42 research outputs found
Linear broadening of the confining string in Yang-Mills theory at low temperature
The logarithmic broadening predicted by the systematic low-energy effective
field theory for the confining string has recently been verified in numerical
simulations of (2+1)-d SU(2) lattice Yang-Mills theory at zero temperature. The
same effective theory predicts linear broadening of the string at low non-zero
temperature. In this paper, we verify this prediction by comparison with very
precise Monte Carlo data. The comparison involves no additional adjustable
parameters, because the low-energy constants of the effective theory have
already been fixed at zero temperature. It yields very good agreement between
the underlying Yang-Mills theory and the effective string theory.Comment: 10 pages, 3 figures. Version published in JHEP; improved figures 1
and
Mach-Zehnder-Fano interferometer
We introduce a concept of the Mach-Zehnder-Fano interferometer by inserting a
cavity exhibiting Fano resonance into a conventional interferometer. By
employing the scattering-matrix approach, we demonstrate that the transmission
is sensitive to a position of the cavity such that an asymmetric structure
exhibits a series of narrow resonances with almost perfect reflection. We
discuss how to implement this novel geometry in two-dimensional photonic
crystals and use direct numerical simulations to demonstrate novel regimes of
the resonant transmission and reflection.Comment: 3 pages, 3 figure
Single neuron transcriptomics identify SRSF/ SR protein B52 as a regulator of axon growth and Choline acetyltransferase splicing.
We removed single identified neurons from living Drosophila embryos to gain insight into the transcriptional control of developing neuronal networks. The microarray analysis of the transcriptome of two sibling neurons revealed seven differentially expressed transcripts between both neurons (threshold: log(2)1.4). One transcript encodes the RNA splicing factor B52. Loss of B52 increases growth of axon branches. B52 function is also required for Choline acetyltransferase (ChAT ) splicing. At the end of embryogenesis, loss of B52 function impedes splicing of ChAT, reduces acetylcholine synthesis, and extends the period of uncoordinated muscle twitches during larval hatching. ChAT regulation by SRSF proteins may be a conserved feature since changes in SRSF5 expression and increased acetylcholine levels in brains of bipolar disease patients have been reported recently
The PLIN4 Variant rs8887 Modulates Obesity Related Phenotypes in Humans through Creation of a Novel miR-522 Seed Site
PLIN4 is a member of the PAT family of lipid storage droplet
(LSD) proteins. Associations between seven single nucleotide polymorphisms
(SNPs) at human PLIN4 with obesity related phenotypes were
investigated using meta-analysis followed by a determination if these phenotypes
are modulated by interactions between PLIN4 SNPs and dietary
PUFA. Samples consisted of subjects from two populations of European ancestry.
We demonstrated association of rs8887 with anthropometrics. Meta-analysis
demonstrated significant interactions between the rs8887 minor allele with PUFA
n3 modulating anthropometrics. rs884164 showed interaction with both n3 and n6
PUFA modulating anthropometric and lipid phenotypes. In silico
analysis of the PLIN4 3′UTR sequence surrounding the
rs8887 minor A allele predicted a seed site for the human microRNA-522
(miR-522), suggesting a functional mechanism. Our data showed that a PLIN4
3′UTR luciferase reporter carrying the A allele of rs8887 was reduced in
response to miR-522 mimics compared to the G allele. These results suggest
variation at the PLIN4 locus, and its interaction with PUFA as
a modulator of obesity related phenotypes, acts in part through creation of a
miR-522 regulatory site
Stressed out symbiotes:hypotheses for the influence of abiotic stress on arbuscular mycorrhizal fungi
Abiotic stress is a widespread threat to both plant and soil communities. Arbuscular mycorrhizal (AM) fungi can alleviate effects of abiotic stress by improving host plant stress tolerance, but the direct effects of abiotic stress on AM fungi are less well understood. We propose two hypotheses predicting how AM fungi will respond to abiotic stress. The stress exclusion hypothesis predicts that AM fungal abundance and diversity will decrease with persistent abiotic stress. The mycorrhizal stress adaptation hypothesis predicts that AM fungi will evolve in response to abiotic stress to maintain their fitness. We conclude that abiotic stress can have effects on AM fungi independent of the effects on the host plant. AM fungal communities will change in composition in response to abiotic stress, which may mean the loss of important individual species. This could alter feedbacks to the plant community and beyond. AM fungi will adapt to abiotic stress independent of their host plant. The adaptation of AM fungi to abiotic stress should allow the maintenance of the plant-AM fungal mutualism in the face of changing climates. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00442-016-3673-7) contains supplementary material, which is available to authorized users
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference