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Search Results: 1 - 10 of 401419 matches for " Elif M. Sikoglu "
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Functional Neuroanatomy of Time-To-Passage Perception  [PDF]
Yansong Geng, Elif M. Sikoglu, Heiko Hecht, Lucia M. Vaina
Journal of Behavioral and Brain Science (JBBS) , 2018, DOI: 10.4236/jbbs.2018.811039
Abstract: The time until an approaching object passes the observer is referred to as time-to-passage (TTP). Accurate judgment of TTP is critical for visually guided navigation, such as when walking, riding a bicycle, or driving a car. Previous research has shown that observers are able to make TTP judgments in the absence of information about local retinal object expansion. In this paper we combine psychophysics and functional MRI (fMRI) to investigate the neural substrate of TTP processing. In a previous psychophysical study, we demonstrated that when local retinal expansion cues are not available, observers take advantage of multiple sources of information to judge TTP, such as optic flow and object retinal velocities, and integrate these cues through a flexible and economic strategy. To induce strategy changes, we introduced trials with motion but without coherent optic flow (0% coherence of the background), and trials with coherent, but noisy, optic flow (75% coherence of the background). In a functional magnetic resonance imaging (fMRI) study we found that coherent optic flow cues resulted in better behavioral performance as well as higher and broader cortical activations across the visual motion processing pathway. Blood oxygen-level-dependent (BOLD) signal changes showed significant involvement of optic flow processing in the precentral sulcus (PreCS), postcentral sulcus (PostCS) and middle temporal gyrus (MTG) across all conditions. Not only highly activated during motion processing, bilateral hMT areas also showed a complex pattern in TTP judgment processing, which reflected a flexible TTP response strategy.
Bioenergetic Measurements in Children with Bipolar Disorder: A Pilot 31P Magnetic Resonance Spectroscopy Study
Elif M. Sikoglu, J. Eric Jensen, Gordana Vitaliano, Ana A. Liso Navarro, Perry F. Renshaw, Jean A. Frazier, Constance M. Moore
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0054536
Abstract: Background Research exploring Bipolar Disorder (BD) phenotypes and mitochondrial dysfunction, particularly in younger subjects, has been insufficient to date. Previous studies have found abnormal cerebral pH levels in adults with BD, which may be directly linked to abnormal mitochondrial activity. To date no such studies have been reported in children with BD. Methods Phosphorus Magnetic Resonance Spectroscopy (31P MRS) was used to determine pH, phopshocreatine (PCr) and inorganic phosphate (Pi) levels in 8 subjects with BD and 8 healthy comparison subjects (HCS) ages 11 to 20 years old. Results There was no significant difference in pH between the patients and HCS. However, frontal pH values for patients with BD increased with age, contrary to studies of HCS and the pH values in the frontal lobe correlated negatively with the YMRS values. Global Pi was significantly lower in subjects with BD compared with HCS. There were no significant differences in PCr between the groups. Global PCr-to-Pi ratio (PCr/Pi) was significantly higher in subjects with BD compared with HCS. Conclusions The change in Pi levels for the patients with BD coupled with the no difference in PCr levels, suggest an altered mitochondrial phosphorylation. However, our findings require further investigation of the underlying mechanisms with the notion that a mitochondrial dysfunction may manifest itself differently in children than that in adults. Limitations Further investigations with larger patient populations are necessary to draw further conclusions.
Management of Obstetric Emergencies
Kaz?m Gezgin?,Elif Utku Dalk?l??
Journal of Academic Emergency Medicine , 2011,
Abstract: Pregnancy is a physiological process, but the mother and fetus may encounter complications that require aggressive emergency treatment at any time. Timing of critical events and understanding of the pathophysiology of treatment provide a rapid result. Most obstetric complications cannot be predicted, and pregnancies may be complicated by trying to determine in advance the necessary measures which should be taken and the mother and fetus are evaluated together to minimize maternal and fetal morbidity and mortality. Here, obstetric emergencies and general appraoches will be reviewed.
Management of Gynecologic Emergencies
Kaz?m Gezgin?,Elif Utku Dalk?l??
Journal of Academic Emergency Medicine , 2011,
Abstract: Today, increasing knowledge and experience, together with developing imaging methods and laboratory techniques to evaluate patients with gynecological emergency has facilitated taking necessary general measures to minimize morbidity and mortality. Because this chain of events often develops suddenly, these measures should be taken in advance; applications must be ordered and unhurried. Here, approaches to gynecological emergencies in clinical practice will be reviewed.
Experimental and Theoretical Studies on the Functionalization Reactions of 4-Benzoyl-1,5-Diphenyl-1H-Pyrazole-3-Carboxylic Acid and Acid Chloride with 2,3-Diaminopyridine
Ismail Y?ld?r?m,Fatma Kandemirli,Elif Demir
Molecules , 2005, DOI: 10.3390/10030559
Abstract: The 1H-pyrazole-3-carboxylic acid 2 was converted in good yield (69%) into the corresponding 1H-pyrazole-3-carboxamide 5 via reaction of the acid chloride 3 with 2,3- diaminopyridine (4). A different product, the 3H-imidazo[4,5-b] pyridine derivative 6, was formed from the reaction of 3 with 4 and base in benzene for 5 hours. The structures of the synthesized compounds were determined spectroscopically. The mechanism of the reaction between 3 and 4 was examined theoretically.
