ON A SEQUENCE OF KANTOROVICH TYPE OPERATORS VIA RIEMANN TYPE q-INTEGRAL

Bascanbaz-Tunca, Gulen,Erencin, Aysegul,Tasdelen, Fatma Korean Mathematical Society 2014 대한수학회보 Vol.51 No.2

In this work, we construct Kantorovich type generalization of a class of linear positive operators via Riemann type q-integral. We obtain estimations for the rate of convergence by means of modulus of continuity and the elements of Lipschitz class and also investigate weighted approximation properties.

ON A SEQUENCE OF KANTOROVICH TYPE OPERATORS VIA RIEMANN TYPE q-INTEGRAL

Gulen Bascanbaz-Tunca,Fatma Tasdelen,Aysegul Erencin 대한수학회 2014 대한수학회보 Vol.51 No.2

In this work, we construct Kantorovich type generalization of a class of linear positive operators via Riemann type q-integral. We obtain estimations for the rate of convergence by means of modulus of continuity and the elements of Lipschitz class and also investigate weighted approximation properties.

Can Bergmann’s Rule and the Thermal Melanism Hypothesis explain the variation in colour and size observed in the wild bee Eoanthidium insulare (Apoidea: Megachilidae) across its Palaearctic range?

Kasparek Max,Ivgin Tunca Rahşan,Özgül Okan 한국응용곤충학회 2024 Journal of Asia-Pacific Entomology Vol.27 No.1

To analyse geographic variation patterns and assess the applicability of biogeographical rules in insects, the West Palaearctic anthidiine bee Eoanthidium insulare serves as an excellent model. This species showcases a highly variable black-and-yellow colour pattern, with a distribution spanning over 4400 km from the Adriatic Sea to the Pamir Mountains and extending over 1660 km in a south-north direction. We examined 214 specimens from all geographic regions of its distribution and identified a significant increase in both body size and the proportion of black in the integument from south to north. This phenomenon may be attributed to a more efficient exploitation of solar energy through a larger integument surface area (Bergmann’s Rule) and enhanced heat retention due to lower skin reflectance (Thermal Melanism Hypothesis). These two processes, therefore, complement each other. However, despite the cooler climates at higher altitudes, we found no correlations between body size and alti tude. Furthermore, while we observed an increase in the proportion of black in the integument from east to west, there was no significant increase in body size. Notably, no correlation between body size and body colouration was identified, suggesting that size and colour adaptation are independent processes. Given that the various colour and size patterns were identified as clinal rather than discontinuous, and the intraspecific genetic distance across the distribution area was remarkably low (0.00138), featuring only four distinct haplotypes of the mitochondrial COI region DNA sequence, we suggest that the subspecies E. i. persicolum and E. i. lemesium be regarded as synonymous with the nominate subspecies (syn. nov.). These findings suggest that, although Berg mann’s Rule and the Thermal Melanism Hypothesis can account for certain aspects of geographic variation in the body size and colouration of E. insulare, their effects may be influenced or superimposed by factors such as genetic constitution.

Experimental investigation and numerical analysis of optimally designed composite beams with corrugated steel webs

Ferhat Erdal,Osman Tunca,Ramazan Ozcelik 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.37 No.1

Composite beams with corrugated steel webs represent a new innovative system which has emerged in the past decade for medium span in the construction technology. The use of composite beams with corrugated steel webs results in a range of benefits, including flexible spaces and reduced foundation costs in the construction technology. The thin corrugated web affords a significant weight reduction of these beams, compared with hot-rolled or welded ones. In the current research, an optimal designed I-girder beam with corrugated web has been proposed to improve the structural performance of continuous composite girder under bending moment. The experimental program has been conducted for six simply supported composite beams with different loading conditions. The tested specimens are designed by using one of the stochastic techniques called hunting search algorithm. In the optimization process, besides the thickness of concrete slab and studs, corrugated web properties are considered as design variables. The design constraints are respectively implemented from Eurocode 3, BS-8110 and DIN 18-800 Teil-1. The last part of the study focuses on performing a numerical study on composite beams by utilizing finite element analysis and the bending behavior of steel girders with corrugated webs experimentally and numerically verified the results. A nonlinear analysis was carried out using the finite element software ANSYS on the composite beams which were modelled using the elements ten-node high order quadrilateral type.

