21241 research outputs found
Sort by
Caffeine Habituation, not CYP1A2 Genotype, Modulates the Acute Effect of Caffeine on Exercise-Induced Hemostatic Responses in Adults with Obesity
Get PDFPurpose This study aimed to investigate how genotype and caffeine habituation influence the acute effects of caffeine ingestion on exercise-induced hemostatic responses in individuals with obesity. Methods Using a randomized, double-blind, placebo-controlled crossover design, 40 physically inactive young men with obesity (age, 22.2 ± 2.3 years; BMI, 34.1 ± 2.7 kg/m2) completed two moderate-to-high-intensity concurrent exercise sessions following ingestion of caffeine (3 mg/kg) or placebo. Blood samples were collected at baseline, after exercise, and after 60 minutes of recovery. Statistical analysis was performed by repeated measures MANOVA. Results Acute exercise increased platelet count and aggregation, fibrinogen, F1 + 2, tPA antigen, D-dimer, and clot lysis time, regardless of genotype or caffeine habituation status (P 0.05) but decreased following recovery (P 0.05). Conclusions Moderate-to-high-intensity concurrent exercise induces a transient prothrombotic state in physically inactive individuals with obesity. Acute caffeine supplementation at a moderate dose modulates the hemostatic responses depending on caffeine habituation status rather than CYP1A2 genotype: it exacerbates the prothrombotic response in naïve consumers but attenuates it in habitual consumers. © 2025 Elsevier B.V., All rights reserved
Does propolis have antiviral potential against Myoviridae bacteriophage?
Get PDFThe Myoviridae family of bacteriophages presents challenges for antiviral research owing to their structural complexity and ecological significance. While the antibacterial and antiviral properties of Anatolian propolis have been studied, its activity against Myoviridae bacteriophages has not previously been evaluated. This study provides the first comprehensive evaluation of the effectiveness of Anatolian propolis against the M8AEC16 bacteriophage, which is employed as a model to examine interactions with viral-like particles in a biosafe environment. Using RP-HPLC-UV, we identified high concentrations of the potent antiviral compounds ferulic acid and caffeic acid phenethyl ester (CAPE). The propolis samples' bioactive richness is further underscored by their high antioxidant capacity, measured as 144.51 mu M Trolox/g using the FRAP method. Spot test analysis revealed that a propolis concentration of 18.4 mg/mL eradicated 9.91 log pfu/mL of the bacteriophage, demonstrating its efficacy at minimal concentrations. These results suggest that Anatolian propolis could be used as a natural agent to target viral-like pathogens and reduce oxidative stress. This could contribute to the development of alternative antiviral approaches based on natural products
Certain domains of a new matrix constructed by Euler totient and its summation function
Get PDFWith the aid of the Euler totient function phi and its summation function inverted perpendicular, a new matrix O(phi, inverted perpendicular) = (delta(phi, inverted perpendicular)nk), where delta(phi, inverted perpendicular)(nk) = {(-1)n-k inverted perpendicular(k)/ O-phi(n) , n - 1 <= k <= n, 0, otherwise is constructed to define the domains l(p)(O(phi, inverted perpendicular)), l(infinity)(O(phi, inverted perpendicular)), and l(1)(O(phi, inverted perpendicular)). After obtaining the norms on these domains, it is proved that these spaces are linearly isomorphic to classical ones. Also, their dual spaces are determined. Finally, characterizations of several matrix mappings are stated and proved
The relationship between school principals' servant leadership behaviours and organizational image according to teachers' perceptions
Get PDFBu araştırmanın amacı, öğretmenlerin algılarına göre okul müdürlerinin hizmetkâr liderlik davranışları ile örgütsel imaj arasındaki ilişkiyi incelemektir. Araştırmada nicel araştırma yöntemlerinden ilişkisel tarama modeli kullanılmıştır. Araştırmada veri toplama araçları olarak "Kişisel Bilgi Formu", Ekinci (2015) tarafından geliştirilen "Okul Müdürlerinin Hizmetkâr Liderlik Davranışları Ölçeği" ve Gürbüz (2008) tarafından geliştirilen "Örgütsel İmaj Algısı Ölçeği" kullanılmıştır. Araştırmanın evrenini 2024-2025 eğitim öğretim yılında Düzce il merkezindeki, Milli Eğitim Bakanlığı'na bağlı resmi ve özel ilkokul, ortaokul ve lise kademelerinde görev yapan öğretmenler oluşturmaktadır. Araştırmanın örneklemi ise küme örnekleme yöntemiyle belirlenen 442 öğretmenden oluşmaktadır. Araştırma sonuçlarına göre, öğretmenlerin okul müdürlerinin hizmetkâr liderlik davranışlarına ve örgütsel imaja ilişkin algıları "yüksek" düzeydedir. Hizmetkâr liderlik davranışlarına yönelik algılar, öğretmenlerin hizmet süresi ve eğitim düzeylerine göre anlamlı bir farklılık göstermemekle birlikte; cinsiyet, mesleki kıdem, okul türü ve eğitim kademesi değişkenlerine göre anlamlı farklılık göstermektedir. Örgütsel imaj algılarına ilişkin analizler de benzer şekilde, hizmet süresi ve eğitim düzeyine göre anlamlı bir fark göstermemiş; ancak cinsiyet, mesleki kıdem, okul türü ve eğitim kademesi