Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dokuz, Abdurrahman(6)
- Maden, Nafiz(5)
- Arslan, Mehmet(4)
- Kandemir, Raif(4)
- Karsli, Orhan(4)
- Kaygusuz, Abdullah(4)
- Acet, Tuba(3)
- Akaryali, Enver(3)
- Aydin, Faruk(3)
- Gücer, Mehmet Ali(3)
- Hisarlı, Z. Mümtaz(3)
- Merdan, Mehmet(3)
- Topal, Fevzi(3)
- Yücel, Cem(3)
- Özcan, Kadriye(3)
- Adiguzel, Ahmet(2)
- Adiguzel, Gulsah(2)
- Aktaş, Gülten(2)
- Akyürek, Suat(2)
- Alemdag, Selcuk(2)
- Aslan, Zafer(2)
- Bozkurt, Ferhat(2)
- Coskuncay, Ahmet(2)
- Eyuboglu, Yener(2)
- Faiz, Ozlem(2)
- Genc, Berna(2)
- Genç, Gökhan(2)
- Gökdoĝan, Ahmet(2)
- Günen, Mehmet Akif(2)
- Güzel, Melih(2)
- Kaya, Selim(2)
- Küçük, Mehmet Ali(2)
- Odabaş, Halil İbrahim(2)
- Ozturk, Samet(2)
- Santosh, M.(2)
- Sari, Bilge(2)
- Sari, Mahmut(2)
- Sipahi, Ferkan(2)
- Sisecioglu, Melda(2)
- Temizel, İrfan(2)
Yayınlar
- MakaleAçık Erişim2025Experimental determination of the compression behavior of RTV silicone rubber-based magnetorheological (MR) materials under static loading
Mazlum, Ugur; Celik, Ilhan
In this study, MR elastomer (MRE) materials were produced using seven different types of silicone rubber and five different types of magnetically sensitive ferromagnetic powders. The MRE materials were obtained in three states: pure, isotropic (homogeneous), and anisotropic (aligned). Compression tests were conducted using a uniaxial testing machine, with engineering stress–strain curves, tangent modulus, and MR-strain behavior graphs generated, considering powder ratio, powder type, and hardness values. The goal was to investigate the positive effects of magnetic field influence on these parameters and how the alignment state affected the stress performance of the materials. As a result, the highest stress increase at 10% strain was observed in materials containing 40% powder, with magnetic field comparison showing the most significant results. With the EM powder type at a 30% powder ratio in the isotropic state, a 563% increase in stress was obtained. Among the matrix materials with the same hardness, the most robust material was determined to be the MM240 TV with a Shore hardness of 40. Furthermore, the most significant increase in tangent modulus under the influence of the magnetic field was observed in vertically aligned materials. Compared to the pure material, a 3127% increase was found at 0.57% strain in vertically aligned samples. In materials with Shore hardness of 2, using Basf CN powder at 10–40% powder ratios, the highest relative MR effect was observed at a 20% powder ratio. The stress increase for vertically aligned samples compared to the pure state was 1274.6% at 0.27% strain. When comparing the relative MR effect of materials with Shore hardness between 10 and 59, the largest increase was obtained from the Sorta Clear matrix material.
- MakaleYalnız künye2025One-step kinetic analysis of Listeria innocua growth as a surrogate for Listeria monocytogenes on arugula leaves with background microbiota: model development and validation
Ozturk, Samet
This study investigated the growth kinetics of L. monocytogenes and L. innocua on fresh arugula leaves under abusive conditions, considering the presence of background microbiota (BM) including (APC (Aerobic Plate Count), TPC (Total Psychrotrophic Count), and LAB (Lactic Acid Bacteria)). Additionally, the feasibility of using L. innocua as a surrogate for L. monocytogenes was evaluated for industrial practices. Predictive models were developed to assess the effect of temperature and time on the growth kinetics of both microorganisms. Experiments were conducted in triplicate to observe growth kinetics at temperatures from 5 to 35°C. The growth curves were analyzed using one-step analysis with the USDA IPMP-Global Fit software, employing the Huang full/no-lag phase growth as the primary models and the Huang sub-optimal (HSRM) and Ratkowsky sub-optimal square-root as the secondary models. An additional set of isothermal data, collected at 15°C and 20°C, was used to validate the models. Results showed that the minimum growth temperatures were 2.91±0.50°C for L. monocytogenes and 2.88±0.50°C for L. innocua, while 2.05±0.89, 1.93±0.98 and 3.55±1.97°C for APC, TPC and LAB, respectively. The specific growth rates of L. monocytogenes and L. innocua ranged from 0.01 to 0.93 h⁻¹. The root mean square error (RMSE) of model validation and development was less than 0.3 log CFU/g, indicating that the combination of the Huang growth model with HSRM could accurately predict the growth of L. monocytogenes under abusive conditions. Validated models can provide useful input to quantitative risk assessment tools to predict the growth of L. monocytogenes on arugula leaves in the presence of BM during distribution or storage. The findings of this study support the use of L. innocua with R2=0.961 as a suitable surrogate in industrial practices for fresh produce.