Influence of trapezoidal and sinusoidal corrugation on the flexural capacity of optimally designed thin-walled beams

Ferhat Erdal,Osman Tunca,Harun Taylan,Ramazan Ozcelik,Huseyin Sogut 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.84 No.1

Major engineering requirements and technological developments in the steel construction industry are discussed to support a new innovative system, namely corrugated web beams, for future structural projections. These new-generation steel beams, fabricated as welded plate girders with corrugated webs, are designed to combine large spans with very low weight. In the present study, the flexural capacity of optimally designed trapezoidal and sinusoidal corrugated web beams was aimed at. For this purpose, the new metaheuristic methods, specifically hunting search and firefly algorithms, were used for the minimum weight design of both beams according to the rules of Eurocode EN 1193 15 and DASt-Ri 015. In addition, the strengthening effects of the corrugation geometry at the web posts on the load capacity of fabricated steel beams were tested in a reaction frame. The experimental tests displayed that the lateral capacity of trapezoidal web beams is more durable under flexural loads compared to sinusoidal web beams. These thin-walled beams were also simulated using a 3-D finite element model with plane strain to validate test results and describe the effectiveness of the ABAQUS software.

Letters to the Editor : Henoch-Sch?nlein Purpura during Isotretinoin Therapy

( Yilmaz Turan ),( Mutlu Cayirli ),( Mustafa Tunca ) 대한피부과학회 2013 Annals of Dermatology Vol.25 No.1

Protective effects of silymarin on fumonisin B1-induced hepatotoxicity in mice

Mahmut Sozmen,Alparslan Kadir Devrim,Recai Tunca,Murat Bayezit,Serpil Dag,Dinc Essiz 대한수의학회 2014 Journal of Veterinary Science Vol.15 No.1

The present study was conducted to investigate the effect ofsilymarin on experimental liver toxication induced byFumonisin B1 (FB1) in BALB/c mice. The mice were dividedinto six groups (n = 15). Group 1 served as the control. Group2 was the silymarin control (100 mg/kg by gavage). Groups 3and 4 were treated with FB1 (Group 3, 1.5 mg/kg FB1,intraperitoneally; and Group 4, 4.5 mg/kg FB1). Group 5received FB1 (1.5 mg/kg) and silymarin (100 mg/kg), andGroup 6 was given a higher dose of FB1 (4.5 mg/kg FB1) withsilymarin (100 mg/kg). Silymarin treatment significantlydecreased (p < 0.0001) the apoptotic rate. FB1 administrationsignificantly increased (p < 0.0001) proliferating cell nuclearantigen and Ki-67 expression. Furthermore, FB1 elevated thelevels of caspase-8 and tumor necrosis factor-alpha mediatorswhile silymarin significantly reduced (p < 0.0001) theexpression of these factors. Vascular endothelial growthfactor (VEGF) and fibroblast growth factor-2 (FGF-2)expressions were significantly elevated in Group 4 (p <0.0001). Silymarin administration alleviated increased VEGFand FGF-2 expression levels (p < 0.0001). In conclusion,silymarin ameliorated toxic liver damage caused by FB1 inBALB/c mice.

Is craniocaudal dissection of recurrent laryngeal nerve safer than lateral approach: a prospective randomized study comparing both techniques by using continuous intraoperative nerve monitoring

Yalin Iscan,Nurcihan Aygun,Ismail Cem Sormaz,Fatih Tunca,Mehmet Uludag,Yasemin Giles Senyure 대한외과학회 2022 Annals of Surgical Treatment and Research(ASRT) Vol.103 No.4

Purpose: This study was performed to compare the real-time electromyographic (EMG) changes and the rate of recurrent laryngeal nerve (RLN) injury in craniocaudal and lateral approaches for RLN during thyroidectomy. Methods: One hundred twelve and 86 patients were prospectively randomized to receive lateral (group 1) or craniocaudal (group 2) approach to RLN, respectively, under continuous intraoperative nerve monitoring. Results: Loss of signal (LOS) occurred in 7 (2.0%) of 356 nerves at risk (NAR). LOS was significantly associated with repeated adverse EMG changes and presence of RLN entrapment at the ligament of Berry (LOB), which was accompanied by other clinicopathological or anatomical features, such as tubercle of Zuckerkandl (TZ), extralaryngeal branching, hyperthyroidism, autoimmune thyroid disease (ATD), or thyroid lobe volume of >29 cm3 (P = 0.001 and P = 0.030, respectively). The rate of repeated adverse EMG changes and LOS in the NARs with LOB entrapment accompanied by other clinicopathological and anatomical features was higher in group 1 vs. group 2 (11.1% vs. 2.2%, respectively and 9.7% vs. 0%, respectively; P = 0.070). The total rate of vocal cord palsy (VCP) was significantly higher in group 1 than in group 2 (P = 0.005). The rate of permanent VCP showed no significant difference between the 2 groups. Conclusion: The craniocaudal approach to the RLN is safer than the lateral approach in the RLNs with entrapment at the LOB accompanied by other features, such as TZ, extralaryngeal branching, hyperthyroidism, ATD, or high thyroid lobe volume.

