569 research outputs found
Lactate signalling regulates fungal β-glucan masking and immune evasion
AJPB: This work was supported by the European Research Council (STRIFE, ERC- 2009-AdG-249793), The UK Medical Research Council (MR/M026663/1), the UK Biotechnology and Biological Research Council (BB/K017365/1), the Wellcome Trust (080088; 097377). ERB: This work was supported by the UK Biotechnology and Biological Research Council (BB/M014525/1). GMA: Supported by the CNPq-Brazil (Science without Borders fellowship 202976/2014-9). GDB: Wellcome Trust (102705). CAM: This work was supported by the UK Medical Research Council (G0400284). DMM: This work was supported by UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC/K000306/1). NARG/JW: Wellcome Trust (086827, 075470,101873) and Wellcome Trust Strategic Award in Medical Mycology and Fungal Immunology (097377). ALL: This work was supported by the MRC Centre for Medical Mycology and the University of Aberdeen (MR/N006364/1).Peer reviewedPostprin
Corner contributions to holographic entanglement entropy
The entanglement entropy of three-dimensional conformal field theories
contains a universal contribution coming from corners in the entangling
surface. We study these contributions in a holographic framework and, in
particular, we consider the effects of higher curvature interactions in the
bulk gravity theory. We find that for all of our holographic models, the corner
contribution is only modified by an overall factor but the functional
dependence on the opening angle is not modified by the new gravitational
interactions. We also compare the dependence of the corner term on the new
gravitational couplings to that for a number of other physical quantities, and
we show that the ratio of the corner contribution over the central charge
appearing in the two-point function of the stress tensor is a universal
function for all of the holographic theories studied here. Comparing this
holographic result to the analogous functions for free CFT's, we find fairly
good agreement across the full range of the opening angle. However, there is a
precise match in the limit where the entangling surface becomes smooth, i.e.,
the angle approaches , and we conjecture the corresponding ratio is a
universal constant for all three-dimensional conformal field theories. In this
paper, we expand on the holographic calculations in our previous letter
arXiv:1505.04804, where this conjecture was first introduced.Comment: 62 pages, 6 figures, 1 table; v2: minor modifications to match
published version, typos fixe
High locomotor reactivity to novelty is associated with an increased propensity to choose saccharin over cocaine: new insights into the vulnerability to addiction.
Drug addiction is associated with a relative devaluation of natural or socially-valued reinforcers that are unable to divert addicts from seeking and consuming the drug. Before protracted drug exposure, most rats prefer natural rewards, such as saccharin, over cocaine. However, a subpopulation of animals prefer cocaine over natural rewards and are thought to be vulnerable to addiction. Specific behavioral traits have been associated with different dimensions of drug addiction. For example, anxiety predicts loss of control over drug intake whereas sensation seeking and sign-tracking are markers of a greater sensitivity to the rewarding properties of the drug. However, how these behavioral traits predict the disinterest for natural reinforcers remains unknown. In a population of rats, we identified sensation seekers (HR) on the basis of elevated novelty-induced locomotor reactivity, high anxious rats (HA) based on the propensity to avoid open arms in an elevated-plus maze and sign-trackers (ST) that are prone to approach, and interaction with, reward-associated stimuli. Rats were then tested on their preference for saccharin over cocaine in a discrete-trial choice procedure. We show that HR rats display a greater preference for saccharin over cocaine compared with ST and HA whereas the motivation for the drug was comparable between the three groups. The present data suggest that high locomotor reactivity to novelty, or sensation seeking, by predisposing to an increased choice toward non-drug rewards at early stages of drug use history, may prevent the establishment of chronic cocaine use.This work was funded by an INSERM AVENIR and Agence Nationale de la Recherche (ANR) ANR12 SAMA00201 grant to DB, the région Poitou-Charentes, an AXA research fund fellowship to ABR, and a Ministère de la Recherche et de la Technologie grant to NV. AM was supported by the Behavioural and Clinical Neuroscience Institute of Cambridge.This is the accepted manuscript of a paper published in Neuropsychopharmacology (2015) 40, 577–589; doi:10.1038/npp.2014.204; published online 17 September 2014
Drivers of genetic diversity in secondary metabolic gene clusters within a fungal species
Drivers of genetic diversity in secondary metabolic gene clusters within a fungal speciesFilamentous fungi produce a diverse array of secondary metabolites (SMs) critical for defense, virulence, and communication. The metabolic pathways that produce SMs are found in contiguous gene clusters in fungal genomes, an atypical arrangement for metabolic pathways in other eukaryotes. Comparative studies of filamentous fungal species have shown that SM gene clusters are often either highly divergent or uniquely present in one or a handful of species, hampering efforts to determine the genetic basis and evolutionary drivers of SM gene cluster divergence. Here, we examined SM variation in 66 cosmopolitan strains of a single species, the opportunistic human pathogen Aspergillus fumigatus. Investigation of genome-wide within-species variation revealed 5 general types of variation in SM gene clusters: nonfunctional gene polymorphisms; gene gain and loss polymorphisms; whole cluster gain and loss polymorphisms; allelic polymorphisms, in which different alleles corresponded to distinct, nonhomologous clusters; and location polymorphisms, in which a cluster was found to differ in its genomic location across strains. These polymorphisms affect the function of representative A. fumigatus SM gene clusters, such as those involved in the production of gliotoxin, fumigaclavine, and helvolic acid as well as the function of clusters with undefined products. In addition to enabling the identification of polymorphisms, the detection of which requires extensive genome-wide synteny conservation (e.g., mobile gene clusters and nonhomologous cluster alleles), our approach also implicated multiple underlying genetic drivers, including point mutations, recombination, and genomic deletion and insertion events as well as horizontal gene transfer from distant fungi. Finally, most of the variants that we uncover within A. fumigatus have been previously hypothesized to contribute to SM gene cluster diversity across entire fungal classes and phyla. We suggest that the drivers of genetic diversity operating within a fungal species shown here are sufficient to explain SM cluster macroevolutionary patterns.National Science Foundation (grant
number DEB-1442113). Received by AR. U.S.