- MakaleYalnız künye2025Mantle genesis and crustal contamination in Carboniferous granitoids using U-Th-K concentrations at the Akşar Pluton in the Eastern Pontides, NE Türkiye
Maden, Nafız; Gücer, Mehmet Ali; Akaryalı, Enver
New radiogenic heat production (RHP) data are presented for Carboniferous granites outcropping in the Akşar region (Bayburt, NE Turkey) to contribute to ongoing debates on the genetic and lithologic relationship between the Akşar and Gümüşhane plutons, which is the most widely distributed granitic rocks in the region. The scope of this study consists of rocks composed of enriched mantle material metasomatized by fluids from the previously subducted plate. We observed average K value for the Akşar Pluton was found to be 3.09 ± 1.58 %. Additionally, average Th/U and U/Th values of 3.95 ± 1.37 and 0.29 ± 0.10, respectively. The calculated RHP value for the Akşar Pluton was 2.20 ± 0.56 μWm−3. Numerical results suggest that the Carboniferous Akşar pluton's primary magma was the product of mixing lithospheric mantle and mid-to-lower crustal melts because of partial melting, differentiation, and emplacement in the shallow continental magma chamber. The geochemical and petrogenetic characteristics of the Akşar region magmas suggest that crustal contamination occurred at multiple levels, particularly within the lower to middle crust of the plutonic core complex. This complex likely retains geochemical signatures indicative of subducted Paleotethys oceanic lithosphere. These findings provide critical insights into the magmatic evolution of the Eastern Pontides, contributing to a more comprehensive understanding of crust–mantle interactions and the broader geodynamic framework of northeastern Türkiye.
- MakaleAçık Erişim2025Combined innovative trend analysis methods for seasonal trend testing
Şan, Murat
While holistic trend identification is essential, it does not consider the periodic, e.g., monthly, trend characteristics needed to identify seasonal trend behavior. Furthermore, identifying seasonal trends can help manage or regulate water resources systems and irrigation and agricultural operations. In this study, the innovative trend significance test (ITST), the revised ITST, and the Wilcoxon signed-rank test, which are non-parametric methods, are proposed as alternative seasonal trend tests by combining them with the innovative polygon trend analysis (IPTA), which provides visual and linguistic examinations of seasonal behaviors. Groundwater level data from the Chilgrove House (United Kingdom), flow data from the Danube River Basin (Romania), precipitation and temperature data from Türkiye were used to compare the proposed methods with the seasonal Mann-Kendall (SMK) method. For temperature and groundwater level data, all methods showed an increasing trend at different confidence intervals, but for other data, trends emerged according to the characteristics of the methods. So, some of the proposed methods are more rigid than the SMK in trend detection, while others are more sensitive. In addition to the advantage of its applications to seasonal trend behaviors, the proposed significance tests are combined with the IPTA method and comparable alternative methods to the SMK. So, seasons with a clear increase or decrease can be seen visually in the proposed combined methods contrary to the SMK method. Thus, both seasonal trend behaviors and inter-seasonal transitions can be examined graphically, and seasonal significance testing can be applied. According to the characteristics of these combined methods, they can be used not only for seasonal trend tests, just like the SMK method, but also for regional trend tests using stations data instead of seasons.
