Düzce Üniversitesi Kurumsal Akademik Arşivi
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Güncel Gönderiler
Age and growth of the needlefish, Tylosurus imperialis (Rafinesque, 1810) from the Levantine coast, North-Eastern Mediterranean
(Univ Oradea Publ House, 2025) Erguden, Deniz; Turan, Cemal; Ivanova, Petya Pavlova; Dogdu, Servet Ahmet; Raykov, Violin Stoyanov; Yankova, Maria; Yaglioglu, Deniz
The present study is the first to determine the age and growth parameters of the needlefish Tylosurus imperialis in the Northeastern Mediterranean. A total of 320 specimens of T. imperialis were caught by gill nets from Turkish coasts (Iskenderun Bay) in the Northeastern Mediterranean between October 2020 and September 2021. The maximum age was 5 years for both sexes combined, and the age group 3-4 comprised 77.5 % of the samples. The total length distribution of T. imperialis was 60 to 109 cm, and the weight distribution was 309 to 1985 g. The b value was between 3.20 and 3.31 for females and males, respectively. The parameter b from the length-weight relationship characterizes a positive allometric growth. Growth equations were calculated as W=0.0006xL(3.2026) (R-2= 0.912) for females, W=0.0004xL(3.3163) (R-2= 0.896) for males, and W= 0.0005xL(3.2456) (R-2=0.904) for all specimens. Von Bertalanffy growth parameters were L-infinity= 139.29 cm, K= 0.119 year(-1), t(0)= -1.819 year for females, L-infinity= 138.50 cm, K= 0.113 year(-1), t(0)= -1.834 year for males and L-infinity= 138.33 cm, K= 0.112 year(-1), t(0)= -1.839 year for all specimens. The spawning period of T. imperialis was determined to be between April and August for both sexes. This data will be useful for the fisheries management of needlefish stocks in our study area and elsewhere.
THE INFLUENCE OF SPORTS HOTEL EMPLOYEES'POLITICAL SKILL ON ROLE STRESS: THE MODERATING ROLE OF SELF-EFFICACY
(Revista Iberoamericana Psicologia Ejercicio & Deporte, 2024) Ongel, Gokten; Taskiran, Erkan; Celik, Guelsah Gencer
Political skill is one of the most important personal resources that employees have. The presence of political skill can cause employees to manage situations such as conflict, ambiguity and overload caused by their roles more effectively. In addition, depending on whether self-efficacy is high or low, the strength of the influence between the relevant variables may increase or decrease. In this context, the study's main purpose is to investigate the moderating role of self-efficacy in the effect of political skill on employees' role stress. The study population of the study consists of those working in sports tourism hotels. The data obtained from 308 sports tourism hotel employees were analyzed with the help of SPSS and Smart PLS programs. According to the findings, it was determined that political skill did not significantly negatively affect role stress and its sub-dimensions, such as role conflict, role overload and role ambiguity. However, when the analysis was made on the moderating role variable, it was revealed that self-efficacy had a moderating role in the effect of political skill on role conflict and role overload among the sub-dimensions of role stress. The findings were discussed in the last part of the study, and suggestions for future research were presented.
EFFECTS OF LITHOSPERMIC ACID SUPPLEMENTATION AGAINST ACUTE EXERCISE-INDUCED OXIDATIVE STRESS IN RATS
(Nobel Ilac, 2024) Coknaz, Hakki; Karaoglan, Esen Sezen; Ozgen, Ufuk
Objective: The aim of the study was to investigate whether lithospermic acid (LSA), a naturally derived polyphenolic compound, supplementation could prevent acute exercise- induced oxidative damage to skeletal muscle tissue in the rats. Material and Method: Rats were randomly selected and divided into three groups (n= 7/group): Group 1Control group (non-exercise, UT), Group 2- Exercise group (exercise, T) and Group 3- Exercise+lithospermic acid group (exercise+lithospermic acid, T/LSA). At the end of the exercise protocol, the samples were removed from the right leg quadriceps muscle. Malondialdehyde (MDA), myeloperoxidase (MPO), glutathione (GSH) and superoxide dismutase (SOD) levels were measured in the muscle samples. Result: Compared to the UT group, malondialdehyde (MDA) and myeloperoxidase (MPO) activity levels in the muscle tissue of the T group significantly increased (p<0.001). MDA and MPO activity levels significantly decreased in the T/LSA group compared to the T group (p<0.05). Glutathione (GSH) and superoxide dismutase (SOD) activity levels significantly decreased in the T group compared to the UT group (p<0.05). GSH and SOD activity levels in muscle tissue significantly increased in the T/LSA group compared to the T group (p<0.05). No significant difference was found in MDA, MPO, GSH, and SOD levels between the UT group and T/LSA group (p>0.05). Conclusion: In conclusion, our study shows that oxidative activity levels in the muscle tissue of the T/LSA group decreased significantly in skeletal muscle-induced acute exercise in rats, so it can be considered that lithospermic acid has a protective effect against oxidative damage.
In Vitro Research on Antimicrobial Activity of Native Anatolian Honey Bee Products against Paenibacillus larvae Strains
(Tarbiat Modares Univ, 2025) Sonmez, Emine; Kekecoglu, Meral; Bozdeveci, Arif; Karaoglu, Sengul Alapy
Worldwide, one of the most damaging diseases in beekeeping is American Foulbrood (AFB). The causative agent of the disease is Paenibacillus larvae, which can remain in spore form in the environment for decades and does not lose its virulence. In the management of this disease, it is inevitable to find an alternative method to the use of antibiotics and burning the hives. In this study, after determining the Total Phenolic (TPC) and Total Flavonoid Contents (TFC) of seven different Anatolian honey bee products (bee venom, bee bread, pollen, royal jelly, propolis, queen bee larvae, drone brood larvae), in vitro antimicrobial activities of these products against two different P. larvae strains were tested. As a result of Folin-Ciocalteu and AlCl3 colorimetric methods, there were significant differences between the samples, and the highest content values were obtained from the propolis samples. The antimicrobial activity results showed that, P. larvae strains were susceptible to all bee products, except queen bee larvae and drone brood larvae. The most significant inhibition was obtained from Anatolian bee venom with the lowest MIC dose 6.25 mu g mL(-1), Bacterial strains showed susceptibility to Anatolian beebread with an effective dose of 7.81 mu g mL(-1) following bee venom. This study is an important first step in identifying new active compounds for the use of in-hive natural products in the development of new preventive treatments against AFB disease, alternative to conventional antibiotic treatments.
ON GENERALIZED CONFORMABLE FRACTIONAL CALCULUS ON TIME SCALES WITH APPLICATION TO A FRACTIONAL NONLOCAL THERMISTOR PROBLEM
(Georgian Natl Acad Sciences, 2025) Bendouma, Bouharket; Sarikaya, Mehmet Zeki
In this paper, we give a new general definition of conformable fractional derivative and integral on time scales, and study some of their important classical properties. As an application, the existence of solutions for the conformable fractional nonlo cal thermistor problem on time scales is studied by using the Banach contraction principle and Schauder's fixed point theorem.