değişkenlerinde anlamlı farklılıklar ortaya koymuştur. Araştırma sonucunda, öğretmenlerin algılarına göre okul müdürlerinin hizmetkâr liderlik davranışları ile örgütsel imaj arasında pozitif yönde ve orta düzeyde anlamlı bir ilişki elde edilmiştir. Regresyon analizi sonucunda ise okul müdürlerinin hizmetkâr liderlik davranışlarının öğretmenlerin örgütsel imaj algılarını anlamlı bir şekilde yordadığı ve bu oranının %37.8 düzeyinde olduğu tespit edilmiştir. Bu sonuç okul müdürlerinin sergilemiş olduğu hizmetkâr liderlik davranışlarının, öğretmenlerin örgütsel imaj algılarını olumlu yönde etkilediğini göstermektedir.The aim of this study is to examine the relationship between school principals' servant leadership behaviors and organizational image based on teachers' perceptions. A relational survey model, one of the quantitative research methods, was used in the study. As data collection tools, the "Personal Information Form", the "School Principals' Servant Leadership Behavior Scale" developed by Ekinci (2015), and the "Organizational Image Scale" developed by Gürbüz (2008) were used. The study population consisted of teachers working in public and private primary, secondary, and high schools affiliated with the Ministry of National Education in the city center of Düzce during the 2024–2025 academic year. The sample of the study consisted of 442 teachers determined through cluster sampling method. According to the results of the study, teachers' perceptions of school principals' servant leadership behaviors and organizational image were found to be at a "high" level. When evaluating the demographic variables, no statistically significant differences were found in either the school principals' servant leadership behavior scale or the organizational image scale based on the level of education and length of working at the current school. However; significant differences were observed in servant leadership scale with respect to gender, type of school, professional seniority and educational level taught. Similarly, analyses related to organizational image perceptions did not show significant differences based on the level of education and length of working at the current school; however, significant differences were found in the variables of gender, type of school, professional seniority and educational level taught. As a result of the study, a positive and moderate significant relationship was found between school principals' servant leadership behaviors and organizational image according to teachers' perceptions. As a result of the regression analysis, it was determined that the servant leadership behaviors of school principals significantly predict teachers' perceptions of organizational image, explaining 37.8% of the variance. This result indicates that the servant leadership behaviors exhibited by school principals positively influence teachers' perceptions of the organizational image
Climate change-induced migration: Socio-economic dimension and policy recommendations
Get PDFThis study addresses the economic, social, and environmental impacts of climate change-induced migration from a multidimensional perspective. It is emphasized that climate-induced migration is increasing due to natural disasters, agricultural yield losses and resource depletion, which has profound social and economic impacts on migrating individuals and communities. The economic impacts of migration include imbalances in employment, infrastructure deficiencies, and contribution to local economies. The study argues that policies should be developed at national and international level to manage climate change-induced migration in a sustainable manner. Proposed solutions include policies such as education programs, infrastructure investments, and increased climate finance. In this context, understanding the relationship between climate change and migration is considered a critical step for the formulation of global strategies. © 2025 Elsevier B.V., All rights reserved
Biological and Growth Parameters of Short-beaked Garfish Belone svetovidovi from the Black Sea
Get PDFThe age composition and growth parameters of the Short-beaked garfish Belone svetovidovi collected from the Ak & ccedil;akoca coast in the southwestern Black Sea (D & uuml;zce, T & uuml;rkiye) were investigated. A total of 352 B. svetovidovi individuals were collected monthly from January 2022 to December 2022, including 189 females (54.0%) and 163 males (46.0%). When the length-frequency distribution of B. svetovidoviwas analysed, it was found that the length group with the highest number of individuals was the same for both females and males (34.0-34.9 cm), with 35 females and 38 males. The b value in males, females and all individuals was greater than 3, indicating positive allometric growth. The samples of B. svetovidovi individualswere between 1 and 4 years old, with ages 2 and 3 years accounting for 73.54% of female individuals, 80.98% of male individuals and 76.99% of all individuals, respectively. There was no statistically significant difference between the age groups of males and females at ages 1, 2, and 3 while a significant difference was found between 