Brain energy metabolism actively regulates synaptic transmission and activity. We have previously shown that acute footshock (FS)-stress induces fast and long-lasting functional and morphological changes at excitatory synapses in prefrontal cortex (PFC). Here, we asked whether FS-stress increased energy metabolism in PFC, and modified related cognitive functions. Using positron emission tomography (PET), we found that FS-stress induced a redistribution of glucose metabolism in the brain, with relative decrease of [18F]FDG uptake in ventro-caudal regions and increase in dorso-rostral ones. Absolute [18F]FDG uptake was inversely correlated with serum corticosterone. Increased specific hexokinase activity was also measured in purified PFC synaptosomes (but not in total extract) of FS-stressed rats, which positively correlated with 2-Deoxy [3H] glucose uptake by synaptosomes. In line with increased synaptic energy demand, using an electron microscopy-based stereological approach, we found that acute stress induced a redistribution of mitochondria at excitatory synapses, together with an increase in their volume. The fast functional and metabolic activation of PFC induced by acute stress, was accompanied by rapid and sustained alterations of working memory performance in delayed response to T-maze test. Taken together, the present data suggest that acute stress increases energy consumption at PFC synaptic terminals and alters working memory.
The increasing flow of immigrants into Europe over the last decade has generated a range of considerations in the policy agenda of many receiving countries. One of the main considerations for policymakers and public opinion alike is whether immigrants contribute their 'fair' share to their host country's tax and welfare system. In this paper, we assess the net fiscal impact of intra-EU and extra-EU migration in 27 European Union (EU) Member States. We find that migrants in the EU, on average, contribute more than natives to welfare states. However, when we take an age-specific lifecycle perspective, we find that natives generally show a higher net fiscal contribution than both groups of migrants. Among migrants, extra-EU migrants contribute less than intra-EU migrants. We then use a demographic microsimulation model to project the potential net fiscal impact of migration in the EU into the future. We show that despite the fact that intra-EU migration contributes to reduce the strong negative impact of population ageing, its contribution is not sufficient to offset the negative fiscal consequences.
In this work, Combination of Uniform and shifted Binomial random variables (CUB) models were used to understand the role played by liking/disliking toward the sensory meat characteristics and the uncertainty of the respondents. The detection of significant similarities and differences among sensory evaluations was proposed by comparing the parameters estimated by CUB models with the aid of multidimensional scaling (MDS). The MDS approach was also proposed to confirm the presence of the two latent variables -feeling and uncertaintyestimated by CUB models. In particular, the sensory characteristics of a conventional hamburger and a new one produced from dairy cattle at the end of their milk production, properly mixed with chicken and turkey meat were evaluated and compared. This approach resulted useful to understand which hamburger was preferred and why. In particular, the results showed a good level of acceptance for both hamburgers, with a slight preference toward the new product in terms of feeling and uncertainty. The outcomes of the analysis also provided indications to meat producers oriented to exploiting dairy cattle for slaughter and could give suggestions for bottom-up sustainable food policy implications.
PRACTICAL APPLICATIONSIn this study, an integrated approach based on CUB models is proposed to evaluate and compare the sensory characteristics of a conventional hamburger and a new one produced from dairy cattle. The conclusions achieved suggested that this approach can be seen as a successful attempt to evaluate consumer acceptability toward a new food product. The results also confirm the importance of consumer-insight in the innovation process. In particular, the proposed approach allowed integrating the sensory evaluation with marketing processes and efficiently targeting product development activities. Finally, the experimental findings of the current study can be considered an opportunity to valorize livestock production and reduce the environmental impact.
As barreiras naturais à regeneração requer intervenções humanas que facilitem e restaurem a funcionalidade dos processos ecossistêmicos em ambientes florestais, como o aporte de biomassa que é responsável pela manutenção da fertilidade e atividade dos organismos do solo. Com isso, o objetivo deste trabalho é avaliar o efeito da revegetação florestal no aporte de serrapilheira em uma área degradada em Seropédica, Rio de Janeiro. O trabalho foi feito em um local degradado, onde em 1994 uma área foi promovido a revegetação com espécies arbóreas no sistema de plantio adensado, e em outra área manteve-se a regeneração natural (testemunha). Em 2000, em cada área, foram implantados aleatoriamente três parcelas de 25m2 contendo 12 coletores no total, sendo o aporte de serrapilheira monitorado por um ano. O material coletado foi triado em folhas, ramos e material reprodutivo, seco em estufa e pesado. Com seis anos, o sistema adensado de revegetação implantado na área degradada em questão foi eficiente em promover um incremento no aporte de biomassa vegetal e propágulos reprodutivos, o que demostra a existência de barreiras à regeneração natural e a necessidade da interveção humana para reverter antigas práticas degradadoras.
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