Мотивация и ее методы социально-психологического стимулирования

Материалы XVIII Междунар. науч.-техн. конф. студентов, аспирантов и молодых ученых, Гомель, 26–27 апр. 2018 г

Characterisation of anandamide uptake in resting and activated murine cells

Modifying the metabolism of the body’s own endocannabinoids is a novel approach for analgesia. Two key catabolic enzymes are fatty acid amide hydrolase (FAAH) and inflammation-inducible cyclooxygenase 2 (COX-2). The cellular uptake of the key endocannabinoid anandamide (AEA) has been found to be regulated by its FAAH-catalysed intracellular degradation, but COX-2 has not been investigated in this respect. We aimed to find out whether or not COX-2 in an in vitro inflammation setting would be able to gate AEA uptake. To achieve this, C6 cells and Raw 264.7 cells were stimulated with LPS/INF-γ and lysates then analyzed by immunoblot in order to verify COX-2 expression. AEA cellular uptake was quantified using a radioassay with [3H]-AEA. It was found that COX-2 was not inducible in C6 cells using the LPS/INF-γ conditions studied, while it was inducible in Raw 264.7 cells. AEA uptake in the COX-2-induced Raw 264.7 cells was not reduced by inhibitors of this enzyme. FAAH appeared to be down-regulated in the stimulated Raw 264.7 cells, and this was reflected in an overall lower AEA uptake. Our interpretation of the data points to FAAH as gating AEA uptake. Additional experiments are required to validate our findings by verifying significance.

Evaluation of different stable isotope methods to estimate trophic position of perch (Perca fluviatilis) in Swedish lakes

The Water Framework Directive (WFD) requires member states to implement a strategy to meet the environmental quality standards (EQS) set by the WFD for a number of priority substances. Since the EQSs listed in the WFD are derived to protect the most sensitive species in the ecosystem, often top predators or humans, it has been decided that for certain priority substances the quality standards should be compared to a monitoring species with a trophic position (TP) similar to the diet of the most sensitive species. To enable such adjustment require both knowledge about the monitoring species TP in the food web as well as the relationship between contaminant concentration and trophic position. In this study, we focus on finding a suitable method for TP estimates of perch in Swedish lakes by evaluating both traditional stable isotope analysis in bulk samples (BSIA) using different baseline matrices and the more recent development of compound-specific stable isotope analysis in amino acids (CSIA-AA). For this, three representative monitoring lakes were selected in which perch together with potential baseline matrices (bivalves, gastropods and sediment) were sampled. We applied triple-isotope analyses, δ15N, δ13C and δ34S, of bulk material of all sampled matrices, and in addition δ15N in perch using CSIA-AA. Results showed that TP estimates derived from CSIA-AA were significantly (p<0.001) lower compared to all the BSIA-derived methods and further that the BSIA-derived TP estimates using gastropods as a baseline were significantly higher (p<0.001) than all other TP estimates. Since no statistical differences could be detected between TP estimates based on bivalves, sediment or a ‘mixture’ baseline these were assumed to produce similar results and therefore all valid baseline matrices for TP estimates of perch in these three lakes. In the present study we also attempted to adjust mercury contaminant data to a specific TP of 3.5 according to the WFD. The adjustment resulted in significantly different concentration for one of the two tested lakes but did not influence the chemical status classification as all lakes were well above the threshold for mercury in freshwater lakes

Evaluation of different stable isotope methods to estimate trophic position of perch (Perca fluviatilis) in Swedish lakes