National Library of Medicine training grant (grant
number 2T15LM007450). Received by ALL.
Conselho Nacional de Desenvolvimento Cientı´fico e
573 Tecnológico. Northern Portugal Regional
Operational Programme (grant number NORTE-01-
0145-FEDER-000013). Received by FR. Fundação
de Amparo à Pesquisa do 572 Estado de São
Paulo. Received by GHG. National Institutes of
Health (grant number R01 AI065728-01). Received
by NPK. National Science Foundation (grant
number IOS-1401682). Received by JHW. The
funders had no role in study design, data collection
and analysis, decision to publish, or preparation of
the manuscript.info:eu-repo/semantics/publishedVersio
Enhanced petrogenic organic carbon oxidation during the Paleocene-Eocene thermal maximum
The Paleocene-Eocene thermal maximum (PETM; ∼56 Ma) is a hyperthermal event associated with the rapid input of carbon into the ocean-atmosphere system. The oxidation of petrogenic organic carbon (OCpetro) may have released additional carbon dioxide (CO2), thereby prolonging the PETM. However, proxy-based estimates of OCpetro oxidation are unavailable due to the lack of suitable techniques. Raman spectroscopy is used to evaluate OCpetro oxidation in modern settings. For the first time, we explore whether Raman spectroscopy can evaluate OCpetro oxidation during the PETM. In the mid-Atlantic Coastal Plain, there is a shift from disordered to graphitised carbon. This is consistent with enhanced oxidation of disordered OCpetro and intensified physical erosion. In the Arctic Ocean, the distribution of graphitised carbon vs. disordered carbon does not change, suggesting limited variability in weathering intensity. Overall, this study provides the first evidence of increased OCpetro oxidation during the PETM, although it was likely not globally uniform. Our work also highlights the utility of Raman spectroscopy as a novel tool to reconstruct OCpetro oxidation in the past
Identification of genes required for soil survival in Burkholderia thailandensis by transposon-directed insertion site sequencing.
Transposon-directed insertion site sequencing was used to identify genes required by Burkholderia thailandensis to survive in plant/soil microcosms. A total of 1,153 genetic loci fulfilled the criteria as being likely to encode survival characteristics. Of these, 203 (17.6 %) were associated with uptake and transport systems; 463 loci (40.1 %) coded for enzymatic properties, 99 of these (21.4 %) had reduction/oxidation functions; 117 (10.1 %) were gene regulation or sensory loci; 61 (5.3 %) encoded structural proteins found in the cell envelope or with enzymatic activities related to it, distinct from these, 46 (4.0 %) were involved in chemotaxis and flagellum, or pilus synthesis; 39 (3.4 %) were transposase enzymes or were bacteriophage-derived; and 30 (2.6 %) were involved in the production of antibiotics or siderophores. Two hundred and twenty genes (19.1 %) encoded hypothetical proteins or those of unknown function. Given the importance of motility and pilus formation in microcosm persistence the nature of the colonization of the rhizosphere was examined by confocal microscopy. Wild type B. thailandensis expressing red fluorescent protein was inoculated into microcosms. Even though the roots had been washed, the bacteria were still present but they were motile with no attachment having taken place, perhaps being retained in a biofilm
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Towards a Critical Sociology of Dominant Ideologies: An Unexpected Reunion between Pierre Bourdieu and Luc Boltanski
This article aims to demonstrate the enduring relevance of Pierre Bourdieu and Luc Boltanski’s ‘La production de l’idéologie dominante’ [‘The production of the dominant ideology’], which was originally published in Actes de la recherche en sciences sociales in 1976. More than three decades later, in 2008, a re-edited version of this study was printed in book format as La production de l’idéologie dominante, which was accompanied by a detailed commentary, written by Luc Boltanski and entitled Rendre la réalité inacceptable. À propos de « La production de l’idéologie dominante » [Making Reality Unacceptable. Comments on ‘The production of the dominant ideology’]. In addition to containing revealing personal anecdotes and providing important sociological insights, this commentary offers an insider account of the genesis of one of the most seminal pieces Boltanski co-wrote with his intellectual father, Bourdieu. In the Anglophone literature on contemporary French sociology, however, the theoretical contributions made both in the original study and in Boltanski’s commentary have received little – if any – serious attention. This article aims to fill this gap in the literature, arguing that these two texts can be regarded not only as forceful reminders of the fact that the ‘dominant ideology thesis’ is far from obsolete but also as essential for understanding both the personal and the intellectual underpinnings of the tension-laden relationship between Bourdieu and Boltanski. Furthermore, this article offers a critical overview of the extent to which the unexpected, and partly posthumous, reunion between ‘the master’ (Bourdieu) and his ‘dissident disciple’ (Boltanski) equips us with powerful conceptual tools, which, whilst illustrating the continuing centrality of ‘ideology critique’, permit us to shed new light on key concerns in contemporary sociology and social theory. Finally, the article seeks to push the debate forward by reflecting upon several issues that are not given sufficient attention by Bourdieu and Boltanski in their otherwise original and insightful enquiry into the complexities characterizing the daily production of ideology
