Coordination between arm and leg movements during locomotion

To evaluate the contrasting dynamical and biomechanical interpretations of the 2:1 frequency coordination between arm and leg movements that occurs at low walking velocities and the 1:1 frequency coordination that occurs at higher walking velocities, the authors conducted an experiment in which they quantified the effect of walking velocity on the stability of the frequency and phase coordination between the individual limb movements. Spectral analyses revealed the presence of 2:1 frequency coordination as a consistent feature of the data in only 3 out of 8 participants at walking velocities ranging from 1.0 to 2.0 km/h, in spite of the fact that the eigenfrequencies of the arms were rather similar across participants. The degree of interlimb coupling, as indexed by weighted coherence and variability of relative phase, was lower for the arm movements and for ipsilateral and diagonal combinations of arm and leg movements than for the leg movements. Furthermore, the coupling between all pairs of limb movements was found to increase with walking velocity, whereas no clear signs were observed that the switches from 2:1 to 1:1 frequency coordination and vice versa were preceded by loss of stability. Therefore, neither a purely biomechanical nor a purely dynamical model is optimally suited to explain these results. Instead, an integrative model involving elements of both approaches seems to be required

Pyrolysed almond shells used as electrodes in microbial electrolysis cell

9 p.The large cost of components used in microbial electrolysis cell (MEC) reactors represents an important limitation that is delaying the commercial implementation of this technology. In this work, we explore the feasibility of using pyrolysed almond shells (PAS) as a material for producing low-cost anodes for use in MEC systems. This was done by comparing the microbial populations that developed on the surface of PAS bioanodes with those present on the carbon felt (CF) bioanodes traditionally used in MECs. Raw almond shells were pyrolysed at three different temperatures, obtaining the best conductive material at the highest temperature (1000 °C). The behaviour of this material was then verified using a single-chamber cell. Subsequently, the main test was carried out using two-chamber cells and the microbial populations extant on each of the bioanodes were analysed. High-throughput sequencing of the 16S rRNA gene for eubacterial populations was carried out in order to compare the microbial communities attached to each type of electrode. The microbial populations on each electrode were also quantified by real-time polymerase chain reaction (realtime PCR) to determine the amount of bacteria capable of growing on the electrodes’surface. The results indicated that the newly developed PAS bioanodes possess a biofilm similar to those found on the surface of traditional CF electrodes. This research was possible thanks to the financial support of the Junta de Castilla y León, and was financed by European Regional Development Funds (LE320P18). C. B. thanks the Spanish Ministerio de Educación, Cultura y Deporte for support in the form of an FPI fellowship grant (Ref #: BES-2016-078329)

Microbial Fuel Cells and Microbial Ecology: Applications in Ruminant Health and Production Research

Microbial fuel cell (MFC) systems employ the catalytic activity of microbes to produce electricity from the oxidation of organic, and in some cases inorganic, substrates. MFC systems have been primarily explored for their use in bioremediation and bioenergy applications; however, these systems also offer a unique strategy for the cultivation of synergistic microbial communities. It has been hypothesized that the mechanism(s) of microbial electron transfer that enable electricity production in MFCs may be a cooperative strategy within mixed microbial consortia that is associated with, or is an alternative to, interspecies hydrogen (H2) transfer. Microbial fermentation processes and methanogenesis in ruminant animals are highly dependent on the consumption and production of H2in the rumen. Given the crucial role that H2 plays in ruminant digestion, it is desirable to understand the microbial relationships that control H2 partial pressures within the rumen; MFCs may serve as unique tools for studying this complex ecological system. Further, MFC systems offer a novel approach to studying biofilms that form under different redox conditions and may be applied to achieve a greater understanding of how microbial biofilms impact animal health. Here, we present a brief summary of the efforts made towards understanding rumen microbial ecology, microbial biofilms related to animal health, and how MFCs may be further applied in ruminant research

Oxalate degradation in a bioelectrochemical system: reactor performance and microbial community characterization

The aim of this work was to investigate the feasibility of using oxalate at the anode in a continuous reactor. Complete oxalate removal was observed, albeit at a maximum coulombic efficiency of 33.9. ±. 0.4%. At the cathode side, there was an increase in pH from 8 to 11 showing production of caustic. Analysis of the microbial community demonstrated a clear shift during reactor start-up, resulting in enrichment of microorganisms belonging to Bacteroidetes, Firmicutes, Mollicutes, and β and γ-Proteobacteria. Methane was produced throughout the experiment; Archaea belonging to the Methanosarcinacea, Methanomicrobiaceae and Methanosaetaceae were identified as key representatives

Microbial electrosynthesis: From electricity to biofuels and biochemicals

Electricity is one of the most widely available forms of energy and can be produced abundantly and sustainably. Microbial electrosynthesis is a new research field, in which renewable electricity can be used to drive microbial production processes. This allows commodity chemicals to be produced by electrically tapping into the plethora of useful biofuels and biochemicals that microorganisms can make