Aydın Adnan Menderes University
Recent publications
While the demand for open and distance education is increasing, it also faces high dropout rates. The reasons and solutions for student dropouts need considerable attention. This study aims to uncover the reasons for student dropouts considering the perspective of students, field experts, instructors, administrators, and support staff. Data from semi-structured interviews with 40 participants revealed that students decide to drop out mainly due to four main reasons: internal reasons, external reasons, student characteristics, and student skills. These reasons include 37 sub-factors such as academic integration, social integration, financial status, personality, and self-regulation. The sub-factors and selected quotations from the interviews are presented in the findings. According to the results, administrators, field experts, instructors, and support staff are not aware of all the dropout reasons. The results of this research are believed to guide researchers, practitioners, and administrators in enhancing the quality of open and distance education.
The effects of low partial pressures of oxygen (pO2) on metabolism and fermentation-related gene expression of 'Empire', 'Jonagold' and, 'Fuji' apples have been investigated. Fruit were stored in 0.5, 1.0, and 1.5 kPa O2 (with 1 kPa CO2) at 0.5 °C for up to 6 months. During storage the lowest internal ethylene concentrations were observed in the 0.5 kPa O2 for ‘Empire’ and ‘Fuji’, but the pO2 did not affect those of ‘Jonagold’. pO2 did not affect flesh firmness of ‘Empire’ and ‘Fuji’ because little softening occurred in pO2, but for ‘Jonagold’ firmness was inversely related to pO2. In general, fermentation increased during storage in 0.5 kPa O2 but not in 1.5 kPa O2. However, 0.5 kPa O2 led to up-regulation of MdPDC2 and MdADH1 and down-regulation of MdADH3 in ‘Empire’ and ‘Fuji’, while expression levels of these genes at all pO2 in ‘Jonagold’ were similar. Metabolic responses to pO2 were affected by genetic background. We observed that regulation of MdADH1 is a key factor in control of ethanol accumulation of 'Empire' and 'Fuji' apples. On the other hand, MdADH1 in 'Jonagold' may be associated with stress tolerance to low O2 rather than with fermentation product biosynthesis.
In this study, scour due to an unconfined propeller water jet on homogeneous clay-sand mixtures was investigated experimentally. A total of 9 tests were conducted for the sand bed and 18 tests were carried out for the sand-clay mixture bed. Since clay contents (p) of 0, 5 and 10% by weight were used in the experiments, scour in poorly cohesive sand-clay mixture bed was taken into account. Propeller diameters (Dp) were 0.06 and 0.09 m. Dimensionless propeller heights (y0/Dp) were defined as 1.67, 1.11, 1.0. The increase in clay content causes a decrease in the scour depth and changes the formation of scour profiles. The parameters y0/Dp, F0 (densimetric Froude number), p were found to have significant effects on the behavior of clay-sand mixtures. Considering the test results, equations were proposed to estimate the maximum depth and length of the scour hole formed in the equilibrium condition. In addition, by modifying the equation proposed by Hong et al. (2013), a new equation is proposed for the estimation of temporal maximum scour depth due to the propeller water jet on the sand and weakly cohesive sand-clay mixture beds.
In this study, gold nanoparticles (AuNPs) as a zero-dimensional nanomaterial and TiS2 nanosheets as a two-dimensional material and their composite were prepared and characterized. These AuNPs-TiS2 nanocomposites interacted with uricase enzyme and NafionTM and used to modify the working electrode of the Screen-Printed Electrode (SPE). This prepared nanocomposite modified biosensor was used for the determination of uric acid. Transmission electron microscopy (TEM) photos of the resulting nanocomposite showed that AuNPs were dispersed into TiS2 nanosheets without aggregation. It was observed that the enzyme biosensor with the composite modification offered a wide measurement range (5-2000 µM) and exhibited low LOD (0.18 µM). The prepared uric acid biosensor has high sensitivity, low Km value, and fascinating storage stability. This uric acid biosensor showed high selectivity towards uric acid in the presence of urea, cysteine, glucose, and ascorbic acid. Additionally, this biosensor was successfully used for the determination of uric acid in commercial human serum with high recovery. This study revealed that the use of nanocomposites in biosensor design will yield impressive results.
