Identification of bacteria associated with Dinoflagellates (Dinophyceae) Alexandrium spp. using tyramide signal amplification fluorescent in situ hybridization and confocal microscopy

In the marine environment, phytoplankton and bacterioplankton can be physically associated. Such association has recently been hypothesized to be involved in the toxicity of the dinoflagellate genus Alexandrium. However, the methods, which have been used so far to identify, localize, and quantify bacteria associated with phytoplankton, are either destructive, time consuming, or lack precision. In the present study we combined tyramide signal amplification–fluorescent in situ hybridization (TSA-FISH) with confocal microscopy to determine the physical association of dinoflagellate cells with bacteria. Dinoflagellate attached microflora was successfully identified with TSA-FISH, whereas FISH using monolabeled probes failed to detect bacteria, because of the dinoflagellate autofluorescence. Bacteria attached to entire dinoflagellates were further localized and distinguished from those attached to empty theca, by using calcofluor and DAPI, two fluorochromes that stain dinoflagellate theca and DNA, respectively. The contribution of specific bacterial taxa of attached microflora was assessed by double hybridization. Endocytoplasmic and endonuclear bacteria were successfully identified in the nonthecate dinoflagellate Gyrodinium instriatum. In contrast, intracellular bacteria were not observed in either toxic or nontoxic strains of Alexandrium spp. Finally, the method was successfully tested on natural phytoplankton assemblages, suggesting that this combination of techniques could prove a useful tool for the simultaneous identification, localization, and quantification of bacteria physically associated with dinoflagellates and more generally with phytoplankton.

Enhancing the student experience by embedding personal tutoring in the curriculum

This paper evaluates an initiative to improve the effectiveness of personal tutoring by embedding it into the curriculum. Structured group tutorials help students make the transition to learning in higher education. These tutorials are delivered within a core module and focus on enabling students to develop study skills, reflect on their learning and plan for their future. The tutor has a role in familiarising students with the practices, norms and skills required for learning at university. The system developed provides a structure and rationale for the interaction of tutors and students, with a clear place and value within the curriculum.

Introducing EbolaCheck: potential for point-of-need infectious disease diagnosis

The 2013–2015 Ebolavirus disease humanitarian crisis has spurred the development of laboratory-free, point-of-care nucleic acid testing solutions. EbolaCheck is an international consortium of public health, academic and biotechnology industry stakeholders aiming to deliver clinical molecular diagnostic standard-of-care testing suitable for the West African milieu within 12 months. In this article, the current status of the EbolaCheck platform is discussed in the context of the current regulatory framework. Presented here are future goals to achieve differential diagnosis of hemorrhagic fever disease from <5-μl of whole blood samples or mucosal biofluids, in a single tube process, under 40 min and with minimal operator training requirements.

Machiavelli’s Walls: The Legacy of Realism in International Relations Theory

In this paper we argue that Niccolò Machiavelli has little to do with Realism in International Relations theory. By concentrating, as Machaivelli did, on the walls that define political relations—both inside and outside the polity—we find his insights deeply rooted in the specific political contexts of Sixteenth century Italy. Others may wish to generalize from them, but Machiavelli did not. In fact, as we show, Machiavelli was mindful of the difficulties of generalizing about walls and acknowledged the dangers political actors faced in navigating between the internal and external walls of the polity. We examine the geopolitical contours of Machiavelli’s walls and seek to demonstrate how morality is present in these historical spaces. In contrast to Realists, Machiavelli was ready and willing to make ethical judgments. We argue that theorists of international politics should exercise care in reaching for Machiavelli as the iconic thinker for making sense of anarchy in world politics. This article concludes by suggesting that the ideology of Machiavellianism has obscured deeper understanding of the particular contexts of Machiavelli’s own world.

Contribution of direct electron transfer mechanisms to overall electron transfer in microbial fuel cells utilising Shewanella oneidensis as biocatalyst

Objectives To investigate the contribution of direct electron transfer mechanisms to electricity production in microbial fuel cells by physically retaining Shewanella oneidensis cells close to or away from the anode electrode. Results A maximum power output of 114 ± 6 mWm−2 was obtained when cells were retained close to the anode using a dialysis membrane. This was 3.5 times more than when the cells were separated away from the anode. Without the membrane the maximum power output was 129 ± 6 mWm−2. The direct mechanisms of electron transfer contributed significantly to overall electron transfer from S. oneidensis to electrodes, a result that was corroborated by another experiment where S. oneidensis cells were entrapped in alginate gels. Conclusion S. oneidensis transfers electrons primarily by direct electron transfer as opposed to mediated electron transfer.