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Öğe An algorithm for computing digital cohomology groups(Natural Sciences Publishing Co., 2016) Demir E.Ü.; Karaca I.Several recent papers have discussed the digital version of the cohomology group for digital images, and some researchers calculate digital cohomology groups of some special two or three-dimensional digital images. In this paper, we determine the simplicial cohomology groups of some minimal simple closed curves and the digital surface MSS6. Also we give a general algorithm for computing digital cohomology groups of finite dimensional digital images. © 2016 NSP Natural Sciences Publishing Cor.Öğe Androgen-related hepatocellular tumor of the liver associated with Fanconi's anemia(2003) Aktaş S.; Apa H.; Diniz G.; Erbay A.; Ortaç R.; Vergin C.; Karaca I.; Elmas N.; Yüzer Y.Hepatocellular tumors are quite rare in pediatric age group. Its association with Fanconi's anemia and androgen therapy is well known but the pathogenesis is controversial. Occurrence of significant dysplasia causes great problems to differentiate it as hepatocellular adenoma or hepatocellular carcinoma. In this paper a 13 years old male case of hepatocellular tumor associated with Fanconi's anemia and androgen therapy is presented. He was given androgen and steroid therapy for 5 years and he had had hepatitis C virus infection for 3 years before the multifocal hepatic tumors were observed. Androgen therapy was witheld and surgery was performed twice. Patients taking androgenic-anabolic steroids should be carefully monitored with US and CT and tumor markers should be measured. The worrisome pathology that may occur in hepatic tumor in children particularly with androgen therapy does not necessarily predict malignant behaviour.Öğe The Arnon bases in the Steenrod algebra(De Gruyter Open Ltd, 2020) Turgay N.D.; Karaca I.Let 'œ = 'œ p {\mathcal{A}=\mathcal{A}_{p}} be the mod ⢠p {\mathrm{mod}\,p} Steenrod algebra, where p is a fixed prime and let 'œ ? {\mathcal{A}{\prime}} denote the Bockstein-free part of 'œ {\mathcal{A}} at odd primes. Being a connected graded Hopf algebra, 'œ {\mathcal{A}} has the canonical conjugation ?. Using this map, we introduce a relationship between the X- A nd Z-bases of 'œ ? {\mathcal{A}{\prime}}. We show that these bases restrict to give bases to the well-known sub-Hopf algebras 'œ ⢠(n-1) {\mathcal{A}(n-1)}, n ? 1 {n\geq 1}, of 'œ ? {\mathcal{A}{\prime}}. © 2020 Walter de Gruyter GmbH, Berlin/Boston 2020.Öğe The Arnon bases in the Steenrod algebra(De Gruyter, 2018) Turgay N.D.; Karaca I.Let = p {\mathcal{A}=\mathcal{A}-{p}} be the mod p {\mathrm{mod}\,p} Steenrod algebra, where p is a fixed prime and let ' {\mathcal{A}^{\prime}} denote the Bockstein-free part of {\mathcal{A}} at odd primes. Being a connected graded Hopf algebra, {\mathcal{A}} has the canonical conjugation ?. Using this map, we introduce a relationship between the X- and Z-bases of ' {\mathcal{A}^{\prime}}. We show that these bases restrict to give bases to the well-known sub-Hopf algebras ¢ (n - 1) {\mathcal{A}(n-1)}, n ? 1 {n\geq 1}, of ' {\mathcal{A}^{\prime}}. © 2018 Walter de Gruyter GmbH, Berlin/Boston 2018.Öğe Banach fixed point theorem for digital imagesa(International Scientific Research Publications, 2015) Ege O.; Karaca I.In this paper, we prove Banach fixed point theorem for digital images. We also give the proof of a theorem which is a generalization of the Banach contraction principle. Finally, we deal with an application of Banach fixed point theorem to image processing. © 2015 All rights reserved.Öğe Bilhemia, An unusual complication after blunt liver trauma in a child: Case report and review of the literature(2010) Turk E.; Temir Z.G.; Karkiner A.; Memis A.; Topalak O.; Evciler H.; Ucan B.; Karaca I.[No abstract available]Öğe The classification of digital covering spaces(2008) Boxer L.; Karaca I.In this paper we classify digital covering spaces using the conjugacy class corresponding to a digital covering space. © 2008 Springer Science+Business Media, LLC.Öğe Cohomological approach to reflexive graphs(Utilitas Mathematica Publishing Inc., 2019) Ege O.; Karaca I.In this paper, we construct a cohomology structure for reflexive graphs. We also prove the Universal coefficient theorem for singular cohomology in graphs. We show that the Kiinneth theorem doesn't yield for graphs. © 2019 Utilitas Mathematica Publishing Inc.. All rights reserved.Öğe Cohomology theory for digital images(2013) Ege O.; Karaca I.In this paper we propose a mathematical framework that can be used for dening cohomology of digital images. We state the Eilenberg-Steenrod axioms and the Universal Coefficient Theorem for this cohomology theory. We show that the Künneth formula doesn't hold. A cup product is dened and its main properties are proved.Öğe Common fixed point results on complex valued Gb-metric spaces(Chiang Mai University, 2018) Ege O.; Karaca I.In this study, we introduce some notions such as coincidence point, compatible and occasionally weakly compatible maps in complex valued Gb-metric spaces. Then using these notions we prove some new common fixed point theorems in complex valued Gb-metric spaces. © 2018 by the Mathematical Association of Thailand. All rights reserved.Öğe Digital Borsuk-Ulam theorem(Iranian Mathematical Society, 2017) Burak G.; Karaca I.The aim of this paper is to compute a simplicial cohomology group of some specific digital images. Then we define ring and algebra structures of a digital cohomology with the cup product. Finally, we prove a special case of the Borsuk-Ulam theorem for digital images. © 2017 Iranian Mathematical Society.Öğe The Digital Smash Product(American Mathematical Society, 2020) Cinar I.; Ege O.; Karaca I.In this paper, we construct the smash product from the digital viewpoint and prove some its properties such as associativity, distributivity, and commutativity. Moreover, we present the digital suspension and the digital cone for an arbitrary digital image and give some examples of these new concepts © 2020. American Institute of Mathematical SciencesÖğe The effect of BIS usage on anaesthetic agent consumption, haemodynamics and recovery time in supratentorial mass surgery [Supratentoryal kitlelerde cerrahi si{dotless}rasi{dotless}nda BIS kullani{dotless}mi{dotless}ni{dotless}n anestetik ajan tüketimi, hemodinami ve derlenme süresine etkileri](Turkish Anaesthesiology and Intensive Care Society, 2014) Karaca I.; Akçil F.E.; Dilmen Ö.K.; Köksal G.M.; Tunali Y.Objective: In this study, we aimed to compare Bispectral Index (BIS) monitoring with the conventional anaesthesia approach based on haemodynamic changes in terms of anaesthetic agent consumption,haemodynamic recordings, recovery time and cost. Methods: This study was performed in 82 patients, aged 20 to 60 years, who were operated for supratentorial mass and were graded ASA I or II. Cases were randomly divided into two equal groups. In the standard control group haemodynamic parameters were used to determine depth of anaesthesia and in the BIS group, BIS monitoring was applied. In the BIS group the BIS values were kept between 40 and 60; in the control group haemodynamic changes within the range of +/-20% of initial values were controlled using appropriate anaesthetic practice. Haemodynamic parameters, awakening conditions and drug usage were recorded. Results: The difference between the two groups in terms of timing of eye opening and initial spontaneous breath was not statistically significant. The 'Aldrete' score at the 20th postoperative minute for the BIS group was significantly higher than the score calculated for the control group (p<0.05). Rocuronium consumption (mg kg-1 hr-1) was significantly lower in the BIS group than the control group (p<0.05). Although a statistically significant difference (p<0.05) was found between the two groups in terms of initial heart rate and SpO2 values, there was no clinically significant difference in other haemodynamic parameters. Conclusion: Although using BIS monitoring to evaluate depth of anaesthesia does not bring much benefit versus the use of haemodynamic parameters, it may be beneficial for selected surgeries such as awake craniotomy, for patients with a history of awareness and in haemodynamically unstable patients. © 2014 by Turkish Anaesthesiology and Intensive Care Society.