4-methylcatechol was the best substrate for cultivar II (Kmax: 5000 EU min-1 mL-1, Km: 35.5 mM and Vmax/Km: 140.8 min-1). The optimum pH for aubergine PPO was 7.0 with catechol as a substrate and 6.0 with 4-methylcatechol. Heat inactivation studies showed a decrease in enzyme activity at temperatures above 40 °C. For catechol and 4-methylcatechol substrates, the optimum temperature for maximum PPO activity was 30 °C for all aubergine cultivars except cultivar I using catechol which was 20 °C. The effects of compounds such as tropolone, D,L-dithiothreitrol and glutathione as inhibitors of the reactions catalysed by PPO were tested. Generally, tropolone was the most effective inhibitor. © 2011 Elsevier B.V., All rights reserved.Publication Open Access Cooling scheme based on the AF-F transition in Fe-Rh alloys induced by tensile stress(2002) Annaorazov, Murad P.; Nikitin, Sergey Aleksandrovich; Tyurin, A. L.; Akopyan, S. A.; Myndyev, R. W.; Annaorazov, Murad P., Faculty of Arts and Sciences, Bahçeşehir Üniversitesi, Istanbul, Turkey; Nikitin, Sergey Aleksandrovich, Department of Physics, Lomonosov Moscow State University, Moscow, Russian Federation; Tyurin, A. L., Department of Physics, Turkmen State University, Ashgabad, Turkmenistan; Akopyan, S. A., Department of Physics, Turkmen State University, Ashgabad, Turkmenistan; Myndyev, R. W., Department of Physics, Turkmen State University, Ashgabad, TurkmenistanA cooling scheme based on the first-order antiferromagnetism-ferromagnetism transition induced in the Fe-Rh alloy by one-dimensional tensile stress is proposed. Using the model S-T diagram for this alloy, the cooling cycles are drawn up based both on the latent heat of transition absorption and emission when the transition is induced isothermally and on the change in temperature of the alloy when the transition is induced adiabatically by applying tensile stress. The calculated values of the efficiency ε for the cycles are ∼35 at ΔT - 5 K and ∼27 at ΔT = 10 K, where ΔT is the difference between the temperature of the surroundings and that of the cooled body. These values are achieved using a tensile stress of ∼1 × 109 Pa. The high values of ε make it possible to consider Fe-Rh alloys near the equiatomic composition as an effective refrigerant for elastocaloric cooling near room temperature. © 2004 Elsevier Science B.V., Amsterdam. All rights reserved.Publication Open Access Global variations in peak bone mass as studied by dual-energy X-ray absorptiometry(Akademiai Kiado Rt., 2004) McCloskey, Eugene V.; Dey, Abhijit; Parr, Robert M.; Aras, Namik K.; Balogh, Ádám; Bostock, J.; Borelli, Aurélio; Krishnan, Sivarama S.; Lobo, Gerald J.; Qin, Linlin; McCloskey, Eugene V., Who Collaborating Centre for Metabolic Bone Diseases, Sheffield, United Kingdom; Dey, Abhijit, Who Collaborating Centre for Metabolic Bone Diseases, Sheffield, United Kingdom; Parr, Robert M., International Atomic Energy Agency, Vienna, Vienna, Austria; Aras, Namik K., Bahçeşehir Üniversitesi, Istanbul, Turkey; Balogh, Ádám, Debreceni Egyetem, Debrecen, Hungary; Bostock, J., Who Collaborating Centre for Metabolic Bone Diseases, Sheffield, United Kingdom; Borelli, Aurélio, Hospital das Clinicas, Sao Paulo, Brazil; Krishnan, Sivarama S., Toronto General Hospital, Toronto, Canada; Lobo, Gerald J., Clínica Indisa, Santiago, Chile; Qin, Linlin, China-Japan Friendship Hospital, Beijing, ChinaIn 1994, the International Atomic Energy Agency (IAEA) initiated a 5-year Co-ordinated Research Project (CRP) to determine geographical and racial differences in peak bone mineral density (BMD) in men and women aged 15-49 years. The study demonstrates that there are distinct global differences in BMD at the hip and spine in both men and women approximating to one population standard deviation between populations with the highest and lowest BMD. These differences persist following adjustments for age, sex and body size. Such information is valuable in understanding the reasons for global differences in fracture rate and predicting future trends in fracture incidence. © 2025 Elsevier B.V., All rights reserved.Publication Open Access Precision of a dual energy X-ray absorptiometry device(Akademiai Kiado Rt., 2004) Korkusuz, Feza; Işikh, S.; Akin, Sabire; Ungan, Mehmet; Şenköylü, Alpaslan; Aras, Namik K.; Korkusuz, Feza, Medical Center, Middle East Technical University (METU), Ankara, Turkey; Işikh, S., Medical Center, Middle East Technical University (METU), Ankara, Turkey; Akin, Sabire, Medical Center, Middle East Technical University (METU), Ankara, Turkey; Ungan, Mehmet, Medical Center, Middle East Technical University (METU), Ankara, Turkey; Şenköylü, Alpaslan, Medical Center, Middle East Technical University (METU), Ankara, Turkey; Aras, Namik K., Bahçeşehir Üniversitesi, Istanbul, TurkeyThe standard method to diagnose and follow-up osteoporosis is the measurement of bone mineral density (BMD) using dual X-ray absorptiometry (DEXA). Manufacturers' manuals of DEXA devices state the intrascanner coefficient of variance is less than 0.01 g/cm2. The aim of this study was to evaluate the in vivo coefficient of variance of a Lunar DPX scanner in male and female healthy adult subjects. Average BMD for females and males were 1.170±0.091 g/cm2 and 1.272±0.115 g/cm 2, respectively. Monthly phantom measurements provided and controlled by the manufacturer were 1.243±0.008 g/cm2 (range 1.222 to 1.257) and the coefficient of variance was 0.006. It is concluded that the in vivo coefficient of variance of DEXA devices can slightly be higher than that proposed by the manufacturer. © 2025 Elsevier B.V., All rights reserved.