Effect of sulfate and iron (III) on LCFA degradation by a methanogenic community

[Excerpt] Under anaerobic conditions long chain fatty acids (LCFA) can be converted to methane by syntrophic bacteria and methanogenic archaea. LCFA degradation was also reported in the presence of alternative hydrogenotrophic partners, such as sulfate-reducing bacteria (SRB) and iron-reducing bacteria (IRB), which generally show higher affinity for H2 than methanogens and are more resistant to LCFA [1,2,3]. Their presence in a microbial culture degrading LCFA can be advantageous to reduce LCFA toxicity towards methanogens, although high concentrations of external electron acceptor (EEA) can lead to outcompetition of methanogens and cease methane production. In this work, we tested the effect of adding sub-stoichiometric concentrations of sulfate and iron(III) to methanogenic communities degrading LCFA. (...)

Predicting harsh discipline in at-risk mothers: the moderating effect of socioeconomic deprivation severity

Socioeconomic disadvantage is an important predictor of maternal harsh discipline, but few studies have examined risk mechanisms for harsh parenting within disadvantaged samples. In the present study, parenting stress, family conflict, and child difficult temperament are examined as predictors of maternal harsh discipline among a group of 58 mothers from socioeconomically disadvantaged backgrounds and their young children between the ages of 1- to 4-years-old. Maternal harsh discipline was measured using standardized observations, and mothers reported on parenting stress, family conflict, and child temperament. Severity of socioeconomic deprivation was included as a moderator in these associations. Results showed that parenting stress and family conflict predicted maternal harsh discipline, but only in the most severely deprived families. These findings extend prior research on the processes through which socioeconomic deprivation severity and family functioning impact maternal harsh discipline within a high-risk sample of low-income families. They suggest that the spillover of negative parental functioning into parent–child interactions is particularly likely under conditions of substantial socioeconomic deprivation. Severity of socioeconomic stress seems to undermine maternal adaptive forms of coping, resulting in harsh disciplining practices. Intervention efforts aimed at improving parenting and family relations, as well as an adaptive coping style assume especial relevance.

State of the art and open questions on cathode preparation based on carbon coated lithium iron phosphate

One important component with particular relevance in battery performance is the cathode, being one of the main responsible elements for cell capacity and cycle life. Carbon coated lithium iron phosphate, C-LiFePO4, active material is one of the most promising cathode materials for the next generation of large scale lithium ion battery applications and strong research efforts are being devoted to it, due to its excellent characteristics, including high capacity, ~170 mAh/g, and safety. This review summarizes the main developments on C-LiFePO4 based cathode film preparation and performance. The effect of the binder, conductive additive, relationship between active material-binder-conductive additive and drying step, in the electrode film fabrication and performance is presented and discussed. Finally, after the presentation of the cell types fabricated with C-LiFePO4 active material and their performance, some conclusions and guidelines for further investigations are outlined.

The Warburg effect in mycobacterial granulomas is dependent on the recruitment and activation of macrophages by interferon-γ

Granulomas are the hallmark of mycobacterial disease. Here, we demonstrate that both the cell recruitment and the increased glucose consumption in granulomatous infiltrates during Mycobacterium avium infection are highly dependent on interferon-y (IFN-y). Mycobacterium avium-infected mice lacking IFN-y signalling failed to developed significant inflammatory infiltrations and lacked the characteristic uptake of the glucose analogue fluorine-18-fluorodeoxyglucose (FDG). To assess the role of macrophages in glucose uptake we infected mice with a selective impairment of IFN-y signalling in the macrophage lineage (MIIG mice). Although only a partial reduction of the granulomatous areas was observed in infected MIIG mice, the insensitivity of macrophages to IFN-y reduced the accumulation of FDG. In vivo, ex vivo and in vitro assays showed that macrophage activated by IFN-y displayed increased rates of glucose uptake and in vitro studies showed also that they had increased lactate production and increased expression of key glycolytic enzymes. Overall, our results show that the activation of macrophages by IFN-y is responsible for the Warburg effect observed in organs infected with M. avium.

Determination of the importance of iron acquisition for Staphylococcus epidermidis biofilm survival in human blood

Dissertação de mestrado em Bioengenharia