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The impact of self-monitoring in chronic illness on healthcare utilisation: a systematic review of reviews
Background: Self-management interventions have been found to reduce healthcare utilisation in people with long-term conditions, but further work is needed to identify which components of these interventions are most effective. Self-monitoring is one such component and is associated with significant clinical benefits. The aim of this systematic review of reviews is to assess the impact of self-monitoring interventions on healthcare utilisation across a range of chronic illnesses.
Methods: An overview of published systematic reviews and meta-analyses. Multiple databases were searched (MEDLINE, CINAHL, PsycINFO, EMBASE, AMED, EBM and HMIC) along with the reference lists of included reviews. A narrative synthesis was performed, accompanied by calculation of the Corrected Cover Area to understand the impact of overlapping primary research papers.
Results: A total of 17 systematic reviews and meta-analyses across three chronic conditions, heart failure, hypertension and chronic obstructive pulmonary disease, were included. Self-monitoring was associated with significant reductions in hospitalisation and re-admissions to hospital.
Conclusions: Self-monitoring has the potential to reduce the pressure placed on secondary care services, but this may lead to increase in services elsewhere in the system. Further work is needed to determine how these findings affect healthcare costs
Deployable Laboratory Response to Influenza Pandemic; PCR Assay Field Trials and Comparison with Reference Methods
Background: The influenza A/H1N1/09 pandemic spread quickly during the Southern Hemisphere winter in 2009 and reached epidemic proportions within weeks of the official WHO alert. Vulnerable population groups included indigenous Australians and remote northern population centres visited by international travellers. At the height of the Australian epidemic a large number of troops converged on a training area in northern Australia for an international exercise, raising
concerns about their potential exposure to the emerging influenza threat before, during and immediately after their arrival in the area. Influenza A/H1N1/09 became the dominant seasonal variant and returned to Australia during the Southern winter the following year.
Methods: A duplex nucleic acid amplification assay was developed within weeks of the first WHO influenza pandemic alert,
demonstrated in northwestern Australia shortly afterwards and deployed as part of the pathology support for a field
hospital during a military exercise during the initial epidemic surge in June 2009.
Results: The nucleic acid amplification assay was twice as sensitive as a point of care influenza immunoassay, as specific but a little less sensitive than the reference laboratory nucleic acid amplification assay. Repetition of the field assay with blinded clinical samples obtained during the 2010 winter influenza season demonstrated a 91.7% congruence with the reference laboratory method.
Conclusions: Rapid in-house development of a deployable epidemic influenza assay allowed a flexible laboratory response, effective targeting of limited disease control resources in an austere military environment, and provided the public health laboratory service with a set of verification tools for resource-limited settings. The assay method was suitable for rapid deployment in time for the 2010 Northern winter
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Helminth burden and ecological factors associated with alterations in wild host gastrointestinal microbiota
Infection by gastrointestinal helminths of humans, livestock and wild animals is common, but the impact of such endoparasites on wild hosts and their gut microbiota represents an important overlooked component of population dynamics. Wild host gut microbiota and endoparasites occupy the same physical niche spaces with both affecting host nutrition and health. However, associations between the two are poorly understood. Here we used the commonly parasitized European shag (Phalacrocorax aristotelis) as a model wild host. Forty live adults from the same colony were sampled. Endoscopy was employed to quantify helminth infection in situ. Microbiota from the significantly distinct proventriculus (site of infection), cloacal and faecal gastrointestinal tract microbiomes were characterised using 16S rRNA gene-targeted high-throughput sequencing. We found increasingly strong associations between helminth infection and microbiota composition progressing away from the site of infection, observing a pronounced dysbiosis in microbiota when samples were partitioned into high- and low-burden groups. We posit this dysbiosis is predominately explained by helminths inducing an anti-inflammatory environment in the proventriculus, diverting host immune responses away from themselves. This study, within live wild animals, provides a vital foundation to better understand the mechanisms that underpin the three-way relationship between helminths, microbiota and hosts
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