- MakaleAçık Erişim2025Volumetric and microstructural changes in the Hippocampus and cingulum in children with west syndrome
PALANCI, Özgür; KAMAŞAK, Tülay; AYDIN KASAP, Zeliha; EYÜBOĞLU, İlker; DİLBER, Beril; CANSU, Ali
Purpose: We aimed to investigate structural changes in the hippocampus using automated segmentation techniques to evaluate the anatomy and function of the hippocampus in patients with West syndrome (WS). Methods: The study included 48 participants (24 with WS and 24 healthy controls) aged 0‐4 years. Automated segmentation methods were used to measure hippocampal volume and evaluate diffusion tensor imaging (DTI) parameters such as fractional anisotropy (FA) and mean diffusivity (MD). Bonferroni correction was applied for multiple comparisons, setting the adjusted significance threshold at p < 0.0033. Results: Children with WS exhibited significantly reduced total hippocampal volume and diminished volumes in the CA2–CA3, CA4-dentate gyrus (CA4-DG), and SR-SL-SM regions compared to healthy controls (padj <0.0033). After correction, no significant differences were found in the CA1 and subiculum regions (padj >0.0033). Although initial comparisons between ongoing WS and seizure-controlled WS suggested increased volumes in several hippocampal regions in the seizure-controlled group, these differences did not remain significant after adjustment and must be interpreted with caution. Notably, patients with seizure-controlled WS displayed larger hippocampal volumes, higher FA, and lower MD values, indicating a possible link between seizure activity and structural alterations. Additionally, DTI analysis of the cingulum revealed lower FA and higher MD values in WS patients, suggesting compromised microstructural integrity. Conclusions: These findings emphasize the potential role of hippocampal alterations in the pathophysiology of WS and suggest that DTI parameters may serve as useful measures for monitoring disease progression and treatment response.
- MakaleAçık Erişim2025Protective effect of tarantula cubensis extract on ischemia-reperfusion injury in rat ovaries: Immunohistochemical, biochemical and histopathological evaluations
Paksoy, Zahid; Ozturk Sarikaya, Sevim Beyza; Yumusak, Nihat
Ischemia-reperfusion (IR) injury is a common pathology affecting the ovary. This study aimed to investigate the effect of Tarantula cubensis extract (TCE) on ovarian IR injury. Forty-two female rats were used and randomly divided into 7 groups: Control, Sham, IR, Ischemia+TCE+Reperfusion, TCE+IR, Ischemia+Ethanol+Reperfusion and Ethanol+IR. The control and sham groups did not receive any treatment. All other groups were subjected to 3 h of ischemia + 3 h of reperfusion. A single dose of TCE (0.2 ml Theranekron) was administered subcutaneously either before or after ischemia in the treatment groups. In the last 2 groups, ethanol was applied before or after ischemia. After reperfusion, blood samples were collected and analyzed for biochemical parameters. Additionally, the ovarian tissue was evaluated histopathologically and immunohistochemically. The IR group exhibited more marked hyperemia, hemorrhage, and necrosis. Both treatment groups showed histopathological improvement. Moreover, the recovery rate was greater in the animals given theranekron before ischemia. IR injury caused oxidative stress in the rats. However, Theranekron did not significantly reduce the MDA levels (p > 0.05). On the other hand, SOD levels were significantly increased in the treatment groups (p < 0.01). Compared to the control and sham groups, the IL-1β, IL-6 and TNF-α levels were very high in the IR group. Conversely, the immunoreactivity of these cytokines was further reduced in the animals given theranekron before ischemia. Our findings suggest that TCE may be beneficial in the treatment of ovarian IR damage, especially when Theranekron is given before ischemia.
- MakaleYayıncıda açık erişim2025GeMID: Generalizable models for IoT device identification
Kostas, Kahraman; Yasa Kostas, Rabia; Just, Mike; Lones, Michael A.
