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Exploring the Role of Search Experience and Self-Efficacy in Cognitive Self-Esteem: a Latent Growth Modelling Approach
No full textIn this study, we seek to contribute to a broader understanding of the processes and contexts that lead to inflated judgments of cognitive ability in human-computer partnerships. We conducted a within-subject experiment design study with 164 college students in order to explore the impact of the search experience on cognitive self-esteem (CSE). Our preliminary findings revealed that search experience is an important factor that influences individuals' perception of their abilities to answer questions. This influence was observed regardless of whether they have access to search tools or not. However, search experience does not explain the significant change in CSE that we found between "access" and "no access" (to search tools) conditions
Protective Effects of Metformin in Non-Diabetic Rats With Experimentally Induced Lower Extremity Ischemia-Reperfusion Injury
No full textAim: Lower extremity ischemia-reperfusion (IR) injury can lead to substantial skeletal muscle damage and systemic complications, primarily driven by oxidative stress and inflammation. In addition to its well-known glucose-lowering effects, metformin possesses antioxidant and anti-inflammatory properties that may confer protection against tissue damage caused by IR. This study aims to evaluate the potential protective effects of metformin on skeletal muscle injury using a rat model of lower extremity IR.Material and Methods: A total of twenty-four male Wistar albino rats were randomly divided into four experimental groups: Control (C), Ischemia-Reperfusion (IR), IR with metformin at 4 mg/kg (IR+M4), and IR with metformin at 8 mg/kg (IR+M8). Ischemia was induced by clamping the infrarenal aorta for 45 minutes, followed by a reperfusion period of 120 minutes. In the treatment groups, metformin was administered intraperitoneally at the onset of ischemia. Gastrocnemius muscle tissues were harvested for subsequent histopathological and biochemical evaluations, including measurements of Total Antioxidant Status (TAS), Total Oxidant Status (TOS), and Oxidative Stress Index (OSI).Results: Histopathological analysis demonstrated a significant reduction in muscle atrophy, degeneration, leukocyte infiltration, and fiber fragmentation in the IR+M8 group compared to the IR group. Biochemical assessments showed that TAS levels were considerably elevated, whereas TOS and OSI levels were markedly reduced in the metformin-treated groups, with the most prominent effects observed at the higher dosage of 8 mg/kg.Conclusion: The findings indicate that metformin exerts a dose-dependent protective effect against skeletal muscle injury resulting from lower extremity ischemia-reperfusion in rats. These protective properties are likely due to metformin’s antioxidant and anti-inflammatory mechanisms, highlighting its potential therapeutic value in mitigating IR-induced tissue damage
Epistemic Extraction Zones in Migration Studies: Rethinking Over-Research and Research Fatigue Among Syrian Refugees in Turkey
No full textThis paper explores the phenomenon of over-research among Syrian refugees in Turkey, highlighting how sustained and repetitive research attention has created research saturation zones that shape both refugee experiences and knowledge production. Drawing on unstructured conversations with six Syrian refugees in Ankara, the study examines how research fatigue manifests not only as reluctance to participate but also as strategic responses through which refugees navigate frequent encounters with researchers. While existing literature has addressed research fatigue and ethics in refugee studies, less attention has been given to how academic incentives, humanitarian logics, and policy imperatives intersect to produce systematic inequalities in knowledge production. To address this gap, the paper advances the concept of epistemic extraction zones, referring to contexts where knowledge is persistently mined from marginalized communities to satisfy institutional demands with limited reciprocity or epistemic agency. This conceptual lens shifts the debate from individual withdrawal to the structural political economy of knowledge production. The analysis identifies three key dynamics. First, the emergence of research saturation zones in contexts of protracted displacement, where the same communities are repeatedly targeted for study; second, refugees' strategic yet ambivalent engagement with research, combining pragmatic hope with critical awareness of its limited effects; and