106 research outputs found
Comparing clusterings and numbers of clusters by aggregation of calibrated clustering validity indexes
No full textAkhanli, Serhat Emre/0000-0001-7173-3277WOS: 000543319300001A key issue in cluster analysis is the choice of an appropriate clustering method and the determination of the best number of clusters. Different clusterings are optimal on the same data set according to different criteria, and the choice of such criteria depends on the context and aim of clustering. Therefore, researchers need to consider what data analytic characteristics the clusters they are aiming at are supposed to have, among others within-cluster homogeneity, between-clusters separation, and stability. Here, a set of internal clustering validity indexes measuring different aspects of clustering quality is proposed, including some indexes from the literature. Users can choose the indexes that are relevant in the application at hand. In order to measure the overall quality of a clustering (for comparing clusterings from different methods and/or different numbers of clusters), the index values are calibrated for aggregation. Calibration is relative to a set of random clusterings on the same data. Two specific aggregated indexes are proposed and compared with existing indexes on simulated and real data.EPSRCEngineering & Physical Sciences Research Council (EPSRC) [EP/K033972/1]The work of the second author was supported by EPSRC grant EP/K033972/1
Classification of juvenile myoclonic epilepsy data acquired through scanning electromyography with machine learning algorithms
No full textOsman, Onur (Arel Author), Özekes, Serhat (Arel Author)In this paper, classification of Juvenile Myoclonic Epilepsy (JME) patients and healthy volunteers included into Normal Control (NC) groups was established using Feed-Forward Neural Networks (NN), Support Vector Machines (SVM), Decision Trees (DT), and Na < ve Bayes (NB) methods by utilizing the data obtained through the scanning EMG method used in a clinical study. An experimental setup was built for this purpose. 105 motor units were measured. 44 of them belonged to JME group consisting of 9 patients and 61 of them belonged to NC group comprising ten healthy volunteers. k-fold cross validation was applied to train and test the models. ROC curves were drawn for k values of 4, 6, 8 and 10. 100% of detection sensitivity was obtained for DT, NN, and NB classification methods. The lowest FP number, which was obtained by NN, was 5
Political Endowments and Electricity Market Regulation in Turkey: An Institutional Analysis
No full textTurkey has been going through a liberalization process in its electricity market over the last decade. So far, the regulatory content of the market reforms has been in the center of attention in the literature, to the negligence of regulatory governance. However, recent studies, which applied the theoretical insights of new institutional economics to utilities regulation, have demonstrated that political endowments of the country draw the boundaries to which extent such regulatory content can be effectively implemented. In line with these studies, this paper adopts an institutional approach and attempts to identify the political endowments of Turkey in order to further analyze whether the market reforms succeeded in bringing about sufficient checks to cure the institutional problems. In other words, the paper takes a picture of the overall regulatory arena. The results show that the current regulatory structure, especially government-regulator relations, fails to meet good regulatory governance criteria. The paper also provides some policy suggestions.electricity regulation; regulatory governance; institutions
Psychiatric disorders and symptoms in children and adolescents with sleep bruxism
No full textThis study examines state-trait anxiety, anxiety sensitivity (AS), depressive symptom levels, and psychiatric disorders in children and adolescents with sleep bruxism (SB). Thirty-five patients (aged 8-17 years) with a diagnosis of SB and 35 healthy controls were included in the study. All participants were evaluated for psychiatric disorders using a structured clinical interview and completed self-report questionnaires. At least one psychiatric disorder was present in 42.9 % of the patient group and 17.1 % of the control group (p < 0.05). Trait and state anxiety, anxiety sensitivity, and the severity of depression symptoms were also higher in the SB group (p < 0.05). After the multivariate analysis, the associations between state and trait anxiety, depression, and SB became statistically insignificant, while the association with anxiety sensitivity persisted. This study suggests that SB is related to AS, regardless of the severity of anxiety or depressive symptoms
The effect of Pistacia terebinthus extract on lipid peroxidation, glutathione, protein, and some enzyme activities in tissues of rats undergoing oxidative stress