The Water Framework Directive (WFD) requires member states to implement a strategy to meet the environmental quality standards (EQS) set by the WFD for a number of priority substances. Since the EQSs listed in the WFD are derived to protect the most sensitive species in the ecosystem, often top predators or humans, it has been decided that for certain priority substances the quality standards should be compared to a monitoring species with a trophic position (TP) similar to the diet of the most sensitive species. To enable such adjustment require both knowledge about the monitoring species TP in the food web as well as the relationship between contaminant concentration and trophic position. In this study, we focus on finding a suitable method for TP estimates of perch in Swedish lakes by evaluating both traditional stable isotope analysis in bulk samples (BSIA) using different baseline matrices and the more recent development of compound-specific stable isotope analysis in amino acids (CSIA-AA). For this, three representative monitoring lakes were selected in which perch together with potential baseline matrices (bivalves, gastropods and sediment) were sampled. We applied triple-isotope analyses, δ15N, δ13C and δ34S, of bulk material of all sampled matrices, and in addition δ15N in perch using CSIA-AA. Results showed that TP estimates derived from CSIA-AA were significantly (p<0.001) lower compared to all the BSIA-derived methods and further that the BSIA-derived TP estimates using gastropods as a baseline were significantly higher (p<0.001) than all other TP estimates. Since no statistical differences could be detected between TP estimates based on bivalves, sediment or a ‘mixture’ baseline these were assumed to produce similar results and therefore all valid baseline matrices for TP estimates of perch in these three lakes. In the present study we also attempted to adjust mercury contaminant data to a specific TP of 3.5 according to the WFD. The adjustment resulted in significantly different concentration for one of the two tested lakes but did not influence the chemical status classification as all lakes were well above the threshold for mercury in freshwater lakes

Utvärdering av stabila isotoper som metod för att uppskatta trofinivå i abborre (Perca fluviatilis) från Svenska sjöar

The Water Framework Directive (WFD) requires member states to implement a strategy to meet the environmental quality standards (EQS) set by the WFD for a number of priority substances. Since the EQSs listed in the WFD are derived to protect the most sensitive species in the ecosystem, often top predators or humans, it has been decided that for certain priority substances the quality standards should be compared to a monitoring species with a trophic position (TP) similar to the diet of the most sensitive species. To enable such adjustment require both knowledge about the monitoring species TP in the food web as well as the relationship between contaminant concentration and trophic position. In this study, we focus on finding a suitable method for TP estimates of perch in Swedish lakes by evaluating both traditional stable isotope analysis in bulk samples (BSIA) using different baseline matrices and the more recent development of compound-specific stable isotope analysis in amino acids (CSIA-AA). For this, three representative monitoring lakes were selected in which perch together with potential baseline matrices (bivalves, gastropods and sediment) were sampled. We applied triple-isotope analyses, d15N, d13C and d34S, of bulk material of all sampled matrices, and in addition d15N in perch using CSIA-AA. Results showed that TP estimates derived from CSIA-AA were significantly (p<0.001) lower compared to all the BSIA-derived methods and further that the BSIA-derived TP estimates using gastropods as a baseline were significantly higher (p<0.001) than all other TP estimates. Since no statistical differences could be detected between TP estimates based on bivalves, sediment or a ‘mixture’ baseline these were assumed to produce similar results and therefore all valid baseline matrices for TP estimates of perch in these three lakes. In the present study we also attempted to adjust mercury contaminant data to a specific TP of 3.5 according to the WFD. The adjustment resulted in significantly different concentration for one of the two tested lakes but did not influence the chemical status classification as all lakes were well above the threshold for mercury in freshwater lakes

Lack of trophic polymorphism despite substantial genetic differentiation in sympatric brown trout (Salmo trutta) populations

Sympatric populations occur in many freshwater fish species; such populations are typically detected through morphological distinctions that are often coupled to food niche and genetic separations. In salmonids, trophic and genetically separate sympatric populations have been reported in landlocked Arctic char, whitefish and brown trout. In Arctic char and brown trout rare cases of sympatric, genetically distinct populations have been detected based on genetic data alone, with no apparent morphological differences, that is cryptic structuring. It remains unknown whether such cryptic, sympatric structuring can be coupled to food niche separation. Here, we perform an extensive screening for trophic divergence of two genetically divergent, seemingly cryptic, sympatric brown trout populations documented to remain in stable sympatry over several decades in two interconnected, tiny mountain lakes in a nature reserve in central Sweden. We investigate body shape, body length, gill raker metrics, breeding status and diet (stomach content analysis and stable isotopes) in these populations. We find small significant differences for body shape, body size and breeding status, and no evidence of food niche separation between these two populations. In contrast, fish in the two lakes differed in body shape, diet, and nitrogen and carbon isotope signatures despite no genetic difference between lakes. These genetically divergent populations apparently coexist using the same food resources and showing the same adaptive plasticity to the local food niches of the two separate lakes. Such observations have not been reported previously but may be more common than recognised as genetic screenings are necessary to detect the structures