Öğe Effect of Pupil Size on Fixed-Luminance Flicker Full-Field Electroretinogram Magnitude(Dove Medical Press Ltd, 2022) Mobasserian A.; Zaidi M.; Halim S.; Hwang J.J.; Regenold J.; Akhavanrezayat A.; Karaca I.Purpose: Diopsys® NOVA fixed-luminance flicker full-field electroretinogram (ffERG) device is a potential adjunct to conventional flicker ffERG testing for assessing cone cell function. Magnitude of measured electrical response is known to vary with pupil size in conventional ffERG testing. The index study characterizes the relationship between magnitude of measured electrical activity and pupil size, both pupil diameter and pupil area, for this device. Methods: Seventeen patients (34 eyes) with no known ocular diseases were enrolled in the study. Electrophysiologic function of cone cells was evaluated using fixed-luminance flicker ffERG before and after dilation. Linear regression models, with inter-eye correlations controlled as fixed-effects, were used to characterize the effect of pupil dilation on the magnitude of the measured responses. Results: Mean age of study patients was 33.5 (standard deviation 7.4 years), and 35.3% of the subjects were female. Mean value of electrical response magnitude was 10.07±2.79µV before dilation and 15.30±4.08µV after dilation. The correlations of ERG magnitude with pupil diameter and with pupil area were not significant for either dilated or undilated eyes considered separately but were highly significant (p<0.001) for dilated and undilated eyes considered in aggregate. ERG magnitude tended to increase by 1.08 µV for every 1 mm increase in pupillary diameter. Conclusion: An increase in pupil size, both pupil diameter and pupil area, is significantly associated with an increase in flicker ffERG magnitude recorded by the Diopsys device, suggesting that pupil size should be measured and considered when making clinical judgments based on the flicker ffERGs recorded by the device, and that pupil size-specific reference ranges could improve the clinical utility of the device. © 2022 Mobasserian et al.Öğe Evaluation of Ocular Surface and Meibomian Glands Alterations with Meibography in Patients with Inactive Behçet’s Uveitis(Taylor and Francis Ltd, 2019) Karaca I.; Palamar M.; Guven Yilmaz S.; Ates H.Purpose: To evaluate the ocular surface and meibography of patients with inactive Behçet’s uveitis. Methods: Twenty-five right eyes of 25 patients with inactive Behçet’s uveitis (Group 1) and 25 right eyes of 25 healthy individuals (Group 2) were enrolled. Detailed eye examination along with Schirmer 1 test, tear film break-up time (t-BUT), ocular surface staining with fluorescein and Oxford scoring, and ocular surface disease index (OSDI) score assessment were performed. Lower and upper eyelid Meibomian glands were examined with infrared filter of slit-lamp biomicroscope (SL-D701 with DC-4 digital camera and BG-5 background illuminator, TOPCON, Tokyo, Japan (from grade 0 (no dropout of Meibomian glands) to grade 3 (gland dropout >2/3 of the total Meibomian glands)). Results: The mean ages were 36.84 ± 7.39 (range, 23–59) and 33.88 ± 8.25 (range, 18–55) in Group 1 and Group 2, respectively (p = 0.547). When compared with Group 2, in Group 1, best-corrected visual acuity (0.28 vs. 0.00 logMAR, p < 0.001), Schirmer 1 test (18.68 vs. 23.69, p = 0.017) and mean tear film break-up time (10.76 vs. 13.36, p = 0.026) were significantly lower; Oxford scale and OSDI scores were higher (p = 0.039 and p < 0.001, respectively). No significant difference in lower, upper and total (upper + lower) meiboscores were detected in between groups (p = 0.062, p = 0.228 and p = 0.152, respectively). Conclusion: Despite the tendency toward dry eye syndrome, Behçet’s uveitis does not seem to be associated with quantitative Meibomian gland changes, which is demonstrated by gland drop-out with meibography. © 2018, © 2018 Taylor & Francis Group, LLC.