4-year-old males and females (P < 0.05). The Von Bertalanffy growth values were determined as follows: for females, L = 65.501 [1-e(-0.109 (t+2.586))]; for males, L = 66.751 [1-e(-0.108 (t+2.621))]; and for all individuals, L = 66.596 [1-e(-0.108 (t+2.666))]. The mean condition factor values were found to be 0.1090 +/- 0.015 for females, 0.1085 +/- 0.015 for males, and 0.1087 +/- 0.015 for all individuals. The distribution of gonadosomatic index values by gender showed an increase in February-March-September and a decrease in October-December for both females and males. According to the data obtained from the study, the reproductive period for both female and male individuals was identified as the 7-month period from March to September. This study has revealed, for the first time, some reproductive and growth parameters of the ShThe Scientific & Technological Research Council of Turkey (TUBITAK) [TUBITAK-121N777]Scientific & Technological Research Council of Turkey [BAS-IC-TR/1/2022-2023]Bulgarian Academy of SciencesTUBITAKThis research was supported by the Scientific & Technological Research Council of Turkey (TUBITAK-121N777) and Bulgarian Academy of Sciences (BAS-IC-TR/1/2022-2023). The authors thank to TUBITAK for their supports
Using a monophasic fluid loop simulation software for thermal control in spacecraft
Get PDFIn the field of spacecraft technologies, the thermal control system is a vital subsystem that interacts with all other subsystems within a satellite. Creating a satellite thermal control system involves design, analysis and testing processes. Typically, the thermal design and analysis of satellites are performed using commercial software tools. However, during the preliminary design phase, satellite manufacturers often utilize in-house developed software instead. In this study, a monophasic fluid loop simulation software (MFLSS) tool model was developed with 13 nodes to enable quick trade studies, and was tested against ESATAN-TMS software tools to compare temperature predictions. The main goal of employing the monophasic fluid loop simulation software tool is to rapidly estimate temperature values rather than to replace commercial software. The monophasic fluid loop simulation software tool provided satisfactory temperature results compared to ESATAN-TMS, differing by 1.5 degrees C or less.Duzce UniversityThe author thanks to Sheila Christopher-Gokkaya for revising the whole manuscript
The effect of game-based mathematics teaching on achievement and attitude in 8th grade mathematics lesson
Get PDFBu araştırmanın amacı, oyun temelli öğretim yöntemlerinin 8. sınıf matematik dersindeki öğrenci başarıları, bilgi kalıcılığı ve matematiğe yönelik tutumları üzerindeki etkilerini incelemektir. Özellikle soyut matematik kavramlarının somutlaştırılması ve öğrencilerin derse olan motivasyonlarının artırılması açısından geleneksel yöntemlere kıyasla bu yöntemin daha etkili olup olmadığını değerlendirmek, araştırmanın temel hedefidir. Araştırma, Batı Karadeniz'de bir devlet oratokulunda, 2023-2024 eğitim-öğretim yılında öğrenim gören 8. sınıf öğrencilerinin tamamının katılımıyla gerçekleştirilmiştir. Çalışma grubu, deney ve kontrol olmak üzere iki gruba ayrılmıştır. Araştırma yarı deneysel bir desenle tasarlanmış; ön test-son test kontrol gruplu deneysel desen kullanılmıştır. Uygulama süreci 11 hafta sürmüştür. Deney grubunda oyun temelli matematik öğretimine yönelik etkinlikler uygulanmış, kontrol grubunda ise öğretim programı belirlenen süre içerisinde matematik öğretim programının ön gördüğü yöntem ve tekniklerle gerçekleştirilmiştir. Araştırmada, Matematik Başarı Testi, Matematik Tutum Ölçeği ve uygulama sonunda öğrencilerin görüşlerini almak için Yarı Yapılandırılmış Görüşme Formu kullanılmıştır. Elde edilen nicel veriler istatistik paket programı ile nitel veriler ise nitel araştırma analiz programı ile içerik analizi yöntemiyle sistematik bir şekilde analiz edilmiştir. Araştırma sonuçları, oyun temelli öğretim yöntemlerinin matematik başarısı, öğrenme kalıcılığı ve motivasyon üzerinde olumlu etkiler sağladığını göstermiştir. Deney grubu öğrencilerinin başarı ve tutumlarında anlamlı bir artış gözlenmiş, öğrenmenin uzun süreli kalıcılığı desteklendiği tespit edilmiştir. Ayrıca, oyun temelli etkinlikler matematik dersine olan ilgiyi artırmış, kaygıyı azaltmış ve özgüveni geliştirmiştir. Bu yöntemin, soyut matematik kavramlarını anlamayı kolaylaştırarak öğrenme sürecini daha keyifli ve etkili hale getirdiği belirlenmiştir. Geleneksel yöntemlere kıyasla daha başarılı bulunan bu yöntemin, farklı öğrenci gruplarındaki ve diğer derslerdeki uygulanabilirliği ile uzun vadeli etkilerinin araştırılması önerilmektedir.The purpose of this study is to examine the effects of game-based instructional methods on eighth-grade students' academic achievement, knowledge retention, and attitudes toward mathematics. The primary objective of the research is to evaluate whether this method is more effective than traditional approaches, particularly in terms of concretizing abstract mathematical concepts and enhancing students' motivation toward the subject. The study was conducted in a public middle school in the Western