Evolutionary diversification of the RomR protein of the invasive deltaproteobacterium, Bdellovibrio bacteriovorus

This is the final version. Available on open access from Nature Research via the DOI in this recordBdellovibrio bacteriovorus is a predatory deltaproteobacterium that encounters individual Gram-negative prey bacteria with gliding or swimming motility, and then is able to invade such prey cells via type IVa pilus-dependent mechanisms. Movement control (pili or gliding) in other deltaproteobacteria, such as the pack hunting Myxococcus xanthus, uses a response regulator protein, RomRMx (which dynamically relocalises between the cell poles) and a GTPase, MglAMx, previously postulated as an interface between the FrzMx chemosensory system and gliding or pilus-motility apparatus, to produce regulated bidirectional motility. In contrast, B. bacteriovorus predation is a more singular encounter between a lone predator and prey; contact is always via the piliated, non-flagellar pole of the predator, involving MglABd, but no Frz system. In this new study, tracking fluorescent RomRBd microscopically during predatory growth shows that it does not dynamically relocalise, in contrast to the M. xanthus protein; instead having possible roles in growth events. Furthermore, transcriptional start analysis, site-directed mutagenesis and bacterial two-hybrid interaction studies, indicate an evolutionary loss of RomRBd activation (via receiver domain phosphorylation) in this lone hunting bacterium, demonstrating divergence from its bipolar role in motility in pack-hunting M. xanthus and further evolution that may differentiate lone from pack predators.Leverhulme TrustMedical Research Council (MRC)Biotechnology and Biological Sciences Research Council (BBSRC

Can participatory mapping activate spatial and political practices? Mapping popular resistance and dwelling practices in Bogotá eastern hills

Within the wider ongoing debate of Participatory Action Research, this paper interrogates the capacity of participatory mapping not just as a means to tap into plural knowledges over and emanating from specific geographies but rather to disrupt exclusionary constructions of space and place and the reproduction of the governing relationships that cause inequality. Focusing on a participatory mapping experience undertaken by the authors in collaboration with local residents in the steep slopes of Bogota’s eastern hills – an area threatened by forced evictions in the name of ecological preservation and risk protection arguments - we explore why and under what conditions participatory mapping might have the potential to disrupt conflicting interpretations of place and space held both by local residents and state agencies, which in turn can open the room to rework what types of interventions are actually needed and why. We hypothesise that this depends on the extent to which mapping can abridge the different scales at which the state and marginalised communities make sense of a site historically underpinned by different forms of spatial myopia and territorial stigma. This is in our view not just a consequence of the application of participatory mapping techniques per se, but depends on the way in which mapping is used to expand the political space in which different conceptions of a territory can effectively talk to each other

Essential thalamic contribution to slow waves of natural sleep

Slow waves represent one of the prominent EEG signatures of non-rapid eye movement (non-REM) sleep and are thought to play an important role in the cellular and network plasticity that occurs during this behavioral state. These slow waves of natural sleep are currently considered to be exclusively generated by intrinsic and synaptic mechanisms within neocortical territories, although a role for the thalamus in this key physiological rhythm has been suggested but never demonstrated. Combining neuronal ensemble recordings, microdialysis, and optogenetics, here we show that the block of the thalamic output to the neocortex markedly (up to 50%) decreases the frequency of slow waves recorded during non-REM sleep in freely moving, naturally sleeping-waking rats. A smaller volume of thalamic inactivation than during sleep is required for observing similar effects on EEG slow waves recorded during anesthesia, a condition in which both bursts and single action potentials of thalamocortical neurons are almost exclusively dependent on T-type calcium channels. Thalamic inactivation more strongly reduces spindles than slow waves during both anesthesia and natural sleep. Moreover, selective excitation of thalamocortical neurons strongly entrains EEG slow waves in a narrow frequency band (0.75-1.5 Hz) only when thalamic T-type calcium channels are functionally active. These results demonstrate that the thalamus finely tunes the frequency of slow waves during non-REM sleep and anesthesia, and thus provide the first conclusive evidence that a dynamic interplay of the neocortical and thalamic oscillators of slow waves is required for the full expression of this key physiological EEG rhythm

Abelian-Higgs and Vortices from ABJM: towards a string realization of AdS/CMT

We present ans\"{a}tze that reduce the mass-deformed ABJM model to gauged Abelian scalar theories, using the fuzzy sphere matrices $G^\alpha$. One such reduction gives a Toda system, for which we find a new type of nonabelian vortex. Another gives the standard Abelian-Higgs model, thereby allowing us to embed all the usual (multi-)vortex solutions of the latter into the ABJM model. By turning off the mass deformation at the level of the reduced model, we can also continuously deform to the massive $\phi^4$ theory in the massless ABJM case. In this way we can embed the Landau-Ginzburg model into the AdS/CFT correspondence as a consistent truncation of ABJM. In this context, the mass deformation parameter $\mu$ and a field VEV $$ act as $g$ and $g_c$ respectively, leading to a well-motivated AdS/CMT construction from string theory. To further this particular point, we propose a simple model for the condensed matter field theory that leads to an approximate description for the ABJM abelianization. Finally, we also find some BPS solutions to the mass-deformed ABJM model with a spacetime interpretation as an M2-brane ending on a spherical M5-brane.Comment: 43 pages, latex, explanations added in the introduction, end of section 4, and on page 2