With the proliferation of devices on the Internet of Things (IoT), ensuring their security has become paramount. Device identification (DI), which distinguishes IoT devices based on their traffic patterns, plays a crucial role in both differentiating devices and identifying vulnerable ones, closing a serious security gap. However, existing approaches to DI that build machine learning models often overlook the challenge of model generalizability across diverse network environments. In this study, we propose a novel framework to address this limitation and to evaluate the generalizability of DI models across data sets collected within different network environments. Our approach involves a two-step process: first, we develop a feature and model selection method that is more robust to generalization issues by using a genetic algorithm with external feedback and datasets from distinct environments to refine the selections. Second, the resulting DI models are then tested on further independent datasets to robustly assess their generalizability. We demonstrate the effectiveness of our method by empirically comparing it to alternatives, highlighting how fundamental limitations of commonly employed techniques such as sliding window and flow statistics limit their generalizability. Moreover, we show that statistical methods, widely used in the literature, are unreliable for device identification due to their dependence on network-specific characteristics rather than device-intrinsic properties, challenging the validity of a significant portion of existing research. Our findings advance research in IoT security and device identification, offering insight into improving model effectiveness and mitigating risks in IoT networks.
- MakaleAçık Erişim2025Development of analytical methods and method validation for the qualitative and quantitative determination of Carboxymethyl Cellulose (CMC) in yogurt and ayran
Ergüney, Gülşen; Gündoğdu, Engin; Baltaci, Cemalettin
This study presents the development and validation of analytical methods for the qualitative and quantitative determination of Carboxymethyl Cellulose (CMC) in yogurt and ayran. The methods were evaluated for their detection limit (LOD), quantification limit (LOQ), and method detection limit (MDL) across multiple samples, demonstrating robust sensitivity with MDL and LOD values of 0.03% for both yogurt and ayran. Recovery studies showed high accuracy, with recovery rates between 98% and 100%, and consistent recovery within the acceptable range of 97–103%, reinforcing the methods' reliability. The quantitative analysis exhibited strong repeatability and reproducibility, with low relative standard deviations (RSDr and RSDR), confirming minimal intra-day and inter-day variability. The calibration curves for CMC analysis demonstrated excellent linearity with high coefficients of determination (R2 = 0.9985 for yogurt and 0.9951 for ayran), ensuring accurate quantification over a wide concentration range. Measurement uncertainty analysis further validated the methods' precision and accuracy, showing low relative uncertainties for trueness, repeatability, and reproducibility. Robustness evaluations indicated that the methods maintained consistent recovery rates despite variations in pH, heating time, and sample quantity, highlighting their reliability under different conditions. For qualitative analysis, the visual images method showed exceptional performance with perfect sensitivity and specificity, accurately identifying all positive and negative samples without any false positives or negatives. This high level of accuracy makes the visual images method a valuable tool for ensuring product safety and compliance with quality standards in the dairy industry. Overall, the validated analytical methods for CMC detection in yogurt and ayran demonstrated high precision, accuracy, and reliability, making them essential for quality control and regulatory compliance in dairy production.
- MakaleYalnız künye2025Ecological footprint components and agricultural productivity: Insights from MENA countries
Recepoğlu, Mürşit; Hayaloğlu, Pınar; Cakir, Sümeyra Cay; Artan, Seyfettin; Cakir, Mehmet Ali
The surge in the global population over the past century has highlighted the importance of agricultural production, leading to many studies to boost productivity. Unlike previous studies that primarily explore agricultural productivity growth, this study investigates how the subcomponents of the ecological footprint affect agricultural productivity in MENA countries between 1992 and 2021, identifying which types of environmental pollution have the most significant impact. Driscoll and Kraay (1998) method results show that ecological footprint has a major negative impact on agricultural productivity. Similarly, all ecological footprint components have a negative impact on agricultural productivity. The forest footprint has the highest coefficient magnitude, followed by crop land footprint, carbon footprint, fishing grounds footprint and grazing land footprint. The results have been tested for robustness using the Half-Panel Jackknife test to avoid biased results, and parallel results have been obtained. Finally, the causality between agricultural productivity and explanatory variables has been tested using Dumitrescu and Hurlin (2012) panel causality test. The findings suggest that policymakers may find it more effective to eliminate pollution rather than using additional resources to increase agricultural productivity. This approach allows for the reallocation of resources used in agricultural production to other areas.
