Directing cell migration using micropatterned and dynamically adhesive polymer brushes

This work was funded by the BBSRC, New Investigator Award (BB/J000914/1)

Characterization of the fecal microbiota of pigs before and after inoculation with "Brachyspira hampsonii".

Brachyspira hampsonii causes disease indistinguishable from swine dysentery, and the structure of the intestinal microbiome likely plays a role in determining susceptibility of individual pigs to infection and development of clinical disease. The objectives of the current study were to determine if the pre-inoculation fecal microbiota differed between inoculated pigs that did (INOC MH) or did not (INOC non-MH) develop mucohaemorrhagic diarrhea following challenge with B. hampsonii , and to quantify changes in the structure of the microbiome following development of clinical disease. Fecal microbiota profiles were generated based on amplification and sequencing of the cpn60 universal target sequence from 89 samples from 18 pigs collected at -8, -5, -3 and 0 days post-inoculation, and at termination. No significant differences in richness, diversity or taxonomic composition distinguished the pre-inoculation microbiomes of INOC MH and INOC non-MH pigs. However, the development of bloody diarrhea in inoculated pigs was associated with perturbation of the microbiota relative to INOC non-MH or sham-inoculated control pigs. Specifically, the fecal microbiota of INOC MH pigs was less dense (fewer total 16S rRNA copies per gram of feces), and had a lower Bacteroidetes:Firmicutes ratio. Further investigation of the potential long-term effects of Brachyspira disease on intestinal health and performance is warranted

On three-point correlation functions in the gauge/gravity duality

We study the effect of marginal and irrelevant deformations on the renormalization of operators near a CFT fixed point. New divergences in a given operator are determined by its OPE with the operator D that generates the deformation. This provides a scheme to compute the couplings a_DAB between the operator D and two arbitrary operators O_A and O_B. We exemplify for the case of N=4 SYM, considering the simplest case of the exact Lagrangian deformation. In this case the deformed anomalous dimension matrix is determined by the derivative of the anomalous dimension matrix with respect to the coupling. We use integrability techniques to compute the one-loop couplings a_LAB between the Lagrangian and two distinct large operators built with Magnons, in the SU(2) sector of the theory. Then we consider a_DAA at strong coupling, and show how to compute it using the gauge/gravity duality, when D is a chiral operator dual to any supergravity field and O_A is dual to a heavy string state. We exemplify for the Lagrangian and operators O_A dual to heavy string states, showing agreement with the prediction derived from the renormalization group arguments

Polarised black holes in ABJM

We numerically construct asymptotically $AdS_4$ solutions to Einstein-Maxwell-dilaton theory. These have a dipolar electrostatic potential turned on at the conformal boundary $S^2\times \mathbb{R}_t$. We find two classes of geometries: $AdS$ soliton solutions that encode the full backreaction of the electric field on the $AdS$ geometry without a horizon, and neutral black holes that are "polarised" by the dipolar potential. For a certain range of the electric field $\mathcal{E}$, we find two distinct branches of the $AdS$ soliton that exist for the same value of $\mathcal{E}$. For the black hole, we find either two or four branches depending on the value of the electric field and horizon temperature. These branches meet at critical values of the electric field and impose a maximum value of $\mathcal{E}$ that should be reflected in the dual field theory. For both the soliton and black hole geometries, we study boundary data such as the stress tensor. For the black hole, we also consider horizon observables such as the entropy. At finite temperature, we consider the Gibbs free energy for both phases and determine the phase transition between them. We find that the $AdS$ soliton dominates at low temperature for an electric field up to the maximum value. Using the gauge/gravity duality, we propose that these solutions are dual to deformed ABJM theory and compute the corresponding weak coupling phase diagram

Population dynamics, life stage and ecological modeling in Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae)