third, the paradoxical consequences of over-research, where intensified attention produces epistemic extraction that narrows the circulation of knowledge and reinforces hierarchies. The article also reflects critically on the researcher's own position within these dynamics. By theorizing epistemic extraction zones, the paper contributes not only to refugee studies but also to broader sociological debates on power, inequality, and the ethics of knowledge production, highlighting the need for more reflexive and politically accountable research practices.Middle East Technical University Northern Cyprus Campus Scientific Research and Publication Ethics BoardI would like to express my gratitude to Dr. Huriye Gokten Dogangun for her collaborative support during the fieldwork that made this research possible. I am deeply grateful to the Syrian refugee participants who generously shared their perspectives and experiences despite research fatigue. I also wish to thank [include any colleagues who provided feedback on drafts, helped with translation if applicable, or offered intellectual guidance]. Additionally, I acknowledge the Middle East Technical University Northern Cyprus Campus Scientific Research and Publication Ethics Board for their ethical oversight of the original research from which this study emerged
Modeling Low Radar Cross Section UAV at Simulation And Real Environment In X-Band
Get PDFBu tezde, düşük RKA değerli bir İHA hem simülasyon hem de gerçek ortamda modellenmiş ve ölçülmüş, ayrıca sonuçlar incelenerek model en düşük RKA değerlerine sahip olacak şekilde iyileştirilmiştir. Hesaplamalı yöntemler arasında en yaygın kullanılan RKA tahmin programlarından biri olan CST, düşük RKA değerli İHA'yı modellemek ve simülasyon ortamında ölçmek için kullanılmıştır. Önerilen RKA Azaltma tekniği, modelleme aşamaları ve düşük RKA değerli İHA'nın parçalarında dikkat edilmesi gereken hususlar tanımlanmış ve simülasyon ortamında belirtilmiştir. Tüm ölçümler 360 derecelik görünüş açısında (1 derece hassasiyette) ve X-Band'da hem dikey hem de yatay polarizasyonda alınmıştır. Düşük RKA değerli İHA simülasyon ortamında modellendikten ve düşük RKA değerleri kanıtlandıktan sonra, profesyonel bir 3 boyutlu yazıcı yardımıyla gerçek ortamda modellenmiştir. Gerçek ortamda, düşük RKA değerli İHA'nın saçılma alanı parametreleri Vektör Ağ Analizörü (VNA) ile ölçülmüş ve saçılma alanına dayalı bir formül kullanılarak RKA parametreleri hesaplanmıştır. Gerçek ortam testleri için, tüm ölçümler 360 derecelik görünüş açısında (10 derece hassasiyette) ve X-Band'da hem dikey hem de yatay polarizasyonda alınmıştır. Ölçülen ve hesaplanan gerçek ve simüle edilmiş ortam sonuçları karşılaştırılarak sonuçların birbirine benzer olduğu kanıtlanmıştır. Hem simülasyon hem de gerçek ortamdaki sonuçlar, önerilen RKA azaltma tekniğinin yardımıyla, İHA'daki RKA değerlerinin önemli ölçüde azaldığını göstermektedir. Son olarak, en düşük RKA değerleri, Düşük-RKA İHA incelenip yeniden geliştirilerek Geliştirilmiş İHA ile elde edilmiştir.In this thesis, a low RCS UAV was modeled and measured in both simulation and real environments, and the results were examined to improve the model to have the lowest RCS values. CST was used to model the low RCS UAV and measure it in the simulation environment which is one of the most widely used RCS estimation programs among computational methods. The proposed RCS Reduction technique, modeling stages and the points to be considered in the parts of the low RCS UAV were defined and specified in the simulation environment. All measurements were taken at 360-degree aspect angle (1-degree precision) and in both vertical and horizontal polarization in X-Band. After the Low-RCS UAV was modeled in the simulation environment and the low RCS values were proven, it was modeled in the real environment with the help of a professional 3D printer. In real environment, the scattering field parameters of Low-RCS UAV were measured with the Vector Network Analyzer (VNA) and the RCS parameters were calculated using a formula based on the scattering field. For real environment tests, all measurements were taken at 360-degree aspect angle (10-degree precision) and both vertical and horizontal polarization in X-Band. The measured and calculated real and simulated environment results were compared to prove that the results were similar to each other. Both simulated and real environment results show that with the help of the proposed RCS Reduction technique, the RCS values in the UAV were significantly reduced. Finally, the lowest RCS values were obtained with the Improved RCS UAV by examining and redeveloping the Low-RCS UAV