Black Sea region during the 2023–2024 academic year, with the participation of all eighth-grade students. The study group was divided into two groups: experimental and control. The research was designed as a quasi-experimental study employing a pre-test and post-test control group experimental design. The implementation process lasted for 11 weeks. In the experimental group, game-based mathematics teaching activities were applied, whereas the control group followed the standard mathematics curriculum using the conventional teaching methods and techniques prescribed by the official program. The study utilized a Mathematics Achievement Test, a Mathematics Attitude Scale, and a Semi-Structured Interview Form to collect students' opinions at the end of the application. The quantitative data were systematically analyzed using a statistical package program, while qualitative data were examined through content analysis using a qualitative research analysis program. The findings of the study indicate that game-based instructional methods have a positive impact on mathematics achievement, knowledge retention, and student motivation. A significant increase was observed in the success and attitudes of students in the experimental group, and it was found that learning was supported for long-term retention. Additionally, game-based activities increased students' interest in mathematics, reduced anxiety, and improved their self-confidence. The study concludes that this method facilitates the comprehension of abstract mathematical concepts, making the learning process more enjoyable and effective. Compared to traditional methods, game-based instruction was found to be more successful. It is recommended that future research explore the applicability of this method in different student groups and other subjects, as well as its long-term effects
Evaluation of patients with decreased general condition and comparing HOTEL, WPS, and REMS for mortality prediction
Get PDFThe emergency department (ED) plays a crucial role in evaluating patients with decreased general condition (DGC). Prompt diagnosis and precise risk stratification enhances clinical care outcomes. This study aimed to reveal which scoring system is better for predicting mortality in patients with DGC. This single-center prospective study was conducted between 1 March 2021 and 1 June 2021 in a tertiary university hospital's ED. All patients presented with DGC were included. The scores assessed upon ED admission for patients include the Hypotension, Oxygen saturation, low Temperature, ECG changes, and Loss of independence, abbreviated as HOTEL score, Rapid Emergency Medicine Score (REMS), and the Worthing Physiological Scoring (WPS). The study aimed to compare the scoring systems to identify which is the best mortality predictor. Independent risk factors for 30-day mortality were analyzed using binary logistic regression and ROC curves to assess the effectiveness of HOTEL, REMS, and WPS scores in predicting mortality. The study was conducted with 137 DGC patients. The median age of patients presented to the ED with DGC was 77 (66.5-87), and 50.4% were male. 52.6% of patients died within one month. Analysis of mortality risk factors revealed that gender, age, day of admission, visit type, home oxygen, urinary catheter use, and speech status were not independent risk factors. For one-month mortality prediction, AUCs were: HOTEL 0.644 (cut-off 1), REMS 0.635 (cut-off 8), WPS 0.547 (cut-off 5). For mechanical ventilation: HOTEL 0.689 (10), REMS 0.790 (10), WPS 0.777 (4). For ICU admission: HOTEL 0.697 (2), REMS 0.770 (9), WPS 0.728 (4). Both the HOTEL and REMS scoring systems have moderate prognostic value in predicting mortality in patients with a DGC. The REMS, and WPS scores are also more helpful in determining the need for intensive care unit admission and mechanical ventilation
Modelling of university students' earthquake knowledge and sustainable earthquake awareness
Get PDFThe purpose of this study is to examine the correlation between earthquake knowledge and sustainable earthquake awareness among university students, using Structural Equation Modeling (SEM) as the analytical framework. The research encompassed 495 university students hailing from a municipality situated along the North Anatolian Fault in Turkey. The participants' responses to the measurement instruments were subjected to SEM analysis. The assessment instruments utilized in this study were the Sustainable Earthquake Awareness Scale and the Earthquake Knowledge Scale. Prior to analysis, the suitability of these scales for factor analysis was ascertained through Kaiser-Meyer-Olkin (KMO) and Bartlett's tests. Subsequently, the theoretical structural model underwent examination via LISREL software. Results derived from the SEM analysis revealed a favorable association between earthquake knowledge and sustainable earthquake awareness among university students. This underscores the critical importance of individuals possessing comprehensive knowledge about earthquakes and maintaining sustained awareness to mitigate potential damages, particularly loss of life, in the event of seismic activity