- MakaleAçık Erişim2025Utilization of desiccant silica-gel wastes for the mechanical and microstructural performances of self-compacting mortars
Yılmaz, Tekin
The existing exploratory focuses to examine the effect of relocating ordinary Portland cement (OPC) by divergent proportions (2.5–15 %, by vol.) of desiccant silica-gel waste (DSGW) on the strength/durability/microstructural traits of self-compacting mortars (SCMs). A large experimental programme comprising unconfined compressive- (UCS: 7/28/56/90 days) and flexural-strength (FS: 7/28/56/90 days), freeze-thaw (F-T: 50/100 cycles), sorptivity (Sp: 28 days), porosity (PT: 28 days) and scanning electron microscope (SEM: 28 days) tests was conducted on the fabricated SCMs. From the gathered findings, the replacing OPC by 10 % DSGW, compared to the Control, was detected to signify the most efficacious contribution on SCMs' strength (UCS/FS = +15.2/12.3 %), durability (UCS/FS-losses after 50 and 100 F-T = −4.7/−6.1 % and − 10.0/−12.7 %) behavior, which is in tune with the ameliorated microstructure (Sp = −35.2 %, PT = −19.2 % and SEM = higher C-S-H gel, less micro-crack).
- MakaleAçık Erişim2024Effect of White-Portland cement containing micro and nano silica on the mechanical and freeze-thaw properties of self compacting mortars
Etli, Serkan; Yılmaz, Tekin; Hansu, Osman
This study concentrated to investigate the influences of white-Portland cement (W-PC) containing silica fume (SF: micro-silica (µSi) and nano-silica (nSi)) as replacement (2–4 wt%) on mechanical (strength and durability), physical and microstructural behaviors of self-compacting mortars (SCMs) fabricated at 0.48–0.63 w/b ratios. In keeping with these purposes, besides of carrying out the workability (mini-slump flow: M−SF and V-funnel: V-F) experiments of SCMs, the mechanical and microstructural tests implemented were: unconfined compressive strength (UCS), flexural strength (FS), freeze–thaw (F-T) and scanning electron microscope (SEM) analysis. The outcomes displayed that, in comparison with the control, replacing W-PC by SF (particularly nSi) enhanced the UCS and FS, resisted against F-T durability by lowering the strength losses in UCS and FS. The ameliorated microstructure resulting in a reduction in the number and/or a narrowing in the size of micro-cracks and pores contributed to generate a more compact and consolidated SCM structure for the improving of strength and durability due of pore-filling effect and superior pozzolanic characteristics of µSi and especially nSi, this in turn reduced the permeability of SCM, which has a significant effect on the strength and durability behaviors of the SCM.
- MakaleYalnız künye2024An efficient Hartley–Ross type estimators of nonsensitive and sensitive variables using robust regression methods in sample surveys
Zaman, Tolga; Shazad, Usman; Yadav, Vinay Kumar
In sample surveys, the problem of outliers is one of the most frequent and widest, whose solution is required to be obtained using statistical techniques. To overcome this problem, various robust regression methods are being developed such as LTS, LMS, LAD, Huber-M, Hample-M, Tukey-M and Huber-MM methods. This article presents the modified Hartley–Ross type ratio estimators to estimate the population mean in sample surveys. The proposed design is taken into account under the two suppositions one is that the study variable is a non-sensitive variable, which means that measurements on it do not embarrass participants in personal interviews and other is the sensitive variable, which means that measurement errors are introduced as a result of a few dishonest responses. The use of scrambling response models helps to reduce these measurement errors to some extent. The proposed estimator is found to be more efficient than the existing classical estimators. A Numerical illustration was performed on a real data set in R-Program Software to support of our findings.
- MakaleAçık Erişim2024Metaverse in tourism education: A mixed method on vision, challenges and extended technology acceptance model
Akyürek, Suat; Genç, Gökhan; Çalık, İsmail; Şengel, Ümit
The metaverse, an emerging educational frontier, presents boundless opportunities and distinct challenges for educators and students alike. This study delves into these aspects within the context of tourism education, employing a mixed-methods approach. It integrates in-depth interviews with 13 tourism academics and a quantitative survey of 268 tourism students. The qualitative data are meticulously coded, and the quantitative data are analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). This research not only conceptually outlines the future benefits of the metaverse, such as enhanced interactive learning and global classroom experiences but also empirically examines its impact on tourism students' engagement and learning outcomes. Key findings highlight both the empowering potential and the infrastructural and accessibility challenges posed by metaverse technology in tourism education. Ultimately, this study provides a holistic view of metaverse-based education's role in advancing the tourism industry, suggesting practical implications for technological adaptation and pedagogical strategies.