Introduction: Measurement uncertainty is a non-negative parameter that characterizes the distribution of all values appropriate to the measured size and is associated with the measured result. In this study, we aimed to compare the results with various suggestions and produce more qualified results by calculating the measurement uncertainties of the immunoassays like fertility hormones, drug concentration tests, cardiac markers, thyroid function tests and tumour markers. Materials and methods: Uncertainty calculation was made in accordance with the top-down approach according to Nordtest guide. The 12-month study of internal and external quality assessment results were used. The parameters of drug concentration tests were performed on the Abbott Architect c8000, other hormones/markers on the i2000 of the same brand. Results: Factors that increased the measurement uncertainty of a test were due to external quality control data. The calculations showed that 13 of 26 parameters satisfied quality requirements. The highest uncertainty value, with 28% belonged to cancer antigen 19-9 test. The lowest value was calculated for prolactin with 8.3%. Dehydroepiandrosterone sulfate and phenytoin performed poorly in terms of measurement uncertainty, although internal and external quality control assessment results were considered favourable for both. Conclusion: It is recommended that the concept of measurement uncertainty, which plays an important role in the total quality performance of the laboratory, should be followed up by the clinical laboratory experts at certain time intervals and should be increased the awareness of clinicians about the subject.
The role of c-KIT receptor in anal sac gland adenocarcinoma (ASGAC) is unclear despite its importance in the development of tumours. In this preliminary study, the expression of c-KIT was investigated in rarely observed canine ASGAC. The potential use of CAM5.2 in distinguishing ASGAC from perianal gland tumours was also evaluated. ASGAC was diagnosed in five out of 25 examined perianal tumours. By immunohistochemistry, cytosolic (abnormal) c-KIT expression was seen in four of the five cases. CAM5.2 immunoreactivity was detected in neoplastic cells of all ASGAC cases examined, whereas it was not evident in any case of perianal gland tumour. The findings suggest that c-KIT expression and its cellular localization may be important in the oncogenesis of ASGAC, and CAM5.2 can be used to distinguish between ASGAC and perianal gland tumours.
Schizophrenia is frequently accompanied with social cognitive disturbances. Cannabis represents one established environmental factor associated with the onset and progression of schizophrenia. The present cross-sectional study aimed to investigate the association of facial emotion recognition (FER) performance with cannabis use in 2039 patients with schizophrenia, 2141 siblings, and 2049 healthy controls (HC). FER performance was measured using the Degraded Facial Affect Recognition Task (DFAR). Better FER performance as indicated by higher DFAR-total scores was associated with lifetime regular cannabis use in schizophrenia (B = 1.36, 95% CI 0.02 to 2.69), siblings (B = 2.17, 95% CI 0.79 to 3.56), and HC (B = 3.10, 95% CI 1.14 to 5.06). No associations were found between DFAR-total and current cannabis use. Patients with schizophrenia who started to use cannabis after the age of 16 showed better FER performance than patients who started earlier (B = 2.50, 95% CI 0.15 to 4.84) and non-users (B = 3.72, 95 CI 1.96 to 5.49). Better FER performance was found also in siblings who started to use cannabis after 16 compared to non-users (B = 2.37, 95% CI 0.58 to 4.16), while HC using cannabis performed better than non-users at DFAR-total regardless of the age at onset. Our findings suggest that lifetime regular cannabis use may be associated with better FER regardless of the psychosis risk, but that FER might be moderated by age at first use in people with higher genetic risk. Longitudinal studies may clarify whether there is a cause-and-effect relationship between cannabis use and FER performance in psychotic and non-psychotic samples.
IntroductionIn this study, it was aimed to compare the effects of both melatonin and 25-hydroxyvitamin D3, defined as an immune modulator, on laboratory diagnostic criteria parameters and disease activity in patients with systemic lupus erythematosus (SLE).Methods The study included 56 women with SLE and 40 healthy women (control group). Melatonin and 25-hydroxyvitamin D3 levels of patients and healthy individuals included in the study were examined. In addition, leukocytes, lymphocytes, platelets, C3, C4, anti-double-stranded DNA (Anti-dsDNA), antinuclear antibody, and SLE disease activity index (SLEDAI) were analyzed in women with SLE. Patients were divided into four subgroups according to SLEDAI.ResultsMelatonin and 25-hydroxyvitamin D3 levels of women with SLE were lower than healthy women (p < 0.001). Both melatonin and 25-hydroxyvitamin D3 levels were not correlated with laboratory diagnostic criteria parameters. Only 25-hydroxyvitamin D3 levels were correlated with leukocyte levels (p < 0.01). There was no significant difference between the melatonin levels of the subgroups. The 25-hydroxyvitamin D3 levels of the subgroup without disease activity were higher than levels of the subgroups with disease activity (p < 0.05). There was a negative correlation between SLEDAI score and 25-hydroxyvitamin D3 levels (p < 0.05).Conclusion Women with SLE had lower melatonin and 25-hydroxyvitamin D3 levels than healthy women. On the other hand, parameters of laboratory diagnostic criteria of SLE disease were not related. Only 25-hydroxyvitamin D3 levels were inversely related leukocyte levels. SLE disease activity was not correlated with melatonin levels but negatively correlated with 25-hydroxyvitamin D3 levels. Key Points • Women with SLE have low levels of melatonin and 25-hydroxyvitamin D3. • Melatonin and 25-hydroxyvitamin D3 levels are not related to the laboratory diagnostic criteria parameters for SLE disease. • Low levels of melatonin and 25-hydroxyvitamin D3 may be a factor in the unbalanced immune system of SLE. • Supplementation of melatonin and 25-hydroxyvitamin D3 may be recommended for women patients with SLE.
