8 research outputs found
Interuniversity Online Courses as Possible Approach to Improve Teaching During Crisis: a Ukrainian Case Study
The war launched by Russia has created new challenges for universities, including massive student migration abroad and massive displacement of students within Ukraine from the frontline areas. Many students lost access to quality education or had their studies interrupted by the war. Recognizing these problems, universities are trying to find different solutions. One such approach may be to introduce inter-university online courses that will be recognized by partner universities. In this case study, we analyze the effectiveness of inter-university online courses as an approach to restoring education for students severely affected by the war and as a way to maintain the quality of education in small groups at universities. The online course "Integrated Life Science Course" was taken for analysis, which was taught both to biology students from different universities in Ukraine within the framework of the educational project supported by German Academic Exchange Service (DAAD). Using statistics on course registration and attendance, as well as interview methodology, we assessed students' motivation to participate in this online course, course satisfaction, and learning outcomes, and identified shortcomings and pitfalls to avoid in similar courses. The survey and the results of the final test show that the main motivator for students to register and study at the course was the desire to gain new knowledge for further professional growth. A scholarship was also an important argument to enroll in the course; however, it did not impact the motivation of students to study. The fraction of students that successfully passed the final exam (~70%) was equal in the cohorts that had and had not been awarded scholarships. Thus, the scholarship was not a motivator to complete the course and successfully pass the exam to receive the certificate. Therefore, in order for such courses to be productive and effective, it is necessary to emphasize student motivation during selecting procedure
ALPHA-KETOGLUTARATE PARTIALLY PROTECTS FRUIT FLY DROSOPHILA MELANOGASTER FROM ETHANOL TOXICITY
Alpha-ketoglutarate (AKG) is an important intermediate in Krebs cycle and in metabolism of amino acids. Recently, it was proposed to apply as a dietary supplement to improve overall functional state of living organisms. In particular, AKG was supposed to use under exposure of animals and cell cultures to many toxic agents. In this context, this study aimed to elucidate the ability of dietary AKG to reduce toxic effects of ethanol on development of fruit fly Drosophila melanogaster, which is a popular model subject to research many aspects of biology of higher eukaryotes. For this aim, the effect of sodium salt of AKG on pupation speed of D. melanogaster w1118 on the medium supplemented with different concentrations of ethanol was studied. Ethanol at a low concentration (2%) did not affect the rate of larval pupation, whereas at higher concentrations it significantly delayed fly pupation and showed developmental toxicity reducing a number of total pupae formed. The most toxic developmental effects of ethanol were observed at its highest concentration (15%). The potential mechanisms of protective effects of AKG are discussed
Alpha-ketoglutarate reduces ethanol toxicity in Drosophila melanogaster by enhancing alcohol dehydrogenase activity and antioxidant capacity
Ethanol at low concentrations (<4%) can serve as a food source for fruit fly Drosophila melanogaster, whereas at higher concentrations it may be toxic. In this work, protective effects of dietary alpha-ketoglutarate (AKG) against ethanol toxicity were studied. Food supplementation with 10-mM AKG alleviated toxic effects of 8% ethanol added to food, and improved fly development. Two-day-old adult flies, reared on diet containing both AKG and ethanol, possessed higher alcohol dehydrogenase (ADH) activity as compared with those reared on control diet or diet with ethanol only. Native gel electrophoresis data suggested that this combination diet might promote post-translational modifications of ADH protein with the formation of a highly active ADH form. The ethanol-containing diet led to significantly higher levels of triacylglycerides stored in adult flies, and this parameter was not altered by AKG supplement. The influence of diet on antioxidant defenses was also assessed. In ethanol-fed flies, catalase activity was higher in males and the levels of low molecular mass thiols were unchanged in both sexes compared to control values. Feeding on a mixture of AKG and ethanol did not affect catalase activity but caused a higher level of low molecular mass thiols compared to ethanol-fed flies. It can be concluded that both a stimulation of some components of antioxidant defense and the increase in ADH activity may be responsible for the protective effects of AKG diet supplementation in combination with ethanol. The results suggest that AKG might be useful as a treatment option to neutralize toxic effects of excessive ethanol intake and to improve the physiological state of D. melanog
Dietary alpha-ketoglutarate increases cold tolerance in Drosophila melanogaster and enhances protein pool and antioxidant defense in sex-specific manner
Alpha-ketoglutarate (AKG) is an important intermediate in Krebs cycle which bridges the metabolism of amino acids and carbohydrates. Its effects as a dietary supplement on cold tolerance were studied in Drosophila melanogaster Canton S. Two-day-old adult flies fed at larval and adult stages with AKG at moderate concentrations (5-10 mM) recovered faster from chill coma (0 °C for 15 min or 3 h) than control ones. The beneficial effect of AKG on chill coma recovery was not found at its higher concentrations, which suggests hormetic like action of this keto acid. Time of 50% observed mortality after 2 h recovery from continuous cold exposure (-1 °C for 3-31 h) (LTi50) was higher for flies reared on 10 mM AKG compared with control ones, showing that the diet with AKG enhanced insect cold tolerance. In parallel with enhancement of cold tolerance, dietary AKG improved fly locomotor activity. Metabolic effects of AKG differed partly in males and females. In males fed on AKG, there were no differences in total protein and free amino acid levels, but the total antioxidant capacity, catalase activity and low molecular mass thiol content were higher than in control animals. In females, dietary AKG promoted higher total antioxidant capacity and higher levels of proteins, total amino acids, proline and low molecular mass thiols. The levels of lipid peroxides were lower in both fly sexes reared on AKG as compared with control ones. We conclude that both enhancement of antioxidant system capacity and synthesis of amino acids can be important for AKG-promoted cold tolerance in D. melanogaster. The involvement of AKG in metabolic pathways of Drosophila males and females is discussed
Alpha-ketoglutarate attenuates toxic effects of sodium nitroprusside and hydrogen peroxide in Drosophila melanogaster
The protective effects of dietary alpha-ketoglutarate (AKG) are described that aid fruit flies, Drosophila melanogaster, to resist sodium nitroprusside (SNP) and hydrogen peroxide toxicity. Food supplementation with 10mM AKG alleviated toxic effects of 1mM SNP added to food and improved fly development. Dietary AKG also prevented the increase in levels of oxidative stress markers seen in SNP-reared adult flies. In vitro AKG did not affect the rate of SNP decomposition and did not bind iron and nitrite ions released in this process. Alpha-ketoglutarate also displayed high H2O2-scavenging activity in vitro and efficiently protected adult flies against this compound in combined treatments. Based on the observed antioxidant activity of AKG, it may be suggested that the antioxidant mode of AKG action (apart from its cyanide-binding capability) may be used to prevent the toxic effects of SNP and improve general physiological state of D. melanogaster and other animals and humans
Dietary alpha-ketoglutarate promotes higher protein and lower triacylglyceride levels and induces oxidative stress in larvae and young adults but not in middle-aged Drosophila melanogaster
Alpha-ketoglutarate (AKG) is involved in multiple metabolic and regulatory pathways. In this work, the effects of AKG-supplemented diets on selected physiological responses and metabolic processes, including metabolism of reactive oxygen species, was assessed in larvae and adult (both 2 and 24 days old) Drosophila melanogaster. Dietary supplementation with AKG resulted in dose-dependent effects on larval development, body composition and antioxidant status of third instar larvae. Larvae and young (2 days post-eclosion) adult females fed on AKG shared similar metabolic changes such as higher total protein levels, lower triacylglyceride levels and higher values for oxidative stress indices, namely lipid peroxides and low molecular mass thiols. The latter indicated the development of oxidative stress which, in turn, may induce adaptive responses that can explain the higher resistance of AKG-fed young females to heat shock and hydrogen peroxide exposure. In contrast to young flies, middle-aged females (24 days) on AKG-containing diet possessed higher total protein, glucose and triacylglyceride levels, whereas oxidative stress parameters were virtually the same as compared with control females of the same age. In parallel, females fed an AKG-supplemented diet showed lower fecundity, higher heat shock resistance but no change in oxidative stress resistance at middle age which in combination with levels of protein, glucose, and triacylglycerides can be considered as potentially beneficial AKG effects for aging organisms. To our best knowledge, this is the first study on age-matched AKG influence on animals' organism which shows that Drosophila may be used as a model for previous quick study in cost-efficient manner age-related AKG effects in mammals and humans