Social marketing and healthy eating : Findings from young people in Greece

This document is the Accepted Manuscript version. The final publication is available at Springer via http://dx.doi.org/10.1007/s12208-013-0112-xGreece has high rates of obesity and non-communicable diseases owing to poor dietary choices. This research provides lessons for social marketing to tackle the severe nutrition-related problems in this country by obtaining insight into the eating behaviour of young adults aged 18–23. Also, the main behavioural theories used to inform the research are critically discussed. The research was conducted in Athens. Nine focus groups with young adults from eight educational institutions were conducted and fifty-nine participants’ views towards eating habits, healthy eating and the factors that affect their food choices were explored. The study found that the participants adopted unhealthier nutritional habits after enrolment. Motivations for healthy eating were good health, appearance and psychological consequences, while barriers included lack of time, fast-food availability and taste, peer pressure, lack of knowledge and lack of family support. Participants reported lack of supportive environments when deciding on food choices. Based on the findings, recommendations about the development of the basic 4Ps of the marketing mix, as well as of a fifth P, for Policy are proposedPeer reviewe

Probing the Space of Toric Quiver Theories

We demonstrate a practical and efficient method for generating toric Calabi-Yau quiver theories, applicable to both D3 and M2 brane world-volume physics. A new analytic method is presented at low order parametres and an algorithm for the general case is developed which has polynomial complexity in the number of edges in the quiver. Using this algorithm, carefully implemented, we classify the quiver diagram and assign possible superpotentials for various small values of the number of edges and nodes. We examine some preliminary statistics on this space of toric quiver theories

Interaction between M2-branes and Bulk Form Fields

We construct the interaction terms between the world-volume fields of multiple M2-branes and the 3- and 6-form fields in the context of ABJM theory with U($N$)$\times$U($N$) gauge symmetry. A consistency check is made in the simplest case of a single M2-brane, i.e, our construction matches the known effective action of M2-brane coupled to antisymmetric 3-form field. We show that when dimensionally reduced, our couplings coincide with the effective action of D2-branes coupled to R-R 3- and 5-form fields in type IIA string theory. We also comment on the relation between a coupling with a specific 6-form field configuration and the supersymmetry preserving mass deformation in ABJM theory.Comment: 30 pages, version to appear in JHE

Skull morphological variation in a British stranded population of false killer whale (Pseudorca crassidens, Owen 1846): a 3D geometric morphometric approach

The false killer whale (Pseudorca crassidens (Owen, 1846)) is a globally distributed delphinid that shows geographical differentiation in its skull morphology. We explored cranial morphological variation in a sample of 85 skulls belonging to a mixed sex population stranded in the Moray Firth, Scotland, in 1927. A three-dimensional digitizer (Microscribe 2GX) was used to record 37 anatomical landmarks on the cranium and 25 on the mandible to investigate size and shape variation and to explore sexual dimorphism using geometric morphometric. Males showed greater overall skull size than females, whereas no sexual dimorphism could be identified in cranial and mandibular shape. Allometric skull changes occurred in parallel for both males and females, supporting the lack of sexual shape dimorphism for this particular sample. Also, fluctuating asymmetry did not differ between crania of males and females. This study confirms the absence of sexual shape dimorphism and the presence of a sexual size dimorphism in this false killer whale population

Near-source passive sampling for monitoring viral outbreaks within a university residential setting

\ua9 2024 Cambridge University Press. All rights reserved. Wastewater based epidemiology (WBE) has proven to be a powerful tool for the population-level monitoring of pathogens, particularly SARS-CoV-2. For accurate and timely assessment, several wastewater sampling regimes and methods of viral concentration have been investigated, mainly targeting SARS-CoV-2. However, the use of passive samplers in near-source environments for a range of viruses in wastewater is yet under-investigated. To address this, near-source passive samples were taken at four locations targeting student halls of residence. These were chosen as an exemplar due to their high population density and perceived risk of disease transmission. Viruses investigated were SARS-CoV-2 and its variants of concern (VOCs), influenza-A and B viruses and enteroviruses. Sampling was conducted either in the morning, where passive samplers were in place overnight (17 h) and during the day, where samplers remained in the sewer for 7 h. We demonstrated the usefulness of near-source passive sampling for the detection of VOCs using qPCR and Next Generation Sequencing. Furthermore, several outbreaks of influenza-A and sporadic outbreaks of enteroviruses (some associated with enterovirus D68 and coxsackieviruses) were identified amongst the resident student population, providing evidence of the usefulness of near-source, in-sewer sampling for monitoring the health of high population density communities

On Non-linear Action for Gauged M2-brane

We propose a non-linear extension of U(1) \times U(1) (abelian) ABJM model including T_{M2} (higher derivative) corrections. The action proposed here is expected to describe a single M2-brane proving C^4/Z_k target space. The model includes couplings with the 3-form background in the eleven-dimensional supergravity which is consistent with the orbifold projection. We show that the novel higgs mechanism proposed by Mukhi and Papageorgakis does work even in the presence of higher derivative corrections and couplings with the background field, giving the correct structure of the Dirac-Born-Infeld action with Wess-Zumino term for a D2-brane. We also find half BPS solutions in the full non-linear theory which is interpreted as an another M2-brane intersecting with the original M2-brane. A possible generalization to U(N) \times U(N) gauge group is briefly discussed.Comment: 19 pages, no figure, references added, typos correcte