Climate conditions throughout the world clearly affect every aspect of the lives of plants, animals, and humans. Platanus orientalis L. (Oriental plane) is an important tree species for the economy, culture, and forest ecosystems. Recent studies indicate that the climatic conditions significantly affect the distribution areas of Platanus orientalis L. This study aims to model the potential geographical distribution of Platanus orientalis L., which has a natural distribution in Turkey, today and in the future. The geographical distribution of Platanus orientalis L. is under pressure from human activities such as intensive agricultural production, changes in riverbanks, and increased urban development and road construction, and its population is in serious decline. The study produced prediction models using presence data belonging to the species, bio-climatic variables and altitude, and the distributions of the species were determined according to two separate global climate change scenarios. The potential distribution areas of Platanus orientalis L. for the periods 2041–2060 and 2081–2100 under the SSP5 4.5 and SSP5 8.5 scenarios were modelled using MaxEnt 3.4.1. The distribution area of the species in Turkey will be negatively affected by climatic changes due to relatively medium and high increases in the temperature. Platanus orientalis L., which is also found in the Mediterranean basin, the region subject to the most intensive climate changes, will face the risk of extinction unless it is able to adapt to these changes. Results on the current and future potential distributions of Platanus orientalis L. in Turkey provide crucial insights into species’ response to climate change, particularly to increases in temperature. Extent and locations of predicted suitable and unchanged areas for the distribution of Platanus orientalis L. can be used for developing strategies in conservation, management, monitoring, and cultivation of Platanus orientalis L. in the face of climate change.
Torquigener flavimaculosus Hardy & Randall (1983) was described based on specimens collected from the Gulf of Aqaba, Gulf of Suez, and Gulf of Aden, which has then penetrated the Mediterranean Sea, becoming one of the most abundant invasive tetraodontids. A comparison of samples collected from the northern Levant coasts of Türkiye between 2007 and 2020 showed that morphometric and meristic characteristics do not fully match either with T. flavimaculosus, or the closely related congeneric species T. hypselogeneion and T. altipinnis. Multivariate analysis carried out by 16 morphometric and six meristic characters did not show any discrimination between the above-mentioned species and exhibited almost identical sequences in genetic analysis. The results strongly suggest that T. flavimaculosus and T. hypselogeneion are conspecific, making the former species a junior synonym of the latter.
Mesenchymal stem cells can be obtained and multiplied from various sources and have a very high capacity to release exosomes. Exosomes are nano-sized extracellular vesicles containing biological signaling molecules. This study aimed to determine the effect of MSC-derived exosomes as a drug delivery system for paclitaxel in cervical cancer cells. In this study, human MSC were isolated from wharton jelly of umbilical cord tissue (WJ-MSC), and cells were characterized by CD44, CD90, CD105, and CD34 staining. Exosomes were released in WJ-MSC cells with serum-starved conditions for 48 hours, and particle sizes and structures were examined with zeta-sizer and TEM. In addition, exosomes CD9, CD63, and CD81 markers were checked by western blot. Paclitaxel was loaded into exosomes (Exo-PAC) by electroporation and then incubated with Hela cervical cancer cells for 24 hours. TGF-β, SMAD, Snail, Slug, β-catenin, Notch, Caspase-3, Caspase-9, Bax, Bcl-2 protein and gene expression levels were analyzed in Hela cells. As a result, low concentration Exo-PAC induced apoptosis, and suppressed epithelial-mesenchymal transition proteins in Hela cells. In this study, it has been demonstrated that WJ-MSCs can be used as drug delivery systems for cervical cancer if exosomes are produced scalably in the future.