Öğe Monomial bases in the mod-p steenrod algebra(2005) Karaca I.In this paper we study sets of some special monomials which form bases for the mod-p Steenrod algebra A.Öğe Multimodal imaging characteristics of quiescent type 1 neovascularization in an eye with angioid streaks(Elsevier Inc, 2018) Mentes J.; Karaca I.; Sermet F.Purpose: To present the multimodal imaging characteristics including optical coherence tomography angiography (OCTA) as well as indocyanine green angiography (ICGA) of quiescent type 1 neovascularization (NV) in an asymptomatic eye with angioid streaks (AS). Observations: A 67-year-old male patient was admitted to our clinic for routine eye examination. The presence of a quiescent type 1 NV was detected on both ICGA and OCTA in juxtafoveal localization under the retinal pigment epitheliumin the right eye. At the end of the one year of follow-up, the patient was asymptomatic and the type 1 NV was still quiescent. Conclusions and Importance: In comparison to ICGA, OCTA seems to be an easily repeatable non-invasive imaging tool which enables us early detection and monitoring of type 1 NV lesions even in asymptomatic patients with AS. © 2018 The AuthorsÖğe The nilpotence height of Pts for odd primes(1999) Karaca I.K. G. Monks has recently shown that the element P-has nilpotence height 2[s/t] + 2 in the mod 2 Steenrod algebra. Here the method and result are generalized to show that for an odd prime p the element Pts has nilpotence height p[s/t] + p in the mod p Steenrod algebra. ©1999 American Mathematical Society.Öğe Nilpotency of atomic steenrod squares(Sciendo, 2017) Ege Ö.; Karaca I.In this paper, we deal with nilpotency of atomic Steenrod squares. We prove that the nilpotence height of atomic square Sq2(2b-1) for all integers b ? 2 is b+2. Finally, we give a nilpotency table, a remark and an important conjecture related to the nilpotence height of atomic squares. © 2018, Universitatii Al.I.Cuza din Iasi. All rights reserved.Öğe Ocular surface assessment and morphological alterations in meibomian glands with meibography in obstructive sleep apnea Syndrome(Elsevier Inc., 2019) Karaca I.; Yagci A.; Palamar M.; Tasbakan M.S.; Basoglu O.K.Purpose: To evaluate ocular surface and Meibomian glands morphology of patients with obstructive sleep apnea syndrome (OSAS). Materials and methods: Based on polysomnography, 36 eyes of 36 patients with severe OSAS (Group 1, apnea-hypopnea index (AHI) ?30/h) and 24 eyes of 24 patients with primary snoring or mild OSAS (Group 2, AHI<15/h) were enrolled. Detailed eye examination along with ocular surface staining (fluorescein, 2%) according to Oxford scale, tear film break-up time (t-BUT), Schirmer 1 test, ocular surface disease index (OSDI) scoring, and evaluation of upper and lower eyelid Meibomian glands using infrared filter of slit-lamp biomicroscope were performed. In addition to grading Meibomian gland drop-out, the presence morphologic alterations such as Meibomian gland duct distortion, thinning and dilatation were also assessed. Results: The mean ages were 50.8 ± 8.3 (range, 35–68) and 47.9 ± 10.5 (range, 27–69) in Group 1 and Group 2, respectively (p = 0.616). Best-corrected visual acuity, Schirmer 1 test, Oxford scale and OSDI scores, and lower meiboscores did not differ significantly between groups. In Group 1, average t-BUT was lower (p = 0.003), upper and total (upper + lower) meiboscores were higher as compared to Group 2 (p < 0.05). The frequency of Meibomian gland duct distortion, thinning and dilatation were also significantly greater in Group 1 (p < 0.05). Conclusion: Morphological changes, in addition to Meibomian glands dropout were significant in severe OSAS patients as demonstrated objectively with meibography. Schirmer 1 and t-BUT tests were in favor of evaporative type dry eye syndrome, which also support Meibomian gland alterations in severe OSAS patients. © 2019 Elsevier Inc.