Women in Science, Engineering and Technology: Changing Roles and Perception within the Technical Services Industries
Elif Kongar,Paul Kontogiorgis,Nancy L. Russo,Tarek M. Sobh
Journal of Engineering and Applied Sciences , 2012,
Abstract: Services have surpassed agriculture and manufacturing as the leading contributor to gross domestic product in the world today. As the global economy has become more integrated and the demand for a workforce required to run service-focused organizations in an efficient manner grows, the level and variety of skills needed in this new service economy have also changed and grown. In particular, the growth rate of technology-driven service industries is significantly outpacing the growth in other service-oriented sectors. It has been argued that women in general possess many characteristics that make them optimal candidates to fulfill this workforce gap. However, the percentage of women enrolled in engineering, technology and related programs have been dropping. This study attempts to create an awareness of the skills and job roles required for future labor workforce demands in the engineering and technology services industry and argues that these current and future roles makes them more appealing to women.
Incidence of Actinomycosis in Tonsillectomized Patients: Histopathologic Data for 115 Cases and a Rare Localization of Actinomycosis in Tongue Base
Emine Elif Altunta?,Aynur Engin,Hatice ?zer,Suphi Müderris
Klimik Journal , 2010,
Abstract: Objective: In this study, we aimed to investigate the detection rate of histopathologically confirmed actinomycosis in tonsillectomized cases, during a 19-year period. A case with actinomycosis in a rare localization such as the tongue root is also reported and, in this case, our diagnosis and treatment approach is overviewed with the literature.Methods: 1047 patients who underwent tonsillectomy for various reasons between January 1990 and December 2009 in the Department of Otorhinolaryngology, Faculty of Medicine, Cumhuriyet University were investigated retrospectively. The surgical materials of 115 (11%) cases with suspicious macroscopic appearance of tonsillar tissue, unilateral tonsillar hypertrophy and suspected malignancy on clinical examination were evaluated histopathologically.Results: In this study, 66 (57.4%) cases were male and 49 (42.6%) female. A chronic granulomatous process and colonies of actinomycetes were reported pathologically in 32 (27.8%) cases and a chronic inflammatory process in 83 (72.2%) cases.Conclusions: Despite the medical and economic burden, all surgical specimens obtained from cases who underwent tonsillectomy and adenoidectomy should be examined histopathologically as well as specimens from patients with suspected malignancy. We think that this clinical approach will contribute not only to make an early diagnosis and to determine the frequency of tonsillar cancers that are rarely seen in childhood, but also to determine the role of actinomycosis in the etiology of chronic tonsillitis and adenoid vegetation.
Motivations Determining Participation in Rural Recreations: Example of University Students
Haldun Müderriso lu,Zeki Demir,Elif Lütfiye Kutay
Journal of Applied Sciences , 2005,
Abstract: In this study, the aim was to find out the activity preferences of the visitors of rural recreation areas, to determine the motivations of these visitors and finally to determine the areas and activities they preferred with the motivations. For this purpose, 250 students of Abant Izzet Baysal University were questioned. From the data obtained, factor analysis with varimax rotation method was used in order to explain participations in rural recreation and motivations. Correlation analysis was used in order to explain the relationships of the determined factors with each other and user characteristics. According to the results obtained, characteristics of recreational area, the type of recreational activity and characteristics of social structure are effective in forming the motivations.
Improved selectivity from a wavelength addressable device for wireless stimulation of neural tissue
Elif ?. Seymour,David S. Freedman,Mesut Sahin,M. Selim ünlü
Frontiers in Neuroengineering , 2014, DOI: 10.3389/fneng.2014.00005
Abstract: Electrical neural stimulation with micro electrodes is a promising technique for restoring lost functions in the central nervous system as a result of injury or disease. One of the problems related to current neural stimulators is the tissue response due to the connecting wires and the presence of a rigid electrode inside soft neural tissue. We have developed a novel, optically activated, microscale photovoltaic neurostimulator based on a custom layered compound semiconductor heterostructure that is both wireless and has a comparatively small volume (<0.01 mm3). Optical activation provides a wireless means of energy transfer to the neurostimulator, eliminating wires and the associated complications. This neurostimulator was shown to evoke action potentials and a functional motor response in the rat spinal cord. In this work, we extend our design to include wavelength selectivity and thus allowing independent activation of devices. As a proof of concept, we fabricated two different microscale devices with different spectral responsivities in the near-infrared region. We assessed the improved addressability of individual devices via wavelength selectivity as compared to spatial selectivity alone through on-bench optical measurements of the devices in combination with an in vivo light intensity profile in the rat cortex obtained in a previous study. We show that wavelength selectivity improves the individual addressability of the floating stimulators, thus increasing the number of devices that can be implanted in close proximity to each other.
An Intersting Case: A Long Pin in the Nose  [PDF]
Ilhan Unlu, Elif Nisa Unlu
International Journal of Clinical Medicine (IJCM) , 2014, DOI: 10.4236/ijcm.2014.517137
Abstract: Intranasal foreign bodies are very common problems for ENT practitioners. However, very few case reports of a long pin in the nose are described in the literature. Our case had a pin measured as 33.9 millimeters in the right nasal vestibule, but the patient was not aware of it when she came to us. Actually she was suffering from a headache and nasal obstruction. After removal of the foreign body, the patient’s complaints were resolved.
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