This research was carried out with the aim of revealing the genetic differences of 30 cotton varieties from 14 countries using the iPBS-retrotransposon marker method. Genetic differences were determined by using iPBS marker method in PCR for 30 cotton varieties. According to the genetic distance matrix obtained in the NTSYS-pc 2.10e program, the closest genotypes were determined to be AzGR-11468 (Azerbaijan) and Maydos Yerlisi (India), and the similarity value between them was found to be 0.0318. The most distant genotypes were determined to be Hill Cotton 3 (Bangladesh) and Shazbaz (Pakistan), and the similarity value between them was found to be 0.7572. When the dendrogram generated based on the UPGMA method was examined.30 cotton varieties were divided into 2 clades. According to the PCA made in the JMP program, the graphic results and eigen values obtained on the two-dimensional plane also supported these results. The first 3 eigen values explained 85% of the total variance in the population. Overall results suggest that Hill Cotton 3 (Bangladesh) (Gossypium arboreum) and Shazbaz (Pakistan) (Gossypium hirsutum) cultivars, which are the most distant relatives among 30 cotton genotypes, can be used as breeding cultivars in future cotton breeding studies.
CITE was a prospective, noninterventional study in adult patients with chronic immune thrombocytopenia (cITP) treated with eltrombopag under routine clinical care in Asia-Pacific, Middle East, and Turkey. Data to assess eltrombopag usage, compliance, and outcomes were collected from May 2017 to December 2020. Platelet response was defined as platelet count ≥50×103/μL in the absence of rescue medications and splenectomy. Quality of life was evaluated using the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) questionnaire. Noncompliance was defined as the number of missed doses and number of days where the patient did not follow food instructions. A total of 231 patients were enrolled; the median (range) duration of eltrombopag treatment was 484.5 (1-642) days. Compliance to prescribed eltrombopag dose since last routine visit was high at ≥96.0%. Baseline median platelet count was 19.0×103/µL, which increased to ≥50×103/µL at month 2 and mostly fluctuated between 70×103/µL and 100×103/µL thereafter. Median time to first platelet response was 1.05 months (95% confidence interval: 0.92-1.28 months), and the median (interquartile range) maximum duration of platelet response was 193 (57-456) days. FACIT-F scores improved from mean (standard deviation) 34.4 (12.1) at baseline to 38.5 (9.1) at month 18. Adverse events occurred in 50.9% of patients (n=116), the most common being upper respiratory tract infection (8.3%) and headache (6.6%). These findings confirmed effectiveness of eltrombopag treatment in routine practice and reassured that real-world compliance to eltrombopag prescribed doses and dietary instructions in the Asia-Pacific, Middle East, and Turkey were in line with current recommendations.
BACKGROUND Rounded shoulder (RS) posture causes neck and shoulder pathologies. Mechanical correction taping (MCT) is often incorporated into postural corrective therapies; however, its effects on muscle stiffness are unclear. OBJECTIVE We investigated the effect of MCT with different tape fabrics, along with exercise, on upper trapezius and pectoralis minor muscle stiffness and the posture of sedentary workers. DESIGN AND SETTING A randomized controlled study was performed at Aydın Adnan Menderes University, Aydın, Turkey. METHODS The study included 39 workers with RS posture. Two intervention groups (performance tape: PT and classic tape: CT) were taped twice a week and administered a home exercise program for 4 weeks. The control (C) group performed only home exercises. RS was measured using an acromion-testing table (AT), stiffness using shear wave elastography ultrasound, and shoulder angle (SA) using a smartphone application at baseline and 4 weeks. Time and group interactions were determined using 3 × 2 mixed analysis of variance. RESULTS Intragroup analyses revealed a significant main effect of time on AT distance (η² = 0.445) and SA (η² = 0.325) in the PT and C groups (P < 0.05) and left upper trapezius stiffness (η² = 0.287) in the CT and C groups (P < 0.05). In the post hoc analyses, no difference was noted between the groups from baseline to 4 weeks (P > 0.05). CONCLUSION Scapular MCT added to postural exercises did not show any difference between the intervention groups and controls in terms of muscle stiffness and posture in sedentary workers. KEYWORDS (MeSH terms): Posture; Shoulder; Exercise; Photogrammetry AUTHORS’ KEYWORDS: Taping; Scapular correction; Stiffness; Elastography
Accurate knowledge of surface anatomy is essential for physical examination, invasive procedures, and anatomy education. Individual factors such as age make surface landmarks variable so accurate descriptions are needed. The aim of this study is to describe age-related surface landmarks for intrathoracic structures in children. A total of 156 thoracic computed tomography scans of children aged 0–18 years were categorized into six groups, and the associations between major intrathoracic structures and surface landmarks were analyzed. Sternal angle is an accurate surface landmark for the azygos vein-superior vena cava junction in all age groups. However, the aortic arch (except in the 0–1 year group), the bifurcation of the pulmonary trunk and the tracheal bifurcation in those aged 15–18 years were not within this plane. The left brachiocephalic vein was located behind the ipsilateral sternoclavicular joint except in the 1–3 years group, and the right was behind it in children older than 6 years. The apex of heart was at the 5th intercostal space level in the 0–1 and 12–18 years groups; however, it was higher in the other groups. The lower borders of the lungs were at the sixth costal cartilage level in the midclavicular line, eighth intercostal space level in the midaxillary line, and T12 adjacent to the vertebral column in the 15–18 years group; the lower borders were at higher levels in younger children. Defining the variations in surface anatomy by in vivo studies will increase its clinical and pedagogical value.
