Endurance of methanogenic archaea in anaerobic bioreactors treating oleate-based wastewater

Methanogenic archaea are reported as very sensitive to lipids and long chain fatty acids (LCFA). Therefore, in conventional anaerobic processes, methane recovery during LCFA-rich wastewater treatment is usually low. By applying a start-up strategy, based on a sequence of step feeding and reaction cycles, an oleate-rich wastewater was efficiently treated at an organic loading rate of 21 kg COD m(-3) day(-1) (50 % as oleate), showing a methane recovery of 72 %. In the present work, the archaeal community developed in that reactor is investigated using a 16S rRNA gene approach. This is the first time that methanogens present in a bioreactor converting efficiently high loads of LCFA to methane are monitored. Denaturing gradient gel electrophoresis profiling showed that major changes on the archaeal community took place during the bioreactor start-up, where phases of continuous feeding were alternated with batch phases. After the start-up, a stable archaeal community (similarity higher than 84 %) was observed and maintained throughout the continuous operation. This community exhibited high LCFA tolerance and high acetoclastic and hydrogenotrophic activity. Cloning and sequencing results showed that Methanobacterium- and Methanosaeta-like microorganisms prevailed in the system and were able to tolerate and endure during prolonged exposure to high LCFA loads, despite the previously reported LCFA sensitivity of methanogens.This study has been financially supported by FEDER funds through the Operational Competitiveness Programme (COMPETE) and by national funds through the Portuguese Foundation for Science and Technology (FCT) in the frame of the projects FCOMP-01-0124-FEDER-007087 and FCOMP-01-0124-FEDER-014784. Financial support from FCT and the European Social Fund (ESF) through PhD grants SFRH/BD/48960/2008 and SFRH/BD/24256/2005 attributed to Andreia Salvador and Ana Julia Cavaleiro is also acknowledged

Acetic acid stress response of the acidophilic sulfate reducer Acididesulfobacillus acetoxydans

Acid mine drainage (AMD) waters are a severe environmental threat, due to their high metal content and low pH (pH <3). Current technologies treating AMD utilize neutrophilic sulfate-reducing microorganisms (SRMs), but acidophilic SRM could offer advantages. As AMDs are low in organics these processes require electron donor addition, which is often incompletely oxidized into organic acids (e.g., acetic acid). At low pH, acetic acid is undissociated and toxic to microorganisms. We investigated the stress response of the acetotrophic Acididesulfobacillus acetoxydans to acetic acid. A. acetoxydans was cultivated in bioreactors at pH 5.0 (optimum). For stress experiments, triplicate reactors were spiked until 7.5 mM of acetic acid and compared with (non-spiked) triplicate reactors for physiological, transcriptomic, and membrane lipid changes. After acetic acid spiking, the optical density initially dropped, followed by an adaptation phase during which growth resumed at a lower growth rate. Transcriptome analysis revealed a downregulation of genes involved in glutamate and aspartate synthesis following spiking. Membrane lipid analysis revealed a decrease in iso and anteiso fatty acid relative abundance; and an increase of acetyl-CoA as a fatty acid precursor. These adaptations allow A. acetoxydans to detoxify acetic acid, creating milder conditions for other microorganisms in AMD environments

Transboundary water interaction III: contest and compliance

This paper serves international water conflict resolution efforts by examining the ways that states contest hegemonic transboundary water arrangements. The conceptual framework of dynamic transboundary water interaction that it presents integrates theories about change and counter-hegemony to ascertain coercive, leverage, and liberating mechanisms through which contest and transformation of an arrangement occur. While the mechanisms can be active through sociopolitical processes either of compliance or of contest of the arrangement, most transboundary water interaction is found to contain elements of both. The role of power asymmetry is interpreted through classification of intervention strategies that seek to either influence or challenge the arrangements. Coexisting contest and compliance serve to explain in part the stasis on the Jordan and Ganges rivers (where the non-hegemons have in effect consented to the arrangement), as well as the changes on the Tigris and Mekong rivers, and even more rapid changes on the Amu Darya and Nile rivers (where the non-hegemons have confronted power asymmetry through influence and challenge). The framework also stresses how transboundary water events that may appear isolated are more accurately read within the many sociopolitical processes and arrangements they are shaped by. By clarifying the typically murky dynamics of interstate relations over transboundary waters, furthermore, the framework exposes a new suite of entry points for hydro-diplomatic initiatives

Re-cycling paradigms: cell cycle regulation in adult hippocampal neurogenesis and implications for depression