- MakaleAçık Erişim2024Geophysical and numerical approaches to solving the mechanisms of landslides triggered by earthquakes: A case study of Kahramanmaraş (6 February, 2023)
Sari, Mahmut
Many landslides occurred in the 11 Turkish provinces affected by the earthquakes centered in Kahramanmaraş in February 2023, and many people lost their lives due to those landslides. To reduce the risks and hazards brought on by landslides induced by earthquakes, it is essential to identify the mechanisms causing landslides to arise in such situations. In this study, the geological strength index and both seismic refraction tomography and electrical resistivity tomography (ERT) geophysical methods were used to determine the failure mechanism of layered sedimentary units defined as flysch (claystone-siltstone-sandstone-marl). The shear strength reduction finite element method (SSR-FEM) was used with the RS2 computer program for model solutions. One of the geophysical methods, ERT, facilitated an interpretation of the cyclic failure mechanism that occurs in flysch, and it was found to be congruent with numerical models. Landslide slip circle depth, water-saturated layers, and resistivity values were determined with the ERT method. Seismic methods were employed to determine the velocity values (Vp, Vs) of the landslip mass. These velocity data, along with the elasticity modulus and Poisson ratios derived from them, were utilized in our numerical model. In the maximum shear strength and horizontal displacement analyses performed on the section line determined before the landslide, the natural state and the situation under the influence of groundwater were examined and the strength reduction factor (SRF) was determined as 1.35 and 1.24, respectively. In an evaluation conducted under the influence of the maximum horizontal ground acceleration (0.22 g) determined by taking into account the seismicity of the study area, it was concluded that instability occurred in the flysches and the SRF value was 0.72. An important finding of this study is that the results of geophysical methods used to determine the lithological properties of sedimentary rock masses and understand the causes of landslides align closely with those of numerical analysis methods, providing high accuracy. These methods also support new approaches, particularly in identifying landslip boundaries and detecting areas with high water saturation. It has been discovered that earthquakes actively contribute to the instability of these kinds of soils.
- MakaleYayıncıda açık erişim2024Gelatin extraction from chicken skin by conventional and Ohmic heating methods and comparison with commercial halal gelatins
Işık, Çiğdem; Parlak, Mahmut Ekrem; Kıraç Demirel, Fatma Tuba; Odabaş, Halil İbrahim; Dağdelen, Adnan Fatih; Yilmaz, Mustafa Tahsin; Taylan, Osman; Sarıcaoğlu, Furkan Türker
Gelatin extraction from chicken skins using ohmic heating (OH) is a promising application in the food industry. In this study, the effects of OH parameters (electric field (5, 10, 15, and 20 V/cm) and extraction time (1, 3, and 5 h)) on the extraction yield, physicochemical, functional, rheological, thermal, and microstructural properties of chicken skin gelatin were investigated, as well as comparison with conventional extraction and commercial halal gelatins. Chicken skin gelatins obtained with OH-assisted extraction showed higher ash content resulting in more turbidity than commercial gelatins. OH parameters significantly increased the gelatin yield, and 1 h of OH treatment revealed the highest gel strength amongst the electric field applications, conventional extracted, and bovine gelatin. The melting and gelation temperatures of chicken skin gelatins were higher than bovine gelatin and OH treatment increased the thermal stability. The amino acid composition significantly changed with OH treatment, and total imino acid content, relating to the gelation properties, increased. Functional properties, water and oil binding, emulsifying, and foaming, of chicken skin gelatin were significantly higher than commercial gelatins, and OH treatment significantly increased these properties. Overall, OH extraction of gelatin from chicken skins could be a better option for less extraction time, higher extraction yield, better functionality, and higher thermal stability compared to conventional extraction. It was concluded that chicken skin gelatins extracted using OH have properties that can be an alternative to commercial gelatins, but further purification processes are required.