In this study we investigated the population dynamics of Chrysomya albiceps (Wiedemann) with laboratory experiments, employing survival analysis and stage structure mathematical models, emphasizing survival among life stages. The study also assessed the theoretical influence of density dependence and cannibalism during immature stages, on the population dynamics of the species. The survival curves were similar, indicating that populations of C. albiceps exhibit the same pattern of survival among life stages. A strong nonlinear trend was observed, suggesting density dependence, acting during the first life stages of C. albiceps. The time-series simulations produced chaotic oscillations for all life stages, and the cannibalism did not produce qualitative changes in the dynamic behavior. The bifurcation analysis shows that for low values for survival, the population reaches a stable equilibrium, but the cannibalism results in chaotic oscillations practically over all the parametric space. The implications of the patterns of dynamic behavior observed are discussed.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)WACGCNPqFAPES

Polarised black holes in AdS

© 2016 IOP Publishing Ltd. We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global AdS 4 with conformal boundary . At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic AdS behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an AdS soliton that includes the full backreaction of the electric field on the AdS geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both AdS soliton and black hole phases. The corresponding phase diagram generalizes the Hawking-Page phase transition. The AdS soliton dominates the low temperature phase and the black hole the high temperature phase, with a critical temperature that decreases as the external electric field increases. Finally, we consider the simple case of a free charged scalar field on with conformal coupling. For a field in the SU(N ) adjoint representation we compare the phase diagram with the above gravitational system

Informant Personality Is Associated With Ratings of Memory Problems in Older Adults

Memory complaints are a key diagnostic criterion for dementia and Mild Cognitive Impairment. Rating scales can be used to capture information about individuals’ memory problems from informants such as family members. However, problems with scale reliability suggest that individual differences influence the ratings informants provide. This project tested whether informants’ neuroticism was associated with their ratings of an older adult’s memory. In an online study, 293 volunteers completed a Five Factor personality questionnaire and used two memory questionnaires to provide ratings of memory problems in an older individual they knew well. Rater neuroticism correlated positively with estimates of memory problems: more neurotic informants provided higher estimates of memory difficulties in the person they were rating. A second study replicated this finding with 786 volunteers and another widely used memory measure, the AD8. In both studies, exploratory analyses suggested the effect size was large enough to impact on clinical practice

The N terminus of the peroxisomal cycling receptor, Pex5p, is required for redirecting the peroxisome-associated peroxin back to the cytosol

Most newly synthesized peroxisomal matrix proteins are transported to the organelle by Pex5p, a remarkable multidomain protein involved in an intricate network of transient protein-protein interactions. Presently, our knowledge regarding the structure/function of amino acid residues 118 to the very last residue of mammalian Pex5p is quite vast. Indeed, the cargo-protein receptor domain as well as the binding sites for several peroxins have all been mapped to this region of Pex5p. In contrast, structural/functional data regarding the first 117 amino acid residues of Pex5p are still scarce. Here we show that a truncated Pex5p lacking the first 110 amino acid residues (DeltaN110-Pex5p) displays exactly the peroxisomal import properties of the full-length peroxin implying that this N-terminal domain is involved neither in cargo-protein binding nor in the docking/translocation step of the Pex5p-cargo protein complex at the peroxisomal membrane. However, the ATP-dependent export step of DeltaN110-Pex5p from the peroxisomal membrane is completely blocked, a phenomenon that was also observed for a Pex5p version lacking just the first 17 amino acid residues but not for a truncated protein comprising amino acid residues 1-324 of Pex5p. By exploring the unique properties of DeltaN110-Pex5p, the effect of temperature on the import/export kinetics of Pex5p was characterized. Our data indicate that the export step of Pex5p from the peroxisomal compartment ( in contrast with its insertion into the organelle membrane) is highly dependent on the temperature

The importance of serological assays in diagnosing acute pulmonary histoplasmosis

Histoplasmosis is a systemic mycosis caused by inhalation of Histoplasma capsulatum microconidia. The disease does not normally affect immunocompetent individuals after a single, transient inhalation exposure. However, longer exposure may cause chronic or disseminated acute pulmonary infection. Herein, we report the case of a 24-year-old immunocompetent patient, who presented fever, cough and dyspnea for one month. The chest radiography revealed interstitial infiltrate and diffuse micronodules. The patient reported having had close and prolonged contact with bats. Diagnosis was confirmed by positive double immunodifusion and immunoblotting assays. She was treated with ketoconazole (400 mg) and there was complete resolution of the disease