No full textThis study measures the effects of Pistacia terebinthus flower extract on the amounts of lipid peroxidation (LPO), total protein, glutathione, and enzyme activities in blood. It also measures the effects of the plant extract on glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) enzyme activities and it arrives at the conclusion that GSH-Px activity significantly increased in the Pistacia terebinthus-hydrogen peroxide group (P < 0.0001) and SOD activity meaningfully increased in the Pistacia terebinthus (P < 0.05) and Pistacia terebinthus-hydrogen peroxide (P < 0.0001) groups. It is also found that P. terebinthus extract has protective effects against LPO exerted in the kidney, brain, and lungs (P < 0.0001). The positive effects of P. terebinthus extract are also found on the levels of glutathione and total protein in all organs, except for the level of glutathione in the spleen and brain, and the increase of glutathione and total protein (P < 0.0001). These results are parallel to the effect of the extract used in this study on the LPO levels in tissues and they show that the plant species used in the study has positive effects on the activities of antioxidant molecules as well as protective effects against LPO
ANTIOXIDANT ACTIVITY, TOTAL PHENOLIC AND FLAVONOID CONTENT OF WATER AND ETHANOL EXTRACTS FROM ACHILLEA MILLEFOLIUM L
No full textAchillea millefolium (Asteraceae, civanperçemi) deri iltihaplanmaları, spazmodik ve gastrointestinal bozukluklar gibi çeşitli rahatsızlıklara karşı halk ilacı olarak kullanılmıştır. Bu çalışmada, etanol ve su ekstreleri A. millefolium çiçek, yaprak ve tohumlarından hazırlandı. Antioksidan aktivite, ferik tiyosiyanat metodu ve H2O2 radikal temizleme testleriyle ölçüldü ve A. millefolium ekstrelerinin fenolik bileşikleri ve flavonoit içerikleri saptandı. Sonuç olarak, A. millefolium çiçek, yaprak ve tohumları etkili H2O2 radikal temizleme aktivitesi ve lipid peroksidasyon inhibisyonu aktivitesi gösterdi ve bu antioksidan aktiviteler referans antioksidanlar BHA ve ?-tokoferol ile karşılaştırıldı.Achillea millefolium (Asteraceae, yarrow) has been used in folk medicine against several disturbances including skin inflammations, spasmodic and gastrointestinal disorders. In this study, ethanol and water extracts were prepared from A. millefolium flowers, leaves and seeds. Antioxidant activities were measured by ferric thiocyanate method, and H2O2radical scavenging activity assays and phenolic compounds and flavonoid contents of A. millefolium extracts were also determined. In conclusion, extracts of A. millefolium flowers, leaves and seeds had effective H2O2radical scavenging activity, total antioxidant activity, and these antioxidant activities were compared with BHA and ?tocopherol as reference antioxidant
Determination of Antioxidant Capacities of Phlomis pungens Wild. var. hispida Hub.-Mor.
No full textWOS: 000305033900091The genus Phlomis L. belongs to the Lamiaceae family and encompasses 100 species native to Turkey, North Africa, Europe and Asia. It is a popular herbal tea enjoyed for its taste and aroma. Phlomis species are used to treat various conditions such as diabetes, gastric ulcer, hemorrhoids, inflammation and wounds. In this study, ethanol and water extracts were prepared from powdered P pungens flowers and leaves. Antioxidant activities were measured by 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS(center dot+)) radical scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH center dot) scavenging, superoxide anion (02) radical scavenging, reducing activity and ferrous metal chelating activity assays. In conclusion, P. pungens flowers and leaves had effective ABTS(center dot+) and DPPH center dot radical scavenging, superoxide anion radical scavenging, reducing power and metal chelating activities when compared with BHA, BHT and alpha-tocopherol as reference antioxidants
Determination of Antioxidant Properties of Ethanol and Water Extracts of Achillea millefolium L. (Yarrow)
No full textAchillea millefolim L. is a member of the Asteraceae family that is commonly referred to as 'yarrow' and has been used in folk medicine against several disturbances including skin inflammations, spasmodic and gastrointestinal disorders, as well as hepato-biliary complaints. Ethanol and water extracts were prepared from powdered A. millefoliun flowers, leaves and seeds. In this study, antioxidant properties were studied by 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS(center dot+)) radical scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH(center dot)) scavenging, superoxide anion (O(2)(center dot-)) radical scavenging, reducing activity and ferrous metal chelating activity assays. In conclusion, A. millefolium flowers, leaves and seeds had effective ABTS(center dot+) and DPPH(center dot) radical scavenging, superoxide anion radical scavenging, reducing power and metal chelating activities. Additionally, these various antioxidant activities were compared with BHA, BHT and alpha-tocopherol as reference antioxidants
Reflections on methodology for assessing campus sustainability from a Turkish perspective
No full textAim: The author provides a critical reflection of the questionnaire discussed at the workshop “Methodology for assessing the campus sustainability from the perspective of multi-level antifragility” held on Friday 13 May at the WSB University in Wrocław. The author reflects from the background of his experience in Turkey. Design / Research methods: The author provides his own reflections and opinions, based on the discussions at the workshop. Conclusions / findings: It is very difficult to create a set of indicators making campus sustainability internationally comparable, as well as finding proper sources of information. A starting point in creating such indicators may be mistakes threatening organizational viability and external sustainability Originality / value of the article: The article provides critical feedback on an innovative approach towards research on campus sustainability. </jats:p
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