- MakaleAçık Erişim2024Comparison of choroidal thickness, superficial and deep retinal vascular indices, and foveal avascular zones: Martial arts athletes vs healthy non-athletes
Genç, Çiğdem Deniz; Yılmaz, Ali Kerim; Kurt, Muhammed Mustafa; Özgür, Gökhan; Aydın, Emre; Yılmaz, Coşkun
Aim: The study aims to compare choroidal thickness, deep and superficial retinal capillary plexuses, and foveal avascular zone (FAZ) parameters in elite martial arts athletes and a healthy sedentary control group. Methods: The study included martial arts athletes (32 individuals, 64 eyes) and healthy sedentary persons (43 individuals with healthy sedentary lifestyles, 86 eyes) aged 18–35 years. In this single non-repeated observational and cross-sectional study, choroidal thickness, superficial and deep retinal capillary plexuses, and FAZ measurements were measured using Swept-source optical coherence tomography angiography (SS-OCTA) and compared between groups. Results: No statistically significant differences were found (p > 0.05) in age, IOP, AL (axial length), and best-corrected visual acuity (BCVA) parameters between groups. There were no statistically significant differences between the groups in choroidal thickness, superficial and deep retinal capillary plexuses, and FAZ parameters determined by the OCTA method (p > 0.05). Conclusion: In our study, we observed that the retinal and choroidal structures of martial art athletes and healthy sedentary individuals were similar. This observation implies that the putative microvascular effects on the choroid and retina in martial arts, especially those based on the anaerobic energy system, may reflect similar outcomes to those observed in individuals with sedentary lifestyles characterized by healthiness.
- MakaleAçık Erişim2024Improving brain tumor classification with combined convolutional neural networks and transfer learning
İncir, Ramazan; Bozkurt, Ferhat
Brain tumors pose a serious threat, causing the deaths of thousands of people worldwide, and can lead to life-threatening consequences when not accurately diagnosed. The classification of brain tumors and the determination of correct treatment strategies are crucial, yet this process encounters various challenges. These tumors originate from different cell types and exhibit diversity in growth rates, histological features, and genetic structures. Some may show similarities at the microscopic level, complicating classification and making diagnosis and treatment challenging. The examination of brain MR images is a widely used method in diagnosing brain tumors. However, occasional misdiagnosis of tumors can lead to ineffective responses to treatments and reduced chances of survival for patients. Traditional machine learning classifiers require manually determined features, which is quite time-consuming. On the other hand, deep learning is highly effective in feature extraction and has recently been widely preferred in classification. In this context, the effectiveness of transfer learning architectures in brain tumor diagnosis was evaluated. Six different transfer learning architectures, including ResNet-50, MobileNet, VGG16, Inception-V3, DenseNet-121, and EfficientNetV2-M, were used in this study. A public MRI dataset was used for model validation and comparison with similar studies. To address the imbalance in the number of images among classes in the dataset, data augmentation techniques such as random rotation were applied during data preprocessing. Experiments revealed that the EfficientNetV2-M model outperformed other architectures with a 98.01% accuracy rate. Additionally, the study aimed to create a new model with more comprehensive feature extraction and generalization ability by combining the advantages of multiple models in different combinations. In this context, combinations of EfficientNetV2-M architecture with Inception-V3 and DenseNet-121 architectures were formed. Through these combinations, a concatenation-based EfficientNetV2-M + Inception-V3 model achieved a 98.41% accuracy value. It was observed that the proposed concatenation-based model outperformed advanced methods in improving medical imaging techniques and patient outcomes.