Toxoplasma gondii Coinfection in HIV-Positive Patients at a Tertiary Care Hospital
No full textKurkcu, Muhammed Furkan/0000-0002-7750-5002Introduction: Toxoplasma gondii (T. gondii) can cause serious complications in both immunocompetent and immunosuppressed individuals. This study aims to assess the seroprevalence of T. gondii among HIV-positive individuals and to investigate its association with age, sex, CD4+ T cell count, HIV RNA levels, and hematological parameters. Methods: This study included 247 HIV-positive individuals followed up at a tertiary care hospital between November 1, 2022, and November 30, 2024. We analyzed serum samples for T. gondii IgG antibodies using electrochemiluminescent microparticle immunoassay. Results: The prevalence of T. gondii IgG seropositivity was found to be 32.8% (n=81; 95% CI: 26.9-39). The median age of seropositive individuals was 52 years (IQR: 42-61), which was significantly higher compared to seronegative individuals (p<0.001). The highest IgG seropositivity rate (66.7%) was observed in the 61-80 age group. Hemoglobin levels were significantly lower in IgG seropositive individuals (p=0.040). Logistic regression analysis indicated an increased risk of T. gondii infection with advancing age. The odds ratio for the 41-60 age group was 13.3 (95% CI: 1.6-106, p=0.02), while for the 61-80 age group, it was 28 (95% CI: 3.3-240, p=0.002). Discussion: The seroprevalence of T. gondii in HIV-positive individuals was lower than both global and regional averages. Age was identified as an independent risk factor for T. gondii seropositivity. Additionally, hematological alterations associated with anemia were observed in seropositive individuals. Further large-scale, multi-center, and regionally representative studies are required to optimize T. gondii infection management and screening strategies in people living with HIV. Conclusion: These findings suggest that T. gondii infection in HIV-positive individuals increases with age and may be associated with anemia, highlighting the need for age-focused screening and management strategies
Investigation of Tetanus Seropositivity Levels in Adult Patients with Rabies Risk Exposure Admitted to a Hospital in Ankara
No full textGürkaynak, Pınar/0000-0001-8863-8268; Tuncer Ertem, Gunay/0000-0001-8760-0030Introduction: This study aimed to assess tetanus seropositivity levels among adult patients admitted to a tertiary care hospital following rabies risk exposure, and to explore potential factors influencing their immunological status. Methodology: This cross-sectional descriptive epidemiological study included 182 adult individuals (68 females and 114 males) who presented to the hospital following rabies risk exposure. The demographic data was collected during a face-to-face interview, and the tetanus antibody concentrations were assessed using a micro-enzyme-linked immunosorbent assay (ELISA) kit. Serum antibody levels of >= 0.1 IU/mL were defined as "seropositive", while values below this threshold were considered "seronegative". Results: Seropositivity was identified in 81.9% of the patients. There was a significant decline in antibody levels with age (p < 0.001). The Spearman correlation analysis showed a moderately significant negative correlation between age and antibody titers (r = - 0.404, p < 0.001). In addition, there were significantly higher tetanus antibody levels in patients from urban areas, those vaccinated during pregnancy, and those vaccinated within the past 10 years (p = 0.025, 0.036, and 0.013, respectively). Conclusions: Overall, the results highlight a reduction in tetanus antibody levels with age, emphasizing the importance of receiving a booster dose every 10 years. In addition, rabies risk exposure, particularly in older adults, presents a valuable opportunity to administer tetanus vaccination.Health Sciences University Ankara Training and Research Hospital Education Planning Board [48865165-302.14.01]Funding This study was funded by a grant from the Health Sciences University Ankara Training and Research Hospital Education Planning Board (Project Number: 48865165-302.14.01)
Hegemonık Erkekliğin İnşası: Fitness ve Oyunların Kesişimi