Determination of Serum Vascular Endothelial Growth Factor Levels in Attention Deficit Hyperactivity Disorder: A Case Control Study

Yasemin Taş Torun,Esra Güney,Arzu Aral,Dicle Büyüktaşkin,Hüseyin Tunca,Yasemen Işik Taner,Elvan İşeri 대한정신약물학회 2019 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.17 No.4

Objective: The effect of vascular endothelial growth factor (VEGF) on neuronal development is known, but its relationship with attention deficit hyperactivity disorder (ADHD), a neurodevelopmental disorder, has not yet been fully elucidated. To our knowledge, this is the first human study investigating serum VEGF levels in ADHD patients. In this study, it has been aimed to compare serum VEGF levels between a healthy control group and in ADHD patients to help determine the association between serum VEGF levels and ADHD. Methods: This study sample included forty-four patients diagnosed with ADHD and 43 healthy volunteer controls between 7 to 14 years old. Blood samples were taken from patients and the healthy control group to assess their serum VEGF levels. VEGF levels were calculated by subjecting the optical densities of the samples to concentrations of known standards as provided in the ELISA kit and then performing a regression correlation analysis. Results: The mean VEGF level of the children was 333.6 ± 209.8 in the ADHD group and 341.3 ± 201.8 in the control group. There were no statistically significant differences in serum VEGF levels between the ADHD and control groups (U = 926.000, z = −0.170, p = 0.865). Conclusion: There was no significant difference in serum VEGF levels for untreated ADHD cases and a healthy control group. This is the first human study investigating serum VEGF levels in ADHD patients, so there is a need to replicate these findings.

Effects of EGFR, CK19, CK20 and Survinin Gene Expression on Radiotherapy Results in Patients with Locally Advanced Head and Neck Cancer

Kekilli, Kezban Esra,Abakay, Candan Demioz,Tezcan, Gulcin,Tunca, Berrin,Egeli, Unal,Saraydaroglu, Ozlem,Esbah, Onur,Ekinci, Ahmet Siyar,Arslan, Sonay,Uslu, Nuri,Ozkan, Lutfi Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.7

Purpose: To investigate the effects of epidermal growth factor receptor (EGFR), cytokeratin 19 (CK19), cytokeratin 20 (CK20) and survinin gene expression on local control (LC) and overall survival (OS) in patients with locally advanced head and neck cancer (LAHNC) who were administered radiotherapy (RT). Materials and Methods: Twenty-six patients who were admitted to Uludag University Medical Faculty Department of Radiation Oncology with a diagnosis of LAHNC (GIII-GIV) were included in this study. Gene expression was evaluated in tumor tissues and peripheral blood. RNA isolation was performed on paraffinized tumor tissues and peripheral blood samples obtained before RT (BR). The densities of the obtained RNAs were analyzed at 260/280 nm. cDNA samples obtained from total RNA,EGFR, CK19, CK20 and survinin gene expression levels were assessed via the Sybr Green method and data were analyzed with the ${\Delta}{\Delta}Ct$ method. The same process was repeated for peripheral blood samples taken after RT (AR). Results: The female/male ratio was 3:23 and the mean age was 56.5 years (38-75years). After radiotherapy, CK19 and CK20 levels in the peripheral blood were found to be correlated according to Pearson correlation analysis(p=0.049). This result indicates a possibility of remaining positive for CK19 and CK20 in the peripheral blood even after RT in patients with CK19, CK20, and EGFR positive tumors before RT. There was a statistically significant correlation between survinin levels measured BR and AR (p=0.028). Conclusions: In this study, we found that patients with any EGFR, CK19, CK20 or survinin positivity in their peripheral blood obtain less benefit from radiotherapy. A wider patient population and advanced protein analyses are necessary in order to increase the reliability of our findings.