Since adult neurogenesis became a widely accepted phenomenon, much effort has been put in trying to understand the mechanisms involved in its regulation. In addition, the pathophysiology of several neuropsychiatric disorders, such as depression, has been associated with imbalances in adult hippocampal neurogenesis. These imbalances may ultimately reflect alterations at the cell cycle level, as a common mechanism through which intrinsic and extrinsic stimuli interact with the neurogenic niche properties. Thus, the comprehension of these regulatory mechanisms has become of major importance to disclose novel therapeutic targets. In this review, we first present a comprehensive view on the cell cycle components and mechanisms that were identified in the context of the homeostatic adult hippocampal neurogenic niche. Then, we focus on recent work regarding the cell cycle changes and signaling pathways that are responsible for the neurogenesis imbalances observed in neuropathological conditions, with a particular emphasis on depression

Participative Leadership and Organizational Identification in SMEs in the MENA Region: Testing the Roles of CSR Perceptions and Pride in Membership

The aim of this research is to explore the process linking participative leadership to organizational identification. The study examines the relationship between participative leadership and internal CSR perceptions of employees and also investigates the role that pride in membership plays in the affiliation of CSR perceptions with organizational identification. By studying these relationships, the paper aspires to contemplate new presumed mediators in the association of participative leadership with organizational identification as well as determine a possible novel antecedent of employee CSR perceptions. Empirical evidence is provided from data that was collected through a survey distributed to employees working for small- and medium-sized enterprises in three countries in the Middle East and North Africa regions, particularly the United Arab Emirates, Lebanon, and Tunisia. Findings show that participative leadership leads to positive internal CSR perceptions of employees and that these CSR perceptions lead to pride in membership which, in turn, results in organizational identification. Implications of these findings are also discussed

A global experiment on motivating social distancing during the COVID-19 pandemic

Significance Communicating in ways that motivate engagement in social distancing remains a critical global public health priority during the COVID-19 pandemic. This study tested motivational qualities of messages about social distancing (those that promoted choice and agency vs. those that were forceful and shaming) in 25,718 people in 89 countries. The autonomy-supportive message decreased feelings of defying social distancing recommendations relative to the controlling message, and the controlling message increased controlled motivation, a less effective form of motivation, relative to no message. Message type did not impact intentions to socially distance, but people’s existing motivations were related to intentions. Findings were generalizable across a geographically diverse sample and may inform public health communication strategies in this and future global health emergencies. Abstract Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

Effects of methadone on the minimum anesthetic concentration of isoflurane, and its effects on heart rate, blood pressure and ventilation during isoflurane anesthesia in hens (Gallus gallus domesticus)

© 2016 Escobar et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The aim of this study was to measure the temporal effects of intramuscular methadone administration on the minimum anesthetic concentration (MAC) of isoflurane in hens, and to evaluate the effects of the isoflurane-methadone combination on heart rate and rhythm, blood pressure and ventilation. Thirteen healthy adult hens weighing 1.7 ± 0.2 kg were used. The MAC of isoflurane was determined in each individual using the bracketing method. Subsequently, the reduction in isoflurane MAC produced by methadone (3 or 6 mg kg -1 , IM) was determined by the up-and-down method. Stimulation was applied at 15 and 30 minutes, and at 45 minutes if the bird had not moved at 30 minutes. Isoflurane MAC reduction was calculated at each time point using logistic regression. After a washout period, birds were anesthetized with isoflurane and methadone, 6 mg kg -1 IM was administered. Heart rate and rhythm, respiratory rate, blood gas values and invasive blood pressure were measured at 1.0 and 0.7 isoflurane MAC, and during 45 minutes after administration of methadone once birds were anesthetized with 0.7 isoflurane MAC. Fifteen minutes after administration of 3 mg kg -1 of methadone, isoflurane MAC was reduced by 2 (-9 to 13)% [logistic regression estimate (95% Wald confidence interval)]. Administration of 6 mg kg -1 of methadone decreased isoflurane MAC by 29 (11 to 46)%, 27 (-3 to 56)% and 10 (-8 to 28)% after 15,30 and 45 minutes, respectively. Methadone (6 mg kg -1 ) induced atrioventricular block in three animals and ventricular premature contractions in two. Methadone caused an increase in arterial blood pressure and arterial partial pressure of carbon dioxide, while heart rate and pH decreased. Methadone, 6 mg kg -1 IM significantly reduced isoflurane MAC by 30% in hens 15 minutes after administration. At this dose, methadone caused mild respiratory acidosis and increase in systemic blood pressure