No full textBu araştırma, hegemonik erkekliğin inşası çerçevesinde fitness ve oyun alanlarına ilişkin tüketim pratiklerinin kesişimine odaklanmaktadır. Nitel araştırma paradigması içerisinde, her iki alanda da aktif olarak yer alan yedi erkek katılımcı ile yarı yapılandırılmış görüşmeler gerçekleştirilmiştir. Altı aşamalı tematik analizin sonuçları altı farklı tema ortaya koymuştur: üstünlük ve rekabetçilik, güç ve performans, başarılar ve kazançlar. Bu alanlardaki tüketim, normatif ve yüceltilmiş eril değerleri güçlendirmektedir. Katılımcılar, Baudrillard'ın eril tüketim modeline uygun olarak nesnel ve rasyonelleştirilmiş tüketim pratiklerini vurgulamışlardır. Bulgular, fitness ve oyunların hegemonik erkekliğin tüketim kalıpları aracılığıyla sürdürüldüğü platformlar olarak algılandığını göstermektedir. Çalışma, tüketimin cinsiyete dayalı boyutlarını vurgulayarak rasyonel tüketici davranışı varsayımlarına meydan okumaktadır. Ayrıca alternatif, kapsayıcı erkeklik anlayışlarını teşvik etmek için geleneksel toplumsal cinsiyet normlarının yapısöküme uğratılmasının öneminin altını çizmektedir. İleride yapılacak araştırmalar, kadın katılımcılar kapsayacak farklı perspektifleri içermelidir
Spline Based Sparseness and Smoothness for Partially Nonlinear Model Via C-Fused Lasso
No full textOne of the most beneficial and widely used models for data analysis are partially nonlinear models (PNLRM), which consists of parametric and nonparametric components. Since the model includes the coefficients of both the parametric and nonparametric parts, the complexity of the model will be high and its interpretation will be very difficult. In this study, we propose a procedure that not only achieves sparseness, but also smoothness for PNLRM to obtain a simpler model that better explains the relationship between the response and covariates. Thus, the fused Lasso problem is taken into account where nonparametric components are expressed as a spline basis function, and then the Fused Lasso estimation problem is built and expressed in terms of conic quadratic programming. Applications are conducted to evaluate the performance of the proposed method by considering commonly utilized measures. Promising results are obtained, especially in the data with nonlinearly correlated variables. © (2025), (American Institute of Mathematical Sciences). All rights reserved.Science Citation Index Expande
A New Conservative Numerical Method for Strongly Coupled Nonlinear Schrödinger Equations
No full textIn this paper, a numerical method based on the conservative finite difference scheme is constructed to numerically solve the strongly coupled nonlinear Schr & ouml;dinger (SCNLS) equation. Conservative properties such as energy and mass of the SCNLS equation have been proven. In particular a fourth-order central difference scheme is used to discretize the the spatial derivative and a second-order Crank-Nicolson type discretization is used to discretize the temporal derivative. It has been shown that the proposed scheme preserves the discrete mass and energy. The existence of discrete solution is also investigated. Several numerical results are given to demonstrate the preservation properties of the new method. Also, the effect of the linear coupling parameters on the evolution of solitary waves is investigated
Differences of Microbial Growth and Biofilm Formation Among Periprosthetic Joint Infection-Causing Species: an Animal Study
No full textPurpose: The most frequently used surgical procedures for periprosthetic joint infections (PJIs) are debridement, antibiotics, and implant retention (DAIR), as well as single- or two-stage revision arthroplasty. The choice of surgery is made depending on the full maturation of the biofilm layer. The purpose of this study was to evaluate the biofilm formation and microbial growth using common PJI-causing agents and compare its development on the implant surface. Methods: The in vivo study was performed using 40 Sprague–Dawley rats divided into five groups (n = 8/group): Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Candida albicans, and control. Six standard titanium alloy discs were placed into the subcutaneous air pouches of the interscapular areas of the rats. After the inoculation of microorganisms, disc and soft tissue cultures were collected at 2-week intervals for 6 weeks, and the microbial load and the microscopic appearance of the biofilm were compared. Results: The disc samples from the S. aureus group had the highest infection load at all time points; however, in soft tissue samples, this was only observed at week 4 and 6. Electron microscopic images showed no distinctive differences in the biofilm structures between the groups. Conclusion: S. aureus microbial burden was significantly higher in implant cultures at week 2 compared to other PJI-causing agents examined. These results may explain the higher failure rate seen if the DAIR procedure was performed at < 3–4 weeks after the PJI symptom onset and support the observation that DAIR may not be effective against PJIs caused by S. aureus. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.University Scientific Research Projects Fund, (19L0230016