- MakaleYalnız künye2024Remote sensing and monitoring of water resources: A comparative study of different indices and thresholding methods
Günen, Mehmet Akif; Atasever, Umit Haluk
Water resources are essential for the ecological system and the development of civilization. Water is imperative factor for health preservation and sustaining various human activities, including industrial production, agriculture, and daily life. Remote sensing provides a cost-effective and practical means to detect and monitor water bodies, offers valuable insights into the impact of climatic events on water structures, especially in coastal lake regions. The research primarily utilizes Landsat-9 OLI-2 satellite images to evaluate the effectiveness of various water indices (WRI, NWI, MNDWI, NDWI) in combination with global automatic thresholding methods (K-Means, Zhenzhou's, Adaptive, Intermodes, Prewitt and Mendelsohn's Minimum, Maximum Entropy, Median, Concavity, Percentile, Intermeans, Kittler and Illingworth's Minimum Error, Tsai's Moments, Otsu's, Huang's fuzzy, Triangle, Mean, IsoData, Li's). The study was carried out on Lake Nazik, Lake Iznik, and Lake Beyşehir, which have unique geographical characteristics, and examined the adaptability and robustness of the selected indices and thresholding methods. MNDWI consistently stands out as a robust index for water extraction, delivering accurate results across different thresholding methods in regions all three lakes. As a result of quite extensive analysis, it is obtained that MNDWI and NDWI are reliable choices for water feature extraction in various lake environments, but the specific index should consider the thresholding method and unique lake characteristics. The Minimum thresholding method stands out as the most effective thresholding technique, demonstrating impressive results across different lakes. Specifically, it achieved an average Peak Signal-to-Noise Ratio (PSNR) of 78.97 and Structural Similarity Index (SSIM) of 99.37 for Lake Nazik, 74.08 PSNR and 98.34 SSIM for Lake Iznik, and 63.96 PSNR and 93.61 SSIM for Lake Beyşehir.
- MakaleAçık Erişim2024Thenovel numerical solutions for conformable fractional Kuramoto-Sivashinsky equations by using Cq-HATM and CHPETM
Avit, Özkan; Anac, Halil
The present study used the novel conformable fractional methods to examine the nonlinear Kuramoto-Sivashinsky equations of the conformable fractional derivative. The Kuramoto-Sivashinsky equation is a mathematical model employed to elucidate a diverse range of chemical and physical phenomena, encompassing chemical reaction-diffusion processes, plasma instabilities, viscous flow issues, flame front propagation, and magnetized plasmas. The present inquiry provides an examination of convergence and error for the future scheme. The conformable q-homotopy analysis transform method (Cq-HATM) provides h-curves that illustrate the convergence range of the series solution achieved. In order to validate the effectiveness and suitability of the Cq-HATM, we examine separate instances. In this study, we introduce an application that demonstrates the potential benefits and effectiveness of the proposed approach. Furthermore, an error analysis is performed in order to verify the accuracy of the scheme. Numerical simulations are conducted to validate the precision of the forthcoming approach. The findings obtained from the numerical and graphical analyses are presented in this study. The method provided in this study showcases a notable degree of computational precision and ease in examining and resolving intricate phenomena related to conformable fractional nonlinear partial differential equations within the domains of science and technology.
- MakaleAçık Erişim2024Characterization of cellulose produced by bacteria isolated from different vinegars
Güzel, Melih
Traditional vinegars are naturally produced from sugar- or starch-containing raw materials, through alcoholic fermentation followed by acetic fermentation. Fermentation is a spontaneous and complex process involving interactions between various microorganisms. In this study, we produced vinegar using traditional methods from six fruits: rosehip, pear, fig, wild pear, apple, and plum. Bacteria that produce bacterial cellulose (BC) were isolated from these vinegars and identified. In addition, we investigated the properties of BC produced from these bacteria. The strains isolated from vinegars were identified as Gluconobacter oxydans strain MG2022, Acetobacter tropicalis strain MG2022, Acetobacter fabarum strain MG2022, Komagataeibacter saccharivorans strain MG2022, K. saccharivorans strain EG2022, and Acetobacter lovaniensis strain OD2022. In total, 0.83–2.04 g/L BC was produced and the bacterial strain isolated from pear vinegar yielded the most BC. BC produced by the bacterial strain isolated from wild pear vinegar had the highest thermal stability and crystallinity (87.44 %). Overall, this study shows that different fruits contain different BC-producing bacteria in their natural flora and vinegars obtained from fruits can be used in BC production. Also, different BC-producing bacteria can be isolated from different vinegars, and BC produced by these bacteria might have different properties.