The general claim that tourism is a promoter of peace has not been a common topic of study in the discipline of International Relations. The purpose of this article is to provide a conceptual overview, based on International Relations theories, concerning whether peace between societies can be attained by means of tourism. To that end, the study evaluates tourism’s potential to promote peace via four theories, namely, neorealism, neoliberalism, constructivism, and the critical theory. According to the findings of the overview, the claim that tourism promotes peace theoretically agrees with the arguments of constructivism and neoliberalism.
SARS-CoV-2, the causative agent of COVID-19, which was officially declared a pandemic by the World Health Organization (WHO) on 11 March 2020, is transmitted from person to person through respiratory droplets and close contact and can cause severe respiratory failure and pneumonia. Currently, while the worldwide COVID-19 pandemic is still ongoing and countries are taking strict precautions to protect populations against infection, the most effective precautions still seem to be social distancing and wearing a mask. The question of how effective masks were in the early stages of the COVID-19 pandemic has been widely discussed, both in public and scientific circles, and the protection of different mask types has been examined. This study aimed to examine the comfort conditions provided by the different mask types to the user during use. For this purpose, single-ply, double-ply, three-ply, cloth, FFP1, FFP2, and FFP3 masks with different standards were examined, with and without a valve. To conduct the experiments, the novel thermal head measurement system, developed within the scope of this study, was used specifically for mask comfort studies. Thanks to the developed measurement system, the thermal resistance and water vapor resistance values of different masks were measured, and their comfort conditions were evaluated. According to the findings, cloth masks provide a comfortable condition, with lower thermal resistance and water vapor resistance values than other masks. In addition, it was observed that surgical masks offer better thermal comfort conditions, although they have lower protection than FFP masks.
The effects of crosslinker and dye type on swelling and S-type adsorption properties of crosslinked polyhydroxamates (CHP) were investigated. CHPs containing N,Nʹ-methylenebisacrylamide (N), or ethylene glycol dimethacrylate (E) were used in the swelling, diffusion, and adsorption experiments in solutions of oxazine dyes such as Brilliant Cresyl Blue, Nile Blue, and Cresyl Violet. Swelling and diffusion parameters of CHPs in dye solutions (such as equilibrium swelling, half time of swelling, swelling value at half time, network parameter, diffusion exponent, and diffusion constant) were calculated. It is understood from the time of swelling to reach equilibrium that CHPs swell very fast. CHP-E in all dyes solutions swelled considerably more than CHP-N. Dye solution diffusion into CHPs was determined to be of non-Fickian character. It has been observed that the swelling properties of hydrogels are highly influenced by the crosslinker type. The adsorption of oxazine dyes onto CHPs is similar to the S-type adsorption in the Giles classification system. When it was seen that the experimental data fit the Sigmoidal 4 parameter equation with a high correlation (r² > 0.995), the use of this equation determined the adsorption parameters such as the highest bonding rate or monolayer coverage, the transition point of the isotherm, the magnitude of the absorbent's absorbability and the slope parameter. Site-size, maximum fractional occupancy, the binding ratio at the transition point, binding constant, the initial binding constant, partition coefficient, and adsorption free energy values were also calculated by using the found adsorption values. Dye adsorption from all dyes solutions to CHP-E is considerably higher than CHP-N. An increasing linear relationship was found between swelling and adsorption. In conclusion, the sigmoidal equation approach can be a useful tool for chemists, chemical, agricultural and environmental engineers, polymer scientists to find the adsorption parameters of polymer adsorbents, and at the same time, it can be said that CHP can be used as a good sorbent in the removal of some chemical agents (such as dye molecules, organic molecules, biologically active molecules).
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3,459 members
Faruk Sendur
  • PRM&Algology
Ayca Ozkul
Onur Yilmaz
  • Department of Animal Science, Biometry and Genetic Section
Ulker Eren
  • Department of Histology-Embryology
Serdar şen
  • Department of Thoracic Surgery
Aydın, Turkey
Head of institution
Prof. Dr. Osman Selçuk Aldemir