250 research outputs found
Non-reversibility and self-joinings of higher orders for ergodic flows
By studying the weak closure of multidimensional off-diagonal self-joinings
we provide a criterion for non-isomorphism of a flow with its inverse, hence
the non-reversibility of a flow. This is applied to special flows over rigid
automorphisms. In particular, we apply the criterion to special flows over
irrational rotations, providing a large class of non-reversible flows,
including some analytic reparametrizations of linear flows on the two torus, so
called von Neumann's flows and some special flows with piecewise polynomial
roof functions.. A topological counterpart is also developed with the full
solution of the problem of the topological self-similarity of continuous
special flows over irrational rotations. This yields examples of continuous
special flows over irrational rotations without topological self-similarities
and having all non-zero real numbers as scales of measure-theoretic
self-similarities.Comment: 49 pages, 2 figur
Mild mixing property for special flows under piecewise constant functions
We give a condition on a piecewise constant roof function and an irrational
rotation by on the circle to give rise to a special flow having the
mild mixing property. Such flows will also satisfy Ratner's property. As a
consequence we obtain a class of mildly mixing singular flows on the two-torus
that arise from quasi-periodic Hamiltonians flows by velocity changes.Comment: Accepted for publication in Discrete Contin. Dyn. Sys
A realization of the Hecke algebra on the space of period functions for Gamma_0(n)
The standard realization of the Hecke algebra on classical holomorphic cusp
forms and the corresponding period polynomials is well known. In this article
we consider a nonstandard realization of the Hecke algebra on Maass cusp forms
for the Hecke congruence subgroups Gamma_0(n). We show that the vector valued
period functions derived recently by Hilgert, Mayer and Movasati as special
eigenfunctions of the transfer operator for Gamma_0(n) are indeed related to
the Maass cusp forms for these groups. This leads also to a simple
interpretation of the ``Hecke like'' operators of these authors in terms of the
aforementioned non standard realization of the Hecke algebra on the space of
vector valued period functions.Comment: 30 pages; corrected typos and fixed incomplete proofs in section
Corticosteroid treatment is associated with increased filamentous fungal burden in allergic fungal disease
Background
Allergic diseases caused by fungi are common. The best understood conditions are allergic
bronchopulmonaryaspergillosis (ABPA) and severe asthma with fungal sensitisation (SAFS).
Our knowledge of the fungal microbiome (mycobiome) is limited to a few studies involving
healthy individuals, asthmatics and smokers. No study has yet examined the mycobiome in
fungal lung disease.
Objectives
The main aim of this study was to determine the mycobiome in lungs of individuals with well
characterised fungal disease. A secondary objective was to determine possible effects of
treatment on the mycobiome.
Methods
After bronchoscopy, ITS1 DNA was amplified and sequenced and fungal load determined by
RT-PCR. Clinical and treatment variables were correlated with the main species identified.
ABPA (n=16), SAFS (n=16), severe asthma not sensitised to fungi, (n=9), mild asthma
patients(n=7) and 10 healthy controls were studied.
Results
The mycobiome was highly varied with severe asthmatics carrying higher loads of fungus.
Healthy individuals had low fungal loads, mostly poorly characterised Malasezziales.The
most common fungus in asthmatics was Aspergillus fumigatus complex and this taxon
accounted for the increased burden of fungus in the high level samples. Corticosteroid
treatment was significantly associated with increased fungal load (p<0.01).
Conclusions
The mycobiome is highly variable. Highest loads of fungus are observed in severe asthmatics
and the most common fungus is Aspergillus fumigatus complex. Individuals receiving steroid
therapy had significantly higher levels of Aspergillus and total fungus in their BAL
Laser-related spectroscopic parameters of NV colour centres in diamond
One of the most common impurities in synthetic diamond is single substitutional nitrogen, which is incorporated in the diamond lattice substituting a carbon atom [1]. If the nitrogen is adjacent to a vacancy in the diamond lattice, it forms the nitrogen-vacancy (NV) colour centre (CC) [1]. The negatively charged state of this CC, NV-, is particularly well studied since its quantum properties are suitable for applications such as quantum information processing, single-photon sources and optical magnetometry [2]. NV CCs in the neutral state (NV0) are less widely studied. This CC exhibits broadband luminescence at slightly shorter wavelengths than NV-, and hence is also potentially of interest for tuneable and ultrafast visible laser applications. In this report, we present a detailed study of the laser-related spectroscopic properties of a diamond containing NV0 and NV- CCs
New paradigms for understanding and step changes in treating active and chronic, persistent apicomplexan infections
Toxoplasma gondii, the most common parasitic infection of human brain and eye, persists across lifetimes, can progressively damage sight, and is currently incurable. New, curative medicines are needed urgently. Herein, we develop novel models to facilitate drug development: EGS strain T. gondii forms cysts in vitro that induce oocysts in cats, the gold standard criterion for cysts. These cysts highly express cytochrome b. Using these models, we envisioned, and then created, novel 4-(1H)-quinolone scaffolds that target the cytochrome bc1 complex Qi site, of which, a substituted 5,6,7,8-tetrahydroquinolin-4-one inhibits active infection (IC50, 30 nM) and cysts (IC50, 4 μM) in vitro, and in vivo (25 mg/kg), and drug resistant Plasmodium falciparum (IC50, <30 nM), with clinically relevant synergy. Mutant yeast and co-crystallographic studies demonstrate binding to the bc1 complex Qi site. Our results have direct impact on improving outcomes for those with toxoplasmosis, malaria, and ~2 billion persons chronically infected with encysted bradyzoites
Author Correction: New paradigms for understanding and step changes in treating active and chronic, persistent apicomplexan infections
Correction to: Scientific Reports https://doi.org/10.1038/srep29179, published online 14 July 201
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